Plasma radical edge ring barrier seal

Abstract

The barrier seal ring for the plasma chamber includes an outer seal leg extending vertically downward from the top to the bottom along the outer diameter, and an inner seal leg extending downward from the top to the inner diameter. The upper portion of the inner seal leg extends at an angle to the outer seal leg, and the lower portion extends downward from the bottom of the upper leg, establishing an interface between the upper and lower leg portions. This interface allows the inner seal leg to bend inward toward the inner surface of the outer seal leg during installation into the groove of the base ring located at the lower electrode of the plasma chamber.

Description

Technical Field

[0001] The present disclosure relates to providing a seal ring within a semiconductor process module.

Background Art

[0002] In semiconductor processing, wafers are subjected to various operations to form features that define integrated circuits. For example, in a plasma etching operation, a wafer is housed within a plasma chamber and exposed to plasma generated within a plasma processing region defined within the plasma chamber. The plasma interacts with the material on the surface of the wafer, removing or modifying the material and ultimately removing it from the surface. Depending on the type of feature to be formed, a specific type of reactive gas is supplied to the chamber, and a radio frequency (RF) signal from an RF power source is applied to activate the specific reactive gas to generate plasma. The RF signal is supplied via the plasma processing region containing the reactive gas.

[0003] The plasma is controlled within the plasma processing region such that the radicals of the plasma are limited to the area above the wafer, causing an optimal plasma etching operation. The edge ring is defined to surround a wafer support (e.g., an electrostatic chuck) defined within the lower electrode. Due to being constantly exposed to highly reactive plasma radicals, the edge ring is eroded, and the service life of the edge ring is limited. When the surface of the edge ring is eroded, other components below the edge ring (such as a thermal gasket on which the edge ring is supported on the lower electrode) are exposed to the highly reactive radicals of the plasma that also damage these components. The edge ring needs to be replaced when it reaches its lifespan. Along with the edge ring, the thermal gasket also needs to be replaced.

[0004] The RF signal transmission path affects how the plasma is generated and how the plasma sheath is managed. For example, the reactive gas may be activated more extensively in certain areas of the plasma processing region where a larger amount of RF signal power is transmitted, leading to spatial non-uniformity of the plasma properties across the entire plasma processing region. Plasma properties that cause spatial non-uniformity include non-uniformity in ion density, ion energy, and reactive gas density. Spatial non-uniformity in plasma properties can lead to non-uniformity in the plasma processing results on the wafer.

[0005] To address spatial inhomogeneities and control the plasma sheath profile, an adjustable edge sheath (TES) assembly is defined, which independently powers the edge electrodes. The edge electrodes are separated from the main electrodes, which are used to transmit RF signals to power the reaction gas received in the plasma processing area. The TES assembly includes multiple quartz components / elements, ceramic supports, and edge electrodes connected to an RF power supply, providing RF power to the plasma processing area via an edge ring. With the introduction of the TES assembly, additional components (e.g., plastic components) susceptible to attack by plasma radicals have also been introduced. Erosion of these TES assembly components by radical attack becomes a limiting factor affecting the mean time between cleanings and adds costly consumables.

[0006] The implementation of the present invention arises from this background. [Overview of the project]

[0007] In the various implementations discussed herein, a barrier seal ring is introduced into an adjustable edge sheath (TES) assembly located at the bottom of the plasma process chamber (or simply referred to as the "plasma chamber"). The bottom of the plasma chamber, in some implementations, includes a lower electrode powered by a radio frequency (RF) power supply, and the TES assembly is located below the edge ring surrounding a wafer support surface (e.g., an electrostatic chuck (ESC)) located within the lower electrode. The TES assembly is introduced into the plasma chamber to better control the profile of the plasma sheath covering the wafer edge. The TES assembly is provided to independently power the edge electrode (different from the main electrode that powers the ESC (i.e., the lower electrode) within the plasma chamber) located below the edge ring. The barrier seal ring is incorporated into the TES assembly and used to seal gaps between certain components of the TES assembly to effectively prevent plasma radicals from reaching other underlying components of the TES assembly (e.g., plastic components). The barrier seal ring is made of a low-corrosion material. Blocking the path to parts in the TES assembly results in improved service life for additional parts, reduced consumable costs, and improved average time between cleanings of parts in the TES assembly.

[0008] Typically, edge rings are designed to include gaps between the edge ring and the various components adjacent to it. These gaps are introduced to accommodate thermal expansion and / or mechanical tolerances. The downside of having gaps between the edge ring and the various components adjacent to it is that the gaps allow plasma radicals to follow the least-resistance path and attack the material located below the edge ring in the plasma chamber. Before the introduction of TES assemblies into the plasma chamber, the gaps between the various components of the edge ring assembly did not affect the integrity of the various components of the plasma chamber below the edge ring because the various components of the lower electrode were less susceptible to attack from plasma radicals. However, with the introduction of TES assemblies, insulating components such as plastic parts were introduced to surround the conductive rods that supply power to the edge electrodes. The gaps between the edge ring and the adjacent components allowed plasma radicals to flow through the gaps and attack the vulnerable plastic parts, resulting in a decrease in the mechanical strength of the parts and visible erosion of the enclosed parts (e.g., conductive rods).

[0009] To prevent attacks on vulnerable insulating components (e.g., plastic components), a barrier seal ring was introduced above the plastic components of the TES assembly to block the flow of plasma radicals toward the plastic components. The barrier seal ring is incorporated into a groove defined within the base ring of the TES assembly, located below the edge ring. The base ring is made of quartz. The barrier seal ring is made from a material resistant to plasma radicals and is flexible enough to be easily pressed into the groove defined within the base ring. The base ring is positioned adjacent to and surrounding the TES ring and a portion of the ceramic support elements located below the TES ring. The insulating material of the TES assembly (e.g., plastic or ceramic components) is embedded in the ceramic support elements defined below the TES ring, surrounding the ESC. The barrier seal ring is used to seal the gap between the TES ring and the base ring. By effectively sealing the gap, the barrier seal ring prevents plasma radicals from reaching the insulating material embedded in the ceramic support elements of the TES assembly, preserving the integrity of the insulating material and the conductive rods encapsulated within it. By preventing the erosion of insulating materials, barrier seal rings allow for the reuse of insulating materials such as plastic parts for multiple wet cleanings, thereby improving the average time between cleanings and reducing the cost of consumables.

[0010] In one implementation, a barrier seal ring for a plasma chamber is disclosed. The barrier seal ring includes an outer seal leg extending vertically downward along its outer diameter. The outer seal leg includes an upper chamfer and a lower chamfer defined along the outer diameter of the barrier seal ring. An inner seal leg is connected to the upper part of the outer seal leg. The inner seal leg is oriented at an angle to the outer seal leg. The inner seal leg includes an upper leg portion and a lower leg portion. The lower leg portion of the inner seal leg forms an initial gap of a first distance with respect to the outer seal leg. The lower leg portion is configured to flex toward the outer seal leg and to form a second gap that is smaller than the first distance of the initial gap but greater than zero. The barrier seal ring is set in a groove of the first ring and is configured to seal when the inner seal leg is pressed against the second ring. The first and second rings are part of the plasma chamber. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a simplified block diagram of the lower part of a plasma chamber in which a barrier seal ring is employed within an adjustable edge sheath assembly, in one implementation configuration.

[0012] [Figure 2] Figure 2 is a side perspective view of a base ring having a groove for accommodating the barrier seal ring shown in Figure 1.

[0013] [Figure 3] Figure 3 is an enlarged cross-sectional view of the barrier seal ring shown in Figure 2.

[0014] [Figure 4] Figure 4 is an enlarged cross-sectional view of the barrier seal ring shown in Figure 3, with some dimensions specified.

[0015] [Figure 5] Figure 5 is a magnified cross-sectional view of the barrier seal ring in Figure 3, showing the identified positional profile.

[0016] [Figure 6] Figure 6 is a top perspective view of the barrier seal ring of FIG. 3.

[0017] [Figure 7] Figure 7 is a side view of the barrier seal ring of FIG. 3.

[0018] [Figure 8] Figure 8 is a top view of the barrier seal ring of FIG. 3.

[0019] [Figure 9] Figure 9 is a bottom view of the barrier seal ring of FIG. 3.

[0020] [Figure 10A] Figure 10A is a side view of FIG. 7 and is used to provide an enlarged cross-sectional view of the barrier seal ring of FIG. 7.

[0021] [Figure 10B] Figure 10B is an enlarged cross-sectional view of the barrier seal ring of FIG. 10A.

Embodiments for Carrying Out the Invention

[0022] This document describes in detail the features of various components of a barrier seal ring used within a plasma process module (or, as referred to herein, the “process module”) to block the flow of plasma radicals toward various underlying components of the plasma chamber defined within the process module, and to prevent attacks on these components. The barrier seal ring is incorporated into a first ring adjacent to and surrounding a second ring defined at the bottom of the process module. In one configuration, the first ring is a base ring located below the first portion of an edge ring surrounding a substrate support surface defined at the bottom of the process module, and the second ring is an adjustable edge sheath (TES) ring of a TES assembly defined below the second portion of the edge ring. The barrier seal ring is used to effectively block the path between the first and second rings, which is used by plasma radicals to attack various underlying components, such as insulating (plastic, etc.) components of the TES assembly. A groove is defined along the inner sidewall of the base ring. The groove is formed to a size that accommodates the barrier seal ring. The barrier seal ring is made of a flexible material that is resistant to erosion by fluorine and / or other components of plasma radicals. Chamfered edges are provided on various outer corners (both top and bottom) of the barrier seal ring, ensuring that the barrier seal ring is pressed into place within the groove, and that it is properly seated and fully engages with the inner sidewalls of the groove defined within the base ring. The size and flexibility of the barrier seal ring ensure that it is fully housed and held in place within the groove without causing interference with the lower outer corner of the groove or interference between parts of the barrier seal ring. Furthermore, the size, shape, and design of the barrier seal ring are determined to seal the path between the base ring and adjacent parts below the process module so that plasma radicals cannot attack the underlying components.

[0023] Broadly speaking, the plasma chamber includes an upper member (also rephrased as the “upper”), a lower member (also rephrased as the “lower”), and a side wall extending between the upper and lower members, defining a plasma processing area within it. The upper member is configured to be connected to a gas source for supplying reaction gas to the plasma processing area. The lower member includes at least an electrostatic chuck (ESC) connected to a radio frequency (RF) power supply, which powers the reaction gas through the ESC to generate plasma in the plasma processing area. The RF power supply powering the reaction gas through the ESC represents the main power supply, with the ESC functioning as the main electrode. In addition to the main power supply, the lower member also includes a second RF power supply used to provide RF power for controlling the plasma sheath profile above an edge ring positioned to surround the ESC. The second power supply is connected to an edge electrode embedded in an adjustable edge sheath (TES) ring of a TES assembly included in the lower member. TES assemblies are used to control the properties of the plasma sheath near the periphery of a wafer, which is housed on an ESC and covering the edge ring. Controllable properties include plasma density, ion attraction, or bounce. By controlling the properties of the plasma, TES assemblies enable the tuning of the plasma sheath at the wafer edge (i.e., influencing the plasma sheath profile), improving radial uniformity across the entire wafer surface. Improved radial uniformity results in increased yield and improved quality of devices formed on the wafer.

[0024] By introducing the TES assembly to the lower member, however, plasma-sensitive elements (such as plastic components) are also introduced, which are used to surround certain parts of the TES assembly (e.g., conductive rods connected to the second RF power supply). For example, the plastic component with the conductive rod is embedded in a ceramic support element located below the TES ring. The plastic component acts as an insulator surrounding the conductive rod. The conductive rod is connected to the RF power supply at its first end, extends through the plastic component, and connects at its second end to an edge electrode embedded in the TES ring. The TES ring is defined below a portion of the edge ring surrounding the ESC. Since various wafers are processed using the plasma generated in the plasma processing area, the edge ring adjacent to the wafer-receiving ESC is constantly exposed to plasma radicals. This constant exposure causes erosion of the edge ring's surface. As the edge ring's surface is eroded, the gap between the edge ring and adjacent components such as the covering ring and TES ring (i.e., the connecting ring) begins to widen, and plasma radicals begin to find a path through the gap to the lower components of the TES assembly. The gap between the edge ring and the adjacent part is provided taking into account thermal expansion tolerances or mechanical tolerances. To prevent radical erosion of the lower part of the TES assembly (especially the vulnerable plastic part), improve the mean time between cleanups (MTBC), and reduce the cost of consumables (CoC), a barrier seal ring is introduced in the path above the plastic part to block the flow of plasma radicals toward the plastic part of the TES assembly, preventing the plasma radicals from attacking the plastic part. The barrier seal ring is housed in a groove defined within the inner sidewall of the base ring (e.g., the first ring) that surrounds the TES ring adjacent to the TES ring (e.g., the second ring).

[0025] The various parts (i.e., components) used to surround the ESC are selected to close all high-voltage pathways between the ESC and the grounding ring. To avoid the risk of arc discharge and to close the high-voltage pathways, the various parts are arranged to be in physical contact with each other. For example, the edge ring was connected to the ESC using a thermal gasket. Alternatively, the edge ring was connected directly using an O-ring. A base ring was positioned below a portion of the edge ring. Both the rest of the edge ring and the base ring rested on a ceramic support (i.e., an insulating ring) surrounding the ESC. This stacking of components leaves gaps, particularly between the bottom of the edge ring and the base ring. A challenge in edge ring design is the lack of a way to close these gaps without flexible components. Thermal gaskets and other means of connecting the edge ring did not provide the necessary flexibility and chemical / mechanical strength because they were as susceptible to plasma radicals as the edge ring itself.

[0026] The barrier seal ring is designed to provide the necessary flexibility and chemical / mechanical strength, ensuring that the pathway is completely sealed to maintain the integrity of the plastic component and other underlying components. The barrier seal ring includes an outer seal leg extending to an outer diameter equal to the outer diameter of a groove defined within the base ring in which the barrier seal ring is housed, and an inner seal leg extending to an inner diameter equal to the inner diameter of the groove. The width of the barrier seal ring is determined to ensure that the outer diameter of the barrier seal ring is always in contact with the inner diameter of the groove in the base ring, and that the inner diameter of the barrier seal ring is in contact with the outer diameter of the adjacent TES ring. The outer diameter of the barrier seal ring is determined to ensure that the outer diameter of the barrier seal ring is compressed within the base ring during installation, ensuring that the seal is centered and in contact with the inner diameter of the groove in the base ring. The inner diameter of the barrier seal ring is determined to ensure a secure interlock with the outer diameter of the TES ring and is designed to flex to ensure that contact is always reliably maintained. The material used to define the barrier seal ring is selected to be resistant to the effects of plasma radicals, allowing the barrier seal ring to be reused. The height of the outer seal legs in the outer diameter is determined to ensure that, at the operating temperature of the plasma chamber, the barrier seal ring does not excessively exceed the height of the groove in the base ring into which it is seated. The heights of the outer and inner seal legs of the barrier seal ring, as well as the groove size, are designed to ensure that the inner seal legs fold into the groove when the barrier seal ring flexes inward. Chamfers are provided on each outer corner of the barrier seal ring to ensure that the barrier seal ring is securely housed within the groove of the base ring without interference between the base ring surface defining the groove or between the inner seal legs. It should be noted that the use of barrier seal rings in TES assemblies is for protecting underlying components from plasma attacks, and this is one application of the barrier seal ring.The concept of a barrier seal ring can be extended to use in fixed locations within a plasma chamber, other than the TES assembly, to prevent the flow of plasma or other gases, or other gaseous by-products, from entering areas where such flow should not be accepted, and to effectively seal other areas.

[0027] Figure 1 is a vertical cross-sectional view of the lower part (i.e., lower member 102) of the plasma process chamber (or, hereafter simply referred to as the "plasma chamber") of a process module 100 used in wafer processing, in a certain implementation configuration. The plasma chamber of the process module 100 is designed to include a barrier seal ring 125 within the TES assembly defined in the plasma chamber to prevent plasma radicals from reaching the lower components of the TES assembly. The plasma chamber in the process module 100 includes an electrode 109, which in some implementation configurations is formed of a conductive element such as aluminum. A ceramic layer 110 is formed on the upper surface of the electrode 109. The ceramic layer 110 is configured to receive and support the wafer W when a plasma processing operation is performed on the wafer W. In some implementation configurations, the ceramic layer 110, the electrode 109, and related components define an electrostatic chuck (ESC).

[0028] Power is supplied to the ESC from a radio frequency (RF) power supply. In one implementation configuration, the RF power supply includes one or more RF signal generators that provide power through matching circuits such as an impedance matching system (IMS) 140. In the exemplary implementation configuration shown in Figure 1, the RF power supply includes two RF signal generators to supply power to the ESC. Thus, the first RF signal generator 141 is employed to supply RF power at approximately 60 MHz, and the second RF signal generator 142 is employed to supply RF power at approximately 400 kHz to the electrode 109 via the impedance matching system (IMS) 140. The RF power supply, including the first RF signal generator 141, the second RF signal generator 142, and the IMS 140, represents the main power supply of the process module, and the electrode 109 is defined as the main electrode. The RF power supplied to the electrode 109 is applied to a reactive gas (i.e., a gas species) introduced into a plasma processing region 180 defined above the ceramic layer 110 to create plasma for wafer processing operations such as etching. The edge ring 112 is positioned to surround the ceramic layer 110 and is configured to allow the plasma sheath to easily expand radially outward beyond the periphery of the wafer W to improve process results near the periphery of the wafer W. In addition to the edge ring, ESC, and RF power supply, the lower members of the plasma chamber also include a covering ring 114 positioned adjacent to and surrounding the edge ring 112. The covering ring 114 is made of insulating material. A gap is introduced adjacent to the edge ring 112, taking into account thermal expansion tolerances or mechanical tolerances.

[0029] An adjustable edge sheath (TES) assembly is mounted on the lower member of the plasma chamber to better control the plasma sheath characteristics of the plasma generated in the plasma processing area 180. The TES assembly is positioned below the edge ring 112 and controls the plasma sheath characteristics to better control the plasma sheath profile, particularly in the peripheral region of the wafer W. The TES assembly includes a TES electrode (also referred to as the "edge electrode") 158 positioned (embedded) within a TES ring (also referred to herein as the "connecting ring") 150. The TES ring 150 is positioned below a first portion of the edge ring 112 and is configured to surround at least a first portion of the electrode 109. In one mounting configuration, an electrically conductive gel 113 or a thermal gasket (not shown) is used to cover a portion of the upper part of the electrode 109 and the TES (connecting) ring 150 to secure the edge ring 112. In another mounting configuration, the edge ring 112 is mounted directly to the TES ring 150. In other configurations, other mounting means may be engaged to install the edge ring 112 so as to cover the electrode 109 and a portion of the TES ring 150. The ceramic support 118 is positioned below the TES ring 150 and is configured to surround a second portion of the electrode 109. An insulating component is embedded within the ceramic support 118 and extends for a predetermined first length from the top to the bottom of the ceramic support 118. In one configuration, the insulating component is a sleeve 122. In some configurations, the sleeve 122 is made of plastic or ceramic or other insulating material and protects and encloses the conductive rod 160. A TES radio frequency (RF) signal generator 154 is engaged to provide RF power to the TES electrode 158 through a TES impedance matching system (IMS) 152. Thus, the first end of the conductive rod 160 is connected to the TESRF signal generator 154 through the TESIMS 152, and the second end of the conductive rod 160 is connected to the TES electrode 158. In one implementation configuration, power from the TESRF signal generator 154 is supplied to the TES electrode 158 through the TESRF signal filter 156.The RF power generated by the TESRF signal generator 154 is transmitted to the conductive rod 160 through the TESIMS 152 and the TESRF signal filter 156 (if available). The conductive rod 160 extends by a second length, which is defined to include the first length of the sleeve 122 within the ceramic support 118 and the length within the TES ring 150 from the bottom surface of the TES ring 150 to the bottom of the TES electrode 158. The TES assembly is used to control the properties of the plasma near the periphery of the wafer W (such as controlling the properties of the plasma sheath, plasma density, and ion attraction or repulsion). By applying RF power to the TES electrode 158, the TES system can adjust the profile of the plasma sheath at the edge of the wafer, improving radial uniformity.

[0030] The base ring 116 is located below the second portion of the edge ring 112. The base ring 116 is positioned adjacent to and surrounding the TES ring 150 and a portion of the ceramic support 118, electrically insulating the components of the TES assembly. In one configuration, the base ring 116 is made of quartz. The groove 117 is located within a portion of the inner sidewall of the base ring 116 adjacent to the TES ring 150. The location of the groove 117 within the inner sidewall of the base ring 116 is specified to be above the upper surface of the ceramic support 118. The groove 117 is configured to extend from a first inner diameter ("FID1") to a second inner diameter ("FID2") of the base ring 116, where FID2 is larger than FID1. The groove 117 is configured to have dimensions suitable for accommodating the barrier seal ring 125. The barrier seal ring 125 is housed in the groove 117 and blocks the path defined by the gap between the TES ring 150 and the base ring 116. The grounding ring 120 is positioned to be at least adjacent to and surrounding a portion of the covering ring 114, the base ring 116, and a portion of the ceramic support 118. The barrier seal ring 125 is also referred to as the "plasma radical edge ring barrier seal" because it is used to block the path of plasma radicals so that they cannot pass through the gap defined between the edge ring and other components of the lower electrode.

[0031] Because it is constantly exposed to reactive radicals of the plasma, the surface of the edge ring 112 begins to erode. The gap between the edge ring 112 and the adjacent component (e.g., the covering ring 114), which is determined considering the allowance for thermal expansion or mechanical tolerance, becomes a passage for the plasma radicals to travel and erode the weaker material along the way. In some implementations, the TES assembly incorporates plastic shafts(s) in the design for encapsulating conductive rods(s). Referring to Figure 1, in the absence of the barrier seal ring 125, plasma radicals can travel along the gaps (e.g., the gap between the edge ring 112 and the covering ring 114, the gap between the edge ring 112 and the base ring 116, the gap between the coupling ring 150 and the base ring 116, etc.) and reach the sleeve 122. Plasma radicals can cause mechanical / material weakening of the sleeve 122, and such erosion not only shortens the useful life of the sleeve 122 but can also damage the conductive rods 160 encapsulated inside. As surface erosion of the edge ring 112 progresses with each process operation, the gap between the edge ring 112 and the adjacent component widens, allowing radicals to move more freely toward the target of attack (e.g., the sleeve 122 and the conductive rod 160).

[0032] In some implementations, the barrier seal ring 125 is positioned on the base ring 116, above the sleeve 122, and is used to effectively seal the gap between the base ring 116 and the TES ring 150. Placing the barrier seal ring 125 adjacent to the outer sidewall of the TES ring 150 prevents plasma radicals from reaching the lower components of the TES assembly (such as the sleeve 122). By preventing plasma radicals from traveling beyond the range of the barrier seal ring 125, it is ensured that the sleeve 122 is not exposed to plasma radicals, and that the integrity of the sleeve 122 (which may be made of plastic) and the conductive rod embedded inside is maintained. Such a configuration improves the mean time between cleanings (MTBC) and reduces the cost of replacing the sleeve 122 (i.e., reduces the cost of consumables (CoC)). Thus, after each cleaning cycle, the stored sleeve 122 can be reused multiple times.

[0033] In addition to the lower member 102, the plasma chamber of the process module 100 includes an upper member (not shown) for supplying reactive gases to the plasma processing area 180, and a side wall extending between the upper member and the lower member 102, sealing the plasma processing area 180. In some implementations, the lower member 102 also includes an exhaust port from which exhaust gases originating from the plasma processing operation are removed. In some implementations, the exhaust port may be connected to a vacuum device that provides suction force for removing the exhaust gases. In some implementations, the plasma chamber in the process module 100 is formed from aluminum. However, in other implementations, the plasma chamber can be formed from essentially any material that provides sufficient mechanical strength, has thermal performance capabilities, and has chemical compatibility with gaseous materials and other materials exposed during the plasma processing operation performed within the plasma chamber. At least one side wall of the plasma chamber includes an opening operated by a door for introducing and removing a semiconductor wafer W into the plasma chamber. In some implementations, the door is configured as a slit valve door.

[0034] In some configurations, the semiconductor wafer W is the substrate used in the manufacturing process. For ease of understanding and discussion, the semiconductor wafer W will hereafter be simply referred to as wafer W. However, it should be understood that in various configurations, wafer W can be essentially any type of substrate used in a plasma-based manufacturing process. For example, in some configurations, wafer W can be a substrate formed from silicon, SiC, or other substrate materials, and may include glass panels / substrates, metal foils, metal sheets, polymer materials, etc. Furthermore, in various configurations, wafer W may differ in shape, form, and / or size. For example, in some configurations, wafer W may correspond to a circular semiconductor wafer on which an integrated circuit device is defined. In other configurations, wafer W may correspond to a non-circular substrate (e.g., rectangular, elliptical, etc.). Similarly, in configurations where a circular wafer W is being processed, wafer W can have various diameters, such as 200 mm, 300 mm, 450 mm, or other sizes.

[0035] In the plasma chamber of the process module 100, the electrode 109 is formed from aluminum in one configuration. In another configuration, the electrode 109 can be formed from another electrically conductive material having equivalent mechanical strength and matching thermal and chemical properties. The ceramic layer 110 is configured to receive and support the wafer W during the performance of a plasma processing operation on the wafer W. In some configurations, the ceramic layer 110 includes a radial arrangement of two or more clamp electrodes (not shown) to generate an electrostatic force that holds the wafer W to the upper surface of the ceramic layer 110 during the plasma processing operation. In one configuration, the ceramic layer 110 includes two clamp electrodes (not shown) positioned diametrically opposite to each other and configured to operate bipolarly to provide a clamping force to the wafer W during the process operation. The clamp electrodes are connected to a direct current (DC) power supply configured to generate a controlled clamping voltage for holding the wafer W to the upper surface of the ceramic layer 110. The DC power supply is electrically connected to the clamp electrodes via the ceramic layer 110 and the electrode 109. A DC power supply is connected to a control system (not shown) through one or more signal conductors, allowing the clamping force supplied to the waiver W to be controlled by the control system.

[0036] Figure 2 shows an enlarged perspective view of the base ring 116 with the barrier seal ring 125 incorporated in one implementation configuration. A groove 117 is defined on the inner sidewall of the base ring 116. The location of the groove 117 is defined within the base ring 116 above the upper surface of the ceramic support 118 defined within the lower member 102 of the plasma chamber in the process module 100 (see, for example, Figure 1). The groove 117 is defined to have an inner sidewall having an upper inner radius defined at the top of the inner sidewall and a bottom inner radius defined at the bottom of the inner sidewall. The dimensions and shape of the barrier seal ring 125 are designed to fit within the dimensions and shape of the groove 117, allowing the barrier seal ring 125 to be easily and securely installed in the groove 117. The material of the barrier seal ring 125 is selected to withstand exposure to plasma radicals and is flexible, so that it is pressed into place in the groove 117 by applying appropriate force. The design and flexibility of the barrier seal ring 125 ensure that the gap between the TES ring 150 and the base ring 116 is completely covered, thereby preventing plasma radicals from finding a path to attack the sleeve 122.

[0037] Figure 3 is an enlarged vertical cross-sectional view of a barrier seal ring 125 used to seal the gap between the TES ring 150 and the base ring 116 of a TES assembly in one mounting configuration. The barrier seal ring 125 is defined by an outer seal leg 126 and an inner seal leg 127. The outer seal leg 126 is defined to extend vertically downward along the outer diameter "OD" by an outer height "h1". In one mounting configuration, the outer height h1 is defined to be approximately 4.7 mm to approximately 5.0 mm. In another mounting configuration, the outer height h1 is defined to be approximately 4.85 mm. In one mounting configuration, the outer seal leg 126 has a uniform thickness along its length. In one mounting configuration, the thickness of the outer seal leg 126 is defined to be approximately 1.32 mm to approximately 1.72 mm. In another mounting configuration, the thickness of the outer seal leg 126 can vary along its length. The upper and lower outer corners (i.e., corners along the outer diameter) of the outer seal leg 126 are designed to include chamfered portions (C1, C2). The profiles of the chamfered portions (C1, C2) of the upper and lower outer corners of the outer seal leg 126 are designed to match the outer shape of the inner radius of the corresponding upper and lower corners of the inner side wall of the groove 117 in which the barrier seal ring 125 is housed. The profile of the chamfered portion includes at least an angle and length between adjacent faces. In one configuration, the length of the upper outer chamfered portion C1 is defined as being equal to the length of the lower outer chamfered portion C2. In this configuration, the lengths of the chamfered portions C1 and C2 are defined as approximately 0.60 mm to approximately 1.0 mm. In another configuration, the lengths of the chamfered portions C1 and C2 are defined as approximately 0.8 mm. In other configurations, the length of the upper outer chamfer C1 differs from the length of the bottom outer chamfer C2, and the difference in length is determined by the outer shape of the groove 117 and the inner radii of the upper and bottom angles of the inner sidewall of the groove 117. In one configuration, the angles of the upper outer chamfer C1 and the bottom outer chamfer C2 are defined to be equal. In some configurations, the angles of the chamfers C1 and C2 are defined in relation to the outer diameter side of the barrier seal ring (for example, the angle of inclination of the chamfers C1 and C2 with respect to the outer sidewall of the barrier seal ring).In a different implementation, the angles of the chamfers C1 and C2 are determined in relation to the upper surface of the barrier seal ring 125. In some implementations, the angles of the chamfers C1 and C2 are defined as approximately 45°. In another implementation, the angles of the chamfers C1 and C2 are equal but greater than or less than 45°, depending on the profiles of the upper and lower angles of the inner sidewall of the groove 117. In one implementation, the upper and lower angles of the inner sidewall of the groove 117 are defined as right angles. In another implementation, the angle of the upper angle of the groove 117 is different from the angle of the lower angle, and both the upper and lower angles are less than 90°. In this implementation, the angles of the upper outer chamfer C1 and the lower outer chamfer C2 are defined to perfectly match the angle profiles of the upper and lower angles of the inner sidewall of the groove 117, and the angle of the upper outer chamfer C1 is different from the angle of the lower outer chamfer C2.

[0038] The inner seal leg 127 is defined to extend from the upper part of the inner surface of the outer seal leg 126 by an inner height "h2". In some mounting configurations, the profile of the inner seal leg 127 is defined to be different from the profile of the outer seal leg 126. In one mounting configuration, the profile of the inner seal leg 127 is angled with respect to the top surface, while the profile of the outer seal leg 126 is straight (i.e., perpendicular to the top surface). In one mounting configuration, the inner height h2 of the inner seal leg 127 is defined to be different from the outer height h1 of the outer seal leg 126. In one mounting configuration, height h2 is lower than height h1. In one mounting configuration, the inner height h2 of the inner seal leg 127 is defined to be approximately 4.45 mm to approximately 4.75 mm. In other mounting configurations, the inner height h2 of the inner seal leg 127 is defined to be approximately 4.6 mm. The inner seal leg 127 is defined by an upper leg portion 128, a lower leg portion 129, and an interface connecting the upper leg portion 128 and the lower leg portion 129. The upper leg portion 128 is connected to the upper part of the inner surface of the outer seal leg 126 and is oriented at an angle to the outer seal leg 126 so as to establish an initial gap 131 between the inner surface of the outer seal leg 126 and the inner surface of the lower leg portion 129 of the inner seal leg 127. In one implementation configuration, the angle at which the upper leg portion 128 extends with respect to the inner surface of the outer seal leg 126 is defined to be acute. In one implementation configuration, the lower leg portion 129 extends downward from the bottom surface of the upper leg portion 128 so that the inner surface of the lower leg portion 129 extends vertically downward and is substantially parallel (±5%) to the inner surface of the outer seal leg 126. The outer surface of the lower leg portion includes the upper and bottom portions of the lower leg. The upper portion of the lower leg extends by a first leg height "h5", and the bottom portion extends by a second leg height "h6". In one mounting configuration shown in Figure 3, the outer surface of the upper portion of the lower leg follows the contour of the outer surface of the upper leg portion 128, and the outer surface of the bottom portion of the lower leg extends vertically downward from the bottom of the upper portion of the lower leg so as to be substantially parallel (±5%) to the inner surface of the outer seal leg 126.It should be noted that the profiles of the outer and inner seal legs defined in this specification are examples only, and other profiles are also conceivable.

[0039] In one mounting configuration, the thickness of the inner seal leg 127 is uniform throughout the entire inner height h2. In another mounting configuration, the thickness of the upper leg portion 128 of the inner seal leg 127 differs from the thickness of the lower leg portion 129. In one mounting configuration, the thickness of the upper leg portion 128 is uniform (shown in Figure 3), and the thickness of the lower leg portion 129 is uniform (not shown). However, in some mounting configurations, the thickness of the upper leg portion 128 is greater than or less than the thickness of the lower leg portion 129. In another mounting configuration, the thickness of the upper leg portion 128 gradually increases from the top surface to the bottom surface. Similarly, the thickness of the lower leg portion 129 gradually increases from the top surface to the bottom surface, and the thickness of the upper leg portion 129 is equal to the thickness of the lower leg portion 128 at the bottom surface. As can be understood, the barrier seal ring 125 can have various profiles, each profile being defined, to name a few, by the outer shape and dimensions of the inner seal leg 127 and the outer seal leg 126, the angle at which the upper leg portion 128 is positioned relative to the inner surface of the outer seal leg 126, the desired initial clearance between the outer seal leg 126 and the inner seal leg 127, the profile of the outer surface of the inner seal leg, and so on.

[0040] The initial gap 131 can be adjusted by applying force to the inner seal leg, causing it to bend toward the outer seal leg. In one example, this force is applied during the installation of the TES ring 150. In one implementation, the initial gap 131 is reduced as the inner seal leg bends inward, defining the bend gap 132 (shown in Figure 5). In one implementation, the degree of inward bending differs between the upper leg portion 128 and the lower leg portion 129. For example, the upper leg portion 128 bends less inward than the lower leg portion 129. In this example, the height h1 does not change when the inner seal leg 127 is bent toward the outer seal leg 126. That is, the upper surface of the barrier seal ring 125 is configured not to move slightly upward or protrude when the inner seal leg 127 is moving toward the outer seal leg 126. Similarly, when the inner seal leg 127 is relaxed (i.e., separated) from the outer seal leg 126, the upper surface of the barrier seal ring 125 should not be depressed.

[0041] The bottom inner corner of the lower leg portion 129 is defined to include a chamfered portion C3. In one mounting configuration, the length of the chamfered portion C3 at the bottom inner corner of the inner seal leg 127 is defined to be approximately 0.4 mm to approximately 0.6 mm. In another mounting configuration, the length of the chamfered portion C3 is defined to be approximately 0.5 mm. In one mounting configuration, the angle of the chamfered portion C3 is defined so that the lower leg portion 129, and consequently the inner seal leg 127, can be easily bent.

[0042] In one mounting configuration, the angular profile of the inner seal leg 127 has different widths along the top and bottom surfaces of the barrier seal ring 125. In one mounting configuration, the barrier seal ring 125 extends by an upper width "w1" on the top surface and a lower width "w2" on the bottom surface. In one mounting configuration, the upper width w1 is defined as approximately 2.4 mm to approximately 2.8 mm. In other mounting configurations, the upper width w1 is defined as approximately 2.65 mm. In one mounting configuration, the lower width w2 is defined as approximately 4.2 mm to approximately 4.6 mm. In other mounting configurations, the lower width w2 is defined as approximately 4.4 mm.

[0043] In one mounting configuration, the groove 117 defined on the inner side wall of the base ring 116 extends from a first inner diameter "FID1" to a second inner diameter "FID2", with FID1 of groove 117 being smaller than FID2. FID1 of groove 117 is larger than the inner diameter "ID" of the barrier seal ring 125. Furthermore, in one mounting configuration, FID2 of groove 117 is equal to the outer diameter "OD" of the barrier seal ring 125. In another mounting configuration, FID2 of groove 117 is smaller than the OD of the barrier seal ring 125. In this configuration, when the barrier seal ring 125 is installed, OD is pressed against the inner side wall of groove 117 by force. In one mounting configuration, the outer diameter OD and inner diameter ID of the barrier seal ring 125, and the first inner diameter (FID1) and second inner diameter (FID2) of groove 117 depend on the size of the ESC. In one mounting configuration, the outer diameter OD of the barrier seal ring 125 is specified to be approximately 350 mm to 355 mm. In another mounting configuration, the outer diameter OD of the barrier seal ring 125 is specified to be approximately 352 mm. In yet another mounting configuration, the outer diameter of the barrier seal ring 125 is specified to be approximately 383 mm to 387 mm. In several mounting configurations, the outer diameter OD of the barrier seal ring 125 is specified to be approximately 385.5 mm.

[0044] The interface defined between the upper leg portion 128 and the lower leg portion 129 of the inner seal leg 127 is configured to allow the inner seal leg 127 to flex inward toward the inner surface of the outer seal leg 126. During installation, a force "F" is applied along the inner diameter ID of the barrier seal ring 125 (i.e., on the outer surface of the lower leg portion 129), and the design and materials used in the barrier seal ring 125 can cause the inner seal leg 127 to flex and bend inward toward the initial gap 131 and toward the outer seal leg 126. In one configuration, the degree to which the inner seal leg 127 can be bent is limited to the bending angle. In one configuration, the bending angle is determined to maintain the bending gap 132 between the tip of the outer seal leg 126 and the inner surface of the inner seal leg 127. The bending gap 132 is smaller than the initial gap 131, and in one mounting configuration, the deflection of the inner seal leg 127 is determined so as not to cause interference between the part / surface of the outer seal leg 126 and the groove 117 and the surface of the base ring 116. In another mounting configuration, the inner seal leg 127 can be bent so that the inner bottom corner of the inner seal leg 127, where the chamfered portion C3 is defined, contacts the inner wall of the outer seal leg 126 without leaving a bending gap 132. The degree to which the inner seal leg 127 can be bent is determined so as to ensure that a sufficient amount of the inner seal leg extends toward the TES ring 150 to close the gap between the TES ring 150 and the base ring 116. A force is applied to the barrier seal ring 125 during installation to ensure that the barrier seal ring 125 is properly seated in the groove 117 and that the outer surface of the outer seal leg 126 fits perfectly against the inner side wall of the groove 117. In one implementation configuration, the term "perfect fit" is defined by the length of the outer wall of the outer seal leg 126 being in complete contact with the length of the inner side wall of the groove 117. The chamfered portions C1 and C2 further assist in positioning the barrier seal ring 125 within the groove 117, and the chamfered portion C3 assists in the flexing of the inner seal leg 127.

[0045] Figure 4 shows additional features of the barrier seal ring 125 in one implementation configuration. As shown, the inner seal leg 127 includes an upper leg portion 128 and a lower leg portion 129. The upper leg portion 128 extends downward from the top surface of the barrier seal ring 125 by a height "h3", and the lower leg portion 129 extends downward from the bottom surface of the upper leg portion 128 by a height "h4". In this implementation configuration, the heights (h3, h4) of the upper leg portion 128 and the lower leg portion 129 are combined to determine the inner height "h2" of the inner seal leg 127. In one implementation configuration, the height h4 of the lower leg portion 129 is set such that there is sufficient space in the initial gap 131 to accommodate the folded lower leg portion 129 without touching (i.e., without contact with) the outer seal leg 126. This deflection ensures that a portion of the lower leg portion 129 of the barrier seal ring 125 is accommodated in the groove 117, while the inner seal leg 127 of the barrier seal ring 125 completely seals the gap between the TES ring 150 and the base ring 116. The length and angle of the inner chamfer C3 allow the lower leg portion 129 to easily fold into the initial gap 131 without interfering with the lower outer corner of the groove 117, while extending outward to seal the gap between the TES ring 150 and the base ring 116. Without the inner chamfer C3, the degree to which the outer seal leg 127 can be bent may be limited by one or more of the thickness of the lower leg portion 129 of the outer seal leg 127, the heights h1, h2 of the outer and outer seal legs, and the height of the groove 117. In other words, the bottom surface of the outer seal leg 127 may strike the lower outer corner of the groove 117, preventing the barrier seal ring from being fully seated in the groove 117 during installation. Furthermore, in one implementation configuration, the heights (h3, h4) of the upper and lower leg portions (128, 129) and the degree of deflection of the lower leg portion 129 are determined to ensure that when the lower leg portion 129 is bent, it does not exceed the outer height h1 of the outer seal leg 126. In one implementation configuration, the heights (h3, h4) of the upper and lower leg portions (128, 129) depend on the angle at which the upper leg portion 128 is positioned relative to the inner surface of the outer seal leg 126.In one mounting configuration, the height h3 of the upper leg portion 128 is greater than the height h4 of the lower leg portion 129. In another mounting configuration, the height h3 of the upper leg portion 128 is equal to or less than the height h4 of the lower leg portion 129. In one mounting configuration, the height h3 of the upper leg portion 128 is approximately 2.5 mm to 2.7 mm. In another mounting configuration, the height h3 of the upper leg portion 128 is defined as approximately 2.62 mm. In one mounting configuration, the height h4 of the lower leg portion 129 is defined as approximately 1.85 mm to 2.05 mm. In another mounting configuration, the height h4 of the lower leg portion 129 is defined as approximately 1.95 mm. In one mounting configuration, the angle at which the upper leg portion 128 extends from the inner surface of the outer seal leg 126 is defined by "α°", where α° is an acute angle. In one mounting configuration shown in Figure 4, α° is approximately 24°. In the other implementations shown in Figure 5, α° is approximately 20°.

[0046] The interface represents the interface between the upper leg portion 128 and the lower leg portion 129. In one implementation configuration, the interface is positioned at a height h3 from the top surface of the barrier seal ring 125 (i.e., the height of the upper leg portion 128). This interface allows the inner seal leg 127 to flex inward when a force F is applied to the outer surface of the lower leg portion 129.

[0047] Figure 5 shows different positional profiles of the barrier seal ring in one mounting configuration. The inner seal leg 127 is represented by both a solid and a dashed line. The solid line represents the inner seal leg 127, which corresponds to the barrier seal ring 125 in the relaxed position, while the dashed line represents the deflected position. The barrier seal ring 125 is moved to the deflected position by applying a force "F" to the outer surface of the lower leg portion 129 when the TES ring 150 is installed adjacent to the inner diameter of the barrier seal ring 125 housed within a groove 117 defined in the base ring 116. In the mounting configuration shown in Figure 5, the upper leg portion 128 of the barrier seal ring 125 is oriented at an angle α° to the inner surface of the outer seal leg 126, where α° is defined as an acute angle. When force F is applied, the inner seal leg 127 is pushed inward toward the outer seal leg 126. As a result, the upper leg portion 128 and the lower leg portion 129 are pushed inward. In one implementation, the amount by which the upper leg portion 128 is pushed inward is less than the amount by which the lower leg portion 129 is pushed inward. The degree to which the upper leg portion 128 and the lower leg portion 129 of the inner seal leg 127 flex is limited by the interface. In one implementation, the angled contour of the inner seal leg 127 causes the upper leg portion 128 of the inner seal leg 127 to be pushed inward (i.e., flex) by a first bending angle "a°", while the lower leg portion 129 of the inner seal leg 127 flexes / is pushed inward by a second bending angle "A°". In one implementation, the first bending angle a° of the upper leg portion 128 is smaller than the second bending angle A° of the lower leg portion 129. In another implementation, the first bending angle a° of the upper leg portion 128 is equal to the second bending angle A° of the lower leg portion 129. In one implementation, the first bending angle a° of the upper leg portion 128 is smaller than the angle α° at which the upper leg portion 128 is positioned relative to the inner surface of the outer seal leg 126. In one implementation, the second bending angle A° of the lower leg portion 129 is larger than the angle α° at which the upper leg portion 128 is positioned relative to the inner surface of the outer seal leg 126.In another implementation, the second bending angle A° of the lower leg portion 129 is less than or equal to the angle α° at which the upper leg portion 128 is positioned relative to the inner surface of the outer seal leg 126. In some implementations, the first and second bending angles (a°, A°) at which the upper and lower leg portions (128, 129) can be bent / compressed are determined based on the height h3 of the upper leg portion 128, the height h4 of the lower leg portion 129, the initial angle α° at which the upper leg portion 128 extends from the inner surface of the outer seal leg 126, the amount of the initial gap 131 established between the inner seal leg 127 and the outer seal leg 126 when the barrier seal ring 125 is in the relaxed position, the amount of the bending gap 132 that must be left between the inner seal leg 127 and the outer seal leg 126 when the barrier seal ring 125 is in the bent position, and the amount of force F applied to the outer surface of the lower leg portion 129. The bending gap 132 is determined to prevent interference between the outer seal leg 126 and the inner seal leg 127. In addition, the first and second bending angles, as well as the dimensions of the outer seal leg 126 and inner seal leg 127 (i.e., the upper leg portion 128 and the lower leg portion 129) are determined to ensure that there is no interference between the surface of the barrier seal ring 125 and the surfaces of the groove 117 and the base ring 116. In one mounting configuration, interference is the amount or degree to which the outer seal leg is prevented from being pushed into its position inside the groove 117, for example, by the lower outer angle of the groove 117 preventing the outer seal leg from bending. Furthermore, the first and second bending angles, the height h3 of the upper leg portion 128, and the height h4 of the lower leg portion 129 are all determined to ensure that when in the flexed position, the lower leg portion 129 does not exceed the outer height h1 of the outer seal leg 126.

[0048] It should be noted that the design, dimensions, and materials used to define the barrier seal ring 125 are all examples and should not be considered exhaustive or limiting. Furthermore, it should be noted that the use of the term "approximately" when defining the various dimensions (length and angle) of the barrier seal ring 125 may include a variation of ±10-15% from the given dimensions. In one implementation, the barrier seal ring 125 is made of a flexible material that is resistant to erosion by fluorine and / or other reactive components of plasma radicals, and that can be pressed into position within the groove of the base ring 116, so that the barrier seal ring 125 can be reused in multiple operations. In some implementations, the barrier seal ring 125 is made of polytetrafluoroethylene (PTFE) or perfluoroelastomer (FFKM) material. In another implementation, the barrier seal ring 125 may be made of the same or similar material as the O-ring used in the plasma chamber to prevent gas and fluid leakage. The barrier seal ring 125 is not limited to the aforementioned materials and can be made from any other material having the same or equivalent thermal and chemical properties.

[0049] In one implementation configuration, the barrier seal ring 125 may be subjected to annealing to maintain its original size when placed in the groove. The environment within the plasma chamber in which the barrier seal ring 125 is used can change based on the operations being performed. As a result, the barrier seal ring 125 may shrink, and it may no longer be able to prevent plasma radicals from flowing toward and attacking underlying parts such as insulating (plastic) components. To prevent the size and shape of the barrier seal ring 125 from being affected during use in the plasma chamber, the barrier seal ring is subjected to an annealing process before being placed in the groove 117 of the base ring 116. By undergoing annealing, the external shape of the barrier seal ring 125 is maintained during use, thereby ensuring that the function of the barrier seal ring 125 is not adversely affected by the conditions within the plasma chamber. The annealing process allows the barrier seal ring to retain its structure and size. The temperature and time used for annealing depend on the material used, and the aforementioned temperature and time ranges are examples only and should not be considered limiting.

[0050] Figure 6 is a side view of a top perspective view of a plasma radical edge ring barrier seal 125 usable in a plasma chamber. Because the barrier seal 125 is ring-shaped, it is also referred to throughout this application as a “barrier seal ring” 125. The barrier seal ring 125 is configured to be incorporated into a groove 117 defined on the inner surface of a base ring 116, which is located below an edge ring 112 surrounding an electrostatic chuck, which is part of the lower electrode of the plasma chamber of the process module 100. The barrier seal ring 125 is used to seal the gap between the base ring 116 and an adjustable edge sheath (TES) ring 150, which is part of a TES assembly located below the edge ring 112, and the TES assembly is used to provide power for controlling the plasma sheath profile on the edge ring 112. While various mounting configurations have been described using the barrier seal ring 125 that seals the gap between the base ring 116 and the TES ring 150, the barrier seal ring 125 can also be used to seal gaps between the edge ring 112 and the covering ring 114, between the edge ring 112 and the base ring 116, and between the covering ring 114 and the base ring 116.

[0051] Figure 7 is a side view of a barrier seal ring 125 configured to seal the gap between the base ring 116 and other components located beneath the edge ring 112.

[0052] Figure 8 is a top view of the barrier seal ring 125, and Figure 9 is a bottom view of the barrier seal ring 125 used in a plasma chamber. More detailed diagrams of the barrier seal ring 125 are shown and explained with reference to Figures 10A and 10B.

[0053] Figure 10A is a side view of the barrier seal ring 125, showing the location where an enlarged cross-sectional view of the barrier seal ring is provided in Figure 10B. Referring to Figures 10A and 10B together, the barrier seal ring 125 includes a pair of legs, the outer seal leg 126 is defined at an outer diameter OD and includes a side wall having chamfered portions (C1, C2) defined at the top and bottom surfaces of the side wall, and the inner seal leg 127 is defined to extend to an inner diameter ID and includes an upper leg portion 128 and a lower leg portion 129. The upper leg portion 128 extends at an angle from the top of the outer seal leg 126 so as to define an initial gap 131 between the outer seal leg 126 and the inner seal leg 127. Interface 130 is defined between the upper leg portion 128 and the lower leg portion 129, and the inner seal leg 127 is configured to bend inward toward the outer seal leg 126 at interface 130. The bending of the inner seal leg 127 is limited to define a bending gap 132 between the outer seal leg 126 and the inner seal leg 127. The bending gap 132 is intended to ensure that the outer seal leg 126 and the lower leg portion 129 of the inner seal leg 127 do not come into contact. The bending causes the barrier seal ring 125 to fit snugly into the groove 117, maximizing the height h1 of the outer seal leg 126 and minimizing the clearance of the base ring 116 within the groove 117. Furthermore, the outer height h1 of the outer seal leg 126 is determined to ensure that the barrier seal ring 125 does not excessively fill the groove height when the barrier seal ring 125 is exposed to the temperature inside the plasma chamber. The outer diameter OD of the barrier seal ring 125 is determined to ensure that sealing compression occurs during installation, allowing for reuse and easy installation of the barrier seal ring 125. The chamfered portions (C1, C2) provided on the outer corners of the outer seal leg 126 ensure that the barrier seal ring 125 fits perfectly into the inner surface of the groove 117 during installation (i.e., the chamfered portions C1, C2 contact the length portion of the inner side wall of the groove 117, except for the defined upper and bottom outer corners).The chamfered portion C3 provided on the inner corner of the lower leg portion 129 of the inner seal leg 127 allows the inner seal leg 127 to flex easily without contacting the outer corner of the groove 117 of the base ring 116 (i.e., the lower outer corner facing the TES ring 150). Without the chamfered portion C3, in some cases, the flexing of the inner seal leg 127 may damage the barrier seal ring 125 at the inner corner of the inner seal leg 127, or it may become difficult to push the inner seal leg 127 inward. The lower width w2 of the barrier seal ring 125 is determined to ensure contact between the barrier seal ring 125 and the TES ring 150 and to close the gap between the TES ring 150 and the base ring 116. The inner height h2 is determined to ensure space for the inner seal leg 127 to fold into the groove 117.

Claims

1. A barrier seal ring for a plasma chamber, wherein the barrier seal ring is An outer seal leg extending vertically downward in its outer diameter, having an upper chamfered portion and a lower chamfered portion on its outer surface, An inner seal leg connected to the upper part of the outer seal leg, which is oriented at an angle to the outer seal leg and includes an upper leg portion and a lower leg portion, wherein the lower leg portion of the inner seal leg forms an initial gap of a first distance between itself and the outer seal leg, The lower leg portion is configured to bend toward the outer seal leg and to form a second gap that is smaller than the first distance of the initial gap but greater than zero. A barrier seal ring in which the barrier seal ring is set in a groove of a first ring and is configured to seal when the inner seal leg is pressed against the second ring, and the first ring and the second ring are part of the plasma chamber.

2. A barrier seal ring according to claim 1, wherein the inner seal leg is oriented at an acute angle with respect to the outer seal leg, A barrier seal ring wherein the first ring is a base ring positioned below an edge ring surrounding a substrate support surface located at the bottom of the plasma chamber, and the second ring is a connecting ring positioned adjacent to the base ring and forming part of an adjustable edge sheath (TES) assembly surrounded by the base ring.

3. A barrier seal ring according to claim 1, wherein an interface within the inner seal leg connects the upper leg portion and the lower leg portion, the inner seal leg bends inward along the interface, and the degree of bending differs for the upper leg portion and the lower leg portion, respectively.

4. A barrier seal ring according to claim 3, wherein the upper leg portion bends at a first bending angle, the lower leg portion bends at a second bending angle, and the first bending angle is smaller than the second bending angle.

5. A barrier seal ring according to claim 3, wherein the inner surface of the lower leg portion extends vertically downward and is parallel to the inner surface of the outer seal leg, A barrier seal ring in which the outer surface of the lower leg portion includes an upper and a bottom portion, the upper portion extending by a first height along the contour of the outer surface of the upper leg portion, and the bottom portion extending vertically downward by a second height to the inner diameter of the barrier seal ring.

6. A barrier seal ring according to claim 3, wherein the outer seal leg extends to a first height in the outer diameter, the inner seal leg extends to the inner diameter by a second height, and the first height is greater than the second height. A barrier seal ring in which the upper leg portion extends by a third height, the lower leg portion extends by a fourth height, and the third and fourth heights determine the second height of the inner seal leg.

7. A barrier seal ring according to claim 1, wherein the inner seal leg has an inner chamfered portion defined on its inner surface.

8. A barrier seal ring according to claim 1, wherein the profiles of the upper chamfered portion and the lower chamfered portion match the profiles of the corresponding inner radii of the upper corner and bottom corner of the inner side wall of the groove of the first ring.

9. A barrier seal ring according to claim 1, wherein the upper width of the barrier seal ring is smaller than the bottom width of the barrier seal ring.

10. A barrier seal ring according to claim 1, wherein the groove is defined on the inner side wall of the first ring located at the lower part of the plasma chamber, and the groove extends inward from a first inner diameter to a second inner diameter, A barrier seal ring in which the second inner diameter of the groove of the first ring is equal to the outer diameter of the barrier seal ring, and the upper and lower chamfered portions of the outer seal leg of the barrier seal ring are configured such that the outer seal leg in the outer diameter fits perfectly into the inner side wall of the groove defined in the first ring.

11. A barrier seal ring according to claim 1, wherein the height of the groove defined within the first ring is equal to the first height of the outer seal leg in the outer diameter.

12. A barrier seal ring according to claim 10, wherein the first ring and the second ring are part of an adjustable edge sheath (TES) assembly located in the lower part of the plasma chamber, The first ring is positioned below the first portion of the edge ring surrounding the electrostatic chuck (ESC) located in the center of the lower part of the plasma chamber, The second ring is positioned below the second portion of the edge ring and includes a connector embedded within the second ring and close to the upper surface of the second ring, A ceramic support element positioned below the second ring and surrounding the ESC, comprising a sleeve housed within a vertical shaft extending to the height of the ceramic support element, wherein the sleeve is configured to enclose a conductive rod, and the ceramic support element is an insulating component. Includes a radio frequency (RF) power supply having a matched network, A barrier seal ring in which the first end of the conductive rod is connected to the RF power supply through the matching network, the second end of the conductive rod is connected to the connector embedded in the second ring, the conductive rod extends through the insulating component to the base of the connector in the second ring, and is configured to transmit power from the RF power supply to the edge ring such that it affects the sheath profile of the plasma generated in the plasma processing region of the plasma chamber and spreading to the edge ring.

13. A barrier seal ring according to claim 12, wherein a second RF power supply is connected to the ESC through a second matching network to provide power to the ESC for generating the plasma in the plasma processing region.

14. A barrier seal ring according to claim 1, wherein the barrier seal ring is annealed during use to prevent shrinkage of the barrier seal ring.

15. A barrier seal ring according to claim 1, wherein the barrier seal ring is made of polytetrafluoroethylene or a perfluoroelastomer material.

Images