MECHANISM

FIELD

[0001] The present disclosure relates generally to apparatus and methods for improving deposition uniformity. In particular, embodiments of the disclosure are directed to a process kit design for an in-chamber heater and substrate rotating mechanism.

BACKGROUND

[0002] In many deposition chambers, both atomic layer deposition and chemical vapor deposition, rotating pedestal/heaters are used to improve non- uniformity. In most cases, non-uniformity comes from non-uniform chemical delivery, flow distribution, chamber features, and temperature non-uniformity from the chamber body and surrounding components. Using a rotating pedestal can distribute the local effect of these variations and improve the non-uniformity.

[0003] However, in some cases, non-uniformity can be contributed by the pedestal or the heater itself, especially when the substrate (wafer) sits on or contacts the heater. The impact of local non-uniform temperature distribution can have a significant impact on the uniformity of deposition. This non-uniform temperature distribution can come from heater element layout, local features like lift pin holes, non-uniform radiative heat loss, non-uniform contact surface or gap, or other reasons.

[0004] Therefore, there is a need in the art for apparatus and methods to eliminate or reduce local non-uniform temperature distribution resulting from pedestal/heater to substrate contact.

SUMMARY

[0005] Embodiments of the present disclosure are directed process kits for use with an in-chamber heater and substrate rotating mechanism. In some embodiments consistent with the present disclosure, a process kit for use with a rotatable substrate support heater pedestal for supporting a substrate in a process chamber may include an upper edge ring including a top ledge and a skirt the extends downward from the top ledge, a lower edge ring that at least partially supports the upper edge ring and aligns the upper edge ring with the substrate support heater pedestal, a bottom plate disposed on a bottom of the process chamber that supports the upper edge ring when the substrate support heater pedestal is in a lowered non- processing position, and a shadow ring that couples with the upper edge ring when the substrate support heater pedestal is in a raised processing position.

[0006] In some embodiments, a process kit includes an upper edge ring including a top ledge and a skirt the extends downward from the top ledge, wherein the top ledge of the upper edge ring is configured to support the substrate in a spaced-apart relation to a support surface of the substrate support heater pedestal to facilitate repositioning of the substrate relative to the support surface of the substrate support heater pedestal, and wherein the skirt covers the outer edges of the substrate support heater pedestal to prevent heat loss from the substrate support heater pedestal, and a lower edge ring that at least partially supports the upper edge ring and aligns the upper edge ring with the substrate support heater pedestal.

[0007] In some embodiments, a rotatable substrate support heater pedestal and process kit for supporting a substrate in a process chamber includes a primary substrate support having a support surface to support the substrate during processing, where the substrate support heater pedestal includes a shaft connected to an actuator to move the substrate support heater pedestal vertically and rotationally about an axis of the shaft, and a process kit comprising an upper edge ring including a top ledge and a skirt the extends downward from the top ledge, wherein the top ledge of the upper edge ring is configured to support the substrate in a spaced-apart relation to a support surface of the substrate support heater pedestal to facilitate repositioning of the substrate relative to the support surface of the substrate support heater pedestal, and a lower edge ring that at least partially supports the upper edge ring and aligns the upper edge ring with the substrate support heater pedestal.

[0008] Other and further embodiments of the present invention are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 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.

[0010] Figure 1 shows a side cross-sectional view of a processing chamber in accordance with one or more embodiment of the disclosure;

[0011] Figure 2 shows a partial side cross-sectional view of a processing chamber in accordance with one or more embodiment of the disclosure;

[0012] Figure 3A depicts a bottom view of the upper edge ring in accordance with one or more embodiment of the disclosure;

[0013] Figure 3B depicts a side cross-sectional view of the upper edge ring in accordance with one or more embodiment of the disclosure;

[0014] Figure 4A depicts a top view of the lower edge ring in accordance with one or more embodiment of the disclosure;

[0015] Figure 4B depicts a side cross-sectional view of an alignment cone cutout in accordance with one or more embodiment of the disclosure;

[0016] Figure 4C depicts bottom view of the lower edge ring in accordance with one or more embodiment of the disclosure;

[0017] Figure 5 depicts a top view of the bottom plate ring in accordance with one or more embodiment of the disclosure;

[0018] Figure 6A depicts a bottom view of the shadow ring in accordance with one or more embodiment of the disclosure; and

[0019] Figure 6B depicts a side cross-sectional view of the shadow ring.

[0020] 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

[0021] Embodiments of the present disclosure are directed process kits for use with an in-chamber heater and substrate rotating mechanism. In some embodiments consistent with the present disclosure, a substrate will be decoupled from the heater pedestal substrate support using an upper edge ring while the heater pedestal is lowered. In some embodiments, a skirt of the upper edge ring will remain on a bottom plate and the substrate will sit on a ledge of the upper edge ring. After rotating the decoupled heater pedestal with respect to the substrate, the heater pedestal can be raised to a processing position to chuck the substrate again. The process kit also includes a lower edge ring that can be aligned with upper edge ring during substrate and heater pedestal coupling stage. The process kit may further include a bottom plate that will act as a base support for the upper edge ring ensuring minimum contact with upper edge ring skirt. The bottom plate will also provide centering features to center the bottom plate relative to chamber body and pumping liner. The process kit may further include a shadow ring that can be coupled with upper edge ring and aligned with alignment pins at a processing position of the heater pedestal. In some embodiments, the shadow ring also has alignment tabs to center the shadow ring relative to pumping liner. The inventive process kits consistent with the present disclosure described herein advantageously facilitates decoupling of heater pedestal with respect to the substrate to facilitate in chamber rotation of the heater pedestal with respect to the substrate to eliminate or reduce local non-uniform temperature distribution resulting from pedestal/heater to substrate contact.

[0022] FIG. 1 depicts a side cross-sectional view of a process chamber 100 in accordance with one or more embodiment of the disclosure. The process chamber 100 includes a chamber body 104 with a sidewall 103, a bottom 105 and a lid assembly 106 that encloses a process volume 108. The substrate support system 102 is at least partially disposed in the process volume 108 and can support a substrate 1 10 that has been transferred to the process volume 108 through a port 1 12 formed in the chamber body 104. A process kit is included in the processing volume 108 that includes at least one of an upper edge ring 1 16, a lower edge ring 180, a bottom plate 169, and/or a shadow ring 182.

[0023] The substrate support system 102 includes a primary substrate support

1 13, such as a pedestal 1 14 and a thermal element 120. In addition, portions of the process kit comprise a secondary substrate support 1 15, such as an upper edge ring 1 16 and lower edge ring 180. The secondary substrate support 1 15 may be used to intermittently support the substrate 1 10 above the primary substrate support 1 13. The pedestal 1 14 includes a support surface 1 18 that is adapted to contact (or be in proximity to) a major surface of the substrate 1 10 during processing. Thus, the pedestal 1 14 serves as a primary supporting structure for the substrate 1 10 in the process chamber 100.

[0024] The pedestal 1 14 may include a thermal element 120 to control the temperature of the substrate 1 10 during processing. The thermal element 120 can be, for example, a heater or cooler that is positioned on top of the pedestal 1 14 or within the pedestal. The heater or cooler can be a separate component that is coupled to the top of the pedestal 1 14 or can be an integral part of the pedestal

1 14. In some embodiments, the thermal element 120 is embedded within the pedestal body (as shown in Figures 1 and 2). In one or more embodiment, the embedded thermal element 120 may be a heating or cooling element or channel, utilized to apply thermal energy to the pedestal 1 14 body that is absorbed by the substrate 1 10. Other elements may be disposed on or embedded within the pedestal 1 14, such as one or more electrodes, sensors and/or vacuum ports. The temperature of the substrate 1 10 may be monitored by one or more sensors (not shown). The embedded thermal element 120 may be zone controlled such that temperature at different areas of the pedestal 1 14 body may be individually heated or cooled. However, due to extenuating factors, such as imperfections in the pedestal 1 14 and/or non- uniformities in the substrate 1 10, the embedded thermal element 120 may not be able to apply thermal energy uniformly across the entire support surface 1 18 and/or the substrate 1 10. These extenuating factors can create non-uniform temperature distribution across the substrate 1 10, which can result in non- uniform processing of the substrate. [0025] The pedestal 1 14 can be coupled to an actuator 126 via shaft 121 that provides one or more of vertical movement (in the z-axis), rotational movement (about axis A) and may also provide angular movement (relative to axis A). Vertical movement may be provided by the actuator 126 to allow the substrate 1 10 to be transferred between the upper edge ring 1 16 and the support surface 1 18. The shaft 121 passes through the bottom 105 of the processing chamber 100 via opening 127. An isolated processing environment can be preserved by bellows 154 surrounding opening 127 and connected to a portion of the shaft 121 .

[0026] In the processing position, as shown in FIG. 1 , the upper edge ring 1 16 would be in proximity to the pedestal 1 14 and may circumscribe (i.e., surround) the pedestal 1 14 such that a lower surface of the substrate 1 10 would be supported by the pedestal 1 14. In the processing position, the upper edge ring 1 16 may be in contact with the pedestal 1 14 and/or the thermal element 120. In the embodiment shown, where the thermal element 120 is a separate component, the upper edge ring 1 16 is shown supported by a peripheral shoulder 122 formed around the circumference of the thermal element 120. Those skilled in the art will understand that this is merely representative of one possible configuration and should not be taken as limiting the scope of the disclosure. In some embodiments, the pedestal 1 14 has the thermal element 120 embedded within and the upper edge ring 1 16 can be supported on a peripheral shoulder 122 formed around the circumference of the pedestal 1 14.

[0027] The upper edge ring 1 16 can function as a temporary substrate support during processing. The upper edge ring 1 16 may be utilized for supporting the substrate 1 10 in a spaced-apart relation to the support surface 1 18 of the pedestal 1 14 as necessary (as shown in FIG. 2 ), which may facilitate repositioning of the substrate 1 10 relative to the support surface 1 18 of the pedestal 1 14. The upper edge ring 1 16 may include recesses or slots formed therein that are sized to allow a robot blade 109 to facilitate robotic substrate transfer into and out of the process volume 108.

[0028] Details of the upper edge ring 1 16 are described below with respect to Figures 3A-3B. Specifically, Figure 3A depicts a bottom view of the upper edge ring 1 16, Figure 3B depicts a side cross-sectional view of the upper edge ring 1 16, and the upper edge ring 1 16 includes and annular body 322 having a central opening 314. The upper edge ring 1 16 includes a top ledge 305 having a bottom surface 306 and a top surface 312. The upper edge ring 1 16 further includes a lower skirt 308 that hangs below the upper ledge and having an inner surface 310. The lower skirt 308 covers the heater 1 14/120 at the edge to prevent heat loss from the heater. In some embodiments the height of the lower skirt 308 may be about 1 inch to about 3 inches. In some embodiments, the upper edge ring 1 16 has an inner diameter 316 of about 12 inches to about 15 inches and an outer diameter 318 of about 12.5 inches to about 15.5 inches. In some embodiments, the inner diameter 320 of the top ledge central opening is about 10.5 inches to about 13.5 inches.

[0029] The upper edge ring 1 16 includes one or more features as shown in Figures 3A-3B. In some embodiments, the upper edge ring 1 16 includes one or more top features 324 at the inner diameter 320 of the top ledge. In some embodiments, the top feature 324 may be an annular angled edge such that a gap of about 15 mils to about 25 mils (e.g., a 20 mils gap ± 5 mils) between the substrate and the upper edge ring 1 16 is maintained to facilitate heater edge gas purging and prevent chemical deposition at the sides.

[0030] In some embodiments, the upper edge ring 1 16 includes one or more alignment holes 302. The alignment holes 302 facilitate alignment of the upper edge ring 1 16 with the lower edge ring 180 during in-chamber heater rotation. In some embodiments, there may be three alignment holes 302 spaced equidistantly (e.g., 120 degrees) apart. In some embodiments, alignment holes 302 may be oval in shape. In some embodiments, alignment holes 302 may have a chamfered opening. In some embodiments, alignment holes 302 may have an opening between about 0.1 inches to about 0.5 inches.

[0031] In some embodiments, the upper edge ring 1 16 includes one or more alignment tabs 304 that extend downward from the lower surface 306 of the top ledge 305. The alignment tabs 304 facilitate alignment of the upper edge ring 1 16 with the shadow ring 182 when the heater moves to a processing position. In some embodiments, there may be three alignment tabs 304 spaced equidistantly (e.g., 120 degrees) apart. In some embodiments, alignment tabs 304 may extend downward from the lower surface 306 of the top ledge 305 by about 0.1 inches to about 0.2 inches.

[0032] The lower edge ring 180 is disposed below the upper edge ring 1 16 and facilitates alignment and support of the upper edge ring 1 16, among other things. Details of the lower edge ring 180 are described below with respect to Figures 4A- 4C. Specifically, Figure 4A depicts a top view of the lower edge ring 180, Figure 4B depicts a side cross-sectional view of an alignment cone cutout 404, and Figure 4C depicts bottom view of the lower edge ring 180. The lower edge ring 180 includes an annular body 402 having a central opening 414 and an inner surface 410. In some embodiments, the lower edge ring 180 has an inner diameter 422 of about 1 1 inches to about 14 inches and an outer diameter 420 of about 12 inches to about 15 inches.

[0033] The lower edge ring 180 includes one or more features as shown in Figures 4A-4C. In some embodiments, the lower edge ring 180 includes a plurality of cone cut outs 404 disposed on a top surface of the lower edge ring 180. The plurality of cone cut outs 404 enable the shadow ring 182 having a lower purge ring to align a substrate notch cover of the shadow ring 182 to be disposed over or otherwise cover the substrate notch during processing. In some embodiments, there may be 12 cone cut outs 404 spaced equidistantly (e.g., 30 degrees) apart. Figure 4B depicts a side cross-sectional view of a cone cut out 404. In some embodiments, each cone cut out 404 may be about 0.1 to about 0.15 inches deep.

[0034] In some embodiments, the lower edge ring 180 includes a plurality of angled cut outs 406 formed along the outer periphery/diameter of the lower edge ring 180. The plurality of angled cut outs 406 facilitates alignment of the lower edge ring 180 with the upper edge ring 1 16 during in-chamber heater rotation. In some embodiments, there may be 12 angled cut outs 406 spaced equidistantly (e.g., 30 degrees) apart.

[0035] In some embodiments, the lower edge ring 180 includes a plurality of bottom alignment tabs 412 formed on a bottom surface of the lower edge ring 180. The plurality of bottom alignment tabs 412 facilitates alignment of the lower edge ring 180 with the heater pedestal 1 14/120. In some embodiments, there may be 3 bottom alignment tabs 412 spaced equidistantly (e.g., 120 degrees) apart. [0036] Referring to Figure 2, an exemplary process kit is shown using an apparatus in accordance with one or more embodiments of the disclosure. When loading or unloading a substrate 1 10, the substrate 1 10 is supported by a set of lift pins 152. While two lift pins 152 are shown in Figure 1 , those skilled in the art will understand that there are generally three or more lift pins 152 to support the substrate 1 10.

[0037] The substrate 1 10 is brought into the process volume 108 by robot 109 through port 1 12 in the sidewall 103 of the process chamber 100. The port 1 12 can be, for example, a slit valve. A set of lift pins 152 are raised into the loading/unloading position shown in Figure 2 and the substrate 1 10 is positioned on the lift pins 152. The lift pins 152 can pass through openings in the body of the pedestal 1 14 and thermal element 120. When not in use, the lift pins 152 can be lowered to be out of the way during processing. The lift pins 152 can be part of a lift pin assembly 156 that is connected to the shaft 121 so that the lift pin assembly 156 rotates with the shaft 121 and remain aligned with the openings in the pedestal 1 14.

[0038] As shown in Figure 1 , the lift pins 152 are lowered, which lowers the substrate 1 10 onto the upper edge ring 1 16. The upper edge ring 1 16 has an inner lip 161 , as shown in Figure 3B, to support an outer peripheral edge of the substrate 1 10. The upper edge ring 1 16 is generally ring shaped with a central opening 314 defined by the inner diameter of the ring. The inner lip 161 is formed at the inner diameter of the upper edge ring 1 16.

[0039] The pedestal 1 14 of some embodiments includes a peripheral shoulder 122 around the outer peripheral edge of the pedestal 1 14. The peripheral shoulder 122 of some embodiments is sized to fit within the outer diameter 318 of the upper edge ring 1 16 with a small clearance. For example, the clearance can be less than or equal to about 5 mm, 4 mm, 3 mm, 2 mm, 1 mm or 0.5 mm.

[0040] The lip 161 of the upper edge ring 1 16 in some embodiments is sized to rest on the peripheral shoulder 122 of the pedestal 1 14 at a level (or height) equal to or lower than support surface 1 18 of the primary substrate support 1 13. The difference in heights between the lip 161 and the support surface 1 18 can be, for example, about 1 mm to about 10 mm, or, for example, about 0.04 inch to about 0.40 inch.

[0041] The upper edge ring 1 16 has a foot 165 to support the upper edge ring 1 16 when in the lowered position. In some embodiments, the foot 165, including the body of the upper edge ring 1 16 between the foot and lip 161 , is sized to support the edge ring above the pedestal 1 14 when the pedestal is in the decoupled position. In one or more embodiments, there is a bottom plate 169 located within the process chamber 100. The bottom plate 169 can be arranged and sized to contact the foot 165 of the edge ring 1 16 to stop the downward movement of the upper edge ring 1 16. The size of the bottom plate 169 can be adjusted to change the lowest height that the lip 161 of the upper edge ring 1 16 can be adjusted.

[0042] The bottom plate 169 can be positioned in any suitable location depending on, for example, the components of the process chamber, the size of the edge ring and the position of the lip at the lowest height. In some embodiments, the bottom plate 169 is positioned adjacent to the bottom 105 of the process chamber 100. In some embodiments, the process chamber includes a reflector to reflect radiant energy toward the pedestal 1 14 or upper edge ring 1 16. In one or more embodiments, the bottom plate 169 is the same component as the reflector.

[0043] Details of the bottom plate 169 are described with respect to Figure 5 which depicts a top view of the bottom plate 169. The bottom plate 169 includes and annular body 501 having a central opening 514. The bottom plate 169 includes a bottom ledge 512. In some embodiments, the bottom plate 169 has an inner diameter 520 of about 12.0 inches to about 15.0 inches and an outer diameter 522 of about 12.5 inches to about 15.5 inches. In some embodiments, the inner diameter 524 of the bottom ledge 512 central opening is about 10.5 inches to about 13.5 inches.

[0044] In some embodiments, the bottom plate 169 includes one or more features as shown in Figure 5. In some embodiments, the bottom plate 169 includes one or more centering tabs 504 that jut out along a periphery of the outer diameter of the bottom plate 169. In some embodiments, there may be 3 centering tabs 504 spaced equidistantly (e.g., 120 degrees) apart. The centering tabs 504 facilitate alignment/centering of the bottom plate with respect to the chamber body. The top surface of each of the plurality of centering tabs may function as a landing pad 516. The landing pads 516 are used to contact and support the upper edge ring 1 16 during substrate decoupling with minimum heat loss from the upper edge ring 1 16. Thus, the landing pads 516 may be formed of a material or coating that minimizes heat loss from the upper edge ring 1 16 when in contact.

[0045] In some embodiments, the bottom plate 169 includes a plurality of angled cut outs 502, similar to angled cut outs 406, formed along the outer periphery/diameter of the bottom plate 169. The plurality of angled cut outs 502 provide clearance and enable quick pressure equalization between a top section and a bottom section of the chamber during in-chamber heater rotation. In some embodiments, there may be 12 angled cut outs 502 spaced equidistantly (e.g., 30 degrees) apart.

[0046] In some embodiments, one or more alignment tabs 506 may be formed along the outer periphery/diameter of the bottom plate 169 to align the bottom plate, for example, with a pumping liner.

[0047] The aforementioned shadow ring 182 is described in detail with respect to Figures 6A and 6B. Specifically, Figure 6A depicts a bottom view of the shadow ring 182. The shadow ring 182 includes an annular body 610 having a lower surface 608 and a central opening 614. In some embodiments, the shadow ring 182 has an inner diameter 632 of about 10 inches to about 13 inches and an outer diameter 630 of about 12.5 inches to about 15.5 inches.

[0048] The shadow ring 182 includes one or more features as shown in Figures 3A- 3B. In some embodiments, the shadow ring 182 includes one or more top features 620 at the inner diameter 632 of the annular body 610. In some embodiments, the top feature 620 may be an annular angled edge 618.

[0049] In some embodiments, the shadow ring 182 includes one or more alignment pins 602 that extend downward from the lower surface 608. The alignment pins 602 facilitate alignment of the shadow ring 182 with the upper edge ring 1 16 when moving the heater pedestal 1 14 to a substrate processing position. In some embodiments, there may be three alignment pins 602 spaced equidistantly (e.g., 120 degrees) apart. In some embodiments, alignment pins 602 may extend downward from the lower surface 608 by about 0.1 inches to about 0.5 inches.

[0050] In some embodiments, the shadow ring 182 includes one or more alignment tabs 604 that extend downward from the lower surface 608. The alignment tabs 604 facilitate alignment of the shadow ring 182 with the pumping liner, for example, during decoupling of the heater pedestal 1 14 from the shadow ring 182. In some embodiments, there may be three alignment tabs 304 spaced equidistantly (e.g., 120 degrees) apart. In some embodiments, alignment tabs 604 may extend downward from the lower surface 608 by about 0.1 inches to about 0.3 inches.

[0051] In some embodiments, the shadow ring 182 includes one or more notch cover features 606 that extend inward from the inner diameter 632 edge. The notch cover 606 covers the substrate notch during processing to prevent deposition on the heater pedestal 1 14 through the notch opening.

[0052] Referring back to Figures 1 and 2, in embodiments consistent with the present disclosure, the primary substrate support 1 13 is raised so that the support surface 1 18 contacts the bottom side of the substrate 1 10, thermally coupling the support surface 1 18 and the substrate 1 10. During lifting of the primary substrate support 1 13, the lip 161 of the edge ring contacts the peripheral shoulder 122 of the pedestal 1 14. The upper edge ring 1 16 is movable in a vertical direction (z-axis) by contact and interaction with the pedestal 1 14 through the peripheral shoulder 122. In some embodiments, the upper edge ring 1 16 is movable in the vertical direction (z-axis) only through interaction with the pedestal 1 14. Stated differently, in some embodiments, the upper edge ring 1 16 does not have an independent lifting mechanism or actuator.

[0053] The primary substrate support 1 13 is raised high enough that the foot 165 of the upper edge ring 1 16 ceases contact with the bottom plate 169. The lip of the upper edge ring 1 16 can be positioned within the peripheral shoulder 122 adjacent the substrate 1 10 so that the substrate 1 10 is in substantially full contact with the support surface 1 18. The lip 161 of the upper edge ring 1 16 may be slightly lower than the support surface 1 18 so that there is a small gap. The gap can be minimized based so that there is little or no impact to process uniformity. [0054] The process has been described with the substrate 1 10 being loaded with the upper edge ring 1 16 only contacting the substrate when the lift pins 152 are lowered. However, those skilled in the art will understand that this is merely representative of one possible method and should not be taken as limiting the scope of the disclosure. In some embodiments, the primary substrate support 1 13 is raised or the lift pins 152 are lowered so that the substrate makes contact with the support surface 1 18 at the same time or before the lip 161 of the upper edge ring 1 16.

[0055] The substrate can be processed while in the coupled position. The process chamber 100 may be a deposition chamber, an etch chamber, an ion implant chamber, a plasma treatment chamber, or a thermal process chamber, among others. In the embodiment shown in FIG. 1 , the process chamber is a deposition chamber and includes a showerhead assembly 128. The process volume 108 may be in selective fluid communication with a vacuum system 130 to control pressures therein. The showerhead assembly 128 may be coupled to a process gas source 132 to provide process gases to the process volume 108 for depositing materials onto the substrate 1 10. The showerhead assembly 128 may also include a temperature control element 134 for controlling the temperature of the showerhead assembly 128. The temperature control element 134 may be a fluid channel that is in fluid communication with a coolant source 136.

[0056] To counter the thermal non-uniformity that may be present on the surface of the substrate 1 10 (which may be determined by monitoring temperature of the substrate 1 10), the substrate 1 10 may be repositioned relative to the support surface 1 18. The hot or cold spots present on the surface of the substrate 1 10 are indicative of hot or cold spots in or on the support surface 1 18 of the pedestal body.

[0057] After the substrate 1 10 is processed to some predetermined extent, the primary substrate support 1 13 is lowered to decouple the support surface 1 18 from the substrate 1 10. The decoupling causes the upper edge ring 1 16 to lower in the process chamber 100 so that the foot 165 contacts the bottom plate 169. The upper edge ring 1 16 stops moving in the downward direction once the foot 165 rests on the bottom plate 169. With the upper edge ring 1 16 stopped, further downward movement of the pedestal 1 14 (and support surface 1 18) causes the substrate 1 10 to be supported by the upper edge ring 1 16 and decoupled from the support surface 1 18. As the support surface 1 18 is further lowered, a gap is created between the support surface 1 18 and the substrate 1 10. In some embodiments, the upper edge ring 1 16 is movable with the movement of the primary support substrate 1 13 and not independently movable.

[0058] Once decoupled, the primary substrate support 1 13 is rotated with actuator 126 by a predetermined amount. After rotation, the decoupled substratel 10 and support surface 1 18 are re-coupled, moving the primary substrate support 1 13 upward to a position where the substrate 1 10 and support surface are 1 18 touching. This coupling/process/de-coupling/rotation cycle is repeated until the process is completed.

[0059] Each rotation of the primary substrate support 1 13 is by 1/nth of the total amount, where n is one or more of a rotational degree or a fraction of the deposition time. For example, if the n is a rotational degree that is four-fold, the primary substrate support 1 13 will be rotated 90° about the axis A. The rotational degree is the amount of rotation that occurs in separate steps to equal a complete circle of 360° based on the number of iterations for coupling/processing/decoupling. If there are twelve coupling/decoupling iterations, each rotation of the primary substrate support 1 13 will be 1/12 of 360° or 30°.

[0060] In some embodiments, n is based on the predetermined deposition time for the process. For example, if a ten minute process had ten iteration of coupling/decoupling, each rotation of the primary substrate support 1 13 would be 36°, so that a complete circle of 360° is made by the end of the process.

[0061] In some embodiments, the coupling/processing/decoupling/rotation iteration occurs a total of Xn times, where n is one or more of a rotational degree or a fraction of the deposition time and X is a positive integer. For example, if the primary substrate support 1 13 is rotated 90° during each iteration; then n would be 360790° or 4 to make a complete circle. The complete circle can be made more than one time so that X is greater than 1 . For example, if the primary substrate support 1 13 is rotated 90° during each iteration and there are a total of eight iterations, then n would be 360 90° = 4 and N would be 2; meaning that two complete revolutions of the primary substrate support 1 13 occur.

[0062] In another embodiment, the pedestal 1 14 may be an electrostatic chuck and the pedestal 1 14 may include one or more electrodes 125 (as shown in FIG. 1 ). For example, the pedestal 1 14 may be coupled to a power element 140A that may be a voltage source providing power to the one or more electrodes 125. The voltage source may be a radio frequency (RF) controller or a direct current (DC) controller. In another example, the pedestal 1 14 may be made of a conductive material and function as a ground path for RF power from a power element 140B distributed by the showerhead assembly 128. Thus, the process chamber 100 may perform a deposition or etch process utilizing RF or DC plasmas. As these types of plasmas may not be perfectly concentric or symmetrical, RF or DC hot spots (i.e., electromagnetic hot spots) may be present on the substrate 1 10. These electromagnetic hot spots may create non-uniform deposition or non-uniform etch rates on the surface of the substrate 1 10.

[0063] 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.