Electrostatic chuck with ceramic coating adhesion

Abstract

An electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages are in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug extends from a first surface of the baseplate to a first end of a gas passage, wherein each of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface. A plurality of ceramic plug coatings are on sides of the plurality of porous ceramic plugs, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug, wherein the combination of the porous ceramic plug and the ceramic plug coating form a flange. A ceramic coating is on at least the first surface of the baseplate.

Description

ELECTROSTATIC CHUCK WITH CERAMIC COATING ADHESION CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority of U.S. Application No. 63 / 519,979, filed August 16, 2023, which is incorporated herein by reference for all purposes.BACKGROUND

[0002] The disclosure relates to an apparatus for processing substrates. More specifically the disclosure relates to an apparatus for plasma processing substrates.

[0003] In various plasma processing chambers, helium (He) is flowed to a backside of a substrate on an electrostatic chuck (ESC) in order to provide temperature control. Radio frequency (RF) power used for forming a plasma may cause a secondary plasma light-up in the ESC cavities due to the high voltage associated with plasma formation. The light-up would promote arcing between any two surfaces with a high electric potential difference between them. Such arcing will cause damage to the ESC. Ceramic plugs are provided for reducing arcing. A ceramic coating is provided to protect the baseplate of the ESC.SUMMARY

[0004] To achieve the foregoing and in accordance with the purpose of the present disclosure, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages are in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface. A plurality of ceramic plug coatings is on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug, wherein the combination of the porous ceramic plug and the ceramic plug coating forms a flange so that a diameter of the combination of the porous ceramic plug and the ceramic plug coating at the second end of the porous ceramic plug is less than a diameter of the combination of the porous ceramic plug and ceramic plug coating between the first end and the second end of the porous ceramic plug. A ceramic coating is on at least the first surface of the baseplate.

[0005] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages are in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug of the plurality of porousceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface. A plurality of ceramic plug coatings is on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug. A plurality of adhesive coatings is provided, wherein each adhesive coating of the plurality of adhesive coatings is between a ceramic plug coating of the plurality of ceramic plug coatings and the baseplate. A ceramic coating is on at least the first surface of the baseplate.

[0006] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface. A plurality of ceramic plug coatings is provided on the sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug. A plurality of expansion washers is provided wherein each expansion washer of the plurality of expansion washers is between the second end of a porous ceramic plug of the plurality of porous ceramic plugs and the baseplate. A ceramic coating is on at least the first surface of the baseplate.

[0007] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface. A plurality of ceramic plug coatings is on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug. A ceramic coating is on at least the first surface ofthe baseplate, wherein part of the ceramic coating on the first surface of the baseplate has a thickness in a range of 100 pm to 550 pm, and part of the ceramic coating on at least the first surface of the baseplate has a thickness of greater than 1200 pm.

[0008] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface, wherein each porous ceramic plug has a thickness in a range of 0.5 mm to 2 mm. A plurality of ceramic plug coatings is on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug. A ceramic coating is on at least the first surface of the baseplate.

[0009] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is in the baseplate. A plurality of porous ceramic plugs is provided wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface. A plurality of ceramic plug coatings is on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug. A ceramic coating is on at least the first surface of the baseplate, wherein the ceramic coating extends between the plurality of ceramic plug coatings and the baseplate.

[0010] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is in the baseplate. A plurality of plug holes is in the baseplate, wherein an end of each of the plug holes at a surface of the baseplate is chamfered. An anodization layer is on a surface of the baseplate, wherein the anodization layer does not extend on the chamfer of the plug holes. A plurality of porous ceramic plugs is provided, wherein each porous ceramic plug of the plurality of porous ceramic plugs is in a plug hole of theplurality of plug holes. A plurality of ceramic plug coatings is on the sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coating. A ceramic coating is on at least a first surface of the baseplate, wherein the anodization layer is between the ceramic coating and the surface of the baseplate.

[0011] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is in the baseplate. A plurality of plug holes is in the baseplate, wherein an end of each of the plug holes at a surface of the baseplate is chamfered. A plurality of porous ceramic plugs is provided, wherein each porous ceramic plug of the plurality of porous ceramic plugs is in a plug hole of the plurality of plug holes. A plurality of ceramic plug coatings is on the sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the plurality of porous ceramic plugs and the plurality of ceramic plug coatings do not contact the baseplate. A ceramic coating is on at least a first surface of the baseplate.

[0012] In another manifestation, an electrostatic chuck is provided. A baseplate comprises an electrically conductive body. A plurality of gas passages is provided in the baseplate. A plurality of plug holes is in the baseplate, wherein an end of each of the plug holes at a surface of the baseplate is chamfered and laser textured. A plurality of porous ceramic plugs is provided, wherein each porous ceramic plug of the plurality of porous ceramic plugs is in a plug hole of the plurality of plug holes. A plurality of ceramic plug coatings is on the sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings. A ceramic coating is on at least a first surface of the baseplate.

[0013] These and other features of the present disclosure will be described in more detail below in the detailed description and in conjunction with the following figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:

[0015] FIG. 1 is a schematic cross-sectional view of a baseplate of an electrostatic chuck (ESC) that may be used in an embodiment.

[0016] FIG. 2 is a schematic cross-sectional view of an enlarged part of a baseplate that may beused in the prior art.

[0017] FIGS. 3A-J are schematic cross-sectional views of an enlarged part of a baseplate that may be used in some embodiments.

[0018] FIG. 4 is a schematic cross-sectional view of part of an ESC that may be used in an embodiment.

[0019] FIG. 5 is a schematic view of a processing chamber that may be used in an embodiment.

[0020] In the drawings, like reference numerals are sometimes used to designate like structural elements. It should also be appreciated that the depictions in the figures are diagrammatic and not to scale.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present disclosure will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one skilled in the art, that the present disclosure may be practiced without some or all of these specific details. In other instances, well-known process steps and / or structures have not been described in detail in order to not unnecessarily obscure the present disclosure.

[0022] New semiconductor manufacturing processes require very high RF power plasmas. Increasing RF power causes an increase in RF currents and total voltages applied to the Electrostatic Chuck (ESC - wafer susceptor). At the same time, new plasma etch processes require significantly lower RF frequencies (e.g. 2 MHz, 400 kHz, or lower) than previously required. Low RF frequencies cause an additional increase in RF voltage applied across ESC ceramic. High voltage applied across ceramic may cause electrical discharge (arcing) between a wafer and a baseplate or ignition (light-up) of heat transfer gas (e.g. He) in the gas supplying holes. Arcing of the ESC usually causes catastrophic destruction of the part accompanied by wafer destruction, possible damage to other chamber components, and manufacturing process interruption. In the case of the heat transfer gas light-up, ESC destruction could be either catastrophic or could slowly develop affecting multiple wafers with semiconductor device damage, being detected only at much later steps of the manufacturing process. In both cases, ESC failure causes significant loss in wafer production and manufacturer’ s revenue.

[0023] Some ESCs comprise an electrically conductive baseplate below an electrically insulating ceramic plate. A bond layer may be used to attach the baseplate to the ceramic plate. Heat transfer passages may pass through the baseplate, the bond layer, and the ceramic plate.

[0024] For low-voltage applications, it is common to use straight holes in a ceramic plate with ceramic sleeves in baseplates opposing holes in the ceramic plate and preventing direct line of sight. For mid-low voltage applications, ceramic sleeves in baseplates are replaced with porous plugs providing a higher withstand voltage than ceramic sleeves. For mid-voltage applications, porous plugs are inserted in the ceramic plate, in addition to the sleeves in the baseplate.

[0025] An embodiment provides a solution for ESC arcing and He light-up problems by introducing plugs (made of ceramic material, e.g., alumina AI2O3 or aluminum nitride AIN), with small (diameter 0.1-100 micrometers) openings into He holes. The plugs compartmentalize the He hole volume into smaller micro-volumes that limit light-up probability. The probability is limited by reducing the number of charged particle collisions and preventing line of sight between a wafer and metal parts of the chuck below the top ceramic plate. Needed He flows through the holes for the wafer backside cooling to be maintained.

[0026] To facilitate understanding, FIG. 1 is a schematic cross-sectional view of a part of a baseplate 104 that is used in some embodiments. The baseplate 104 comprises an electrically conductive body with a plurality of gas passages 108 with a plurality of porous ceramic plugs 112 at the ends of the gas passages 108. A ceramic coating 116 is on a surface of a first side of the baseplate 104.

[0027] FIG. 2 is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in the prior art. The porous ceramic plug 112 has a porosity in the range of 10% to 80% by volume in order to allow gas to pass through the porous ceramic plug 112 while reducing arcing. In some embodiments, the porous ceramic plug 112 has a porosity in the range of 20% to 70%. In some embodiments, the porous ceramic plug 112 has a pore size in the range of 10 pm to 500 pm. A ceramic plug coating 204 is between the porous ceramic plug 112 and the baseplate 104. The ceramic plug coating 204 may be spray coated onto the sides of the porous ceramic plug 112. The ceramic plug coating 204 is less porous than the porous ceramic plug 112 so that the ceramic plug coating 204 is more resistant to arcing from the baseplate 104 than the porous ceramic plug 1 12. In some embodiments, the ceramic plug coating 204 has a porosity in the range of less than 5%. In some embodiments, the ceramic plug coating 204 has a porosity of less than 1%. In some embodiments, the ceramic plug coating 204 has a porosity of less than 0.5%. The ceramic plug coating 204 may not be between the baseplate 104 and the porous ceramic plug 112 near the first side of the baseplate 104, in order to allow gas to flow from a gas manifold 208 through the porous ceramic plug 112. The outer top edge of the porous ceramic plug 112 and the ceramic plug coating 204 are chamfered, as shown. The cornerof the baseplate 104 surrounding the hole for placement of the porous ceramic plug 112 is also chamfered. The chamfered corners allow for the spray deposition of the ceramic coating 116 to be angled in order to increase the adhesion of the ceramic coating 116. The chamfered corners also displace the top of the ceramic plug coating 204 from the top of the ceramic coating 116 in order to increase the adhesion of the ceramic coating 116. Most of the ceramic coating 116 has a thickness in the range of 100 pm to 550 pm. The thickness of the ceramic coating 116 in the chamfered corners is in the range of 500 pm to 1000 pm. The gas manifold 208 between the gas passage 108 and the porous ceramic plug 112 allows a larger surface of the porous ceramic plug 112 to be exposed to the temperature control gas.

[0028] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. The difference between the coefficient of thermal expansion (CTE) between the metal baseplate 104 and the porous ceramic plug 112 for the entire depth of the porous ceramic plug 112 below the ceramic coating 116 causes the stress on the ceramic coating 116. The stress on the ceramic coating 116 may cause cracking and / or delamination of the ceramic coating 116 resulting in heat transfer gas leakage, reducing the lifetime of the ESC. Reducing the stress on the ceramic coating 116 would increase the lifetime of the ESC.

[0029] FIG. 3 A is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. The ceramic plug coating 304 has a thicker flange portion 308 closer to the first end 320 of the porous ceramic plug 112 than to the second end 324 of the porous ceramic plug 112. The flange portion 308 causes the combination of the porous ceramic plug 112 and ceramic plug coating 304 to form a flange so that a diameter of the combination of the porous ceramic plug 112 and ceramic plug coating 304 at the second end 324 of the porous ceramic plug 112 is less than a diameter of the combination of the porous ceramic plug 112 and ceramic plug coating 304 between the first end 320 and the second end 324 of the porous ceramic plug 112. If the porous ceramic plug 112 was not chamfered, the flange portion 308 would extend to the first end 320 of the porous ceramic plug 112. The part of the porous ceramic plug 112 and the ceramic plug coating 304 that is under the thickest part of the ceramic coating 116 has a reduced depth D compared to the depth of the thickest part of the porous ceramic plug 112.

[0030] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. The flange portion 308 reduces the vertical depth D of the ceramic plug coating 304, which is located under the thickest parts of the ceramic coating 116. By reducing this vertical depth D, only the mismatch of the CTE of the baseplate 104 and the ceramic plug coating 304 for the depth D causes the stress at the thickest part of the ceramic coating 116. As a result, there is a reduced stress on the thickest part of the ceramic coating 116 compared to the prior art.

[0031] FIG. 3B is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. The porous ceramic plug 112 has a thicker flange portion 332 closer to the first end 320 of the porous ceramic plug 112 than to the second end 324 of the porous ceramic plug 112. The flange portion 332 causes the combination of the porous ceramic plug 112 and ceramic plug coating 304 to form a flange so that a diameter of the combination of the porous ceramic plug 112 and ceramic plug coating 304 at the second end 324 of the porous ceramic plug 112 is less than a diameter of the combination of the porous ceramic plug 112 and ceramic plug coating 304 between the first end 320 and the second end 324 of the porous ceramic plug 112. If the porous ceramic plug 112 was not chamfered, the flange portion 332 would extend to the first end 320 of the porous ceramic plug 112. The part of the porous ceramic plug 112 and the ceramic plug coating 304 that is under the thickest part of the ceramic coating 116 has a reduced depth D compared to the depth of the thickest part of the porous ceramic plug 112.

[0032] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. The flange portion 332 reduces the vertical depth D of the porous ceramic plug 112 and ceramic plug coating 304, which is located under the thickest parts of the ceramic coating 116. By reducing this vertical depth D, only the mismatch of the CTE of the baseplate 104 and the porous ceramic plug 112 for the depth D causes the stress on the ceramic coating 116 at the thickest part of the ceramic coating 116. As a result, there is a reduced stress on the thickest part of the ceramic coating 116 compared to the prior art.

[0033] FIG. 3C is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. The porous ceramicplug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. An adhesive coating 340 is placed around the ceramic plug coating 304 near the second end 324 of the porous ceramic plug 112. In some embodiments, the adhesive coating 340 is formed from an adhesive that is at least one of silicone bond and epoxy.

[0034] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. The adhesive causes the baseplate 104 and porous ceramic plug 112 to move together. The adhesive causes the porous ceramic plug 112 to be vertically retracted along with the baseplate 104. As a result, there is a reduced stress on the ceramic coating 116 compared to the prior art.

[0035] FIG. 3D is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112 including a ceramic plug coating 304, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. A CTE washer 348 (expansion washer) has a first side placed against the second end 324 of the porous ceramic plug 112 and ceramic plug coating 304. A second side of the CTE washer 348 opposite the first side is placed against the baseplate 104. As a result, the CTE washer 348 is between the second end 324 of the porous ceramic plug 112 and / or ceramic plug coating 304 and the baseplate 104. In some embodiments, the CTE washer 348 has a CTE that is greater than the CTE of the porous ceramic plug 112 and ceramic plug coating 304. In some embodiments, the CTE washer 348 has a CTE that is greater than the CTE of the baseplate 104, where the CTE of the baseplate 104 is greater than the CTE of the porous ceramic plug 112 and ceramic plug coating 304. This allows the greater CTE of the CTE washer 348 to compensate for the lower CTE of the porous ceramic plug 112 and ceramic plug coating 304. In some embodiments, the combination of the height (Hl) of the CTE washer 348, the height (H2) of the baseplate 104 adjacent to the CTE washer 348 and the ceramic plug coating 304, and the height (H3) of the porous ceramic plug 112 or ceramic plug coating 304 above the CTE washer 348 may be tuned so that the CTE of the baseplate 104 times the height (H2) of the baseplate 104 is approximately equal to the height (H3) of the porous ceramic plug 112 or ceramic plug coating 304 times the CTE of the porous ceramic plug 112 or ceramic plug coating 304 plus the height (Hl) of the CTE washer 348 times the CTE of the CTE washer 348. In some embodiments, the values are approximately equal when the values are within 10% of each other. In someembodiments, the sum of the height (Hl) of the CTE washer 348 and the height (H3) of the porous ceramic plug 112 or ceramic plug coating 304 above the CTE washer 348 is approximately equal to the height (H2) of the baseplate 104 adjacent the CTE washer 348 and the ceramic plug coating 304. In some embodiments, the CTE washer 348 comprises a polymer. In some embodiments, the polymer is a fluoropolymer, such as one or more of polytetrafluoroethylene (PTFE), such as Teflon®, perfluoroalkoxy alkane (PFA), polyetherimide, and polyether ether ketone (PEEK). In some embodiments, the CTE washer 348 is below the thickest part of the ceramic coating 116.

[0036] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. Since the CTE of the CTE washer 348 is greater than the CTE of the porous ceramic plug 112 the CTE difference is reduced. The CTE washer 348 may act as a cushion to reduce the vertical movement of the first end 320 of the porous ceramic plug 112 with respect to the first surface. As a result, there is a reduced stress on the ceramic coating 116 compared to the prior art.

[0037] FIG. 3E is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. In some embodiments, the chamfer of the porous ceramic plug 112 and the baseplate 104 is deeper. The deeper chamfer results in the thickness T of the ceramic coating 116 in the chamfer to be greater than 1200 pm. The thickness of the ceramic coating 116 at other locations on the surface of the baseplate 104 is in the range of 100 pm to 550 pm. In some embodiments, where the ceramic coating extends to each porous ceramic plug of the plurality of porous ceramic plugs or the ceramic plug coating 304, the ceramic coating has a thickness T of greater than 1200 pm, as shown in FIG. 3E.

[0038] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. By increasing the thickness of the ceramic coating 116 around the porous ceramic plug 112, the ceramic coating 116 is stronger around the porous ceramic plug 112. The stronger ceramic coating 116 reduces cracking increasing the lifetime of the baseplate 104.

[0039] FIG. 3F is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. In some embodiments, the porous ceramic plug 112 has a depth D in the range of 0.5 mm to 2.0 mm. In some embodiments, the porous ceramic plug 112 has a depth of less than half the depth of the porous ceramic plug used in the prior art. Since the depth of the porous ceramic plug 112 is reduced, thereis an increase in the electric field between the backside of the porous ceramic plug 1 12 and the baseplate 104, highlighting a potential arcing risk. The ceramic plug coating 304 extends to the backside of the porous ceramic plug 112 to prevent arcing between the backside of the porous ceramic plug 112 and the baseplate 104.

[0040] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112 causing stress on the ceramic coating 116. Since the thickness of the porous ceramic plug 112 is much less than half the thickness of the porous ceramic plug 112 used in the prior art, the stress on the ceramic coating 116 is reduced.

[0041] FIG. 3G is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 1 12, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104. A second end 324 of the porous ceramic plug 112 is placed a distance from the first end 320 and the first surface of the baseplate 104. Instead of the first end 320 of the porous ceramic plug 112 being chamfered, the first end 320 of the porous ceramic plug is funnel shaped, so that the first end 320 of the porous ceramic plug 112 has the widest diameter that tapers going towards the second end 324 of the porous ceramic plug 112. In some embodiments, at some point, the taper causes the porous ceramic plug 112 to reach a minimum diameter between the first end 320 and the second end 324, where the diameter remains constant to the second end 324 of the porous ceramic plug 1 12, as shown. The porous ceramic plug 112 and the ceramic plug coating 304 extend above the ceramic coating 116, in contrast to some of the other embodiments, where the porous ceramic plug 112 and ceramic plug coating 304 extend below the ceramic coating 116.

[0042] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112. Since the ceramic coating 116 is below the porous ceramic plug 112 and the ceramic plug coating 304, the porous ceramic plug 112 and the ceramic plug coating 304 do not provide stress on the ceramic coating 116.

[0043] FIG. 3H is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. An anodization layer 330 is between the first surface of the baseplate 104 and the ceramic coating 116. The anodization layer 330 is removed where the baseplate 104 is chamfered. The removal ofthe anodization layer 330 where the baseplate 104 is chamfered provides improved adhesion of the ceramic coating 116 to the baseplate 104 above the chamfer. This embodiment may be combined with other embodiments.

[0044] FIG. 31 is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 1 12, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. In this embodiment, the porous ceramic plug 112 is not chamfered. Instead, the porous ceramic plug 112 and the ceramic plug coating 304 form a cylinder shape. The ceramic coating 116 and an adhesive 362, such as epoxy, hold the porous ceramic plug 1 12 and ceramic plug coating 304 in place. In some embodiments, the porous ceramic plug 112 and ceramic plug coating 304 do not contact the baseplate 104. A space 364 is formed by a plug hole in the baseplate 104. The space is between the baseplate 104 and the porous ceramic plug 112.

[0045] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The cooling of the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112. Since ceramic coating 116 is not above the porous ceramic plug 112 and the ceramic plug coating 304, the porous ceramic plug 112 and the ceramic plug coating 304 do not provide stress on the ceramic coating 116. In addition, since the porous ceramic plug 112 and the ceramic plug coating 304 are not in direct contact with the baseplate 104, stress is further reduced.

[0046] FIG. 3 J is an enlarged schematic cross-sectional view of a part of the baseplate 104 and porous ceramic plug 112, shown as Region II, used in some embodiments. The porous ceramic plug 112 has a first end 320, adjacent to the first surface of the baseplate 104 and a second end 324 placed a distance from the first end 320 and the first surface of the baseplate 104. In this embodiment, the porous ceramic plug 112 is not chamfered. Instead the porous ceramic plug 112 forms a cylinder shape. The ceramic plug coating 304 has a larger diameter at the first end 320 than the second end 324 forming a counter sink to the chamfered hole in the baseplate 104. The porous ceramic plug 112 and the ceramic plug coating 304 are placed in the hole so that part of the ceramic plug coating 304 is over part of the ceramic coating 116. An adhesive 366, such as epoxy, may be placed between the ceramic plug coating 304 and part of the ceramic coating 116. In some embodiments, the porous ceramic plug 112 and ceramic plug coating 304 do not contact the baseplate 104 but instead have a space 368 between the baseplate 104 and the porous ceramic plug 112.

[0047] In operation, the baseplate 104 may be cooled to a temperature below 0° C. The coolingof the baseplate 104 causes the metal baseplate 104 to vertically shrink more than the porous ceramic plug 112. Since ceramic coating 116 is not above the porous ceramic plug 112 and the ceramic plug coating 304, the porous ceramic plug 112 and the ceramic plug coating 304 do not provide stress on the ceramic coating 116. In addition, since the porous ceramic plug 112 and the ceramic plug coating 304 are not in direct contact with the baseplate 104, stress is further reduced. The counter sink shape of the ceramic plug coating 304 allows for the ceramic plug coating 304 and porous ceramic plug 112 to be mounted into the baseplate 104 without providing contact with the baseplate 104. In some embodiments, the porous ceramic plug 112 forms the counter sink shape.

[0048] In some embodiments, the chamfered surface of the baseplate 104 is laser textured in order to increase the adhesion between the ceramic coating 116 and the chamfered surface of the baseplate 104. The laser texturing of the chamfered surface helps to prevent the ceramic coating 116 from breaking away from the chamfered surface of the baseplate.

[0049] In some embodiments, the baseplate 104 is bonded to a ceramic plate by a bond layer. FIG. 4 is a schematic cross-sectional view of a baseplate 104 with a porous ceramic plug 1 12 and a gas passage 108. A bond layer 404 bonds the baseplate 104 to a ceramic plate 408. In some embodiments, ceramic plate plugs 412 are in the ceramic plate 408 adjacent to heat transfer gas holes 416. In some embodiments, a plenum 420 is in the bond layer 404 between the porous ceramic plug 112 and a ceramic plate plug 412. In some embodiments, the ceramic plate plugs 412 are multilumen plugs. Some embodiments may provide different ceramic plate plugs 412.

[0050] FIG. 5 is a schematic view of an embodiment of a semiconductor processing chamber 500 that may be used for processing a semiconductor wafer. In one or more embodiments, a semiconductor processing chamber 500 comprises a gas distribution plate 506 providing a gas inlet and an electrostatic chuck (ESC) 508, within an etch chamber 549, enclosed by a chamber wall 552. Within the etch chamber 549, a wafer 503 is positioned over the ESC 508. The ESC 508 is a wafer support. An edge ring 509 surrounds the ESC 508. An ESC source 548 may provide a bias to the ESC 508. A gas source 510 is connected to the etch chamber 549 through the gas distribution plate 506. An ESC heat transfer gas source 550 is connected to the ESC 508.

[0051] A radio frequency (RF) source 530 provides RF power to a lower electrode, an upper outer electrode 516, and an upper inner electrode. In this embodiment, the ESC 508 is the lower electrode and the gas distribution plate 506 is the upper inner electrode. In an exemplary embodiment, 400 kilohertz (kHz), 60 megahertz (MHz), 2 MHz, 13.56 MHz, and / or 27 MHz power sources make up the RF source 530 and the ESC source 548. In this embodiment, onegenerator is provided for each frequency. In other embodiments, the generators may be separate RF sources, or separate RF generators may be connected to different electrodes. Other arrangements of RF sources and electrodes may be used in other embodiments. In other embodiments, an electrode may be an inductive coil.

[0052] A controller 535 is controllably connected to the RF source 530, the ESC source 548, an exhaust pump 520, and the gas source 510. A high flow liner 504 is a liner within the etch chamber 549. The high flow liner 504 in this embodiment is a C-shroud and confines gas from the gas source and has slots 502. The high flow liner 504 allows for a controlled flow of gas to pass from the gas source 510 to the exhaust pump 520.

[0053] During processing, heat transfer gas, such as, may be provided from the ESC heat transfer gas source 550 to the backside of the ESC 508 to provide heat transfer. The RF source 530 provides power to form a plasma. The plasma may cause arcing. The arcing could pass toward the heat transfer gas source and damage the ESC 508.

[0054] Although only a single porous ceramic plug with a ceramic plug coating and adhesive coating is shown, some embodiments use a plurality of porous ceramic plugs, where each porous ceramic plug has a ceramic plug coating of a plurality of ceramic plug coatings. In some embodiments, each of the porous ceramic plugs has a gas passage and may also have an expansion washer (CTE washer) or an adhesive coating.

[0055] While this disclosure has been described in terms of several embodiments, there are alterations, modifications, permutations, and various substitute equivalents, which fall within the scope of this disclosure. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present disclosure. It is therefore intended that the following appended claims be interpreted as including all such alterations, modifications, permutations, and various substitute equivalents as fall within the true spirit and scope of the present disclosure. As used herein, the phrase “A, B, or C” should be construed to mean a logical (“A OR B OR C”), using a non-exclusive logical “OR,” and should not be construed to mean ‘only one of A or B or C. Each step within a process may be an optional step and is not required. Different embodiments may have one or more steps removed or may provide steps in a different order. In addition, various embodiments may provide different steps simultaneously instead of sequentially.

Claims

CLAIMSWhat is claimed is:

1. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of porous ceramic plugs wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug; a plurality of expansion washers wherein each expansion washer of the plurality of expansion washers is between the second end of a porous ceramic plug of the plurality of porous ceramic plugs or ceramic plug coatings and the baseplate; and a ceramic coating on at least the first surface of the baseplate.

2. The electrostatic chuck, as recited in claim 1, wherein the plurality of expansion washers have a coefficient of thermal expansion (CTE) and the plurality of porous ceramic plugs have a CTE, wherein the CTE of the expansion washers is greater than the CTE of the plurality of porous ceramic plugs.

3. The electrostatic chuck, as recited in claim 1, wherein the plurality of expansion washers have a coefficient of thermal expansion (CTE) and the plurality of porous ceramic plugs have a CTE, and wherein the baseplate has a CTE, wherein the CTE of the expansion washers is greater than the CTE of the plurality of porous ceramic plugs and the CTE of the baseplate.

4. The electrostatic chuck, as recited in claim 1, further comprising: a bond layer on the first surface of the baseplate, wherein the baseplate is on a first side of the bond layer; and a ceramic plate on a second side of the bond layer.

5. The electrostatic chuck, as recited in claim 1, wherein the ceramic coating extends to each porous ceramic plug of the plurality of porous ceramic plugs.

6. The electrostatic chuck, as recited in claim 1, wherein the plurality of expansion washers comprise a polymer.

7. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of porous ceramic plugs wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug, wherein the combination of the porous ceramic plug and the ceramic plug coating form a flange so that a diameter of the combination of the porous ceramic plug and the ceramic plug coating at the second end of the porous ceramic plug is less than a diameter of the combination of the porous ceramic plug and ceramic plug coating between the first end and the second end of the porous ceramic plug; and a ceramic coating on at least the first surface of the baseplate.

8. The electrostatic chuck, as recited in claim 7, wherein a thickness of the ceramic plug coating at the second end of the porous ceramic plug is thinner than a thickness of the ceramic plug coating between the first end of the porous ceramic plug and the second end of the porous ceramic plug.

9. The electrostatic chuck, as recited in claim 7, wherein a diameter of the porous ceramic plug at the second end of the porous ceramic plug is less than a diameter of the porous ceramic plug between the first end of the porous ceramic plug and the second end of the porous ceramic Plug-10. The electrostatic chuck, as recited in claim 7, further comprising: a bond layer on the first surface of the baseplate, wherein the baseplate is on a first side of the bond layer; and a ceramic plate on a second side of the bond layer.

11. The electrostatic chuck, as recited in claim 7, wherein the ceramic coating extends to each porous ceramic plug of the plurality of porous ceramic plugs.

12. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of porous ceramic plugs wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug; a plurality of adhesive coatings, wherein each adhesive coating of the plurality of adhesive coatings is between a ceramic plug coating of the plurality of ceramic plug coatings and the baseplate; and a ceramic coating on at least the first surface of the baseplate.

13. The electrostatic chuck, as recited in claim 12, wherein each adhesive coating extends along a ceramic plug coating of the plurality of ceramic plug coatings adjacent to the second end of a porous ceramic plug of the plurality of porous ceramic plugs.

14. The electrostatic chuck, as recited in claim 12, further comprising: a bond layer on the first surface of the baseplate, wherein the baseplate is on a first side of the bond layer; and a ceramic plate on a second side of the bond layer.

15. The electrostatic chuck, as recited in claim 14, wherein the ceramic coating extends to each porous ceramic plug of the plurality of porous ceramic plugs.

16. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of porous ceramic plugs wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface;a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug; and a ceramic coating on at least the first surface of the baseplate, wherein part of the ceramic coating on the first surface of the baseplate has a thickness in a range of 100 pm to 550 pm and part of the ceramic coating on at least the first surface of the baseplate has a thickness of greater than 1200 pm.

17. The electrostatic chuck, as recited in claim 16, wherein the ceramic coating has a thickness of greater than 1200 pm above the ceramic plug coating.

18. The electrostatic chuck, as recited in claim 16, wherein the ceramic coating extends to each ceramic plug coating of the plurality of ceramic plug coatings, wherein where the ceramic coating extends to each ceramic plug coating of the plurality of ceramic plug coatings the ceramic coating has a thickness of greater than 1200 pm.

19. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of porous ceramic plugs wherein each porous ceramic plug of the plurality of porous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface, wherein each porous ceramic plug has a thickness in a range of 0.5 mm to 2 mm; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug; and a ceramic coating on at least the first surface of the baseplate.

20. The electrostatic chuck, as recited in claim 19, wherein each ceramic plug coating extends between the second end of a porous ceramic plug and the baseplate.

21. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of porous ceramic plugs wherein each porous ceramic plug of the plurality ofporous ceramic plugs extends from a first surface of the baseplate to a first end of a gas passage of the plurality of gas passages, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a first end adjacent to the first surface and a second end displaced from the first surface; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the ceramic plug coating has a porosity that is less than the porosity of the porous ceramic plug; and a ceramic coating on at least the first surface of the baseplate, wherein the ceramic coating extends between the plurality of ceramic plug coatings and the baseplate.

22. The electrostatic chuck, as recited in claim 21, wherein a diameter of the porous ceramic plug at the second end of the porous ceramic plug is less than a diameter of the porous ceramic plug at the first end of the porous ceramic plug.

23. The electrostatic chuck, as recited in claim 21, wherein the ceramic coating extends between the porous ceramic plugs and the baseplate.

24. The electrostatic chuck, as recited in claim 21, wherein the plurality of ceramic plug coatings extends to the first surface.

25. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of plug holes in the baseplate, wherein an end of each of the plug holes at a surface of the baseplate is chamfered; an anodization layer on a surface of the baseplate, wherein the anodization layer does not extend on the chamfer of the plug holes; a plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs is in a plug hole of the plurality of plug holes; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings; and a ceramic coating on at least a first surface of the baseplate, wherein the anodization layer is between the ceramic coating and the surface of the baseplate.

26. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body;a plurality of gas passages in the baseplate; a plurality of plug holes in the baseplate, wherein an end of each of the plug holes at a surface of the baseplate is chamfered; a plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs is in a plug hole of the plurality of plug holes; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings, wherein the plurality of porous ceramic plugs and the plurality of ceramic plug coatings do not contact the baseplate; and a ceramic coating on at least a first surface of the baseplate.

27. The electrostatic chuck, as recited in claim 26, further comprising an adhesive connecting the plurality of ceramic plug coatings to at least one of the baseplate and the ceramic coating.

28. The electrostatic chuck, as recited in claim 26, wherein each combination of porous ceramic plug and ceramic plug coating forms a counter sink shape.

29. An electrostatic chuck, comprising: a baseplate comprising an electrically conductive body; a plurality of gas passages in the baseplate; a plurality of plug holes in the baseplate, wherein an end of each of the plug holes at a surface of the baseplate is chamfered and laser textured; a plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs is in a plug hole of the plurality of plug holes; a plurality of ceramic plug coatings on sides of the plurality of porous ceramic plugs, wherein each porous ceramic plug of the plurality of porous ceramic plugs has a ceramic plug coating of the plurality of ceramic plug coatings; and a ceramic coating on at least a first surface of the baseplate.

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