Edge seal for lower electrode assembly

Side sealing of bottom electrode assembly

EDGE SEAL FOR LOWER ELECTRODE ASSEMBLY

This application is a partial continuation of the US patent application US 13/277,873 named "Edge Seal for Lower Electrode Assembly" filed on October 20, 2011, and the entire contents of which are incorporated by reference.

The present invention relates to the improvement of the side sealing of the lower electrode assembly used in a plasma processing chamber such as a plasma etching reactor.

Integrated semiconductor circuits have become the main components of most electronic systems. These miniaturized electronic devices may include thousands of transistors and other circuits that form the memory and logic subsystems of the microcomputer central processing unit and other integrated circuits. The low cost, high reliability, and speed of these circuits have made them popular features of modern digital electronic devices.

The manufacture of integrated semiconductor circuits is usually carried out in reactive ion etching systems such as parallel plate reactors or inductively coupled plasma reactors. The reactive ion etching system may include an etching chamber having an upper electrode or anode and a lower electrode or cathode therein. The cathode has a negative bias relative to the anode and the chamber wall. The wafer to be etched is covered by a suitable mask and placed directly on the cathode. Chemically reactive gases such as CF₄, CHF₃, CClF₃, HBr, Cl₂With SF₆Or with O₂, N₂The mixture of He, He or Ar is introduced into the etching chamber and maintained at a pressure generally in the range of millitorr. The upper electrode is provided with gas holes to allow gas to be evenly dispersed through the electrode and into the etching chamber. The electric field established between the anode and the cathode dissociates the reactive gas and forms a plasma. The surface of the wafer can be etched by the chemical action of active ions and the momentum transfer of the ion bombarding the surface of the wafer. The electric field generated by the electrode attracts ions to the cathode, causing the ions to bombard the surface mainly in a vertical direction, so that the process produces well-defined vertical etched sidewalls.

A lower electrode assembly for supporting a semiconductor substrate in a plasma processing chamber, comprising: an upper plate, a lower bottom plate whose temperature is controlled, a mounting groove surrounding the bonding layer in the lower electrode assembly, and a side seal containing an elastic band The elastic belt has an outer concave surface in an uncompressed state, and the elastic belt is installed in the groove so that the upper and lower ends of the elastic belt are axially compressed and the maximum outward protrusion of the elastic belt is not greater than A predetermined distance.

<p>10Plasma reactor</p><p>12Plasma processing room</p><p>14Gas distribution plate or sprinkler</p><p>16Planar coil</p><p>18RF generator</p><p>20Plasma spray coating</p><p>24RF Generator</p><p>26Leave the interface</p><p>28Bottom electrode assembly/substrate support</p><p>30Semiconductor substrate or wafer</p><p>32Wall</p><p>100Lower member/lower bottom plate</p><p>105Outer edge</p><p>120Joint layer</p><p>125Outer edge</p><p>140heating plate</p><p>145Outer edge</p><p>150Bottom electrode assembly</p><p>160Joint layer</p><p>165Outer edge</p><p>180Upper ceramic components</p><p>185Outer edge</p><p>190Upper member/installation groove</p><p>200Elastic Band</p><p>211Size/Depth</p><p>212Dimensions/Cylindrical part</p><p>212a, bSize</p><p>213Width</p><p>214Height</p><p>215Size</p><p>216Radius of curvature</p><p>218Solid line/Dotted line</p>

Figure 1 shows a cross-sectional view of a processing chamber suitable for plasma etching of semiconductor substrates.

Fig. 2 shows a cross-sectional view of an electrode assembly having a mounting groove between the upper ceramic layer and the lower base plate.

Fig. 3 shows a cross-sectional view of a rectangular elastic band placed in the mounting groove between the ceramic layer on the electrode assembly and the lower base plate.

4 shows a cross-sectional view of an elastic band with a concave outer surface installed in the installation groove between the ceramic layer on the electrode assembly and the lower base plate.

Figure 5 shows a cross-sectional view of an elastic band with a concave outer surface in an uncompressed state.

Fig. 6 shows a cross-sectional view of an elastic band having a concave outer surface in a compressed state, which compression causes the degree of compression in the axial direction to be 10 to 15 percent.

Fig. 7 shows a cross-sectional view of an elastic belt with an inclined outer surface installed in the installation groove between the upper ceramic layer and the lower base plate of the electrode assembly.

Fig. 8 shows a cross-sectional view of an elastic belt with an outer convergent surface installed in the installation groove between the upper ceramic layer and the lower base plate of the electrode assembly.

Fig. 9 shows a cross-sectional view of another embodiment of an elastic belt in an uncompressed state, the elastic belt having a concave outer surface and flat portions on the outer surface and the lower end.

Fig. 10 shows a cross-sectional view of another embodiment of an elastic band having a concave outer surface in an uncompressed state.

Fig. 11 shows a cross-sectional view of another embodiment of an elastic band having a concave outer surface in an uncompressed state.

The lower electrode assembly usually contains an electrostatic interlayer on which the wafer is sandwiched during processing in the plasma processing chamber. The bottom electrode assembly may also include various membrane layers connected to the temperature-controlled bottom plate. For example, the component may include an upper ceramic layer and a bottom plate, the upper ceramic layer includes one or more electrostatic electrodes adhesively bonded to the upper side of the heating plate and one or more heaters adhesively bonded to the bottom of the heating plate, and the bottom plate is adhesively bonded To heater and heating plate. In order to protect the exposed adhesive bonding layer, the heating plate has a smaller diameter than the ceramic layer and the bottom plate, and the side seal of the elastomer material is located in the installation groove between the ceramic layer and the bottom plate. In order to provide an effective seal, the side seal is axially compressed by 1 to 20%, preferably by about 5% to completely fill the installation groove. For an annular side seal with a rectangular cross section, this compression causes the outer surface of the seal to protrude outward and this outward expansion can contact the surrounding side ring. In order to solve this problem, side seals are configured to solve the dimensional changes caused by radial expansion.

In order to protect the joint layer, the side seal may include an elastic band with a concave outer surface. When the elastic band is installed in the installation groove, the axial compression of the elastic band makes the elastic band The expansion of the outer surface does not exceed a predetermined distance such as the maximum outer diameter of the elastic band in an uncompressed state. The elastic band is designed so that it can be installed in the rectangular installation groove so that the elastic band is restricted on three sides but the fourth side is not restricted and exposed to the reaction chamber conditions, thereby protecting the bonding layer.

FIG. 1 shows a cross-sectional view of an exemplary plasma reactor 10 used to etch a substrate. As shown in FIG. 1, the plasma reactor 10 includes a plasma processing chamber 12 and an antenna provided on the processing chamber 12 to generate plasma, where the antenna is embodied by a planar coil 16. The RF coil 16 is usually energized by an RF generator 18 through a matching network (not shown). This type of processing chamber is called an inductively coupled plasma (ICP) chamber. In order to supply the processing gas to the inside of the processing chamber 12, a gas distribution plate or shower head 14 is provided. The gas distribution plate or shower head 14 preferably includes a plurality of holes to release gaseous source materials such as etchant source gas to the spray In the RF-induced plasma region between the shower head 14 and the semiconductor substrate or wafer 30 supported on the bottom electrode assembly 28. Although the inductively coupled plasma reactor is shown in FIG. 1, the plasma reactor 10 may include other plasma generating sources such as capacitively coupled plasma (CCP), microwave, magnetron, spiral or other suitable plasma generating equipment, wherein The antenna is omitted.

The gaseous source material can also be introduced into the processing chamber 12 by other configurations such as one or more gas injectors extending through the upper wall and/or a gas injection port built in the chamber wall of the processing chamber 12. When etching through aluminum or one of its alloys, the etchant source chemicals include, for example, halogens such as Cl₂With BCl₃. Other etchant chemicals (such as CH₄, HBr, HCl, CHCl₃) And the polymer forming species used to passivate the sidewalls of the etched features such as hydrocarbons, fluorocarbons, and hydrogen-fluorocarbons Things. These gases can be used with selective inert gases and/or non-reactive gases.

In use, the wafer 30 is introduced into the processing chamber 12 defined by the chamber wall 32 and the wafer 30 is placed on the lower electrode assembly 28. The wafer 30 is preferably biased by a radio frequency generator 24 (and generally by a matching network). The wafer 30 may include a plurality of integrated circuits (ICs) fabricated thereon. ICs, for example, can include logic elements such as PLAs, FPGAs and ASICs or memory elements such as random access memories (RAMs), dynamic RAMs (DRAMs), synchronous DRAMs (SDRAMs) or read-only memories (ROMs). When RF energy is supplied, the reactive species (formed from the source gas) will etch the exposed surface of the wafer 30. Then, by-products that may be volatile are discharged through the exit interface 26. After the processing is completed, the wafer 30 can be further processed, and finally diced and separated into individual wafers.

The exposed plasma surface (not shown), chamber wall 32, chamber liner (not shown) and/or spray head 14 of any plasma limiting device may be provided with a plasma spray coating 20, which has a rough surface. Features to promote polymer adhesion. In addition, the exposed plasma surface of the substrate support 28 may also be provided with a plasma spray coating (not shown). In this way, substantially all surfaces of the confined plasma will have surface roughness characteristics that can promote polymer adhesion. In this way, particulate contamination in the reactor can be substantially reduced.

It should be understood that the reactor 10 can also be used for metal, dielectric materials and other etching processes. In the plasma etching process, the gas distribution plate can be a circular plate directly below the dielectric window in the ICP reactor or form part of the upper electrode assembly in the CCP reactor (called a parallel plate reactor), where the gas distribution plate It is a shower head electrode oriented parallel to the semiconductor substrate or wafer 30. The gas distribution plate/shower head electrode contains an array of holes with a specific diameter and spatial distribution to optimize the etching uniformity of the film layers to be etched on the wafer, such as the photoresist layer, the silicon dioxide layer, and the underlying material.

An exemplary parallel plate plasma reactor that can be used is a dual-frequency plasma etching reactor (see, for example, a common US Patent No. 6,090,304, all of which is incorporated herein by reference). In this type of reactor, the etching gas can be supplied to the showerhead electrode from the gas supply source, and RF energy can be supplied to the showerhead electrode and/or the lower electrode from the two RF sources at different frequencies to be in the reactor. Generate plasma. Alternatively, the showerhead electrode can be electrically grounded and RF energy at two different frequencies can be supplied to the lower electrode.

2 shows a cross-sectional view of the bottom electrode assembly 150. The bottom electrode assembly 150 has various film layers joined together by the exposed bonding layer in the mounting groove. The mounting groove is used to accommodate the side seal containing the elastic band. . The electrode assembly 150 includes an upper ceramic member 180 that includes electrostatically sandwiched electrodes and is connected to the lower member 100 such as a temperature-controlled bottom plate. Disposed between the upper member 180 and the lower member 100 is a heating plate 140. The heating plate 140 includes a metal or ceramic plate and one or more heating plates. The heater is a thin film heater coupled to the bottom of the board. The adhesive bonding layer 120 is disposed between the lower member 100 and the heating plate 140 and joins the lower member 100 to the heating plate 140. The adhesive bonding layer 160 is disposed between the upper member 180 and the heating plate 140 and joins the upper member 180 to the heating plate 140. The upper member 180 and the lower member 100 extend beyond the heating plate 140 and the bonding layers 120 and 160 to form an annular groove 190. The heating plate 140 and the outer edges 145, 125, and 165 of the bonding layers 120 and 160 are substantially aligned with each other. The outer edges 185, 105 of the upper member 180 and the lower member 100 may or may not be vertically aligned and an additional film layer may be included between the upper and lower members.

The upper member 180 is preferably an electrostatic interlayer of ceramic material and an embedded electrode made of metal material such as W, Mo and the like. In addition, the upper member 180 preferably has a uniform thickness or diameter from the center to the outer edge. The upper member 180 is preferably a thin circular plate suitable for supporting 200mm, 300mm or 450mm diameter wafers. The details of the electrode assembly with the upper electrostatic interlayer, the heating layer and the bonding layer are disclosed in the common US patent application US 2006/0144516, wherein the upper electrostatic interlayer has a thickness of about 0.04 inches and the upper bonding layer has a thickness of about 0.004 inches. Thickness, the metal-containing heating plate or ceramic plate has a thickness of about 0.04 inches, the heating film has a thickness of about 0.01 inches, and the lower bonding layer has a thickness of about 0.013 to 0.04 inches. The rectangular mounting groove between the upper mezzanine layer and the bottom plate has a height of at least about 0.05 to 0.09 inches and a width of about 0.035 inches. In a preferred embodiment for processing 300 mm wafers, the trench has a height of at least about 0.07 inches and a width of about 0.035 inches. When the side seal is inserted into the groove, the side seal preferably expands radially and compresses vertically to fit tightly into the groove. However, if the side seal has a rectangular cross-section, it will protrude outward and may contact the surrounding side ring and/or the tensile stress on the outer surface of the side seal may be when it is exposed to fluorine or oxygen plasma. Will cause rupture.

The lower bottom plate 100 is preferably a circular plate having an upper surface and a lower surface. In one embodiment, the lower member 100 can be used to provide temperature control by including a fluid pipe (not shown) therebetween, wherein the temperature-controlled liquid can be circulated to the electrode assembly 150 through the fluid pipe. In the electrode assembly 150, the lower member 100 is usually a metal bottom plate that functions as a lower RF electrode in the plasma chamber. The lower member 100 preferably comprises anodized aluminum or aluminum composite. However, it should be understood that any suitable materials can be used, including metals, ceramics, conductive materials, and dielectric materials. In one embodiment, the lower member 100 is formed of anodized processed aluminum block. Alternatively, the lower member 100 may be a ceramic material having one or more electrodes located therein and/or on its upper surface.

As shown in FIG. 2, the bonding layer 120 bonds the lower member 100 to the heating plate 140. The bonding layer 160 bonds the upper member 180 to the heating plate 140. Bonding layers 120, 160 are preferably low modulus Materials such as elastomer silicone resin or silicone material are formed. However, any suitable bonding material can be used. It should be understood that the thickness of the bonding layer 120, 160 can be changed according to the desired thermal conductivity. Therefore, the thickness of the bonding layer can be adjusted based on the manufacturing tolerance to provide the desired thermal conductivity. Generally speaking, the bonding layers 120 and 160 will change positively and negatively by a specific variation value according to their applied area. Generally speaking, if the thickness of the bonding layer does not change by more than 1.5%, the thermal conductivity coefficient between the upper and lower members 190 and 100 can be made substantially uniform.

For example, for the electrode assembly 150 used in the semiconductor industry, the bonding layers 120 and 160 preferably have a chemical structure that can withstand a wide temperature range. Therefore, it can be understood that the low modulus material may include any suitable material, such as a polymer material that is compatible with a vacuum environment and is not easily thermally degraded at high temperatures (for example, up to 500° C.). In one embodiment, the bonding layers 120 and 160 may include silicone and may have a thickness ranging from about 0.001 to about 0.050 inches, preferably from about 0.003 to about 0.030 inches.

The heating plate 140 may include a laminate bonded to the lower surface of the upper member 180. For example, the heating plate 140 may have the following form: a metal or ceramic plate with a thin film heater coupled to the bottom of the metal or ceramic plate. The heater film may be a foil stack (not shown) including a first insulating layer (for example, a dielectric layer), a heating layer (for example, one or more resistive materials), and a second insulating layer (for example, a dielectric layer). The insulating layer is preferably composed of a material with the following characteristics, such as Kapton® or other suitable polyimide film: it can maintain its physical, electrical and mechanical properties in a wide temperature range, including its energy in a plasma environment. Resist corrosive gases. The heater elements (plural elements) are preferably made of high-strength alloys such as Inconel® or other suitable alloys or corrosion-resistant and heat-resistant materials. Generally speaking, the thin film heater has a laminated form of Kapton® and Inconel®, and Kapton® has a total thickness of about 0.005 to about 0.009 inches, more preferably a thickness of about 0.007 inches.

As shown in FIG. 2, the outer edges 105, 185 of the lower member 100 and the upper member 180 can extend beyond the outer edges 145, 125, and 165 of the heating plate 140 and the bonding layer 120, 160, thereby forming an installation in the electrode assembly 150groove190. Groove 190. The materials (multiple materials) of the bonding layers 120 and 160 are generally not resistant to the reactive etching chemicals of the semiconductor plasma processing reactor, and therefore must be protected to achieve useful operating life. In order to protect the bonding layers 120 and 160, it is suggested to place a side seal in the form of an elastic band in the groove 190 to form a tight seal that can prevent the corrosive gas from penetrating the semiconductor plasma processing reactor. See, for example, the co-owned US patent applications US 2009/0290145 and US 2010/0078899.

FIG. 3 shows a cross-sectional view of an electrode assembly 150 including an annular elastic band 200 having a rectangular cross-section. When the elastic band 200 is placed in the groove 190, the elastic band 200 is axially compressed so that The inner wall protrudes away from the outer surface of the heating plate 140 and makes the outer wall convex. In order to accommodate the larger diameter of the elastic band, the surrounding side ring needs to expand its inner diameter, otherwise the parts will contact each other and the friction of the thermal cycle may generate particles in the plasma chamber. In order to solve this problem, the elastic band can be changed so that it has a shape that can avoid unintended protrusion when it is axially compressed in the groove.

FIG. 4 shows a cross-sectional view of the electrode assembly 150 and the improved side seal including the elastic band 200. As shown in FIG. The electrode assembly 150 of FIG. 4 is the same as the electrode assemblies of FIGS. 2 and 3 but the elastic band 200 has a concave outer surface to reduce protrusion when the elastic band is axially compressed in the groove 190. "Concave" as used herein means that the outer surface does not have a uniform diameter, but has a concave surface formed by one or more curved or inclined surfaces along all or part of the outer surface. The inner surface may have a uniform diameter or the inner surface may also have a concave surface. The outer surface may include one or more cylindrical portions of uniform diameter at the upper and/or lower ends of the elastic band.

The elastic band 200 can be constructed from any suitable material that matches the semiconductor processing. For example, a curable fluoroelastomer fluoropolymer (FKM) or a curable fluoroelastomer perfluoropolymer (FFKM) that can be cured to form a fluoroelastomer can be used. The elastic band 200 is preferably constructed of polymers such as fluorocarbon polymer materials such as Teflon® (PTFE-polytetrafluoroethylene, manufactured by DuPont). However, wall glues, polymer materials, perfluoroalkoxides (PFA), fluorinated polymers and polyimides can be used. The elastic band 200 is preferably composed of materials with the following characteristics: high chemical resistance, low and high temperature capability, resistance to plasma corrosion in the plasma reactor, low friction, electrical and thermal insulation characteristic. A preferred material is a perfluoroelastomer having a Shore A hardness of 60 to 75A and a specific gravity of 1.9 to 2.1, such as PERLAST sold by Perlast Ltd. Another elastic band material is KALREZ sold from DuPont Performance Elastomers. Both PERLAST and KALREZ are FFKM elastomers.

Preferably, the elastic band 200 is composed of materials with the following characteristics: high chemical resistance, low and high temperature capability, resistance to plasma corrosion in the plasma reactor, low friction, and more than 85 Ideally Shore A hardness less than 75, electrical and thermal insulation properties. A more preferred elastic band is an unfilled elastomer and each metal element has a metal content of less than 5000 parts per billion, because the metal in the elastomer will generate particles and metal contamination on the semiconductor substrate during operation.

FIG. 5 shows a cross-sectional view of the elastic band 200 placed in front of the groove 190 in an uncompressed state. As long as the size of the elastic band 200 can form or be suitable for forming a tight seal in the mounting groove of the electrode assembly to minimize (if not eliminated) outward protrusion, the size of the elastic band 200 is not particularly limited. Preferably, the geometric size of the elastic band is designed to accommodate up to 20%, preferably up to 1-15%, and more preferably To 1-10% axial compression and minimize the extent to which the elastic band protrudes beyond its maximum outer diameter in the uncompressed state. For design to support 200 or 300 For the substrate support of a mm wafer, the maximum outward protrusion caused by the axial compression is preferably 0.004 inch, more preferably 0.002 inch. In one embodiment, the elastic band includes an inner cylindrical surface with a uniform diameter, a flat annular upper surface, a flat annular lower surface with a width smaller than the upper surface, and a concave outer surface. In a preferred embodiment, the elastic band may have a height of about 0.131 inches and a maximum width of about 0.035 inches, and the outer surface includes an upper cylindrical portion with a uniform diameter extending perpendicularly from the upper surface of about 0.01 inches, and a cylindrical surface from the upper An extended curved surface with a radius of about 0.35 inches and a selective lower cylindrical surface extending perpendicularly from the lower surface. Each corner of the elastic band is preferably rounded to have a radius of 0.002 to 0.01 inches. For other groove sizes, the height 214 of the elastic band 200 is not particularly limited, and it can be between about 0.05 and about 0.15 inches. The width 213 of the elastic band 200 is not particularly limited, and it may be between about 0.02 to about 0.10 inches, such as 0.025 to 0.050 inches. The size 211 is the recessed depth of the elastic band 200. This size is not particularly limited, and it can be between about 0.001 to about 0.010 inches or between about 0.001 to about 0.07 inches. The size 212 is an optional flat portion of the elastic band 200 according to the present invention, because the recess does not need to extend the entire height 214 of the elastic band 200. The selective flat portion can help reduce the corrosion rate of the elastic band 200 and the bonding layers 120 and 160 protected by the elastic band 200. The size 212 can be from about 0.01 to about 0.1 inches. The depression of the elastic band 200 may have a radius of curvature of from about 0.2 to about 0.8 inches or may be formed by one or more inclined surfaces.

In another embodiment, the recess of the elastic band 200 may have a radius of curvature of from about 0.02 to about 0.8 inches or be formed by one or more inclined surfaces.

FIG. 6 shows the elastic band 200 in a compressed state (for example, it has been inserted into the groove of the electrode assembly). The compressed state represents the compression of the height 214 of the elastic band 200 when the elastic band 200 is inserted into the groove of the electrode assembly. Usually the compression is roughly between 1%-20% or between 1%-15%, more specifically between 1-10%, and optimally about 5%. In other words, if the height 214 of the elastic band 200 when it is not compressed is 1.0 inches, a 10% compression will cause the elastic band 200 to have a height 214 of 0.9 inches. The size 215 is a predetermined distance corresponding to the allowable protrusion tolerance of the elastic band 200 under a certain compression rate. In the compressed state, the elastic band 200 may retain its concave characteristic as shown by the dashed line 218 or not retain its concave characteristic as shown by the solid line 218. However, as long as the degree of protrusion does not allow the elastic band to contact the surrounding side loops, the elastic band may protrude beyond the line 218. For example, the size 215 may be set so that the allowable protrusion margin does not allow the elastic band 200 to extend significantly beyond the outer edges 185, 105 of the upper member 180 and the lower member 100. The size 215 can be between about 0.001 to about 0.01 inches, preferably less than about 0.004 inches. If the optional cylindrical part 212 (Shown in FIG. 5) is included in the upper part of the elastic band, the size 215 can be limited to less than 0.004 inches, and when the remaining outer surface has a radius of curvature 216 of about 0.35 inches, the height is about 0.01 inches. The preferred height-to-thickness ratio (height:thickness) of the elastic band is 2 to 5.

In another embodiment, if the optional cylindrical portion 212 (shown in FIG. 5) is included at the upper part of the elastic band, the size 215 can be limited to less than 0.004 inches. When the remaining outer surface has a size of about 0.04 inches When the radius of curvature is 216, the height is about 0.01 inches.

The method of manufacturing the electrode assembly 150 with the elastic band 200 is not particularly limited, and it may include heating the elastic band to expand it and pressing the heated elastic band into the groove between the upper and lower members. In another method, before joining the upper member to the heating plate, the elastic band is expanded and installed near the heating plate. In use, the elastic band can protect the bonding layer during the processing of the wafer supported on the upper member.

FIG. 7 shows a cross-sectional view of an elastic belt 200 according to another embodiment, wherein the outer surface of the elastic belt is a slanted surface with a specific face to make the upper end of the elastic belt wider.

FIG. 8 shows a cross-sectional view of the elastic belt 200, wherein the outer surface of the elastic belt includes two convergent surfaces, and the two convergent surfaces form an angle of less than 180° with respect to each other. For example, the angle formed by the two surfaces may be between 110° and 140°, preferably about 120°.

FIG. 9 shows a cross-sectional view of an elastic band 200 according to another embodiment, wherein the elastic band 200 is in an uncompressed state before being inserted into the groove 190. Preferably, the geometric dimensions of the elastic band are designed to accommodate up to 20%, preferably 1-15% of the axial compression, and to minimize the protrusion of the elastic band beyond its maximum outer diameter in an uncompressed state degree. For a substrate support designed to support 200 or 300 mm wafers, the maximum outward protrusion caused by axial compression is preferably 0.004 inches, more preferably 0.002 inches. In one embodiment, the elastic band includes an inner cylindrical surface with a uniform diameter, a flat ring-shaped upper surface, a flat ring-shaped lower surface, and an outer surface. The outer surface includes an outer upper cylindrical portion of uniform diameter extending from the annular upper surface, an outer lower cylindrical portion of uniform diameter extending from the annular lower surface, and a uniform extending between the outer upper cylindrical portion and the outer lower cylindrical portion Radius of curved surface.

Preferably, the height 214 of the elastic band 200 is about 0.087 inches and the width 213 is about 0.031 inches. The inner diameter of the elastic band 200 is approximately 11.3 inches. The size 211 is the concave depth of the elastic band 200, which is about 0.013 inches. The dimensions 212a, b are the heights of the upper cylindrical surface and the outer lower cylindrical surface of the elastic band 200, because the recess does not need to extend the entire height 214 of the elastic band 200. Dimensions 212a, b have a height of about 0.01 inches. The outer upper cylindrical surface and the outer lower cylindrical surface can help reduce the elastic band 200 and the elasticity The corrosion rate of the bonding layer 120 and 160 protected by the belt 200. The radius of curvature 216 of the curved surface of uniform radius extending between the outer upper cylindrical surface and the outer lower cylindrical surface is preferably about 0.04 inches. Each corner of the elastic band is preferably rounded to have a radius of 0.002 to 0.01 inches.

FIG. 10 shows a cross-sectional view of an elastic band 200 according to another embodiment, wherein the elastic band 200 is in an uncompressed state before being inserted into the groove 190. Preferably, the height 214 of the elastic band 200 is about 0.087 inches and the width 213 is about 0.031 inches. The inner diameter of the elastic band 200 is approximately 11.3 inches. The depth 211 of the elastic band 200 is about 0.01 inches. The recess of the elastic band 200 may have a radius of curvature 216 of about 0.085 inches. Each corner of the elastic band is preferably rounded to have a radius of 0.002 to 0.01 inches.

FIG. 11 shows a cross-sectional view of an elastic band 200 according to another embodiment, wherein the elastic band 200 is in an uncompressed state before being placed in the groove 190. Preferably, the height 214 of the elastic band 200 is about 0.087 inches and the width 213 is about 0.031 inches. The inner diameter of the elastic band 200 is approximately 11.3 inches. The recess of the elastic band 200 may have a radius of curvature 216 ranging from about 0.02 to 0.8 inches, preferably about 0.20 inches. Each corner of the elastic band is preferably rounded to have a radius of 0.002 to 0.01 inches.

In a preferred embodiment, the electrode assembly 150 is an electrostatic chuck used to clamp a substrate such as a semiconductor wafer during processing in a vacuum processing chamber for semiconductor manufacturing, such as a plasma reactor such as a plasma etching reactor. (ESC). ESC can be unipolar or bipolar design. However, the electrode assembly 150 used for other purposes such as clamping the substrate during chemical vapor deposition, sputtering, ion implantation, photoresist stripping, and the like can be used.

The electrode assembly 150 includes an upper ceramic member 180. The ceramic member 180 may have a thickness of about 1 or 3 mm. The corrosion pattern of the elastic belt 200 depends on the thickness of the ceramic plate, because the elastic belt of such an embodiment can have various sizes to accommodate different corrosion patterns.

It should be understood that the electrode assembly 150 can be installed in any new processing chamber suitable for plasma processing of semiconductor substrates or used to retrofit an existing processing chamber. It is understood that in a specific system, the specific shapes of the upper member 180, the lower member 100, and the heater 140 may vary according to the configuration of the chuck, the substrate, and/or other components. Therefore, the actual shapes of the upper member 180, the lower member 100 and the heater 140 as shown in FIGS. 2-11 are only used to illustrate the present invention and not to limit the present invention in any way.

The side seal can be installed in other lower electrode assemblies that do not include a heating plate. For example, the elastic band can be installed in the mounting groove surrounding the bonding layer, the bonding layer is located in the lower electrode assembly with the upper plate and the temperature-controlled bottom plate, wherein the elastic band is installed in the groove to make the elastic band The upper and lower ends of the elastic band are compressed and the maximum outward protrusion of the elastic band is no more than a predetermined distance.

Compared to elastic bands with rectangular cross-sections, the side seals disclosed herein can provide advantages. For example, a side seal with a concave outer surface can provide better serviceability for the lower electrode assembly in a processing chamber such as a plasma etching chamber. This better serviceability is due to the following factors: when the side seal is axially compressed in the installation groove, the outer surface is less susceptible to rupture, and the side seal is less likely to engage with surrounding parts such as the side ring. If desired, the elastic band may include a geometric feature such as one or more grooves or protrusions such as dimples on its inner surface. When the elastic band is installed in the groove, such features can provide an easy identification indication of which surface should face the groove.

The term "approximately" used for the size in this article means plus or minus 10% of the size.

Although the present invention has been described in terms of preferred embodiments, those skilled in the art should understand that the present invention can be carried out without departing from the spirit of the present invention and the scope defined by the scope of the appended patent application. Clearly indicated additions, deletions, modifications and replacements.