HOPKINS JOHN (US)
GREENLEE JORDAN (US)
US20200303300A1 | 2020-09-24 | |||
US20100224962A1 | 2010-09-09 | |||
US20200328226A1 | 2020-10-15 | |||
US20180268902A1 | 2018-09-20 | |||
US20200273881A1 | 2020-08-27 |
CLAIMS l/we claim, 1 . An integrated assembly, comprising: a memory region and another region adjacent the memory region; channel-material-pillars arranged within the memory region, and conductive posts arranged within said other region; a source structure coupled to lower regions of the channel-material-pi liars; a panel extending across the memory region and said other region, and separating a first memory-block-region from a second memory-block-region; doped-semiconductor-material directly adjacent to the panel within the memory region and the other region; the doped- semiconductor-material being at least part of the source structure within the memory region; first liners adjacent lower regions of the conductive posts and laterally surrounding the lower regions of the conductive posts; the first liners being between the conductive posts and the doped- semiconductor-material; and second liners directly adjacent to upper regions of the conductive posts and laterally surrounding the upper regions of the conductive posts. 2. The integrated assembly of claim 1 wherein at least some of the conductive posts are coupled with logic circuitry under said at least some of the conductive posts. 36 3. The integrated assembly of claim 2 comprising SGD devices operatively proximate the channel-material-pillars; and wherein the SGD devices are coupled to the conductive posts, and are coupled to the logic circuitry through the conductive posts. 4. The integrated assembly of claim 1 wherein the doped- semiconductor-material comprises silicon. 5. The integrated assembly of claim 1 wherein the first liners comprise only a single homogeneous composition. 6. The integrated assembly of claim 1 wherein the first liners comprise a laminate of two or more different compositions. 7. The integrated assembly of claim 1 wherein the first liners comprise carbon-doped silicon oxide. The integrated assembly of claim 1 wherein the first liners comprise carbon-doped silicon nitride. 9. The integrated assembly of claim 1 wherein the first liners comprise SiON, where the chemical formula indicates primary constituents rather than a specific stoichiometry. 37 10. The integrated assembly of claim 1 wherein the first liners consist essentially of carbon. 1 1 . The integrated assembly of claim 1 comprising vertically- stacked conductive levels over the memory region and the other region; and wherein the channel-material-pillars and the posts extend through the vertically-stacked conductive levels. 12. The integrated assembly of claim 11 wherein upper conductive levels of the vertically-stacked conductive levels are memory cell levels, and wherein a lower conductive level of the vertically-stacked conductive levels is a select device level. 13. The integrated assembly of claim 11 wherein the conductive levels are spaced from the upper regions of the conductive posts by the second liners. 14. The integrated assembly of claim 13 wherein the second liners comprise silicon dioxide. 15. An integrated assembly, comprising: a first memory region, a second memory region offset from the first memory region, and an intermediate region between the first and second memory regions; first channel-material-pillars arranged within the first memory region; second channel-material-pillars arranged within the second memory region; conductive posts arranged within the intermediate region; a panel extending across the first memory region, the intermediate region and the second memory region; the panel being laterally between a first memory-block-region and a second memory- block-region; doped-semiconductor-material within the first memory region, the second memory region and the intermediate region, and being directly adjacent to the panel; the doped-semiconductor- material being at least part of conductive source structures within the first and second memory regions; insulative rings laterally surrounding lower regions of the conductive posts and being between the conductive posts and the doped-semiconductor-material; the doped-semiconductor-material directly contacting outer edges of the insulative rings; and insulative liners along upper regions of the conductive posts and directly contacting the upper regions of the conductive posts. 16. The integrated assembly of claim 15 wherein the insulative rings comprise carbon-doped silicon oxide. 17. The integrated assembly of claim 15 wherein the insulative rings comprise carbon-doped silicon nitride. 18. The integrated assembly of claim 15 wherein the insulative rings comprise SiON, where the chemical formula indicates primary constituents rather than a specific stoichiometry. 19. The integrated assembly of claim 15 wherein the insulative rings consist essentially of carbon. 20. The integrated assembly of claim 15 wherein the doped- semiconductor-material comprises silicon. 21 . The integrated assembly of claim 15 wherein components are operatively proximate the channel-material-pillars and are also coupled with the conductive posts, and wherein the conductive posts are electrically coupled with logic circuitry. 22. A method of forming an integrated assembly, comprising: forming a construction to include a first memory region, a second memory region laterally offset from the first memory region, and an intermediate region laterally between the first and second memory regions; the construction including a first stack extending across the first memory region, the second memory region and the intermediate region; the first stack comprising alternating semiconductor-material-containing regions and intervening regions; there being at least three of the semiconductor-material-containing regions, with one of the semiconductor-material-containing regions being a central semiconductor-material-containing region and being vertically between two others of the semiconductor-materialcontaining regions; the construction including conductive islands under the first stack within the intermediate region; forming first openings extending through the first stack within the intermediate region and to the conductive islands; lining sidewall surfaces of the first openings with protective liners to thereby form lined first openings; forming sacrificial plugs within the lined first openings; the sacrificial plugs comprising first sacrificial material; forming a second stack over the first stack and the sacrificial plugs; the second stack extending across the first memory region, the second memory region and the intermediate region; the second stack comprising alternating first and second levels, with the first levels comprising second sacrificial material and the second levels comprising insulative material; forming pillars extending through the second stacks of the first and second memory regions and at least partially into the first stacks of the first and second memory regions, the pillars including cell materials and channel material; forming second openings extending through the second stack to the sacrificial plugs; removing the sacrificial plugs; 41 forming insulative liners along sidewalls of the second openings to thereby form lined second openings; forming conductive posts within the lined second openings; forming a slit-opening to pass through the second stack and to the central semiconductor-material-containing region of the first stack; the slit-opening extending across the first memory region, the intermediate region and the second memory region; removing the central semiconductor-material-containing region from within the first memory region, the intermediate region and the second memory region with one or more etchants flowed into the slit-opening, the protective liners being resistant to said one or more etchants; the removing of the central semiconductor-materialcontaining region forming conduits in the first stacks within the first and second memory regions; extending the conduits through the cell materials and to the channel material of the pillars; forming doped-semiconductor-material within the extended conduits; out-diffusing dopant from the doped-semiconductor- material into the channel material, the out-diffused dopant extending upwardly to at least one of the first levels; and replacing at least some of the sacrificial material of the first levels with conductive material. 23. The method of claim 22 wherein the insulative liners extend to within the protective liners and are directly against inner surfaces of the protective liners. 24. The method of claim 22 wherein the insulative liners comprise silicon dioxide. 42 25. The method of claim 22 further comprising forming a source-select-device to comprise said at least one of the first levels. 26. The method of claim 22 wherein the protective liners comprise only a single homogeneous composition. 27. The method of claim 22 wherein the protective liners comprise a laminate of two or more different compositions. 28. The method of claim 22 wherein the protective liners comprise carbon-doped silicon oxide. 29. The method of claim 22 wherein the protective liners comprise carbon-doped silicon nitride. 30. The method of claim 22 wherein the protective liners comprise SiON, where the chemical formula indicates primary constituents rather than a specific stoichiometry. 31 . The method of claim 22 wherein the protective liners consist of carbon. 43 |
INTEGRATED ASSEMBLIES
RELATED PATENT DATA
This application claims priority to and the benefit of U.S. Patent Application Serial No. 17/164,671 , filed February 1 , 2021 , the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
Methods of forming integrated assemblies (e.g., integrated memory devices). Integrated assemblies.
BACKGROUND
Memory provides data storage for electronic systems. Flash memory is one type of memory, and has numerous uses in modern computers and devices. For instance, modern personal computers may have BIOS stored on a flash memory chip. As another example, it is becoming increasingly common for computers and other devices to utilize flash memory in solid state drives to replace conventional hard drives. As yet another example, flash memory is popular in wireless electronic devices because it enables manufacturers to support new communication protocols as they become standardized, and to provide the ability to remotely upgrade the devices for enhanced features.
NAND may be a basic architecture of flash memory, and may be configured to comprise vertically-stacked memory cells.
Before describing NAND specifically, it may be helpful to more generally describe the relationship of a memory array within an integrated arrangement. FIG. 1 shows a block diagram of a prior art device 1000 which includes a memory array 1002 having a plurality of memory cells 1003 arranged in rows and columns along with access lines 1004 (e.g., wordlines to conduct signals WL0 through WLm) and first data lines 1006 (e.g., bitlines to conduct signals BLO through BLn). Access lines 1004 and first data lines 1006 may be used to transfer information to and from the memory cells 1003. A row decoder 1007 and a column decoder 1008 decode address signals A0 through AX on address lines 1009 to determine which ones of the memory cells 1003 are to be accessed. A sense amplifier circuit 1015 operates to determine the values of information read from the memory cells 1003. An I/O circuit 1017 transfers values of information between the memory array 1002 and input/output (I/O) lines 1005. Signals DQ0 through DON on the I/O lines 1005 can represent values of information read from or to be written into the memory cells 1003. Other devices can communicate with the device 1000 through the I/O lines 1005, the address lines 1009, or the control lines 1020. A memory control unit 1018 is used to control memory operations to be performed on the memory cells 1003, and utilizes signals on the control lines 1020. The device 1000 can receive supply voltage signals Vcc and Vss on a first supply line 1030 and a second supply line 1032, respectively. The device 1000 includes a select circuit 1040 and an input/output (I/O) circuit 1017. The select circuit 1040 can respond, via the I/O circuit 1017, to signals CSEL1 through CSELn to select signals on the first data lines 1006 and the second data lines 1013 that can represent the values of information to be read from or to be programmed into the memory cells 1003. The column decoder 1008 can selectively activate the CSEL1 through CSELn signals based on the A0 through AX address signals on the address lines 1009. The select circuit 1040 can select the signals on the first data lines 1006 and the second data lines 1013 to provide communication between the memory array 1002 and the I/O circuit 1017 during read and programming operations.
The memory array 1002 of FIG. 1 may be a NAND memory array, and FIG. 2 shows a schematic diagram of a three-dimensional NAND memory device 200 which may be utilized for the memory array charge-storage devices. In a first direction (Z-Z’), each string of charge-storage devices may comprise, for example, thirty-two chargestorage devices stacked over one another with each charge-storage device corresponding to one of, for example, thirty-two tiers (e.g., Tier0-Tier31 ). The charge-storage devices of a respective string may share a common channel region, such as one formed in a respective pillar of semiconductor material (e.g., polysilicon) about which the string of charge-storage devices is formed. In a second direction (X- X’), each first group of, for example, sixteen first groups of the plurality of strings may comprise, for example, eight strings sharing a plurality (e.g., thirty-two) of access lines (i.e., “global control gate (CG) lines”, also known as wordlines, WLs). Each of the access lines may couple the charge-storage devices within a tier. The chargestorage devices coupled by the same access line (and thus corresponding to the same tier) may be logically grouped into, for example, two pages, such as P0/P32, P1 /P33, P2/P34 and so on, when each charge-storage device comprises a cell capable of storing two bits of information. In a third direction (Y-Y’), each second group of, for example, eight second groups of the plurality of strings, may comprise sixteen strings coupled by a corresponding one of eight data lines. The size of a memory block may comprise 1 ,024 pages and total about 16MB (e.g., 16 WLs x 32 tiers x 2 bits = 1 ,024 pages/block, block size = 1 ,024 pages x 16KB/page = 16MB). The number of the strings, tiers, access lines, data lines, first groups, second groups and/or pages may be greater or smaller than those shown in FIG. 2.
FIG. 3 shows a cross-sectional view of a memory block 300 of the 3D NAND memory device 200 of FIG. 2 in an X-X’ direction, including fifteen strings of charge-storage devices in one of the sixteen first groups of strings described with respect to FIG. 2. The plurality of strings of the memory block 300 may be grouped into a plurality of subsets 310, 320, 330 (e.g., tile columns), such as tile columm, tile columnj and tile columnK, with each subset (e.g., tile column) comprising a “partial block” (sub-block) of the memory block 300. A global drain-side select gate (SGD) line 340 may be coupled to the SGDs of the plurality of strings. For example, the global SGD line 340 may be coupled to a plurality (e.g., three) of sub-SGD lines 342, 344, 346 with each sub-SGD line corresponding to a respective subset (e.g., tile column), via a corresponding one of a plurality (e.g., three) of sub- SGD drivers 332, 334, 336. Each of the sub-SGD drivers 332, 334, 336 may concurrently couple or cut off the SGDs of the strings of a corresponding partial block (e.g., tile column) independently of those of other partial blocks. A global source-side select gate (SGS) line 360 may be coupled to the SGSs of the plurality of strings. For example, the global SGS line 360 may be coupled to a plurality of sub-SGS lines 362, 364, 366 with each sub-SGS line corresponding to the respective subset (e.g., tile column), via a corresponding one of a plurality of sub- SGS drivers 322, 324, 326. Each of the sub-SGS drivers 322, 324, 326 may concurrently couple or cut off the SGSs of the strings of a corresponding partial block (e.g., tile column) independently of those of other partial blocks. A global access line (e.g., a global CG line) 350 may couple the charge-storage devices corresponding to the respective tier of each of the plurality of strings. Each global CG line (e.g., the global CG line 350) may be coupled to a plurality of sub-access lines (e.g., sub-CG lines) 352, 354, 356 via a corresponding one of a plurality of sub-string drivers 312, 314 and 316. Each of the sub-string drivers may concurrently couple or cut off the charge-storage devices corresponding to the respective partial block and/or tier independently of those of other partial blocks and/or other tiers. The charge-storage devices corresponding to the respective subset (e.g., partial block) and the respective tier may comprise a “partial tier” (e.g., a single “tile”) of charge-storage devices. The strings corresponding to the respective subset (e.g., partial block) may be coupled to a corresponding one of sub-sources 372, 374 and 376 (e.g., “tile source”) with each sub-source being coupled to a respective power source. The NAND memory device 200 is alternatively described with reference to a schematic illustration of FIG. 4.
The memory array 200 includes wordlines 202i to 202N, and bitlines 228i to 228M.
The memory array 200 also includes NAND strings 206i to 206M. Each NAND string includes charge-storage transistors 208i to 208N. The charge-storage transistors may use floating gate material (e.g., polysilicon) to store charge, or may use charge-trapping material (such as, for example, silicon nitride, metallic nanodots, etc.) to store charge.
The charge-storage transistors 208 are located at intersections of wordlines 202 and strings 206. The charge-storage transistors 208 represent non-volatile memory cells for storage of data. The chargestorage transistors 208 of each NAND string 206 are connected in series source-to-drain between a source-select-device (e.g., sourceside select gate, SGS) 210 and a drain-select device (e.g., drain-side select gate, SGD) 212. Each source-select-device 210 is located at an intersection of a string 206 and a source-select line 214, while each drain-select device 212 is located at an intersection of a string 206 and a drain-select line 215. The select devices 210 and 212 may be any suitable access devices, and are generically illustrated with boxes in FIG. 4.
A source of each source-select-device 210 is connected to a common source line 216. The drain of each source-select-device 210 is connected to the source of the first charge-storage transistor 208 of the corresponding NAND string 206. For example, the drain of source- select-device 210i is connected to the source of charge-storage transistor 208i of the corresponding NAND string 206i . The source- select-devices 210 are connected to source-select line 214.
The drain of each drain-select device 212 is connected to a bitline (i.e., digit line) 228 at a drain contact. For example, the drain of drain-select device 212i is connected to the bitline 228i . The source of each drain-select device 212 is connected to the drain of the last charge-storage transistor 208 of the corresponding NAND string 206. For example, the source of drain-select device 212i is connected to the drain of charge-storage transistor 208N of the corresponding NAND string 206i .
The charge-storage transistors 208 include a source 230, a drain 232, a charge-storage region 234, and a control gate 236. The charge-storage transistors 208 have their control gates 236 coupled to a wordline 202. A column of the charge-storage transistors 208 are those transistors within a NAND string 206 coupled to a given bitline 228. A row of the charge-storage transistors 208 are those transistors commonly coupled to a given wordline 202.
The vertically-stacked memory cells of three-dimensional NAND architecture may be block-erased by generating hole carriers beneath them, and then utilizing an electric field to sweep the hole carriers upwardly along the memory cells.
Gating structures of transistors may be utilized to provide gate- induced drain leakage (GIDL) which generates the holes utilized for block-erase of the memory cells. The transistors may be the sourceside select (SGS) devices described above. The channel material associated with a string of memory cells may be configured as a channel material pillar, and a region of such pillar may be gatedly coupled with an SGS device. The gatedly coupled portion of the channel material pillar is a portion that overlaps a gate of the SGS device.
It can be desired that at least some of the gatedly coupled portion of the channel material pillar be heavily doped. In some applications it can be desired that the gatedly coupled portion include both a heavily-doped lower region and a lightly-doped upper region; with both regions overlapping the gate of the SGS device. Specifically, overlap with the lightly-doped region provides a non-leaky “OFF” characteristic for the SGS device, and overlap with the heavily-doped region provides leaky GIDL characteristics for the SGS device. The terms “heavily-doped” and “lightly-doped” are utilized in relation to one another rather than relative to specific conventional meanings. Accordingly, a “heavily-doped” region is more heavily doped than an adjacent “lightly-doped” region, and may or may not comprise heavy doping in a conventional sense. Similarly, the “lightly-doped” region is less heavily doped than the adjacent “heavily-doped” region, and may or may not comprise light doping in a conventional sense. In some applications, the term “lightly-doped” refers to semiconductor material having less than or equal to about 10 18 atoms/cm 3 of dopant, and the term “heavily-doped” refers to semiconductor material having greater than or equal to about 10 22 atoms/cm 3 of dopant.
The channel material may be initially doped to the lightly-doped level, and then the heavily-doped region may be formed by out- diffusion from an underlying doped-semiconductor-material.
It is desired to develop improved methods of forming integrated memory (e.g., NAND memory). It is also desired to develop improved memory devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a prior art memory device having a memory array with memory cells.
FIG. 2 shows a schematic diagram of the prior art memory device of FIG. 1 in the form of a 3D NAND memory device. FIG. 3 shows a cross-sectional view of the prior art 3D NAND memory device of FIG. 2 in an X-X’ direction.
FIG. 4 is a schematic diagram of a prior art NAND memory array.
FIGS. 5-5B are a diagrammatic top-down view (FIG. 5) and a pair of diagrammatic cross-sectional side views (FIGS. 5A and 5B) of regions of an example integrated assembly at an example process stage of an example embodiment method for forming an example memory device. The cross-sectional side views of FIGS. 5A and 5B are along the lines A-A and B-B of FIG. 5, respectively. The top-down view of FIG. 5 is along the lines C-C of FIGS. 5A and 5B. FIGS. 6 and 6A are diagrammatic c views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 5-5B. The cross-sectional side view of FIG. 6A is along the line A-A of FIG. 6, and the cross-sectional top- down view of FIG. 6 is along the line C-C of FIG. 6A.
FIGS. 7 and 7A are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 6 and 6A. The cross- sectional side view of FIG. 7A is along the line A-A of FIG. 7, and the cross-sectional top-down view of FIG. 7 is along the line C-C of FIG. 7A.
FIGS. 8 and 8A are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 7 and 7A. The cross- sectional side view of FIG. 8A is along the line A-A of FIG. 8, and the cross-sectional top-down view of FIG. 8 is along the line C-C of FIG. 8A.
FIGS. 9-9B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 8 and 8A. The cross- sectional side views of FIGS. 9A and 9B are along the lines A-A and B-B of FIG. 9, respectively. The top-down view of FIG. 9 is along the lines C-C of FIGS. 9A and 9B.
FIGS. 10-10B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 9 and 9A. The cross- sectional side views of FIGS. 10A and 10B are along the lines A-A and B-B of FIG. 10, respectively. The top-down view of FIG. 10 is along the lines C-C of FIGS. 10A and 10B.
FIGS. 11 -11 B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 10 and 10A. The cross- sectional side views of FIGS. 11 A and 11 B are along the lines A-A and B-B of FIG. 11 , respectively. The top-down view of FIG. 11 is along the lines C-C of FIGS. 11 A and 11 B.
FIGS. 12-12B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 11 and 11 A. The cross- sectional side views of FIGS. 12A and 12B are along the lines A-A and B-B of FIG. 12, respectively. The top-down view of FIG. 12 is along the lines C-C of FIGS. 12A and 12B.
FIGS. 13-13B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 12 and 12A. The cross- sectional side views of FIGS. 13A and 13B are along the lines A-A and B-B of FIG. 13, respectively. The top-down view of FIG. 13 is along the lines C-C of FIGS. 13A and 13B.
FIGS. 14-14B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 13 and 13A. The cross- sectional side views of FIGS. 14A and 14B are along the lines A-A and B-B of FIG. 14, respectively. The top-down view of FIG. 14 is along the lines C-C of FIGS. 14A and 14B.
FIGS. 15-15B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 14 and 14A. The cross- sectional side views of FIGS. 15A and 15B are along the lines A-A and B-B of FIG. 15, respectively. The top-down view of FIG. 15 is along the lines C-C of FIGS. 15A and 15B.
FIGS. 16-16B are diagrammatic cross-sectional side views of regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 15 and 15A. The cross- sectional side views of FIGS. 16A and 16B are along the lines A-A and B-B of FIG. 16, respectively. The top-down view of FIG. 16 is along the lines C-C of FIGS. 16A and 16B. FIGS. 17A and 17B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 16-16B. The cross- sectional side views of FIGS. 17A and 17B are along the same crosssections as FIGS. 5A and 5B, respectively.
FIGS. 18A and 18B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 17A and 17B. The cross-sectional side views of FIGS. 18A and 18B are along the same cross-sections as FIGS. 5A and 5B, respectively.
FIGS. 19A and 19B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 18A and 18B. The cross-sectional side views of FIGS. 19A and 19B are along the same cross-sections as FIGS. 5A and 5B, respectively.
FIGS. 20A and 20B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 19A and 19B. The cross-sectional side views of FIGS. 20A and 20B are along the same cross-sections as FIGS. 5A and 5B, respectively.
FIGS. 21 A and 21 B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 20A and 20B. The cross-sectional side views of FIGS. 21 A and 21 B are along the same cross-sections as FIGS. 5A and 5B, respectively.
FIGS. 22A and 22B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 5-5B at an example process stage following that of FIGS. 21 A and 21 B. The cross-sectional side views of FIGS. 22A and 22B are along the same cross-sections as FIGS. 5A and 5B, respectively.
FIGS. 23A and 23B are diagrammatic cross-sectional side views of the regions of the example integrated assembly of FIGS. 22A and 22B, and show additional vertically-extended regions of such assembly besides those shown in FIGS. 22A and 22B. FIG. 23A-1 is a diagrammatic cross-sectional side view of the region of FIG. 23A shown at an alternative example process stage relative to the process stage of FIG. 23A.
FIG. 23C is a diagrammatic top-down view of the assembly of FIGS. 23A and 23B. The cross-sectional side views of FIGS. 23A and 23B are along the lines A-A and B-B of FIG. 23C, respectively. The top-down view of FIG. 23C is along the lines C-C of FIGS. 23A and 23B.
FIG. 23C-1 is a diagrammatic top-down view of the region of FIG. 23C shown at an alternative example process stage relative to that of FIG. 23C, and at the same process stage as 23A-1 . The view of FIG. 23C-1 is along the line C-C of FIG. 23A-1 , and the view of FIG. 23A-1 is along the line A-A of FIG. 23C-1 .
DETAILED DESCRI PTION OF THE ILLUSTRATED EMBODIMENTS
Some embodiments include utilization of insulative protective material to protect lower regions of conductive posts during etching of materials associated with an integrated assembly. Some embodiments include integrated assemblies having insulative protective material laterally surrounding lower regions of conductive posts. Example embodiments are described with reference to FIGS. 5-23.
FIG. 5 shows a top-down view along several example regions of an example integrated assembly 10. The illustrated regions of the assembly 10 include a pair of memory regions (memory array regions) 12a and 12b (Array-1 and Array-2), and include an intermediate region 14 between the memory regions. In some embodiments, the memory regions 12a and 12b may be referred to as first regions which are laterally displaced relative to one another (laterally offset from one another), and the intermediate region 14 may be referred to as another region (or as a second region) which is between the laterally- displaced (laterally-offset) first regions. An x/y axis system is provided relative to the top view of FIG. 5 to provide reference for a first direction and an orthogonal second direction. The first direction may be one of the x-axis and y-axis directions, and the second direction may be the other of the x-axis and y-axis directions.
FIGS. 5A and 5B show cross-sectional side-views within the intermediate region 14 and the memory region 12a, respectively. The view of FIG. 5A is along the line A-A of FIG. 5, and the view of FIG. 5B is along the line B-B of FIG. 5. The view of FIG. 5 is along the lines C-C of FIGS. 5A and 5B. The views of FIGS. 5A and 5B diagrammatically illustrate example structures represented in the top- down view of FIG. 5, but are not provided to the same scale as FIG. 5.
FIGS. 5A and 5B show an example configuration in which an insulative material 50 forms a supporting structure for a stack 52.
The insulative material 50 may comprise any suitable composition(s), and in some embodiments may comprise, consist essentially of, or consist of silicon dioxide.
In the illustrated embodiment, conductive structures 54 are within the insulative material 50. The conductive structures 54 may comprise any suitable conductive material; such as, for example, one or more of various metals (e.g., titanium, tungsten, cobalt, nickel, platinum, ruthenium, etc.), metal-containing compositions (e.g., metal silicide, metal nitride, metal carbide, etc.), and/or conductively-doped semiconductor materials (e.g., conductively-doped silicon, conductively-doped germanium, etc.).
One or more of the conductive structures 54 may be coupled with logic circuitry (e.g., CMOS) provided beneath the insulative material 50. FIG. 5A shows the logic circuitry including components 56a and 56b, which may correspond to, for example, control circuitry and/or sensing circuitry (e.g., sense-amplifier-circuitry, driver circuitry, etc.). FIG. 5B shows the logic circuitry configured to include a component 56c (e.g., control circuitry) coupled with a source structure comprising the stack 52.
The logic circuitry 56 may be supported by a semiconductor material (not shown). Such semiconductor material may, for example, comprise, consist essentially of, or consist of monocrystalline silicon (Si). The semiconductor material may be referred to as a semiconductor base, or as a semiconductor substrate. The term "semiconductor substrate" means any construction comprising semiconductive material, including, but not limited to, bulk semiconductive materials such as a semiconductive wafer (either alone or in assemblies comprising other materials), and semiconductive material layers (either alone or in assemblies comprising other materials). The term "substrate" refers to any supporting structure, including, but not limited to, the semiconductor substrates described above. The configurations described herein may be referred to as integrated configurations supported by a semiconductor substrate, and accordingly may be considered to be integrated assemblies.
The stack 52 may be referred to as a first stack, and may be considered to extend across the memory regions (12a and 12b) and the intermediate region (14) of FIG. 5. The stack 52 includes an electrically conductive material 58, and includes regions 60 and 62 over the conductive material 58. The regions 60 may be referred to as semiconductor-material-containing regions.
The conductive material 58 may be a metal-containing material, and in some embodiments may comprise, consist essentially of, or consist of one or more of tungsten, tungsten silicide, etc.
The conductive material 58 is configured as islands 40 in the intermediate region 14, as shown in FIG. 5A. Such islands are laterally spaced from one another by insulative material 42. The insulative material 42 may comprise any suitable composition(s), and in some embodiments may comprise, consist essentially of, or consist of silicon dioxide. The insulative material 42 may or may not be a same composition as the insulative material 50.
In the illustrated embodiment, there are three of the regions 60, and such regions are labeled as 60a, 60b and 60c. The regions 60a and 60c include semiconductor material 64. Such semiconductor material may comprise conductively-doped semiconductor material, such as, for example, conductively-doped silicon. In some embodiments, the silicon may be n-type doped, and accordingly may be doped with one or both of phosphorus and arsenic. The conductively-doped silicon of regions 60a and 60c may be doped to a concentration of at least about 10 22 atoms/cm 3 with one or more suitable conductivity-enhancing dopant(s). The semiconductor material within the region 60a may be the same as that within the region 60c, as shown, or may be different than that within the region 60c.
The central region 60b includes a material 34. The material 34 may comprise undoped semiconductor material, such as, for example, undoped silicon. The term “undoped” doesn’t necessarily mean that there is absolutely no dopant present within the semiconductor material, but rather means that any dopant within such semiconductor material is present to an amount generally understood to be insignificant. For instance, undoped silicon may be understood to comprise a dopant concentration of less than about 10 16 atoms/cm 3 , less than aboutI O 15 atoms/cm 3 , etc., depending on the context. In some embodiments, the material 34 may comprise, consist essentially of, or consist of silicon. In some embodiments, the material 34 is a sacrificial material (as discussed in more detail relative to processing described below with reference to FIG. 7B), and accordingly the material 34 may comprise any suitable sacrificial material including, but not limited to, undoped semiconductor material (e.g., undoped silicon).
The regions 60a-c may be considered to be vertically-stacked one atop another, with the region 60b being a central semiconductormaterial-containing region (in some embodiments), and being vertically between the regions 60a and 60c.
Intervening regions 62 alternate with the regions 60 within the stack 52. The regions 62 comprise material 66. The material 66 may be insulative, conductive, etc. In some embodiments, the material 66 may be insulative and may comprise, consist essentially of, or consist of one or more of silicon dioxide, aluminum oxide, hafnium oxide, silicon nitride, silicon oxynitride, etc. The regions 62a and 62b may comprise the same composition as one another (as shown), or may comprise different compositions relative to one another. One or both of the regions 62 may comprise a homogeneous composition (as shown) or may comprise a laminate of two or more different compositions.
Although the stack 52 is shown comprising three of the regions 60 (which may be semiconductor-material-containing regions) and two of the intervening regions 62, it is to be understood that the stack may comprise any suitable number of the regions 60 and 62. In some embodiments, the stack 52 may comprise at least three of the regions 60, and at least two of the intervening regions 62.
The regions 60 may be formed to any suitable thicknesses, and in some embodiments may be formed to thicknesses within a range of from about 100 nanometers (nm) to about 300 nm. The regions 62 may be formed to any suitable thicknesses, and in some embodiments may be formed to thicknesses within a range of from about 5 nm to about 20 nm.
Openings 80 are formed to extend through the stack 52 within the intermediate region 14. The openings 80 extend to upper surfaces of the conductive islands 40. The openings 80 are shown to have circular shapes in the top-down view of FIG. 5. In other embodiments, the openings may have other suitable closed shapes in such top-down view, and may be, for example, elliptical, square, rectangular, polygonal, etc. In some embodiments, the openings 80 may be referred to as first openings. The openings 80 have lateral sidewalls 81 . The openings 80 each have a width W along the cross-section of FIG. 5A. Such width may be any suitable width, and in some embodiments may be within a range of from about 5 nm to about 10 micrometers (microns). The integrated assembly of FIGS. 5-5A may be considered to correspond to a construction 77.
Referring to FIGS. 6 and 6A, a first liner material 30 is formed over a surface of the stack 52 and within the openings 80. In some embodiments, the liner material 30 may be referred to as a protective material in that it may be resistant to subsequent etching conditions (such etching conditions are described below with reference to FIGS. 18 and 19). The liner material 30 may be an insulative material. The material 30 may comprise any suitable composition(s). In some embodiments, the material 30 may comprise one or more of doped silicon oxide, doped silicon nitride, silicon oxynitride and carbon. For instance, the material 30 may comprise, consist essentially of, or consist of carbon- doped silicon oxide (e.g. , silicon dioxide); with the carbon concentration being within a range of from about 10 15 atoms/cm 3 to about 10 25 atoms/cm 3 . As another example, the material 30 may comprise, consist essentially of, or consist of carbon-doped silicon nitride; with the carbon concentration being within a range of from about 10 15 atoms/cm 3 to about 10 25 atoms/cm 3 . As another example, the material 30 may comprise, consist essentially of, or consist of SiON, where the chemical formula indicates primary constituents rather than a specific stoichiometry. The SiON may be referred to as silicon oxynitride in some embodiments. The Si and O may be present to concentrations within a range of from about 20 atomic percent (at%) to about 70 at%, and the nitrogen may be present to a concentration within a range of from about 0.01 at% to about 35 at%, within a range of from about 10 15 atoms/cm 3 to about 10 25 atoms/cm 3 , etc. As another example, the material 30 may comprise, consist essentially of, or consist of carbon. The carbon may be in any suitable form, and in some embodiments may be entirely in an amorphous phase, or at least substantially entirely in an amorphous phase, where the term “substantially entirely in an amorphous phase” means entirely in an amorphous phase to within reasonable tolerances of fabrication and measurement.
The liner material 30 may have any suitable thickness, and in some embodiments may have a thickness within a range of from about 5 angstroms (A) to about one-third of the width of the openings 80 along the cross-section of FIG. 5A.
The liner material 30 lines the sidewalls of the openings 80, and accordingly narrows the openings 80.
Referring to FIGS. 7 and 7A, sacrificial material 83 is formed over the liner material 30 and within the narrowed openings 80. The sacrificial material 83 may comprise any suitable composition(s), and such composition(s) may be conductive, insulative, semiconductive, etc. For instance, the material 83 may be conductive (as shown), and may be a metal-containing material. In some example embodiments, the material 83 may comprise, consist essentially of, or consist of tungsten.
Referring to FIGS. 8 and 8A, a planarized surface 61 is formed to extend across an upper surface of the stack 52 and across the materials 30 and 83 within the openings 80. The planarized surface 61 may formed with any suitable processing, including, for example, chemical-mechanical polishing (CMP).
The forming of the planarized surface 61 removes excess sacrificial material 83 from over the stack 52, and forms the remaining material 83 into sacrificial plugs 85.
Referring to FIGS. 9-9B, a second stack 68 is formed over the first stack 52. The second stack 68 has alternating first and second levels 70 and 72. The first levels 70 comprise a material 74, and the second levels 72 comprise a material 76. The materials 74 and 76 may comprise any suitable compositions. In some embodiments, the material 74 may comprise, consist essentially of, or consist of silicon nitride; and the material 76 may comprise, consist essentially of, or consist of silicon dioxide. The material 74 may be referred to as a sacrificial material (or as a second sacrificial material to distinguish it from the first sacrificial material 83), and the material 76 may be referred to as an insulative material. The stack 68 may comprise any suitable number of the levels 70 and 72, and in some embodiments may comprise many more of such levels than are illustrated in FIGS. 9A and 9B.
Referring to FIGS. 10-10B, cell-material-pillars 16 are formed within the memory regions 12a and 12b. The pillars 16 may be substantially identical to one another, with the term “substantially identical” meaning identical to within reasonable tolerances of fabrication and measurement. The pillars 16 may be provided in a tightly-packed arrangement within each of the memory regions 12a and 12b, such as, for example, a hexagonal close packed (HOP) arrangement. There may be hundreds, thousands, millions, hundreds of thousands, etc., of the pillars 16 arranged within each of the memory regions 12a and 12b.
Each of the pillars 16 comprises an outer region 18 containing memory cell materials, a channel material 20 adjacent the outer region 18, and an insulative material 22 surrounded by the channel material 20.
The cell materials within the region 18 may comprise tunneling material, charge-storage material and charge-blocking material. The tunneling material (also referred to as gate dielectric material) may comprise any suitable composition(s); and in some embodiments may comprise one or more of silicon dioxide, aluminum oxide, hafnium oxide, zirconium oxide, etc. The charge-storage material may comprise any suitable composition(s); and in some embodiments may comprise floating gate material (e.g., polysilicon) or charge-trapping material (e.g., one or more of silicon nitride, silicon oxynitride, conductive nanodots, etc.). The charge-blocking material may comprise any suitable composition(s); and in some embodiments may comprise one or more of silicon dioxide, aluminum oxide, hafnium oxide, zirconium oxide, etc. The channel material 20 comprises semiconductor material. The semiconductor material may comprise any suitable composition(s), and in some embodiments may comprise, consist essentially of, or consist of one or more of silicon, germanium, lll/V semiconductor material (e.g. , gallium phosphide), semiconductor oxide, etc. ; with the term lll/V semiconductor material referring to semiconductor materials comprising elements selected from groups III and V of the periodic table (with groups III and V being old nomenclature, and now being referred to as groups 13 and 15). In some embodiments, the semiconductor material may comprise, consist essentially of, or consist of appropriately-doped silicon.
The channel material 20 may be considered to be configured as channel-material-pillars 24. In the illustrated embodiment, the channel-material-pillars 24 are configured as annular rings in the top- down view of FIG. 10, with such annular rings surrounding the insulative material 22. Such configuration of the channel-material- pillars may be considered to correspond to a “hollow” channel configuration, with the insulative material 22 being provided within the hollows of the channel-material-pillars. In other embodiments, the channel material 22 may be configured as solid pillars. In some embodiments, the channel-material-pillars within the memory region 12a may be referred to as first channel-material-pillars, and the channel-material-pillars within the memory region 12b may be referred to as second channel-material pillars. The channel-material-pillars may be arranged within the first and second memory regions 12a and 12b in any suitable configurations. In some embodiments they may be arranged in tightly-packed configurations, such as, for example, hexagonal-close-packed (HOP) configurations.
The insulative material 22 may comprise any suitable composition(s), and in some embodiments may comprise, consist essentially of, or consist of silicon dioxide.
The cell-material-pillars 16 are formed to extend through the first stack 68 and partially into the second stack 52, as shown in FIG 10B. In the shown embodiment, the cell-material-pillars 16 extend into the lower region 60a of the stack 52, but do not extend to the conductive material 58. The cell-material-pillars 16 comprise the cell materials 18, the channel-material-pillars 24, and the dielectric material 22. In some embodiments, the segments of the stack 52 within the memory regions 12a and 12b may be considered to correspond to a source structure analogous to the source structures described above with reference to the prior art of FIGS. 1 -4.
Referring to FIGS. 11 -11 B, openings 78 are formed to extend through the second stack 68 to the sacrificial plugs 85. The openings 78 may be referred to as second openings to distinguish them from the first openings 80 of FIGS. 5 and 5A.
Referring to FIGS. 12-12B, the sacrificial plugs 85 (FIGS. 11 and 11 A) are removed to extend the second openings into the first stack 52.
Referring to FIGS. 13-13B, liner material 37 is formed over the second stack 68 and within the openings 78. The liner material 37 lines sidewalls of the openings 78 and accordingly narrows the openings. The liner material 37 may be an insulative material, and in some embodiments may comprise, consist essentially of, or consist of silicon dioxide. The liner material 37 may have any suitable thickness, and in some embodiments may have a thickness within a range of from about 5A to about 200 nm. In the illustrated embodiment, the liner material 37 is directly against the protective material 30 within bottom regions of the openings 78.
Referring to FIGS. 14-14B, the materials 37 and 30 are subjected to anisotropic etching to remove the material 37 from over the stack 68, and to extend the openings 78 to upper surfaces of the conductive islands 40. In some embodiments, the insulative protective material 30 of FIGS. 14 and 14A may be considered to be configured as first insulative rings (or alternatively, insulative liners) 31 along the lateral sidewalls 81 of the openings 80 (with the openings 80 being described above with reference to FIGS. 5 and 5A). In some embodiments, the insulative material 37 may be considered to be configured as second insulative rings (or insulative liners) 33 which extend the full vertical length of the openings 78, and which are nested within the first rings 31 along lower regions of the openings 78. The second rings 33 are directly against inner surfaces of the first rings 31 in the shown embodiment.
The openings 78 may be considered to be lined with insulative liners corresponding to the annular rings 31 and 33 at the process step of FIG. 14 and 14A, and thus may be referred to as lined openings (or in some embodiments as lined second openings).
Referring to FIGS. 15-15B, conductive material 28 is formed within the lined openings 78 (FIGS. 14 and 14A), and is patterned into conductive posts 26 within the intermediate region 14. Such patterning may comprise forming the material 28 to fill the openings 78 and to extend across the upper surface of the stack 68, and then removing excess material 28 from over the upper surface of the stack with a planarization process (e.g., CMP). The posts 26 may be arranged in any suitable configuration across the intermediate region 14, and may or may not be the same size and composition as one another.
The conductive material 28 may comprise any suitable electrically conductive composition(s); such as, for example, one or more of various metals (e.g., titanium, tungsten, cobalt, nickel, platinum, ruthenium, etc.), metal-containing compositions (e.g., metal silicide, metal nitride, metal carbide, etc.), and/or conductively-doped semiconductor materials (e.g., conductively-doped silicon, conductively-doped germanium, etc.). In some embodiments, the conductive material 28 may comprise one or more of tungsten, titanium nitride and tungsten nitride. For instance, the conductive material 28 may comprise a conductive liner comprising one or both of titanium nitride and tungsten nitride along the insulative liner material 37, and may comprise a tungsten fill laterally surrounded by the conductive liner. In the illustrated embodiment, the protective material 30 (i.e., the first liners 31 , or first annular rings) laterally surrounds lower regions 27 of the posts 26 and is not along upper regions 29 of the posts. In contrast the liner material 37 (i.e., the second liners 33 or second annular rings) is along the lower and upper regions of the conductive posts 26 and is directly adjacent to the conductive material 28 of such posts.
The protective material 30 and liner material 37 are each illustrated to comprise only a single homogenous composition in the drawings of FIGS. 15 and 15A. In other embodiments, one or both of such materials may comprise a laminate of two or more different compositions.
In some embodiments, the conductive posts 26 may be “live”, and accordingly may be utilized as electrical interconnects. Alternatively, the posts may be “dummy”, and may be utilized simply for providing structural support.
There may be hundreds, thousands, millions, etc., of the conductive posts 26 provided within the intermediate region 14.
The intermediate region 14 may comprise numerous regions associated with integrated memory, including, for example, staircase regions, crest regions, bridging regions, etc. If the conductive posts 26 are live posts, such may be utilized for interconnecting components associated with the memory regions 12a and 12b to circuitry beneath the illustrated region of the integrated assembly 10. For instance, the conductive posts may be utilized for connecting bitlines to sensing circuitry (e.g., sense-amplifier-circuitry), for connecting SGD devices to control circuitry, etc.
The illustrated posts 26 extend through the first stack 68, through the regions 60 and 62 of the second stack 52, and to the conductive material 58, as shown in FIG. 15A. In the shown embodiment, the conductive posts 26 are electrically coupled with the conductive islands 40 comprising the conductive material 58. The conductive posts 26 may be coupled to the CMOS circuitry 56 in embodiments in which the conductive posts 26 are “live” posts. Alternatively, at least some of the conductive posts 26 may not be coupled to the CMOS circuitry in embodiments in which at least some of the conductive posts are “dummy” configurations provided for structural support rather than for electrical connections.
In the shown embodiment, each of the islands 40 supports one of the conductive posts 26. In other embodiments, at least one of the islands 40 may support two or more of the conductive posts.
The conductive posts 26 of FIGS. 15 and 15A may be referred to as “protected conductive posts” in that lower regions of such posts are protected by the protective material 30.
Referring to FIGS. 16-16B, a slit-opening 82 is formed to extend across the memory regions 12a and 12b, and across the intermediate region 14. The slit opening is shown in dashed-line (phantom) view in FIG. 16 to indicate that the slit-opening is above the illustrated crosssection of FIG. 16.
The slit-opening 82 passes through the first stack 68 and into the second stack 52. In the illustrated embodiment, the slit-opening stops on the material 34. In other embodiments, the slit-opening may extend into the material 34.
In the shown embodiment, the slit-opening has sidewall surfaces which are substantially vertically straight; with the term “substantially vertically straight” meaning vertically straight to within reasonable tolerances of fabrication and measurement. In other embodiments the sidewall surfaces of the slit-opening may be tapered.
Protective material 84 is formed within the slit-opening 82, and along the sidewall surfaces of the slit-opening. The protective material 84 may comprise any suitable composition(s). In some embodiments, the protective material 84 may comprise, consist essentially of, or consist of silicon; and specifically may comprise silicon which is effectively undoped (e.g., comprising an intrinsic dopant concentration, and in some embodiments comprising a dopant concentration of less than or equal to about 10 16 atoms/cm 3 ). In some embodiments, the protective material 84 may comprise one or more of metal (e.g., tungsten, titanium, etc.), metal-containing material (e.g., metal silicide, metal nitride, metal carbide, metal boride, etc.) and semiconductor material (e.g., silicon, germanium, etc.).
Referring to FIGS. 17A and 17B, one or more etches are utilized to punch through the protective material 84 at the bottom of the slitopening 82 to expose the central semiconductor-material-containing region 60b of the first stack 52. The slit-opening 82 extends across the memory regions and the intermediate region of FIG. 16 (the regions 12a, 12b and 14). Accordingly, the removal of the protective material 84 from the bottom of the slit-opening 82 exposes the material 34 within the memory regions (e.g., the memory region 12a of FIG 17B) and within the intermediate region 14 (FIG. 17A).
Referring to FIGS. 18A and 18B, the sacrificial material 34 of the central region 60b is removed to form conduits 86 within the regions 12a, 12b and 14 (with regions 12a and 14 being shown in FIGS 18B and 18A).
The conduits 86 may be formed with any suitable processing, and in some embodiments may be formed utilizing one or more etchants containing hydrofluoric acid. In the shown embodiment, the intervening regions 62a and 62b remain after formation of the conduits 86. In other embodiments, such intervening regions may be removed during formation of the conduits, depending on the composition(s) of the intervening regions and of the etchant(s) utilized to remove the material 34.
FIG. 18A shows that the protective material 30 is resistant to the etchants utilized to form the conduits 86. In some embodiments, the material 34 exposed within the slit 82 may be considered to be selectively removed relative to the protective material 30. For purposes of interpreting this disclosure and the claims that follow, a first material is considered to be selectively removed relative to a second material if the first material is removed faster than the second material; which may include, but which is not limited to, conditions which are 100% selective for the first material relative to the second material.
Referring to FIG. 19B, the conduits 86 are extended through the cell materials 18 to expose sidewall surfaces of the semiconductor material (channel material) 20. FIG. 19A shows that no substantial change occurs within the intermediate region 14 during the extension of the conduits 86 through the cell materials 18. In other words, the protective material 30 is resistant to the etching utilized to extend the conduits 86 through the cell materials 18.
Referring to FIGS. 20A and 20B, conductively-doped- semiconductor-material 88 is formed within the conduits 86 (FIGS. 19A and 19B). The semiconductor material 88 may comprise any suitable composition(s); and in some embodiments may comprise, consist essentially of, or consist of one or more of silicon, germanium, lll/V semiconductor material (e.g., gallium phosphide), semiconductor oxide, etc. In some embodiments, the semiconductor material 88 may comprise silicon which is heavily doped (e.g., doped to a concentration of at least about 10 22 atoms/cm 3 ) with n-type dopant (e.g., phosphorus, arsenic, etc.). The conductive material 88 may be considered to be configured as a source-structure-component 90 which is coupled with lower regions of the channel-material-pillars 24. In some embodiments, the materials within the first stack 52 of FIG. 20B may all be considered to be part of a conductive source structure 43. The regions 62a and 62b may be removed during the formation of the conduits 86 of FIGS. 18A and 18B (as discussed above with reference to FIGS. 18A and 18B) so that such regions are not part of the source structure 43. In some embodiments, the regions 62a and 62b may be either conductive so that they do not adversely influence electrical conduction along the source structure 43, or may be insulative and kept thin enough so that they do not problematically influence electrical conduction along the source structure 43. The material 88 becomes the central region 60b of the stack 52 within the memory regions 12a and 12b (with the region 12a being shown in FIG. 20B)
The doped-semiconductor-material 88 directly contacts the channel material 20 of the channel-material-pillars 24 in the shown embodiment.
Referring to FIGS. 21 A and 21 B, the materials 84 and 88 are removed from within the opening (slit) 82 with one or more suitable etches. The materials may be removed with any suitable etchant(s). The slit-opening 82 may be punched to any suitable depth within the source structure 43.
Dopant is out-diffused from the conductively-doped- semiconductor-material 88 into the semiconductor material (channel material) 20 to form heavily-doped regions 92 within lower portions of the channel-material-pillars 24. Lines 93 are utilized to indicate approximate upper boundaries of the dopant within the heavily-doped regions 92.
The out-diffusion from the doped material 88 into the semiconductor material 20 may be accomplished with any suitable processing, including, for example, suitable thermal processing (e.g., thermal processing at a temperature exceeding about 300 °C for a duration of at least about two minutes).
The sacrificial material 74 (FIGS. 20A and 20B) of the first levels 70 is removed and replaced with conductive material 94. Although the conductive material 94 is shown to entirely fill the first levels 70, in other embodiments at least some of the material provided within the first levels 70 may be insulative material (e.g., dielectricbarrier material).
The conductive material 94 may comprise any suitable composition(s); and in some embodiments may comprise a tungsten core at least partially surrounded by titanium nitride. The dielectricbarrier material may comprise any suitable composition(s); and in some embodiments may comprise one or more of aluminum oxide, hafnium oxide, zirconium oxide, etc.
The first levels 70 of FIGS. 21 A and 21 B are conductive levels, and the stack 68 may be considered to comprise alternating insulative levels (intervening levels) 72 and conductive levels 70.
In the illustrated embodiment, the conductive material 94 of the conductive levels 70 is spaced from the conductive material 28 of the posts 26 by the insulative liner material 37.
Referring to FIGS. 22A and 22B, panel-material 96 is formed within the slit-opening 82. The panel-material 96 may comprise any suitable composition(s); and in some embodiments may comprise, consist essentially of, or consist of silicon dioxide. Although the panelmaterial 96 is shown to be a single homogeneous composition, in other embodiments, the panel-material may comprise a laminate of two or more different compositions.
The panel-material 96 forms a panel 98 extending across the memory regions (e.g., 12a of FIG. 22B) and the intermediate region (the region 14 of FIG. 22A).
The assembly 10 of FIG. 22B may be considered to be a memory device comprising memory cells 100 and select devices (SGS devices) 102. A lowermost of the conductive levels 70 is labeled 70a, and the doped region 92 extends to the conductive level 70a. The conductive level 70a comprises the SGS devices 102. In the shown embodiment, the dopant extends partially across the level 70a to achieve the desired balance between non-leaky OFF characteristics and leaky GIDL characteristics for the SGS devices.
Although only one of the conductive levels is shown incorporated into the SGS devices, in other embodiments multiple conductive levels may be incorporated into the SGS devices. The conductive levels may be electrically coupled with one another (ganged together) to be incorporated into long-channel SGS devices. If multiple of the conductive levels are incorporated into the SGS devices, the out-diffused dopant may extend upwardly across two or more of the conductive levels 70 which are incorporated into the SGS devices.
The memory cells 100 (e.g., NAND memory cells) are vertically- stacked one atop another. Each of the memory cells comprises a region of the semiconductor material (channel material) 20, and comprises regions (control gate regions) of the conductive levels 70. The regions of the conductive levels 70 which are not comprised by the memory cells 100 may be considered to be wordline regions (routing regions) which couple the control gate regions with driver circuitry and/or with other suitable circuitry. The memory cells 100 comprise the cell materials (e.g., the tunneling material, chargestorage material and charge-blocking material) within the regions 18.
In some embodiments, the conductive levels 70 associated with the memory cells 100 may be referred to as wordline/control gate levels (or memory cell levels), in that they include wordlines and control gates associated with vertically-stacked memory cells of NAND strings. The NAND strings may comprise any suitable number of memory cell levels. For instance, the NAND strings may have 8 memory cell levels, 16 memory cell levels, 32 memory cell levels, 64 memory cell levels, 512 memory cell levels, 1024 memory cell levels, etc.
The source structure 43 may be analogous to the source structures 216 described in the “Background” section. The source structure is shown to be coupled with control circuitry (e.g., CMOS) 56c, as shown. The control circuitry may be under the source structure (as shown), or may be in any other suitable location. The source structure may be coupled with the control circuitry 56c at any suitable process stage.
In some embodiments, the channel-material-pillars 24 may be considered to be representative of a large number of substantially identical channel-material-pillars extending across the memory region 12a of FIG. 22B, with the term “substantially identical” meaning identical to within reasonable tolerances of fabrication and measurement. The panel 98 may divide the pillars between a first block region 104 and a second block region 106. Accordingly, the memory cells 100 on one side of the panel 98 may be considered to be within the first block region 104, and the memory cells 100 on the other side of the panel 98 may be considered to be within the second block region 106. The block regions 104 and 106 may be analogous to the memory blocks (or memory sub-blocks) described above in the “Background” section of this disclosure.
FIGS. 23A and 23B show the configuration of FIGS. 22A and 22B, and show various structures (e.g., the panel 98, the conductive posts 26, and the cell-material-pillars 16) vertically-extended and coupled with additional circuit elements. The stacks 68 may be vertically-extended to extend along substantial portions of the structures 98, 26 and 16.
The cell-material-pillars 16 of FIG. 23B extend upwardly to bitlines 108. SGD devices 110 are diagrammatically illustrated as being adjacent to the upper regions of the pillars 16, and to be beneath the bitlines 108.
The bitlines 108 may extend in and out of the page relative to the cross-sectional view of FIG. 23B.
The pillars 16, bitlines 108, SGD devices 110, SGS devices 102 and memory cells 100 may be together considered to form NAND-type configurations analogous to those described above with reference to FIGS. 1 -4.
The SGD devices 110 are indicated to be coupled to the conductive posts 26 in the view of FIG. 23B, and the conductive posts 26 are indicated to be coupled with the SGD devices 110 in the view of FIG. 23A. Accordingly, in some embodiments the SGD devices 110 associated with the memory region 12a may be coupled to the logic circuitry (e.g., 56a and 56b) through the conductive posts 26 associated with the intermediate region 14.
The SGD devices 110 are examples of components that may be associated with the cell-material-pillars 16 and coupled with logic circuitry through the conductive posts 26. In other embodiments, other components may be coupled to logic circuitry through one or more of the conductive posts 26, either in addition to, or alternatively to, the SGD devices 110. For instance, the bitlines may be coupled to the logic circuitry through the conductive posts 26, and in such embodiments the logic circuitry may include sensing circuitry (e.g., sense-amplifier-circuitry) coupled to the bitlines through the conductive posts 26. Generally, one or more components may be operatively proximate to the cell-material-pillars 16 (and/or the channel-material-pillars 24), and may be coupled to the logic circuitry 56 through the conductive posts 26.
FIG. 23C shows a top-down view along the section C-C of FIGS. 23A and 23B. The panel 98 extends across the memory regions 12a and 12b, as well as across the intermediate region 14. The panel 98 is laterally between the first and second memory-block-regions 104 and 106, and subdivides the first memory-block-region 104 from the second memory-block-region 106 (i.e., separates the first memory- block-region from the second memory-block-region).
In the shown embodiment, the doped-semiconductor-material 88 is directly adjacent to segments of the panel 98 within the intermediate region 14, the memory region 12a and the memory region 12b. The doped-semiconductor-material 88 within the memory regions 12a and 12b is directly adjacent to the channel-material- pillars 24, and is electrically coupled to such channel-material-pillars. In contrast, the doped-semiconductor-material 88 is not directly adjacent to the conductive posts 26, but rather the insulative protective material 30 (and the insulative liner material 37) is between the doped-semiconductor-material 88 and the conductive posts 26 so that the conductive posts are not electrically coupled with the doped- semiconductor-material 88.
The illustrated panel 98 of FIG. 23C may be one of many panels extending across the regions 12a, 12b and 14, and spacing first and second memory-block-regions from one another. Accordingly, the illustrated memory-block-regions 104 and 106 may be representative of a large number of memory-block-regions that may be formed at the process stage represented by FIG. 23C.
The protective material 30 may comprise only a single homogeneous material (as shown in the embodiment of FIGS. 23A and 23C) or may comprise a laminate of two or more different materials. For instance, FIGS. 23A-1 and 23C-1 show an example embodiment in which the protective material 30 is a laminate of two different compositions 30a and 30b, and accordingly in which the insulative rings 31 are laminates of the two different compositions. The compositions 30a and 30b may comprise any of the compositions described above as being suitable for the composition 30 (e.g., carbon-doped silicon dioxide, carbon-doped silicon nitride, amorphous carbon, silicon oxynitride, etc.). In some embodiments, the insulative material 37 may also comprise a laminate instead of being a single homogenous composition, either in addition to the material 30 being a laminate or alternatively to the material 30 being a laminate.
The assemblies and structures discussed above may be utilized within integrated circuits (with the term “integrated circuit” meaning an electronic circuit supported by a semiconductor substrate); and may be incorporated into electronic systems. Such electronic systems may be used in, for example, memory modules, device drivers, power modules, communication modems, processor modules, and application-specific modules, and may include multilayer, multichip modules. The electronic systems may be any of a broad range of systems, such as, for example, cameras, wireless devices, displays, chip sets, set top boxes, games, lighting, vehicles, clocks, televisions, cell phones, personal computers, automobiles, industrial control systems, aircraft, etc.
Unless specified otherwise, the various materials, substances, compositions, etc. described herein may be formed with any suitable methodologies, either now known or yet to be developed, including, for example, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.
The terms “dielectric” and “insulative” may be utilized to describe materials having insulative electrical properties. The terms are considered synonymous in this disclosure. The utilization of the term “dielectric” in some instances, and the term “insulative” (or “electrically insulative”) in other instances, may be to provide language variation within this disclosure to simplify antecedent basis within the claims that follow, and is not utilized to indicate any significant chemical or electrical differences.
The terms “electrically connected” and “electrically coupled” may both be utilized in this disclosure. The terms are considered synonymous. The utilization of one term in some instances and the other in other instances may be to provide language variation within this disclosure to simplify antecedent basis within the claims that follow.
The particular orientation of the various embodiments in the drawings is for illustrative purposes only, and the embodiments may be rotated relative to the shown orientations in some applications. The descriptions provided herein, and the claims that follow, pertain to any structures that have the described relationships between various features, regardless of whether the structures are in the particular orientation of the drawings, or are rotated relative to such orientation.
The cross-sectional views of the accompanying illustrations only show features within the planes of the cross-sections, and do not show materials behind the planes of the cross-sections, unless indicated otherwise, in order to simplify the drawings.
When a structure is referred to above as being “on”, “adjacent” or “against” another structure, it can be directly on the other structure or intervening structures may also be present. In contrast, when a structure is referred to as being “directly on”, “directly adjacent” or “directly against” another structure, there are no intervening structures present. The terms "directly under", "directly over", etc., do not indicate direct physical contact (unless expressly stated otherwise), but instead indicate upright alignment.
Structures (e.g., layers, materials, etc.) may be referred to as “extending vertically” to indicate that the structures generally extend upwardly from an underlying base (e.g., substrate). The vertically- extending structures may extend substantially orthogonally relative to an upper surface of the base, or not.
Some embodiments include an integrated assembly having a memory region adjacent to another region. Channel-material-pillars are arranged within the memory region, and conductive posts are arranged within said other region. A source structure is coupled to lower regions of the channel-material-pillars. A panel extends across the memory region and said other region, and separates a first memory-block-region from a second memory-block-region. Doped- semiconductor-material is directly adjacent to the panel within the memory region and the other region. The doped-semiconductor- material is at least part of the source structure within the memory region. First liners are adjacent lower regions of the conductive posts and laterally surround the lower regions of the conductive posts. The first liners are between the conductive posts and the doped- semiconductor-material. Second liners are directly adjacent to upper regions of the conductive posts and laterally surround the upper regions of the conductive posts.
Some embodiments include an integrated assembly having a first memory region, a second memory region offset from the first memory region, and an intermediate region between the first and second memory regions. First channel-material-pillars are arranged within the first memory region. Second channel-material-pillars are arranged within the second memory region. Conductive posts are arranged within the intermediate region. A panel extends across the first memory region, the intermediate region and the second memory region. The panel is laterally between a first memory-block-region and a second memory-block-region. Doped-semiconductor-material is within the first memory region, the second memory region and the intermediate region, and is directly adjacent to the panel. The doped- semiconductor-material is at least part of conductive source structures within the first and second memory regions. Insulative rings laterally surround lower regions of the conductive posts and are between the conductive posts and the doped-semiconductor-material. The doped- semiconductor-material directly contacts outer edges of the insulative rings. Insulative liners are along upper regions of the conductive posts and directly contact the upper regions of the conductive posts.
Some embodiments include a method of forming an integrated assembly. A construction is formed to include a first memory region, a second memory region laterally offset from the first memory region, and an intermediate region laterally between the first and second memory regions. The construction includes a first stack extending across the first memory region, the second memory region and the intermediate region. The first stack comprises alternating semiconductor-material-containing regions and intervening regions. There being at least three of the semiconductor-material-containing regions, with one of the semiconductor-material-containing regions being a central semiconductor-material-containing region and being vertically between two others of the semiconductor-materialcontaining regions. The construction includes conductive islands under the first stack within the intermediate region. First openings are formed to extend through the first stack within the intermediate region and to the conductive islands. Sidewall surfaces of the first openings are lined with protective liners to thereby form lined first openings. Sacrificial plugs are formed within the lined first openings. The sacrificial plugs comprise first sacrificial material. A second stack is formed over the first stack and the sacrificial plugs. The second stack extends across the first memory region, the second memory region and the intermediate region. The second stack comprises alternating first and second levels, with the first levels comprising second sacrificial material and the second levels comprising insulative material. Pillars are formed to extend through the second stacks of the first and second memory regions and at least partially into the first stacks of the first and second memory regions, the pillars including cell materials and channel material. Second openings are formed to extend through the second stack to the sacrificial plugs. The sacrificial plugs are removed. Insulative liners are formed along sidewalls of the second openings to thereby form lined second openings. Conductive posts are formed within the lined second openings. A slit-opening is formed to pass through the second stack and to the central semiconductor-material-containing region of the first stack. The slit-opening extends across the first memory region, the intermediate region and the second memory region. The central semiconductor-material-containing region is removed from within the first memory region, the intermediate region and the second memory region with one or more etchants flowed into the slit-opening. The protective liners are resistant to said one or more etchants. The removal of the central semiconductor-material-containing region forms conduits in the first stacks within the first and second memory regions. The conduits are extended through the cell materials and to the channel material of the pillars. Doped-semiconductor-material is formed within the extended conduits. Dopant is out-diffused from the doped-semiconductor-material into the channel material. The out- diffused dopant extends upwardly to at least one of the first levels. At least some of the sacrificial material of the first levels is replaced with conductive material.
In compliance with the statute, the subject matter disclosed herein has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the claims are not limited to the specific features shown and described, since the means herein disclosed comprise example embodiments. The claims are thus to be afforded full scope as literally worded, and to be appropriately interpreted in accordance with the doctrine of equivalents.