Improvement of film thickness uniformity using edge ring and shape dimension of bias electrode

Abstract

To provide an edge ring for providing a high uniformity.SOLUTION: An edge ring 140b for a substrate treatment includes a bottom surface 240, an upper surface, an inner surface that connects the bottom surface 240 and the upper surface and forms an opening with a center axis as a center, multiple projection parts 206 that extend from the upper surface and are arranged at an interval around the opening, and a circular groove 306 extending from the multiple projection parts 206 to an outside in a diameter direction.SELECTED DRAWING: Figure 2B

Description

[Technical field]

[0001]

[0001] Embodiments of the present disclosure relate generally to integrated circuit manufacturing and to an apparatus for use in a substrate processing chamber to improve film thickness uniformity. [Background technology]

[0002]

[0002] A primary goal in substrate processing is to obtain the greatest possible useful surface area, and therefore the greatest number of chips, from each substrate. Several factors to be considered include process variables that affect the uniformity and thickness of layers deposited on the substrate, as well as contaminants that may adhere to the substrate and render all or part of the substrate useless. By controlling these factors, the useful surface area of ​​each substrate being processed can be maximized.

[0003]

[0003] Recent developments in semiconductor processing have generated interest in new processing applications requiring low ion current and high ion energy, which allows deep processing without film growth. To meet the low ion current, high ion energy requirements, bias powers that exceed the source power by a factor of 10 to 20 or more have been used. At such high bias power to source power ratios, the plasma density and the plasma current to the substrate are affected. The effect on the plasma current and plasma density results in thicker film thickness toward the substrate edge.

[0004]

[0004] Edge rings have traditionally been used to improve film thickness uniformity by altering the deposition rate near the edge of the substrate. However, typical edge rings still result in poor uniformity and deposition rate near the extreme edge of the substrate. Thus, there is a need in the art for an edge ring that provides greater uniformity. Summary of the Invention

[0005]

[0005] Embodiments of the present disclosure generally relate to an apparatus for improving film thickness near the edge of a substrate during low ion current and high ion energy applications.

[0006] In one embodiment, a substrate processing apparatus includes an edge ring and an overhang ring. The edge ring includes a bottom surface, a top surface, and a groove disposed in the top surface. The overhang ring includes a first portion disposed in the groove and extending from the groove, and a second portion connected to the first portion and extending radially inward.

[0007] In another embodiment, a substrate processing apparatus includes an edge ring and an overhang ring. The edge ring includes a bottom surface, a top surface, a central opening, and a groove disposed in the top surface. The overhang ring includes a first portion disposed in the groove and extending upwardly from the groove, and a second portion extending radially inward toward a central axis of the overhang ring.

[0008] In yet another embodiment, a substrate processing apparatus includes an edge ring and an overhang ring. The edge ring further includes a support surface, a top surface, a groove disposed in the top surface, and a plurality of tabs disposed in the top surface. The overhang ring further includes a first portion disposed in the groove and extending from the groove, and a second portion connected to the first portion and extending radially inward.

[0009]

[0009] In order that the above-mentioned features of the present disclosure may be understood in detail, the present disclosure summarized above will now be more particularly described with reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings merely depict exemplary embodiments, and therefore should not be considered as limiting the scope of the present disclosure, which may admit of other equally effective embodiments. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a process chamber. [Figure 2A]2 is a cross-sectional view of an edge ring for use in the process chamber of FIG. 1. [Figure 2B] 2 is a cross-sectional view of an edge ring for use in the process chamber of FIG. 1. [Figure 3A] FIG. 2C is a schematic plan view of the edge ring of FIG. 2B. [Figure 3B] FIG. 2C is a schematic cross-sectional view of the edge ring of FIG. 2B. [Figure 4] FIG. 4 is a cross-sectional view of an overhang ring utilized with the edge ring of FIGS. 3A-3B. [Figure 5A] FIG. 3C is a partial cross-sectional view of the edge ring of FIGS. 3A-3B. [Figure 5B] FIG. 3C is a partial cross-sectional view of the edge ring of FIGS. 3A-3B. [Figure 6] 1 is a graph showing film thickness on a substrate using two different edge rings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011]

[0017] To facilitate understanding, wherever possible, the same reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0012]

[0018] FIG. 1 is a schematic cross-sectional view of a process chamber 100. The process chamber 100 is an inductively coupled plasma (ICP) chamber. The process chamber 100 includes an inductive coil 114, a lid 104, a first radio frequency (RF) power supply 116, a chamber body 102, a pedestal assembly 106, a substrate 126, an edge ring assembly 138, and a second RF power supply 128. The first process chamber is capable of generating a plasma therein. The plasma includes a first plasma region 120 surrounded by a second plasma region 122 of lower plasma density. The first plasma region 120 and / or the second plasma region 122 are electrically coupled to ground via a plurality of RF current lines 124.

[0013]

[0019] The induction coil 114 is disposed on the lid 104 of the process chamber 100. The induction coil 114 is centered around the central axis 1 of the process chamber 100. The induction coil 114 transmits source power for the process chamber 100. The source power is RF power received from an RF power source 116. The induction coil receives RF power of about 50W to about 500W for transmission into the interior of the process chamber 100. In some embodiments, the induction coil may receive RF power of about 50W to about 250W, such as about 50W to about 200W, such as about 50W to about 150W, such as about 75W to about 150W, such as about 100W. The first RF power source and the induction coil 114 are connected by a first connection 132 at one end of the induction coil 114. The first connection 132 may be one or more wires or cables.

[0014]

[0020] The induction coil 114 may further be attached to a second connection 134. The second connection 134 is similar to the first connection 132. The second connection is connected to ground 118. Connecting the second connection to ground 118 connects the induction coil 114 to ground.

[0015]

[0021] The electrostatic chuck 110 is powered by a second RF power source 128. The second RF power source 128 generates a bias power for the process chamber 100. The second RF power source 128 may generate an RF power of about 500 W to about 3000 W applied to the electrostatic chuck 110. In some embodiments, the second RF power source 128 may generate an RF power of about 600 W to about 2500 W applied to the electrostatic chuck 110, such as about 700 W to about 2250 W, such as about 750 W to about 2200 W, such as about 800 W to about 2000 W. The second RF power source 128 and the electrostatic chuck are connected by a third connection 130. The third connection 130 may be one or more wires or cables.

[0016]

[0022] The lid 104 is a dielectric lid. The lid 104 is disposed over and covers the top of the process chamber 100. The lid 104 separates the inductive coil 114 from the processing region 150. The lid may be removable or may be hinged (not shown). The processing region 150 is within the chamber body 102 and is defined as the region within the chamber body 102 and the lid 104. The processing region 150 includes a pedestal assembly 106 for supporting the substrate 126 and an edge ring assembly 138. The first plasma region 120 and the second plasma region 122 are contained within the processing region 150 when generated.

[0017]

[0023] The pedestal assembly 106 includes a support 108, an electrostatic chuck 110, a second RF power supply 128, and an edge ring assembly 138. The electrostatic chuck 110 is disposed on the support 108. The electrostatic chuck 110 is sized to be disposed on the support 108 and to receive a substrate 126 on an upper surface of the electrostatic chuck 110. The edge ring assembly 138 is disposed on the support 108 and a portion of the electrostatic chuck 110. The edge ring assembly 138 is disposed around the periphery of the substrate 126.

[0018]

[0024] An edge ring assembly 138 surrounds the substrate 126. The edge ring assembly 138 includes an overhang ring 112 and an edge ring 140. The overhang ring 112 and the edge ring 140 are described in more detail herein.

[0019]

[0025] The first plasma region 120 is a region of high density plasma within the processing region 150. The second plasma region 122 is a region of low density plasma within the processing region 150. The second plasma region 122 surrounds the first plasma region 120 and has a lower plasma density than the first plasma region 120. The first and second plasma regions 120, 122 may be oxygen-based plasmas. Oxygen-based plasmas may be used when performing processes involving silicon oxides, such as silicon dioxide.

[0020]

[0026] A number of RF current lines 124 represent a connection between the surface of the substrate 126 and the sidewall of the chamber body 102. The RF current lines 124 in previous edge ring embodiments do not pass through either the first or second plasma regions 120, 122 during low pressure ICP substrate processing. However, an edge ring such as the edge ring assembly 138 and other edge ring assemblies described herein redirects the RF current lines 124 near the edge of the substrate so that the RF current lines pass through the first and second plasma regions 120, 122. The RF current lines 124 are redirected by the edge ring assembly 138 so that the current passes through the path of least resistance. Without being bound by theory, it is believed that the edge ring assembly 138 interrupts the low resistance path from the substrate to the sidewall of the chamber body 102. The RF current lines 124 are then pushed up through the first and second plasma regions 120, 122. This effect may be more pronounced when relatively high bias power is utilized. The RF current lines 124 passing through the first or second plasma regions 120, 122 reduce thickening near the edge of the substrate 126.

[0021]

[0027] 2A-2B are cross-sectional views of edge ring assemblies 138a and 138b used in the process chamber 100 of FIG. 1. The edge ring assemblies 138a, 138b are disposed on and around the outer edge of the electrostatic chuck 110 as shown in FIG. 1. The edge ring assemblies 138a, 138b include two different embodiments of edge rings 140a, 140b. The first embodiment of the edge ring assembly 138a shown in FIG. 2A includes a first edge ring 140a having a body 250a. The first edge ring 140a includes a body 250a, a cantilever 208 disposed radially inward of the body 250a, an outer body 202 disposed radially outward of the body 250a, and a plurality of vertical protrusions 206 disposed on the body 250a.

[0022]

[0028] The first edge ring 140a of FIG. 2A is one continuous (e.g., monolithic) body. The first edge ring 140a includes a vertically extending body 250a. The extending body 250a extends from an outer body 202. The outer body 202 is cylindrical and is the portion of the first edge ring 140a that is disposed adjacent the electrostatic chuck 110. The outer body 202 has a bottom surface 240. The bottom surface 240 is adjacent a top surface of the electrostatic chuck 110. The bottom surface 240 includes a step 242 radially inward of the outer body 202. The step 242 corresponds to and engages with a similar step portion of the electrostatic chuck 110.

[0023]

[0029] The outer body 202 further includes a radially inner cantilever 208. The cantilever 208 is the innermost portion of the edge ring 140a. The cantilever 208 is disposed adjacent to a substrate support surface 230 of the electrostatic chuck 110. The cantilever 208 has an upper cantilever surface 232 that is parallel to the substrate support surface 230. The upper cantilever surface 232 may be substantially coplanar with the substrate support surface 230. In some embodiments, the upper cantilever surface 232 is utilized to protect the underside of an edge of a substrate, such as the substrate 126. The edge of the substrate 126 may extend over at least a portion of the cantilever 208 during processing.

[0024]

[0030] The body 250a has a height H1. The height H1 of the extending body 250a can be from about 10 mm to about 40 mm, such as from about 15 mm to about 35 mm, such as from about 20 mm to about 30 mm. In some embodiments, the height H1 of the extending body 250a is about 25 mm. The extending body 250a has an inner surface 222 and an outer surface 218. In some embodiments, the height H1 is the height of the inner surface 222 of the extending body 250a. The inner surface 222 extends from the upper cantilever surface 232 to the bottom of the vertical protrusion 206.

[0025]

[0031] The inner surface 222 is the surface of the extending body 250a closest to the central axis of the edge ring assembly 138a. The outer surface 218 is the surface of the extending body 250a furthest from the central axis of the edge ring assembly 138a. The extending body 250a further includes a top surface 220. The top surface 220 connects the inner surface 222 and the outer surface 218. A vertical protrusion 206 is disposed on the top surface 220. The vertical protrusion 206 has a protrusion inner surface 216. The protrusion inner surface 216 is flush with the inner surface 222 of the extending body 250a. There may be multiple vertical protrusions 206 disposed on the extending body 250a. The multiple vertical protrusions 206 are evenly disposed around the top surface 220 of the edge ring 140a.

[0026]

[0032] FIG 2B illustrates a second embodiment of an edge ring assembly 138b. The second edge ring assembly 138b includes a second edge ring 140b and an overhang ring 112, such as the overhang ring 112 shown in FIG 1, disposed in a groove 306. The edge ring assembly 138b can also be used in the processing chamber 100 of FIG 1. The second edge ring 140b in FIG 2B is one continuous edge ring.

[0027]

[0033] The second edge ring 140b includes a groove 306 formed in an upper surface of the body 250b. The groove 306 is sized to receive the overhang ring 112. The outer body 202 has a bottom surface 240. The bottom surface 240 is adjacent to an upper surface of the electrostatic chuck 110. The bottom surface 240 includes a stepped region 242. The stepped region 242 corresponds to and engages with a similar stepped portion of the electrostatic chuck 110. The outer body 202 further includes a cantilever 208. The cantilever 208 is the radially innermost portion of the edge ring 140b. The cantilever 208 is disposed adjacent to the substrate support surface 230 of the electrostatic chuck 110. The cantilever 208 has an upper cantilever surface 232 that is parallel to the substrate support surface 230. The upper cantilever surface 232 may be substantially coplanar with the substrate support surface 230. In some embodiments, the upper cantilever surface 232 is utilized to protect the underside of an edge of a substrate, such as substrate 126. The edge of substrate 126 may extend over at least a portion of the cantilever 208.

[0028]

[0034] A vertical protrusion 206 is disposed on the top of the outer body of the second edge ring 140b. The vertical protrusion 206 has an inner protrusion surface 216. The inner protrusion surface 216 intersects with an upper cantilever surface 232 of the cantilever 208. A plurality of vertical protrusions 206 may be disposed on the upper cantilever surface 232. The plurality of vertical protrusions 206 are evenly distributed around the second edge ring 140b.

[0029]

[0035] The groove 306 of the edge ring 140b is disposed radially outward of the cantilever 208 relative to the central axis of the edge ring 140b. The groove 306 is disposed radially outward of the vertical protrusion 206. The groove 306 is sized to receive the overhang ring 112. The groove 306 has an inner sidewall 254, an outer sidewall 252, and a bottom surface 256. The outer and inner sidewalls 252, 254 are vertical sidewalls and are parallel to each other while being perpendicular to the bottom surface 256. The outer and inner sidewalls 252, 254 are spaced apart from each other by less than about 25 mm, e.g., less than about 20 mm, e.g., less than about 15 mm. In some embodiments, the outer and inner sidewalls 252, 254 are spaced apart from each other by a distance equal to the width of the first portion 210 of the overhang ring 112. The outer and inner sidewalls 252, 254 are parallel to one another and form concentric circles about the central axis of the edge ring 138b. The outer and inner sidewalls 252, 254 are connected by a bottom surface 256.

[0030]

[0036] The overhang ring 112 includes a first portion 210 and a second portion 270. The first portion 210 extends in an upward direction from the groove 306. In some embodiments, the first portion 210 is a vertical portion and extends vertically from the groove 306 of the second edge ring 140b. The height H2 of the first portion 210 is about 20 mm to about 40 mm, such as about 20 mm to about 35 mm, such as about 25 mm to about 30 mm. The second portion 270 extends radially inward toward the central axis of the edge ring 138b. The second portion 270 is disposed at an angle relative to the first portion 210. In the embodiment shown in FIG. 2B, the second portion 270 is a horizontal portion and is perpendicular to the first portion 210 of the overhang ring 112. The second portion 270 is disposed at a distal end of the first portion 210.

[0031]

[0037] The second portion is disposed over the first portion 210 and has a thickness of about 2 mm to about 8 mm, such as about 3 mm to about 7 mm, such as about 4 mm to about 6 mm, such as about 4.5 mm to about 5.5 mm.

[0032]

[0038] The second portion may be located at a height H2 from the bottom of the groove 306. The second portion may be further defined as being at a height H3 from the top of the vertical protrusion 206. The height H3 is from about 10 mm to about 30 mm, such as from about 15 mm to about 25 mm, such as from about 17.5 mm to about 22.5 mm, etc. In some embodiments, the height H3 is from about 18 mm to about 20 mm.

[0033]

[0039] It is contemplated that embodiments are possible in which the first portion 210 is not a vertical portion or the second portion 270 is not a horizontal portion. In embodiments in which the first portion 210 is not a vertical portion or the second portion 270 is not a horizontal portion, the angle between the first and second portions 210, 270 may vary.

[0034]

[0040] The first portion 210 and the second portion 270 of the overhang ring 112 are contiguous with one another. In some embodiments, the first portion 210 and the second portion 270 are formed entirely from a continuous piece of quartz.

[0035]

[0041] The inner overhang surface 214 is a radially inner edge of the second (e.g., horizontal) portion 270. The inner overhang surface 214 is disposed above the protrusion inner surface 216 such that the second portion 270 of the overhang ring 112 extends at least partially over the vertical protrusion 206. In some embodiments, the inner overhang surface 214 can have a similar radial position as the protrusion inner surface 216, e.g., within ±10 millimeters. In some embodiments, the inner overhang surface 214 extends only over a portion of the vertical protrusion 206, and the inner overhang surface 214 is disposed radially outward of the protrusion inner surface 216. The inner overhang surface 214 has an inner radius that is smaller than the inner radius of the edge ring 140b such that the inner overhang surface 214 does not extend over a substrate, such as the substrate 126, allowing placement of a substrate within the central opening of the edge ring 138b.

[0036]

[0042] In the embodiments described herein, both edge rings 140a, 140b and overhang ring 112 are entirely of a quartz material, such as silicon oxide (e.g., SiO2). Each of edge rings 140a, 140b and overhang ring 112 may be made entirely of quartz. In some embodiments, only a portion of edge rings 140a, 140b and overhang ring 112 are of a quartz material, although other materials may also be utilized.

[0037]

[0043] The first and second embodiments of the edge ring assemblies 138a, 138b may share some components not explicitly described herein. For example, the first and second embodiments of the edge ring assemblies 138a, 138b include a similar outer body 202, vertical protrusion 206, cantilever 208, bottom surface 240, and step region 242.

[0038]

[0044] FIG 3A is a schematic plan view of the edge ring 140b of FIG 2B. FIG 3B is a schematic cross-sectional view of the edge ring 140b of FIG 2B. The edge ring 140b includes a central opening 302, an outer body 202, a plurality of vertical protrusions 206, a groove 306, an upper cantilever surface 232, an intermediate surface 316, and an outer ledge surface 308.

[0039]

[0045] The opening 302 is circular and formed through the center of the edge ring 140b. In some embodiments, the diameter of the opening 302 is about 295 mm to about 300 mm, such as about 296 mm to about 298 mm, such as about 297 mm to about 298 mm. The diameter of the opening 302 is slightly smaller than the diameter of the substrate being processed, so that the cantilever 208 is positioned slightly below the substrate to protect the backside of the substrate.

[0040]

[0046] The upper cantilever surface 232 is disposed radially outward from the opening 302 such that the upper cantilever surface 232 is the surface between the inner cantilever surface 310 and the intermediate surface 316 of the edge ring 140b. The outer edge of the upper cantilever surface 232 has a diameter of about 315 mm to about 335 mm, such as about 320 mm to about 330 mm, such as about 322 mm to about 328 mm. The upper cantilever surface 232 is a horizontal surface and is planar.

[0041]

[0047] The plurality of vertical protrusions 206 are formed on the upper cantilever surface 232. In some embodiments, the plurality of vertical protrusions 206 are disposed on an outer portion of the upper cantilever surface 232. The inner protrusion inner surface has an inner diameter of about 300 mm to about 315 mm, such as about 300 mm to about 310 mm, such as about 302 mm to about 310 mm, such as about 302 mm to about 308 mm. The plurality of vertical protrusions 206 has a protrusion outer surface 502. The protrusion outer surface has a diameter of about 315 mm to about 335 mm, such as about 320 mm to about 330 mm. The plurality of vertical protrusions 206 includes six protrusions. In some embodiments, the number of vertical protrusions 206 can be 3 protrusions to 12 protrusions, such as 3 protrusions to 10 protrusions, such as 4 protrusions to 9 protrusions, such as 4 protrusions to 8 protrusions. The vertical protrusions are equally spaced about the central axis 1 and equidistant from one another around the upper cantilever face 232. The plurality of vertical protrusions 206 may have a width W of about 5 mm to about 25 mm, such as about 5 mm to about 20 mm, such as about 10 mm to about 15 mm. The width W is the distance across the face of the vertical protrusion 206 facing the central axis 1, and the vertical protrusions 206 facilitate fixation and alignment of the substrate during processing.

[0042]

[0048] Intermediate surface 316 is the surface between upper cantilever surface 232 and groove 306. Intermediate surface 316 is an angled surface such that intermediate surface 316 slopes downward as the radial distance from central axis 1 increases.

[0043]

[0049] The groove 306 is disposed between the intermediate surface 316 and the outer body 202. The groove 306 has two side walls 252, 254. The inner side wall 254 is adjacently connected to the intermediate surface 316. The outer side wall 252 is adjacently connected to the outer body 202. The inner side wall 254 of the groove 306 has a diameter of about 325 mm to about 350 mm, such as about 330 mm to about 350 mm, such as about 335 mm to about 345 mm. The outer side wall 252 of the groove 306 has a diameter of about 340 mm to about 360 mm, such as about 345 mm to about 355 mm. The groove 306 is formed around the entire circumference of the edge ring 140b.

[0044]

[0050] In some embodiments, the groove 306 may be a discontinuous groove. In this embodiment, the overhang ring 112 has a first portion 210 that fits into the discontinuous groove. Alternatively, the overhang ring 112 and the edge ring 140b may be adapted to attach the overhang ring 112 and the edge ring 140b using fasteners, sonic welding, or adhesives. The edge ring 140b and the overhang ring 112 may also be one continuous component or part. This embodiment may utilize three-dimensional printing or molding to form the overhang ring 112 and the edge ring 140b.

[0045]

[0051] The outer body 202 has an outer ledge surface 308. The outer ledge surface 308 is the outermost surface of the edge ring 140b. The outer ledge surface 308 may be a vertical surface and may be part of the outer body 202. The outer ledge surface 308 of the edge ring 140b has a diameter of about 375 mm to about 425 mm, such as about 380 mm to about 415 mm, such as about 385 mm to about 405 mm, such as about 390 mm to about 400 mm.

[0046]

[0052] Figure 3B is a cross-sectional side view of edge ring 140b. Edge ring 140b includes an opening 302, an outer body 202, a plurality of vertical protrusions 206, a groove 306, an inner cantilever surface 310, and an outer ledge surface 308. The cross-sectional view of Figure 3B is taken along the dotted line shown in Figure 3A.

[0047]

[0053] Edge ring 140b includes a central axis that is coaxial with central axis 1 when edge ring 140b is positioned in process chamber 100 of FIG.

[0048]

[0054] 4 is a cross-sectional side view of an overhang ring 112 for use with the edge ring 140b of FIGS. 3A-3B. The overhang ring 112 includes a first portion 210 and a second portion 270. The overhang ring is inserted into a groove 306 in the edge ring 140b. The overhang ring 112 is also centered along a central axis 1. In some embodiments, the central axis is the central axis 1 of the edge ring 140b or the central axis 1 of the overhang ring 112. An opening 302 is formed in the overhang ring 112 such that the central axis 1 passes through the opening 302.

[0049]

[0055] The first portion 210 includes an inner surface 408 and an outer surface 412. The inner surface 408 and the outer surface 412 are connected at one end by a bottom surface 410. The inner surface 408 and the outer surface 412 are both vertical surfaces such that the inner surface 408 and the outer surface 412 of the first portion 210 extend upwardly. The inner surface 408 and the outer surface 412 are parallel to one another. The inner surface 408 and the outer surface 412 extend in a similar upward direction from the bottom surface 410.

[0050]

[0056] The inner surface 408 has a diameter of about 325 mm to about 350 mm, such as about 330 mm to about 350 mm, such as about 335 mm to about 345 mm. The outer surface 412 has a diameter of about 335 mm to about 365 mm, such as about 340 mm to about 360 mm, such as about 345 mm to about 355 mm.

[0051]

[0057] The second portion 270 includes a lower surface 406, an upper surface 404, an inner overhang surface 214, and an outer surface 412. The lower surface 406 of the second portion 270 intersects and connects with the inner surface 408 of the first portion 210. The outer surface 412 extends from the first portion 210 to the second portion 270 and forms the outer surface 412 of the second portion 270. The upper surface 404 intersects and connects with the outer surface 412. The upper surface is the upper surface of the overhang ring 112. The inner overhang surface 214 is the innermost surface of the overhang ring 112. The inner overhang surface 214 intersects and connects with the lower surface 406 and the upper surface 404 of the second portion 270 of the overhang ring 112.

[0052]

[0058] The inner overhanging surface 214 is parallel to the inner surface 408 and the outer surface 412 of the first portion 210. The inner overhanging surface 214 has a diameter of about 300 mm to about 315 mm, such as about 300 mm to about 310 mm, such as about 302 mm to about 310 mm, such as about 302 mm to about 308 mm, such as about 303 mm to about 306 mm. The inner overhanging surface 214 may be sized such that a substrate having a diameter of 300 mm can pass through the opening 302 between the inner overhanging surfaces 214.

[0053]

[0059] The upper surface 404 of the second portion 270 of the overhang ring 112 and the lower surface 406 of the second portion 270 of the overhang ring 112 are parallel. The perpendicular between the upper surface 404 and the second portion 270 is about 2.5 mm to about 7.5 mm, such as about 3 mm to about 7 mm, such as about 3.5 mm to about 6.5 mm, such as about 4 mm to about 6 mm. The perpendicular represents the thickness of the second portion 270. The inner overhang surface 214 has a length of about 2.5 mm to about 7.5 mm, such as about 3 mm to about 7 mm, such as about 3.5 mm to about 6.5 mm, such as about 4 mm to about 6 mm.

[0054]

[0060] The upper surface 404 and the lower surface 406 of the second portion 270 of the overhang ring 112 may be perpendicular to the inner overhang surface 214 and the outer surface 412. The upper surface 404 and the lower surface 406 of the second portion 270 of the overhang ring 112 extend radially inward from the first portion 210 of the overhang ring 112. The lower surface 406 of the second portion 270 of the overhang ring 112 is smaller than the upper surface 404 of the second portion 270 of the overhang ring 112, such that the surface area of ​​the lower surface 406 is smaller than the surface area of ​​the upper surface 404.

[0055]

[0061] The underside 406 of the second portion 270 of the overhang ring 112 and the inside surface 408 of the first portion 210 of the overhang ring 112 intersect at a first corner 412. The first corner 412 is an inside corner of the overhang ring 112 and has an angle of about 80 degrees to about 100 degrees, such as about 85 degrees to about 95 degrees, such as about 90 degrees. The first corner 412 is a rounded corner or a beveled corner. The curve of the first corner 412 can have a radius of curvature of about 1.5 mm to about 4 mm, such as about 2 mm to about 3.5 mm, such as about 2 mm to about 3 mm.

[0056]

[0062] The top surface 404 of the second portion 270 of the overhang ring 112 and the outer surface 412 of the overhang ring intersect at a second corner 414. The second corner 414 is an outer corner of the overhang ring 112 and has an outer angle of about 260 degrees to about 280 degrees, such as about 265 degrees to about 275 degrees, such as about 270 degrees. The second corner 414 is a rounded corner or a beveled corner. The curve of the second corner 414 has a radius of curvature of about 0.5 mm to about 2 mm, such as about 1 mm to about 1.5 mm.

[0057]

[0063] The intersection of bottom surface 410 with outer surface 412 and inner surface 408 forms a bottom corner 416. Bottom corner 416 has a radius of curvature of about 0.5 mm to about 2 mm, e.g., about 1 mm to about 1.5 mm. The bottom corner has an outside angle of about 260 degrees to about 280 degrees, e.g., about 265 degrees to about 275 degrees, e.g., about 270 degrees.

[0058]

[0064] Figures 5A-5B are partial cross-sectional views of edge ring 140b of Figures 3A-3B. Figure 5A is a detailed view showing one side of the cross-sectional side view of Figure 3B. Figure 5B is a detailed view showing protrusion inner surface 216 shown in Figure 5A.

[0059]

[0065] 5A includes the inner cantilever surface 310, the cantilever 208, the vertical protrusion 206, the mid-surface 316, the groove 306, the outer body 202, the outer ledge surface 308, the bottom surface 240, and the step region 242. The edge ring 140b is a single piece and is disposed around the electrostatic chuck 110 and the substrate 126.

[0060]

[0066] The cantilever 208 is disposed adjacent to the inner cantilever surface 310 of the edge ring 140b. The inner cantilever surface 310 is the innermost portion of the edge ring 140b. The top cantilever surface 232 is the top surface of the cantilever 208. The inner cantilever surface 310 is the inside surface of the cantilever 208.

[0061]

[0067] The upper protruding surface 530 of the cantilever 208 intersects with the protruding inner surface 216 of the vertical protruding portion 206. The protruding inner surface 216 extends from the upper cantilever surface 232 to the upper protruding surface 530. The protruding inner surface 216 is an angled surface, being at an angle of greater than 90 degrees with respect to the upper cantilever surface 232. The upper protruding surface 530 is a horizontal surface. The upper protruding surface 530 extends from the protruding inner surface 216 to the protruding outer surface 502. The protruding outer surface 502 is a vertical surface. The protruding outer surface extends from the upper protruding surface 530 to the mid-surface 316. The protruding outer surface 502 is bounded at one end by the upper protruding surface 530 and at the other end by the mid-surface 316.

[0062]

[0068] The intermediate surface 316 extends from the protrusion outer surface 502 to the groove 306. More specifically, the intermediate surface 316 extends from a lower end of the protrusion outer surface 502 to an upper end of the inner sidewall 254 of the groove 306. The intermediate surface 316 is angled such that the intermediate surface 316 slopes downward as the radial distance from the central axis 1 increases. The intermediate surface 316 may be angled from about 5 degrees to about 15 degrees relative to the upper cantilever surface 232, such as from about 7.5 degrees to about 12.5 degrees, such as from about 9 degrees to about 11 degrees.

[0063]

[0069] The groove 306 is disposed between the intermediate surface 316 and the outer body 202. The groove 306 has two side walls 252, 254. The inner side wall 254 is adjacent to and connected to the intermediate surface 316. The outer side wall 252 is adjacent to and connected to the outer body 202. The inner side wall 254 and the outer side wall 252 are vertical side walls. The inner side wall 254 and the outer side wall 252 are connected by a bottom surface 256 of the groove 306. The bottom surface 256 of the groove 306 is a horizontal surface. The bottom surface 256 of the groove 306 is about 1 mm to about 5 mm below the inner bottom surface 522, for example, 1.5 mm to about 4 mm below the inner bottom surface 522, for example, about 2 mm to about 3 mm below the inner bottom surface 522, or about 2.25 mm to 2.75 mm below the inner bottom surface 522.

[0064]

[0070] The inner sidewall 254 is larger than the outer sidewall 252 within the groove 306. The outer sidewall 252 is smaller than the inner sidewall 254 due to the intermediate surface 316 and the slope of the outer body 202. The bottom surface 256 of the groove is sized to receive the bottom surface 410 of the overhang ring 112.

[0065]

[0071] The outer body 202 includes an inner major surface 508, an outer curved portion 510, and an outer ledge surface 308. The inner major surface 508 is coplanar with the intermediate surface 316 such that the outer body 202 has a surface that is at an angle of about 5 degrees to about 15 degrees relative to the upper cantilever surface 232, such as an angle of about 7.5 degrees to about 12.5 degrees, such as an angle of about 9 degrees to about 11 degrees.

[0066]

[0072] The outer ledge surface 308 of the outer body 202 is the outermost surface of the edge ring 140b. The outer ledge surface 308 of the outer body 202 is connected to the inner major surface 508 by an outer curved portion 510. The outer curved portion 510 connects the outer edge of the inner major surface 508 to the top edge of the outer ledge surface 308. The outer curved portion has a radius of curvature of about 3 mm to about 10 mm, such as about 4 mm to about 9 mm, such as about 5 mm to about 8 mm, such as about 6 mm to about 7 mm. The outer ledge surface 308 of the outer body 202 extends downward to protect the outer edge of the electrostatic chuck 110 (shown in FIGS. 2A-2B).

[0067]

[0073] The outer ledge surface 308 of the outer body 202 is connected to a ledge bottom surface 514. The ledge bottom surface 514 is a horizontal surface. The ledge bottom surface 514 connects the outer ledge surface 308 to an inner ledge surface 516. The ledge bottom surface 514 is connected to the outer ledge surface 308 and the inner ledge surface 516 at curved corners. The curved corners between the outer ledge surface 308 and the ledge bottom surface 514 and between the inner ledge surface 516 and the ledge bottom surface 514 have a radius of curvature of about 0.5 mm to about 2.5 mm, such as about 0.75 mm to about 2 mm, such as about 1 mm to about 1.5 mm.

[0068]

[0074] The inner ledge surface 516 is a vertical surface and is parallel to the outer ledge surface 308. The inner ledge surface 516 is sized to surround the outer surface of the electrostatic chuck. The inner ledge surface 516 is a portion of the bottom surface 240 of the edge ring 140b. The inner ledge surface 516 has a first end connected to the ledge bottom surface 514 and a second end connected to the primary bottom surface 518.

[0069]

[0075] The primary bottom surface 518 is a horizontal surface. The primary bottom surface 518 is a planar surface and extends from the inner ledge surface 516 to a lower step surface 520. The lower step surface 520 is a vertical surface that is part of the step region 242. The lower step surface 520 is radially inward of the inner ledge surface 516 and the primary bottom surface 518. The lower step surface 520 is also radially inward of the groove 306. The lower step surface 520 connects the primary bottom surface 518 to the inner bottom surface 522.

[0070]

[0076] The inner bottom surface 522 is a horizontal surface that connects the lower step surface 520 to the inner cantilever surface 310. The inner bottom surface 522 is below the vertical protrusion 206 and the cantilever 208. The inner bottom surface 522 is a flat surface. The inner bottom surface 522 is part of the step region 242.

[0071]

[0077] 5B is a detailed view of the protrusion inner surface 216. The protrusion inner surface 216 includes a first inner protruding surface 528 and a second inner protruding surface 532. The protrusion inner surface 216 is a curved inner surface. The radius of curvature of the protrusion inner surface 216 is about 150 mm to about 165 mm, such as about 150 mm to about 160 mm, such as about 152 mm to about 158 ​​mm, such as about 154 mm to about 156 mm. The first inner protruding surface 528 is a vertical surface extending from the upper cantilever surface 232 of the cantilever 208. The first inner protruding surface 528 is connected to the upper cantilever surface 232 at a first protruding corner 526. The first protruding corner 526 is a curved corner and may have a radius of curvature of about 1 mm to about 5 mm, such as about 2 mm to about 4 mm. The first inwardly protruding surface 528 has a height H3 of about 1 mm to about 5 mm, such as about 2 mm to about 4 mm, such as about 2.5 mm to about 3.5 mm.

[0072]

[0078] The second inwardly projecting surface 532 is disposed adjacent to the first inwardly projecting surface 528 and is connected to the first inwardly projecting surface 528 at a second projecting corner 524. The second inwardly projecting surface 532 is a positively sloped surface as the distance from the central axis increases. The second inwardly projecting surface 532 is offset from the vertical by an angle θ such that the angle θ is about 5 degrees to about 20 degrees, such as about 7 degrees to about 15 degrees, such as about 9 degrees to about 12 degrees.

[0073]

[0079] The second inner protruding surface 532 has a height H4. The height H4 of the second inner protruding surface 532 is about 1 mm to about 4 mm, such as about 1.5 mm to about 3 mm, such as about 2 mm to about 2.5 mm. The second inner protruding surface 532 is connected to the upper protruding surface 530 at a third protruding corner 520. The third protruding corner 520 is a curved corner and has a radius of curvature of about 0.1 mm to about 0.5 mm, such as about 0.2 mm to about 0.4 mm, such as about 0.25 mm to about 0.35 mm.

[0074]

[0080] 6 is a graph showing film thickness on a substrate after using two different edge rings during a SiO2 process, such as a SiO2 oxidation process. The first edge ring is a standard edge ring, which has poor thickness uniformity near the edge of the substrate (shown as a solid line). The second edge ring is an edge ring that utilizes an overhang feature, such as edge ring 140b described herein, which has improved thickness uniformity near the edge of the substrate.

[0075]

[0081] FIG. 6 illustrates the significantly improved layer thickness near the edge of the substrate. The improved layer thickness is caused, at least in part, by a change in the direct RF current transmission path between the substrate and the sidewall of the process chamber, such as RF current line 124 in FIG. 1. In conventional substrate processing processes with high bias to source power ratios, the plasma density and the plasma current to the substrate are affected. The effect on the plasma current and plasma density results in a thicker film toward the edge of the substrate. The cause of the thicker film toward the edge of the substrate is the direct RF transmission between the substrate and the grounded sidewall, without the passage of a plasma controlled by a source power coil.

[0076]

[0082] It has been found that utilizing an edge ring with an overhanging ring produces greater uniformity and redirects the direct RF transmission line through the denser plasma created by the source power coil, as shown in Figure 6. The RF current lines 124 are redirected through the plasma, such as the first plasma region and the second plasma region.

[0077]

[0083] The overhang ring reroutes the RF current lines 124 through a region having a higher plasma density than would be achieved using a conventional edge ring. The second portion 210 of the overhang ring 112 pushes the RF current lines 124 inward through a region of higher plasma density, and the ion current to the substrate near the edge is not significantly changed because the first portion 210 of the overhang ring 112 is not located immediately next to the edge of the substrate.

[0078]

[0084] Although edge rings 140a, 140b and overhang ring 112 are both described herein as being a quartz material, it is contemplated that other materials may be used within edge ring 140 and / or overhang ring 112. Other materials that may be part of edge ring 140a, 140b and overhang ring 112 include silicon carbide, alumina, or yttria. In some embodiments, other ceramic materials are utilized. In some embodiments, the quartz material may include additional materials embedded therein.

[0079]

[0085] Although some corners of edge rings 140a, 140b and overhang ring 112 are described above as being rounded corners, it is contemplated that all corners of edge rings 140a, 140b and overhang ring 112 may be rounded corners. Unless otherwise noted above, all corners of edge rings 140a, 140b and overhang ring 112 may each be rounded corners having a radius of curvature of less than about 1 mm, e.g., less than about 0.75 mm, e.g., less than about 0.5 mm. In an alternative embodiment, all corners of edge rings 140a, 140b and overhang ring 112 may be sharp corners.

[0080]

[0086] In some embodiments, the edge ring 140a of FIG. 2A is utilized. In this embodiment, an apparatus for processing a substrate includes an edge ring. The edge ring includes a bottom surface and a top surface. The top surface further includes a cantilever, an extending body, and an outer body. The cantilever is disposed radially inward of the extending body, and the extending body is disposed radially inward of the outer body. The extending body includes an inner surface, an outer surface, and a top surface. The top surface includes a vertical protrusion disposed thereon, and the extending body has a height of about 10 mm to about 40 mm.

[0081]

[0087] Although the embodiments herein have generally been described in terms of dimensions for processing 300 mm substrates, it is contemplated that substrates of other dimensions may also be processed, and in such implementations, the dimensions of the edge ring described herein may be scaled accordingly.

[0082]

[0088] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof, as determined by the following claims.

Claims

1. 1. An apparatus for processing a substrate, comprising: An edge ring, The bottom surface and The top surface and a groove disposed on the upper surface; an edge ring including an overhang ring disposed in the groove, further comprising: a first portion extending from the groove; a second portion connected to the first portion and extending radially inward; Overhanging ring including An apparatus comprising:

2. The apparatus of claim 1 , wherein the edge ring comprises a quartz material.

3. The apparatus of claim 1 , wherein the overhang ring comprises a quartz material.

4. The apparatus of claim 1 , wherein the edge ring further comprises a plurality of tabs disposed on the upper surface.

5. The device of claim 4 , wherein the plurality of tabs comprises between 3 and 10 tabs.

6. The apparatus of claim 4 , wherein the plurality of tabs are disposed radially inward of the groove.

7. The apparatus of claim 4 , wherein the second portion of the overhang ring extends radially inward of an outer surface of the plurality of tabs.

8. The apparatus of claim 1 , wherein the edge ring further comprises an outer ledge, the outer ledge extending from a bottom surface of the edge ring.

9. The apparatus of claim 1 , wherein the second portion of the overhang ring is perpendicular to the first portion of the overhang ring.

10. The apparatus of claim 1 , wherein the overhang ring has an inner radius that is smaller than an inner radius of the edge ring.

11. The apparatus of claim 1 , wherein the edge ring groove has a sidewall sized to receive the first portion of the overhang ring.

12. 1. An apparatus for processing a substrate, comprising: An edge ring, The bottom surface and The top surface and A central opening; a groove disposed on the upper surface; an edge ring including an overhang ring disposed in the groove, further comprising: a first portion extending upwardly from the groove; a second portion extending radially inward toward a central axis of the overhang ring; Overhanging ring including An apparatus comprising:

13. The apparatus of claim 12 , wherein the overhang ring has an inner radius that is smaller than an inner radius of the edge ring.

14. The bottom surface further comprises: The inner bottom surface, a lower step surface connected to an outer edge of the inner bottom surface; a primary bottom surface connected to an end portion of the lower step surface opposite to the inner bottom surface; an inner ledge surface connected to an outer edge of the primary bottom surface; The apparatus of claim 12 , comprising:

15. 15. The apparatus of claim 14, wherein the bottom surface of the groove is disposed vertically about 1 mm to about 5 mm from the inner bottom surface.

16. 15. The apparatus of claim 14, wherein the second portion is about 10 mm to about 30 mm from a bottom surface of the groove.

17. The device of claim 12, wherein the groove has a width of less than about 15 mm.

18. 1. An apparatus for processing a substrate, comprising: An edge ring, further comprising: A support surface; The top surface and A groove disposed on the upper surface; a plurality of tabs disposed on the top surface; an edge ring including an overhang ring disposed in the groove, further comprising: a first portion extending from the groove; a second portion connected to the first portion and extending radially inward; Overhanging ring including An apparatus comprising:

19. 20. The apparatus of claim 18, wherein the edge ring and the overhang ring comprise a quartz material.

20. 20. The apparatus of claim 18, wherein the groove is approximately the same width as the first portion of the overhang ring.

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