Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE USING A SELECTIVELY GROUNDED AND MOVABLE PROCESS KIT RING
Document Type and Number:
WIPO Patent Application WO/2014/159222
Kind Code:
A1
Abstract:
Embodiments of methods and apparatus for processing a substrate are provided herein. In some embodiments, a process kit for a substrate process chamber may include a ring having a body and a lip extending radially inward from the body, wherein the body has a first annular channel formed in a bottom of the body; an annular conductive shield having a lower inwardly extending ledge that terminates in an upwardly extending portion configured to interface with the first annular channel of the ring; and a conductive member electrically coupling the ring to the conductive shield when the ring is disposed on the conductive shield.

Inventors:
RASHEED, Muhammad (3894 Timberline Drive, San Jose, California, 95121, US)
SAVANDAIAH, Kirankumar (185 2nd G Main Road, Block 2nd Stage NagarabhaviBangalore, Karnataka 2, 560072, IN)
JOHANSON, William (10260 Lucky Court, Gilroy, California, 95020, US)
GE, Zhenbin (2463 Ottawa Way, San Jose, California, 95130, US)
YOSHIDOME, Goichi (1500 Park Avenue #119, Emeryville, California, 94608, US)
RITCHIE, Alan A. (323 Oakwood Place, Menlo Park, California, 94025, US)
Application Number:
US2014/022593
Publication Date:
October 02, 2014
Filing Date:
March 10, 2014
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
APPLIED MATERIALS, INC. (3050 Bowers Avenue, Santa Clara, California, 95054, US)
International Classes:
H01L21/02
Foreign References:
US20110272100A12011-11-10
US20120003836A12012-01-05
US20120103257A12012-05-03
US20130032478A12013-02-07
US20120205241A12012-08-16
Attorney, Agent or Firm:
TABOADA, Alan (Moser Taboada, 1030 Broad StreetSuite 20, Shrewsbury New Jersey, 07702, US)
Download PDF:
Claims:
Claims:

1 . A process kit for a substrate process chamber, comprising:

a ring having a body and a lip extending radially inward from the body, wherein the body has a first channel formed in a bottom of the body;

an annular conductive shield having a lower inwardly extending ledge that terminates in an upwardly extending portion configured to interface with the first channel of the ring; and

a conductive member electrically coupling the ring to the conductive shield when the ring is disposed on the conductive shield.

2. The process kit of claim 1 , further comprising a second channel formed in the bottom of the body, wherein the conductive member is at least partially disposed within the second channel, and wherein the conductive member is one of a tubular or solid ring, or a canted coil spring.

3. The process kit of claim 2, wherein the second channel is positioned radially outward from the first channel such that the conductive member contacts an inner surface of the lower inwardly extending ledge of the annular conductive shield.

4. The process kit of claim 2, wherein the lower inwardly extending ledge of the annular conductive shield comprises an inwardly extending radial lip coupled to an outer surface of the lower inwardly extending ledge, and wherein the second channel is positioned such that the conductive member contacts the inwardly extending radial lip.

5. The process kit of claim 2, wherein the second channel is disposed radially inward of the first channel such that the conductive member contacts a conductive housing of a substrate support disposed beneath the process kit, and wherein the housing is electrically coupled to the annular conductive shield.

6. The process kit of any of claims 1 to 5, wherein the lower inwardly extending ledge of the annular conductive shield comprises a plurality of gas holes to allow a flow of gas through the annular conductive shield.

7. The process kit of any of claims 1 to 5, wherein the body comprises a plurality of tabs extending downward from the bottom of the body to contact the annular conductive shield when the ring is disposed on the conductive shield.

8. The process kit of any of claims 1 to 5, wherein the lip overlaps a portion of a deposition ring disposed beneath the process kit.

9. The process kit of claim 8, wherein the lip comprises an annular ring extending downward from the lip and configured to interface with a channel formed in the deposition ring to limit a flow of plasma or process gas between the deposition ring and the ring.

10. The process kit of any of claims 1 to 5, further comprising a first grounding strap electrically coupling the annular conductive shield to a conductive housing of a substrate support disposed beneath the process kit.

1 1 . The process kit of claim 10, wherein the conductive member is a second grounding strap electrically coupling the ring to the conductive housing of the substrate support to electrically couple the ring to the annular conductive shield.

12. A method for processing a substrate, comprising:

placing a substrate atop a substrate support disposed beneath a processing volume of a process chamber having a conductive shield surrounding the processing volume and a ring selectably supportable by the conductive shield, wherein the conductive shield is grounded;

positioning the substrate support in a first position such that the substrate support is not in contact with the ring and such that a conductive member electrically coupled to the ring contacts the conductive shield to electrically couple the ring to the conductive shield so that the ring is coupled to ground; and

performing a plasma enhanced etch process on the substrate.

13. The method of claim 12, further comprising:

positioning the substrate support in a second position such that the substrate support is in contact with the ring and such that the conductive member does not contact the conductive shield so that the ring is electrically floating; and

performing a plasma enhanced deposition process.

14. The method of any of claims 12 to 13, wherein etching the layer disposed atop the substrate comprises:

redistributing at least a portion of the layer from a bottom surface of a feature formed in the substrate to a sidewall of the feature formed in the substrate.

15. The method of any of claims 12 to 13, wherein performing the plasma enhanced deposition process comprises:

depositing a layer of material atop the substrate such that an amount of material deposited atop a bottom surface of a feature formed in the substrate is greater than an amount of material deposited atop a sidewall of the feature formed in the substrate.

Description:
METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE USING A SELECTIVELY GROUNDED AND MOVABLE PROCESS KIT RING

FIELD

[0001] Embodiments of the present invention generally relate to a semiconductor processing.

BACKGROUND

[0002] Some substrate process chambers utilize a process kit that includes a cover ring disposed above a dielectric deposition ring. The cover ring includes a central opening through which an exposed substrate is processed. The inventors have observed that the grounding condition {e.g., electrically grounded or floating) of the cover ring may influence a processing profile of the substrate proximate an edge of the substrate. For example, the cover ring may be grounded via physical contact of the ring to a grounded chamber component {e.g., a shield) during some processes to facilitate process uniformity at the edge of the substrate. However, the inventors have discovered that for processes utilizing power provided in a VHF range {e.g., greater than about 30 MHz), the existing physical contact between the ring and process chamber components is not sufficient to electrically ground the ring, resulting in an increase in electrical potential of the ring, and thus, process non- uniformities across the substrate.

[0003] Therefore, the inventors have provided improved methods and apparatus for processing substrates.

SUMMARY

[0004] Embodiments of methods and apparatus for processing a substrate are provided herein. In some embodiments, a process kit for a substrate process chamber includes: a ring having a body and a lip extending radially inward from the body, wherein the body has a first annular channel formed in a bottom of the body; an annular conductive shield having a lower inwardly extending ledge that terminates in an upwardly extending portion configured to interface with the first annular channel of the ring; and a conductive member electrically coupling the ring to the conductive shield when the ring is disposed on the conductive shield. [0005] In some embodiments, process chamber includes: a substrate support disposed within an inner volume of the process chamber, the substrate support having a deposition ring disposed atop the substrate support and a conductive housing disposed about the substrate support; a process kit disposed about a peripheral edge of the substrate support, wherein at least a portion of the process kit is disposed above a substrate supporting surface of the substrate support, and wherein the process kit includes: a ring having a body and a lip extending radially inward from the body, the lip partially overlapping a portion of the deposition ring, wherein the body has a first annular channel formed in a bottom of the body; an annular conductive shield having a lower inwardly extending ledge that terminates in an upwardly extending portion configured to interface with the first channel of the ring; and a conductive member electrically coupling the ring to the conductive shield when the ring is disposed on the conductive shield.

[0006] In some embodiments, a method for processing a substrate includes: placing a substrate atop a substrate support disposed beneath a processing volume of a process chamber having a conductive shield surrounding the processing volume and a ring selectably supportable by the conductive shield, wherein the conductive shield is grounded; positioning the substrate support in a first position such that the substrate support is not in contact with the ring and such that a conductive member electrically coupled to the ring contacts the conductive shield to electrically couple the ring to the conductive shield so that the ring is coupled to ground; and performing a plasma enhanced etch process on the substrate.

[0007] Other and further embodiments of the present invention are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments of the present invention, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the invention depicted in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. [0009] Figure 1 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0010] Figure 2 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0011] Figure 3 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0012] Figure 4 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0013] Figure 5 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0014] Figure 6 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0015] Figure 7 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0016] Figure 8 depicts a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0017] Figures 9A-B depict a portion of a process kit for a substrate process chamber in accordance with some embodiments of the present invention.

[0018] Figure 10 depicts a method for processing a substrate in accordance with some embodiments of the present invention.

[0019] Figures 1 1A-C depict side views of a portion of a substrate during various stages of a method for processing a substrate in accordance with some embodiments of the present invention.

[0020] Figure 12 depicts a process chamber suitable for use with a process kit in accordance with some embodiments of the present invention.

[0021] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

[0022] Embodiments of selectively groundable cover rings and methods for processing a substrate are provided herein. In at least some embodiments, the inventive cover ring and methods of use may facilitate a selective grounding of the cover ring to accommodate for the requirements of a desired process. In addition, when grounded, the inventive cover ring and method may provide a more robust electrical coupling of the cover ring to conductive process chamber components as compared to conventional process kits. Moreover, embodiments of the inventive cover ring and method may provide an electrical coupling (and therefore, grounding) during processes utilizing a high frequency power source {e.g., greater than about 30 MHz) that would otherwise not be obtainable by conventional grounding techniques.

[0023] Figure 1 depicts a process kit for a substrate process chamber in accordance with some embodiments of the present invention. The process kit may be used when processing a substrate, for example, as described in method 1000 as discussed below with respect to Figure 10. In some embodiments, the process kit 104 may generally include a ring 108 {e.g., a cover ring) and a conductive member 120 to electrically couple the ring 108 to a conductive shield 122. In some embodiments, the process kit 104 and conductive shield 122 are generally disposed about a substrate support 100.

[0024] In some embodiments, the substrate support 100 may generally comprise a body 132 having a plurality of layers {e.g., three layers: first layer 158, second layer 160, and third layer 162 shown) and a substrate supporting surface 134 to support a substrate 102. The substrate 102 may be any type of substrate suitable for the fabrication of a semiconductor device. For example, the substrate 102 may be a doped or un-doped silicon substrate, a l l l-V compound substrate, a silicon germanium (SiGe) substrate, an epi-substrate, a silicon-on-insulator (SOI) substrate, a display substrate such as a liquid crystal display (LCD), a plasma display, an electro luminescence (EL) lamp display, a light emitting diode (LED) substrate, a solar cell array, solar panel, or the like. In some embodiments, the substrate 102 may be a semiconductor wafer, such as a 200, 300, or 450 mm semiconductor wafer, or the like. In some embodiments, the substrate 102 may comprise one or more layers (not shown), for example, such as dielectric layers, oxide layers, nitride layers, or the like. In addition, in some embodiments the substrate 102 may comprise one or more features formed in the substrate 102, for example, such as a trench, via, dual damascene structure, or the like. In some embodiments, the one or more features may be high aspect ratio features having, for example, a height to width aspect ratio of at least about 4:1 .

[0025] In some embodiments, two or more of the plurality of layers may be coupled together via a fastener 140. In some embodiments, a deposition ring 106 may be disposed atop the body 132 and about a peripheral edge of the substrate supporting surface 134. When present, the deposition ring 106 may protect underlying portions of the substrate support 100 during processing.

[0026] In some embodiments, one or more of the plurality of layers may be configured to facilitate performing a desired process in the process chamber. For example, in some embodiments, a first layer 158 may be fabricated from a dielectric material and have an electrode embedded therein to provide chucking power to facilitate securing the substrate 102 on the substrate support surface 134 {e.g., an electrostatic chuck). The dielectric material may be any process compatible dielectric material, for example, a ceramic such as aluminum oxide (AI 2 O 3 ), silicon nitride (SiN), or the like. Additional layers {e.g., the second layer 160 and third layer 162) may include one or more conductive layers disposed below the first layer 158 configured to, for example, be part of an RF electrode, or the like which may be used to provide RF energy to the substrate support 100. Alternatively, or in combination, in some embodiments, cooling channels (not shown) may be disposed within one or more of the plurality of layers and configured to flow a coolant to control a temperature of the substrate support and/or substrate.

[0027] In some embodiments, the substrate support 100 may comprise a housing 130 disposed about the body 132 of the substrate support 100. When present, the housing 130 covers at least a portion of the substrate support 100 to protect the substrate support 100 during processing. In some embodiments, the housing 130 may comprise a first end 166 configured to rest upon a portion of substrate support 100, a second end 168 extending radially outward from the first end 166 and a center portion 170 coupling the first end 166 to the second end 168. The housing 130 may be fabricated from any process compatible conductive material suitable for use in a process chamber {e.g., the process chamber discussed below with respect to Figure 12), for example, a metal, such as aluminum, an aluminum alloy, stainless steel, titanium, or the like.

[0028] The conductive shield 122 surrounds the process kit 104 and extends upwards along the walls of the process chamber {e.g., as described below with respect to Figure 12). In some embodiments, the conductive shield 122 may be annularly shaped, having a lower inwardly extending ledge 154 that terminates in an upwardly extending portion 126. In such embodiments, the conductive shield 122 may be disposed in the process chamber such that the conductive shield 122 surrounds at least a portion of the substrate support 100, for example as shown in Figure 1 . In some embodiments, the conductive shield 122 may be grounded via, for example, an electrical coupling of a portion of the conductive shield 122 to a grounded component of the process chamber {e.g., the chamber body). The conductive shield 122 may be fabricated from any process compatible conductive material suitable for use in the process chamber, for example, a metal, such as aluminum, an aluminum alloy, stainless steel, titanium, or the like.

[0029] In some embodiments, the conductive shield 122 may be electrically coupled to the housing 130, thus grounding the housing 130 when the conductive shield 122 is coupled to a grounded portion of the process chamber, such as described above. In such embodiments, the conductive shield 122 may be electrically coupled to the housing 130 via a first grounding strap 128. The first grounding strap 128 may comprise any type of grounding strap suitable to electrically couple the conductive shield 122 to the housing 130, for example such as a strip of material, a braided material, a ring of material, or the like. The first grounding strap 128 may be fabricated from any process compatible conductive material, for example such as aluminum. In some embodiment, the conductive material may be flexible to facilitate continuous coupling of the conductive shield 122 to the housing 130 during movement of the substrate support 100. In some embodiments, one or more fasteners (one fastener 136 shown) and/or washers 142 may facilitate coupling the first grounding strap 128 to the housing 130.

[0030] The ring 108 generally comprises a body 144 and a lip 1 14 extending radially inward from the body 144. The ring 108 may be fabricated from any process compatible conductive material suitable for use in a process chamber, for example, a metal, such as aluminum, an aluminum alloy, stainless steel, titanium, or the like.

[0031] In some embodiments, the body 144 of the ring 108 may include one or more features configured to interface with components of the process chamber, such as the conductive shield 122, a substrate support 100, or the like. For example, in some embodiments, a first annular channel 1 10 may be formed in a bottom 148 of the body 144 to interface with an end (upwardly extending portion 126) of the inwardly extending ledge 154 of the conductive shield 122. Alternatively, or in combination, in some embodiments, the body 144 may have a downwardly extending ring 124 extending from the bottom 148 of the body 144 and configured to interface with an outer surface 156 of the housing 130 of the substrate support 100. When present, the above described features {e.g., the first annular channel 1 10 and/or the downwardly extending ring 124) may facilitate precise placement of the ring 108 as the ring 108 is moved during, before, or after a process is performed.

[0032] The conductive member 120 electrically couples the ring 108 to the conductive shield 122 when the ring 108 is disposed on the conductive shield 122, such as shown in Figure 1 . The inventors have observed that providing the conductive member 120 provides a more robust electrical coupling (and thus grounding of the ring 108 via the conductive shield 122) as compared to, for example, just contacting portions of the body 144 of the ring 108 to the conductive shield 122. In addition, the inventors have observed that the conductive member 120 may provide an electrical coupling during processes utilizing a high frequency power source {e.g., greater than about 30 MHz) that would otherwise not be obtainable by contacting portions of the body 144 of the ring 108 to the conductive shield 122. [0033] The conductive member 120 may have any size or shape suitable to provide the above described electrical coupling of the conductive shield 122 and the ring 108. For example, in some embodiments, the conductive member 120 may be a gasket, a tubular or solid ring, or in some embodiments, a canted coil spring. The conductive member 120 may be fabricated from any process compatible conductive materials, for example, a metal such as aluminum, an aluminum alloy, stainless steel, beryllium copper, nickel, nickel plated copper, or the like.

[0034] In some embodiments, the conductive member 120 may be at least partially disposed within a second channel 1 18 formed in the bottom 148 of the body 144. The second channel 1 18 may be disposed in any position with respect to the body 144, for example, such as disposed radially outward of the first annular channel 1 10. In such embodiments, the conductive member 120 contacts the inwardly extending ledge 154 of the conductive shield 122. Alternatively, or in combination, in some embodiments, a second conductive member 121 may be at least partially disposed in a third channel 1 19 formed in body 144 in the first annular channel 1 10. In such embodiments, the second conductive member 121 contacts the upwardly extending portion 126 of the conductive shield 122.

[0035] In some embodiments, the body 144 may comprise a plurality of tabs (two tabs 1 12, 146 shown) extending from the bottom 148 of the body 144. When present, the plurality of tabs provide an increased surface area of contact between the body 144 and the conductive shield 122 to facilitate electrically coupling the body 144 to the conductive shield 122. The plurality of tabs may be disposed in any position suitable to provide the above described contact between the body 144 and the conductive shield 122. For example in some embodiments, the plurality of tabs may be disposed adjacent to the second channel 1 18, such as shown in Figure 1 . The plurality of tabs may comprise any size and shape suitable to provide the increased contact between the body 144 and the conductive shield 122. For example, in some embodiments, each of the plurality of tabs may be rectangular, having a length of about 0.020 to about 0.250 inches, or in some embodiments, about 0.060 inches, a width of about 0.020 to about 0.250 inches, or in some embodiments, about 0.020 inches, and a thickness of about 0.005 to about 0.250 inches, or in some embodiments, about 0.020 inches. Although two tabs 1 12, 146 are shown, any number of tabs may be utilized to provide sufficient contact between the ring 108 and the conductive shield 122. For example, in some embodiments, three sets of two tabs may be disposed adjacent to the second channel 1 18 and symmetrically about the ring 108.

[0036] In some embodiments, the lip 1 14 may be configured to at least partially overlap with a portion of the deposition ring 106. Configuring the lip 1 14 to at least partially overlap the portion of the deposition ring 106 allows the lip 1 14 to interface with the deposition ring 106 as the deposition ring 106 is raised. In some embodiments, the lip 1 14 may have an end 152 configured to interface with a feature 150 formed in an upper surface 1 16 of the deposition ring 106.

[0037] In operation, as the deposition ring 106 is raised (via raising the substrate support 100), the deposition ring 106 interfaces with the lip 1 14 and lifts the ring 108, for example, such as shown in Figure 2. By lifting the ring 108, contact between the conductive member 120 and the ring 108 (as well as the second conductive member 121 , if included, and the upwardly extending portion 126) is broken, thereby eliminating the electrical coupling between the conductive shield 122 and the ring 108, thus causing the ring 108 to be electrically floating. As such, the ring 108 may be selectively grounded in accordance with a desired process performed in the process chamber by lifting the ring 108 and eliminating coupling between the conductive shield 122 and the ring 108 (as shown in Figure 2) or lowering the ring to electrically couple the conductive shield 122 and the ring 108 (as shown in Figure 1 ). For example, the inventors have observed that when performing an etch process the ring 108 may be grounded by lowering the substrate support 100 to allow the conductive member 120 to contact the conductive shield 122, thus electrically coupling the conductive shield 122 and the ring. Alternatively, the inventors have observed that when performing a deposition process, the ring 108 may be lifted to cause the ring 108 to be electrically floating, as described above.

[0038] Referring to Figure 3, in some embodiments, the lip 1 14 may comprise a downwardly extending protrusion 302 configured to interface with a channel 304 formed in the deposition ring 106. When present, the protrusion 302 and channel 304 provides a non-linear flow path (indicated by arrow 306) between the ring 108 and the deposition ring 106, thereby reducing or eliminating a flow of process gases and/or plasma from a processing area {e.g., an area proximate the substrate 102) to outside of the substrate support 100 (e.g., proximate the first grounding strap 128, conductive shield 122, or the like).

[0039] Although the conductive member 120 is shown in Figures 1 -3 as positioned such that the conductive member 120 contacts the inwardly extending ledge 154 of the conductive shield 122, the conductive member 120 may be disposed in any position suitable to provide an adequate electrical coupling of the ring 108 and conductive shield 122 to provide the selective grounding of the ring 108 as described above. For example, referring to Figure 4, in some embodiments, the second channel 1 18 and the conductive member 120 may be disposed radially inward of the first annular channel 1 10. In such embodiments, the conductive member 120 may contact an inwardly extending radial lip 402 disposed on an outer surface 508 of the inwardly extending ledge 154. In some embodiments, disposing the conductive member 120 radially inward of the first annular channel 1 10 and providing the inwardly extending radial lip 402 may provide a non-linear flow path (indicated by arrow 410) between the ring 108 and the deposition ring 106, thereby reducing or eliminating instances of particles that are formed from contact between the ring 108 and the conductive shield 122 from reaching the substrate 102. The flow paths in Figures 3 and 4 are bi-directional flows as indicated by 306 and 410, i.e., the gas flow may be in either direction depending on the process. For example, as indicated in Figure 4, under some conditions, such as pressurizing the processing volume (1248, Figure 12) the gas flow would be left-to-right as drawn. Under different conditions, such as during pump down of the chamber, the gas flow would be right-to-left as illustrated in Figure 4.

[0040] In some embodiments, a plurality of gas holes 404 may be formed in the conductive shield 122 to allow a flow of gas through the conductive shield 122 during processing. When present, the plurality of gas holes 404 may further reduce or eliminate instances of particles that are formed from contact between the ring 108 and the conductive shield 122 from reaching the substrate 102. The plurality of gas holes 404 may be disposed in any position about the conductive shield 122. For example, in some embodiments, the plurality of gas holes 404 may be disposed beneath the inwardly extending radial lip 402, such as shown in Figure 4. In addition, each of the plurality of gas holes 404 may comprise any dimensions suitable to allow a desired amount of gas flow through the conductive shield 122. For example, in some embodiments, each of the plurality of gas holes 404 may have a diameter of about 0.010 to about 0.25 inches, or in some embodiments, about 0.050 inches

[0041] In embodiments where the second channel 1 18 and the conductive member 120 are disposed radially inward of the first annular channel 1 10, such as shown in Figure 4, the plurality of tabs (one tab 406 shown) may be disposed in an area away from the second channel 1 18. In such embodiments, each tab 406 of the plurality of tabsjnay have a width of about 0.02 to about 0.25 inches, or in some embodiments, about 0.05 inches, a length of about 0.02 to about 0.25 inches, or in some embodiments about 0.2 inches, and a thickness of about 0.005 to about 0.25 inches, or in some embodiments, about .020 inches.

[0042] Although the conductive member 120 is shown in Figures 1 -4 as positioned between the ring 108 and conductive shield 122, the conductive member 120 may be positioned between any of the conductive components of the process chamber to facilitate grounding the ring 108. For example, in some embodiments, the conductive member 120 may be positioned such that the conductive member 120 electrically couples the ring 108 to the housing 130, such as shown in Figure 5. In such embodiments, the second channel 1 18 may be formed in a top surface 502 of the housing 130 and the conductive member 120 at least partially disposed in the second channel 1 18.

[0043] Although described above as a gasket, a tubular or solid ring, a canted coil, or the like in Figures 1 -5, the conductive member 120 may be any type of process- compatible conductive component suitable to electrically couple the ring 108 and conductive shield 122 and/or housing 130. For example, in some embodiments, the conductive member 120 may be a grounding strap, for example such as the second grounding strap 602 shown in Figure 6. In some embodiments, the second grounding strap 602 may electrically couple the ring 108 to the housing 130. In such embodiments, the ring 108 may be coupled to a ledge 604 extending radially outward from the center portion 170 of the housing 130.

[0044] By utilizing the second grounding strap 602, the ring 108 remains electrically coupled to the housing 130 (and, therefore, grounded via the electrical coupling of the conductive shield 122 to the housing 130) when lifted by the substrate support 100, thus allowing the ring 108 to be grounded regardless of the position of the ring 108. The second grounding strap 602 may be any type of grounding strap having any shape and material composition, for example such as the materials, shapes and types of grounding straps discussed above with respect to the first grounding strap 128.

[0045] In some embodiments, the second grounding strap 602 may be disposed above the first grounding strap 128 such that at least a portion of the second grounding strap 602 overlaps with at least a portion of the first grounding strap 128, such as shown in Figure 7. Alternatively, in some embodiments, the second grounding strap 602 may be offset from the first grounding strap 128, for example, such as shown in Figure 6.

[0046] As illustrated in Figures 5-7, grounding of the ring 108 is achieved through electrically conductive contact with the housing 130. Primary contact between the ring 108 and the housing 130 is provided by the conductive member 120 (Figure 5) and/or by the second grounding strap 602 (Figures 6 and 7).

[0047] Alternatively, or in combination, in some embodiments, the conductive member 120 may be disposed on an inner surface 802 of the first annular channel 1 10 such that the conductive member 120 contacts the conductive shield 122 at an inner surface 808 of the upwardly extending portion 126, such as shown in Figure 8. Alternatively, or in combination, in some embodiments, the conductive member 120 may be disposed on an inner surface 802 of the first annular channel 1 10 such that the conductive member 120 contacts the conductive shield 122 at an outer surface 810 of the upwardly extending portion 126 (second channel 804 and conductive member 806 shown in phantom).

[0048] The inventors have observed that by providing contact between the conductive member 120 and the inner surface 808 and/or the outer surface 810 of the upwardly extending portion 126, the contact (and thus the electrical coupling) between the ring 108 and the conductive shield 122 will be maintained during movement of the ring 108 until the conductive member 120 is moved beyond the end of the upwardly extending portion 126 of the conductive shield 122. Thus, the height of the ring 108 may be adjusted while the ring 108 remains grounded, thereby providing more flexibility in processing.

[0049] In some embodiments, the conductive shield 122 may comprise one or more features configured to interface with the conductive member 120 to facilitate the electrical coupling of the ring 108 and the conductive shield 122, as described above. For example, in some embodiments, the conductive shield 122 may comprise a protrusion 902 extending from the inner surface 808 of the upwardly extending portion 126 and configured to interface with the conductive member 120 such as shown in Figure 9A. Alternatively, or in combination, in some embodiments, the conductive shield 122 may comprise a second conductive member 904 configured to interface with the conductive member 120, such as shown in Figure 9B. The second conductive member 904 may be partially disposed within a third channel 906. In such embodiments, the conductive member 120 may be of any type, shape, size and fabricated from any suitable materials, for example such as the type, shape, size and materials discussed above with respect to the conductive member 120.

[0050] The aforementioned apparatus may be useful for advantageously providing variable ground conditions within the process chamber when processing a substrate. For example, Figure 10 depicts an illustrative method 1000 of processing a substrate in accordance with embodiments of the present invention. The method 1000 generally begins at 1002 where a substrate 102 is placed atop a substrate support 100 of a process chamber, such as the substrate support shown in Figure 1 . Next at 1004, the substrate support 100 is positioned in a first position such that the substrate support 100 is not in contact with the ring 108 and such that the ring 108 is electrically coupled to the conductive shield 122, such as shown in Figure 1 . By positioning the substrate support 100 in the first position, the ring 108 is grounded, thus providing a grounded plane (a plane parallel to a top surface of the ring 108) disposed above the substrate 102. [0051] The inventors have observed that by providing the grounded plane above the substrate 102, an etching non-uniformity proximate an edge of the substrate 102, typically produced during conventional plasma enhanced etch processes, may be reduced or eliminated. In some embodiments, by providing the grounding plane above the substrate 102 the inventors have observed an etch uniformity of less than about 5%, as compared to about an etch uniformity of about 30% that may be obtained utilizing conventional etch processes. The inventors believe that providing the grounded plane above the substrate 102 may modulate a local electrical flux produced during the etch process and redistribute an ion flux of the plasma, thereby providing the aforementioned reduction or elimination of the etching non-uniformity.

[0052] When positioned in the first position, the substrate support 100 may support the substrate 102 any distance below the ring 108 sufficient to reduce or eliminate the etching non-uniformities as described above. For example, in some embodiments, a distance between a bottom surface of the lip 1 14 and a top surface of the substrate 102 may be about 5 mm to about 20 mm.

[0053] Next, at 1006, a plasma enhanced etch process is performed on the substrate 102. The plasma enhanced etch process may be any type of plasma enhanced etch process suitable for semiconductor device fabrication. For example, in some embodiments, the plasma enhanced etch process may utilize a RF frequency power source ranging from about 2MHz to about 13MHz to ignite a process gas and as well as biasing the substrate to form a plasma to etch and/or redistribute material disposed atop a substrate. In some embodiments, the plasma enhanced etch process may utilize dual frequency power sources, such as utilizing high frequency {e.g., greater than about 27 MHz, such as about 27 MHz to about 162 MHz, or about 40 MHz) to ignite a process gas to form a plasma and simultaneously utilizing another frequency (e.g., from 2 MHz to 40 MHz) to lower the potential of the substrate so that the ions from the plasma can be accelerated to etch and/or redistribute material disposed atop a substrate. For example, referring to Figure 1 1A, in some embodiments, the deposition of a layer 1 108 of material atop the substrate 102 may result in the deposition of an excess of material 1 106 on a bottom surface 1 104 of a feature 1 102 formed in the substrate 102. By performing the above described etch process, the material 1 106 may be etched and redistributed on the sidewalls 1 1 10 of the feature 1 102, such as shown in Figure 1 1 B.

[0054] Next, at 1008, the substrate support 100 is positioned in a second position such that the substrate support 100 is in contact with the ring 108 and such that the ring 108 is not electrically coupled to the conductive shield 122, such as shown in Figure 2. When positioned in the second position, the lack of electrical coupling between the conductive shield 122 and the ring 108 causes the ring 108 to be electrically floating, and thus, not grounded.

[0055] Next, at 1010, a plasma enhanced deposition process is performed on the substrate 102. The deposition process may, for example, deposit a layer 1 1 12 atop at least portions of the substrate 102, for example such as shown in Figure 1 1 C. The inventors have observed that by performing the plasma enhanced deposition process while the substrate support 100 is disposed in the second position, a higher coverage of material 1 1 14 on a bottom surface 1 104 of the feature 1 102 may be obtained, as compared to conventional deposition processes. The inventors believe that by providing the substrate support 100 in the second position, and thereby maintaining the ring 108 in an electrically floating state, a maximum electrical potential of the ring 108 with respect to the electrical potential of the plasma may be obtained during the deposition process, thereby leading to a deposition of a layer of material atop the substrate 102 such that an amount of material 1 1 14 on the bottom surface 1 104 of the feature 1 102 is greater than an amount of material 1 1 14 on the sidewalls 1 1 10.

[0056] The deposition process may be any type of deposition process suitable to deposit materials for semiconductor device fabrication. For example, the deposition process may be a physical vapor deposition (PVD) process, a plasma enhanced chemical vapor deposition process (PECVD), or the like. The layer 1 1 12 may comprise any material suitable for semiconductor device fabrication, for example, a dielectric layer, a barrier layer, a conductive layer, a work function layer, or the like.

[0057] After the plasma enhanced deposition process is performed at 1010, the method generally ends and the substrate 102 may proceed for further processing to complete a desired semiconductor device. For example, in some embodiments, the substrate support 100 may be moved to another position (e.g., returning back to the first position shown in Figure 1 ) and an additional etch process may be performed to etch the layer deposited during the deposition process. Other processes may be performed, such as annealing, plasma treating, or the like.

[0058] Figure 12 depicts a schematic view of a process chamber suitable for use with the process kit described above in accordance with some embodiments of the present invention. Examples of suitable PVD chambers include the ALPSĀ® Plus and SIP ENCOREĀ® PVD process chambers, both commercially available from Applied Materials, Inc., of Santa Clara, California. Other process chambers from Applied Materials, Inc. or other manufactures may also benefit from the inventive method disclosed herein.

[0059] The process chamber 1200 contains a substrate support pedestal 1202 (e.g., the substrate support 100 described above) for receiving a substrate 1204 (e.g., the substrate 102 described above) thereon, and a sputtering source, such as a target 1206. The substrate support pedestal 1202 may be located within a grounded chamber wall 1208, which may be a chamber wall (as shown) or a grounded shield (a ground shield 1240 is shown covering at least some portions of the process chamber 1200 above the target 1206). In some embodiments, the ground shield 1240 could be extended below the target to enclose the pedestal 1202 as well.

[0060] The target 1206 may be coupled to a source distribution plate (not shown). The source distribution plate may be fabricated from suitable conductive materials to conduct power from one or more power sources to the target 1206. Any number of power sources may be utilized to provide power to the target 1206 to accommodate for a particular application or process performed in the process chamber 1200. For example, in some embodiments, a DC power source 1226 and RF power source 1224 may provide DC power and RF power, respectively, to the target 1206 via the source distribution plate. In such embodiments, the DC power source 1226 may be utilized to apply a negative voltage, or bias, to the target 1206. In some embodiments, a plurality of RF power sources may be provided (e.g., two or more) to provide RF energy in a plurality of the above frequencies. [0061] The ground shield 1240 may be provided to cover the outside surfaces of the lid of the process chamber 1200. The ground shield 1240 may be coupled to ground, for example, via the ground connection of the chamber body. The ground shield 1240 may comprise any suitable conductive material, such as aluminum, copper, or the like. An insulative gap 1239 is provided between the ground shield 1240 and the outer surfaces of the distribution plate, and the target 1206 to prevent the RF and DC energy from being routed directly to ground. The insulative gap may be filled with air or some other suitable dielectric material, such as a ceramic, a plastic, or the like.

[0062] The target 1206 may be supported on a grounded conductive aluminum adapter 1242 through a dielectric isolator 1244. The target 1206 comprises a material to be deposited on the substrate 1204 during sputtering, such a metal or metal oxide. In some embodiments, a backing plate (not shown) may be coupled to the source distribution plate-facing surface 1232 of the target 1206. The backing plate may comprise a conductive material, such as copper-zinc, copper-chrome, or the same material as the target, such that RF and DC power can be coupled to the target 1206 via the backing plate. Alternatively, the backing plate may be non- conductive and may include conductive elements (not shown) such as electrical feedthroughs or the like for coupling RF and DC power to the target 1206.

[0063] The substrate support pedestal 1202 has a substrate support surface 1210 facing the principal surface of the target 1206 and supports the substrate 1204 to be processed. In some embodiments, a housing 1220 {e.g., the housing 130 described above) may be disposed about at least a portion of the substrate support pedestal 1202. The substrate support pedestal 1202 may support the substrate 1204 in a processing volume 1248 of the process chamber 1200. The processing volume 1248 is defined as the region above the substrate support pedestal 1202 during processing (for example, between the target 1206 and the substrate support pedestal 1202 when in a processing position).

[0064] In some embodiments, the substrate support pedestal 1202 may be vertically movable through a bellows 1250 connected to a bottom chamber wall 1252 to allow the substrate 1204 to be transferred onto the substrate support pedestal 1202 through a load lock valve (not shown) in the lower portion of processing the process chamber 1200 and thereafter raised to one or more positions for processing (e.g., as described above).

[0065] One or more processing gases may be supplied from a gas source 1254 through a mass flow controller 1256 into the lower part of the process chamber 1200. An exhaust port 1258 may be provided and coupled to a pump (not shown) via a valve 1260 for exhausting the interior of the process chamber 1200 and facilitating maintaining a desired pressure inside the process chamber 1200.

[0066] In some embodiments, one or more power sources (an RF bias power source 1262 and DC power source 1264 shown) may be coupled to the substrate support pedestal 1202. When present, the RF bias power source 1262 may be coupled to the substrate support pedestal 1202 to induce a negative DC bias on the substrate 1204. In addition, in some embodiments, a negative DC self-bias may form on the substrate 1204 during processing.

[0067] In some embodiments, the process chamber 1200 may further include a shield 1274 [e.g., the conductive shield 122 described above) connected to a ledge 1276 of the adapter 1242. The adapter 1242 in turn is sealed and grounded to the chamber wall 1208. Generally, the shield 1274 extends downwardly along the walls of the adapter 1242 and the chamber wall 1208 downwardly to below an upper surface of the substrate support pedestal 1202 and returns upwardly until reaching an upper surface of the substrate support pedestal 1202, forming an inwardly extending ledge 1228 {e.g., the inwardly extending ledge 154 described above). In some embodiments, one or more grounding straps 1230 {e.g., the first grounding strap 128 described above) may electrically couple the shield 1274 to the housing 1220. In some embodiments, a ring 1286 {e.g., the ring 108 described above) rests on the top of the inwardly extending ledge 1228 of the shield 1274. An additional deposition ring 1222 {e.g., the deposition ring 106 described above) may be used to shield the periphery of the substrate 1204 during processing.

[0068] In some embodiments, a magnet 1290 may be disposed about the process chamber 1200 for selectively providing a magnetic field between the substrate support pedestal 1202 and the target 1206. For example, as shown in Figure 12, the magnet 1290 may be disposed about the outside of the chamber wall 121208 in a region just above the substrate support pedestal 1202. In some embodiments, the magnet 1290 may be disposed additionally or alternatively in other locations, such as adjacent the adapter 1242. The magnet 1290 may be an electromagnet and may be coupled to a power source (not shown) for controlling the magnitude of the magnetic field generated by the electromagnet.

[0069] A controller 1218 may be provided and coupled to various components of the process chamber 1200 to control the operation thereof. The controller 1218 includes a central processing unit (CPU) 1212, a memory 1214, and support circuits 1216. The controller 1210 may control the process chamber 1200 directly, or via computers (or controllers) associated with particular process chamber and/or support system components. The controller 1218 may be one of any form of general-purpose computer processor that can be used in an industrial setting for controlling various chambers and sub-processors. The memory, or computer readable medium, 1214 of the controller 1218 may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, optical storage media (e.g., compact disc or digital video disc), flash drive, or any other form of digital storage, local or remote. The support circuits 1216 are coupled to the CPU 1212 for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like. Inventive methods as described herein may be stored in the memory 1214 as software routine that may be executed or invoked to control the operation of the process chamber 1200 in the manner described herein. The software routine may also be stored and/or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by the CPU 1212.

[0070] Thus, embodiments of methods and process kits for processing substrates are provided herein. In at least some embodiments, the inventive process kit may facilitate selective grounding of a process kit ring to accommodate for the requirements of a desired process. In addition, when grounded, the inventive process kit may provide a more robust electrical coupling of the process kit ring to conductive process chamber components as compared to utilizing conventionally utilized process kits.

[0071] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.