High frequency grounding system and method

Abstract

The present disclosure provides an apparatus including a chamber body and a lid defining an interior space. The apparatus includes a substrate support disposed on the opposite side of the lid within the space. The substrate support includes a support body disposed on a stem and a ground plate disposed between the support body and the stem. An upper flange is coupled to a lower peripheral surface of the ground plate, and a lower flange is coupled to a lower portion of the chamber body. The lower and upper flanges are coupled to each other with a plurality of straps, each of the plurality of straps having a first end coupled to the lower flange and a second end coupled to the upper flange.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure generally relate to systems and methods for manufacturing semiconductor devices. In particular, the present disclosure is directed to systems and methods for providing a high frequency ground path. [Background technology]

[0002]

[0002] Plasma-enhanced chemical vapor deposition (PECVD) is a process used to deposit films on substrates, such as semiconductor substrates. CVD is achieved by introducing process gases into a process chamber that contains the substrate. The process gases are directed into a process space within the process chamber through a gas distribution assembly.

[0003] Radio frequency (RF) power is used to excite process gases in a process chamber to generate a plasma. The RF power returns to the source. In some cases, arcing can result from the RF power in the process chamber, damaging the chamber and its components. Ground paths are provided to direct the RF power away from the process chamber components to prevent damage thereto and attempt to reduce the occurrence of arcing within the process chamber. However, current ground path designs are complex, expensive, require significant maintenance over time, and do not fully address arcing within the process chamber.

[0004]

[0004] Therefore, there is a need for a simpler, cheaper, lower maintenance, and more effective RF return path design. Summary of the Invention

[0005] In some embodiments, an apparatus is provided that includes a chamber body and a lid that define an interior space. The apparatus includes a substrate support disposed on an opposite side of the lid within the space. The substrate support includes a support body disposed on a stem and a ground plate disposed between the support body and the stem. An upper flange is coupled to a lower peripheral surface of the ground plate, and a lower flange is coupled to a lower portion of the chamber body. The lower flange and the upper flange are coupled to each other with a plurality of straps, each of the plurality of straps having a first end coupled to the lower flange and a second end coupled to the upper flange.

[0006] In some embodiments, a method for processing a substrate is provided. The method includes placing a substrate on a substrate support within a volume of a processing chamber. The substrate support is positioned opposite a lid within the volume. The substrate support includes a support body disposed on a stem, a ground plate disposed between the support and the stem, and an upper flange coupled to a lower peripheral surface of the ground plate. The processing chamber includes a lower flange coupled to a lower portion of the chamber volume and a plurality of straps. Each of the plurality of straps has a first end coupled to the lower flange and a second end coupled to the upper flange. The substrate support is raised to a raised position to form an upper portion of the volume. The method includes introducing a gas into the upper portion of the volume and exciting the gas using radio frequency waves.

[0007]

[0007] In some embodiments, a grounding assembly is provided that includes an upper flange having an upper flange upper surface and an upper flange lower surface. The grounding assembly includes a lower flange having a lower flange upper surface and a lower flange lower surface. The lower flange has a lower portion extending radially inward from an inner diameter of the lower flange, the lower portion having one or more apertures configured to receive screws. The grounding assembly includes a plurality of straps. Each of the plurality of straps includes a first end coupled to the lower flange and a second end coupled to the upper flange.

[0008]

[0008] So that the features of the present disclosure described above may be understood in detail, a more particular description of the present disclosure briefly summarized above may be had by reference to embodiments, some of which are illustrated in the accompanying drawings. However, since the present disclosure may admit of other equally effective embodiments, it should be noted that the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure. [Brief explanation of the drawings]

[0009] [Figure 1]

[0009] FIG. 1 depicts a schematic diagram of a processing chamber according to an exemplary embodiment of the present disclosure. [Figure 2A]

[0010] 1 depicts a ground contact assembly in a lowered position according to an exemplary embodiment of the present disclosure. [Figure 2B]

[0011] 1 depicts a grounding assembly in a raised position according to an exemplary embodiment of the present disclosure. [Figure 2C]

[0012] 1 depicts a grounding assembly and fixture prior to installation according to an exemplary embodiment of the present disclosure. [Figure 3A]

[0013] 1 depicts a top view of an exemplary lower flange of a grounding assembly according to an exemplary embodiment of the present disclosure. [Figure 3B]

[0014] 1 depicts a cross-sectional view of a lower flange according to an exemplary embodiment of the present disclosure. [Figure 4A]

[0015] 1 depicts a top view of an exemplary strap of a grounding assembly according to an exemplary embodiment of the present disclosure. [Figure 4B]

[0016] 1 depicts the end of a strap secured within a lower flange of a grounding assembly according to an exemplary embodiment of the present disclosure. [Figure 5A]

[0017] 1 depicts a bottom view of an exemplary upper flange of a grounding assembly according to an exemplary embodiment of the present disclosure. [Figure 5B]

[0018] 1 depicts a top view of an exemplary upper flange of a grounding assembly according to an exemplary embodiment of the present disclosure. [Figure 6]

[0019] 1 depicts a flow diagram of an exemplary method for processing a substrate according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0020] For ease of understanding, wherever possible, like reference numerals have been used to designate like elements common to the figures. It is believed that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011]

[0021] Several embodiments presented herein are directed to radio frequency (RF) grounding within a process chamber. The process chamber includes a chamber body and a lid that define an interior space. A substrate support is disposed within the space opposite the lid and is coupled to a grounding assembly. The substrate support includes a support body disposed on a stem. The grounding assembly is coupled to a ground plate disposed between the support body and the stem. An upper flange is coupled to a lower peripheral surface of the ground plate, and a lower flange is coupled to a lower portion of the chamber body. The upper and lower flanges are coupled to each other by metal straps. Each of a plurality of straps is coupled to the lower flange at a first end and to the upper flange at a second end.

[0012]

[0022] FIG. 1 depicts a schematic diagram of a processing chamber 100 according to an exemplary embodiment of the present disclosure. The process chamber 100 includes a chamber body 102 and a lid assembly 104 disposed on the chamber body 102. The chamber body 102 and the lid assembly 104 define an interior upper space 110 and a lower space 111. A lower portion 148 of the chamber body 102 faces the lid assembly 104. The lid assembly 104 includes a face plate 106 having a plurality of holes 134 for supplying gas from a gas source 130 coupled to the lid 104. The plurality of holes 134 are formed through the face plate 106. Gas from the gas source 130 flows into a plenum 132 defined at least in part by the lid 104 and the face plate 106. The plenum 132 is in fluid communication with the upper space 110 via the plurality of holes 134. A plurality of holes 134 formed through the face plate 106 allow for a substantially uniform distribution of gas within the upper volume 110. A power source 170, such as an RF power source, is coupled to the support body 112 and is used to excite gas from the gas source 130 within the upper volume 110.

[0013]

[0023] A channel 124 is formed through the lid 104. The channel 124 surrounds at least a portion of the upper space 110. The channel 124 is in fluid communication with an exhaust pump (not shown). The channel 124 allows gases and particles to be removed from the upper space 110 to prevent damaging or contaminating a film on the substrate. It is contemplated that in some embodiments, the channel 124 may instead be formed in a sidewall of the chamber body 102.

[0014]

[0024] An opening 126 is formed through the chamber body 102 to allow a substrate to be loaded through the opening 126 onto a support surface 150 of the substrate support 105. The support surface 150 is substantially parallel to and faces the lid assembly 104.

[0015]

[0025] The substrate support 105 is disposed within the process chamber 100. The substrate support 105 includes a support body 112, an insulating plate 122, a grounded plate 146, and a stem 108. The insulating plate 122 is disposed between the support body 112 and the grounded plate 146, and both plates are disposed on the stem 108. The insulating plate 122 is fabricated from an electrically insulating material, such as a dielectric material such as silicon oxide or aluminum oxide, or a ceramic, to electrically insulate the support body 112 from the grounded plate 146. The support body 112 may be a chuck, such as an electrostatic chuck or a vacuum chuck, and includes a lower surface 156 facing the lower portion 148 of the chamber body 102. In some embodiments, which can be combined with other embodiments described herein, the support body 112 is a single member. The stem 108 extends laterally through the lower portion 148 of the chamber body 102. The stem 108 is substantially perpendicular to the lower portion 148. The lower portion 148 is substantially parallel to the face plate 106. The conductive rod 114 is disposed within and extends through the stem 108 and is electrically coupled to the ground plate 146.

[0016]

[0026] The ground plate 146 is coupled to a ground assembly 160. The ground assembly 160 is coupled to the support body 112 via the ground plate 146 and an insulating plate 122. The ground plate 146 is fabricated from a conductive material (e.g., a metal such as aluminum) and is coupled to the insulating plate 122. The insulating plate 122 is coupled to a lower surface 156 of the support body 112. Alternatively, the ground plate 146 and the insulating plate 122 include a central opening in which the stem 108 is disposed, allowing contact between the stem 108 and a central portion of the lower surface 156. The support body divides the interior of the process chamber 100, including an upper (or process) space 110 and a lower space 111. An actuator 116 moves the substrate support 105 between an upper or raised processing position and a lower loading position.

[0017]

[0027] A grounding assembly 160 including a plurality of straps 121 physically and electrically couples the grounding plate 146 to the chamber body lower portion 148. The grounding assembly 160 includes an upper flange 118, a lower flange 119, and a plurality of straps 121 (e.g., flexible straps) extending therebetween. An RF return path is provided from the RF source 170 to the support body 112, through the plasma in the upper volume 110, down along the chamber wall to the chamber lower portion 148, up the straps 121 to the grounding plate 146, to the upper flange 118, to the grounding plate 146, and via the conductive rod 114 to ground.

[0018]

[0028] The upper flange 118 of the grounding assembly 160 is disposed along the lower peripheral surface 142 of the grounding plate 146 and is fastened or bonded thereto using fasteners, welding, brazing, or conductive paste. The upper flange 118 is disposed in a plane substantially parallel to the support surface 150. The upper flange 118 extends along the lower surface 142 of the grounding plate 146 and is aligned with the radially outer surface 144 of the support body 112. The upper flange 118 is ring-shaped and fabricated from a conductive material, such as a metal, such as aluminum or steel, including stainless steel. The upper flange 118 is electrically coupled to the lower flange 119 via a plurality of straps 121. The upper flange 118 is configured to move with the substrate support body 112 between a lowered position and a raised position when the actuator 116 lowers and raises the support body 112. During actuation, the straps 121 flex, for example, inward, to accommodate movement of the support body 112.

[0019]

[0029] The lower flange 119 is coupled to the lower portion 148 of the chamber body. The lower flange 119 is a ring axially aligned with the upper flange 118. The upper flange has an outer diameter substantially equal to the outer diameter of the support surface 150, which is substantially equal to the outer diameter of the lower flange 119. In one embodiment, the lower flange 119 and the upper flange 118 have the same dimensions. The lower flange 119 is fabricated from a conductive material, such as a metal, such as aluminum or stainless steel. The lower flange 119 is fixed in place during movement of the support body 112. The lower flange 119 facilitates the flow of RF current away from the RF source. An RF current path is provided from the RF source 170 to the support body 112, through the plasma in the upper volume 110, down along the chamber wall to the lower chamber portion 148, up the strap 121 to the ground plate 146, to the upper flange 118, to the ground plate 146, and via the conductive rod 114 to ground.

[0020]

[0030] FIG. 2A depicts grounding assembly 160 in a lowered, e.g., compressed, position, and FIG. 2B depicts grounding assembly 160 in a raised, e.g., extended, position. In the lowered position, straps 121 are compressed radially inward as depicted in FIG. 2A. In the raised position, straps 121 are extended as depicted in FIG. 2B. In the lowered position, the gap between the lower surface of upper flange 118 and the upper surface of lower flange 119 is large enough so that the threads on upper flange 118 do not contact the threads on lower flange 119.

[0021]

[0031] FIG. 2C depicts the grounding assembly 160 prior to installation into the process chamber 100. The grounding assembly 160 is in a compressed position, with a fixture 202 positioned between the upper flange 118 and the lower flange 119. While FIG. 2C depicts a single fixture 202, there may be more than one fixture 202 positioned between the upper flange 118 and the lower flange 119. In some embodiments, which may be combined with other embodiments described herein, there may be about one to about six fixtures, e.g., about two to about four fixtures, e.g., about three fixtures. The fixture 202 is secured in place between the upper flange 118 and the lower flange 119 by a screw 204, such as a stainless steel screw. The screw extends from the top of the upper flange 118, through the fixture 202, and partially through the upper portion of the lower flange 119. The screw 204 is removed, and during installation, the grounding assembly 160 is placed in place in the chamber using the fixture 202. Once the top plate 118 is secured to the ground plate 146 , the fixture 202 is removed from the side between the top flange 118 and the bottom flange 119 .

[0022]

[0032] FIG. 3A depicts a top view of the lower flange 119, showing the upper surface 317 of the lower flange 119, and FIG. 3B depicts an L-shaped cross-section of the lower flange 119. The lower flange 119 is a ring having an L-shaped cross-section as shown in FIGS. 3A and 3B. A first width 312 of an upper portion 324 of the lower flange 119, including the upper surface 317, is defined by an outer circumferential edge 305 and a first inner circumferential edge 303, each having a concentrically aligned surface. The first width 312 is about 20 mm to about 30 mm, for example, about 25 mm. A second width 314 of a lower portion 322 of the lower flange 119, including the lower surface 319 of the lower flange 119, is defined by the outer circumferential edge 305 and a second inner circumferential edge 306, each having a concentrically aligned surface. The second width 314 is about 30 mm to about 40 mm, for example about 35 mm. The second width 314 can be about 5% to about 30% wider than the first width 312, for example about 5% to about 25%, for example about 10% to about 20% wider.

[0023]

[0033] The lower portion 322 of the lower flange 119 has a first surface (e.g., lower surface 319 of the lower flange) and a second surface 318, where the second surface 318 is disposed parallel to the first surface 319 of the lower portion 322 of the lower flange 119. The height 332 of the lower portion 322 of the lower flange 119 is the distance between the first surface 319 and the second surface 318 of the lower portion 322 of the lower flange 119. The height 332 of the lower portion 322 of the lower flange 119 is about 4 mm to about 6 mm, for example, about 4 mm to about 5 mm. The overall height 334 of the lower flange 119 is the distance between the first surface 319 and the upper surface 317 of the lower flange 119. The overall height 334 of the lower flange 119 is about 20 mm to about 50 mm, for example, about 30 mm to about 45 mm, for example, about 43 mm. The height 332 of the lower portion 322 is about 2% to about 30%, for example, about 4% to about 20%, for example, about 5% to 15% of the overall height 334 of the lower flange 119. The height 332 of the lower flange 119 is selected based on the space available in the chamber to install the grounding assembly 160 and to allow for, for example, removal of the fixture 202. The outer diameter of the lower flange 119 is sized to be substantially the same as the outer diameter of the support body 112 and the outer diameter of the upper flange 118. In some embodiments, which may be combined with other embodiments described herein, the outer diameter of one or both of the lower flange 119 and the upper flange 118 is about 300 mm to about 400 mm, for example, about 350 mm to about 370 mm.

[0024]

[0034] The second surface 318 of the lower portion 322 of the lower flange 119 includes a plurality of apertures 308 (four shown) disposed therethrough. The plurality of apertures 308 are configured to receive fasteners 416 (FIG. 4B) to couple the lower flange 119 to the chamber body lower portion 148. In one example, each aperture 308 of the plurality of apertures 308 is disposed at an equal angular distance from one another. For example, when four apertures 308 are utilized, the apertures 308 are spaced approximately 90 degrees apart from one another. In some embodiments, which may be combined with other embodiments described herein, the angular spacing between each of the apertures 308 around the lower flange is between approximately 18 degrees and approximately 36 degrees, e.g., approximately 30 degrees. The apertures 308 are staggered with one or more lift pin standoffs such that the strap 121 does not come into physical contact with the lift pin standoffs. The apertures 308 are staggered with current-providing holes in the chamber.

[0025]

[0035] The upper surface 317 of the lower flange 119 includes a plurality of recesses 302 formed therein. Each recess 302 extends from the outer edge 305 of the lower flange 119 to the radially inward edge 303 of the upper portion 324. The distance from the inward edge 303 to the outer edge 305 is about 20 mm to about 30 mm, such as about 25 mm. Each recess 302 is configured to receive a first end 410 of each strap 121 (see FIG. 4) and may extend to a depth equal to the thickness of each strap 121. An exemplary strap 121 is depicted in FIG. 4A. The strap 121 includes a first end 410, a second end 412, and at least one aperture 414 disposed in each of the first and second ends 410, 412. During installation, the first end 410 is disposed within the recess 302 in the upper surface 317 of the lower flange 119. Apertures 414 align with apertures 304 formed in recesses 302. First ends 410 of straps 121 are secured within recesses 302 with fasteners 416, as shown in FIG. 4B . In some embodiments, which may be combined with other embodiments described herein, first ends 410 of straps 121 are secured to upper surface 317 of lower flange 119 by welding or brazing. Each recess 302 is angularly offset from apertures 308, such that apertures 304 are also angularly offset from apertures 308. In one example, each recess 302 is angularly equidistant from adjacent apertures 308. The number of apertures 304 is equal to the number of apertures 308 in FIG. 3A , although it is contemplated that the number of apertures 304 may be greater or less than the number of apertures 308.

[0026]

[0036] FIG. 5A depicts a bottom view of the upper flange 118, showing the underside 527 of the upper flange 118. The underside 527 of the upper flange 118 is defined by an outer circumferential edge 525 and an inner circumferential edge 523, each edge having a concentrically aligned surface. The distance from the outer circumferential edge 525 to the inner circumferential edge 523 is about 15 mm to about 30 mm, for example, about 20 mm to about 25 mm. A plurality of recesses 522 are disposed on the underside 527 of the upper flange 118. The recesses 522 on the underside 527 of the upper flange 118 align with the recesses 302 on the upper surface 317 of the lower flange 119. The second end 412 of the strap 121 (shown in FIG. 4A) is coupled to the underside 527 of the upper flange 118 in substantially the same manner as the first end 410 is secured to the upper surface 317 of the lower flange 119. In particular, strap 121 is secured by placing second end 412 within recess 522 disposed in upper flange 118, aligning aperture 524 in second end 412 of strap 121 with aperture 524 disposed within recess 522 in undersurface 527 of upper flange 118, and securing second end 412 of strap 121 with fastener 416. In some embodiments, which may be combined with other embodiments described herein, second end 412 of strap 121 is secured to undersurface 527 of upper flange 118 by welding or brazing.

[0027]

[0037] The underside 527 of the upper flange 118 includes a plurality of apertures 508 (four shown) disposed therethrough. The plurality of apertures 508 are configured to receive fasteners 416 to couple the upper flange 118 to the ground plate 142. Additionally, at least one of the plurality of apertures 508 is used to secure the fixture 202 to the upper flange using a screw 204. In some embodiments that may be combined with other embodiments disclosed herein, each aperture 508 of the plurality of apertures 508 is disposed at an equal angular distance from one another. In some embodiments that may be combined with other embodiments disclosed herein, each recess 522 is angularly equidistant from an adjacent aperture 508. The number of apertures 524 is equal to the number of apertures 508 in FIG. 5A , although it is contemplated that the number of apertures 524 may be greater or less than the number of apertures 508. While Figures 3A and 5A each depict four recesses (e.g., 302, 522), an exemplary grounding assembly 160 may have four or more straps 121, such as from about 10 to about 20, e.g., from about 10 to about 16, e.g., about 12.

[0028]

[0038] 5B illustrates a top view of the upper flange 118 showing the upper surface 502 of the upper flange 118. The upper surface 502 of the upper flange 118 includes a channel 528 disposed about the upper surface 502 that separates an outer portion 532 of the upper flange 118 from an inner portion 530 of the upper flange 118. The channel 528 is configured to receive a gasket, such as a stainless steel gasket, to seal the upper flange 118 to the ground plate 142. Sealing the upper flange 118 prevents RF current from leaking into the lower space 111. A plurality of apertures 508 are disposed about the outer portion 532, and a plurality of apertures 524 are disposed about the inner portion 530. The apertures 524 are configured to receive the straps 121.

[0029]

[0039] The fasteners 416 are any suitable screws, such as high-nickel stainless steel screws. The screws are made of a conductive material, such as an alloy, such as steel. In some embodiments that may be combined with other embodiments disclosed herein, the screws do not contain copper. The straps 121 are made of a conductive material, such as an alloy, such as steel. The straps 121 may be made of a material containing carbon, chromium, nickel, manganese, silicon, nitrogen, phosphorus, sulfur, stainless steel, Inconel material, alloys thereof, or combinations thereof. The multiple straps 121 are symmetrically arranged around each of the upper and lower flanges, as depicted in the grounding assembly 160, to provide a symmetrical RF return path within the process chamber. It has been discovered that if the straps 121 are not properly symmetrical, process uniformity and device quality are affected. In some embodiments that may be combined with other embodiments described herein, the angular spacing between each of the multiple straps 121 around the lower flange is about 18 degrees to about 36 degrees, for example, about 30 degrees. In some embodiments, which may be combined with other embodiments described herein, the angular spacing between two adjacent straps 121 varies by less than 5% relative to the remaining adjacent straps 121. The straps 121 are staggered with one or more lift pin standoffs such that the straps 121 do not come into physical contact with the lift pin standoffs.

[0030]

[0040] The thickness of each strap 121 is about 0.12 mm to about 0.30 mm, e.g., about 0.15 mm to about 0.2 mm. The length of the strap 121 is about 180 mm to about 195 mm, e.g., about 180 mm to about 190 mm, e.g., about 195 mm. The width of the strap 121 is about 8 mm to about 15 mm, e.g., about 9 mm to about 11 mm, e.g., about 10 mm. The strap 121 has a spring constant of greater than about 17 lb / in, such as about 17 lb / in to about 20 lb / in, e.g., about 18 lb / in to about 19 lb / in, e.g., about 18.4 lb / in to about 18.8 lb / in. Each strap is constructed of stainless steel, such as SS302 or Inconel material. In some embodiments, which may be combined with other embodiments described herein, the material of the strap is any material that provides a sufficient spring constant and corrosion resistance. In some embodiments, which may be combined with other embodiments described herein, the strap is mechanically cycled by bending the strap approximately 200,000 to 2 million times without evidence of mechanical failure.

[0031]

[0041] The grounding assembly 160 used herein can be used for multiple runs without replacing the strap 121. In contrast, conventional grounding assemblies are typically replaced or serviced periodically due to a loss of spring constant over time. These grounding assemblies include designs with grounding components that are always coupled only to the grounding plate during processing. Furthermore, the grounding components contact the substrate lid seal only when the support body 112 is in a raised position during processing. During processing with these conventional grounding assemblies, the support body 112 is repeatedly raised and lowered, which relies on multiple compressions and expansions of the grounding components. These multiple compressions and expansions of the grounding components result in a reduction in resilience or spring constant over time due to overuse, and the grounding components are periodically replaced. In contrast, the grounding assembly 160 described herein is always coupled to the grounding plate and always coupled to the bottom of the chamber during operation. Therefore, raising and lowering the support body 112 does not reduce the contact of the grounding assembly 160 with the chamber body. Furthermore, because the straps 121 of the present disclosure are fastened at each end to the upper and lower flanges 118, 119, the straps 121 do not rely on an inherent spring constant to return to their original shape. Rather, actuation of the substrate support 105 returns the straps 121 to a desired position. Thus, the problem of spring constant degradation that is plaguing conventional approaches is addressed by the present disclosure.

[0032]

[0042] 6 depicts a flow diagram of an exemplary method 600 for processing a substrate, according to an exemplary embodiment of the present disclosure. In operation 602, a substrate is placed on a substrate support 105 in the upper space 110 of the processing chamber 100. The substrate is loaded onto a support surface 150 of the substrate support 105 (e.g., a pedestal) through an opening 126 formed through the chamber body 102. The substrate support 105 is coupled to an exemplary grounding assembly 160 via a ground plate 146 described herein. Placing the substrate on the substrate support includes placing the substrate on the support body 112.

[0033]

[0043] In operation 604 of method 600, the substrate support is raised to a raised position using the actuator 116. The substrate support is raised using the actuator 116. The grounding assembly 160 described herein allows the substrate support to be coupled to the chamber body lower surface 148 in raised and lowered positions. Thus, a ground path is maintained throughout operation and for a variety of different processes performed at variable substrate support positions (e.g., different substrate support heights). The processes described herein include operating conditions with a larger gap between the upper and lower flanges. Grounding assemblies known in the art provide grounding for processes with a fixed gap, such as a narrow gap between the support body 112 and the chamber lower surface 148. The grounding assembly described herein provides a ground path throughout operation for a number of different processes with various gaps between the support body 112 and the chamber lower surface 148. Continuous grounding for various gaps between the support body 112 and the chamber lower surface 148 enables a wide process window. In some embodiments, which may be combined with other embodiments described herein, the gap between the support body 112 and the chamber lower surface 148 is about 6 mm to about 51 mm. Continuous grounding as described herein enables stable processing, such as during film deposition, alternatively or additionally during plasma cleaning of the chamber. Continuous grounding as described herein reduces the risk of any asymmetric parasitic plasma generated by loose ground contact. Ground strap designs known in the art rely on spring constants to ensure complete contact with the ground path, which is unreliable and requires frequent preventative maintenance. It is possible to secure the ground strap to one or more sides of the chamber. However, such an arrangement limits the gap size between the support body 112 and the lower chamber lower surface 148.

[0034]

[0044] In operation 606, gas is introduced into the upper volume 110. The gas is supplied from a gas source 130 coupled to the lid 104 and introduced from the gas source 130 into the upper volume 110 through the face plate 106.

[0035]

[0045] In operation 608, the gas is excited using electromagnetic energy, such as radio frequency energy, to generate a plasma via capacitive coupling. The excited gas is used to deposit material on a substrate. The radio frequency follows an RF path from the substrate support through the plasma in the upper space 110 to the bottom of the chamber body, through the grounding assembly 160 to the ground plate 146, and through the conductive rods 114 to ground. The RF return path provides a suitable path for RF transport, thereby substantially reducing the occurrence of RF leakage, the creation of parasitic plasma, and arcing within the spaces 110 and 111. As used herein, the term “parasitic plasma” refers to plasma within the space outside the upper space 110. In particular, plasma found within the lower space 111 of the spaces is considered “parasitic plasma.” In some embodiments, which may be combined with other embodiments disclosed herein, the lower space 111 includes a voltage within the gas in the lower space 111 of less than 100 V. A voltage of less than 100 V in the gas in the lower volume 111 demonstrates that RF leakage into the lower volume 111 is minimized by the grounding assembly 160 disclosed herein. The grounding assembly 160 provides an RF path from the substrate support 105 to ground and reduces the voltage of the gas in the lower volume 111 by preventing RF leakage into the lower volume 111. The grounding assembly 160 of the present disclosure is useful for processing substrates in plasma-enhanced chemical vapor deposition, etching processes, or any process that uses an RF source provided to the lower surface 156 of the support body 112.

[0036]

[0046] The particular features, structures, compositions, materials, or characteristics described herein may be combined in any suitable manner in one or more embodiments. Although the disclosure herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and system. Thus, it is intended that the present invention cover such modifications and variations provided they come within the scope of the appended claims and their equivalents.

Claims

1. a chamber body and a lid defining an interior space; a substrate support positioned in the space opposite the lid, a support body disposed on the stem and configured to be coupled to a radio frequency source provided through the stem; a ground plate disposed between the support body and the stem; an upper flange coupled to a lower peripheral surface of said ground plate; a lower flange coupled to a lower portion of the chamber body; and An apparatus comprising: a plurality of straps, each of the plurality of straps having a first end coupled to the lower flange and a second end coupled to the upper flange.

2. The device of claim 1 , wherein the plurality of straps comprises between 10 and 20 straps.

3. The device of claim 2 , wherein the plurality of straps comprises between 12 and 16 straps.

4. 10. The apparatus of claim 1, wherein each of the plurality of straps is constructed from a metal including stainless steel, inconel, carbon, chromium, nickel, manganese, silicon, nitrogen, phosphorus, sulfur, or a combination thereof.

5. 2. The apparatus of claim 1, wherein the first end of each of the plurality of straps is coupled to a recess in the upper surface of the lower flange using a screw, and the second end of each strap is coupled to a recess in the lower surface of the upper flange using a screw.

6. The device of claim 5 , wherein each of the screws comprises stainless steel.

7. The apparatus of claim 1 , wherein the upper flange comprises a metal including steel, aluminum, alloys thereof, or combinations thereof.

8. The apparatus of claim 1 , wherein the lower flange is coupled to the lower portion of the chamber using a plurality of stainless steel fasteners.

9. The apparatus of claim 1 , wherein each of the plurality of straps is configured to bend radially inward when the substrate support is in a retracted position.

10. 10. The device of claim 1, wherein each strap has a spring constant of from 17 lbs / in to about 20 lbs / in.

11. 2. The device of claim 1, wherein the minimum distance between the upper flange and the lower flange is greater than 6 mm.

12. The device of claim 1 further comprising a conductive rod extending through the stem.

13. The apparatus of claim 12 , wherein the conductive rod is configured to be coupled to ground.

14. 1. A method of processing a substrate, comprising: placing a substrate on a substrate support within a volume of a processing chamber, the substrate support being disposed opposite a lid within the volume, the substrate support comprising: a support body disposed on a stem and configured to be coupled to a radio frequency source supplied via the stem; a ground plate disposed between the support body and the stem; and an upper flange coupled to a lower peripheral surface of the ground plate; the processing chamber comprising: a lower flange coupled to a lower portion of the chamber volume; and a plurality of straps, each of the plurality of straps having a first end coupled to the lower flange and a second end coupled to the upper flange; raising the substrate support to a raised position to form an upper portion of the space; introducing a gas into the upper portion of the space; and exciting the gas with radio frequency energy.

15. The method of claim 14 , wherein the lower portion of the space is substantially free of plasma.

16. The method of claim 14, comprising treating the substrate with a plasma enhanced chemical vapor deposition or etching process.

17. 15. The method of claim 14, wherein lifting the substrate support to a raised position comprises lifting the ground plate and maintaining a high frequency path from the lower flange to the ground plate through at least one of the plurality of straps.

18. A system having an algorithm stored in a memory, said algorithm comprising a number of instructions which, when executed by a processor, cause the system to perform the method of claim 14.

19. an upper flange including an upper flange upper surface and an upper flange lower surface; a lower flange including a lower flange upper surface and a lower flange lower surface, the lower flange comprising a lower portion extending radially inward from an inner diameter of the lower flange, the lower portion including one or more apertures configured to receive screws; a plurality of straps, each of the plurality of straps having a first end coupled to the lower flange and a second end coupled to the upper flange; the upper flange lower surface includes a recess configured to receive the second end of each of the plurality of straps, and the lower flange upper surface includes a recess configured to receive the first end of each of the plurality of straps.

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