MOVABLE EDGE RING WITH REDUCED CAPACITANCE VARIATION FOR SUBSTRATE PROCESSING SYSTEM - Patent application

Abstract

A movable edge ring system with reduced capacitance variation for a substrate processing system is provided. A movable edge ring system for a plasma processing system includes an upper edge ring (810), a first edge ring (820) disposed below the upper edge ring, and a second edge ring (840). The second edge ring is made of a conductive material and includes an upper portion (828), a middle portion (822), and a lower portion (824). The upper and second edge rings move vertically relative to a substrate support (126) and the first edge ring when urged upward by lift pins (870). The second edge ring is disposed below the upper edge ring and radially outward of the first edge ring.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 62 / 976,088, filed February 13, 2020, and U.S. Provisional Application No. 62 / 882,890, filed August 5, 2019. The entire disclosures of the above-referenced applications are incorporated herein by reference.

[0002] The present disclosure relates generally to plasma processing systems, and more particularly to an edge ring system that includes a movable edge ring. [Background technology]

[0003] The background description provided herein is intended to provide a general overview of the contents of the present disclosure. Work by the currently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise be regarded as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure.

[0004] Substrate processing systems perform processes on substrates, such as semiconductor wafers. Examples of substrate processing include deposition, ashing, etching, cleaning, and / or other processes. A process gas mixture may be supplied to the processing chamber to process the substrate. A plasma may be used to ignite the gases and drive chemical reactions.

[0005] The substrate is disposed on a substrate support during processing. The edge ring is annular and disposed adjacently around a radially outer edge of the substrate. The edge ring can be used to shape or focus a plasma onto the substrate. During operation, exposed surfaces of the substrate and edge ring are etched by the plasma. As a result, the edge ring wears and the effect of the edge ring on the plasma changes over time. Summary of the Invention

[0006] A movable edge ring system for a plasma processing system includes an upper edge ring and a first edge ring disposed below the upper edge ring. The second edge ring is made of a conductive material and includes an upper portion, a middle portion, and a lower portion. The upper edge ring and the second edge ring are configured to move vertically relative to the substrate support and the first edge ring when urged upward by lift pins. The second edge ring is disposed below the upper edge ring and radially outward of the first edge ring.

[0007] In other features, the lower portion of the second edge ring extends radially inward relative to the intermediate portion and defines a first gap between the lower portion of the second edge ring and the radially outer surface of the substrate support. The intermediate portion of the second edge ring defines a second gap between the intermediate portion and the radially outer surface of the substrate support. The second gap is at least twice the first gap.

[0008] In other features, an intermediate portion of the second edge ring moves parallel to a radially outer edge of the first edge ring as the lift pins raise the second edge ring and the upper edge ring. The upper edge ring has an inverted "U" shape. The upper edge ring is made of a conductive material. The upper edge ring is made of a dielectric material. The first edge ring is made of a conductive material. The first edge ring is made of a dielectric material. The intermediate portion of the second edge ring extends radially inward relative to an upper portion of the second edge ring and defines a first annular recess.

[0009] In other features, the first edge ring includes a second annular recess on its upper and radially outer surfaces. A radially inner leg of the upper edge ring lies in the first annular recess and in the second annular recess when the upper edge ring is in the lowered position.

[0010] In other features, a third edge ring is located below and radially outward of the first edge ring, the second edge ring, and the upper edge ring. The third edge ring defines an annular recess on its upper and radially inner surface. A radially outer leg of the upper edge ring lies in the annular recess when the upper edge ring is in the lowered position.

[0011] In other features, the third edge ring includes vertical bores for receiving the lift pins.The second edge ring has a generally rectangular cross-section and a radially inner surface parallel to a radially outer edge of the substrate support.

[0012] A movable edge ring system for a plasma processing system includes an upper edge ring. A first edge ring is made of a dielectric material and includes an embedded conductor fully embedded within the dielectric material. The first edge ring underlies the upper edge ring. The upper edge ring and the first edge ring are configured to move vertically relative to the substrate support when urged upward by lift pins.

[0013] In other features, the second edge ring is disposed below the upper edge ring. The first edge ring includes an upper portion, a middle portion, and a lower portion. The first edge ring is disposed below the upper edge ring and radially outward of the second edge ring.

[0014] In other features, the lower portion of the first edge ring extends radially inward relative to the intermediate portion and defines a first gap between the lower portion of the second edge ring and the radially outer surface of the substrate support. The intermediate portion of the first edge ring defines a second gap between the intermediate portion and the radially outer surface of the substrate support. The second gap is greater than or equal to two times the first gap.

[0015] In other features, the intermediate portion of the first edge ring moves parallel to the radially outer edge of the second edge ring as the lift pins raise the first edge ring and the upper edge ring. The upper edge ring has an inverted "U" shape.

[0016] In other features, the embedded conductors include horizontal conductors disposed at an upper portion parallel to an upper surface of the first edge ring. The embedded conductors further include vertical conductors disposed at a lower portion parallel to a radially inner surface of the first edge ring. The embedded conductors further include a conductor connecting the vertical conductors and the horizontal conductor. The top edge ring is made of a conductive material. The top edge ring is made of a dielectric material. The second edge ring is made of a dielectric material. The second edge ring is made of a conductive material.

[0017] In other features, the first edge ring, the second edge ring, and a third edge ring located below and radially outward of the upper edge ring. The third edge ring defines an annular recess on its upper and radially inner surface. A radially outer leg of the upper edge ring lies in the annular recess when the upper edge ring is in a lowered position. The third edge ring includes a vertical bore for receiving a lift pin.

[0018] In other features, the first edge ring is fabricated from a ceramic green sheet including conductive traces and vias.

[0019] A movable edge ring system for a plasma processing system includes an upper edge ring. A first edge ring is fabricated from a dielectric material and includes a doped region and an undoped region. The doped region is more conductive than the undoped region. The first edge ring is below the upper edge ring. The upper edge ring and the first edge ring are configured to move vertically relative to the substrate support when urged upward by lift pins.

[0020] In other features, the second edge ring is disposed below the upper edge ring. The first edge ring includes an upper portion, a middle portion, and a lower portion. The first edge ring is disposed below the upper edge ring and radially outward of the second edge ring.

[0021] In other features, the lower portion of the first edge ring extends radially inward relative to the intermediate portion and defines a first gap between the lower portion of the second edge ring and the radially outer surface of the substrate support. The intermediate portion of the first edge ring defines a second gap between the intermediate portion and the radially outer surface of the substrate support. The second gap is greater than or equal to two times the first gap.

[0022] In other features, a middle portion of the first edge ring moves parallel to a radially outer edge of the second edge ring as the lift pins raise the first edge ring and the top edge ring. The doped regions are disposed along an upper surface and a radially inner surface of the first edge ring. The top edge ring has an inverted "U" shape. The top edge ring is made of a conductive material. The top edge ring is made of a dielectric material. The second edge ring is made of a conductive material. The second edge ring is made of a dielectric material.

[0023] In other features, a third edge ring is located below and radially outward of the first edge ring, the second edge ring, and the upper edge ring. The third edge ring defines an annular recess on its upper and radially inner surface. A radially outer leg of the upper edge ring lies in the annular recess when the upper edge ring is in the lowered position. The third edge ring includes vertical bores that receive lift pins.

[0024] An edge ring for a plasma processing system includes an annular body made of at least one of a dielectric material and a conductive material. The annular body includes an upper portion, a middle portion, and a lower portion. A first step projects radially outward from a radially inner surface of the annular body between the upper portion and the middle portion. A second step projects radially outward from a radially inner surface of the annular body between the middle portion and the lower portion.

[0025] In other features, the annular body further comprises an embedded conductor made of a dielectric material and disposed completely inside the annular body. The embedded conductor includes a horizontal conductor disposed at an upper portion parallel to an upper outer surface of the annular body. The embedded conductor further includes a vertical conductor disposed at a lower portion of the annular body parallel to a radially inner surface of the annular body. The embedded conductor further includes a conductor connecting the vertical conductor and the horizontal conductor. The annular body is made of a dielectric material and further comprises a doped region and an undoped region. The doped region of the annular body is more conductive than the undoped region. The doped region is disposed on the upper surface and the radially inner surface of the annular body. The annular body is made of a ceramic green sheet including conductive traces and vias.

[0026] The edge ring for a plasma processing system includes an annular body fabricated from a dielectric material and configured to surround a substrate support of the plasma processing system. The embedded conductor is disposed completely inside the annular body and includes a first conductor disposed in the annular body and a second conductor disposed in the annular body and connected to the first conductor across the first conductor.

[0027] In other features, the annular body has an "L" shaped cross section. The annular body includes a first leg connected to a second leg. A first conductor is disposed on the first leg and a second conductor is disposed on the second leg.

[0028] In other features, the first conductor is disposed parallel to a first outer surface of the annular body. The third conductor is disposed parallel to a second outer surface of the annular body. The second conductor is connected to the first conductor and the third conductor. The annular body includes an upper portion, a middle portion, and a lower portion. The first step is located on the radially inner surface of the annular body between the upper portion and the middle portion and projects radially outward therefrom. The second step is located on the radially inner surface of the annular body between the middle portion and the lower portion and projects radially outward therefrom.

[0029] In other features, a first conductor is disposed parallel to a first outer surface of the annular body in the upper portion. A second conductor is disposed parallel to a radially inner surface of the annular body in the lower portion. A third conductor connects the first conductor to the second conductor. The annular body is fabricated from a ceramic green sheet including conductive traces and vias.

[0030] An edge ring for a plasma processing system includes an annular body configured to surround a substrate support of the plasma processing system, wherein an embedded conductor is disposed within the annular body and configured to capacitively couple, but not directly couple, to at least one external conductive component selected from the group consisting of a base plate of the substrate support and another edge ring.

[0031] An edge ring for a plasma processing system includes an annular body made of a dielectric material and configured to be disposed around a substrate support, the annular body including a doped region and an undoped region, the doped region being more conductive than the undoped region.

[0032] In other features, the doped region includes a first portion disposed along a radially inner surface of the annular body. The doped region includes a second portion disposed on an upper surface of the annular body. The first portion is in contact with the second portion. The annular body includes an upper portion, a middle portion, and a lower portion. A first step is located on the radially inner surface of the annular body between the upper portion and the middle portion and projects radially outward therefrom. A second step is located on the radially inner surface of the annular body between the middle portion and the lower portion and projects radially outward therefrom.

[0033] In other features, the dielectric material comprises silicon carbide. The dielectric is doped with an impurity selected from the group consisting of boron, aluminum, or nitrogen.

[0034] A movable edge ring system for a plasma processing system includes an upper edge ring. A first edge ring is disposed below the upper edge ring and has a rectangular cross section. A second edge ring is made of a conductive material, has a Z-shaped cross section, and is disposed radially outward and above the first edge ring. The upper edge ring and the second edge ring are configured to move vertically relative to the first edge ring and the substrate support when biased by lift pins.

[0035] In other features, as the second edge ring moves upwardly along the first edge ring from the lowered position to the raised position, the second edge ring maintains a fixed surface area within a predetermined gap of the radially outer surface of the first edge ring, the remaining surface area of ​​the second edge ring being located at a distance greater than or equal to twice the predetermined gap from the first edge ring.

[0036] In other features, the second edge ring includes an annular body including an upper portion projecting radially inward, a vertically extending intermediate portion connected to the upper portion, a lower portion connected to a lower end of the intermediate portion and projecting radially outward, and a protrusion extending radially inward from the intermediate portion and extending downwardly to a lower edge of the lower portion.

[0037] In other features, the fixed surface area is defined by a protrusion. The third edge ring is located below the upper edge ring and radially inward of the first edge ring. The third edge ring has an "L" shaped cross section. The fourth edge ring is located radially outward of the upper edge ring and the second edge ring. The fourth edge ring includes a protrusion extending radially inward and disposed between portions of the upper edge ring and the second edge ring. The upper edge ring has an inverted "U" shape, a body, an inner leg, and an outer leg. When the upper edge ring is in the lowered position, it resides directly adjacent to the second edge ring, the third edge ring, and the fourth edge ring.

[0038] In other features, the top edge ring is made of a conductive material.The top edge ring is made of a dielectric material.The first edge ring is made of a conductive material.

[0039] A movable edge ring system for a plasma processing system includes a first edge ring fabricated from a conductive material and configured to surround a substrate support. The lift pins are fabricated from a conductive material. A lift pin actuator is configured to bias the lift pins against the first edge ring when in a lowered position and selectively move the lift pins to increase the height of the first edge ring relative to the substrate support while maintaining contact between the lift pins and the first edge ring.

[0040] In other features, a second edge ring is located radially inward and below the first edge ring, the second edge ring being fabricated from a dielectric material, the second edge ring having an "L" shaped cross section including a vertically extending radially inner leg and a horizontally extending radially outer leg.

[0041] In other features, a third edge ring is disposed radially outward and below the first edge ring and the second edge ring. The third edge ring is made of a dielectric material. The third edge ring has an "L" shaped cross section. The first edge ring has a rectangular cross section.

[0042] In other features, the third edge ring includes an annular body and a radially inwardly projecting portion including a vertical bore that receives a lift pin.

[0043] A movable edge ring system for a plasma processing system includes a first edge ring made of a dielectric material including embedded conductors disposed completely within the dielectric material and configured to surround a substrate support. The lift pins are made of a conductive material. The lift pin actuator is configured to bias the lift pins against the first edge ring when in a lowered position and selectively move the lift pins to increase the height of the first edge ring relative to the substrate support while maintaining contact between the lift pins and the first edge ring.

[0044] In other features, the buried conductors include a first horizontal conductor disposed parallel to a top surface of the first edge ring, a second horizontal conductor disposed parallel to a bottom surface of the first edge ring, and a third conductor connecting the first horizontal conductor to the second horizontal conductor.

[0045] In other features, a second edge ring is located radially inward and below the first edge ring, the second edge ring being made of a dielectric material, the second edge ring having an "L" shaped cross section including a vertically extending radially inner leg and a horizontally extending radially outer leg.

[0046] In other features, a third edge ring is located radially outward and below the first edge ring and the second edge ring. The third edge ring is made of a dielectric material. The third edge ring has an "L" shaped cross section. The first edge ring has a rectangular cross section. The third edge ring includes an annular body and a radially inwardly protruding portion including a vertical bore that receives a lift pin.

[0047] The movable edge ring system for a plasma processing system includes an upper edge ring having an inverted "U" shaped cross section and including an annular body, a radially inner leg, and a radially outer leg. The first edge ring is made of a conductive material and is disposed at least partially between the radially inner leg and the radially outer leg of the upper edge ring. The second edge ring is made of a dielectric material and is disposed between the first edge ring and the substrate support. The third edge ring is disposed below and radially outward of the first and second edge rings and includes N cavities for receiving N lift pins, where N is an integer greater than 2. The upper edge ring moves relative to the first edge ring, the second edge ring, the third edge ring, and the substrate support when energized by the N lift pins.

[0048] In other features, the second edge ring and the third edge ring are made of a dielectric material. The first edge ring has an "L" shaped cross section. The second edge ring has an "L" shaped cross section. The upper edge ring includes N radial recesses spaced 360° / N apart, the N radial recesses including an angled lower surface located on the radially inner surface of the radially outer leg and extending radially outward from the radial recesses. The N lift pins bias the upper edge ring in the N radial recesses as the height of the upper edge ring is adjusted.

[0049] An edge ring for a plasma processing system includes an annular body having an inverted "U" shaped cross section, a radially inner leg extending from the annular body, a radially outer leg extending from the annular body, N radial recesses spaced 360° / N apart, N being an integer greater than 2, located on a radially inner surface of the radially outer leg, and an angled lower surface extending radially outward from the N radial recesses.

[0050] The movable edge ring system includes an edge ring. The first edge ring has a "U" shaped cross section and includes an annular body, a radially inner leg, and a radially outer leg. The radially inner leg of the edge ring is located between the radially inner leg and the radially outer leg of the first edge ring. The second edge ring is disposed below and radially outward of the edge ring and the first edge ring and includes N vertical bores that receive the N lift pins. The edge ring moves relative to the first edge ring, the second edge ring, and the substrate support when energized by the N lift pins.

[0051] In other features, the first edge ring and the second edge ring are made of a dielectric material. The first edge ring has an "L" shaped cross section. The second edge ring has an "L" shaped cross section. The edge rings are configured to receive N lift pins in the N radial recesses when adjusting a height of the edge ring.

[0052] The movable edge ring system includes an edge ring. The first edge ring has an "L" shaped cross section and includes a radially inner leg and a vertical leg. The vertical leg of the first edge ring is located between the radially inner leg and the radially outer leg of the edge ring. The second edge ring is disposed radially inward from the first edge ring. The third edge ring is disposed below and radially outward from the edge ring. The first edge ring and the second edge ring include vertical bores that receive lift pins. The edge ring moves relative to the first edge ring, the second edge ring, the third edge ring, and the substrate support when biased by the lift pins.

[0053] The movable edge ring system for a plasma processing system includes an upper edge ring having an inverted "U" shaped cross section, including an annular body, a radially inner leg, and a radially outer leg. The first edge ring is made of a dielectric material and disposed completely inside the dielectric material, configured to surround a substrate support, and includes an embedded conductor disposed at least partially between the radially inner leg and the radially outer leg of the upper edge ring. The second edge ring is made of a dielectric material and disposed between the substrate support and the first edge ring. The third edge ring is disposed below and radially outward of the first edge ring and the second edge ring, and includes a vertical bore that receives a lift pin. The upper edge ring is movable relative to the first edge ring, the second edge ring, and the third edge ring when biased by the lift pin.

[0054] In other features, the second edge ring and the third edge ring are made of a dielectric material. The second edge ring has an "L" shaped cross section. The first edge ring has an "L" shaped cross section. The first edge ring includes an annular body with a vertical leg connected to a horizontal leg. The embedded conductor includes a vertical conductor disposed on the vertical leg and a horizontal conductor disposed on the horizontal leg in communication with the vertical conductor.

[0055] An edge ring for a plasma processing system includes an annular body, a radially inner leg connected to the annular body, and a radially outer leg connected to the annular body. A first portion of an upper surface of the annular body is parallel to a plane containing the substrate. A second portion of the upper surface of the annular body is sloped downwardly at an acute angle from the first portion.

[0056] In other features, the first portion of the upper surface is located radially inward of the second portion of the upper surface, and the third portion of the upper surface is parallel to a plane containing the substrate and is located radially outward of the second portion of the upper surface.

[0057] The movable edge ring system includes an edge ring, a first edge ring made of a conductive material, configured to surround the substrate support, and disposed at least partially between a radially inner leg and a radially outer leg of the edge ring.

[0058] In other features, the second edge ring is made of a dielectric material and is disposed between the first edge ring and the substrate support. The third edge ring is disposed below and radially outward of the first and second edge rings and includes vertical bores that receive the lift pins. The edge ring moves relative to the first edge ring, the second edge ring, and the substrate support when biased by the lift pins.

[0059] An edge ring for a plasma processing system includes an annular body with a rectangular cross-section, a radially inwardly projecting leg extending from a radially inner and upper surface of the annular body, and a radially inner portion of the upper surface of the annular body disposed parallel to a plane containing the substrate.

[0060] In other features, a radially outer portion of the upper surface of the annular body sloping downwardly at an acute angle from the radially inner portion.

[0061] A movable edge ring system for a plasma processing system includes an edge ring. A middle edge ring is disposed radially inward of the annular body below the radially inwardly protruding legs. An outer edge ring is disposed below the edge ring and the middle edge ring and includes vertical bores that receive lift pins. When the edge ring is actuated by the lift pins, it moves vertically relative to the middle and outer edge rings.

[0062] In other features, the intermediate edge ring has a generally rectangular cross-section and an annular recess on its radially inner and upper surfaces. The substrate is disposed in the annular recess. The outer edge ring includes a radially outer portion and an inner portion extending radially inward from a middle portion of the radially outer portion.

[0063] In other features, the outer edge ring includes a protrusion on an upper and radially inner surface of the inner portion. The protrusion resides adjacent a junction between the heating plate and the base plate of the substrate support. A bottom portion of the annular body is located adjacent the upper surface of the outer edge ring between the radially outer portion and the protrusion.

[0064] The plasma processing system includes a movable edge ring system. The substrate support includes a base plate. The heating plate is coupled to the base plate. The heating plate includes a body including a plurality of radio frequency (RF) electrodes, a cylindrical portion, and a protruding portion extending radially outward from the cylindrical portion below an intermediate edge ring.

[0065] In other features, the plurality of RF electrodes are not located on a portion of the protruding portion that is located below the intermediate edge ring.

[0066] A movable edge ring system for a plasma processing system includes an upper edge ring configured to surround a substrate support. The movable edge ring system includes an annular body, a radially outer leg projecting downward from a radially outer surface of the annular body, a radially inner leg projecting downward from a radially inner surface of the annular body, and an inwardly protruding leg extending radially inward from a lower end of the radially inner leg. The inwardly protruding leg is disposed below the substrate when the substrate is disposed on the substrate support. A first edge ring is configured to surround the substrate support and is disposed below the upper edge ring and includes an annular body and a radially inwardly protruding leg. An upper surface of the first edge ring is disposed between the radially inner leg and the radially outer leg of the upper edge ring when the first edge ring is biased against the upper edge ring.

[0067] In other features, the second edge ring is disposed radially outward of the upper edge ring and the first edge ring, the second edge ring including an annular body, radially outwardly projecting legs extending from upper and radially outer surfaces of the annular body, and radially inwardly projecting legs extending radially inward from radially inner and lower surfaces of the annular body.

[0068] In other features, the inwardly projecting legs of the first edge ring extend radially inward from an upper and radially inner surface of the annular body of the first edge ring. The third edge ring is disposed radially outward from the first edge ring and below the upper edge ring, the first edge ring, and the second edge ring. The third edge ring includes an annular body, a radially downwardly projecting leg extending from a radially outer and lower surface of the third edge ring, and an inwardly projecting leg extending radially inward from a middle portion of the third edge ring.

[0069] In other features, the inwardly protruding leg of the third edge ring includes a vertical bore for receiving a lift pin. When biased against the upper edge ring, the first edge ring defines a first vertical gap between a lower surface of the radially inner leg of the first edge ring and a surface of the substrate support, and a second vertical gap between the lower surface of the first edge ring and an upper surface of the inwardly protruding leg of the third edge ring.

[0070] In other features, when in the lowered position, the first edge ring abuts an inner leg of the third edge ring and protrudes to define a third vertical gap between an upper surface of the first edge ring and a lower surface of the upper edge ring.

[0071] The plasma processing system includes a processing chamber. A substrate support is disposed in the processing chamber. The processing chamber includes a substrate port. A robot arm delivers a substrate onto the substrate support. A movable edge ring system is disposed about the substrate support. Lift pins urge the upper edge ring and the first edge ring against the substrate support.

[0072] In other features, the first edge ring and the upper edge ring are raised relative to the substrate support by lift pins, a robot arm removes the upper edge ring, and the robot arm delivers another upper edge ring to the substrate support through the substrate port.

[0073] An edge ring system for a plasma processing system includes an upper ring including a first annular body configured to surround a substrate support during plasma processing. The lower ring includes a second annular body configured to surround a substrate support during plasma processing. At least a portion of the second annular body of the lower ring is nested relative to and within a portion of the first annular body of the upper ring when configured for plasma processing to define a predetermined gap. N spacers are disposed at N spaced apart locations on a surface of at least one of the upper and lower rings to reduce variation of the predetermined gap between the annular body of the upper and lower rings as the upper and lower rings are heated and cooled during plasma processing, N being an integer between 3 and 8 inclusive.

[0074] In other features, at least one of the N spacers includes a shim that is located in a slot on a radially facing surface of at least one of the upper and lower rings. The shim has a rectangular cross-section. The slot is located on a radially outer surface of the inner ring. At least one of the N spacers includes a pin that is located in a slot on a surface of at least one of the upper and lower rings. The slot is located on the radially outer surface of the inner ring. The N spacers are spaced 360° / N apart.

[0075] In other features, at least one of the N spacers includes a protrusion formed on a surface of at least one of the upper ring and the lower ring. The protrusion is located on a radially outer surface of the inner ring. A coating covers the protrusion. The coating includes an insulating material.

[0076] In other features, the coating is selected from the group consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA), aluminum oxide deposited using atomic layer deposition, yttrium oxide deposited using atomic layer deposition, and yttrium fluoride deposited using atomic layer deposition. In other features, N=5. The lift pins lift the upper ring relative to the lower ring and adjust the height of the top surface of the upper edge ring relative to the substrate on the substrate support.

[0077] An edge ring for a plasma processing system includes a first annular body configured to surround a substrate support during plasma processing. At least a portion of the first annular body is configured to nest within a portion of a second annular body of an upper ring exposed to plasma during plasma processing to define a predetermined gap. N spacers are disposed at N spaced apart locations on at least one of a radially inner surface and a radially outer surface of the annular body to reduce variations in the predetermined gap as the upper ring and the lower ring are heated and cooled during plasma processing, where N is an integer between 3 and 7 inclusive.

[0078] In other features, at least one of the N spacers includes a shim located in a slot on at least one of the radially inner and radially outer surfaces of the annular body. The shim has a rectangular cross-section. The slot is located on the radially outer surface of the first annular body. At least one of the N spacers includes a pin located in a slot on at least one of the radially inner and radially outer surfaces of the first annular body. The slot is located on the radially outer surface of the first annular body.

[0079] In other features, the N spacers are spaced apart at 360° / N intervals. At least one of the N spacers includes a protrusion formed on at least one of the radially inner and radially outer surfaces of the first annular body. The protrusion is located on the radially outer surface of the inner ring. A coating covers the protrusion. The coating includes an insulating material. The coating is selected from the group consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA), aluminum oxide deposited using atomic layer deposition, yttrium oxide deposited using atomic layer deposition, and yttrium fluoride deposited using atomic layer deposition. In other features, N=5.

[0080] Other areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief description of the drawings]

[0081] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0082] [Figure 1A] FIG. 1A is a functional block diagram of an example substrate processing system according to the present disclosure.

[0083] [Figure 1B] FIG. 1B is a cross-sectional view of an example of a movable edge ring according to the present disclosure. [Figure 1C] FIG. 1C is a cross-sectional view of an example of a movable edge ring according to the present disclosure.

[0084] [Diagram 2] FIG. 2 is a functional block diagram of another example of a substrate processing system according to the present disclosure.

[0085] [Figure 3A] FIG. 3A is a cross-sectional side view of an example of a movable edge ring according to the present disclosure.

[0086] [Figure 3B] FIG. 3B is an electrical schematic that models the movable edge ring of FIG. 3A.

[0087] [Figure 4] FIG. 4 is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0088] [Figure 5A] FIG. 5A illustrates the movement of different surfaces of a movable edge ring relative to adjacent structures. [Figure 5B] FIG. 5B illustrates the movement of different surfaces of the movable edge ring relative to adjacent structures.

[0089] [Figure 6A] FIG. 6A is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 6B] FIG. 6B is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 6C] FIG. 6C is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 6D] FIG. 6D is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0090] [Figure 7A] FIG. 7A is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 7B] FIG. 7B is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0091] [Figure 8A] FIG. 8A is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 8B] FIG. 8B is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 8C]FIG. 8C is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0092] [Figure 9A] FIG. 9A is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 9B] FIG. 9B is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 9C] FIG. 9C is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0093] [Figure 9C1] FIG. 9C1 is a partial bottom view of a partial upper edge ring according to the present disclosure.

[0094] [Figure 9C2] FIG. 9C2 is a cross-sectional view of a portion of a top edge ring according to the present disclosure.

[0095] [Figure 9D] FIG. 9D is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 9E] FIG. 9E is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 9F] FIG. 9F is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 9G] FIG. 9G is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0096] [Figure 10A] FIG. 10A is a cross-sectional side view of another example of a movable edge ring including embedded conductors according to the present disclosure. [Figure 10B] FIG. 10B is a cross-sectional side view of another example of a movable edge ring including embedded conductors according to the present disclosure.

[0097] [Figure 11A]FIG. 11A is a cross-sectional side view of another example of a movable edge ring including embedded conductors according to the present disclosure. [Figure 11B] FIG. 11B is a cross-sectional side view of another example of a movable edge ring including embedded conductors according to the present disclosure.

[0098] [Figure 11C] FIG. 11C is a cross-sectional view of an example of a movable edge ring and buried conductor according to the present disclosure. [Figure 11D] FIG. 11D is a cross-sectional view of an example of a movable edge ring and buried conductor according to the present disclosure. [Figure 11E] FIG. 11E is a cross-sectional view of an example of a movable edge ring and buried conductor according to the present disclosure.

[0099] [Figure 12A] FIG. 12A is a cross-sectional side view of another example of a movable edge ring including embedded conductors according to the present disclosure. [Figure 12B] FIG. 12B is a cross-sectional side view of another example of a movable edge ring including embedded conductors according to the present disclosure.

[0100] [Figure 13A] FIG. 13A is a cross-sectional side view of another example of a movable edge ring including a doped conductive portion in accordance with the present disclosure. [Figure 13B] FIG. 13B is a cross-sectional side view of another example of a movable edge ring including a doped conductive portion in accordance with the present disclosure.

[0101] [Figure 14A] FIG. 14A is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 14B] FIG. 14B is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 14C] FIG. 14C is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0102] [Figure 15]FIG. 15 is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0103] [Figure 16A] FIG. 16A is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 16B] FIG. 16B is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 16C] FIG. 16C is a cross-sectional side view of another example of a movable edge ring according to the present disclosure. [Figure 16D] FIG. 16D is a cross-sectional side view of another example of a movable edge ring according to the present disclosure.

[0104] [Figure 17] FIG. 17 is a cross-sectional view of a portion of upper and lower edge rings in accordance with the present disclosure.

[0105] [Figure 18] FIG. 18 is a graph showing the increase in capacitance as a function of percent shift from the nominal gap in accordance with the present disclosure.

[0106] [Figure 19] FIG. 19 is a side cross-sectional view of an edge ring system including an upper ring and a lower ring in accordance with the present disclosure.

[0107] [Figure 20] FIG. 20 is a side cross-sectional view of an edge ring system including upper and lower rings including multiple shims in accordance with the present disclosure.

[0108] [Figure 21] FIG. 21 is a side cross-sectional view of an edge ring system including upper and lower rings including a plurality of pins in accordance with the present disclosure.

[0109] [Figure 22A] FIG. 22A is a side cross-sectional view of an edge ring system including upper and lower rings including multiple protrusions in accordance with the present disclosure.

[0110] [Figure 22B] FIG. 22B is an enlarged cross-sectional side view of a lower edge ring including a protrusion with a raised flat portion in accordance with the present disclosure.

[0111] In the drawings, reference numbers may be reused to refer to similar and / or identical elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0112] During substrate processing, the substrate is placed on a pedestal, such as an electrostatic chuck (ESC), process gases are supplied, and a plasma is struck within the processing chamber, where exposed surfaces of components within the processing chamber are subject to abrasion by the plasma.

[0113] For example, an edge ring is placed around the radially outer edge of the substrate to shape the plasma. After processing the substrate, the exposed surface of the edge ring wears away and is at a different height relative to the substrate. As a result, the effect of the edge ring on the plasma changes, which in turn changes the effect of the process on the substrate. To reduce process changes due to edge ring wear without breaking vacuum, some processing chambers increase the height of the edge ring to compensate for the wear. In many of these systems, the edge ring height is automatically adjusted based on the number of cycles and / or the total plasma processing exposure duration. Other systems measure the edge ring height and adjust the height based on the measured height.

[0114] When the edge ring height is adjusted, the capacitive coupling between the plasma, the sheath, and / or the capacitive delivery structure (including the edge ring) changes. These changes in capacitive coupling can cause non-uniformities in substrate processing over time. Various edge ring configurations according to the present disclosure significantly reduce changes in the capacitance of the delivery structure due to changes in edge ring height.

[0115] More specifically, a plasma sheath is formed between the plasma and the feed components. In some examples, an RF bias is output to the substrate support. To maintain control of the sheath at low RF bias frequencies (e.g., less than 5 MHz or less than 1 MHz) to ensure process uniformity, it is necessary to maintain the capacitance value of the feed components to the substrate support as the edge ring height is adjusted to compensate for wear. Regions of the edge ring and / or nearby structures that capacitively couple are designed to minimize changes in capacitive coupling as the top edge ring moves. In some examples, capacitance is minimized in regions that move away as the edge ring height increases. Capacitance is controlled in other surface regions that do not change (or change less) as the edge ring height increases.

[0116] In some examples, the edge ring is made of a conductive material. As used herein, a conductive material is defined as a material that is 4 It refers to materials that have a resistivity of Ωcm or less. For example, doped silicon has a resistivity of 0.05 Ωcm, silicon carbide has a resistivity of 1 to 300 Ωcm, and metals such as aluminum or copper have a resistivity of about 10 -7 In another example, the edge ring may be made of a non-conductive or dielectric material (resistivity ≥ 10 4 In another example, the edge ring is made of a dielectric material and includes doped regions that are more conductive than the undoped regions. The doped regions are designed to minimize changes in capacitive coupling as the edge ring moves to offset wear.

[0117] 1A and 2, an example of a plasma processing chamber using a movable edge ring is shown. As can be appreciated, other types of plasma processing chambers may be used. In FIG. 1A, an example of a substrate processing system 110 according to the present disclosure is shown. The substrate processing system 110 may be used to perform etching using a capacitively coupled plasma (CCP). The substrate processing system 110 includes a processing chamber 122 that surrounds other components of the substrate processing system 110 and contains an RF plasma (if used). The substrate processing system 110 includes an upper electrode 124 and a substrate support 126, such as an electrostatic chuck (ESC). During operation, a substrate 128 is disposed on the substrate support 126.

[0118] By way of example only, the upper electrode 124 may include a gas distribution device 129, such as a showerhead, for introducing and distributing process gases. The gas distribution device 129 may include a stem portion including one end connected to the upper surface of the processing chamber. The annular body is generally cylindrical and extends radially outward from the opposite end of the stem portion at a location spaced from the upper surface of the processing chamber. The substrate-facing surface or faceplate of the showerhead annular body includes a plurality of holes through which precursors, reactants, etching gases, inert gases, carrier gases, other process gases, or purge gases flow. Alternatively, the upper electrode 124 may include a conductive plate, and the process gases may be introduced in another manner.

[0119] The substrate support 126 includes a base plate 130 that acts as a lower electrode. The base plate 130 supports a heating plate 132, which may correspond to a ceramic multi-zone heating plate. A coupling and / or thermal resistance layer 134 may be disposed between the heating plate 132 and the base plate 130. The base plate 130 may include one or more channels 136 for flowing a coolant through the base plate 130.

[0120] The RF generation system 140 generates and outputs an RF voltage to one of the upper electrode 124 and the lower electrode (e.g., the base plate 130 of the substrate support 126). The other of the upper electrode 124 and the base plate 130 can be DC grounded, AC grounded, or floating. By way of example only, the RF generation system 140 may include an RF generator 142 that generates RF plasma power that is supplied to the upper electrode 124 or the base plate 130 by a match and distribution network 144. In other examples, the plasma may be generated inductively or remotely.

[0121] Gas delivery system 150 includes one or more gas sources 152-1, 152-2, ..., and 152-N (collectively gas sources 152), where N is an integer greater than zero. Gas sources 152 are connected to manifold 160 by valves 154-1, 154-2, ..., and 154-N (collectively valves 154) and MFCs 156-1, 156-2, ..., and 156-N (collectively MFCs 156). Secondary valves may be used between MFCs 156 and manifold 160. Although a single gas delivery system 150 is shown, more than one gas delivery system may be used.

[0122] The temperature controller 163 may be connected to a plurality of thermal control elements (TCEs) 164 disposed on the heating plate 132. The temperature controller 163 may be used to control the plurality of TCEs 164 to control the temperature of the substrate support 126 and the substrate 128. The temperature controller 163 may be in communication with a coolant assembly 166 to control the flow of coolant through the channels 136. For example, the coolant assembly 166 may include a coolant pump, a reservoir, and / or one or more temperature sensors. The temperature controller 163 operates the coolant assembly 166 to selectively flow coolant through the channels 136 to cool the substrate support 126.

[0123] The valve 170 and the pump 172 can be used to discharge the reactant from the processing chamber 122. The system controller 180 can be used to control the components of the substrate processing system 110. The edge ring 182 can be disposed radially outside the substrate 128 during plasma processing. The edge ring height adjustment system 184 can be used to adjust the height of the upper surface of the edge ring 182 relative to the substrate 128, as further described below. In some examples, the edge ring 182 can also be raised, removed by the robot end effector, and replaced with another edge ring without breaking the vacuum.

[0124] Referring now to FIGS. 1B and 1C, in some examples, the substrate 128 is placed on the upper surface 190 of the substrate support 126 (or ESC). In FIG. 1B, the edge ring 182 is placed on the intermediate edge ring 186 and the bottom edge ring 188. The intermediate edge ring 186 and the bottom edge ring 188 are not moved. The edge ring 182 defines a height h above the upper surface 190 when the edge ring 182 is placed on the intermediate edge ring 186 and the bottom edge ring 188 and the edge ring 182 is not worn. One or more openings 192 are defined in one or more of the substrate support 126, the intermediate edge ring 186, and / or the bottom edge ring 188, enabling the height adjuster to adjust the height of the edge ring 182, as further described below.

[0125] In FIG. 1C, the edge ring 182 is worn and its thickness has decreased to a height h' (h' < h). The height adjuster is used to raise the edge ring 182 and restore the height relationship h between the upper surface of the edge ring 182 and the upper surface 190. When the edge ring 182 is worn sufficiently, the edge ring 182 can be replaced with a new edge ring.

[0126] In FIG. 2, an example of a substrate processing system 210 according to the present disclosure is shown. The substrate processing system 210 performs etching using an inductively coupled plasma. The substrate processing system 210 includes a coil driver circuit 211. A pulse circuit 214 can be used to pulse the RF power on and off or to vary the amplitude or level of the RF power. A conditioning circuit 213 can be directly connected to one or more inductive coils 216. The conditioning circuit 213 adjusts the output of the RF source 212 to a desired frequency and / or a desired phase, matches the impedance of the coils 216, and splits the power between the coils 216. In some examples, the coil driver circuit 211 is replaced by one of the driver circuits described further below in connection with controlling the RF bias.

[0127] In some examples, a plenum 220 may be disposed between the coil 216 and the dielectric window 224 to control the temperature of the dielectric window 224 with hot and / or cold airflow. The dielectric window 224 is disposed along one side of the processing chamber 228. The processing chamber 228 further comprises a substrate support (or pedestal) 232. The substrate support 232 may include an electrostatic chuck (ESC), or a mechanical chuck or other type of chuck. Process gases are supplied to the processing chamber 228, and a plasma 240 is generated inside the processing chamber 228. The plasma 240 etches the exposed surface of the substrate 234. A drive circuit 252 (such as one described below) may be used to provide an RF bias to an electrode in the substrate support 232 during operation.

[0128] A gas delivery system 256 can be used to supply a process gas mixture to the processing chamber 228. The gas delivery system 256 can include process and inert gas sources 257, a gas metering system 258, such as valves and mass flow controllers, and a manifold 259. A gas delivery system 260 can be used to deliver gas 262 to the plenum 220 via valve 261. The gas can include a cooling gas (air) used to cool the coil 216 and the dielectric window 224. A heater / cooler 264 can be used to heat / cool the substrate support 232 to a predetermined temperature. An exhaust system 265 includes valves 266 and pumps 267 that remove reactants from the processing chamber 228 by purging or evacuation.

[0129] A controller 254 can be used to control the etching process. The controller 254 monitors system parameters and controls the delivery of gas mixtures, striking, maintaining, and extinguishing the plasma, removing reactants, supplying cooling gases, and the like. In addition, as described in more detail below, the controller 254 can control various aspects of the coil driver circuit 211 and the driver circuit 252. An edge ring 282 can be positioned radially outward of the substrate 234 during plasma processing. A height adjustment system 284 can be used to adjust the height of the top surface of the edge ring 282. In addition, the edge ring 282 can be optionally removed when worn and replaced with a new edge ring without breaking vacuum. The controller 254 can be used to control the height adjustment system 284.

[0130] During processing, a plasma is struck in the processing chamber. In some examples, an RF bias is output to the substrate support. To maintain control of the plasma sheath at the low bias frequency, the capacitance C of the delivery components (such as the top, middle, and bottom edge rings) to the substrate support is adjusted as the height of the top edge ring adjusts due to wear. Dmust be maintained. In the examples below, the edge ring is made of a conductive or dielectric material and has embedded electrodes. As explained further below, the regions providing capacitive coupling are designed to minimize changes in capacitive coupling as the top edge ring moves.

[0131] 3A, an edge ring system for a substrate support includes a top edge ring 310, a middle edge ring 314, and a bottom edge ring 316. The top edge ring 310 has an inverted "U" shape and includes an annular body 330 connected to a radially inner leg 332 and a radially outer leg 334. The middle edge ring 314 has a "U" shape and includes an annular body 340 connected to a radially inner leg 342 and a radially outer leg 344. The radially inner leg 332 of the top edge ring 310 is located between the radially inner leg 342 and the radially outer leg 344 of the middle edge ring 314.

[0132] The bottom edge ring 316 includes a radially outer portion 350, a middle portion 352, and a radially inner portion 354. An annular recessed portion 360 is disposed on an upper and radially inner surface of the bottom edge ring 316 between the radially outer portion 350 and the middle portion 352. An annular recessed portion 364 is disposed on an upper and radially inner surface of the bottom edge ring 316 between the radially inner portion 354 and the middle portion 352. The bottom edge ring 316 includes an elongated vertical bore 374 configured to receive a lift pin 372 used to raise or lower the top edge ring 310. Similarly, the base plate 130 may include an elongated vertical bore 376 configured to receive the lift pin 372 and aligned with the elongated vertical bore 370. Although a single lift pin is shown, N lift pins may be used, where N is an integer greater than 2. In some examples, the N lift pins are spaced apart by an angle equal to 360° / N.

[0133] During operation, a plasma 380 is generated. A sheath 390 is formed between the plasma 380 and a delivery component 392 (including the top edge ring 310, the middle edge ring 314, and / or the bottom edge ring 316).

[0134] 3B, an electrical model of the plasma, sheath, and feed components 392 is shown. The sheath 390 has a sheath capacitance C S and the feeding component 392 has a feeding capacitance C D If the capacitance of the feed component 392 changes in response to component wear or adjustment of the edge ring height, the process may become non-uniform, resulting in performance variations and / or defects.

[0135] Referring now to FIG. 4, various parameters can be adjusted to vary the capacitance of the feed components. In FIG. 4, the top edge ring 420 has an inverted "U" shape and includes a radially inner leg 422 connected to a radially outer leg 426 by an annular body 424. The middle edge ring 430 has a "U" shape and includes a radially outer leg 432 connected to a radially inner leg 438 by an annular body 436. The radially inner leg 422 of the top edge ring 420 is disposed between the radially inner leg 438 and the radially outer leg 432 of the middle edge ring 430. The electrostatic electrode 410 and the RF electrode 412 of the base plate 130 are also shown.

[0136] The bottom edge ring 440 includes a middle portion 444, an upper portion 446 that projects upwardly from the middle portion 444 adjacent the radially outer edge of the bottom edge ring 440, and a lower portion 448 that projects downwardly from the middle portion 444 adjacent the radially outer edge of the bottom edge ring 440. The bottom edge ring 440 includes a radially inner portion 450 with an upper protrusion 452 on its upper radially inner surface. The base plate 130 includes a stepped portion 456 that receives the radially inner portion 450 of the bottom edge ring 440. Cavities 462 and 464 in the bottom edge ring 440 and base plate 130, respectively, mutually receive lift pins 470.

[0137] In some examples, the top edge ring 420 and the middle edge ring 430 are made of a conductive material and the bottom edge ring 440 is made of a non-conductive material, such as a dielectric. In some examples, the lift pins 470 are made of a conductive or non-conductive material, such as a dielectric.

[0138] 5A and 5B, the coupling capacitance between two conductive surfaces decreases significantly as the gap between the opposing surfaces increases. When the edge ring is raised, the opposing surfaces in region A generally move away from each other with the same gap D. A In contrast, the gap D between the opposing surfaces of region B B increases proportionally as the edge ring moves up. The coupling capacitance of the opposing conductive surfaces is affected by both areas A and B. The coupling capacitance of area A remains stable as the edge ring moves, and the coupling capacitance of area B decreases as the edge ring moves.

[0139] According to the present disclosure, the binding capacity of region A is maximized since it is relatively constant, and the binding capacity of region B is minimized since it is varying. In some examples, the gap D for region A is A is set to its minimum value, and the gap D for region B is B is k*D Awhere k is a number equal to or greater than 2. In some examples, k is equal to 3. In some examples, the gap is set to a gap of 0.006 inches (0.1524 mm) or 6 mils (0.1524 mm) or less for areas where bonding is desired, and a gap of 0.012 inches (0.3048 mm) or 12 mils (0.3048 mm) or more for areas where bonding is not desired. In some examples, the gap is set to a gap of 0.006 inches (0.006 mm) or 6 mils (0.1524 mm) or less for areas where bonding is desired, and a gap of 0.018 inches (0.4572 mm) or 18 mils (0.4572 mm) or more for areas where bonding is not desired.

[0140] In Figures 5A and 5B, the facing surfaces of the edge ring body are shown moving. In region A, the facing surfaces of the edge ring have a gap D between them. A In region B, the opposing surfaces of the edge rings slide apart, creating a gap D between them. B increases.

[0141] In some cases, the gap D A is the minimum gap between the opposing surfaces of region A (d min ) is set based on the minimum gap d min is determined based on the tolerances and / or thermal expansion of the feed components over a given process temperature range. A is the minimum gap d in region A where the capacitance must be constant min In other areas where the capacitance is minimized (as the gap between the opposing surfaces increases), the gap D B is k*d min or greater (where k is a number equal to or greater than 2). In another example, k is equal to or greater than 3. As a result, the capacitance due to region A dominates the feeding capacitance, and the capacitance due to region B has a significantly reduced effect on the feeding capacitance.

[0142] 6A and 6B, edge ring 610 has a "U" shape and includes an inner leg 612 connected to an outer leg 616 by an annular body 614. A concave portion 618 is located between inner leg 612 and outer leg 616. Top edge ring 620 has an inverted "U" shape and includes an inner leg 622 connected to outer leg 626 by an annular body 624.

[0143] The edge ring 630 includes a radially inwardly projecting upper portion 632 connected by an intermediate portion 634 to a radially outwardly projecting portion 636. In some examples, the edge ring 630 has a "Z" shaped cross section. A protruding surface 638 extends radially inward from a mid-region of the intermediate portion 634 downward (towards a facing surface 639 of the edge ring 640) to a lower edge of the edge ring 630.

[0144] The edge ring 640 is located radially inward from the edge ring 630 and below the upper portion 632 of the edge ring 630. The edge ring 640 includes a body 642 having a generally rectangular cross-section, an upper portion 644, a lower portion 646, and a protruding portion 648 that projects downwardly from a lower radially inner surface of the edge ring 640. The outer edge ring 650 includes a body 652, a radially inward protruding portion 654 that projects radially inward adjacent an upper surface of the body 652, and a downward protruding portion 656 that projects downwardly from a radially outer surface of the outer edge ring 650. Annular recesses 658 and 659 provide clearance for the radially outward protruding portion 636 and the base plate 130, respectively.

[0145] An annular seal 660 is disposed in an annular slot 661 defined between the base plate 130, the heating layer 132, and the edge ring 640 to protect the coupling and / or thermal resistance layer 134 disposed between the heating layer 132 and the base plate 130. The lift pins 662 pass through guide sleeves 664 that are disposed in vertical bores 666 in the base plate 130.

[0146] The upper edge ring 620 rests on the edge ring 630. The inner leg 622 of the upper edge ring 620 is located between the inner leg 612 of the edge ring 610 and the radially inwardly protruding upper portion 632 of the edge ring 630. The edge ring 610 rests on the stepped surface of the heating layer 132. The edge ring 640 is radially outward of the heating layer 132 and the edge ring 610. The body 652 of the outer edge ring 650 is radially outward of the edge ring 630. The inwardly protruding portion 654 of the outer edge ring 650 is disposed between the outer leg 626 of the upper edge ring 620 and the radially outwardly protruding portion 636 of the edge ring 630. A vertical gap 690 is defined between the edge ring 630 and the edge ring 610. A horizontal gap 691 is defined between the upper portions of the edge rings 630 and 640. A vertical gap is defined between the edge ring 630 and the outer edge ring 650 .

[0147] 6B, as the upper edge ring 620 wears, the lift pins 662 move upward to urge the edge ring 630 upward to compensate for wear to the upper edge ring 620 due to exposure to the plasma and / or other process gas mixtures. As can be seen, the protruding portion 638 closes the gap D of the edge ring 640. A Similarly, the top surface of the edge ring 630 is disposed within a gap D of the bottom surface of the annular body. A The edge rings 630 and 640 are positioned within a gap between the lower portions of the edge rings 630 and 640. A minimum gap between the lower portions of the edge rings 630 and 640 is maintained for consistent capacitive coupling. The other gaps that are increased start out larger (more than twice the minimum gap) and are increased to reduce their effect on capacitive coupling. The gaps that are decreased start out larger than twice the minimum gap and remain at that size to reduce their effect on capacitive coupling.

[0148] 6C, an exemplary variation of the edge ring 630 is shown. The upper portion 632 of the edge ring 630' extends downward adjacent to the upper surface of the outer leg 616 of the edge ring 610 and adjacent to the upper surface of the upper portion 644 of the edge ring 640. The inner surface 637 of the edge ring 630 extends parallel to (and within a predetermined fixed distance of) the radially outer surface 641 of the edge ring 630. In some examples, the base height (e.g., from the upper surface of the upper edge ring to the upper surface of the heating layer 132) ranges from 1 mm to 6 mm. In some examples, the base height is 4 mm. In some examples, the gap between the bottom surfaces of the upper portions 632 of the edge ring 630' ranges from 0.1 mm to 1 mm. In some examples, the gap between the bottom surfaces of the upper portions 632 of the edge ring 630' ranges from 0.1 mm to 0.5 mm. As the gap increases, the coupling between them decreases, and vice versa.

[0149] In some examples, upper edge ring 620 is made of quartz, edge ring 630' is made of silicon or silicon carbide, edge ring 610 is made of quartz, and edge ring 640 is made of silicon or silicon carbide, although other materials can be used.

[0150] 6D, another variation of an edge ring 630'' and an upper edge ring 620' is shown. The upper portion 632 of the edge ring 630' extends radially inwardly less than the edge rings 630 and 630' shown above. The inner leg 622 of the upper edge ring 620' is radially wider (and extends radially outwardly further).

[0151] In some examples, upper edge ring 620 is made of quartz, edge ring 630'' is made of silicon or silicon carbide, edge ring 610 is made of quartz, and edge ring 640 is made of silicon or silicon carbide, although other materials can be used.

[0152] 7A and 7B, top edge ring 710 has a rectangular cross-section. Middle edge ring 720 is "L" shaped and includes a vertical leg 722 connected to a radially outwardly projecting leg 726. Bottom edge ring 740 includes an annular body 744, an upwardly projecting portion 742, a downwardly projecting portion 749, and an inwardly projecting portion 745.

[0153] A vertical bore 746 passes through the inwardly projecting portion 745 to allow lift pins 754 to pass one another to move the top edge ring 710. The inwardly projecting portion 745 includes an upwardly projecting portion 747 located adjacent the pins 754 and defines an annular recess that receives the outwardly projecting legs 726. The inwardly projecting portion 745 also includes a downwardly projecting portion 748 located near the radially inner surface of the bottom edge ring 740. The guide sleeve 750 sits in the annular recess defined by the downwardly projecting portion 748.

[0154] In some examples, the top edge ring 710 and the lift pins 754 are made of a conductive material. The middle edge ring 720 and the bottom edge ring 740 are non-conductive and made of a dielectric material. Capacitive coupling is maintained through the lift pins 754, which are conductive and in contact with the top edge ring 710 when the top edge ring 710 is raised in FIG. 7B.

[0155] 8A and 8B, the top edge ring 810 has an inverted "U" shape and includes an annular body 812 connected to an inner leg 814 and an outer leg 816. The outer edge ring 820 includes a middle portion 822, a lower portion 824, and an upper portion 828. The middle portion 822 projects radially inward below the upper portion 828 to form an annular recess 826 or step to receive the outer leg 816 of the top edge ring 810 when the top edge ring 810 is lowered. The lower portion 824 projects radially inward toward the base plate 130 to form a step 829.

[0156] The edge ring 840 is located below the upper edge ring 810 between the outer edge ring 820 and the base plate 130. The edge ring 840 includes a middle portion 842, an upper portion 843, and a lower portion 844. The edge ring 840 extends radially inwardly forming an annular recess 846 or step between the middle portion 842 and the upper portion 843. The edge ring 840 extends radially inwardly forming an annular recess 848 or step between the middle portion 842 and the lower portion 844. The edge ring 840 fills the gap D between the facing surfaces of the base plate 130. A The other surface of edge ring 840 (as shown in FIG. 8B ) that faces base plate 130 and changes in response to movement, is the gap D between the opposing surface of base plate 130 and the other surface of edge ring 840 (as shown in FIG. 8B ). B Located together with.

[0157] Edge ring 850 includes a body portion 852 having a generally rectangular cross-section. An annular recess or step 854 is located in an upper and radially outer portion of body portion 852. The inner legs of upper edge ring 810 reside in annular recesses 846 and 854.

[0158] In some examples, the top edge ring 810 is made of a conductive or dielectric material, the edge ring 850 and the outer edge ring 820 are made of a dielectric material, and the edge ring 840 is made of a conductive material. Although the lift pins 870 are shown passing through vertical bores in the edge ring 820, the base plate 130 can extend radially outward further and the lift pins can pass through the base plate 130 instead of the edge ring 820. In some examples, the radially inward facing surfaces of the lower portion 844 and the middle portion 842 are parallel to the radially outward facing surface of the base plate 130.

[0159] A first surface area of ​​a lower portion 844 of edge ring 840 that is adjacent to (and facing) base plate 130 remains the same as upper edge ring 810, as edge ring 840 is raised and lowered. A second surface area of ​​a middle portion 842 of edge ring 840 that is located further away from base plate 130 decreases as the edge ring is raised (because edge ring 850 is located between them).

[0160] 8C , edge ring 870 has a generally rectangular cross-section, an upper portion 872, and a lower portion 874. An annular seal 876 is disposed about the upper surface of base plate 130, radially outward of coupling and / or thermal resistance layer 134 below heater plate 132. Edge ring 880 has an "L" shaped cross-section and is located between edge ring 870 and heater plate 132. An annular recess 882 or step is disposed on an upper radially inner surface of edge ring 880.

[0161] Upper edge ring 884 has an inverted "U" shape, an annular body 885, a radially inner leg 886, and a radially outer leg 888. Outer edge ring 892 has a generally rectangular cross-section and is disposed radially outward of edge rings 870 and 884. Outer edge ring 892 has a generally rectangular cross-section, a radially inner and upper annular recess 894 or step that receives radially outer leg 888, and a radially inner and lower annular recess 896 or step that receives a lower radially outer portion of base plate 130.

[0162] 9A and 9B, the upper edge ring 910 has an inverted "U" shape and includes an annular body 912, an inner leg 914, and an outer leg 916. In some examples, the outer leg 916 is radially P times thicker than the inner leg 914, where P is greater than or equal to 2 and less than or equal to 5. The edge ring 920 is generally "L" shaped and includes an upwardly facing leg 922 and a radially inwardly facing leg 924. The edge ring 930 is generally "L" shaped and includes an upwardly facing leg 932 and a radially outwardly facing leg 934 having a radially outer portion that resides adjacent to the radially inner portion of the radially inner leg 924 of the edge ring 920.

[0163] The bottom edge ring 940 includes a middle portion 942. An upwardly facing portion 944 extends from a radially outer upper surface of the bottom edge ring 940. A downwardly facing portion 948 extends from a radially outer lower surface of the bottom edge ring 940. A radially inner portion 946 of the bottom edge ring extends radially inward beneath the outer leg 916 of the top edge ring 910 and a portion of the edge ring 920. An upwardly facing protrusion 949 extends upward a predetermined distance from the radially inner surface of the radially inner portion 946.

[0164] In some examples, the edge ring 920 and the top edge ring 910 are made of a conductive material, hi some examples, the edge rings 930 and 940 are made of a dielectric material.

[0165] The outer legs 916 of the upper edge ring 910 extend a predetermined distance less than the lowermost surface of the edge ring 920 when the upper edge ring is fully lowered, so that the facing surfaces of the upper edge ring 910 and edge ring 920 remain relatively the same as when the upper edge ring 910 is raised. In some examples, the predetermined distance is equal to or greater than the maximum increase in height of the upper edge ring 910 due to wear.

[0166] 9C, the upper edge ring 950 has an inverted "U" shape and includes an annular body 954, a radially inner leg 952, and a radially outer leg 956. In some examples, the radially outer leg 956 is radially P times thicker than the radially inner leg 952. The upper edge ring 950 includes a radial recess 957 located on a downwardly facing surface of the radially outer leg 956. An additional radial recess 957 is provided on each of the lift pins. In some examples, three lift pins are disposed around the edge ring and spaced at 120° intervals. The radial recess 957 includes an angled lower surface 958 that slopes downward and radially outward at an acute angle. The radial recess 957 and the angled lower surface 958 are biased by the lift pins and help to center the upper edge ring 950 relative to the base plate 130 and the substrate 128.

[0167] Additional views of the radial recess are shown in Figures 9C1 and 9C2. In Figure 9C1, a bottom view of a portion of the edge ring is shown. In Figure 9C2, a cross-sectional view along 9C2-9C2 of Figure 9C1 is shown. In some examples, surfaces 990 and 992 have a radius. In some examples, angle Θ is in the range of 75° to 105° (e.g., 90°).

[0168] The edge ring 960 is generally “U” shaped and includes an annular body 966, a radially inner leg 962, and a radially outer leg 964. The radially inner leg 952 of the upper edge ring 950 is located between the radially inner leg 962 and the radially outer leg 964 of the edge ring 960.

[0169] The edge ring 970 includes an annular recess 974 located on its radially inner and upper surfaces. The radially inner portion 972 of the edge ring 970 is disposed adjacent the base plate 130 and the heater plate 132. The lift pins pass through vertical bores in the radially inner portion 972 of the edge ring 970. The radially inner portion 972 of the edge ring 970 includes an annular recess 973 on its radially inner and upper surfaces to provide clearance and / or support for the lower portion of the radially outer leg 964 of the edge ring 960. The radially inner portion 972 of the edge ring 970 further includes a protrusion 975 extending downwardly from its lower and radially inner surfaces.

[0170] In some examples, the base plate 130 includes a compliant seal 971 that follows a stepped or lower radially outer surface of the base plate 130. In some examples, the compliant seal 971 is made of a material such as ceramic to reduce arcing. The lower surface of the edge ring 970 includes a first annular recess 976 or step that accommodates the lift pins and a second annular recess 978 that accommodates the base plate 130.

[0171] In some examples, the base height is 3.5 mm. In some examples, the edge rings 950 and 980 are made of a conductive material such as silicon or silicon carbide, although other materials can be used. In other examples, the edge rings 970 and 986 are made of quartz, although other materials can be used.

[0172] 9D, an example of a variation of the edge ring system of FIG. 9C is shown. An edge ring 980 is located below the upper edge ring 950. The edge ring 980 is generally "L" shaped and includes a radially inwardly protruding leg 984 and a vertical leg 982. The vertical leg 982 is located between the radially inner leg 952 and the radially outer leg 956 of the upper edge ring 950. The edge ring 986 is located below the substrate 128 and radially outward of the heater plate 132. The edge ring 986 is generally rectangular in shape with an annular recess 988 or step located on its underside and outer surface to receive the radially inwardly protruding leg 984.

[0173] In some examples, the base height (e.g., from the top surface of the upper edge ring 950 to the top surface of the base plate 130) is 3.5 mm. In some examples, the edge rings 950, 980, 986, and 970 are made of quartz, silicon carbide, silicon (or silicon carbide), and quartz, respectively, although other materials can be used.

[0174] Now referring to FIG. 9E, another exemplary variation of the edge ring system is shown. In FIG. 9E, the radially outer leg 956 of the upper edge ring 950' does not extend radially outward as much and is covered by the edge ring 990. The edge ring 990 has an "L" shaped cross section and includes a radially inward protruding leg 992 and a downward protruding leg 994 connected to the radially outer portion of the radially inward protruding leg 992. In some examples, the upper edge ring 950 of FIG. 9D may be too large to fit through the substrate port into the processing chamber. Splitting the upper edge ring 950 into two parts, as shown at 950' and 990 of FIG. 9E, allows the edge ring 990 to be removed and replaced through the substrate port (without breaking the vacuum if a vacuum transfer module is used). In some circumstances, the edge ring 950 of FIG. 9D may be too thick and / or heavy to be moved by a robotic arm. Using a thinner and lighter upper edge ring 990 in combination with edge ring 950'' allows edge ring 990 to be removed when worn because edge ring 990 is thinner and lighter.

[0175] In some examples, the base height (e.g., from the top surface of the upper edge ring 950 to the top surface of the base plate 130) is 3.5 mm. In some examples, the edge rings 990, 950, and 980 are made of silicon carbide, the edge ring 986 is made of silicon, and the edge ring 970 is made of quartz, although other materials can be used.

[0176] 9F, an edge ring 950″ similar to the top edge ring 950 of FIG. 9C with tighter tolerances is shown. In some examples, the gap between the edge rings is greater than 0.01 mm and is equal to or less than 0.5 mm, 0.25 mm, 0.2 mm, or 0.1 mm. In other examples, the gap between the top edge ring and the substrate is greater than 100 μm and is less than 500 μm, 400 μm, or 350 μm. In some examples, the base height (e.g., from the top surface of the top edge ring 950′ to the top surface of the base plate 130) is 5.5 mm. In some examples, the edge rings 950′, 980, and 970 are made of quartz, although other materials can be used.

[0177] 9G, the outer edge ring 995 defines an annular recess 974 or step on its upper surface and a protrusion 996 extending radially inward from the outer edge ring 995 adjacent the annular recess 974. The edge ring 997 has a generally rectangular cross-section and includes an annular recess 998 or step located on its radially outer and upper surface for receiving the protrusion 996. The edge ring 997 includes a protrusion 999 extending upwardly from an upper radially inner surface of the edge ring 997 adjacent the radially outer surface of the heating plate 132. In some examples, the edge ring 950'' is made of silicon (or quartz, or silicon carbide), the edge ring 980 is made of silicon or silicon carbide, the edge ring 997 is made of ceramic, aluminum, or quartz, and the edge ring 970 is made of quartz, although other materials may be used. Protrusions 996 on edge ring 970 and annular recesses 998 on edge ring 997 define a serpentine path to reduce plasma arcing.

[0178] 10A and 10B, instead of relying on the capacitance of a conductive edge ring, the edge ring can be made of a dielectric material and can include embedded conductors with no external connectors. For example, in FIG. 10A and 10B, the edge ring 920 of FIG. 9A and 9B can be made of a dielectric material and can include embedded conductors 1008 that are made of a metal. The top edge ring 910 is made of a conductive material.

[0179] The embedded conductor 1008 includes a vertical conductive portion 1010 and a horizontal conductive portion 1020. The embedded conductor 1008 is positioned to provide a relatively constant capacitance when the top edge ring 910 is raised due to wear, as shown in FIG. 10B. In the example of FIGS. 10A and 10B, the horizontal conductive portion 1020 provides coupling to the heater plate 132. As the top edge ring 910 moves upward due to wear, the horizontal conductive portion 1020 maintains coupling to the heater plate 132. As a result, the capacitance of the feed component remains approximately the same.

[0180] 11A and 11B, the edge ring 840 is made of a dielectric material (instead of a conductive material as in FIGS. 8A and 8B above) and includes embedded conductors 1108 with no external connections. The top edge ring 810 is made of a conductive or dielectric material. The embedded conductors 1108 include upper horizontal conductors 1110 that are disposed parallel to and near the lower surface of the top edge ring 810. The upper horizontal conductors 1110 are connected to vertical conductors 1112 that extend near the middle of the middle edge ring 840. The vertical conductors 1112 connect to horizontal conductors 1120 that extend radially inward and connect to vertical conductors 1122. The vertical conductors 1122 are disposed near and extend along the radially inner surface of the edge ring 840 near the lower portion.

[0181] In FIG. 11B, as edge ring 840 rises to compensate for wear on top edge ring 810, the coupling between vertical conductors 1110 and top edge ring 810 remains relatively constant (and DA Similarly, the coupling between the vertical conductors 1122 and the conductive opposing surfaces of the base plate 130 remains relatively constant (and D A Elsewhere, the buried conductor is D B The gap distance is equal to or greater than 1 mm.

[0182] 11C-11E, an arcuate portion of an edge ring 840 is shown. The edge ring 840 can be made of multiple ceramic green sheets that are stacked and sintered. Prior to sintering, vertical conductors or vias are formed by drilling holes in adjacent ceramic green sheets and filling the holes with a conductive material, such as a conductive paste. In some examples, tungsten paste is used. Horizontal conductors are formed by printing traces or conductive planes on the ceramic green sheets using a conductive material. In some examples, the horizontal conductors are printed to overlap and contact the vertical conductors and provide a connection between them.

[0183] In Figure 11C, vertical conductors 1112 or vias are shown connected to a conductive plane 1150 that defines horizontal conductors 1110. In Figure 11D, where there are no horizontal conductors, the vertical conductors pass through the ceramic green sheets. In Figure 11E, instead of using a conductive plane as shown in Figure 11D, multiple traces 1160 can be used to implement the horizontal conductors 1110 in place of the conductive plane 1150.

[0184] 12A and 12B, the top edge ring 710 of FIG. 7 can be made of a dielectric material instead of a conductive material. The top edge ring 710 includes a buried conductor 1208 with no external connection. The buried conductor 1208 includes a horizontal conductor 1210 that is disposed parallel to the top surface of the top edge ring 710. The horizontal conductor 1210 is spaced a predetermined distance from the top surface to allow for abrasion of the dielectric material without exposing the horizontal conductor 1210. A vertical conductor 1220 extends vertically near the middle portion of the top edge ring 710. The vertical conductor 1220 connects to the horizontal conductor 1210 and to a horizontal conductor 1224 that is disposed parallel to the bottom surface of the top edge ring 710. The horizontal conductor 1224 allows for capacitive coupling to the lift pin 754. The lift pin 754 is made of a conductive material. As can be seen in FIG. 11B, the coupling between the lift pins 754 and the horizontal conductors 1224 remains constant even as the upper edge ring 710 is lifted.

[0185] 13A and 13B, edge ring 840 is made of a dielectric or conductive material (as defined herein) and includes one or more doped regions that are more conductive than the remaining undoped regions. Top edge ring 810 is made of a conductive or dielectric material.

[0186] In this example, the top surface 1320 of the edge ring 840 underlying the upper edge ring 810 is doped to a predetermined depth to make the material more conductive than undoped material. Similarly, the radially inner surface 1322 of the edge ring 840 is also doped to a predetermined depth to make the dielectric material more conductive from the top surface 1320 to the bottom edge of the lower surface 849. The top surface 1320 and the radially inner surface 1322 are electrically connected. Although a single continuous doped region is shown, two or more doped regions may be used.

[0187] For example, edge ring 840 can be made of silicon carbide doped with boron, aluminum, or nitrogen to make selected portions of it more conductive than undoped regions. In FIG. 13B, the conductive portions of edge ring 840 provide uniform bonding to adjacent surfaces as the middle edge ring rises due to wear of top edge ring 810.

[0188] 14A, an upper edge ring 1410 is disposed over edge rings 1412, 1416, and 1420. The upper edge ring 1410 has an inverted "U" shape and includes an annular body 1434, a radially inner leg 1432, and a radially outer leg 1436. The annular body 1434 has a thickness t that allows for enough material to stabilize the edge ring during handling and enough material to allow for a sufficient number of cycles before replacement due to erosion. In some examples, the thickness t ranges from 0.5 mm to 10 mm, although other thicknesses can be used. In some examples, the thickness t ranges from 0.5 mm to 5 mm, although other thicknesses can be used.

[0189] The top surface 1438 of the radially outer leg 1436 slopes linearly downward (to form a sloped surface) at 1438'' relative to the radially outer edge of the top edge ring 1410 near the middle portion of the top edge ring 1410. The sloped portion 1438' slopes linearly downward a vertical distance d from the top surface 1438'. A horizontal distance h is provided from the radially outer edge of the "U" shape to where the top surface 1438 begins to slope downward. In some examples, depending on the thickness t, the horizontal distance h ranges from 0 mm to 10 mm, although other horizontal distances can be used. In some examples, d is equal to or greater than t. In some examples, d ranges from t to 3t. In some examples, d is equal to or less than t. In some examples, d ranges from 0.25*t to t. The edge rings 1412 and 1416 have an "L" shaped cross section.

[0190] In some examples, the top surface 1438 has a total thickness H. In some examples, the total edge ring thickness H ranges from 5 mm to 20 mm. In some examples, the distance d is 5%, 10%, 20%, 30%, 40%, or 50% or more of the height H. In some examples, the angled portion 1438' is linearly sloped at an acute angle. In some examples, the angled portion 1438' is sloped at an acute angle ranging from 20° to 70°.

[0191] The edge ring 1410 is generally taller than previous edge rings to allow for longer wear and accommodate the "U" shape. If there is not enough material between the "U" shape and the top surfaces 1438 and 1438', wear can cause the edge ring to crack. As can be appreciated, removing material in the radially outer sloped portion reduces the weight of the edge ring 1410, thereby reducing the load on the actuator. This allows the actuator to make finer adjustments. The linear slope of the sloped portion 1438' increases the amount of material that can be removed without removing too much material between the "U" groove and the top surfaces 1438 and 1438', as compared to a stepped design. In some examples, the distance d is greater than the thickness t of the annular body 1434 to increase the amount of material removed. In some examples, the horizontal distance h is less than the thickness t of the annular body 1434 to increase the amount of material removed.

[0192] The edge ring 1412 is located radially outward of the edge ring 1416 and below the upper edge ring 1410. The edge ring 1412 includes an upwardly protruding leg 1448 and a leg 1446 extending radially inward from the upwardly protruding leg 1448. The edge ring 1416 is located radially inward of the edge ring 1412 and below the substrate 128, adjacent the heater plate 132. The edge ring 1416 includes an upwardly protruding leg 1440 and a leg 1442 extending radially outward from the upwardly protruding leg 1440.

[0193] The edge ring 1420 includes a radially outer portion 1452 and a radially inner portion 1454 extending radially inward from a lower portion of the radially outer portion 1452. A step surface 1455 supports the radially outer leg 1436 of the upper edge ring 1410 when lowered. An upper protrusion 1456 extends upward from an inner upper surface of the radially inner portion 1454. Lift pins 1460 travel reciprocally within vertical bores in the radially inner portion 1454 of the edge ring 1420 to raise and lower the edge ring 1410.

[0194] 14B, the upper edge ring 1410 includes an alternative upper surface profile. A sloped portion 1464' of the upper surface of the edge ring 1410 slopes downward in a radially outward direction. The sloped portion 1464' transitions to a surface 1466, which is generally parallel to a plane that contains the substrate 128. Removing edge ring material at the sloped portion 1464' reduces the weight of the upper edge ring 1410. The reduced weight allows for use with lift actuators with reduced lifting capacity.

[0195] 14C, the radially inner edge 1470 of the upper edge ring 1410 defines a gap relative to the radially outer surface of the upwardly protruding leg 1440 of the edge ring 1416. The gap is increased as compared to the edge ring system of FIGS. 14A and 14B.

[0196] 15, the edge ring system includes an upper edge ring 1510, an outer edge ring 1520, and an edge ring 1530. The edge ring 1530 is located below the upper edge ring 1510 and radially inward of the outer edge ring 1520. The upper edge ring 1510 includes a generally rectangular body 1514 and radially inwardly protruding legs 1516 extending from a radially inner and upper surface of the upper edge ring 1510. The edge ring 1530 is generally rectangular and includes an annular recess 1534 located on its upper and radially inner surface. The substrate 128 is received in the annular recess 1534. The outer edge ring 1520 includes a radially outer portion 1522 and an inner portion 1524 extending radially inward from a middle portion of the radially outer portion 1522. The lift pins 1560 travel reciprocally within vertical bores in the interior portion 1524 of the outer edge ring 1520. A protrusion 1526 extends upwardly from a radially inner and upper surface of the outer edge ring 1520. The generally rectangular body 1514 of the upper edge ring 1510 is received on an upper surface 1555 of the outer edge ring 1520 between the protrusion 1526 and the radially outer portion 1522.

[0197] In some examples, the top surface 1518 of the edge ring 1510 has a height H before the angled portion 1518'. The angled portion 1518' slopes downward a distance d from the top surface 1518 to the radially outer edge of the top edge ring 1510. In some examples, the distance d is 5%, 10%, 20%, 30%, 40%, or 50% or more of the height H. In some examples, the angled portion 1518' slopes downward at an acute angle. In some examples, the angled portion 1518' slopes at an acute angle in the range of 20° to 70°. As can be appreciated, the material removed to form the angled portion 1518' helps reduce the weight of the edge ring 1510, which reduces the load on the actuator and improves reliability.

[0198] In some examples, the heating plate 132 has a cylindrical center portion 1577 and a protruding portion 1579 that extends radially outward from a bottom portion of the cylindrical center portion. In some examples, the heating plate 132 does not include an RF electrode. In other examples, the RF electrode located on the heating plate 132 near the edge ring is eliminated. For example, the RF electrode is eliminated in a region 1580 of the heating plate that is located below the edge ring 1530.

[0199] 16A-16C, a movable edge ring system 1600 is shown. In FIG. 16A, the movable edge ring system 1600 includes an upper edge ring 1610 that includes an annular body 1612. A radially outer leg of the upper edge ring 1610 projects downwardly from a radially outer surface of the annular body 1612. A radially inner leg 1616 projects downwardly from a radially inner surface of the annular body 1612. An inwardly projecting leg 1618 extends radially inwardly from a lower end of the radially inner leg 1616. The inwardly projecting leg 1618 extends below a radially outer edge of the substrate 128. In some examples, the heating layer 132 includes an annular recess 1619, and the inwardly projecting leg 1618 is received in the annular recess 1619 on its upper surface between the substrate 128 and the annular recess 1619.

[0200] The edge ring 1620 includes an annular body 1622. Radially outwardly projecting legs 1624 extend from an upper and radially outer surface of the annular body 1622. Radially inwardly projecting legs 1528 extend radially inward from a radially inner and lower surface of the annular body 1622. The edge ring 1620 is located radially outward of the upper edge ring 1610.

[0201] The edge ring 1630 is located radially inward of the edge ring 1620 and below the upper edge ring 1610. The edge ring 1630 includes an annular body 1632. Radially inwardly protruding legs 1634 extend radially inward from an upper and radially inner surface of the annular body 1632. As described further below in connection with Figures 17-22, the edge ring 1632 may include spacers 1633, such as shims, pins, or protrusions, to maintain spacing between the edge ring 1630 and the edge rings 1620 and / or 1640. As described further below, insulating coatings may be used.

[0202] The edge ring 1640 is located below the edge ring 1620 and radially outward of a lower portion of the edge ring 1630. The edge ring 1640 includes an annular body 1642 with radially downwardly projecting legs 1644 extending from a radially outer and lower surface of the annular body 1642. An inwardly projecting leg 1646 extends radially inward from a middle and inner portion of the annular body 1642. The inwardly projecting leg 1646 includes a vertical bore 1647 that receives a lift pin 1648. The edge ring 1640 includes annular recesses 1650 and protrusions 1652 that define a vertical bore in a lower surface of the edge ring 1640 for receiving a guide sleeve 1660 that is disposed in a vertical bore 1664 in the base plate 126. The edge ring 1640 includes an annular recess 1654 on its lower and radially inner surfaces to provide clearance for the radially outer edge of the base plate 126 .

[0203] When biased by the lift pins 1648 against the lower surface of the edge ring 1610, the edge ring 1630 defines a first vertical gap 1670 between the radially inner leg 1634 and the upper surface of the heating layer 132. The edge ring 1630 also defines a second vertical gap 1672 between the lower surface of the edge ring 1630 and the upper surface of the radially inwardly protruding leg 1646.

[0204] 16B , when the lift pins 1648 are fully lowered, the edge ring 1630 defines a third vertical gap 1680 between a lower surface of the edge ring 1610 and an upper surface of the edge ring 1630. The lower surface of the edge ring 1630 rests on the upper surface of the radially inwardly protruding legs 1646. In operation, the edge ring 1630 can be placed in an abutting relationship with the edge ring 1610 by raising the lift pins 1648, or in a spaced relationship with the edge ring 1610 by lowering the lift pins 1648 and the edge ring 1630.

[0205] Once the edge ring 1610 wears away due to exposure to the plasma, the substrate 128 is removed and the lift pins 1648 lift the edge ring 1630 and edge ring 1610 upwards, as shown in FIG. 16C. The edge ring 1610 is removed from the processing chamber through the substrate port using a robot arm (such as a vacuum transfer module robot arm). Another edge ring 1610 is fed over the edge ring 1630 (through the substrate port using a robot arm) and the lift pins 1648 are lowered. In some examples, the top ring 1610 is made of either a conductive material or a dielectric material, the ring 1630 is made of either a conductive material or a dielectric material with an embedded electrode, and the rings 1620 and 1640 are made of a dielectric material.

[0206] 16D, the edge ring 1640 of FIGS. 16A-16C can be split into two concentric rings. The inner ring 1680 includes an annular body 1682 and an annular recess 1684 located on a lower and radially inner surface (similar to the annular recess 1650 of FIGS. 16A-16C). The inner ring 1680 is made of a conductive material to enhance capacitive coupling with the edge ring 1630. This arrangement allows more RF to be transmitted between the base plate 126 and the edge ring 1630.

[0207] The outer ring 1690 includes an annular body 1692 made of a dielectric material. The annular body 1692 is located radially outward of the inner ring 1680. A radially inner surface 1694 of the outer ring 1690 resides adjacent to the radially outer surface 1686 of the inner ring 1680.

[0208] 17 and 18, many of the examples discussed above include an upper ring that is exposed to the plasma and a lower ring that is located below and shielded from the direct plasma by the upper ring. For example, a cross section of a portion of an edge ring system 1700 designed to have capacitive coupling is shown in FIG. 17. The lower portion of the upper ring 1710 is located radially outward of the lower portion of the lower ring 1720.

[0209] To maintain control of the plasma sheath at low bias frequencies, the value of the coupling capacitance C must remain fixed and relatively constant as the upper ring 1710 is exposed to the plasma, undergoes erosion, and its height increases. Additionally, there may be significant temperature differences between the upper ring 1710 and the lower ring 1720. For example, during plasma processing, the temperature difference between the upper ring 1710 and the lower ring 1720 may range from 0° C. to 200° C. (e.g., 100° C.). In some instances, because the lower ring 1720 expands when heated and contracts when cooled, the lower ring 1720 (or the upper ring 1710) may move or advance in a direction parallel to the substrate toward one side of the upper ring 1710, effectively reducing some radial gaps and increasing other radial gaps.

[0210] Assuming C is the capacitance between the upper ring 1710 and the lower ring 1720, as the lower ring 1720 moves off-center (closer to the upper ring 1710 in some radial directions and further away from the upper ring 1710 in other radial directions), the capacitance increases since it is a non-linear function of the gap. More specifically, the capacitance C shifted =S(s')*C centeredwhere s'=d / (R2-R1), 0≦s'≦1, R2 is the inner diameter of the upper ring 1710, and R1 is the outer diameter of the lower ring 1720. In FIG. 18, the relative increase in capacitance is shown as a function of the % shift of the nominal gap. As can be seen, the capacitance is affected when the shift exceeds about 35-40% of the nominal gap.

[0211] Systems and methods according to the present disclosure use spacers, such as shims, pins, or protrusions on the upper or lower rings, to limit movement of the upper ring 1710 relative to the lower ring 1720 during heating and cooling experienced during plasma processing. In some examples, movement is limited to no more than 20%, 30%, or 40% of the nominal gap to limit the effect of relative movement on the capacitance of the edge ring system.

[0212] 19-22, various methods of limiting movement of an upper ring relative to a lower ring of an edge ring system are shown. In FIG. 19, an edge ring system 1900 includes an upper ring 1910 including inner and outer portions 1910-1 and 1910-2 located adjacent radially inner and outer surfaces, respectively, of a lower ring 1920. In FIG. 20-22, various methods of limiting movement of the upper ring 1910 relative to the lower ring 1920 are shown.

[0213] In FIG. 20 , the lower ring 1920 includes a slot 1938 located on its radially outer surface. The slot 1938 extends radially inward toward the radially outer surface of the lower ring 1920. A shim 1934 is disposed in the slot 1938. In some examples, an adhesive 1930 is used to hold the shim 1934 in the slot 1938. In some examples, the shim 1934 has a rectangular plan, radial and side cross section, although other shapes can be used. In some examples, the shim 1934 has a radial thickness that is equal to or greater than the depth of the slot 1938. In some examples, the shim 1934 extends radially outward from the lower ring 1920 a sufficient distance to limit movement (considering the number of shims used).

[0214] In FIG. 21 , the lower ring 1920 includes slots 1948 located on its radially outer surface. The slots 1948 extend radially inward. The pins 1950 are disposed in the slots 1948. In some examples, an adhesive 1930 is used to hold the pins 1950 in the slots 1948. In some examples, the pins 1950 have a cylindrical shape, although other shapes can be used. In some examples, the pins 1950 have a radial height that is equal to or greater than the depth of the slots 1948. In some examples, the pins 1950 extend radially from the lower ring 1920 a sufficient distance to limit movement (considering the number of pins used).

[0215] In FIGS. 22A and 22B, the lower ring 1920 includes protrusions 1960 formed on its radially outer surface. In some examples, the protrusions 1960 extend vertically partially or completely along the vertical thickness of the radially outer surface. In FIG. 22B, the protrusions 1960 include flat surfaces 1964 extending from the radially outer surface 1962 of the lower edge ring 1920, which are easier to machine and inspect for dimensions compared to an arcuate profile. In other words, in some examples, the edge ring is first formed slightly wider without the protrusions 1960, and then the radially outer surface is machined or removed in the areas between adjacent protrusions to form the protrusions 1960. In other examples, the protrusions 1960 include an arcuate or convex profile in plan view, reducing the surface area in contact with the radially inwardly facing surface of the upper edge ring, reducing friction when making height adjustments or replacing the upper edge ring without breaking vacuum.

[0216] In some examples, the protrusions 1960 are coated with a coating material 1964. In some examples, the coating material 1964 is relatively conformal and made of an insulating material. In some examples, the coating is selected from the group consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA), or aluminum oxide, yttrium oxide, or yttrium fluoride deposited using atomic layer deposition. The coating material 1964 has an insulating function to prevent short circuits and reduce erosion. The coating material 1964 also ensures a minimum gap between the lower ring 1920 and the upper ring 1910 to prevent short circuits. In some examples, the protrusions 1960 extend radially outward from the radially outer surface of the lower ring 1920 a sufficient distance to limit movement (considering the number of protrusions used).

[0217] In some examples, the lower ring 1920 includes between three and eight spacers (shims, one or more protrusions) that are uniformly spaced around the circumference of the lower ring 1920 (e.g., 120° intervals for three, 72° intervals for five, 45° intervals (or 360° / N) for eight). As can be appreciated, the spacers are generally not configured to completely limit relative movement of the upper and lower rings. The gaps help to reduce coupling during height adjustment and / or replacement. Thus, some relative movement is still desirable, and undesirable movement (which may change the effective coupling capacity) may still occur even with three shims. In some examples, the lower ring 1920 includes five spacers that are positioned around the circumference of the lower ring 1920 to further limit movement. Depending on the particular configuration, additional spacers such as six, seven, or eight provide diminishing returns with respect to control of the effective coupling capacity and increase costs.

[0218] Although spacers (e.g., shims, one or more protrusions) are shown disposed on the outer surface of the lower ring 1920, spacers may also be disposed on one or both of the inner surface of the lower ring 1920 and / or the inner surface of the upper ring 1910. Additionally, spacers and / or insulating coatings may be disposed on any of the aforementioned examples (e.g., FIGS. 1-22) on one or both of the radially facing surfaces of the edge ring intended to be capacitively coupled.

[0219] In some examples, the spacers extend in a radially outward direction between 50 μm and 250 μm from the radially outer surface of the edge ring. In some examples, the spacers extend in a radially outward direction between 50 μm and 250 μm from the radially outer surface of the edge ring.

[0220] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure can be embodied in various forms. Thus, while the disclosure includes specific examples, the true scope of the disclosure should not be limited to such examples, since other modifications will become apparent upon review of the drawings, the specification, and the following claims. It should be understood that one or more steps in a method may be performed in different orders (or simultaneously) without altering the principles of the disclosure. Furthermore, although each embodiment is described above as having certain features, any one or more of these features described with respect to any embodiment of the disclosure can be implemented in other embodiments and / or combined with any features of the other embodiments (even if such combination is not explicitly described). In other words, the described embodiments are not mutually exclusive, and it is within the scope of the disclosure to substitute one or more embodiments for one another.

[0221] Spatial and functional relationships between elements (e.g., modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Also, when a relationship between a first element and a second element is described in the above disclosure, unless expressly described as "direct," the relationship may be a direct relationship in which there are no other intervening elements between the first element and the second element, but may also be an indirect relationship in which there are one or more intervening elements (spatial or functional) between the first element and the second element. As used herein, the phrase at least one of A, B, and C should be interpreted in the sense of a logic (A or B or C) using a non-exclusive logical OR, and not in the sense of "at least one of A, at least one of B, and at least one of C."

[0222] In some implementations, the controller is part of a system, and such a system may be part of the examples described above. Such a system may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling system operations before, during, and after processing of a semiconductor wafer or substrate. Such electronics may be referred to as a "controller" and may control various components or subparts of one or more systems. The controller may be programmed to control any of the processes disclosed herein depending on the processing requirements and / or type of system. Such processes may include delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer loading and unloading from the tool, and wafer loading and unloading from other transport tools and / or load locks connected or interfaced with the particular system.

[0223] Broadly, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, i.e., microcontrollers, that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. The operational parameters may, in some embodiments, be part of a recipe defined by a process engineer to accomplish one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0224] The controller, in some embodiments, may be part of, coupled to, or a combination of a computer that is integrated or coupled with the system or otherwise networked to the system. For example, the controller may be in the "cloud" or all or part of a fab host computer system. This allows for remote access of wafer processing. The computer may allow remote access to the system to monitor the current progress of a fabrication operation, review the history of past fabrication operations, review trends or performance criteria from multiple fabrication operations, modify parameters of a current process, set processing steps following a current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system over a network. Such a network may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data. Such data identifies parameters for each processing step performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool that the controller is configured to interface with or control. Thus, as discussed above, the controller may be distributed, for example, by having one or more individual controllers networked together and working together toward a common purpose (such as the processes and controls described herein). An example of a distributed controller for such purposes would include one or more integrated circuits on the chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer) and coupled to control the process in the chamber.

[0225] Exemplary systems may include, but are not limited to, a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a tracking chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0226] As described above, depending on the process step or steps being performed by the tool, the controller may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used for material transport to and from tool locations and / or load ports within a semiconductor manufacturing factory.

Claims

1. 1. An edge ring for a plasma processing system, comprising: An annular body; a radially inner leg extending from the annular body; a radially outer leg extending from said annular body; Equipped with a first portion of an upper surface of the edge ring is parallel to a plane containing the substrate; the second portion of the upper surface slopes downwardly at an angle from the first portion; a third portion of the upper surface is parallel to the plane containing the substrate and is radially outward of the second portion of the upper surface. Edge ring.

2. 2. The edge ring of claim 1, an edge ring, the first portion of the upper surface being located radially inward of the second portion of the upper surface;

3. 2. The edge ring of claim 1, The edge ring has an inverted "U" shape.

4. 4. The edge ring of claim 3, an edge ring, wherein the second portion of the upper surface begins to slope downwardly from a radially outer edge of the inverted "U" at a horizontal distance h, the horizontal distance h being in the range of 0 mm to 10 mm.

5. 2. The edge ring of claim 1, An edge ring, wherein the thickness t of the annular body is in the range of 0.5 mm to 10 mm.

6. 6. The edge ring of claim 5, the second portion of the upper surface slopes downwardly a vertical distance d that is greater than or equal to 20% of the height of the total thickness of the edge ring.

7. 6. The edge ring of claim 5, the second portion of the upper surface slopes downwardly a vertical distance d, where d is greater than or equal to t.

8. 8. The edge ring of claim 7, d is in the range of t to 3t, edge ring.

9. 2. The edge ring of claim 1, A second portion of the upper surface is linearly tapered at an acute angle.

10. The edge ring of claim 1, the edge ring having an inverted "U" shape; the second portion of the upper surface begins to slope downwardly a horizontal distance h from the radially outer edge of the inverted "U" shape; An edge ring, wherein a horizontal distance between a tilt start position of the second portion and a tilt end position of the second portion is greater than the horizontal distance h.

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