Movable Edge Ring for Plasma Processing System

Abstract

The edge ring system includes a movable upper ring and a cover ring configured to be disposed above and radially outward of the movable upper ring. The cover ring includes an annular body and a stepped portion extending radially inward from the annular body. The stepped portion is configured to extend above the outer edge of the movable upper ring. An annular recess is defined at the inner radius of the cover ring below the stepped portion. The movable upper ring includes an annular body and a curved outer radius. A ring centering portion is formed in the lower surface of the annular body and is configured to center the movable upper ring on a movable support ring.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of U.S. Provisional Application No. 63 / 358,054, filed on July 1, 2022. The entire disclosure of the application referenced above is incorporated herein by reference.

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

Background Art

[0003] The description of the background art provided herein is for the purpose of generally presenting the context of the present disclosure. The research of the inventors, as currently named, is not admitted, either explicitly or implicitly, as prior art to the present disclosure, to the extent that it may not be considered separate from the prior art at the time of filing in the scope of the research described in this background art section.

[0004] A substrate processing system performs processing on a substrate such as a semiconductor wafer. Examples of substrate processing include deposition, ashing, etching, cleaning, and / or other processes. To process the substrate, a process gas mixture may be supplied to the processing chamber. Plasma may be used to ignite the gas to enhance chemical reactions.

[0005] The substrate is placed on a substrate support during processing. An edge ring has an annular body disposed around and adjacent to the radially outer edge of the substrate. The edge ring may be used to shape or focus plasma on the substrate. During operation, the substrate and the exposed surface of the edge ring are etched by the plasma. As a result, the edge ring wears, and the effect of the edge ring on the plasma changes, which can adversely affect uniformity.

Summary of the Invention

[0006] A covering for an edge ring system is configured to be disposed above and radially outward of a movable upper ring of the edge ring system. The covering includes an annular body and a stepped portion extending radially inward from the annular body. The stepped portion is configured to extend above an outer edge of the movable upper ring of the edge ring system. An annular recess is defined at an inner radius of the covering below the stepped portion. The annular recess is configured to receive the outer edge of the movable upper ring, and a height of the annular recess is at least 60% of an overall height of the covering.

[0007] In other features, the covering is composed of a non-conductive material. The height of the annular recess is at least 75% of an overall height of the covering. A width of the annular recess is at least 32% of a width of the annular body. An inner radius of the covering is curved. The inner radius has a radius of curvature between 0.070 inches and 0.090 inches. The height of the annular recess is at least 63% of an overall height of the covering. The width of the annular recess is at least 32% of a width of the annular body.

[0008] A movable upper ring for an edge ring system includes an annular body and a curved outer radius. A ring centering portion is formed in a lower surface of the annular body and is configured to center the movable upper ring on a movable support ring. The lower surface includes downward projections disposed at a radially inner location and a radially outer location of the annular body to define the ring centering portion.

[0009] In other features, the ring centering portion forms a cavity in the lower surface of the annular body, and the downward projections are disposed on both sides of the cavity. An inner sidewall of the ring centering portion is substantially vertical. The outer radius has a radius of curvature between 0.070 inches and 0.090 inches. A width of the ring centering portion is at least 75% of a width of the annular body. A depth of the ring centering portion is at least 26% of an overall height of the movable upper ring.

[0010] A bottom ring for an edge ring system is configured to support a cover ring of the edge ring system. The bottom ring includes an annular body, a first protrusion extending radially inward from an upper portion of the radially inner surface of the annular body, an annular recess defined in the radially inner surface of the annular body above the protrusion, the annular recess being configured to support the cover ring, and a second protrusion extending radially outward from an upper portion of the radially outer surface of the annular body.

[0011] In another feature, the height of the annular recess is at least 6% of the overall height of the bottom ring.

[0012] An edge ring system includes a bottom ring, a cover ring, and a movable upper ring. The bottom ring includes an annular body, a protrusion extending radially inward from an upper portion of the radially inner surface of the annular body of the bottom ring, and an annular recess defined in the radially inner surface of the annular body above the protrusion. The cover ring is disposed above and radially inward of the bottom ring and is supported on the protrusion within the annular recess of the bottom ring. The cover ring includes an annular body, a stepped portion extending radially inward from the annular body of the cover ring, and an annular recess defined at the inner radius of the cover ring below the stepped portion. The movable upper ring is disposed below and radially inward of the cover ring. The movable upper ring includes an annular body and a ring centering portion. A radially outer portion of the annular body of the movable upper ring extends below the cover ring to reach the annular recess of the cover ring, and the ring centering portion is formed in the lower surface of the annular body of the movable upper ring.

[0013] In other features, the inner sidewall of the ring centering portion is substantially vertical. The movable upper ring further includes an annular recess disposed on the upper side and the radially outer portion of the annular body. The annular recess is defined by an outer sidewall and a downward step, and the outer sidewall is substantially vertical. The downward projections are disposed at the radially inner location and the radially outer location of the lower surface to define the ring centering portion. The movable upper ring includes a curved outer radius. The outer radius has a radius of curvature between 0.070 inches and 0.090 inches.

[0014] In other features, the annular recess of the cover ring is configured to receive the outer edge of the movable upper ring, and the height of the annular recess of the cover ring is at least 70% of the overall height of the cover ring. The inner radius of the cover ring is curved. The inner radius has a radius of curvature between 0.070 inches and 0.090 inches. The edge ring system further includes an inner ring disposed below and radially inward of the movable upper ring. The inner ring has an "L"-shaped cross-section that defines an outer annular recess.

[0015] In other features, the outer annular recess is disposed to receive the radially inner edge of the movable upper ring. The outer diameter of the cover ring does not contact the bottom ring. The outer diameter of the movable upper ring does not contact the bottom ring. When in the lowest position, the movable upper ring does not contact any part of the inner ring, the cover ring, or the bottom ring.

[0016] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

Brief Description of the Drawings

[0017] The present disclosure will be more fully understood from the detailed description and the accompanying drawings.

[0018]

Figure 1

[0019]

Figure 2A

[0020]

Figure 2B

[0021]

Figure 2C

[0022]

Figure 2D

[0023]

Figure 2E

[0024]

Figure 2F

[0025]

Figure 2G

[0026]

Figure 2H

[0027]

Figure 2I

[0028]

Figure 2J

[0029]

Figure 2K

[0030]

Figure 2L

[0031]

Figure 2M

[0032]

Figure 2N

[0033]

Figure 3A

[0034]

Figure 3B

[0035]

Figure 3C

[0036]

Figure 3D

[0037]

Figure 3E

[0038]

Figure 3F

[0039]

Figure 3G

[0040]

Figure 3H

[0041] In the drawings, reference numbers may be reused to identify similar and / or equivalent elements.

DETAILED DESCRIPTION OF THE INVENTION

[0042] During substrate processing, the substrate is placed on a pedestal such as an electrostatic chuck (ESC), a process gas is supplied, and plasma is made to collide in the processing chamber. The exposed surfaces of the components within the processing chamber experience wear due to exposure to the plasma.

[0043] For example, an edge ring is placed around the radially outer edge of the substrate to shape the plasma. After processing the substrate, the exposed surface of the edge ring can be worn and be at a different height relative to the substrate. As a result, the effect of the edge ring on the plasma changes, which changes the effect of the process on the substrate. Thus, in some substrate processing systems, the processing chamber will need to be opened to replace the worn edge ring.

[0044] To reduce process variations due to edge ring wear without breaking the vacuum, some processing chambers are equipped with adjustable edge rings. These processing chambers can increase the height position of the adjustable edge ring to compensate for wear or to allow adjustment for different process conditions in the recipe. This approach increases the time between edge ring replacements, which reduces the replacement cost and decreases the overall downtime.

[0045] As the height position of the edge ring changes, the capacitive coupling between the plasma, sheath, and / or capacitive delivery structure (including the edge ring) also changes. These changes in capacitive coupling can cause substrate processing non-uniformities over time. For example, the change in capacitive coupling causes a change in voltage on components such as the edge ring, which affects the plasma sheath near the edge of the substrate, the slope at the edge of the substrate, etc. Capacitive coupling variations can also occur in response to other factors such as the thermal expansion of the edge ring, erosion of the gap between adjacent rings, and variations between components.

[0046] In some cases, coatings, spacers, and / or minimum gaps are used to minimize capacitance variations. However, these mechanisms can reduce the overall coupling capacitance, which reduces the RF voltage on the edge ring. For example, these mechanisms result in a more consistent but larger gap, which reduces the coupling capacitance and causes the plasma sheath to bend downward. As a result, a higher geometric height for the rings around the base plate will relieve the downward bend of the plasma sheath and promote a more vertical slope. For example, increasing the height of components such as the edge ring, cover ring, etc. can cause the plasma sheath to bend upward.

[0047] Various edge ring configurations according to the present disclosure are configured to reduce capacitive coupling variations as the movable upper ring wears. FIGS. 2A - 2L and FIGS. 3A - 3H show novel edge ring systems / arrangements, adjustable movable upper rings, cover rings, and bottom rings. As further described below, the height position of the movable upper ring relative to the upper surface of the base plate, cover ring, or bottom ring can be changed by moving the movable upper ring up or down using an actuator system such as a movable support ring and lift pins.

[0048] Next, referring to FIG. 1, an example of a substrate processing system 110 that performs plasma processing and includes a movable edge ring system according to some embodiments of the present disclosure is shown. Although a particular type of plasma processing chamber is shown, other plasma processing chambers may be used. The substrate processing system 110 may be used to perform etching using capacitively coupled plasma (CCP). The substrate processing system 110 includes a processing chamber 122 that surrounds other components of the substrate processing system 110 and includes (when used) RF plasma. 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 placed on the substrate support 126.

[0049] Merely by way of example, the upper electrode 124 may include a gas distribution device 129 such as a showerhead for introducing and distributing process gas. The gas distribution device 129 may include a stem portion that includes one end connected to the upper surface of the processing chamber. The annular body is generally cylindrical and extends radially outward from the opposite end of the stem portion at a location spaced from the upper surface of the processing chamber. The surface or faceplate of the annular body of the showerhead facing the substrate includes a plurality of holes through which a precursor, reactant, etch gas, inert gas, carrier gas, other process gas, or purge gas flows. Alternatively, the upper electrode 124 may include a conductive plate, and the process gas may be introduced in another manner.

[0050] The substrate support 126 includes a base plate 130 that acts as a lower electrode. The base plate 130 supports a heating plate 132, which may correspond to a ceramic multi-zone heating plate. A bonding and / or thermal resistance layer 134 may be disposed between the heating plate 132 and the base plate 130. The base plate 130 may include one or more channels 136 for flowing a coolant through the base plate 130.

[0051] 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 may include an RF generator 142 that generates RF plasma power, and the RF plasma power is applied 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.

[0052] The 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 0. The gas sources 152 are connected to a manifold 160 by 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). A secondary valve may be used between the MFCs 156 and the manifold 160. Although a single gas delivery system 150 is shown, two or more gas delivery systems may be used.

[0053] The temperature controller 163 can be connected to a plurality of thermal control elements (TCEs) 164 disposed in 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 communicate with a coolant assembly 166 to control the coolant flow through the channel 136. For example, the coolant assembly 166 may include a coolant pump, a reservoir, and / or one or more temperature sensors. The temperature controller 163 operates the coolant assembly 166 to selectively flow coolant through the channel 136 to cool the substrate support 126.

[0054] Valve 170 and pump 172 can be used to discharge reactants from the processing chamber 122. The system controller 180 can include one or more controllers used to control the components of the substrate processing system 110. In some examples, the movable edge ring 182 is disposed radially outside the substrate 128 during plasma processing and is exposed to the plasma. In other examples, the movable edge ring is located below a fixed edge ring that is exposed to the plasma. The edge ring height position adjustment system 184 can be used to adjust the height position of the upper surface of the movable edge ring 182 relative to the substrate 128 (or to change the RF voltage of the fixed edge ring), as further described below. In some examples, the movable edge ring 182 can also be lifted up, removed by a robot end effector, and exchanged with another edge ring without breaking the vacuum.

[0055] In some embodiments, the system controller 180 controls the robot 190 to send the substrate and / or the edge ring into the processing chamber, as further described below. The system controller 180 also controls one or more actuators 192 that move lift pins to adjust the height position or tilt of the edge ring, as further described below. The system controller 180 can also receive an output from one or more sensors 196 used to detect the height of the edge ring. Non-limiting examples of sensors include optical sensors, physical sensors, piezoelectric sensors, ultrasonic sensors, and the like.

[0056] Referring next to FIG. 2A, an example of an edge ring system 500 includes, among other components, a movable upper ring 504, a cover ring 506, a bottom ring 508, and an inner ring 512. In one embodiment, the movable upper ring 504 is composed of silicon carbide, and the cover ring 506, the bottom ring 508, and the inner ring 512 are composed of quartz.

[0057] Figure 2B is an upper isometric view of the movable upper ring 504. Figure 2C is a bottom isometric view of the movable upper ring 504. Figure 2D is a cross-sectional view of the entire movable upper ring 504. Figure 2E is a cross-sectional view of a part of the body of the movable upper ring 504. Figure 2F is a bottom isometric view of the cover ring 506. Figure 2G is a cross-sectional view of the entire cover ring 506. Figure 2H is a cross-sectional view of a part of the body of the cover ring 506. Figure 2I is an upper isometric view of the bottom ring 508. Figure 2J is a side cross-sectional view of a part of the bottom ring 508. Figure 2K is a side cross-sectional view of the entire bottom ring. Figure 2L is an upper isometric view of the inner ring 512. Figure 2M is a side cross-sectional view of a part of the inner ring 512. Figure 2N is a side cross-sectional view of the entire inner ring.

[0058] The edge ring system 500 also has a movable support ring 516 and a shield ring 520. The movable upper ring 504 is directly exposed to the plasma during processing. When installed, the movable upper ring 504 rests on the movable support ring 516. An actuator 522 biases a lift pin 524 against the lower surface of the movable support ring 516 to adjust the position of the movable upper ring 504 relative to the substrate 526.

[0059] The movable upper ring 504 includes an annular body 540. In some examples, the movable upper ring 504 includes a ring centering portion 542 for centering the movable upper ring 504 on the movable support ring 516. In some examples, the ring centering portion 542 includes a cavity formed on its lower surface. In some examples, the cavity has a width sufficient to receive the upper portion of the movable support ring 516. The downward protrusions 544 and 546 of the movable upper ring 504 are disposed at the radially inner location and the radially outer location of the annular body 540 on both sides of the cavity. In some examples, an annular recess 548 is disposed on the upper and radially outer portion of the annular body 540.

[0060] In some examples, the lower portion of the movable support ring 516 includes a ring centering portion 550 for centering the movable support ring 516 relative to the base plate 552. In some examples, a heating layer 556 (e.g., a ceramic layer) is disposed above the base plate 552. A bonding layer (not shown) may be disposed between the heating layer 556 and the base plate 552. The base plate 552 may be disposed on the support plate 558.

[0061] As can be appreciated, all of the edge ring systems described herein may include a ring centering portion 550. In some examples, the ring centering portion 550 includes a cavity 554 having an inner surface with a portion that is linearly or non-linearly inclined (e.g., curved) so as to bias the movable support ring 516 into a position where the movable support ring 516 is seated on the lift pins 524. In some examples, the surface of the cavity includes opposing surfaces that provide a centering effect. In some examples, the surface of the cavity has a "V" shape, a conical shape, a linear shape, a combination of curved shapes, or other type of surface that provides a centering effect.

[0062] The shield ring 520 includes an annular body that partially surrounds the movable support ring 516. The bottom ring 508 is disposed radially external to the movable upper ring 504, the movable support ring 516, and the shield ring 520. The shield ring 520 prevents an electrical coupling between the (powered) movable support ring 516 and the bottom ring 508. In this way, the voltage supplied to the movable upper ring 504 via the movable support ring 516 is maximized.

[0063] The bottom ring 508 includes an annular body 560 and a first protrusion 562 that extends radially inward from an intermediate portion of the radially inner surface of the bottom ring 508. A protrusion 564 extends radially inward from an upper portion of the radially inner surface of the bottom ring 508. In some examples, at least a portion of the protrusion 564 is disposed below the downward protrusion 546 of the movable upper ring 504. A protrusion 568 protrudes radially outward from the upper surface of the bottom ring 508. An outer ring 570 is disposed radially external to the bottom ring 508 and may be manufactured from a conductive material.

[0064] Referring to FIG. 2E, the inner sidewall 572 of the ring centering portion 542 is substantially vertical. For example, the portion between about 0.015 inches and 0.025 inches (0.38 millimeters and 0.6 millimeters) of the inner sidewall 572 is vertical. The vertical orientation of the sidewall 572 facilitates centering of the movable upper ring 504 relative to the support ring 516. Similarly, the annular recess 548 is defined by an outer sidewall 576 that is substantially vertical. The annular recess 548 defines a downward step that facilitates placement of the movable upper ring 504 below the cover ring 506.

[0065] In one embodiment, the overall outer diameter of the movable upper ring 504 is between about 12.8 inches and 13.2 inches (about 325 millimeters and 335 millimeters). The width of the annular body 540 is between about 0.5 inches and 0.6 inches (about 13 millimeters and 16 millimeters). For example, the width of the annular body 540 is configured to minimize the gap between the outer diameter of the movable upper ring 504 and the cover ring 506. Further, the width of the annular body 540 is configured to maximize the voltage potential of the movable upper ring 504 for a given amount of electrical power supplied from the movable support ring 516 to the movable upper ring 504. For example, as the width (e.g., overall volume) of the movable upper ring 504 increases, the amount of electrical power supplied will need to be increased. As an example, the width of the annular body is about 0.75 inches (about 19 millimeters) or less.

[0066] The width of the annular recess 548 is between about 0.12 inches and 0.16 inches (about 3 millimeters and 4 millimeters). For example, the width of the annular recess 548 is at least 20% of the width of the annular body 540. The depth of the annular recess is between about 0.035 inches and 0.045 inches (about 0.8 millimeters and 1.2 millimeters). For example, the depth of the annular recess 548 is at least 25% of the overall height of the movable upper ring 504. The overall height of the movable upper ring 504 is between about 0.125 inches and 0.140 inches (about 3.1 millimeters and 3.6 millimeters).

[0067] The width of the ring centering portion 542 is between about 0.4 inches and 0.5 inches (about 10 millimeters and 13 millimeters). For example, the width of the ring centering portion 542 is at least 75% of the width of the annular body 540. In one example, the width of the contact area (e.g., overlap) between the ring centering portion 542 and the upper surface of the movable support ring 516 is at least 0.2 inches (10 millimeters). As an example, the gap between the inner sidewall 572 of the ring centering portion 542 and the movable support ring is at least about 0.003 inches (about 0.076 millimeters). In some examples, the gap can be larger (e.g., between about 0.010 inches and 0.013 inches (about 0.25 millimeters and 0.33 millimeters)) to accommodate thermal expansion of the movable upper ring 504 during operation. In some examples, the upper surface of the movable support ring 516 occupies at least 97% of the ring centering portion 542.

[0068] The height or depth of the ring centering portion 542 (e.g., the cavity) is between about 0.040 inches and 0.050 inches (about 1.0 millimeter and 1.3 millimeters), which corresponds to the height of the downward protrusions 544 and 546. For example, the depth of the ring centering portion 542 is at least 28% of the overall height of the movable upper ring 504. The depth of the ring centering portion 542 is configured to provide sufficient vertical contact area between the sidewall of the ring centering portion 542 and the upper end of the movable support ring 516 to prevent lateral misalignment, such as when the movable upper ring 504 is installed on the movable support ring 516 and when the movable support ring 516 is used to raise and lower the movable upper ring 504.

[0069] The cover ring 506 is positioned above the bottom ring 508 and has an upper surface that is directly exposed to the plasma. In some examples, an annular recess 578 is defined in the upper surface of the bottom ring 508. In some examples, the cover ring 506 rests on the annular recess 578. The cover ring 506 includes an annular body 580 and a stepped portion 582. When installed, the stepped portion 582 extends upward radially inward and overlaps the annular recess 548 of the movable upper ring 504. The annular recess 548 increases the gap between the upper surface of the movable upper ring 504 and the lower surface of the stepped portion 582 to reduce the likelihood of arcing between the movable upper ring 504 and the cover ring 506 relative to the movable upper ring without the annular recess 548. In other words, without the annular recess 548, the upper surface of the movable upper ring 504 below the stepped portion 582 would be closer to the lower surface of the stepped portion 582, increasing the likelihood of arcing.

[0070] Furthermore, the stepped portion 582 extends across the gap between the outer diameter of the upper movable ring and the inner diameter of the cover ring 506 to interrupt the line of sight from the plasma environment to the structures below the movable upper ring 504 and the cover ring 506 (e.g., the bottom ring 508, the movable support ring 516, etc.).

[0071] As shown in FIG. 2A, in some assembly configurations, the cover ring 506 has a greater height relative to the movable upper ring 504 and extends above the bottom ring 508. Thus, the height or depth of the annular recess 584 defined below the stepped portion 582 is greater than the height of the movable upper ring 504. In other words, the height of the annular recess 584 from the bottom of the cover ring 506 to the bottom surface of the stepped portion 582 is greater than the height of the movable upper ring 504. As shown, the cover ring 506 extends from the bottom of the recess 578 to a height above the upper surface of the bottom ring 508. In other words, the height of the cover ring 506 is greater than the height of the recess 578. The cover ring 506 also extends to a height above the upper surface of the movable upper ring 504.

[0072] Dimensions such as the overall height of the movable upper ring 504, the depth of the annular recess 548, and the height of the annular recess 584 are configured to define a desired gap (i.e., in the vertical direction) between the upper surface of the annular recess 548 and the lower surface of the stepped portion 582. For example, the gap between the surface of the annular recess 548 and the lower surface of the stepped portion 582 is between about 0.08 inches and 0.12 inches (about 2.0 millimeters and 3.0 millimeters) when the movable support ring 516 is in its lowest position.

[0073] For example, in some embodiments, the movable upper ring 504 is powered to control process uniformity, which can cause greater erosion of the cover ring 506 (e.g., erosion of the inner diameter of the cover ring 506). For example, the voltage on the upper surface of the movable upper ring 504 below the stepped portion 582 increases the voltage on the surface of the cover ring 506, which increases the energy of the ions impinging on the cover ring 506.

[0074] Accordingly, since the height at the inner diameter of the covering 506 (and the thickness of the stepped portion 582) determines the usable life of the covering 506, the thickness or height of the covering 506 is at least about 0.245 inches (about 6.2 millimeters) in order to extend the usable life of the covering 506. Further, in this embodiment, the width of the covering 506 is selected to provide a gap between the outer diameter of the covering 506 and the bottom ring 508. In other words, when assembled for operation, the outer diameter of the covering 506 does not contact the bottom ring 508. Further, the outer diameter of the movable upper ring 504 does not directly adjoin any inner diameter of the bottom ring 508 and / or defines a gap from any inner diameter of the bottom ring 508. The gap prevents binding (e.g., vertical service) between the surfaces of adjacent moving ring structures and the surfaces of the fixed ring structures. In this context, the term fixed refers to a ring that generally does not move after installation without breaking the vacuum, and the term movable means that the position of the ring can be adjusted after installation by an actuator without breaking the vacuum, as described herein.

[0075] In one embodiment, the overall outer diameter of the covering 506 is between about 13.25 inches and 13.5 inches (about 336 millimeters and 343 millimeters). The width of the annular body 580 of the covering 506 is between about 0.34 inches and 0.39 inches (about 8.6 millimeters and 9.9 millimeters). The overall height of the covering 506 is between about 0.245 inches and 0.260 inches (about 6.2 millimeters and 6.6 millimeters). The height of the annular recess 584 is between about 0.185 inches and 0.195 inches (about 4.6 millimeters and 5.0 millimeters). For example, the height of the annular recess 584 is at least 60% of the overall height of the covering 506. In one embodiment, the height of the annular recess 584 is at least 75% of the overall height of the covering 506. The width of the annular recess 584 is between about 0.10 inches and 0.15 inches (about 2.5 millimeters and 3.8 millimeters). For example, the width of the annular recess 584 is at least 32% of the overall width of the annular body 580. Thus, the width of the annular recess 584 is configured to accommodate the entirety of the portion of the movable upper ring 504 that corresponds to the annular recess 548. Further, the outer diameter of the movable upper ring 504 does not contact the inner diameter of the covering 506 while the movable upper ring 504 is in its lowest position, while raising and lowering the movable upper ring 504, etc.

[0076] Accordingly, the annular recess 578 of the bottom ring 508 is configured to accommodate a cover ring 506 having a height or thickness of at least about 0.20 inches (about 5.0 millimeters). Further, when assembled for operation, the outer diameter of the movable upper ring 504 does not contact the inner diameter of the cover ring 506, and the bottom surface of the movable upper ring 504 does not contact (i.e., is not supported on) the upper surface of the protrusion 564 of the bottom ring 508. In this way, the movable upper ring 504, the cover ring 506, and the bottom ring 508 can be manufactured with more stringent tolerances since the outer diameter of the movable upper ring 504 is only proximate to the inner diameter of the cover ring 506. Generally, manufacturing tolerances must be selected such that a sufficient gap is ensured between components to prevent binding or contact between components and to ensure that the components will fit properly together. Thus, looser manufacturing tolerances can result in larger gaps. The configuration described above allows for more stringent manufacturing tolerances, which refers to a smaller maximum gap between components. In other words, the possibility of contact between the outer diameter of the movable upper ring 504 and the inner diameter of the cover ring 506 or any part of the bottom ring 508 is eliminated, yet still the width of the gap is minimized.

[0077] In one embodiment, the overall outer diameter of the bottom ring 508 is between about 14.60 inches and 14.80 inches (about 370 millimeters and 376 millimeters). The overall height of the bottom ring 508 is between about 2.85 inches and 2.95 inches (about 72 millimeters and 75 millimeters). The width of the annular recess 578 is between about 0.25 inches and 0.35 inches (about 6.3 millimeters and 8.9 millimeters). The height of the annular recess 578 is between about 0.20 inches and 0.30 inches (about 5.0 millimeters and 7.6 millimeters). As described above, the annular recess 578 of the bottom ring 508 is configured to accommodate a cover ring 506 having a height or thickness of at least about 0.20 inches (about 5.0 millimeters). Further, the width of the annular recess 578 is configured to accommodate and support the entire width of the lower surface of the cover ring. In other words, the cover ring 506 is disposed between the outer diameter of the movable upper ring that forms part of the annular recess 578 and the inner diameter of the bottom ring 508. Further, the protrusion 564 that defines the lower surface of the annular recess 578 extends above the shield ring 520 to protect the shield ring 520, and the protrusion 568 extends above the outer ring 570 to protect the outer ring 570.

[0078] In an embodiment, when the movable support ring 516 is in its lowest position, the movable upper ring 504 rests on top of the movable support ring 516 (as shown in FIG. 2A) and contacts only the movable support ring 516. In other words, in its lowest position, the movable upper ring 504 does not contact any portion of the inner ring 512, the cover ring 506, or the bottom ring 508. Thus, there is no risk of binding between the movable upper ring 504 and fixed components such as the cover ring 506, the bottom ring 508, and the inner ring 512 during movement of the movable upper ring 504. Further, since the movable upper ring 504 is powered, the absence of contact between the movable upper ring 504 and other components reduces the risk of electrical communication between the movable upper ring 504 and other components.

[0079] In some embodiments, the inner ring 512 has a generally "L" - shaped cross - section that defines an outer annular recess 586. The outer annular recess 586 is configured to receive the downward protrusion 544 of the movable upper ring 504. The overall outer diameter of the inner ring 512 is between about 11.95 inches and 12.05 inches (about 303 millimeters and 306 millimeters). The inner diameter of the inner ring 512 is between about 11.55 inches and 11.75 inches (about 293 millimeters and 299 millimeters). The overall height of the inner ring 512 is between about 0.175 inches and 0.195 inches (about 4.4 millimeters and 5.0 millimeters). The height of the annular recess 586 is between about 0.10 inches and 0.12 inches (about 2.54 millimeters and 3.048 millimeters). The width of the annular recess 586 is between about 0.080 inches and 0.095 inches (about 2.0 millimeters and 2.4 millimeters).

[0080] Next, referring to FIG. 3A, another example of an edge - ring system 600 includes, among other components, a movable upper ring 604, a cover ring 606, a bottom ring 608, and an inner ring 612. In one embodiment, the movable upper ring 604 is composed of silicon carbide, and the cover ring 606, the bottom ring 608, and the inner ring 612 are composed of quartz.

[0081] FIG. 3B is a top isometric view of the movable upper ring 604. FIG. 3C is a bottom isometric view of the movable upper ring 604. FIG. 3D is a side cross - sectional view of the entire movable upper ring 604. FIG. 3E is a side cross - sectional view of a portion of the body 680 of the movable upper ring 604. FIG. 3F is a bottom isometric view of the cover ring 606. FIG. 3G is a side cross - sectional view of the entire cover ring 606. FIG. 3H is a side cross - sectional view of a portion of the body 680 of the cover ring 606.

[0082] In edge ring system 600, bottom ring 608 and inner ring 612 are substantially the same as bottom ring 508 and inner ring 512 described above. For example, bottom ring 608 includes an annular body 660. A first protrusion 662 extends radially inward from an intermediate portion of the radially inner surface of bottom ring 608. A protrusion 664 extends radially inward from an upper portion of the radially inner surface of bottom ring 608. A protrusion 668 projects radially outward from the upper surface of bottom ring 608.

[0083] In one embodiment, inner ring 612 has a generally "L" - shaped cross - section that defines an outer annular recess 614. Outer annular recess 614 is configured to receive a downward protrusion 644 of movable upper ring 604. In one embodiment, the overall outer diameter of bottom ring 608 is between about 14.60 inches and 14.80 inches (about 370 millimeters and 376 millimeters). The overall height of bottom ring 608 is between about 2.85 inches and 2.95 inches (about 72 millimeters and 75 millimeters). The width of annular recess 678 is between about 0.25 inches and 0.35 inches (about 6.3 millimeters and 8.9 millimeters). The height of annular recess 678 is between about 0.20 inches and 0.30 inches (about 5.0 millimeters and 7.6 millimeters). For example, the height of annular recess 678 is at least 6% of the overall height of bottom ring 608.

[0084] The ring centering portion 642 of the movable upper ring 604 is defined between the downward protrusion 644 and the downward protrusion 646. In some embodiments, the inner sidewall 616 of the ring centering portion 642 is substantially vertical. The vertical orientation of the sidewall 616 facilitates the centering of the movable upper ring 604 with respect to the support ring 516. As shown in FIG. 3E, the outer radius 620 of the movable upper ring 604 is curved. The curved outer radius 620 reduces the electric field concentration associated with sharper corners, thereby reducing the likelihood of arcing between the surface of the movable upper ring 604 and the surface of the cover ring 606. Arcing increases the erosion of the surfaces exposed to the plasma and reduces the lifespan of components such as the movable upper ring 604 and the cover ring 606.

[0085] In one embodiment, the overall outer diameter of the movable upper ring 604 is between about 12.8 inches and 13.2 inches (about 325 millimeters and 335 millimeters). The width of the annular body 640 of the movable upper ring 604 is between about 0.5 inches and 0.6 inches (about 13 millimeters and 16 millimeters). The overall height of the movable upper ring 604 is between about 0.135 inches and 0.150 inches (about 3.4 millimeters and 3.8 millimeters). The width of the ring centering portion 642 is between about 0.4 inches and 0.5 inches (about 10 millimeters and 13 millimeters). For example, the width of the ring centering portion 642 is at least 75% of the width of the annular body 640. The height or depth of the ring centering portion 642 is between about 0.040 inches and 0.050 inches (about 1.0 millimeter and 1.3 millimeters). For example, the depth of the ring centering portion 642 is at least 26% of the overall height of the movable upper ring 604.

[0086] The radius of curvature of the outer radius 620 is between approximately 0.070 inches and 0.090 inches (about 1.7 millimeters and 2.3 millimeters). The radius of curvature is configured to reduce the electric field concentration associated with sharper corners, such as the corner at the right angled or chamfered transition from the upper surface of the movable upper ring 604 to the side wall. Thus, the greater the radius of curvature, the greater the reduction in electric field concentration. However, if the radius of curvature is too large, the vertical gap / interface between the outer diameter of the movable upper ring 604 and the inner diameter of the cover ring 606 will be significantly reduced or eliminated, which allows a direct line of sight to the structure below the movable upper ring 604 and the cover ring 606. Thus, the radius of curvature described above is configured such that the vertical portion of the outer diameter of the movable upper ring 604 is between approximately 0.040 inches and 0.075 inches (about 1.0 millimeter and 1.9 millimeters).

[0087] In FIG. 3A, the inner radius 624 of the cover ring 606 is curved in a manner similar to the outer radius 620 to reduce the electric field concentration. Further, the cover ring 606 has a greater height relative to the movable upper ring 604 and extends above the bottom ring 608. Thus, the height or depth of the annular recess 628 defined below the stepped portion 682 is greater than the height of the movable upper ring 604. In other words, the height of the annular recess 628 from the bottom of the cover ring 606 to the bottom surface of the stepped portion 682 is greater than the height of the movable upper ring 604. As shown, the cover ring 606 extends from the bottom of the recess 678 and the bottom of the movable upper ring 604 to a height above the upper surface of the bottom ring 608. In other words, the height of the cover ring 606 is greater than the height of the recess 678 to extend the useful life of the cover ring 606. The cover ring 606 also extends to a height above the upper surface of the movable upper ring 604.

[0088] In one embodiment, the overall outer diameter of the covering 606 is between about 13.25 inches and 13.5 inches (about 336 millimeters and 343 millimeters). The width of the annular body 680 of the covering 606 is between about 0.33 inches and 0.37 inches (about 8.3 millimeters and 9.4 millimeters). The overall height of the covering 606 is between about 0.345 inches and 0.360 inches (about 8.7 millimeters and 9.2 millimeters). The height of the annular recess 628 is between about 0.230 inches and 0.250 inches (about 5.8 millimeters and 6.4 millimeters). For example, the height of the annular recess 628 is at least 63% of the overall height of the covering 606. The width of the annular recess 628 is between about 0.10 inches and 0.15 inches (about 2.5 millimeters and 3.8 millimeters). For example, the width of the annular recess 628 is at least 32% of the width of the annular body 680. The radius of curvature of the inner radius 624 is between about 0.070 inches and 0.090 inches (about 1.7 millimeters and 2.3 millimeters).

[0089] In previous embodiments, some of the edge rings are made of a conductive material or a conductive or non - conductive material with a conductive coating. As used herein, conductive refers to a material or coating having a resistivity less than or equal to 10 4 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 approximately 10 -7 Ωcm. In some examples, the edge rings of the present disclosure are made of a non - conductive material or a conductive or non - conductive material with a non - conductive coating. As used herein, non - conductive refers to a material / coating having a resistivity greater than 10 4 Ωcm.

[0090] The conductive ring can be manufactured from one or more base materials, one or more plating layers, and / or one or more coatings. Non-limiting examples of base materials include silicon, silicon carbide, titanium, graphite, quartz, and / or ceramic. Non-limiting examples of plating layers include aluminum plating. Non-limiting examples of coatings include perfluoroalkoxy (PFA), atomic layer deposition (ALD) aluminum oxide (Al2O3), ALD yttrium oxide or yttria (Y2O3), and / or an anodized coating. For example, the conductive material can include anodized titanium, silicon with a PFA coating, doped silicon, silicon with aluminum plating and an anodized coating, silicon with ALD aluminum oxide, silicon with an ALD yttria coating, silicon carbide, graphite with a PFA coating, graphite with aluminum plating and an anodized coating, graphite with an ALD aluminum oxide coating, graphite with an ALD yttria coating, or other suitable materials. Non-limiting examples of non-conductive materials include quartz and ceramic. In previous embodiments, one or more of the rings can be formed by one or more structures in the radial direction, axial direction, or other direction.

[0091] The foregoing description is merely illustrative in nature and is in no way limiting of the disclosure, its applications, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Accordingly, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in a different order (or concurrently) without altering the principles of the disclosure. Further, although each of the embodiments has been described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and / or combined with any of the features of any of the other embodiments, whether or not such combination is explicitly described, and this is done even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substituting one or more of the embodiments for each other remains within the scope of the disclosure.

[0092] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms including "connected", "engaged", "coupled", "adjacent", "next to", "on top of", "above", "below", and "disposed". Unless explicitly described as being "direct", when the relationship between a first element and a second element is described in the above disclosure, the relationship can be a direct relationship where no other intervening element exists between the first element and the second element, but can also be an indirect relationship where one or more intervening elements exist (either spatially or functionally) between the first element and the second element. As used herein, the phrase "at least one of A, B, and C" should be construed to mean a logical (A OR B OR C) using non-exclusive logical OR and should not be construed to mean "at least one of A, at least one of B, and at least one of C". The term "about" as used herein means + / - 10% of a given value and / or + / - 5% of a given ratio.

[0093] In some implementations, the controller can be part of a system, which can be part of the examples described above. Such a system can comprise semiconductor processing equipment including one or more processing tools for processing, one or more chambers, one or more platforms, and / or certain processing components (such as wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronics for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. The electronics may be referred to as a “controller,” which can control various components or sub-parts of one or more systems. The controller can be programmed to control any of the processes disclosed herein, depending on the processing requirements and / or the type of system, including delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer transfer including tools connected to or interfaced with a particular system and other transfer tools and / or entering and exiting a load lock.

[0094] Generally, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuit can include firmware storing program instructions, a digital signal processor (DSP), a chip defined as an application-specific integrated circuit (ASIC), and / or one or more microprocessors or chips in the form of a microcontroller that execute program instructions (e.g., software). The program instructions can be instructions communicated to the controller in the form of various individual settings (or program files) that define operating parameters for performing specific processes on or for a semiconductor wafer or system. The operating parameters can, in some embodiments, be part of a recipe defined by a process engineer to achieve one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of the wafer.

[0095] In some implementations, the controller can be part of a computer that is integrated with, coupled to, or networked to the system, or coupled to that computer, or a combination thereof. For example, the controller can be in the "cloud" or in all or part of a fab host computer system that enables remote access to wafer processing. The computer can monitor the current progress of the fabrication operation, examine the history of past fabrication operations, and examine trends or performance metrics from multiple fabrication operations to change the parameters of the current process, set the process steps to follow the current process, or initiate a new process, and can enable remote access to the system. In some examples, a remote computer (e.g., a server) can provide a process recipe to the system over a network that can include a local network or the Internet. The remote computer can include a user interface that enables entry or programming of parameters and / or settings, and the parameters and / or settings are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each of the process steps to be performed during one or more operations. It should be understood that the parameters can be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller can be distributed, such as by comprising one or more individual controllers that are networked together and function towards a common purpose such as the processes and controls described herein. An example of a distributed controller for such a purpose would be one or more integrated circuits on a chamber that communicate with one or more integrated circuits remote (such as at the platform level or as part of a remote computer) that are combined to control the process on the chamber.

[0096] While not limiting, exemplary systems can include a plasma etching chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etching chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etching (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that can be associated with or used in the fabrication and / or manufacture of semiconductor wafers.

[0097] As described above, depending on one or more process steps to be performed by a tool, the controller can communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a main computer, another controller, or tools used in wafer container transport in material handling between tool locations and / or load ports in a semiconductor manufacturing facility.

Claims

1. A covering for an edge ring system, wherein the covering is configured to be disposed above and radially outward of a movable upper ring of the edge ring system, the covering comprising: an annular body; a stepped portion extending radially inward from the annular body, the stepped portion being configured to extend above an outer edge of the movable upper ring of the edge ring system; an annular recess defined at an inner radius of the covering below the stepped portion, the annular recess being configured to receive the outer edge of the movable upper ring, the height of the annular recess being at least 60% of the overall height of the covering; A covering comprising the above components.

2. The covering according to claim 1, wherein the covering is composed of a non-conductive material.

3. The covering according to claim 1, wherein the height of the annular recess is at least 75% of the overall height of the covering.

4. The covering according to claim 1, wherein the width of the annular recess is at least 32% of the width of the annular body.

5. The covering according to claim 1, wherein the inner radius of the covering is curved.

6. The covering according to claim 5, wherein the inner radius has a radius of curvature between 0.070 inches and 0.090 inches.

7. The covering according to claim 5, wherein the height of the annular recess is at least 63% of the overall height of the covering.

8. The covering according to claim 5, wherein the width of the annular recess is at least 32% of the width of the annular body.

9. A movable upper ring for an edge ring system, the movable upper ring comprising: an annular body; an outer radius of the annular body, the outer radius being curved. A ring centering portion formed in the lower surface of the annular body and configured to center the movable upper ring on the movable support ring, wherein the lower surface includes downward projections disposed at a radially inner location and a radially outer location of the annular body to define the ring centering portion. A movable upper ring comprising the above.

10. The movable upper ring according to claim 9, wherein the ring centering portion forms a cavity in the lower surface of the annular body, and the downward projections are disposed on both sides of the cavity.

11. The movable upper ring according to claim 9, wherein the inner side wall of the ring centering portion is substantially vertical.

12. The movable upper ring according to claim 9, wherein the outer radius has a radius of curvature between 0.070 inches and 0.090 inches.

13. The movable upper ring according to claim 9, wherein the width of the ring centering portion is at least 75% of the width of the annular body.

14. The movable upper ring according to claim 9, wherein the depth of the ring centering portion is at least 26% of the overall height of the movable upper ring.

15. A bottom ring for an edge ring system, the bottom ring being configured to support a cover ring of the edge ring system, the bottom ring comprising: An annular body; A first projection extending radially inward from an upper portion of the radially inner surface of the annular body; An annular recess defined in the radially inner surface of the annular body above the projection, the annular recess being configured to support the cover ring; A second projection extending radially outward from an upper portion of the radially outer surface of the annular body; A bottom ring comprising the above.

16. The bottom ring according to claim 15, wherein the height of the annular recess is at least 6% of the overall height of the bottom ring.

17. A bottom ring, wherein the bottom ring comprises: (i) an annular body; (ii) a protrusion extending radially inwards from an upper portion of the radially inner surface of the annular body of the bottom ring; and (iii) an annular recess defined in the radially inner surface of the annular body above the protrusion. A cover ring disposed above and radially inwards of the bottom ring and supported on the protrusion within the annular recess of the bottom ring, wherein the cover ring comprises: (i) an annular body; (ii) a stepped portion extending radially inwards from the annular body of the cover ring; and (iii) an annular recess defined at an inner radius of the cover ring below the stepped portion. A movable upper ring disposed below and radially inwards of the cover ring, wherein the movable upper ring comprises: (i) an annular body, wherein an outer radial portion of the annular body of the movable upper ring extends below the cover ring and reaches the annular recess of the cover ring; and (iii) a ring centering portion formed in a lower surface of the annular body of the movable upper ring. An edge ring system comprising the above.

18. The movable upper ring according to claim 17, wherein an inner side wall of the ring centering portion is substantially vertical.

19. The edge ring system according to claim 18, wherein the movable upper ring An annular recess disposed on an upper and outer radial portion of the annular body, the annular recess being defined by an outer side wall and a downward step, and the outer side wall being substantially vertical. Downward protrusions disposed at a radially inner location and a radially outer location of the lower surface to define the ring centering portion. The edge ring system further comprising the above.

20. The edge ring system according to claim 17, wherein the movable upper ring has a curved outer radius.

21. The edge ring system according to claim 20, wherein the outer radius has a radius of curvature between 0.070 inches and 0.090 inches.

22. The edge ring system according to claim 17, wherein the annular recess of the covering is configured to receive the outer edge of the movable upper ring, and the height of the annular recess of the covering is at least 70% of the overall height of the covering.

23. The edge ring system according to claim 17, wherein the inner radius of the covering is curved.

24. The edge ring system according to claim 23, wherein the inner radius has a radius of curvature between 0.070 inches and 0.090 inches.

25. The edge ring system according to claim 17, further comprising an inner ring disposed below and radially inward of the movable upper ring, the inner ring having an "L"-shaped cross-section defining an outer annular recess.

26. The edge ring system according to claim 25, wherein the outer annular recess is arranged to receive the radially inner edge of the movable upper ring.

27. The edge ring system according to claim 26, wherein the outer diameter of the covering does not contact the bottom ring.

28. The edge ring system according to claim 26, wherein the outer diameter of the movable upper ring does not contact the bottom ring.

29. The edge ring system according to claim 26, wherein when in the lowest position, the movable upper ring does not contact any part of the inner ring, the covering, or the bottom ring.

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