Rinse ring for reducing substrate backside deposition

Abstract

Embodiments of a flush ring for use in a processing chamber are provided herein. In some embodiments, a rinse ring includes an annular body having an inner portion and an outer portion, where the inner portion includes an inner surface of the annular body, the inner surface including a first inner sidewall, a second inner sidewall, and a third inner sidewall, where the inner portion has an upper inner recess defining the first inner sidewall and a lower inner recess defining the second inner sidewall, wherein the third inner side wall is disposed between the first inner side wall and the second inner side wall, and wherein the first inner side wall and the second inner side wall are disposed radially outward from the third inner side wall.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to substrate processing apparatus. Background Art

[0002] Deposition process chambers are widely used in the semiconductor processing industry to deposit thin layers of materials onto substrates. For example, chemical vapor deposition (CVD) chambers can be used to deposit thin layers of materials via chemical reactions of one or more process gases. During deposition, one or more process gases can diffuse to the backside of the substrate and cause undesirable backside deposition, substrate delamination, and particle problems.

[0003] Thus, the inventors herein provide embodiments of an improved flush ring for use in a deposition chamber. Summary of the invention

[0004] Embodiments of flush rings for use in processing chambers are provided herein. In some embodiments, the flush ring comprises: an annular body having an interior and an exterior, wherein the interior comprises an inner surface of the annular body, the inner surface comprising a first inner sidewall, a second inner sidewall, and a third inner sidewall, wherein the interior has an upper inner recess defining the first inner sidewall and a lower inner recess defining the second inner sidewall, wherein the third inner sidewall is disposed between the first inner sidewall and the second inner sidewall, and wherein the first inner sidewall and the second inner sidewall are disposed radially outward from the third inner sidewall.

[0005] In some embodiments, a processing kit for use in a processing chamber includes a flush ring, the flush ring comprising an annular body having an interior and an exterior, wherein the interior has an upper inner recess defining a first inner sidewall of the annular body and an inner upper wall extending horizontally, and wherein the interior has a lower inner recess defining a second inner sidewall and an inner lower wall of the annular body, wherein a third inner sidewall is disposed between the first inner sidewall and the second inner sidewall, wherein the second inner sidewall is disposed radially outward from the first inner sidewall, wherein a first height of the first inner sidewall is less than a second height of the second inner wall, and wherein the first height is less than a third height of the third inner sidewall.

[0006] In some embodiments, a substrate support comprises: a pedestal configured to support a substrate and having one or more purge gas inlets; and a purge ring comprising an annular body disposed on an outer flange of the pedestal radially outward from the one or more purge gas inlets, the purge ring having an interior and an exterior, wherein the interior has an upper inner recess defining a first inner sidewall and an inner upper wall of the annular body, and a lower inner recess defining a second inner sidewall and an inner lower wall of the annular body, wherein a third inner sidewall is disposed between the first inner sidewall and the second inner sidewall, wherein the third inner sidewall is disposed radially inward from the first inner sidewall and the second inner wall, wherein a first height of the first inner sidewall is less than a second height of the second inner wall, and wherein the pedestal and the purge ring together define a gas flow path along the inner lower wall, the third inner sidewall, and the inner upper wall of the purge ring.

[0007] Other and further embodiments of the disclosure are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The embodiments of the present disclosure, briefly summarized above and discussed in more detail below, can be understood by reference to the illustrative embodiments of the present disclosure depicted in the accompanying drawings. However, the accompanying drawings only illustrate common embodiments of the present disclosure and are therefore not to be considered limiting in scope, as the present disclosure may admit to other equally effective embodiments.

[0009] Figure 1 Depicted is a schematic side view of a processing chamber in accordance with at least some embodiments of the present disclosure.

[0010] Figure 2 Depicted are schematic cross-sectional views of a portion of a substrate support and process kit in accordance with at least some embodiments of the present disclosure.

[0011] Figure 3 Depicted is an isometric view of a flush ring in accordance with at least some embodiments of the present disclosure.

[0012] Figure 4 Depicted is a bottom view of a flush ring in accordance with at least some embodiments of the present disclosure.

[0013] Figure 5 Depicted are cross-sectional views of flush rings in accordance with at least some embodiments of the present disclosure.

[0014] Figure 6 Depicted are cross-sectional views of flush rings in accordance with at least some embodiments of the present disclosure.

[0015] Figure 7 Depicted is an isometric view of a flush ring in accordance with at least some embodiments of the present disclosure.

[0016] Figure 8 Depicted is a bottom view of a flush ring in accordance with at least some embodiments of the present disclosure.

[0017] Fig. 9 Depicted are cross-sectional views of flush rings in accordance with at least some embodiments of the present disclosure.

[0018] For ease of understanding, the same reference numerals have been used to identify the same elements common to the figures where possible. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. DETAILED DESCRIPTION

[0019] Embodiments of a flush ring for use in a process chamber are provided herein. In some embodiments, the process chamber is a deposition chamber, such as a CVD chamber. In some embodiments, the CVD chamber is configured for tungsten deposition. The flush ring is designed to increase the edge flush flow velocity along the back side of the substrate to advantageously prevent the front side gas from reaching the back side of the substrate.

[0020] Figure 1 A schematic side view of a processing chamber 100 is depicted in accordance with at least some embodiments of the present disclosure. The processing chamber 100 generally includes a chamber body 104 having a sidewall 103, a bottom 105, and a lid assembly 106, the chamber body enclosing an interior volume 108. A substrate support 102 is at least partially disposed in the interior volume 108 and can support a substrate 110 that has been transferred to the interior volume 108 through a port 112 formed in the chamber body 104. A process kit 124 is disposed in the interior volume 108 and includes a rinse ring 116 disposed about the substrate 110 when the substrate 110 is present. In some embodiments, the process kit 124 includes a shadow ring 182 disposed on the rinse ring 116.

[0021] The interior volume 108 can be selectively fluidly connected to a vacuum system 130 to control the pressure therein. The showerhead assembly 128 can be coupled to a process gas source 132 to provide process gas to the interior volume 108 for depositing material onto the substrate 110. The showerhead assembly 128 can also include a temperature control element 134 for controlling the temperature of the showerhead assembly 128. The temperature control element 134 can be a fluid channel in fluid communication with a coolant source 136.

[0022] The substrate support 102 includes an upper support assembly 113, such as a pedestal 114. In some embodiments, the pedestal 114 includes a thermal element 120. The pedestal 114 includes a support surface 118 that is adapted to contact (or be in proximity to) a major surface of the substrate 110 during processing. Thus, the pedestal 114 serves as a primary support structure for the substrate 110 in the processing chamber 100. The pedestal 114 may be made of a conductive material and serves as a ground path for RF power from the power element 140B distributed through the showerhead assembly 128. Thus, the processing chamber 100 may perform a deposition or etching process utilizing an RF or DC plasma.

[0023] The pedestal 114 may include a thermal element 120 for controlling the temperature of the substrate 110 during processing. The thermal element 120 may be, for example, a heater or cooler positioned atop or within the pedestal 114. The heater or cooler may be a separate component that is coupled to the top of the pedestal 114 or may be an integral part of the pedestal 114. For example, in some embodiments, the pedestal 114 includes a heater plate in which the thermal element 120 is disposed. In some embodiments, the thermal element 120 includes one or more resistive heating elements.

[0024] In some embodiments, the thermal element 120 is embedded in the base body (eg, Figure 1 10). In some embodiments, the embedded thermal element 120 can be a heating or cooling element or channel for applying thermal energy absorbed by the substrate 110 to the body of the base 114. Other elements can be disposed on or embedded in the base 114, such as one or more electrodes, sensors, and / or vacuum ports for vacuum clamping. The temperature of the substrate 110 can be monitored by one or more sensors (not shown). The embedded thermal element 120 can be a controlled zone so that the temperature at different areas of the body of the base 114 can be independently heated or cooled.

[0025] The pedestal 114 may be coupled to an actuator 126 via a shaft 121 that provides one or more of vertical motion (on the z-axis), rotational motion (about axis A), and may also provide angular movement (relative to axis A). Vertical motion may be provided by the actuator 126 to allow transfer of the substrate 110 between the flush ring 116 and the support surface 118. The shaft 121 passes through the bottom 105 of the processing chamber 100 via an opening 127. An isolated processing environment may be maintained by a bellows 154 surrounding the opening 127 and connected to a portion of the shaft 121.

[0026] The flush ring 116 may circumscribe (i.e., surround) the pedestal 114 such that the lower surface of the substrate 110 will be supported by the pedestal 114. In some embodiments, the flush ring 116 is illustrated as being supported by a peripheral shoulder 122 formed around the circumference of the pedestal 114. Those skilled in the art will appreciate that the illustrated embodiment represents only one possible configuration and should not be viewed as limiting the scope of the present disclosure.

[0027] The substrate 110 may be brought into the interior volume 108 by the robot 109 through a port 112 in the side wall 103 of the processing chamber 100. The port 112 may be, for example, a slit valve. The lift pins 152 may pass through openings in the body of the pedestal 114 and the thermal element 120. When not in use, the lift pins 152 may be lowered out of position during processing. The lift pins 152 may 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 remains aligned with the opening in the pedestal 114. Figure 1 As shown, the lift pins 152 are lowered, which lowers the substrate 110 onto the support surface 118 adjacent the flush ring 116 .

[0028] In some embodiments, a flushing line 162 may extend from a flushing gas source 164 to an upper surface 180 of the pedestal 114. The flushing line 162 is configured to flow a flushing gas through a gap between the flushing ring 116 and the substrate 110. In some embodiments, the substrate 110 may be retained via a vacuum chuck. For example, the pump 150 may be coupled to a vacuum line 168 that extends from the pump 150 to the support surface 118 to vacuum clamp the substrate 110 against the support surface 118. The flushing gas may be any suitable inert gas, such as argon, nitrogen, or the like. In some embodiments, the pedestal 114 may be an electrostatic chuck and the pedestal 114 may include one or more electrodes 125 (e.g., Figure 1 ). For example, the base 114 may be coupled to a power element 140A, which may be a voltage source that provides power to one or more electrodes 125. The voltage source may be a radio frequency (RF) controller or a direct current (DC) controller.

[0029] Figure 2A schematic cross-sectional view of a portion of a substrate support 102 and a process kit 124 is depicted in accordance with at least some embodiments of the present disclosure. The substrate support 102 includes a pedestal 114 having one or more purge gas inlets 206 for flowing purge gas through a purge line 162. The purge ring 116 generally includes an annular body disposed radially outward from the one or more purge gas inlets 206 on a peripheral shoulder 122 of the pedestal 114. The purge ring 116 includes an inner portion 220 and an outer portion 222. In some embodiments, the inner portion 222 has an upper inner recess 224 defining a first inner sidewall 228 and an inner upper wall 226 of the annular body. In some embodiments, the inner upper wall 226 of the annular body extends horizontally. In some embodiments, a shadow ring 182 is disposed on the purge ring 116 and extends above the upper inner recess 224. In some embodiments, the flush ring 116 includes a plurality of openings 237 configured to receive the alignment pins 211 of the shadow ring 182 to align the shadow ring 182 with the flush ring 116 .

[0030] In some embodiments, the interior 222 has a lower inner recess 232 defining a second inner sidewall 234 and an inner lower wall 236 of the annular body. In some embodiments, the third inner sidewall 204 is disposed between the first inner sidewall 228 and the second inner sidewall 234. In some embodiments, the third inner sidewall 204 is disposed radially inward from the first inner sidewall 228 and the second inner sidewall 234. In some embodiments, the first height 216 of the first inner sidewall 228 is less than the second height 219 of the second inner sidewall 234. In some embodiments, the first height 216 is less than the third height 231 of the third inner sidewall 204. In some embodiments, the third height 231 is greater than the second height 219 and the first height 216. In some embodiments, the inner upper wall 226 extends horizontally from the third inner sidewall 204 to the first inner sidewall 228.

[0031] The pedestal 114 and the flushing ring 116 together define a gas flow path between the pedestal 114 and the inner lower wall 236, the third inner sidewall 204, and the inner upper wall 226 of the flushing ring 116. In some embodiments, the pedestal 114 includes a second shoulder 181 disposed radially inwardly from the peripheral shoulder 122 and elevated. In some embodiments, the first gap 242 between the inner lower wall 236 and the second shoulder 181 is about 0.01 to about 0.06 inches. In some embodiments, the second gap 244 between the third inner sidewall 204 and the opposing outer surface 253 of the pedestal 114 is about 0.01 to about 0.04 inches. In some embodiments, the third gap 246 between the inner upper wall 226 and the substrate 110 is about 0.01 to about 0.04 inches.

[0032] Adjusting the size of the first gap 242, the second gap 244, and the third gap 246 advantageously establishes a high velocity edge flush flow across the lower surface of the substrate 110, thereby preventing front side gas from above the substrate 110 from diffusing to the lower surface of the substrate, which gas diffusion may result in unwanted deposition. In some embodiments, the gas flow path is further defined between the inner upper wall 226 and the bottom surface 217 of the shadow ring 182 and between the bottom surface 217 and the upper surface of the substrate 110. In some embodiments, the fourth gap 218 between the bottom surface 217 and the upper surface of the substrate 110 is about 4 mils to about 10 mils, for example, about 4 mils to about 6 mils.

[0033] Figure 3 Depicted is an isometric view of a flush ring in accordance with at least some embodiments of the present disclosure. Figure 4 A bottom view of a flush ring according to at least some embodiments of the present disclosure is depicted. The flush ring 116 generally includes an annular body having a central opening 310. In some embodiments, the central opening 310 has a diameter of about 10 inches to about 13 inches. The outer diameter of the annular body can be about 12 to about 15 inches. In some embodiments, the upper surface 306 of the annular body is substantially flat. In some embodiments, the annular body includes a plurality of protrusions 402 for aligning the annular body to a first chamber component. In some embodiments, the first chamber component can be a base 114. The plurality of protrusions 402 can be disposed on a lower surface 420 of the flush ring 116. In some embodiments, the upper surface 306 can include a plurality of recesses 312 that align with the plurality of protrusions 402 on the lower surface 420. Each of the plurality of recesses 312 can include an opening 404 extending from a lower surface of the plurality of recesses 312 to the lower surface 420. The opening 404 can be used to couple the flush ring 116 to the first chamber component.

[0034] In some embodiments, the flush ring 116 includes a plurality of openings 308 for aligning the annular body to a second chamber component. In some embodiments, the second chamber component is a shield ring 182. In some embodiments, the plurality of openings 308 may include a first opening 308A having a first size and a second opening 308B having a second size. In some embodiments, the first size is different from the second size. For example, the first size includes a diameter that is smaller than the diameter of the second size.

[0035] Figure 5Depicted is a cross-sectional view of the flushing ring 116 taken along an axis extending through one of the plurality of recesses 312, in accordance with at least some embodiments of the present disclosure. In some embodiments, the plurality of recesses 312 define a horizontal surface 510 and an angled surface 512 extending downwardly and radially outwardly from the horizontal surface 510. In some embodiments, the lower inner recess 238 defines an inner lower wall 236 having a first portion 532 and a second portion 536, wherein the second portion 536 extends along a horizontal plane different from the horizontal plane along which the first portion 532 extends. In some embodiments, the second portion 536 is disposed closer to the upper surface 306 of the annular body than the first portion 532. In some embodiments, a step 534 between the first portion 532 and the second portion 536 is disposed radially outwardly from the first inner surface 228.

[0036] In some embodiments, the lower inner recess 238 includes a rounded sidewall 550 between the inner lower wall 236 and the second inner sidewall 234. In some embodiments, the third height 231 between the upper inner recess 224 and the lower inner recess 238 is greater than the first height 216 and less than the second height 219. In some embodiments, the first height is about 0.3 to about 0.6 inches. In some embodiments, the third height 231 is about 0.06 to about 0.12 inches. In some embodiments, the third inner sidewall 204 includes an upper portion 551 and a lower portion 552 extending radially outward and downward from the upper portion 551.

[0037] Figure 6 A cross-sectional view of the flush ring 116 taken along an axis extending through the plurality of openings 308 is depicted in accordance with at least some embodiments of the present disclosure. The plurality of openings 308 may include two diametrically opposed openings. In some embodiments, the plurality of openings 308 have angled sidewalls 610 to receive the alignment pins 211 of the shield ring 182.

[0038] Figure 7 Depicted is an isometric view of a flush ring in accordance with at least some embodiments of the present disclosure. Figure 8 A bottom view of a flush ring according to at least some embodiments of the present disclosure is depicted. In some embodiments, the plurality of openings 308 for aligning the flush ring 116 with the shield ring 182 includes three openings. In some embodiments, the plurality of openings 308 are of equal size and are symmetrically disposed about the flush ring 116 axis. The plurality of openings 308 may be circular, oval, or any other suitable shape. In some embodiments, the outer portion 222 of the flush ring 116 includes outer legs 708 extending from a lower surface 802 of the outer portion 222. In some embodiments, a plurality of protrusions 810 for aligning the annular body of the flush ring 116 to the first chamber component extend from the lower surface 802.

[0039] Fig. 91 depicts a cross-sectional view of a flush ring 116 in accordance with at least some embodiments of the present disclosure. In some embodiments, the outer leg 708 has a height 902 that is greater than the sum of the first height 216, the second height 219, and the third height 231. In some embodiments, the height 902 is about 0.9 to about 1.3 inches. In some embodiments, a lower surface 910 of the outer leg 708 is rounded. In some embodiments, the outer surface of the outer leg 708 is coplanar with the outer surface of the outer portion 222.

[0040] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.

Claims

1. A flush ring for use in a processing chamber, comprising: An annular body having an interior and an exterior, wherein the interior comprises an inner surface of the annular body, the inner surface including a first inner sidewall, a second inner sidewall, and a third inner sidewall, wherein the interior has an upper inner recess defining the first inner sidewall and a lower inner recess defining the second inner sidewall, wherein the third inner sidewall is disposed between the first inner sidewall and the second inner sidewall, and wherein the first inner sidewall and the second inner sidewall are disposed radially outward from the third inner sidewall.

2. The flush ring of claim 1, wherein a lower surface of the annular body includes a plurality of protrusions for aligning the annular body to a chamber component.

3. The flush ring of claim 2, wherein the outer portion includes a plurality of openings for aligning the annular body to a second chamber component. The flush ring of claim 1 , wherein a first height of the first inner sidewall is less than a second height of the second inner sidewall. 5 . The flush ring of claim 4 , wherein a third height between the upper inner recess and the lower inner recess is greater than the first height and less than the second height.

6. The flush ring of any one of claims 1 to 4, wherein the outer portion includes outer feet extending from a lower surface of the outer portion.

7. The flush ring of any one of claims 1 to 4, wherein the lower inner recess comprises rounded side walls.

8. The flush ring of any one of claims 1 to 4, wherein the first height of the first inner sidewall is about 0.3 to about 0.6 inches.

9. The flushing ring according to any one of claims 1 to 4, wherein the lower inner recess defines an inner lower wall having a first portion and a second portion, wherein the second portion is disposed closer to an upper surface of the annular body than the first portion.

10. A processing kit for use in a processing chamber, comprising: The flushing ring according to any one of claims 1 to 4, wherein the inner upper wall of the annular body extends horizontally.

11. The processing kit according to claim 10, wherein: The outer portion includes outer legs extending from a lower surface of the outer portion, or The lower inner recess defines an upper surface having a first portion and a second portion, wherein the second portion extends along a horizontal plane different from a horizontal plane along which the first portion extends.

12. The process kit of claim 10, wherein an upper surface of the annular body is substantially flat.

13. The process kit of claim 10, wherein a lower surface of the annular body comprises a plurality of protrusions for aligning the annular body to a chamber component and a plurality of openings for aligning the annular body to a second chamber component.

14. The process kit of claim 10, further comprising a shield ring disposed on the rinse ring and extending over the upper inner recess.

15. A substrate support, comprising: a susceptor configured to support a substrate and having one or more purge gas inlets; and A flushing ring according to any one of claims 1 to 4, arranged on a peripheral shoulder of the base radially outwardly from the one or more flushing gas inlets, wherein the base and the flushing ring together define a gas flow path along the inner lower wall, the third inner side wall and the inner upper wall of the annular body.

16. The substrate support of claim 15, wherein a gap between the third inner side wall and the outer surface of the pedestal is about 0.01 to about 0.04 inches, and a gap between the inner lower wall and the pedestal is about 0.01 to about 0.04 inches.

17. The substrate support of claim 15, wherein the inner upper wall of the annular body extends horizontally.

18. The substrate support of claim 15, wherein the pedestal comprises a heater plate having one or more resistive heating elements disposed therein.

19. The substrate support of claim 15, further comprising: A shield ring is disposed on the flush ring and extends above the upper inner recess.

20. The substrate support of claim 19, wherein the flush ring comprises a plurality of openings configured to receive alignment pins of the shadow ring to align the shadow ring with the flush ring.

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