Extending ground strip service life in PECVD process chamber
By adopting multiple grounding strips and ceramic plate designs in the PECVD process chamber, the problem of short service life of the grounding strip is solved, and the service life is extended and the chamber performance is improved.
Patent Information
- Application Number
- CN202411603481.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2017-06-01
- Publication Date
- 2025-03-21
AI Technical Summary
In PECVD process chambers, the grounding belt has a short service life and is prone to breakage, resulting in high chamber shutdown and maintenance costs.
A plurality of ground strips are coupled to the substrate support and the bottom of the chamber, the first end of the ground strip is vertically offset from the second end, and an L-shaped stop is installed at one or both ends to reduce the exposure length. In addition, the ceramic plate is coupled to the outer periphery of the substrate support to reduce film deposition.
It extends the service life of the ground zone, improves the overall performance of the chamber, reduces RF frequency changes, reduces maintenance costs, and improves the uniformity of film deposition.
Smart Images
Figure CN119663247A_ABST
Abstract
Description
[0001] This application is a divisional application of an invention patent application with an application date of June 1, 2017, application number 201780091524.8, and name “Extending the service life of a grounding strap in a PECVD process chamber”. Technical Field
[0002] Examples of the present disclosure generally relate to apparatus and methods for extending the useful life of ground straps in substrate processing chambers, such as plasma enhanced chemical vapor deposition (PECVD) chambers. Background Art
[0003] PECVD is used to process substrates such as solar substrates, display substrates, and semiconductor substrates. PECVD generally involves introducing precursor gases into a vacuum chamber where the substrate is placed on a substrate support. The precursor gases are introduced into the vacuum chamber through a gas distribution plate typically positioned near the top of the chamber and excited by radio frequency (RF) power applied to the gas distribution plate to generate a plasma between the gas distribution plate and the substrate on the substrate support. The excited gases react to form a thin film layer on the substrate positioned on the substrate support.
[0004] During processing, the substrate support requires RF grounding to eliminate any voltage drop across the substrate support, which would otherwise affect deposition uniformity. If the substrate support is not properly RF grounded and high impedance is present, parasitic plasma will generally deposit on the substrate support and chamber walls. The substrate support is typically grounded to the chamber body by a ground strap to form an RF current return path.
[0005] The useful life of the ground strap is measured by the number of substrates processed. Conventional ground straps are typically thin, flexible aluminum straps that are susceptible to breaking, especially over time and when the substrate support is moved between the home position and the processing position, or when exposed to plasma leaks. Each time a ground strap breaks, it results in chamber downtime for maintenance and the cost of replacing the ground strap.
[0006] Therefore, what is needed is an improved substrate processing chamber having a ground strap with an extended useful life. Summary of the invention
[0007] The present disclosure relates to methods and apparatus for extending the useful life of ground straps. In one example, a substrate processing chamber includes a plurality of ground straps coupled to a substrate support and a chamber bottom. A first end of the ground strap is vertically offset from a second end of the ground strap. In another example, a substrate processing chamber includes one or more ceramic plates coupled to an outer periphery of the substrate support to reduce film deposition on the chamber wall, substrate support, and ground strap. In yet another example, a substrate processing chamber includes one or more ground straps coupled to a substrate support and a chamber bottom. Each ground strap includes an L-shaped stopper at one or both ends thereof to reduce the exposed length of the ground strap. The apparatus and the method extend the useful life of the ground strap, improve overall chamber performance, and reduce RF frequency variations within the chamber.
[0008] In one example, a substrate processing chamber is disclosed. The chamber includes: a chamber body having: one or more chamber walls; and a chamber bottom having a first bottom connector and a second bottom connector; a substrate support disposed in the chamber body, the substrate support having at least a first support connector, a second support connector, and a third support connector; a first ground strap having a first end and a second end, the first end being coupled to the substrate support at the first support connector and the second end being coupled to the chamber bottom at the second bottom connector; and a second ground strap having a first end and a second end, the first end being coupled to the substrate support at the second support connector and the second end being coupled to the chamber bottom at the third bottom connector.
[0009] In another example, a substrate processing chamber is disclosed. The substrate processing chamber includes: a chamber body, the chamber body having: one or more chamber walls; and a chamber bottom; a substrate support, the substrate support disposed in the chamber body, the substrate support having an outer periphery facing the one or more chamber walls; one or more ground straps, the one or more ground straps having a first end and a second end, the first end coupled to the substrate support, the second end coupled to the chamber bottom; and one or more ceramic plates, the one or more ceramic plates coupled to the outer periphery of the substrate support.
[0010] In yet another example, a substrate processing chamber is disclosed. The substrate processing chamber includes: a chamber body having: one or more chamber walls; and a chamber bottom; a substrate support disposed in the chamber body; one or more ground straps having a first end and a second end, the first end coupled to the substrate support and the second end coupled to the chamber bottom; a first L-shaped stop and clamp at the first end; and a second L-shaped stop and clamp at the second end, each of the first L-shaped stop and the second L-shaped stop having a first portion and a second portion that intersect at an angle greater than about 90 degrees. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In order to be able to understand in detail the manner of the above-mentioned features of the present disclosure, a more specific description of the present disclosure briefly summarized above can be obtained with reference to examples, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show exemplary examples and therefore should not be regarded as limiting the scope of the present disclosure, but other equivalent examples may be allowed.
[0012] Figure 1 is a cross-sectional view of a substrate processing system having one or more ground straps therein.
[0013] Figure 2 is a top view of an exemplary ground strap.
[0014] Figure 3 yes Figure 1 A cross-sectional view of a portion of a substrate processing chamber.
[0015] Figure 4A yes Figure 1 A cross-sectional view of a portion of a substrate processing chamber.
[0016] Figure 4B yes Figure 1 A cross-sectional view of a portion of a substrate processing chamber.
[0017] Figure 4C yes Figure 1 A cross-sectional view of a portion of a substrate processing chamber.
[0018] Figure 5A is a cross-sectional view of a substrate processing system having one or more ceramic plates therein.
[0019] Figure 5B yes Figure 5A Schematic diagram of one or more ceramic plates.
[0020] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and / or features of one example may be beneficially incorporated in other examples without further recitation. DETAILED DESCRIPTION
[0021] The present disclosure relates to methods and apparatus for extending the useful life of ground straps. In one example, a substrate processing chamber includes a plurality of ground straps coupled to a substrate support and a chamber bottom. A first end of the ground strap is vertically offset from a second end of the ground strap. In another example, a substrate processing chamber includes one or more ceramic plates coupled to an outer periphery of the substrate support to reduce film deposition on the chamber wall, substrate support, and ground strap. In yet another example, a substrate processing chamber includes one or more ground straps coupled to a substrate support and a chamber bottom. Each ground strap includes an L-shaped stopper at one or both ends thereof to reduce the exposed length of the ground strap. The apparatus and the method extend the useful life of the ground strap, improve overall chamber performance, and reduce RF frequency variations within the chamber.
[0022] Figure 1 1 is a cross-sectional view of a substrate processing system 100, such as a PECVD chamber. The substrate processing system 100 includes a substrate processing chamber 102, which is coupled to a gas source 104. The substrate processing chamber 102 includes chamber walls 106 and a chamber bottom 108 (collectively referred to as a chamber body 101), which partially define a processing volume 110. Access to the processing volume 110 is generally through a slit valve 112 in the chamber wall 106, which facilitates the movement of a substrate 114 into and out of the substrate processing chamber 102. The chamber wall 106 and the chamber bottom 108 are generally made of a unitary piece of aluminum or other suitable material for substrate processing. The chamber wall 106 supports a lid assembly 116.
[0023] The gas distribution plate 126 is suspended in the substrate processing chamber 102 from a backing plate 128 coupled to the lid assembly 116. In other examples, the gas distribution plate 126 and the backing plate 128 are made of a single piece of material. The gas distribution plate 126 is generally perforated so that the precursor gas is evenly distributed into the substrate processing chamber 102.
[0024] The substrate support 118 is generally disposed centrally within the substrate processing chamber 102. The substrate support 118 supports the substrate 114 during processing. Typically, the substrate support 118 is made of a conductive material, such as aluminum, that encapsulates at least one temperature control device that controllably heats or cools the substrate support 118 to maintain the substrate 114 at a predetermined temperature during processing.
[0025] The substrate support 118 has a first surface 120 and a second surface 122. The first surface 120 is opposite the second surface 122, and a third surface 121 coupling the first surface 120 to the second surface 122 is perpendicular to the first surface 120 and the second surface 122. The first surface 120 supports the substrate 114. The second surface 122 has a rod 124 coupled thereto. The rod 124 couples the substrate support 118 to a lift system (not shown) that moves the substrate support 118 between a raised processing position (as shown) and a lowered position that facilitates transfer of substrates into and out of the processing chamber 102. The rod 124 also provides a conduit for electrical and thermal coupling leads between the substrate support 118 and other components of the substrate processing chamber 100.
[0026] Any suitable number of ground straps 130 ground the substrate support 118 to the chamber bottom 108 to form a low impedance RF current return path between the substrate support 118 and the chamber bottom 108 of the chamber body 101 .
[0027] In operation, when a precursor gas is introduced into the substrate processing chamber 102 and ignited into a plasma, the generated plasma forms a thin film on the substrate 114. In addition to depositing a thin film on the substrate, the generated plasma generally leaks into other parts of the chamber, thereby becoming a parasitic plasma that forms undesirable films on various chamber components such as the chamber walls 106, the chamber bottom 108, the substrate support 118, and the ground strap 130.
[0028] Figure 2 is a top view of an exemplary ground strap 130. The body 232 of the ground strap 130 is generally a thin, flexible rectangular sheet of aluminum material having a first end 234 and a second end 236 with a slit 238 centered along the body 232 between the first end 234 and the second end 236. In one example, the ground strap 130 is also fabricated with one or more folds 240 centered along the slit 238 between the first end 234 and the second end 236. In another example, the one or more folds 240 occur when the substrate support 118 is raised from a lower, home position to a higher, processing position during processing, thereby bending the ground strap 130 and forming the one or more folds 240. Figure 2 Only one example of a ground strap 130 is shown. The ground strap 130 is generally of any size, shape, and material suitable for substrate processing.
[0029] Figure 3 Based on an example Figure 1 1 is a cross-sectional view of a portion 300 of a substrate processing chamber 102. Figure 3As shown, the substrate support 118 includes one or more support connectors 350 coupled thereto. Figure 3 108. The chamber bottom 108 includes one or more bottom connectors 352. The first bottom connector 352a, the second bottom connector 352b, the third bottom connector 352c, the fourth bottom connector 352d and the fifth bottom connector 352e are shown respectively. In one example, the first support member connector 350a and the first bottom connector 352a are aligned in a substantially vertical plane (y). In another example, the first bottom connector 352a is vertically offset from the first top connector 350a.
[0030] Each of the ground straps 130 (three indicated as 130 a , 130 b , and 130 c ) is coupled to the substrate support 118 at a first end 234 and to the chamber bottom 108 at a second end 236 .
[0031] According to an example of the present disclosure, Figure 3 As shown, the first end 234a of the first grounding strap 130a is coupled to the first support member connector 350a; however, the second end 236a is coupled to the second bottom connector 352b such that the second end 236a is vertically offset from the first end 234a. The first end 234b of the second grounding strap 130b is coupled to the second support member connector 350b, while the second end 236b is coupled to the third bottom connector 352c such that the second end 236b is vertically offset from the first end 234b. The first end 234c of the third grounding strap 130c is coupled to the third support member connector 350c, while the second end 236c is coupled to the fourth bottom connector 352d such that the second end 236c is vertically offset from the first end 234c. Although Figure 3 , three ground straps 130 are shown, but the vertically offset positions of the first end 234 and the second end 236 are applicable to any number of ground straps 130. The distance along the horizontal axis (x) between each of the bottom connectors 352 is generally any suitable distance, for example, between about 5 inches and about 10 inches, such as between about 6 inches and about 9 inches.
[0032] According to another example of the present disclosure, the first end 234a of the first ground strap 130a is coupled to the first support member connector 350a; however, the second end 236a is coupled to the third bottom connector 352c, such that the second end 236a is more vertically offset from the first end 234a. The first end 234b of the second ground strap 130b is coupled to the second support member connector 350b, and the second end 236b is coupled to the fourth bottom connector 352d, such that the second end 236b is more vertically offset from the first end 234b. The first end 234c of the third ground strap 130c is coupled to the third support member connector 350c, and the second end 236c is coupled to the fifth bottom connector 352e, such that the second end 236c is more vertically offset from the first end 234c.
[0033] Although the above examples contemplate first end 234 being offset from second end 236 by one or two bottom connector positions, it is also contemplated that second end 236 is vertically offset along the x-axis by any suitable distance, such as three or more bottom connector positions, or less than one bottom connector position.
[0034] Conventionally, the first end 234a of the first ground strap 130a is coupled to the first support connector 350a, and the second end 236a is coupled to the first bottom connector 352a. In conventional positioning, the one or more folds 240 are centered between the substrate support 118 and the chamber bottom 108. Therefore, during processing, the central portion of the ground strap 130 having the one or more folds 240 is exposed to the parasitic plasma 354, which reduces the useful life of the ground strap 130.
[0035] Generally, in accordance with the present disclosure, the second end 236 of one or more grounding straps 130 is mounted in a counterclockwise direction (when viewed from above) at one or more bottom connector 352 locations from a position directly below or substantially vertically below a corresponding support connector. In the vertically offset positioning of the present disclosure, one or more folds 240 are located near the chamber bottom 108, for example, greater than 50% away from the substrate support in the y-direction. In another example, one or more folds are within 40% in the y-direction adjacent to the chamber bottom 108. In another example, one or more folds 240 are positioned greater than fifty percent away from the first end 234. In operation, the position of the first end 234 vertically offset from the second end 236 of the corresponding grounding strap 130 reduces exposure of one or more folds 240 to parasitic plasma 354 generated during processing. As Figure 3 As shown, the parasitic plasma 354 is located proximate the substrate support 118. Reduced exposure to the parasitic plasma 354 extends the useful life of the ground strap 130. As an additional benefit, the offset positioning of the present disclosure improves film deposition uniformity.
[0036] Figure 4A yes Figure 1 A cross-sectional view of a portion 400 of a substrate processing chamber 102 is shown. Figure 4A As shown, the substrate processing chamber 102 further includes a first L-shaped stop and clamp assembly 460 and a second L-shaped stop and clamp assembly 470. One or more ground straps 130 (one is shown) are coupled to the substrate support 118 through the first L-shaped stop and clamp assembly 460, and coupled to the chamber bottom 108 through the second L-shaped stop and clamp assembly 470. Figure 4B is an enlarged cross-sectional view of the first L-shaped block and clamp assembly 460 . Figure 4C is an enlarged cross-sectional view of the second L-shaped block and clamp assembly 470.
[0037] like Figure 4B As shown, the first L-shaped stop and clamp assembly 460 generally includes a first L-shaped stop 462 and a first clamp 464. The first L-shaped stop 462 is coupled to the substrate support 118 via a first coupling mechanism 466. In one example, the first coupling mechanism 466 is a screw; however, the first coupling mechanism 466 is generally any suitable coupling mechanism. The first clamp 464 is coupled to the first L-shaped stop 462 via a second coupling mechanism 468. In one example, the second coupling mechanism 468 is a screw; however, the second coupling mechanism 468 is generally any suitable coupling mechanism. The first L-shaped stop 462 further includes a first portion 462a and a second portion 462b. The first portion 462a and the second portion 462b intersect at an angle (∠A) greater than about 90°. In one example, ∠A is between about 100° and about 120°, for example, about 116.5°. The first clamp 464 intersects the substrate support 118 at an angle (∠B) that is less than about 90°. In one example, ∠B is between about 60° and about 80°, for example, about 63.5°. A space 469 is formed between the first L-shaped stop 462 and the first clamp 464. The space 469 is generally configured to hold the first end 234 of the ground strap 130 so that the first end 234 of the ground strap 130 slides between the first L-shaped stop 462 and the first clamp 464. In one example, the first end 234 of the ground strap 130 is coupled to the first L-shaped stop 462 and the first clamp 464, for example, by a second coupling member 468. In another example, the space 469 between the first L-shaped stop 462 and the first clamp 464 is sized to tightly hold the first end 234 of the ground strap 130 therebetween.
[0038] like Figure 4CAs shown, the second L-shaped block and clamp assembly 470 is substantially similar to the first L-shaped block and clamp assembly 470. The second L-shaped block and clamp assembly 470 generally includes a second L-shaped block 472 and a second clamp 474. The second L-shaped block 472 is coupled to the chamber bottom 108 via a first coupling mechanism 476. In one example, the first coupling mechanism 476 is a screw; however, the first coupling mechanism 476 is generally any suitable coupling mechanism. The second clamp 474 is coupled to the second L-shaped block 472 via a second coupling mechanism 478. In one example, the second coupling mechanism 478 is a screw; however, the second coupling mechanism 478 is generally any suitable coupling mechanism. The second L-shaped block 472 further includes a first portion 472a and a second portion 472b. The first portion 472a and the second portion 472b intersect at an angle (∠A) greater than about 90°. In one example, ∠A is between about 100° and about 120°, for example, about 116.5°. The second clamp 474 intersects the chamber bottom 108 at an angle (∠B) less than about 90°. In one example, ∠B is between about 60° and about 80°, for example, about 63.5°. A space 479 is formed between the second L-shaped stop 472 and the second clamp 474. The space 479 is generally configured to hold the second end 236 of the ground strap 130 so that the second end 236 of the ground strap 130 slides between the second L-shaped stop 472 and the second clamp 474. In one example, the second end 236 of the ground strap 130 is coupled to the second L-shaped stop 472 and the second clamp 474, for example, by a second coupling member 478. In another example, the space 479 between the second L-shaped stop 472 and the second clamp 474 is sized to tightly hold the second end 236 of the ground strap 130 therebetween.
[0039] In one example, the first L-shaped stop and clamp assembly 460 and the second L-shaped stop and clamp assembly 470 reduce the exposed portion 480 of the ground strap 130. In another example, the ground strap 130 is manufactured to a shorter length because the first L-shaped stop and clamp assembly 460 and the second L-shaped stop and clamp assembly 470 reduce the length of the ground strap 130 required to ground the substrate support 118 to the chamber bottom 108. In one example, the first L-shaped stop and clamp assembly 460 and the second L-shaped stop and clamp assembly 470 reduce the total length or exposed length of the ground strap 130 by about 25%. For example, the length across one or more ground straps 130 is between about 30 centimeters (cm) and about 50 cm, such as between about 40 cm and about 45 cm. The reduced length, or total length, of the exposed portion 480 of the ground strap 130 extends the useful life of the ground strap 130 by improving RF grounding efficiency and reducing impedance between the substrate support 118 and the chamber bottom 108. Additionally, due to the reduced potential buildup on the substrate support 118, the intensity of the parasitic plasma is reduced.
[0040] Figure 5A is a cross-sectional view of a substrate processing system 500. The substrate processing system 500 is similar to the substrate processing system 100. Similar to the substrate processing system 100, the substrate processing system 500 includes a substrate support 118 having a first surface 120 for supporting a substrate 114, a second surface 122 opposite to the first surface 120, and a third surface 121 perpendicular to the first surface 120 and the second surface 122; however, the substrate processing system 500 further includes one or more ceramic plates 590, which are coupled to the substrate support 118. Additionally, the substrate support 118 may include one or more L-shaped stops 594, which are coupled to the substrate support 118 near the third surface 121. The one or more L-shaped stops 594 generally include a first portion and a second portion perpendicular to the first portion. In one example, the first portion of the one or more L-shaped stops 594 is coupled to the second surface 122 of the substrate support 118. Figure 5B is a schematic diagram of one or more ceramic plates 590 coupled to the substrate support 118. In one example, the one or more ceramic plates 590 are coupled to the third surface 121 corresponding to the outer perimeter of the substrate support 118. In another example, the one or more ceramic plates 590 are coupled to one or more L-shaped stops 594, which are coupled to the substrate support 118. Figure 5B As shown, one or more ceramic plates 590 are coupled to the substrate support 118 via one or more fastening mechanisms 596 (two are shown for each of the one or more ceramic plates 590). Figure 5B In the example shown in , the one or more fastening mechanisms 596 are screws; however, any suitable fastening mechanism may be used, such as rivets or bolts.
[0041] In one example, one or more ceramic plates 590 are rectangular with a length (I) and a width (w). The width of one or more ceramic plates 590 generally extends below the second surface 122 of the substrate support 118. For example, the length of each of the one or more ceramic plates 590 is between about 4 inches and about 6 inches, such as about 5 inches, and the width of each of the one or more ceramic plates 590 is between about 3 inches and about 5 inches, such as about 4 inches. In another example, one or more ceramic plates 590 are square. In another example, the width and length of one or more ceramic plates 590 are generally any length and width suitable for the substrate processing chamber. For example, the width of one or more ceramic plates 590 can be greater than 6 inches to cover a larger portion of one or more grounding straps 130.
[0042] In operation, the one or more ceramic plates 590 separate parasitic plasma between the substrate support 118 and various components of the substrate processing chamber 102, including the chamber walls 106 and the chamber bottom 108, and reduce parasitic plasma leakage in the substrate processing system 500. By reducing parasitic plasma leakage, the amount of parasitic plasma induced film deposition on components of the substrate processing system 500, including the chamber body 101, the substrate support 118, and the grounding strap 130, is reduced or eliminated. Additionally, the one or more ceramic plates 590 shield at least a portion of the one or more grounding straps 130 during processing. The one or more ceramic plates 590 extend the useful life of the one or more grounding straps 130.
[0043] Although the above description discusses various apparatuses and methods for extending the useful life of one or more ground straps in sequence, the disclosed apparatuses and methods may also be used individually or in any combination.
[0044] Benefits of the present disclosure include extending the useful life of ground straps by up to or more than 200%, e.g., to greater than 12,000 processed substrates, and thereby reducing chamber component wear and maintenance costs. Additionally, the disclosed apparatus and methods provide better substrate processing chamber performance, e.g., by less byproduct film formation on the chamber body and reduced RF frequency variation in the substrate processing chamber.
[0045] While the foregoing is directed to examples of the present disclosure, other and further examples of the disclosure may be devised without departing from the basic scope thereof, and the scope of the disclosure is determined by the appended claims.
Claims
1. A substrate processing chamber, comprising: A chamber body, the chamber body comprising: one or more chamber walls; and a chamber bottom having a first bottom connector, a second bottom connector, and a third bottom connector; a substrate support disposed in the chamber body, the substrate support having at least a first support connector, a second support connector, and a third support connector; a first ground strap having a first end and a second end, the first end being coupled to the substrate support at the first support connector and the second end being coupled to the chamber bottom at the second bottom connector, wherein the second end of the first ground strap is vertically offset from the first end of the first ground strap; and a second ground strap having a first end and a second end, the first end being coupled to the substrate support at the second support connector and the second end being coupled to the chamber bottom at the third bottom connector, wherein the second end of the second ground strap is vertically offset from the first end of the second ground strap, wherein the position in which the first end of the first ground strap is vertically offset from the second end of the first ground strap reduces exposure of one or more folds to parasitic plasma generated during processing, and The position in which the first end of the second ground strap is vertically offset from the second end of the second ground strap reduces exposure of one or more folds to parasitic plasma generated during processing.
2. The chamber of claim 1, wherein a distance along a horizontal axis between the first bottom connector and the second bottom connector is between about 6 inches and about 9 inches.
3. The chamber of claim 1, wherein the one or more folds are positioned within forty percent adjacent the second end.
4. The chamber of claim 1, wherein the one or more folds are positioned more than fifty percent away from the first end.
5. A substrate processing chamber, comprising: A chamber body, the chamber body comprising: one or more chamber walls; and Chamber bottom; a substrate support disposed in the chamber body, the substrate support having a first surface, a second surface, and a third surface, the third surface being perpendicular to the first surface and the second surface and facing the one or more chamber walls; one or more ground straps having a first end coupled to the substrate support and a second end coupled to the chamber bottom, wherein the second end is vertically offset from the first end of a respective ground strap; and One or more ceramic plates are coupled to the substrate support, each ceramic plate having a length and a width, the width being parallel to the third surface and extending below the second surface.
6. The chamber of claim 5, further comprising an L-shaped stop coupled to the substrate support, and wherein the one or more ceramic plates are coupled to the L-shaped stop.
7. The chamber of claim 5, wherein each of the one or more ceramic plates is rectangular.
8. The chamber of claim 7, wherein the length of each of the one or more ceramic plates is between about 4 inches and about 6 inches, and wherein the width of each of the one or more ceramic plates is between about 3 inches and about 5 inches.
9. The chamber of claim 5, wherein each of the one or more ceramic plates is square in shape.
10. The chamber of claim 5, wherein the one or more ceramic plates separate the one or more chamber walls from at least a portion of the one or more ground straps.
11. A substrate processing chamber, comprising: A chamber body, the chamber body comprising: one or more chamber walls; and Chamber bottom; a substrate support disposed in the chamber body; one or more ground straps, the one or more ground straps having a first end coupled to the substrate support and a second end coupled to the chamber bottom, wherein the second end is vertically offset from the first end of a respective ground strap; a first L-shaped stop and clamp at the first end; and a second L-shaped stop and clamp at the second end, each of the first L-shaped stop and the second L-shaped stop having a first portion and a second portion that intersect at an angle greater than about 90 degrees, Wherein the second L-shaped block and clamp are vertically offset from the first L-shaped block and clamp.
12. The chamber of claim 11, wherein the angle is between about 100 degrees and about 140 degrees.
13. The chamber of claim 11, wherein an exposed length of each of the one or more ground straps is between about 40 centimeters and about 45 centimeters.
14. The chamber of claim 11, wherein the first L-shaped stop is coupled to the substrate support.
15. The chamber of claim 11, wherein the second L-shaped stop is coupled to the chamber bottom.