Moveable edge rings with reduced capacitance variation for substrate processing systems

Abstract

The movable edge ring system for a plasma processing system includes a top edge ring and a first edge ring disposed below the top edge ring. A second edge ring, made of conductive material, includes an upper portion, a middle portion, and a lower portion. The top edge ring and the second edge ring are configured to move vertically relative to the substrate support and the first edge ring when tilted upwards by a lifting pin. The second edge ring is disposed below the top edge ring and radially outward of the first edge ring.

Description

Technical Field

[0001] The present invention generally relates to plasma processing systems, and more particularly to edge ring systems having a movable edge ring. [Cross-reference to related applications]

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 976,088, filed on February 13, 2020, and U.S. Provisional Patent Application No. 62 / 882,890, filed on August 5, 2019. The entire disclosures of the aforementioned applications are incorporated herein by reference. Prior Art

[0003] The background description provided herein is intended to outline the context of the present invention. The inventors' work (to the extent described in this prior art section), as well as aspects of the description that may not otherwise be identified as prior art at the time of filing, is not admitted, either explicitly or implicitly, as prior art to the present invention.

[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 a processing chamber to process the substrate. Plasma may be used to ignite the gas, enhancing chemical reactions.

[0005] During processing, a substrate is positioned on a substrate support. An edge ring is annular and positioned around and adjacent to the radially outer edge of the substrate. The edge ring can be used to shape or focus the plasma onto the substrate. During operation, the exposed surfaces of the substrate and edge ring are etched by the plasma. Consequently, the edge ring wears, and its effect on the plasma varies over time. Summary of the Invention

[0006] A movable edge ring system for a plasma processing system includes a top edge ring and a first edge ring disposed below the top edge ring. A second edge ring is made of a conductive material and includes an upper portion, a middle portion, and a lower portion. The top edge ring and the second edge ring are configured to move vertically relative to a substrate support and the first edge ring when biased upward by lift pins. The second edge ring is disposed below the top 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 middle portion to define a first gap between the lower portion of the second edge ring and the radially outer surface of the substrate support. The middle portion of the second edge ring defines a second gap between the middle portion and the radially outer surface of the substrate support. The second gap is greater than or equal to twice the first gap.

[0008] In other features, when the lift pins raise the second edge ring and the top edge ring, the middle portion of the second edge ring moves parallel to the radially outer edge 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 first edge ring is made of a conductive material. The first edge ring is made of a dielectric material. The middle portion of the second edge ring extends radially inward relative to the upper portion of the second edge ring to define a first annular recess.

[0009] In other features, the first edge ring includes a second annular recess on its upper and radially outer surface. When the top edge ring is in the lowered position, the radially inner leg of the top edge ring is located between the first annular recess and the second annular recess.

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

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

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

[0013] In other features, the second edge ring is disposed below the top 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 top 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 middle portion and defines a first gap between the lower portion of the first edge ring and the radially outer surface of the substrate support. The middle portion of the first edge ring defines a second gap between the middle portion and the radially outer surface of the substrate support. The second gap is greater than or equal to twice the first gap.

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

[0016] In other features, the embedded conductor includes a horizontal conductor disposed in the upper portion and parallel to the upper surface of the first edge ring. The embedded conductor further includes a vertical conductor disposed in the lower portion and parallel to the radially inner surface of the first edge ring. The embedded conductor further includes a conductor connecting the vertical conductor 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 third edge ring is positioned below and radially outward of the first edge ring, the second edge ring, and the top edge ring. The third edge ring defines an annular recess on its upper and radially inner surface. When the top edge ring is in the lowered position, the radially outer leg of the top edge ring is positioned in the annular recess. The third edge ring includes a vertical hole to receive the lift pin.

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

[0019] A movable edge ring system for a plasma processing system includes a top edge ring. The first edge ring is made of 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 positioned below the top edge ring. The top edge ring and the first edge ring are configured to move vertically relative to a substrate support when biased upward by lift pins.

[0020] In other features, the second edge ring is disposed below the top 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 top 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 middle portion and defines a first gap between the lower portion of the first edge ring and the radially outer surface of the substrate support. The middle portion of the first edge ring defines a second gap between the middle portion and the radially outer surface of the substrate support. The second gap is greater than or equal to twice the first gap.

[0022] In other features, when the lift pins raise the first edge ring and the top edge ring, the middle portion of the first edge ring moves parallel to the radially outer edge of the second edge ring. The doped region is disposed along the upper surface and 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, the third edge ring is positioned below and radially outward of the first edge ring, the second edge ring, and the top edge ring. The third edge ring defines an annular recess on its upper and radially inner surface. When the top edge ring is in the lowered position, the radially outer leg of the top edge ring is positioned in the annular recess. The third edge ring includes a vertical hole to receive a lift pin.

[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 portion protrudes radially inward from a radially inner surface of the annular body between the upper portion and the middle portion. A second step portion protrudes radially inward from a radially inner surface of the annular body between the middle portion and the lower portion.

[0025] In other features, the ring system is made of a dielectric material and further includes an embedded conductor disposed entirely within the ring body. The embedded conductor includes a horizontal conductor disposed in the upper portion and parallel to the upper outer surface of the ring body. The embedded conductor further includes a vertical conductor disposed in the lower portion and parallel to the radially inner surface of the ring body. The embedded conductor further includes a conductor connecting the vertical conductor and the horizontal conductor. The ring system is made of a dielectric material and further includes a doped region and an undoped region. The doped region of the ring body is more conductive than the undoped region. The doped region is disposed on the upper and radially inner surfaces of the ring body. The ring system is made of a ceramic green sheet containing conductive traces and through-holes.

[0026] An edge ring for a plasma processing system includes an annular body made of a dielectric material and configured to surround a substrate support of the plasma processing system. An embedded conductor is disposed entirely within the annular body and includes a first conductor disposed within the annular body and a second conductor disposed within the annular body, perpendicular to the first conductor, and connected to the first conductor.

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

[0028] In other features, the first conductor is arranged parallel to the first outer surface of the annular body. The third conductor is arranged parallel to the 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 protrudes radially inward therefrom. The second step is located on the radially inner surface of the annular body between the middle portion and the lower portion and protrudes radially inward therefrom.

[0029] In other features, a first conductor is arranged at the top parallel to a first outer surface of the ring body. A second conductor is arranged at the bottom parallel to a radially inner surface of the ring body. A third conductor connects the first conductor to the second conductor. The ring system is made of a ceramic green sheet including conductive traces and through-holes.

[0030] An edge ring for a plasma processing system includes an annular body configured to surround a substrate support of the plasma processing system. An embedded conductor is disposed within the annular body and configured to capacitively couple, but not directly couple, to at least one external conductive member 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 surround a substrate support. The annular body includes a doped region and an undoped region. The doped region is more conductive than the undoped region.

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

[0033] In other features, the dielectric material comprises silicon carbide. The dielectric material 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 a top edge ring. A first edge ring is disposed below the top 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 top edge ring and the second edge ring are configured to move vertically relative to the first edge ring and a substrate support when displaced 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 the predetermined gap of the radially outer surface of the first edge ring, and the remaining surface area of ​​the second edge ring is 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 middle portion extending in a vertical direction and connected to the upper portion; a lower portion connected to a lower end of the middle portion and projecting radially outward; and a protrusion extending radially inward from the middle portion and downwardly to a lower edge of the lower portion.

[0037] In other features, the mounting surface area is defined by a protrusion. The third edge ring is positioned below the top 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 positioned radially outward of the top edge ring and the second edge ring. The fourth edge ring includes a protrusion extending radially inward and disposed between the top edge ring and a portion of the second edge ring. The top edge ring has an inverted U-shape, a body, an inner leg, and an outer leg. In the lowered position, the top edge ring is adjacent to the second, third, and fourth edge rings.

[0038] In other features, the top edge ring is made of a conductive material, the top edge ring is made of a dielectric material, and 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 made of a conductive material and configured to surround a substrate support. Lift pins are also made of the conductive material. A lift pin actuator is configured to bias the lift pins against the first edge ring 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, the second edge ring is positioned radially inward and below the first edge ring. The second edge ring is made of a dielectric material. The second edge ring has an L-shaped cross-section and includes a radially inner leg extending vertically and a radially outer leg extending horizontally.

[0041] In other features, the third edge ring is located radially outward and below the first and second edge rings. 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 inward projection including a vertical hole to receive 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 an embedded conductor disposed entirely within the dielectric material, and configured to surround a substrate support. Lift pins are made of a conductive material. A lift pin actuator is configured to bias the lift pins against the first edge ring 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 embedded conductor includes a first horizontal conductor arranged parallel to a top surface of the first edge ring, a second horizontal conductor arranged 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, the second edge ring is located radially inward and below the first edge ring. The second edge ring is made of a dielectric material. The second edge ring has an L-shaped cross-section and includes a radially inner leg extending vertically and a radially outer leg extending horizontally.

[0046] In other features, the third edge ring is positioned radially outward and below the first and second edge rings. 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 inward projection including a vertical hole for receiving a lift pin.

[0047] A movable edge ring system for a plasma processing system includes a top edge ring having an inverted U-shaped cross-section and comprising an annular body, radially inner legs, and radially outer legs. A first edge ring is made of a conductive material and at least partially disposed between the radially inner and radially outer legs of the top edge ring. A second edge ring is made of a dielectric material and disposed between the first edge ring and a substrate support. A third edge ring is disposed below and radially outward of the first and second edge rings and includes N cavities for accommodating N lift pins, where N is an integer greater than 2. When displaced by the N lift pins, the top edge ring moves relative to the first, second, and third edge rings and the substrate support.

[0048] In other features, the second and third edge rings 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 top edge ring includes N radial recesses spaced 360° / N apart on the radially inner surface of the radially outer leg and includes a beveled lower surface extending radially outward from the radial recesses. When the height of the top edge ring is adjusted, the N lift pins offset the top edge ring within the N radial recesses.

[0049] An edge ring for a plasma processing system includes an annular body having an inverted U-shaped cross-section. A radially inner leg extends from the annular body. A radially outer leg extends from the annular body. N radial recesses spaced at 360⁰ / N intervals are located on the radial inner surface of the radially outer leg, where N is an integer greater than 2. The leg includes a beveled lower surface extending radially outward from the N radial recesses.

[0050] A 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 positioned between the radially inner and radially outer legs of the first edge ring. A second edge ring is disposed below and radially outward of the edge ring and the first edge ring and includes N vertical holes for accommodating N lift pins. When displaced by the N lift pins, the edge ring moves relative to the first and second edge rings and the substrate support.

[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 ring is configured to receive N lift pins in N radial recesses when adjusting the height of the edge ring.

[0052] A movable edge ring system includes edge rings. A 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 positioned between the radially inner leg and the radially outer leg of the edge ring. A second edge ring is positioned radially inward from the first edge ring. A third edge ring is positioned radially outward from the edge ring. The first and second edge rings include vertical holes for accommodating lift pins. When displaced by the lift pins, the edge rings move relative to the first, second, and third edge rings and the substrate support.

[0053] A movable edge ring system for a plasma processing system includes a top edge ring having an inverted U-shaped cross-section and comprising an annular body, radially inner legs, and radially outer legs. The first edge ring is made of a dielectric material and includes an embedded conductor disposed entirely within the dielectric material. The first edge ring is configured to surround a substrate support and at least partially disposed between the radially inner and radially outer legs of the top 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 and second edge rings and includes vertical holes for receiving lift pins. The top edge ring is movable relative to the first, second, and third edge rings when displaced by the lift pins.

[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 a ring body having a vertical leg connected to a horizontal leg. The embedded conductor includes a vertical conductor disposed in the vertical leg and a horizontal conductor disposed in the horizontal leg and connected to the vertical conductor.

[0055] An edge ring for a plasma processing system includes a ring body, a radially inner leg connected to the ring body, and a radially outer leg connected to the ring body. A first portion of a top surface of the ring body is parallel to a plane including a substrate. A second portion of the top surface of the ring body is inclined downward 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. The third portion of the upper surface is parallel to a plane including 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 is made of a conductive material and is configured to surround a substrate support and at least partially disposed 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 holes to accommodate lift pins. When deflected by the lift pins, the edge ring moves relative to the first and second edge rings and the substrate support.

[0059] An edge ring for a plasma processing system includes an annular body having a rectangular cross-section. A radially inwardly projecting leg extends from a radially inner and upper surface of the annular body. A radially inner portion of the upper surface of the annular body is arranged parallel to a plane including a substrate.

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

[0061] A movable edge ring system for a plasma processing system includes an edge ring. The middle edge ring is disposed below radially inwardly projecting legs and radially inward of the ring body. An outer edge ring is disposed below the edge ring and the middle edge ring and includes vertical holes for receiving lift pins. When deflected by the lift pins, the edge ring moves vertically relative to the middle and outer edge rings.

[0062] Among other features, the intermediate edge ring has a generally rectangular cross-section and an annular recess on its radially inner and upper surface. 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 the radially outer intermediate portion.

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

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

[0065] In other features, the plurality of RF electrodes are not located in a portion of the protrusion below the intermediate edge ring.

[0066] A movable edge ring system for a plasma processing system includes a top edge ring configured to surround a substrate support. The movable edge ring system includes an annular body; radially outer legs projecting downwardly from a radially outer surface of the annular body; radially inner legs projecting downwardly from a radially inner surface of the annular body; and inwardly projecting legs extending radially inwardly from lower ends of the radially inner legs. When a substrate is positioned on the substrate support, the inwardly projecting legs are positioned below the substrate. A first edge ring is configured to surround the substrate support and positioned below the top edge ring. The ring includes an annular body and radially inwardly projecting legs. When the first edge ring is deflected against the top edge ring, the upper surface of the first edge ring is positioned between the radially inner and radially outer legs of the top edge ring.

[0067] In other features, the second edge ring is disposed radially outward of the top edge ring and the first edge ring. The second edge ring includes an annular body; a radially outwardly projecting leg extending from an upper and radially outer surface of the annular body; and a radially inwardly projecting leg extending radially inwardly from a radially inner and lower surface of the annular body.

[0068] In other features, the inwardly projecting leg of the first edge ring extends radially inward from the 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 top 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 the 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 projecting leg of the third edge ring includes a vertical hole for receiving a lift pin. When biased against the top 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 a lower surface of the first edge ring and an upper surface of the inwardly projecting leg of the third edge ring.

[0070] In other features, when in the lowered position, the first edge ring abuts the inward leg of the third edge ring, and the protrusion defines a third vertical gap between an upper surface of the first edge ring and a lower surface of the top edge ring.

[0071] A plasma processing system includes a processing chamber. A substrate support is disposed within the processing chamber. The processing chamber includes a substrate port. A robotic arm transfers a substrate onto the substrate support. A movable edge ring system is disposed around the substrate support. Lift pins offset the top edge ring and the first edge ring relative to the substrate support.

[0072] In other features, the first edge ring and the top edge ring are raised relative to the substrate support via lift pins, the robot removes the top edge ring, and the robot transfers another top edge ring to the substrate support via the substrate port.

[0073] An edge ring system for a plasma processing system includes an upper ring comprising a first annular body configured to surround a substrate support during plasma processing. A lower ring comprises a second annular body configured to surround the substrate support during plasma processing. When configured for plasma processing, at least a portion of the second annular body of the lower ring nests relative to a portion of the first annular body of the upper ring, defining a predetermined gap. N spacers are disposed at N spaced locations on a surface of at least one of the upper and lower rings to reduce variations in the predetermined gap between the annular bodies of the upper and lower rings when the upper and lower rings are heated and cooled during plasma processing, where N is an integer greater than or equal to 3 and less than or equal to 8.

[0074] In other features, at least one of the N spacers comprises a washer positioned in a slot on a radially opposing surface of at least one of the upper and lower rings. The washer has a rectangular cross-section. The slot is located on the radially outer surface of the inner ring. At least one of the N spacers comprises a pin positioned 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 at intervals of 360° / N.

[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 the 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. Lift pins raise the upper ring relative to the lower ring to 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 relative to a portion of a second annular body of an upper ring exposed to the plasma during plasma processing and define a predetermined gap. N spacers are disposed at N spaced 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 when the upper and lower rings are heated and cooled during plasma processing, where N is an integer greater than or equal to 3 and less than or equal to 7.

[0078] In other features, at least one of the N spacers comprises a washer positioned in a slot on at least one of the radially inner and outer surfaces of the annular body. The washer 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 comprises a pin positioned in a slot on at least one of the radially inner and 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 arranged at intervals of 360° / N. At least one of the N spacers comprises a protrusion formed on at least one of the radially inner and 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 comprises an insulating material 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] Further areas of applicability of the present invention will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Simple diagram description

[0081] The present invention will be more fully understood through the detailed description and drawings, in which:

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

[0083] Figures 1B and 1C are cross-sectional views of examples of movable edge rings according to the present invention;

[0084] Figure 2 is a functional block diagram of another example of a substrate processing system according to the present invention;

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

[0086] Figure 3B is a schematic diagram of the movable edge ring modeling in Figure 3A;

[0087] Figure 4 is a sectional side view of another example of the movable edge ring according to the present invention;

[0088] Figures 5A and 5B are diagrams showing different surfaces of the movable edge ring moving relative to adjacent structures;

[0089] Figures 6A to 6D are cross-sectional side views of another example of a movable edge ring according to the present invention;

[0090] Figures 7A to 7B are cross-sectional side views of another example of a movable edge ring according to the present invention;

[0091] Figures 8A to 8C are sectional side views of another example of a movable edge ring according to the present invention;

[0092] Figures 9A to 9C are cross-sectional side views of another example of a movable edge ring according to the present invention;

[0093] Figure 9C1 is a partial bottom view of a portion of the top edge ring according to the present invention;

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

[0095] Figures 9D to 9G are cross-sectional side views of another example of a movable edge ring according to the present invention;

[0096] Figures 10A and 10B are cross-sectional side views of another example of a movable edge ring including an embedded conductor according to the present invention;

[0097] Figures 11A and 11B are cross-sectional side views of another example of a movable edge ring including an embedded conductor according to the present invention;

[0098] Figures 11C to 11E are cross-sectional views of examples of movable edge rings and embedded conductors according to the present invention;

[0099] Figures 12A and 12B are cross-sectional side views of another example of a movable edge ring including an embedded conductor according to the present invention;

[0100] Figures 13A and 13B are cross-sectional side views of another example of a movable edge ring including a doped conductive portion according to the present invention;

[0101] Figures 14A to 14C are sectional side views of another example of a movable edge ring according to the present invention;

[0102] Figure 15 is a sectional side view of another example of the movable edge ring according to the present invention;

[0103] Figures 16A to 16D are cross-sectional side views of other examples of the movable edge ring according to the present invention;

[0104] Figure 17 is a sectional view of a portion of the upper and lower edge rings according to the present invention;

[0105] Figure 18 is a graph showing the increase in capacitance as a function of the percentage of deviation from the nominal gap according to the present invention;

[0106] Figure 19 is a side sectional view of the edge ring system including an upper ring and a lower ring according to the present invention;

[0107] Figure 20 is a side sectional view of an edge ring system including an upper ring and a lower ring (which includes a plurality of gaskets) according to the present invention;

[0108] Figure 21 is a side sectional view of an edge ring system including an upper ring and a lower ring (which includes a plurality of pins) according to the present invention;

[0109] FIG22A is a side cross-sectional view of an edge ring system including an upper ring and a lower ring including a plurality of protrusions according to the present invention; and

[0110] 22B is an enlarged side cross-sectional view of a lower edge ring including a protrusion with a raised flat portion according to the present invention.

[0111] In the drawings, reference characters may be repeated to identify similar and / or identical elements. Implementation Method

[0112] During substrate processing, the substrate is placed on a pedestal, such as an electrostatic chuck (ESC), supplied with process gases, and subjected to plasma in a processing chamber. Exposed surfaces of components in the processing chamber are subject to wear and tear from the plasma.

[0113] For example, an edge ring is positioned around the radially outer edge of a substrate to shape the plasma. After processing a substrate, the exposed surface of the edge ring wears and is located at a different height relative to the substrate. As a result, the edge ring's effect on the plasma changes, which in turn alters the process's effect on the substrate. To reduce process variations caused by edge ring wear without breaking vacuum, some processing chambers raise the edge ring height to compensate for wear. In many of these systems, the edge ring height is automatically adjusted based on the number of cycles and / or the total plasma treatment exposure time. 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, sheath, and / or capacitive transfer structures (including the edge ring) changes. These variations in capacitive coupling can lead to non-uniformity in substrate processing over time. The various edge ring configurations according to the present invention significantly reduce capacitance variations in the transfer structures caused by variations in edge ring height.

[0115] More specifically, a plasma sheath is generated between the plasma and the transfer member. 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, the capacitance of the transfer member to the substrate support must be maintained while adjusting the edge ring height to compensate for wear. The edge ring and / or the capacitively coupled structures are designed to minimize changes in the capacitive coupling as the top edge ring moves. In some examples, capacitance is minimized in areas that move apart as the edge ring height increases. Capacitance is controlled in other surface areas 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 refers to a material with a resistivity less than or equal to 10⁻Ωcm. For example, doped silicon has a resistivity of 0.05 Ωcm, silicon carbide has a resistivity of 1-300 Ωcm, and metals (such as aluminum and copper) have a resistivity of ≈10⁻Ωcm. In other examples, the edge ring is made of a non-conductive or dielectric material (resistivity > 10⁻Ωcm) with an embedded conductive electrode. The embedded electrode is designed to minimize changes in capacitive coupling as the top edge ring moves. In other examples, the edge ring is made of a dielectric material and includes a doped region that is more conductive than the undoped region. The doped region is designed to minimize changes in capacitive coupling as the edge ring moves to offset wear.

[0117] Referring now to Figures 1A and 2 , an example plasma processing chamber using a movable edge ring is shown. It will be appreciated that other types of plasma processing chambers may be used. Figure 1A illustrates an example substrate processing system 110 according to the present invention. The substrate processing system 110 can be used to perform etching using capacitively coupled plasma (CCP). The substrate processing system 110 includes a processing chamber 122 that surrounds the other components of the substrate processing system 110 and contains the 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 positioned 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, that introduces and distributes process gases. The gas distribution device 129 may include a stem having one end connected to the top surface of the processing chamber. The annular body is generally cylindrical and extends radially outward from the opposite end of the stem at a location spaced from the top surface of the processing chamber. The substrate-facing surface or faceplate of the showerhead's annular body includes a plurality of apertures 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 by another means.

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

[0120] The RF generation system 140 generates an RF voltage and outputs it 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 can include an RF generator 142 that generates RF plasma power that is delivered to the upper electrode 124 or the base plate 130 by a matching and distribution network 144. In other examples, the plasma can 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 via valves 154-1, 154-2, ..., and 154-N (collectively, valves 154) and mass flow controllers (MFCs) 156-1, 156-2, ..., and 156-N (collectively, MFCs 156). Auxiliary valves may be used between MFCs 156 and manifold 160. Although a single gas delivery system 150 is shown, two or more gas delivery systems may be used.

[0122] The temperature controller 163 can be connected to a plurality of thermal control elements (TCEs) 164 disposed within the heating plate 132. The temperature controller 163 can 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 can be in communication with a coolant assembly 166 to control the flow of coolant through the channel 136. For example, the coolant assembly 166 can 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 channel 136 to cool the substrate support 126.

[0123] A valve 170 and a pump 172 can be used to exhaust reactants from the processing chamber 122. A system controller 180 can be used to control components of the substrate processing system 110. During plasma processing, an edge ring 182 can be positioned radially outward from the substrate 128. An edge ring height adjustment system 184 can be used to adjust the height of the top surface of the edge ring 182 relative to the substrate 128, as described further below. In some examples, the edge ring 182 can also be raised, removed by a robotic end effector, and replaced with another edge ring without breaking vacuum.

[0124] Referring now to FIGS. 1B and 1C, in some examples, the substrate 128 is located on the upper surface 190 of the substrate support 126 (or ESC). In FIG. 1B, the edge ring 182 is located on the intermediate edge ring 186 and the bottom edge ring 188. The intermediate edge ring 186 and the bottom edge ring 188 do not move. When the edge ring 182 is located on the intermediate edge ring 186 and the bottom edge ring 188 and the edge ring 182 is not worn, the edge ring 182 defines a height h above the upper surface 190. One or more openings 192 may be defined in one or more of the substrate support 126, the intermediate edge ring 186, and / or the bottom edge ring 188 to allow a height adjustment member to adjust the height of the edge ring 182, as will be further described below.

[0125] In FIG. 1C, the edge ring 182 is worn and the thickness is reduced to a height h' (h' < h). The height adjustment member is used to raise the edge ring 182 to restore the height relationship h between the top surface of the edge ring 182 and the upper surface 190. When the edge ring 182 is sufficiently worn, 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 invention is shown. The substrate processing system 210 uses inductively coupled plasma to perform etching. The substrate processing system 210 includes a coil drive circuit 211. The pulse circuit 214 can be used to pulse on and off the RF power or change the amplitude or level of the RF power. The tuning circuit 213 can be directly connected to one or more induction coils 216. The tuning circuit 213 tunes the output of the RF source 212 to a desired frequency and / or a desired phase, matches the impedance of the coil 216, and distributes the power between the coils 216. In some examples, in combination with controlling the RF bias, the coil drive circuit 211 is replaced with one of the drive circuits further described below.

[0127] In some examples, an air chamber 220 can be disposed between the coil 216 and the dielectric window 224 to control the temperature of the dielectric window 224 with a hot and / or cold air flow. The dielectric window 224 is disposed along one side of the processing chamber 228. The processing chamber 228 further includes a substrate support (or pedestal) 232. The substrate support 232 can include an electrostatic chuck (ESC), or a mechanical chuck, or other types of chucks. A process gas is 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 of the drivers described below) can be used to provide an RF bias to the electrodes 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 (e.g., 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 cooling gas (air) for cooling 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 a valve 266 and a pump 267 to remove reactants from the processing chamber 228 by purging or evacuating the chamber.

[0129] Controller 254 can be used to control the etching process. Controller 254 monitors system parameters and controls the delivery of the gas mixture, the impact, maintaining and extinguishing the plasma, the removal of reactants, the supply of cooling gases, and the like. Furthermore, as described in detail below, controller 254 can control various aspects of coil driver circuit 211 and driver circuit 252. During plasma processing, edge ring 282 can be positioned radially outward from substrate 234. A height adjustment system 284 can be used to adjust the height of the top surface of edge ring 282. Furthermore, edge ring 282 can be optionally removed and replaced with a new edge ring when worn without breaking vacuum. Controller 254 can be used to control 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 low bias frequencies, the capacitance CD of the transfer member (e.g., top, middle, and bottom edge rings) to the substrate support must be maintained as the height of the top edge ring adjusts due to wear. In the following examples, the edge ring is made of a conductive or dielectric material with embedded electrodes. As described further below, the region providing capacitive coupling is 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, an intermediate 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 intermediate 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 positioned between the radially inner leg 342 and the radially outer leg 344 of the intermediate 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 recess 360 is disposed on the upper radially inner surface of the bottom edge ring 316 between the radially outer portion 350 and the middle portion 352. An annular recess 364 is disposed on the upper 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 hole 374 configured to receive a lift pin 372 used to raise and lower the top edge ring 310. Similarly, the base plate 130 may include an elongated vertical hole 376 configured to receive the lift pin 372 and aligned with the elongated vertical hole 374. 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 at 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 transfer member 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 transfer member 392 is shown. The sheath 390 has a sheath capacitance CS, while the transfer member 392 has a transfer capacitance CD. If the capacitance of the transfer member 392 changes in response to member wear or adjustment of the edge ring height, the process will be less uniform and performance variations and / or defects may occur.

[0135] Referring now to FIG. 4 , various parameters can be adjusted to alter the capacitance of the transfer member. In FIG. 4 , top edge ring 420 has an inverted U-shape and includes radially inner leg 422 connected to radially outer leg 426 via annular body 424. Intermediate edge ring 430 has a U-shape and includes radially outer leg 432 connected to radially inner leg 438 via annular body 436. Radially inner leg 422 of top edge ring 420 is disposed between radially inner leg 438 and radially outer leg 432 of intermediate edge ring 430. Electrostatic electrode 410 and RF electrode 412 of base plate 130 are shown.

[0136] Bottom edge ring 440 includes a middle portion 444, an upper portion 446 (which projects upward from middle portion 444 and is adjacent to the radially outer edge of bottom edge ring 440), and a lower portion 448 (which projects downward from middle portion 444 and is adjacent to the radially outer edge of bottom edge ring 440). Bottom edge ring 440 includes a radially inner portion 450 having an upwardly projecting portion 452 on its upper radially inner surface. Bottom plate 130 includes a stepped portion 456 that receives radially inner portion 450 of bottom edge ring 440. Cavities 462 and 464 in bottom edge ring 440 and bottom plate 130, respectively, 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, while the bottom edge ring 440 is made of a non-conductive material (e.g., a dielectric material). In some examples, the lift pins 470 are made of a conductive or non-conductive material (e.g., a dielectric material).

[0138] Referring now to Figures 5A and 5B , as the gap between opposing surfaces increases, the coupling capacitance between two conductive surfaces decreases significantly. When the edge ring is raised, the gap DA between opposing surfaces in region A generally remains the same. Conversely, as the edge ring is raised, the gap DB between opposing surfaces in region B increases proportionally. The coupling capacitance between opposing conductive surfaces is affected by both regions A and B. Region A will maintain a stable coupling capacitance as the edge ring moves, while region B will experience a decreasing coupling capacitance as the edge ring moves.

[0139] According to the present invention, the coupling capacitance in region A is maximized due to its relative constancy, while the coupling capacitance in region B is minimized due to its variation. In some examples, the gap DA in region A is set to a minimum value, while the gap DB in region B is set to k*DA, where k is a number greater than or equal to 2. In some examples, k is equal to 3. In some examples, for regions where coupling is desired, the gap is set to a gap of less than or equal to 0.006" or 6 mils, while for regions where coupling is undesirable, the gap is set to a gap of greater than or equal to 0.012" or 12 mils. In some examples, for regions where coupling is desired, the gap is set to a gap of less than or equal to 0.006" or 6 mils, while for regions where coupling is undesirable, the gap is set to a gap of greater than or equal to 0.018" or 18 mils.

[0140] 5A and 5B illustrate the opposing surfaces of the edge ring during movement. In region A, the opposing surfaces of the edge ring slide adjacent to each other without significantly changing the gap DA therebetween. In region B, the opposing surfaces of the edge ring slide apart and increase the gap DB therebetween.

[0141] In some examples, gap DA is set based on the minimum gap (dmin) between opposing surfaces in region A. The minimum gap dmin is determined based on the tolerance and / or thermal expansion of the transfer component within a given process temperature range. Gap DA is set equal to the minimum gap dmin in region A where capacitance is to remain constant. In other regions where capacitance is to be minimized (due to increased gap between opposing surfaces), gap DB is set to be greater than or equal to k*dmin (where k is a number greater than or equal to 2). In other examples, k is greater than or equal to 3. As a result, the capacitance originating from region A dominates the transfer capacitance, while the capacitance originating from region B has a significantly reduced impact on the transfer capacitance.

[0142] 6A and 6B , edge ring 610 has a "U" shape and includes an inner leg 612 connected to an outer leg 616 via an annular body 614. A recessed 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 an outer leg 626 via an annular body 624.

[0143] Edge ring 630 includes a radially inwardly projecting upper portion 632 connected to a radially outwardly projecting portion 636 through a middle portion 634. In some examples, edge ring 630 has a "Z"-shaped cross-section. A projecting surface 638 extends radially inwardly and downwardly (toward an opposing surface 639 of edge ring 640) from a middle region of middle portion 634 to a lower edge of edge ring 630.

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

[0145] An annular seal 660 is disposed in an annular groove 661 defined between the base plate 130, the heating layer 132, and the edge ring 640 to protect the joint between the heating layer 132 and the base plate 130 and / or the thermal resistance layer 134. The lift pin 662 passes through a guide sleeve 664 disposed in a vertical hole 666 in the base plate 130.

[0146] Top edge ring 620 is positioned on edge ring 630. Inner leg 622 of top edge ring 620 is positioned between inner leg 612 of edge ring 610 and radially inwardly projecting upper portion 632 of edge ring 630. Edge ring 610 is positioned on the stepped surface of heating layer 132. Edge ring 640 is positioned radially outward of heating layer 132 and edge ring 610. Body 652 of outer edge ring 650 is positioned radially outward of edge ring 630. Inwardly projecting portion 654 of outer edge ring 650 is positioned between outer leg 626 of top edge ring 620 and radially outwardly projecting portion 636 of edge ring 630. A vertical gap 690 is defined between edge ring 630 and edge ring 610. A horizontal gap 691 is defined between upper portions of edge rings 630 and 640. A vertical gap is defined between edge ring 630 and outer edge ring 650.

[0147] In FIG6B , as top edge ring 620 wears, lift pins 662 move upward to bias edge ring 630 upward, compensating for wear of top edge ring 620 due to exposure to plasma and / or other process gas mixtures. It can be seen that protrusion 638 is disposed within gap DA of edge ring 640. Similarly, the top surface of edge ring 630 is disposed within gap DA of the bottom surface of the ring body. A minimum gap is maintained between the lower portions of edge rings 630 and 640 to achieve constant capacitive coupling. Other increased gaps start at a larger gap (≥ twice the minimum gap) and then increase to reduce the impact on capacitive coupling. Reduced gaps start at and remain greater than twice the minimum gap to reduce the impact on capacitive coupling.

[0148] Referring now to FIG. 6C , an exemplary variation of edge ring 630 is shown. The upper portion 632 of edge ring 630' extends downwardly adjacent to the upper surface of the outer leg 616 of edge ring 610 and adjacent to the upper surface of the upper portion 644 of edge ring 640. The inner surface 637 of edge ring 630 extends parallel to (and within a predetermined fixed distance from) the radially outer surface 641 of edge ring 640. In some examples, the base height (e.g., from the top surface of the top edge ring to the top 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 surface of the upper portion 632 of edge ring 630' and the upper surface of the outer leg 616 ranges from 0.1 mm to 1 mm. In some examples, the gap between the bottom surface of the upper portion 632 of edge ring 630' and the upper surface of the outer leg 616 ranges from 0.1 mm to 0.5 mm. Increasing the gap reduces coupling therebetween, and vice versa.

[0149] In some examples, top 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 may be used.

[0150] 6D , which illustrates another variation of edge ring 630 ″ and top edge ring 620 ′. The upper portion 632 of edge ring 630 ′ extends less radially inwardly than the aforementioned edge rings 630 and 630 ′. The inner leg 622 of top edge ring 620 ′ is wider in the radial direction (and extends further radially outward).

[0151] In some examples, top 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 may be used.

[0152] 7A and 7B , top edge ring 710 has a rectangular cross-section. Intermediate edge ring 720 is L-shaped and includes vertical legs 722 connected to radially outwardly projecting legs 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] Vertical holes 746 extend through inward projections 745 to allow lift pins 754 to pass through and move the top edge ring 710 accordingly. Inward projections 745 include upward projections 747 located adjacent to pins 754 to define an annular recess for receiving outwardly projecting legs 726. Inward projections 745 also include downward projections 748 located adjacent to the radially inner surface of bottom edge ring 740. Guide sleeve 750 is located in the annular recess defined by downward projections 748.

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

[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 protrudes radially inward below the upper portion 828 to form an annular recess 826 or step to accommodate the outer leg 816 of the top edge ring 810 when the top edge ring 810 is lowered. The lower portion 824 protrudes radially inward toward the base plate 130 to form a step 829.

[0156] Edge ring 840 is positioned below top edge ring 810 and between outer edge ring 820 and base plate 130. Edge ring 840 includes a middle portion 842, an upper portion 843, and a lower portion 844. Edge ring 840 extends radially inward to form an annular recess 846, or step, between middle portion 842 and upper portion 843. Edge ring 840 extends radially inward to form an annular recess 848, or step, between middle portion 842 and lower portion 844. Edge ring 840 includes a lower surface 849 positioned within gap DA between the opposing surface of base plate 130. Other surfaces of edge ring 840 that face base plate 130 and change with movement (as shown in FIG. 8B ) are positioned within gap DB between the opposing surface of base plate 130.

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

[0158] In some examples, top edge ring 810 is made of a conductive or dielectric material, edge ring 850 and outer edge ring 820 are made of a dielectric material, and edge ring 840 is made of a conductive material. Although lift pins 870 are shown extending through vertical holes in edge ring 820, base plate 130 may extend further radially outward, and the lift pins may extend through base plate 130 rather than edge ring 820. In some examples, the radially inward facing surfaces of lower portion 844 and intermediate portion 842 are parallel to the radially outward facing surfaces of base plate 130.

[0159] As top edge ring 810 and edge ring 840 are raised and lowered, the first surface area of ​​lower portion 844 of edge ring 840, which is adjacent to (and facing) base plate 130, remains the same. The second surface area of ​​middle portion 842 of edge ring 840, which is located further away from base plate 130, decreases as the edge ring is raised (because edge ring 850 is located therebetween).

[0160] Referring now to FIG8C , edge ring 870 has a generally rectangular cross-section, an upper portion 872, and a lower portion 874. An annular seal 876 is disposed around the upper surface of base plate 130 radially outwardly of the bonding and / or thermal resistance layer 134 below heater plate 132. Edge ring 880 has an "L"-shaped cross-section and is positioned between edge ring 870 and heater plate 132. An annular recess 882, or step, is disposed on the upper radially inner surface of edge ring 880.

[0161] Top 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 to accommodate radially outer leg 888, and a radially inner and lower annular recess 896 or step to accommodate the lower radially outer portion of base plate 130.

[0162] 9A and 9B , top 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, outer leg 916 is P times thicker in the radial direction than inner leg 914, where P is greater than or equal to 2 and less than or equal to 5. Edge ring 920 is generally "L"-shaped and includes an upward-pointing leg 922 and a radially inward-pointing leg 924. Edge ring 930 is generally "L"-shaped and includes an upward-pointing leg 932 and a radially outward-pointing leg 934, with the radially outer portion of radially outward-pointing leg 934 adjacent to the radially inner portion of radially inward-pointing leg 924 of edge ring 920.

[0163] Bottom edge ring 940 includes a middle portion 942. An upward-pointing portion 944 extends from the radially outer upper surface of bottom edge ring 940. A downward-pointing portion 948 extends from the radially outer lower surface of bottom edge ring 940. A radially inner portion 946 of the bottom edge ring extends radially inwardly below the outer leg 916 of top edge ring 910 and a portion of edge ring 920. An upward-pointing protrusion 949 extends upwardly from the radially inner surface of radially inner portion 946 a predetermined distance.

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

[0165] When the top edge ring is fully lowered, the outer legs 916 of the top edge ring 910 extend a predetermined distance below the lowermost surface of the edge ring 920. Thus, when the top edge ring 910 is raised, the opposing surfaces of the top edge ring 910 and the edge ring 920 remain relatively the same. In some examples, the predetermined distance is greater than or equal to the maximum height increase of the top edge ring 910 due to wear.

[0166] Referring now to FIG. 9C , top 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, radially outer leg 956 is P times thicker in the radial direction than radially inner leg 952. Top edge ring 950 includes radial recesses 957 located on downwardly facing surfaces of radially outer leg 956. Additional radial recesses 957 are provided for each lift pin. In some examples, three lift pins are arranged around the edge ring and spaced 120° apart. Radial recesses 957 include beveled lower surfaces 958 that slope downward and radially outward at an acute angle. Radial recesses 957 and beveled lower surfaces 958 are offset by the lift pins and help center top edge ring 950 relative to base plate 130 and base plate 128.

[0167] Figures 9C1 and 9C2 show additional views of the radial recess. Figure 9C1 shows a bottom view of a portion of the edge ring. Figure 9C2 shows a cross-sectional view taken along line 9C2-9C2 in Figure 9C1. In some examples, surfaces 959 and 961 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 top edge ring 950 is located between the radially inner leg 962 and the radially outer leg 964 of the edge ring 960.

[0169] Edge ring 970 includes an annular recess 974 on its radially inner and upper surface. Radially inner portion 972 of edge ring 970 is positioned adjacent to base plate 130 and heater plate 132. Lift pins extend through vertical holes in radially inner portion 972 of edge ring 970. Radially inner portion 972 of edge ring 970 includes an annular recess 973 on its radially inner and upper surface to provide clearance and / or support for the lower portion of radially outer leg 964 of edge ring 960. Radially inner portion 972 of edge ring 970 further includes a protrusion 975 extending downwardly from its lower and radially inner surface.

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

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

[0172] Referring now to FIG. 9D , an example variation of the edge ring system of FIG. 9C is shown. Edge ring 980 is positioned below top edge ring 950. Edge ring 980 is generally L-shaped and includes radially inwardly projecting legs 984 and vertical legs 982. Vertical legs 982 are positioned between radially inner legs 952 and radially outer legs 956 of top edge ring 950. Edge ring 986 is positioned below substrate 128 and radially outward of heater plate 132. Edge ring 986 is generally rectangular and has an annular recess 988 or step on its lower and outer surface to accommodate radially inwardly projecting legs 984.

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

[0174] Referring now to FIG. 9E , another exemplary variation of an edge ring system is shown. In FIG. 9E , radially outer legs 956 of top edge ring 950 ′ extend less radially outward and are covered by edge ring 990 . Edge ring 990 has an L-shaped cross-section and includes radially inwardly projecting legs 992 and downwardly projecting legs 994 connected to the radially outer portion of radially inwardly projecting legs 992 . In some cases, top edge ring 950 of FIG. 9D may be too large to fit through a substrate port into a processing chamber. Splitting top edge ring 950 into two parts, 950 ′ and 990 in FIG. 9E , allows edge ring 990 to be removed and replaced through the substrate port (without breaking vacuum when using a vacuum transfer module). In some cases, edge ring 950 of FIG. 9D may be too thick and / or too heavy to be moved by a robot. By using a thinner and lighter top edge ring 990 in combination with edge ring 950″, edge ring 990 can be removed when edge ring 990 wears out because edge ring 990 is less thick and lighter.

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

[0176] 9F , which illustrates an edge ring 950 ′ similar to the top edge ring 950 of FIG. 9C but with tighter tolerances. In some examples, the gap between edge rings is greater than 0.01 mm and less than or equal to 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 less than 500 μm, 400 μm, or 350 μm. In some examples, the base height (e.g., 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, edge rings 950 ′, 980 , and 970 are made of quartz, although other materials may also be used.

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

[0178] Referring now to Figures 10A and 10B , instead of relying on a capacitor with a conductive edge ring, the edge ring can be made of a dielectric material and can include embedded conductors without external connectors. For example, in Figures 10A and 10B , edge ring 920 from Figures 9A and 9B can be made of a dielectric material and can include embedded conductors 1008 made of metal. Top edge ring 910 is made of a conductive material.

[0179] Embedded conductor 1008 includes a vertical conductive portion 1010 and a horizontal conductive portion 1020. Embedded conductor 1008 is arranged to provide a relatively constant capacitance as top edge ring 910 rises due to wear, as shown in FIG10B . In the example of FIG10A and FIG10B , horizontal conductive portion 1020 provides coupling to heater plate 132. As top edge ring 910 moves upward due to wear, horizontal conductive portion 1020 maintains coupling to heater plate 132. As a result, the capacitance of the transfer member remains substantially constant.

[0180] Referring now to Figures 11A and 11B , edge ring 840 is made of a dielectric material (rather than a conductive material as in Figures 8A and 8B above) and includes an embedded conductor 1108 with no external connections. Top edge ring 810 is made of either a conductive or dielectric material. Embedded conductor 1108 includes an upper horizontal conductor 1110 disposed proximate to and parallel to the lower surface of top edge ring 810. Upper horizontal conductor 1110 connects to a vertical conductor 1112 extending near the center of middle edge ring 840. Vertical conductor 1112 connects to horizontal conductor 1120, which extends radially inward and connects to vertical conductor 1122. Vertical conductor 1122 is disposed near the lower portion near and along the radially inner surface of edge ring 840.

[0181] In FIG11B , when edge ring 840 is raised to compensate for wear of top edge ring 810, the coupling between vertical conductor 1112 and top edge ring 810 remains relatively constant (and less than or equal to DA). Similarly, the coupling between vertical conductor 1122 and the conductive opposing surface of base plate 130 remains relatively constant (and less than or equal to DA). In other locations, the embedded conductors have a gap distance greater than or equal to DB.

[0182] Referring now to Figures 11C to 11E , which illustrate the arcuate portion of edge ring 840, edge ring 840 can be fabricated from a plurality of stacked and sintered ceramic green sheets. Prior to sintering, vertical conductors or through-holes are created by cutting holes in adjacent ceramic green sheets and filling the holes with a conductive material (e.g., conductive paste). In some examples, tungsten paste is used. Horizontal conductors are formed by printing traces or conductive surfaces on the ceramic green sheets using a conductive material. In some examples, the horizontal conductors are printed so as to overlap and contact the vertical conductors, providing a connection therebetween.

[0183] In FIG11C , vertical conductors 1112 or vias are shown connected to conductive plane 1150, which defines horizontal conductors 1110. In FIG11D , vertical conductors pass through the ceramic green sheet at locations where there are no horizontal conductors. In FIG11E , instead of using the conductive plane shown in FIG11D , multiple traces 1160 can be used in place of conductive plane 1150 to implement horizontal conductors 1110.

[0184] Referring now to Figures 12A and 12B , the top edge ring 710 of Figure 7 can be made of a dielectric material instead of a conductive material. The top edge ring 710 includes an embedded conductor 1208 with no external connections. The embedded conductor 1208 includes a horizontal conductor 1210 running 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 the dielectric material to wear away without exposing the horizontal conductor 1210. A vertical conductor 1220 extends vertically near the middle of the top edge ring 710. The vertical conductor 1220 connects to the horizontal conductor 1210 and a horizontal conductor 1224 running parallel to the bottom surface of the top edge ring 710. The horizontal conductor 1224 allows for capacitive coupling to the lift pins 754. The lift pins 754 are made of a conductive material. As shown in Figure 11B , when the top edge ring 710 is raised, the coupling between the lift pins 754 and the horizontal conductor 1224 remains constant.

[0185] 13A and 13B , edge ring 840 is made of a dielectric material or a 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 material or a dielectric material.

[0186] In this example, the top surface 1320 of edge ring 840, located below top 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 edge ring 840 is doped to a predetermined depth to make the dielectric material more conductive from top surface 1320 to the bottom edge of lower surface 849. Top surface 1320 and 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 areas. In FIG13B , when the middle edge ring is raised due to wear of the top edge ring 810, the conductive portion of edge ring 840 provides uniform coupling to adjacent surfaces.

[0188] Referring now to FIG. 14A , top edge ring 1410 is positioned above edge rings 1412 , 1416 , and 1420 . Top edge ring 1410 has an inverted "U" shape and includes an annular body 1434 , radially inner legs 1432 , and radially outer legs 1436 . Annular body 1434 has a thickness t to allow for sufficient material for edge ring stability during processing and sufficient material to allow for a sufficient number of cycles before replacement due to corrosion. In some examples, thickness t ranges from 0.5 mm to 10 mm, although other thicknesses may be used. In some examples, thickness t ranges from 0.5 mm to 5 mm, although other thicknesses may be used.

[0189] The top surface 1438 of the radially outer leg 1436 slopes linearly downward (forming an inclined surface) near the middle 1438' of the top edge ring 1410 to the radially outer edge of the top edge ring 1410. Inclined portion 1438' slopes linearly downward at 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 the point where the downward slope of the top surface 1438 begins. In some examples, depending on the thickness t, the horizontal distance h ranges from 0 mm to 10 mm, although other horizontal distances may be used. In some examples, d is greater than or equal to t. In some examples, d ranges from t to 3t. In some examples, d is less than or equal to t. In some examples, d ranges from 0.25*t to t. Edge rings 1412 and 1416 have L-shaped cross sections.

[0190] In some examples, top surface 1438 has a total thickness H. In some examples, the total thickness H of the edge ring is in a range of 5 mm to 20 mm. In some examples, distance d is greater than or equal to 5%, 10%, 20%, 30%, 40%, or 50% of height H. In some examples, inclined portion 1438' is linearly inclined at an acute angle. In some examples, inclined portion 1438' is inclined at an acute angle in a range of 20° to 70°.

[0191] Edge ring 1410 is substantially taller than previous edge rings to allow for longer wear and conform to the "U" shape. Due to wear, the edge ring may crack if there is insufficient material between the "U" shape and top surfaces 1438 and 1438'. As can be seen, removing material from the radially outer inclined portion reduces the weight of edge ring 1410, which reduces the load on the actuator. This allows the actuator to provide finer adjustment. Compared to a stepped design, the linear slope of inclined portion 1438' increases the amount of material that can be removed without removing too much material between the "U"-shaped groove and top surfaces 1438 and 1438'. In some examples, distance d is greater than the thickness t of ring body 1434 to increase the amount of material removed. In some examples, horizontal distance h is less than the thickness t of ring body 1434 to increase the amount of material removed.

[0192] Edge ring 1412 is located radially outward from edge ring 1416 and below top edge ring 1410. Edge ring 1412 includes upwardly projecting legs 1448 and legs 1446 extending radially inward from upwardly projecting legs 1448. Edge ring 1416 is located adjacent to heater plate 132, radially inward from edge ring 1412, and below substrate 128. Edge ring 1416 includes upwardly projecting legs 1440 and legs 1442 extending radially outward from upwardly projecting legs 1440.

[0193] Edge ring 1420 includes a radially outer portion 1452 and a radially inner portion 1454 extending radially inward from a lower portion of radially outer portion 1452. When lowered, step surface 1455 supports radially outer leg 1436 of top edge ring 1410. Upward protrusion 1456 extends upward from the inner upper surface of radially inner portion 1454. Lift pins 1460 move in response within vertical holes in radially inner portion 1454 of edge ring 1420 to raise and lower edge ring 1410.

[0194] Referring now to FIG. 14B , top edge ring 1410 includes another upper surface profile. An inclined portion 1464′ of the top surface of edge ring 1410 slopes downward in a radially outward direction. Inclined portion 1464′ transitions to a surface 1466 that is generally parallel to a plane including base plate 128. Removing material from the edge ring in inclined portion 1464′ reduces the weight of top edge ring 1410. This weight reduction can be achieved to allow for use with lift actuators having lower lift capabilities.

[0195] 14C , a gap is defined between the radially inner edge 1470 of the top edge ring 1410 and the radially outer surface of the upwardly projecting legs 1440 of the edge ring 1416. This gap is increased relative to the edge ring system of FIGS. 14A and 14B .

[0196] Referring now to FIG. 15 , the edge ring system includes a top edge ring 1510, an outer edge ring 1520, and an edge ring 1530. Edge ring 1530 is located below top edge ring 1510 and radially inward of outer edge ring 1520. Top edge ring 1510 includes a generally rectangular body 1514 and radially inwardly projecting legs 1516 extending from the radially inner and upper surface of top edge ring 1510. Edge ring 1530 is generally rectangular and includes an annular recess 1534 located on its upper and radially inner surface. Base plate 128 is received in annular recess 1534. Outer edge ring 1520 includes a radially outer portion 1522 and an inner portion 1524 extending radially inward from a central portion of radially outer portion 1522. Lift pins 1560 move in response to vertical holes in inner portion 1524 of outer edge ring 1520. The protrusion 1526 extends upwardly from the radially inner and upper surface of the outer edge ring 1520. The generally rectangular body 1514 of the top edge ring 1510 is received on the 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 inclined portion 1518'. The inclined portion 1518' slopes downward from the top surface 1518 to the radially outer edge of the top edge ring 1510 at a distance d. In some examples, the distance d is greater than or equal to 5%, 10%, 20%, 30%, 40%, or 50% of the height H. In some examples, the inclined portion 1518' slopes downward at an acute angle. In some examples, the inclined portion 1518' slopes at an acute angle ranging from 20° to 70°. It will be appreciated that the material removed to create the inclined 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 heater plate 132 has a cylindrical center portion 1577 and a protrusion 1579 extending radially outward from the bottom of the cylindrical center portion. In some examples, the heater plate 132 does not include an RF electrode. In other examples, the RF electrode is removed from the heater plate 132 near the edge ring. For example, the RF electrode is removed from region 1580 of the heater plate below the edge ring 1530.

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

[0200] Edge ring 1620 includes an annular body 1622. Radially outwardly projecting legs 1624 extend from the upper and radially outer surface of annular body 1622. Radially inwardly projecting legs 1628 extend radially inward from the radially inner and lower surface of annular body 1622. Edge ring 1620 is located radially outward of top edge ring 1610.

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

[0202] Edge ring 1640 is located below edge ring 1620 and radially outward from the lower portion of edge ring 1630. Edge ring 1640 includes an annular body 1642 and radially downwardly projecting legs 1644 extending from the radially outer and lower surface of annular body 1642. Inwardly projecting legs 1646 extend radially inward from the center and interior of annular body 1642. Inwardly projecting legs 1646 include vertical holes 1647 that receive lift pins 1648. Edge ring 1640 includes an annular recess 1650 and a protrusion 1652 that define a vertical hole in the lower surface of edge ring 1640 to receive a guide sleeve 1660 disposed in a vertical hole 1664 in base plate 130. Edge ring 1640 includes an annular recess 1654 on its lower and radially inner surface to provide clearance from the radially outer edge of base plate 130.

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

[0204] 16B , when lift pins 1648 are fully lowered, edge ring 1630 defines a third vertical gap 1680 between the lower surface of edge ring 1610 and the upper surface of edge ring 1630. The lower surface of edge ring 1630 rests on the upper surface of radially inwardly projecting legs 1646. During operation, edge ring 1630 can be positioned adjacent to edge ring 1610 by raising lift pins 1648, or spaced apart from edge ring 1610 by lowering lift pins 1648 and edge ring 1630.

[0205] When edge ring 1610 is worn due to exposure to the plasma, substrate 128 is removed and lift pins 1648 raise edge ring 1630 and edge ring 1610 upward, as shown in FIG16C . Edge ring 1610 is removed from the processing chamber through the substrate port using a robot (e.g., a vacuum transfer module robot). Another edge ring 1610 is transferred (using a robot through the substrate port) onto edge ring 1630, and lift pins 1648 are lowered. In some examples, top ring 1610 is made of a conductive or dielectric material, ring 1630 is made of a conductive material or a dielectric material with embedded electrodes, and rings 1620 and 1640 are made of a dielectric material.

[0206] Referring to FIG. 16D , edge ring 1640 of FIG. 16A-16C can be split into two concentric rings. Inner ring 1680 includes an annular body 1682 and an annular recess 1684 (similar to annular recess 1650 in FIG. 16A-16C ) located on its lower, radially inner surface. Inner ring 1680 is made of a conductive material to enhance capacitive coupling with edge ring 1630. This arrangement allows for greater RF transmission between base plate 130 and 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 outside the inner ring 1680. The radial inner surface 1694 of the outer ring 1690 is adjacent to the radial outer surface 1686 of the inner ring 1680.

[0208] Referring now to Figures 17 and 18, many of the aforementioned examples include an upper ring exposed to the plasma and a lower ring located below and shielded from direct plasma exposure by the upper ring. For example, a cross-section of a portion of an edge ring system 1700 designed for capacitive coupling is shown in Figure 17. The lower portion of upper ring 1710 is located radially outward of the lower portion of lower ring 1720.

[0209] To maintain control of the plasma sheath at low bias frequencies, the value of coupling capacitor C should remain fixed and relatively constant as upper ring 1710 is exposed to plasma, corroding and increasing in height. Furthermore, there may be a significant temperature difference between upper ring 1710 and lower ring 1720. For example, during plasma processing, the temperature difference between upper ring 1710 and lower ring 1720 may range from 0°C to 200°C (e.g., 100°C). In some examples, because lower ring 1720 expands when heated and contracts when cooled, lower ring 1720 (or upper ring 1710) may move or traverse toward the side of upper ring 1710 in a direction parallel to the substrate, effectively reducing the gap in some radial directions and increasing the gap in other radial directions.

[0210] Assuming C is the capacitance between the upper ring 1710 and the lower ring 1720, as the lower ring 1720 moves away from the 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 because the capacitance is a nonlinear function of the gap. More specifically, capacitance C shifted = S(s')*C centered, where s' = d / (R 2 - R 1), where 0 [<]s' [<]1, where R2 is the inner diameter of the upper ring 1710 and R1 is the outer diameter of the lower ring 1720. In FIG18 , the relative increase in capacitance is shown as a function of the percentage deviation (%) from the nominal gap. It can be seen that when the percentage deviation is greater than approximately 35-40% of the nominal gap, the capacitance is affected.

[0211] Systems and methods according to the present invention use spacers (e.g., shims, pins, or protrusions) on either the upper ring or the lower ring 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 less than or equal to 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 , which illustrate various ways to limit movement of the upper ring relative to the lower ring of an edge ring system. In FIG19 , edge ring system 1900 includes upper ring 1910, which includes inner and outer portions 1910-1 and 1910-2, respectively, located adjacent to the radially inner and outer surfaces of lower ring 1920. In FIG20-22 , various ways to limit movement of upper ring 1910 relative to lower ring 1920 are illustrated.

[0213] In FIG20 , lower ring 1920 includes a slot 1938 on its radially outer surface. Slot 1938 extends radially inward to the radially outer surface of lower ring 1920. A shim 1934 is disposed in slot 1938. In some examples, adhesive 1930 is used to retain shim 1934 in slot 1938. In some examples, shim 1934 has a rectangular planar, radial, and lateral cross-section, although other shapes may be used. In some examples, the radial thickness of shim 1934 is greater than or equal to the depth of slot 1938. In some examples, shim 1934 extends radially outward from lower ring 1920 to a distance sufficient to limit movement (taking into account the number of shims used).

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

[0215] In Figures 22A and 22B, lower ring 1920 includes protrusions 1960 formed on its radially outer surface. In some examples, protrusions 1960 extend vertically, partially or entirely along the vertical thickness of the radially outer surface. In Figure 22B, protrusions 1960 include flat surfaces 1963 extending from radially outer surface 1962 of lower edge ring 1920, which are easier to machine and inspect for dimensions than an arcuate profile. In other words, in some examples, the edge ring is initially formed slightly wider without protrusions 1960, and then the radially outer surface is machined or removed in the areas between adjacent protrusions to form protrusions 1960. In other examples, protrusions 1960 include an arcuate or convex profile in plan view to reduce the surface area in contact with the radially inner opposing surface of the top edge ring and reduce friction when performing height adjustments or replacing the top edge ring without breaking vacuum.

[0216] In some examples, protrusion 1960 is coated with a coating material 1964. In some examples, 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. Coating material 1964 provides insulation, preventing short circuits and reducing corrosion. Coating material 1964 also ensures a minimum gap between lower ring 1920 and upper ring 1910 to prevent short circuits. In some examples, protrusion 1960 extends radially outward from the radially outer surface of lower ring 1920 to a distance sufficient to limit movement (taking into account the number of protrusions used).

[0217] In some examples, lower ring 1920 includes 3 to 8 spacers (shims, pins, or protrusions) arranged around the outer perimeter of lower ring 1920 at uniform spacing (e.g., 3 at 120° spacing, 5 at 72° spacing, and 8 at 45° spacing (or 360° / N)). It will be appreciated that the spacers are generally not configured to completely restrict relative movement between the upper and lower rings. The gap helps reduce engagement during height adjustment and / or replacement. Therefore, some relative movement is still desirable, while 3 shims may still allow for undesirable movement (which could change the effective coupling capacitance). In some examples, lower ring 1920 includes 5 spacers arranged around the outer perimeter of lower ring 1920 to further restrict movement. Depending on the specific configuration, additional spacers (e.g., 6, 7, or 8) provide diminishing benefits in controlling effective capacitance and increase cost.

[0218] Although spacers (e.g., shims, pins, or protrusions) are shown as being disposed on the outer surface of the lower ring 1920, the spacers may be disposed on the inner surface of the lower ring 1920 and / or one or both inner surfaces of the upper ring 1910. Additionally, spacers and / or an insulating coating may be disposed on any of the aforementioned examples (e.g., in Figures 1-22) on one or both diametrically opposed surfaces of the edge ring used for capacitive coupling.

[0219] In some examples, the spacer extends in a radially outward direction from the radially outer surface of the edge ring by a range of 50 μm to 250 μm. In some examples, the spacer extends in a radially outward direction from the radially outer surface of the edge ring by a range of 50 μm to 250 μm.

[0220] The foregoing is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. The broad teachings of this disclosure can be implemented in many ways. Therefore, while this disclosure includes specific examples, the true scope of the invention should not be so limited, as other variations will become apparent upon study of the drawings, the specification, and the following claims. It should be understood that one or more steps in a method can be performed in a different order (or simultaneously) without altering the principles of the invention. Furthermore, while various embodiments have been described above as having certain features, any one or more of such features described with respect to any embodiment of the invention may be implemented in combination with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments for one another remains within the scope of the invention.

[0221] Spatial and functional relationships between components (e.g., modules, circuit elements, semiconductor layers, etc.) are described using a variety of terms, including "connected," "joined," "coupled," "adjacent," "adjacent," "above," "over," "above," "below," and "disposed." When describing a relationship between a first and second component in the above disclosure, unless explicitly described as "direct," the relationship may be a direct relationship with no intervening components between the first and second components, or an indirect relationship with one or more intervening components (spatially or functionally) between the first and second components. As used herein, the phrase "at least one of A, B, and C" should be understood to mean a logical (A or B or C) using a non-exclusive logical "OR" and should not be understood to mean "at least one of A, at least one of B, and at least one of C."

[0222] In some embodiments, a controller is part of a system, which may be one of the examples described above. Such systems may include semiconductor processing equipment, which may include 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 combined with electronics to control operations before, during, and after processing of semiconductor wafers or substrates. Such electronics may be referred to as "controllers" and may control various components or subcomponents of the system or systems. Depending on the processing requirements and / or system type, the controller may be programmed to control any of the processes disclosed herein, including process gas delivery, 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 operation settings, and wafer transfer (in and out of tools connected or interfaced with the particular system, other transfer tools, and / or load chambers).

[0223] Broadly speaking, a controller can be defined as an electronic device having integrated circuits, logic, memory, and / or software for receiving commands, issuing commands, controlling operations, initiating cleaning operations, initiating endpoint measurements, and the like. Integrated circuits can include chips in the form of firmware storing program instructions, digital signal processors (DSPs), chips defined as application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions can be sent to the controller in the form of individual settings (or program files) that define operating parameters for executing a specific process (on a semiconductor wafer, for a semiconductor wafer, or for a system). In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to achieve one or more processing steps during the manufacture of one or more of the following: layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0224] The controller may in some embodiments be part of, or coupled to, a computer that is integrated with the system, coupled to the system, connected to the system in the manner of other networks, or a combination thereof. For example, the controller may be in all, or part of a ”cloud” or factory host computer system that allows remote access to wafer processing. The computer enables the system to be remotely accessed to monitor the current progress of a manufacturing operation, check the history of past manufacturing operations, check trends or performance measures from plural manufacturing operations to change the parameters of the current processing, set the processing steps after the current processing, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system via a network that may include a local area network or an Internet network. The remote computer may contain a user interface capable of parameter and / or setting input or programming, which can then be transmitted from the remote computer to the system. In some examples, the controller receives a data form instruction that specifies parameters for each processing step that is about to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be executed, and the type of tool to which the controller is engaged or controlled. Thus, as described above, the controller may be decentralized, such as by means of a controller comprising one or more separate controllers connected together in a network manner and operating toward a common purpose (e.g., processes and control described herein). Distributed controllers for this purpose An example is one or more integrated circuits on the chamber communicating with one or more integrated circuits located at a remote end (e.g., at the level of the platform, or as part of a remote computer), which are combined to control the process on the chamber.

[0225] Exemplary systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, rotary cleaning chambers or modules, metal-coated chambers or modules, cleaning chambers or modules, beveled edge etching chambers or modules, physical gas phase deposition (PVD) chambers or modules, chemical gas phase deposition (C VD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, orbital chambers or modules, and any other semiconductor processing system that may be associated with, or used, in the manufacture and / or processing of semiconductor wafers.

[0226] As mentioned above, depending on the process steps or plural steps to be performed with recourse to the tool, the controller may communicate with one or more of the following in a semiconductor manufacturing plant: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, adjacent tools, tools distributed throughout the plant, a master computer, another controller, or a tool used in a material conveying, the tool port used in or to and from the tool port in the material transportation carries the wafers / ports to and from.

[0227] 110: Substrate processing system 122: Processing chamber 124: Upper electrode 126: substrate support 128:Substrate 129: Gas distribution device 130: Bottom plate 132: Heating plate, heating layer 134: bonding and / or thermal resistance layer 136: Channel 140:RF generation system 142: RF generator 144: Matching and Distribution Network 150:Gas delivery system 152-1: Gas Source 152-2: Gas Source 152-N: Gas Source 154-1: Valve 154-2: Valve 154-N: Valve 156-1: Mass Flow Controller 156-2: Mass Flow Controller 156-N: Mass Flow Controller 160: Manifold 163: Temperature Controller 164: Thermal control element 166:Coolant assembly 170: Valve 172: Pump 180: System Controller 182:Edge Ring 184:Edge ring height adjustment system 190: Upper surface 210: Substrate processing system 211: Coil drive circuit 212: RF source 213: Tuned Circuit 214: Pulse Circuit 216: Coil 220: Air Chamber 224: Dielectric Window 228: Processing chamber 232: substrate support 240: Plasma 252: RF drive circuit 254:Controller 256:Gas Delivery System 257: Gas Source 258:Gas Metering System 259: Manifold 260:Gas Delivery System 261: Valve 262: Gas 264: Heater / Cooler 265: Exhaust system 266: Valve 267: Pump 310: Top edge ring 314: Middle edge ring 316: Bottom edge ring 330: Ring 332: radial inner foot 334: Radial outer support foot 340: Ring 342: Radial inner support foot 344: Radial outer support foot 350: radial outer 352: Middle 354: radial inner 360: annular recess 364: annular recess 372: Lifting pin 374: Extended vertical hole 376: Extended vertical hole 380: Plasma 390: Sheath 392:Transmission component 410: Electrostatic electrode 412: Radiofrequency electrode 420: Top edge ring 422: radial inner foot 424: Ring 426: radial outer leg 430: Middle edge ring 432: Radial outer support leg 436: Ring 438: Radial inner support foot 440: Bottom edge ring 444: Middle 446: Upper part 448:lower part 450: radial inner 452: upward protrusion 456: Steps 462: Cavity 464: Cavity 470: Lifting pin 610:Edge Ring 612:Inner legs 614: Ring 616:External support legs 618: concave part 620: Top edge ring 622:Inner legs 624: Ring 626:External support legs 630:Edge Ring 630': Edge Ring 630'':Edge ring 632: Upper part 634: Middle 636: radially outward protrusion 637:Inner surface 638: protrusion 639: Relative surface 640:Edge Ring 641: radial outer surface 642: Subject 644: Upper part 646:lower part 648: protrusion 650: Outer edge ring 652: Subject 654: radially inward protrusion 656: downward protrusion 658: annular recess 659: annular recess 660: Ring seal 661: Annular groove 662: Lifting pin 664:Guide Kit 666: Vertical hole 690: Vertical clearance 691: Horizontal gap 710: Top edge ring 720: Middle edge ring 722: Vertical legs 726: radially outward protruding legs 740: Bottom edge ring 742: upward protrusion 744: Ring 745: Inward protrusion 746: Vertical hole 747: Upward protrusion 748: downward protrusion 749: downward protrusion 750:Guide Kit 754: Lifting pin 810: Top edge ring 812: Ring 814:Inner legs 816:External support legs 820: Outer edge ring 822: Middle part 824:lower part 826: annular recess 828: Upper part 829: Steps 840:Edge Ring 842: Middle part 843: Upper part 844:lower part 846: annular recess 848: annular recess 849: Lower surface 850:Edge Ring 852: Main body 854: Steps 870:Edge Ring 872: Upper part 874:lower part 876: Ring seal 880:Edge Ring 882: annular recess 884: Top edge ring 885: Ring 886: Radial inner foot 888: Radial outer legs 892: Outer edge ring 894: annular recess 896: annular recess 910: Top edge ring 912: Ring 914:Inner legs 916:External support legs 920:Edge Ring 922: Pointing upwards 924: radially inward pointing feet 930:Edge Ring 932: Pointing feet upwards 934: radially outward pointing feet 940: Bottom edge ring 942: Middle part 944: pointing upward 946: radial inner 948: pointing downward 949: upward pointing protrusion 950: Top edge ring 952: Radial inner foot 954: Ring 956: Radial outer support foot 957: Radial recess 958: Beveled lower surface 960:Edge Ring 962: Radial inner foot 964: Radial outer support foot 966: Ring 970:Edge Ring 971:Conforming seals 972: radial inner 973: annular recess 974: annular recess 975:Protrusion 976: First annular recess 978: Second annular recess 980:Edge Ring 982: Vertical legs 984: radially inward protruding feet 986:Edge Ring 988: annular recess 990:Edge Ring 992: radially inward protruding feet 994: downward protruding feet 995: External edge ring 996:Protrusion 997:Edge Ring 998: annular recess 999:Protrusion 1008:Embedded conductor 1010: vertical conductive portion 1020: horizontal conductive part 1108:Embedded conductor 1110: horizontal conductor 1112: Vertical conductor 1120: horizontal conductor 1122: Vertical conductor 1160: trace 1208:Embedded conductor 1210: Horizontal conductor 1220: Vertical conductor 1224: Horizontal conductor 1320: Top surface 1322: radial inner surface 1410: Top edge ring 1412:Edge Ring 1416:Edge Ring 1420:Edge Ring 1432: Radial inner foot 1434: Ring 1436: Radial outer support foot 1438: Top surface 1438': inclined part 1440: Upward protruding feet 1442: Legs 1446: Legs 1448: Upward protruding feet 1452: radially outer 1454: Radial inner 1455: Step surface 1456: Upward protrusion 1460:Lifting pin 1464: inclined portion 1466: Surface 1470: radial inner edge 1510: Top edge ring 1514: roughly rectangular 1516: radially inward protruding feet 1518: Top surface 1518': inclined part 1520: Outer edge ring 1522: radially outer 1524: Internal 1526:Protrusion 1530:Edge Ring 1534: annular recess 1555: Upper surface 1560:Lifting pin 1577: Cylindrical center 1579: The Prominence 1580: Area 1600: Removable edge ring system 1610: Top edge ring 1612: Ring 1616: Radial inner foot 1618: Inward protruding feet 1619: annular recess 1620:Edge Ring 1622: Ring 1624: radially outward protruding feet 1630:Edge Ring 1632: Ring 1633: Spacer 1634: radially inward protruding feet, radially inner feet 1640:Edge Ring 1642: Ring 1644: radially downward protruding feet 1646: Inward protruding feet 1647: Vertical hole 1648:Lifting pin 1650: annular recess 1652:Protrusion 1654: annular recess 1660:Guide Kit 1664: Vertical hole 1670: First vertical gap 1672: Second vertical gap 1680:Inner Ring 1682: Ring 1684: annular recess 1686: radial outer surface 1690: External ring 1692: Ring 1694: radial inner surface 1700:Edge Ring System 1710: Upper ring 1720: Lower ring 1900: Marginal Ring System 1910: Upper ring 1910-1: Upper ring 1910-2: Upper ring 1920: Lower ring 1930: Adhesives 1934: Gasket 1938: Slot 1948: Slot 1950: Sales 1960:Protuberance 1962: Radial outer surface 1963: Flat Surface 1964: Coating Materials

Claims

1. A top edge ring configured to rise and fall relative to an intermediate edge ring and a bottom edge ring in a plasma processing system, the top edge ring system comprising: An annular body includes a top surface and a bottom surface, the top surface being configured to face plasma, and the bottom surface being positioned relative to the top surface; a radially inner support extending from the bottom surface of the annular body in a direction perpendicular to the top surface; a radially outer support extending from the bottom surface of the annular body at a position radially outwardly separated from the radially inner support, and in a direction perpendicular to the top surface, wherein the radially inner support extends from the annular body by a first distance, and the radially outer support extends from the annular body by a second distance, the second distance being greater than the first distance; wherein a cavity located between the radially inner support and the radially outer support is configured to receive the radially outer support of an intermediate edge ring; and N radially recessed portions extending radially outwardly into a lower portion and radially inner surface of the radially outer support, wherein the N radially recessed portions are configured to receive N lifting pins respectively, for moving the top edge ring relative to the intermediate edge ring and the bottom edge ring, wherein N is an integer greater than 2.

2. The top edge ring as described in claim 1, wherein, The radial thickness of the outer radial support is P times thicker than the radial thickness of the inner radial support, where P is greater than or equal to 2 and less than or equal to 5.

3. The top edge ring as described in claim 1, wherein: The top edge ring is configured to move a predetermined distance relative to the middle edge ring and the bottom edge ring between a lowest position and a highest position before replacement due to wear of the top edge ring, and the difference between the second distance and the first distance is greater than or equal to the predetermined distance.

4. The top edge ring as described in claim 1, wherein, When the top edge ring moves from a lowest position to a higher position due to wear on the top surface of the top edge ring, the areas of at least one opposing surface of the top edge ring and the middle edge ring remain the same.

5. The top edge ring as described in claim 1, wherein, The top edge ring is made of a conductive material.

6. The top edge ring as described in claim 5, wherein, The conductive material is selected from the group consisting of quartz, silicon carbide, silicon, or combinations thereof.

7. The top edge ring as described in claim 1, wherein, The N radial recesses are separated around the annular body at 360° / N.

8. The top edge ring as described in claim 1, wherein, The N radial recesses further include one or more beveled surfaces.

9. The top edge ring as described in claim 8, wherein, The one or more beveled surfaces of the N radial recesses are configured to center the top edge ring relative to at least one of the middle edge ring and the bottom edge ring.

10. The top edge ring as described in claim 8, wherein, The one or more beveled surfaces of the N radial recesses are contained within a first beveled surface that is inclined in a radial direction.

11. The top edge ring as described in claim 10, wherein, The first beveled surface forms an acute angle with respect to the bottom surface of the radially outer support.

12. The top edge ring as described in claim 8, wherein, The one or more beveled surfaces of the N radial recesses comprise a first surface and a second surface that are inclined in a circumferential direction.

13. The top edge ring as described in claim 12, wherein, The angle between the first surface and the second surface is in the range of 75° to 105°.

Images