Electrostatic chuck with porous plug

Abstract

Described herein is an electrostatic chuck and a method for forming the same. The electrostatic chuck includes a backside gas flow passage having a ceramic porous plug secured therein by a ceramic body of the chuck having a ceramic-to-ceramic body. In one example, the ceramic porous plug is sintered with the ceramic body.

Description

[Technical field]

[0001] TECHNICAL FIELD

[0001] Implementations described herein relate generally to substrate support assemblies, and more particularly to substrate support assemblies having a bonded porous plug and methods of bonding a porous plug to a substrate support assembly. [Background technology]

[0002] Substrate support assemblies are widely used to support substrates in semiconductor processing systems during processing. One particular type of substrate support assembly includes a ceramic electrostatic chuck mounted to a cooled base. Electrostatic chucks generally hold a substrate in a stationary position during processing. Electrostatic chucks include one or more embedded electrodes within a ceramic body. When a potential is applied between the electrodes and a substrate disposed on the ceramic body, an electrostatic force is generated to hold the substrate against the support surface of the ceramic body. The generated force may be a capacitive effect due to a potential difference between the substrate and the electrodes, or a Johnsen-Rahbek effect in the case of ceramic bodies constructed of semiconducting materials with relatively low resistivity that allow charges within the ceramic body to migrate to a surface near the substrate. Electrostatic chucks utilizing capacitance and Johnsen-Rahbek attraction are commercially available from a number of sources.

[0003] To control the substrate temperature during processing, a backside gas is provided to the support surface of the ceramic body below the substrate through gas passages formed in the ceramic body. The backside gas fills the gap area between the ceramic body and the substrate, thus providing a heat transfer medium that enhances the rate of heat transfer between the substrate and the substrate support. To prevent the backside gas flowing through the gas passages from igniting within the ceramic body, a porous ceramic plug is positioned in the gas passage. The porous plug is secured to the ceramic body using an adhesive.

[0004] However, the insertion of the plug into the ceramic body is unpredictable. Variations in the quality of the plug insertion can erode the adhesive that holds the plug to the ceramic body during the life of the electrostatic chuck, leading to premature arcing failures and secondary particle contamination of the substrate. This variability is exacerbated by the manual application of the adhesive to secure the plug. Furthermore, exposure to high temperatures can further weaken the adhesion between the ceramic body, the porous plug, and / or the substrate due to plasma, CTE mismatch, and friction. Once the adhesive fails, contamination of the substrate is inevitable, as material eroded from the adhesive layer becomes a process contaminant, causing defects and reducing product yield. Furthermore, once the bond between the porous plug and the ceramic body fails, the bonding layer that secures the electrostatic chuck to the cooling base can be attacked by process gases and other gases, dramatically shortening the life of the electrostatic chuck.

[0005] Therefore, there is a need for an improved electrostatic chuck and method of manufacturing the same. Summary of the Invention

[0006]

[0006] Described herein is an electrostatic chuck and a method for forming the same. The electrostatic chuck includes a ceramic body having a backside gas flow passage to which a ceramic porous plug is secured using a ceramic-to-ceramic bond. In one example, the ceramic porous plug is sintered with the ceramic body. Although sintering the ceramic porous plug with the ceramic body is described as forming an electrostatic chuck as a primary example, the method described herein may also be performed to bond the ceramic porous plug with a ceramic structure other than an electrostatic chuck to form a single fired ceramic body having an integral sintered porous plug disposed within the flow passage of the ceramic structure.

[0007] In another example, an electrostatic chuck includes a ceramic body and a ceramic porous plug disposed in a gas flow passage of the ceramic body. The ceramic body has a substrate support surface and a bottom surface. The ceramic body includes an electrode and a gas flow passage extending between the substrate support surface and the bottom surface. The ceramic porous plug is secured to the gas flow passage by a ceramic-to-ceramic bond.

[0008] In another embodiment, an electrostatic chuck suitable for use in a semiconductor processing chamber is provided. The electrostatic chuck includes a ceramic body and a ceramic porous plug. The ceramic body includes a substrate support surface and a bottom surface, an electrode, and a gas passage extending between the substrate support surface and the bottom surface. The ceramic porous plug is disposed within the gas passage and is sintered to the ceramic body. A temperature controlled base is secured to the bottom surface of the ceramic body by an adhesive layer. The temperature controlled base includes gas feed holes aligned with the gas passages formed in the ceramic body. The aligned gas feed holes and gas passages are configured to flow a backside gas to the support surface of the ceramic body.

[0009] In yet another example, a method for manufacturing an electrostatic chuck is provided that includes at least partially disposing a ceramic porous plug within a hole formed in a ceramic structure, the hole being configured to provide a fluid passageway; and sintering the ceramic structure and the ceramic porous plug to form a ceramic-to-ceramic bond therebetween.

[0010] In one embodiment, the ceramic structure is the ceramic body of an electrostatic chuck. In other examples, the ceramic structure may be a structure such as a plate, a shield, a liner, a body, a filter, a vessel, or a gas distribution plate.

[0011]

[0011] In order to allow the above features of the present disclosure to be understood in detail, a more detailed description of the above briefly summarized implementations can be obtained by referring to the implementations. Some embodiments are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings show only typical implementations of this disclosure, since the present disclosure may admit of other equally effective implementations, and therefore should not be considered as limiting the scope of the present invention. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a processing chamber including a substrate support assembly having a co-sintered porous plug in accordance with one or more implementations of the present disclosure. [Diagram 2]

[0013] FIG. 1 is a schematic cross-sectional view of a substrate support assembly having a porous plug co-sintered with a ceramic body of an electrostatic chuck in accordance with one or more implementations of the present disclosure. [Diagram 3] FIG. 3 is a partial cross-sectional exploded view of the electrostatic chuck of FIG. 2 in accordance with one or more implementations of the present disclosure. [Figure 4]

[0015] FIG. 1 is a cross-sectional view of a portion of an electrostatic chuck sintered with a porous plug in accordance with one or more implementations of the present disclosure. [Diagram 5]

[0016] FIG. 1 is a cross-sectional view of a portion of an electrostatic chuck sintered with a porous plug in accordance with one or more implementations of the present disclosure. [Figure 6]

[0017] A cross-sectional view of a portion of a substrate support assembly illustrating a sintered electrostatic chuck with a porous plug mated to a temperature-controlled base of the substrate support assembly in accordance with one or more implementations of the present disclosure. [Figure 7]

[0018] FIG. 1 is a flow diagram of a method for forming an electrostatic chuck having a co-sintered porous plug in accordance with one or more implementations of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013]

[0019] For ease of understanding, wherever possible, identical reference numbers have been used to designate identical elements that are common to multiple figures. It is envisioned that elements and features of one implementation may be beneficially incorporated in other implementations without further recitation.

[0014]

[0020] Many of the details, scales, dimensions, angles, and other features shown in the drawings are merely illustrative of particular implementations. Thus, other implementations may have other details, components, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. Moreover, further implementations of the present disclosure may be practiced without some of the details described below.

[0015]

[0021] The following disclosure describes an electrostatic chuck having a ceramic body to which a ceramic porous plug is secured by a ceramic-to-ceramic bond. Also described is a method for forming the same. The ceramic-to-ceramic bond between the ceramic body and the ceramic porous plug eliminates the need for a bonding material to secure the ceramic porous plug to the backside gas flow passage of the ceramic body. This results in reduced contamination of substrates processed on the electrostatic chuck and reduced failure modes of the chuck, thereby extending the useful life of the chuck. Thus, the ceramic-to-ceramic bond of the ceramic porous plug to the ceramic body provides a robust and reliable electrostatic chuck with significantly improved performance uniformity between chucks. These advantages result in a significant reduction in the cost of ownership, as well as synergistic improvements in production yield and capacity due to the reduced particulate contamination and increased mean service intervals associated with the use of electrostatic chucks.

[0016]

[0022] 1, a schematic diagram of a processing chamber 100 including a substrate support assembly 110 is illustrated in accordance with one or more implementations of the present disclosure. The substrate support assembly 110 includes an electrostatic chuck 112 disposed on a temperature controlled base 114. The electrostatic chuck 112 has a ceramic porous plug secured to the backside gas flow passage using ceramic-to-ceramic bonding as described below, which provides the advantages discussed above. As additionally described herein, the ceramic porous plug may alternatively be secured to the fluid passage of other types of ceramic structures using ceramic-to-ceramic bonding.

[0017]

[0023] The processing chamber 100 includes a chamber body 102 that defines a processing space 104. A substrate support assembly 110 is positioned within the processing space 104. The chamber body 102 includes a ceiling 106, a bottom wall 107, and one or more chamber walls 108. The ceiling 106 may be composed of a dielectric material.

[0018]

[0024] The substrate support assembly 110 is generally supported above the bottom wall 107 of the processing chamber 100 by a shaft 116 coupled to a temperature control base 114. The substrate support assembly 110 is clipped to the shaft 116 such that the substrate support assembly 110 can be removed from the shaft 116, refurbished, and clipped back to the shaft 116. The shaft 116 is sealed to the temperature control base 114 and isolates the various conduits and electrical leads disposed therein from the processing environment within the processing chamber 100. Alternatively, the electrostatic chuck 112 and the temperature control base 114 may be disposed on an insulating plate that is attached to a ground plate or chassis. Additionally, the ground plate may be attached to one or more of the ceiling 106, the bottom wall 107, and one or more chamber walls 108.

[0019]

[0025] The electrostatic chuck 112 is generally circular, but may accommodate non-circular substrates including other shapes. For example, the electrostatic chuck 112 may include a square or rectangular substrate when used to process display glass, such as glass for flat panel displays. The electrostatic chuck 112 includes a substrate support surface 120 for supporting a substrate, such as a substrate 122, such as a semiconductor substrate. The temperature of the substrate 122 is controlled by controlling the temperature of the electrostatic chuck 112. The temperature control base 114 includes heating and / or cooling elements that are utilized to heat and / or cool the electrostatic chuck 112 secured to an upper surface of the temperature control base 114. In one example, the temperature control base 114 may include a resistive heater and / or a conduit for flowing a heat transfer fluid such that heat may be transferred to or away from the electrostatic chuck 112, thereby controlling the temperature of the electrostatic chuck 112 along with the substrate 122 positioned thereon. To facilitate heat transfer between the electrostatic chuck 112 and the substrate 122, a backside gas (e.g., helium, nitrogen, argon, or other gas) may be provided by a gas source 124 to a gap space defined between the substrate 122 and the substrate support surface 120 of the electrostatic chuck 112. The backside gas provides a heat transfer medium that facilitates heat transfer between the substrate 122 and the substrate support assembly 110, thereby enhancing temperature control of the substrate 122 during processing, cleaning, or otherwise desired.

[0020]

[0026] The electrostatic chuck 112 may include one or more heaters. For example, the heaters may be resistive heaters, etc. The electrostatic chuck 112 includes one or more electrodes, which may be coupled to a power source 125. At least one of the electrodes of the electrostatic chuck 112 is utilized to generate an electrostatic force that secures the substrate 122 to the substrate support surface 120 of the electrostatic chuck 112. Any other electrodes disposed within the electrostatic chuck 112 may be utilized for plasma control, cleaning, or other purposes.

[0021]

[0027] The processing chamber 100 further includes at least an inductive coil antenna segment 130A and a conductive coil antenna segment 130B, both positioned outside the ceiling 106. The inductive coil antenna segment 130A and the conductive coil antenna segment 130B are each coupled to a radio frequency (RF) source 132 that generates an RF signal. The RF source 132 is coupled to the inductive coil antenna segment 130A and the conductive coil antenna segment 130B via a matching network 134. The substrate support assembly 110 is also coupled to an RF source 136 that generates an RF signal. The RF source 136 is coupled to the substrate support assembly 110 via a matching network 138. One or more of the chamber walls 108 are electrically conductive and may be connected to an electrical ground 140.

[0022]

[0028] The pressure within the process space 104 of the process chamber 100 is controlled using a throttle valve 142 between the process chamber 100 and a vacuum pump 144. The temperature of the surface of one or more chamber walls 108 is controlled using a liquid-containing conduit (not shown) located in the one or more chamber walls 108 of the process chamber 100.

[0023]

[0029] A system controller 206 may be coupled to various components of the processing chamber 100 to facilitate control of substrate processing operations. The system controller 150 includes a memory 152, a central processing unit (CPU) 154, and support circuits (or I / O) 156. Software instructions and data for instructing the CPU may be coded and stored in the memory. The system controller 150 may communicate with one or more components of the processing chamber 100, for example, via a system bus. A program (or computer instructions) readable by the system controller 150 determines which tasks are executable on the substrate. In some embodiments, the program is software readable by the system controller 150. Although a single system controller 150 is shown, it should be understood that multiple system controllers may be used in the embodiments described herein.

[0024]

[0030] In one example of operation, the substrate 122 is placed on the substrate support surface 120 of the substrate support assembly 110. A backside gas is provided between the substrate 122 and the substrate support surface 120 of the electrostatic chuck 112 to enhance temperature control of the substrate 122 during processing. Gaseous components are supplied to the processing chamber 100 from the gas panel 160 through the inlet port 162 to form a gaseous mixture in the processing space 104 of the processing chamber 100. The gaseous mixture in the processing space 104 is ignited into a plasma in the processing chamber 100 by applying RF power from the RF sources 132, 136 to the inductive coil antenna segment 130A, the conductive coil antenna segment 130B, and the substrate support assembly 110, respectively. Furthermore, chemically reactive ions are emitted from the plasma and bombard the substrate 122, thereby removing exposed material from the substrate surface.

[0025]

[0031] Although the exemplary processing chamber 100 detailed above is illustrated as an inductively coupled etch processing chamber, the processing chamber 100 may be configured as another type of etch processing chamber, a chemical vapor deposition chamber, a physical vapor deposition chamber, an ion implantation chamber, or other semiconductor, flat panel, or like processing chamber where the use of ceramic-to-ceramic bonding of porous plugs within a ceramic body is desired.

[0026]

[0032] 2 is a partial cross-sectional view of a substrate support assembly 110 having a ceramic porous plug 202 secured to a ceramic body 204 of an electrostatic chuck 112 without the use of an adhesive. The ceramic body 204 of the electrostatic chuck 112 is fabricated from a ceramic material, such as alumina, aluminum nitride, or other suitable material. For example, the ceramic body 204 of the electrostatic chuck 112 may be fabricated from a low resistivity ceramic material, such as ... 9 ~Approx. 1×E 11The ceramic body 204 may be fabricated from a material having a resistivity between 1×E Ω·cm. Examples of low resistivity materials include ceramics such as alumina doped with titanium oxide or chromium oxide, doped aluminum oxide, doped boron nitride, and the like. Other materials of comparable resistivity, such as aluminum nitride, may also be used. Such ceramic materials having relatively low resistivity generally facilitate Johnsen-Rahbek attraction between the substrate and the electrostatic chuck 112 when power is applied to the chuck electrode 218 embedded within the ceramic body 204. Alternatively, the ... 11 The ceramic body 204 of the electrostatic chuck 112 may include a ceramic material having a resistivity of Ω·cm or higher. Additionally, the ceramic body 204 of the electrostatic chuck 112 may be fabricated from aluminum oxide, which has a high resistivity and may be used in the Coulombic mode.

[0027]

[0033] The ceramic body 204 is formed from green sheets or layers that are sintered together to form a solid continuous body of ceramic. In the example depicted in FIG. 2, dashed lines indicate three layers 212, 214, 216 that are laminated together prior to sintering. The number of layers is merely for illustration, as the ceramic body 204 may be formed from any number of layers desired. The chuck electrode 218 (and any other electrodes and heaters present) is disposed, for example, between layers 214, 216 prior to sintering, such that after sintering, the chuck electrode 218 is embedded in the solid mass of ceramic that comprises the ceramic body 204.

[0028]

[0034] The chuck electrode 218 is fabricated from a conductive material such as copper, graphite, tungsten, molybdenum, etc. Various implementations of the electrode structure include, but are not limited to, a pair of coplanar D-shaped electrodes, coplanar interdigitated electrodes, multiple coaxial annular electrodes, a single circular electrode, or other structures. The chuck electrode 218 is coupled to a power source 125 by a feedthrough 220 disposed on the substrate support assembly 110. The power source 125 may drive the electrode 218 with a positive or negative voltage. For example, the power source 125 may drive the electrode 218 with a voltage of about -1000 volts or about 2500 volts. Alternatively, other negative or positive voltages may be utilized.

[0029]

[0035] In some examples, each of the layers 212, 214, 216 may be composed of the same type of ceramic material. For example, all of the layers 212, 214, 216 may be formed from ceramic powders having the same powder size, which generally results in a uniform grain size throughout the layers 212, 214, 216 after sintering. In another example, one or more of the layers 212, 214, 216 may be composed of different types of ceramic materials. For example, the top layer 216 may be formed from ceramic powders having one size of powder, while the bottom layer 212 may be formed from ceramic powders having a different size of powder, which generally results in different grain sizes in different regions (i.e., formed from the layers 212, 214, 216) after sintering.

[0030]

[0036] The ceramic body 204 also includes a number of backside gas passages 206. The backside gas passages 206 are open to the substrate support surface 120 of the electrostatic chuck 112 so that a backside gas can be provided between the substrate and the electrostatic chuck to enhance heat transfer, as described above. One or more of the backside gas passages 206 forming each backside gas channel through the electrostatic chuck 112 includes a hole 208 formed in the bottom surface 238 of the ceramic body 204. The hole 208 is sized to receive at least a portion of the ceramic porous plug 202, such that a backside gas delivery channel is formed through the passages 206, the plug 202, and the hole 208 to provide a backside gas to the substrate support surface 120 in a region below the substrate to enhance heat transfer between the electrostatic chuck 112 and the substrate. The transition between the passages 206 and the hole 208 forms a step 210 to ensure that the ceramic porous plug 202 is positioned within the hole 208. The hole 208 and cross section of the ceramic plug 202 are typically circular, although any complementary shape may be utilized. For example, the ceramic plug 202 may have a square profile that matches the square mating shape of the hole 208. Additionally, although only one backside gas supply channel is illustrated in FIG. 2, it is envisioned that multiple similarly configured backside gas supply channels are distributed across the substrate support surface 120 of the electrostatic chuck 112.

[0031]

[0037] The ceramic porous plug 202 is secured within the hole 208 by a ceramic-to-ceramic bond. That is, the outer diameter of the ceramic porous plug 202 is bonded directly to the inner diameter of the hole 208 formed in the ceramic body 204 using a sintering process without the use of adhesives. For example, a ceramic-to-ceramic bond created by a sintering process fuses the ceramic material of the ceramic porous plug 202 with the ceramic material of the ceramic body 204 to form a singular solid mass using a combination of pressure and heat without melting the materials of the plug 202 and body 204.

[0032]

[0038] The porous plug 202 is made from a ceramic material, such as alumina, aluminum nitride, or other suitable material. The ceramic porous plug 202 can be made from the same type of material used to make the ceramic body 204. The ceramic porous plug 202 can be formed entirely from ceramic powders having the same powder size, which generally results in a uniform grain size throughout the plug 202. In some examples, the ceramic porous plug 202 can be formed using different types of ceramic materials in different regions of the plug 202. For example, the ceramic porous plug 202 can include an upper region 222 adjacent the step 210 of the hole 208 and a lower region 224 adjacent the bottom surface 238 of the ceramic body 204. The powder size can be different in each of the regions 222, 224, resulting in different grain sizes of the ceramic material in each of the regions 222, 224. The powder size in each of the regions 222, 224 may be the same or different from the powder size utilized in one or more of the layers 212, 214, 216 forming the ceramic body 204. As a result, the grain size in the regions 222, 224 of one or both of the plugs 202 is different from the grain size in one or more of the layers 212, 214, 216 of the ceramic body 204. In one example, the grain size in the regions 222, 224 of one or both of the plugs 202 is larger than the grain size in at least one or more or all of the layers 212, 214, 216 of the ceramic body 204.

[0033]

[0039] The holes 208 formed in the ceramic body 204 align with the gas supply holes 230 formed through the temperature control base 114. The gas supply holes 230 are coupled to a gas source 124 that provides a backside gas, such as helium, nitrogen, argon, or other suitable gas.

[0034]

[0040] An adhesive layer 226 that bonds the electrostatic chuck 112 to the temperature controlled base 114 includes gaps 228 that allow backside gas to flow from gas supply holes 230 formed in the base 114 to the channels 206 formed in the chuck 112. The adhesive layer 226 can be an optically clear adhesive, such as an acrylic or silicone adhesive, an epoxy, a neoprene adhesive, a clear acrylic adhesive, or other suitable adhesive material.

[0035]

[0041] The temperature control base 114 is generally fabricated from a metallic material, such as stainless steel, aluminum, an aluminum alloy, or other suitable material. Additionally, the temperature control base 114 includes one or more heat transfer elements 232, such as a resistive heater, a thermoelectric device, or a conduit for flowing a heat transfer fluid. In the example shown in Figure 2, the heat transfer element 232 is in the form of a channel for flowing a heat transfer fluid provided from a heat transfer fluid source 236. The heat transfer fluid source 236 is coupled to the channel (e.g., the heat transfer element 232) by a conduit 234.

[0036]

[0042] Continuing with the description of the ceramic porous plug 202, the porous plug 202 may have an open pore structure, meaning that the pores in the porous structure are interconnected to allow fluid to flow through the porous plug 202. In some implementations, more than half of the cells of the open pore structure are interconnected. For example, the porous plug 202 provides a path for pressurized gas to flow from the gas feed holes 230 formed through the temperature control base 114 to the substrate support surface 120 of the electrostatic chuck 112. The passages and / or pores that allow gas to flow through the ceramic porous plug 202 are sized to reduce the probability of plasma ignition in the bond gap 228 defined between the electrostatic chuck 112 and the temperature control base 114, as compared to a design that does not include the porous plug 202. In one example, the ceramic porous plug 202 may have a porosity of about 30 percent to about 80 percent. Alternatively, the porous plug may have a porosity of less than 30% or more than 80%.

[0037]

[0043] The porous plug 202 may have any suitable shape. In some implementations, the porous plug 202 has a cylindrical shape. Other suitable shapes include a T-shape, a tapered shape, a rectangular shape, etc.

[0038]

[0044] As discussed above, the ceramic-to-ceramic bond between the porous plug 202 and the ceramic body 204 allows for the plug 202 to be secured to the ceramic body 204 without the use of adhesives. Advantageously, the plug 202 co-sintered with the ceramic body 204 forms a unique structure that is highly resistant to erosion from process gases, has a significantly longer service life, and is much less likely to shed particles that can become process contaminants and reduce production yields, as compared to conventional electrostatic chucks that utilize adhesives to secure the porous plug.

[0039]

[0045] 3 is a partial cross-sectional exploded view of a portion of the electrostatic chuck 112 of FIG. 2 in accordance with one or more implementations of the present disclosure 112. In the exploded view of FIG. 3, the ceramic porous plug 202 is shown prior to being inserted into the hole 208 formed in the bottom surface 238 of the ceramic body 204 of the electrostatic chuck 112. In one example, the ceramic porous plug 202 may be fully formed and sintered to form a ceramic solid body. After insertion, the ceramic porous plug 202 and the ceramic body 204 are sintered together to form a ceramic solid body.

[0040]

[0046] In another example, the ceramic porous plug 202 may be partially sintered prior to insertion into the hole 208 of the ceramic body 204 of the electrostatic chuck 112. After insertion, the ceramic porous plug 202 and the ceramic body 204 are sintered together to form a ceramic solid body.

[0041]

[0047] In yet another example, the ceramic porous plug 202 may be in a completely green state prior to insertion into the hole 208 of the ceramic body 204 of the electrostatic chuck 112. After insertion, the ceramic porous plug 202 and the ceramic body 204 are sintered together to form a ceramic solid body.

[0042]

[0048] 3, the ceramic porous plug 202 includes a top surface 302, a bottom surface 306, and a sidewall 304. The sidewall 304 may be an outer diameter of the ceramic porous plug 202. In implementations in which the cross-sectional profile of the ceramic porous plug 202 is not circular, the one or more sidewalls 304 simply define an outer periphery of the plug 202 connecting the top surface 302 and the bottom surface 306 of the plug 202, and mate with and are sintered together with a sidewall of a complementarily shaped hole 208 formed in the ceramic body 204.

[0043]

[0049] 4 is a cross-sectional view of a portion of an electrostatic chuck 112 sintered with a ceramic porous plug 202 in accordance with one or more implementations of the present disclosure. In the example shown in FIG. 4, the bottom surface 306 of the ceramic porous plug 202 is substantially coplanar with the bottom surface 238 of the ceramic body 204. The bottom surface 306 of the ceramic porous plug 202 may be made coplanar with the bottom surface 238 of the ceramic body 204 by any suitable technique. In one example, the bottom surface 306 of the ceramic porous plug 202 is polished coplanar with the bottom surface 238 of the ceramic body 204.

[0044]

[0050] 5 is a cross-sectional view of a portion of a ceramic body 204 co-sintered with a ceramic porous plug 202 according to another implementation of the present disclosure. In the example shown in FIG. 5, the bottom surface 306 of the ceramic porous plug 202 is recessed from the bottom surface 238 of the ceramic body 204. The bottom surface 306 of the ceramic porous plug 202 may be recessed from the bottom surface 238 of the ceramic body 204 by any suitable technique. In one example, the bottom surface 306 of the ceramic porous plug 202 is machined below the bottom surface 238 of the ceramic body 204. In another example, the height of the ceramic porous plug 202 is less than the depth of the holes 208 formed in the ceramic body 204.

[0045]

[0051] 6 is a cross-sectional view of a portion of the substrate support assembly 110 illustrating an electrostatic chuck 112 sintered with a ceramic porous plug 202 according to another implementation of the present disclosure. In FIG. 6, the ceramic porous plug 202 protrudes from the bottom surface 238 of the ceramic body 204. For example, the ceramic porous plug 202 may have a height that is greater than the depth of the hole 208 formed in the ceramic body 204.

[0046]

[0052] 6, the bottom surface 306 of the ceramic porous plug 202 protrudes from the bottom surface 238 of the ceramic body 204 a sufficient distance to shield the adhesive layer 226. In this manner, the adhesive layer 226 is shielded (i.e., substantially prevented) from exposure to process gases or other gases that may pass through the porous plug 202. In one example, the bottom surface 306 of the ceramic porous plug 202 protrudes a distance from the bottom surface 238 of the ceramic body 204 such that the bottom surface 306 is substantially coplanar with or extends below the top surface 240 of the temperature control base 114.

[0047]

[0053] 6, the bottom surface 306 of the ceramic porous plug 202 extends into a recess 602 in the top surface 240 of the temperature controlled base 114. The gas feed holes 230 terminate at the recess 602 such that backside gas can easily flow through the gas feed holes 230, through the plug 202, and into the backside gas channel 206. Because the ceramic porous plug 202 extends into the recess 602 through a gap 228 formed in the bonding layer 226, the ceramic porous plug 202 effectively shields the bonding layer 226 from gas flowing between the gas feed holes 230 and the backside gas channel 206.

[0048]

[0054] 7 is a flow diagram of a method 700 for forming a sintered ceramic structure with a porous plug 202 in accordance with one or more implementations 202 of the present disclosure. Although the method 700 describes sintering the ceramic porous plug 202 with a ceramic structure to form a single fired ceramic body, the method 700 is particularly advantageous for forming an electrostatic chuck 112. The method 700 may be performed to join the ceramic porous plug 202 with a ceramic structure other than an electrostatic chuck to form a single fired ceramic body having a porous plug integrated with flow channels within the ceramic structure. Some non-limiting examples of ceramic structures include a plate, shield, liner, body, filter, vessel, or gas distribution plate, etc.

[0049]

[0055] The method 700 begins at operation 702 by placing a ceramic porous plug 202 at least partially into a hole 208 formed in a ceramic structure. In one example, the hole 208 is configured to be a fluid passageway in the fired ceramic structure.

[0050]

[0056] A particular implementation of the method 700 utilized to form the electrostatic chuck 112 includes disposing the ceramic porous plug 202 at least partially within a hole 208 formed in a green sheet of ceramic material. In one example, the hole 208 is configured to be a backside gas flow passage for the electrostatic chuck 112. In one example, the hole 208 is configured to be a flow passage in another type of ceramic substrate.

[0051]

[0057] The ceramic porous plug 202 is fully sintered before being placed within the hole 208 of the ceramic body 204 in operation 702. Alternatively, the ceramic porous plug 202 may be partially sintered or not fully sintered before being placed within the hole 208 in operation 702.

[0052]

[0058] Similarly, the ceramic body 204 may be partially sintered or not fully sintered prior to receiving the ceramic porous plug 202 in the hole 208 in operation 702. Alternatively, the ceramic porous plug 202 may be fully sintered prior to receiving the ceramic porous plug 202 in the hole 208 in operation 702. In some examples, in operation 702, an unsintered ceramic porous plug 202 is placed in the hole 208 of an unsintered, partially sintered, or fully sintered ceramic body 204. In some examples, in operation 702, a partially sintered ceramic porous plug 202 is placed in the hole 208 of an unsintered, partially sintered, or fully sintered ceramic body 204. In yet other examples, in operation 702, a fully sintered ceramic porous plug 202 is placed in the hole 208 of an unsintered or partially sintered ceramic body 204.

[0053]

[0059] In operation 702, the ceramic porous plug 202 may be disposed completely within the hole 208 such that the bottom surface 306 of the ceramic porous plug 202 is flush with or recessed from the bottom surface 238 of the ceramic body 204. Alternatively, the ceramic porous plug 202 may be disposed within the hole 208 such that the bottom surface 306 of the ceramic porous plug 202 protrudes from the bottom surface 238 of the ceramic body 204. In some examples, the bottom surface 306 of the ceramic porous plug 202 may protrude sufficiently such that the ceramic porous plug 202 mates with a recess 602 formed in the bottom surface 238 of the ceramic body 204.

[0054]

[0060] One or both of the ceramic porous plug 202 and the ceramic body 204 may comprise different types of ceramic materials. For example, one or both of the ceramic porous plug 202 and the ceramic body 204 may be made of different size powders and / or different types of ceramic materials, as described above.

[0055]

[0061] In operation 704 of method 700, the ceramic material of the porous plug 202 and the ceramic structure are sintered together to form a ceramic-to-ceramic bond therebetween. In operation 704, the ceramic material of the porous plug 202 and the ceramic structure are sintered together to form a continuous solid of fired ceramic.

[0056]

[0062] The operation 704 utilized to form the electrostatic chuck 112 includes sintering together the ceramic material of the porous plug 202 and the ceramic body 204 to form a ceramic-to-ceramic bond therebetween. In operation 704, the ceramic material of the porous plug 202 and the ceramic body 204 are sintered together to form a ceramic continuous solid.

[0057]

[0063] An electrostatic chuck and method for forming the same are described above that utilizes ceramic-to-ceramic bonding to eliminate the need for adhesives to secure a porous plug to the ceramic body of the electrostatic chuck. The porous plug and body of the electrostatic chuck are unique ceramic bodies, which reduces chuck failure modes and extends the useful life of the chuck. Furthermore, the absence of adhesives to secure the plug to the chuck body significantly reduces the amount of contaminants compared to conventional designs, advantageously improving production yields. Thus, ceramic-to-ceramic bonding of the ceramic porous plug to the ceramic body results in a robust and reliable electrostatic chuck with significantly improved performance uniformity from chuck to chuck. These advantages result in a significant reduction in cost of ownership, as well as synergistic improvements in production yield and capacity due to the reduced particulate contamination and increased mean service intervals associated with the use of electrostatic chucks.

[0058]

[0064] Although the above description is directed to an embodiment of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, the scope of the present disclosure being determined by the following claims. As is apparent from the above summary and specific embodiments, although forms of the present disclosure have been illustrated and described, various modifications may be made without departing from the essence and scope of the present disclosure. Therefore, it is not intended that the present disclosure be limited by the forms of the present disclosure illustrated and described.

Claims

1. 1. An electrostatic chuck comprising: a ceramic body having a substrate support surface and a bottom surface, an electrode, and a gas passage extending between the substrate support surface and the bottom surface; a ceramic porous plug secured in the gas flow passage by a ceramic-to-ceramic bond; 1. An electrostatic chuck comprising:

2. 10. The electrostatic chuck of claim 1, wherein said ceramic porous plug is sintered to said ceramic body.

3. 2. The electrostatic chuck of claim 1, wherein the ceramic porous plug has a grain size similar to a grain size of the portion of the ceramic body that contacts the ceramic porous plug.

4. 2. The electrostatic chuck of claim 1, wherein the ceramic porous plug has a grain size that is different from a grain size of a portion of the ceramic body that contacts the ceramic porous plug.

5. 2. The electrostatic chuck of claim 1, wherein the ceramic porous plug has a grain size that is larger than a grain size of a portion of the ceramic body that contacts the ceramic porous plug.

6. 2. The electrostatic chuck of claim 1, wherein a bottom surface of said ceramic porous plug is coplanar with said bottom surface of said ceramic body.

7. 2. The electrostatic chuck of claim 1, wherein a bottom surface of said ceramic porous plug is recessed from said bottom surface of said ceramic body.

8. 2. The electrostatic chuck of claim 1, wherein a bottom surface of the ceramic porous plug protrudes beyond the bottom surface of the ceramic body.

9. a temperature-controlled base having a top surface secured to the bottom surface of the ceramic body by an adhesive layer, the temperature-controlled base having gas feed holes aligned with the gas flow passages formed in the ceramic body, the bottom surface of the ceramic porous plug extending into the gas feed holes such that the ceramic porous plug shields the adhesive layer from the gas feed holes and the gas flow passages.

9. The electrostatic chuck of claim 8, further comprising:

10. The electrostatic chuck of claim 1 , wherein the ceramic porous plug further comprises regions of differing porosity.

11. The electrostatic chuck of claim 1 , wherein the ceramic porous plug is formed from a composite material.

12. 1. An electrostatic chuck comprising: a ceramic body having a substrate support surface and a bottom surface, an electrode, and a gas passage extending between the substrate support surface and the bottom surface; a ceramic porous plug disposed within the gas flow passage and sintered to the ceramic body; a temperature control base having gas supply holes formed within the ceramic body and aligned with the gas passages configured to flow a backside gas to a support surface of the ceramic body; an adhesive layer that secures the temperature control base to the bottom surface of the ceramic body; 1. An electrostatic chuck comprising:

13. 13. The electrostatic chuck of claim 12, wherein the ceramic porous plug has a grain size that is larger than a grain size of a portion of the ceramic body that contacts the ceramic porous plug.

14. 13. The electrostatic chuck of claim 12, wherein a bottom surface of the ceramic porous plug is coplanar with the bottom surface of the ceramic body.

15. 13. The electrostatic chuck of claim 12, wherein a bottom surface of the ceramic porous plug is recessed from the bottom surface of the ceramic body.

16. 13. The electrostatic chuck of claim 12, wherein a bottom surface of the ceramic porous plug protrudes beyond the bottom surface of the ceramic body.

17. 17. The electrostatic chuck of claim 16, wherein the bottom surface of the ceramic porous plug extends into the gas feed hole of the temperature control base such that the ceramic porous plug shields the adhesion layer from the gas feed hole and the gas flow passage.

18. The electrostatic chuck of claim 12 , wherein the ceramic porous plug further comprises regions of differing porosity.

19. 13. The electrostatic chuck of claim 12, wherein the ceramic body has layered regions of different grain sizes.

20. 1. A method for manufacturing an electrostatic chuck, comprising: disposing a ceramic porous plug at least partially within a hole formed in a sheet of ceramic material, the hole being configured to provide a fluid passageway; sintering said ceramic material and said ceramic porous plug to form a ceramic-to-ceramic bond therebetween; A method for manufacturing an electrostatic chuck, comprising:

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