Yttrium aluminum oxide ceramic plate for an electrostatic chuck

Abstract

An electrostatic chuck having a more erosion-resistant ceramic plate when under exposure to corrosive environments is provided. The electrostatic chuck for use in a processing chamber comprises a ceramic plate comprising yttrium aluminum oxide; an electrically conductive base plate; and a bond layer bonding the ceramic plate to the base plate.

Description

YTTRIUM ALUMINUM OXIDE CERAMIC PLATE FOR AN ELECTROSTATIC CHUCKCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority of U.S. Application No. 63 / 550,350, filed February 6, 2024, which is incorporated herein by reference for all purposes.BACKGROUND

[0002] The background description provided here is for the purpose of generally presenting the context of the disclosure. Information described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0003] The disclosure relates to parts for use in a plasma processing chamber. More specifically, the disclosure relates to the plasma exposed surface of a ceramic plate of an electrostatic chuck of a plasma processing chamber.

[0004] Some surfaces of a ceramic plate are exposed to corrosive plasmas. The corrosive plasma may degrade the plasma exposed surface of the ceramic plate.SUMMARY

[0005] To achieve the foregoing and in accordance with the purpose of the present disclosure, an electrostatic chuck for use in a processing chamber is provided. A ceramic plate comprises yttrium aluminum oxide. A bond layer bonds the ceramic plate to an electrically conductive base plate.

[0006] In another manifestation, a method is provided comprising providing a ceramic plate for an electrostatic chuck comprising a surface comprising yttrium aluminum oxide

[0007] 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

[0008] 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:

[0009] FIG. 1 is a high level flow chart of a process that may be used in an embodiment.

[0010] FIG. 2A is a top view of a mold used in an embodiment.

[0011] FIG. 2B is a cross-sectional side view of the mold shown in FIG. 2A along cut lines2B-2B.

[0012] FIG. 2C is a top view of the mold filled with sintering powder in an embodiment.

[0013] FIG. 2D is a cross-sectional side view of the mold shown in FIG. 2C along cut lines 2D-2D.

[0014] FIG. 2E is a cross-sectional view of the mold in a press and with a pulsed power source.

[0015] FIG. 2F is a top view of a ceramic plate removed from the mold.

[0016] FIG. 2G is a cross-sectional view of the ceramic plate shown in FIG. 2F, along cut lines 2G-2G.

[0017] FIG. 2H is a partial cross-sectional view of an ESC formed with the ceramic plate.

[0018] FIG. 3 is a schematic view of a plasma processing chamber that is used in an embodiment.

[0019] FIG. 4 is a ceramic plate provided in another 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

[0021] The present disclosure will now be described in detail with reference to a few preferred 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] Electrostatic chucks (ESCs) in plasma etch chambers are often formed with an aluminum base plate bonded to an alumina ceramic. The alumina ceramic for modem chambers that utilize coulombic clamping may have low purity alumina (<95 mass%) or, alternately, high purity alumina (>99 mass%). Low purity ceramic formulations often consist of two phases: an amorphous percolated phase that is rich in light metal oxides such as silicates, magnesia, or calcia, and a multi-crystalline phase of alumina. Low purity ceramics, under exposure to corrosive environments, have issues with the silicon-rich glass phase etching out between alumina particles. The corrosive environment may be during plasma processing with wafers, plasma chamber cleaning, or in situ or ex-situ wet cleaning procedures. This damage or removal of the glass phase may lead to poor clamping or dechuck behavior, particle generation as the exposed alumina grains break off, or reduced lifetime. Additionally, for both low purity and high purity alumina, there is some degree of fluorine surface attack. This surface attack results ineither a dielectric electric trapping layer at the surface of the ESC that can cause poor wafer clamping and dechucking or creates a low-density aluminum trifluoride (AIF3) surface that can increase the rate of mechanical wear on the surface of the ESC and reduce lifetime due to backside helium flow rate increases.

[0023] Some embodiments provide a more erosion resistant ceramic plate of an electrostatic chuck. In some embodiments, plasma facing surfaces of the ceramic plate are yttrium aluminum oxide. In some embodiments, the bulk ceramic body of the ceramic plate is yttrium aluminum oxide.

[0024] To facilitate understanding, FIG. 1 is a high level flow chart of an embodiment of a method of forming a ceramic plate using the ceramic plate in a plasma processing chamber. Metal elements are placed in a mold (step 104). FIG. 2A is a top view of part of a mold 208. In this example, the mold 208 comprises an outer ring 212 and a lower punch 216. In this embodiment, the outer ring 212 and the lower punch 216 comprise graphite. FIG. 2B is a side view cross sectional of the mold 208, shown in FIG. 2A, along cut lines 2B-2B, showing a cross sectional view of the outer ring 212 and the lower punch 216. Metal elements 204 are placed on the lower punch 216 in the hole in the outer ring 212. In some embodiments, the metal elements 204 are not placed in the mold 208.

[0025] The mold 208 is filled with a sintering powder 220 (step 108). The sintering powder is a powder that when sintered forms yttrium aluminum oxide. FIG. 2C is a top view of the mold 208 filled with sintering powder 220. FIG. 2D is a cross-sectional view of mold 208 filled with sintering powder 220, shown in FIG. 2C along cut lines 2D-2D. In some embodiments, during the filling of the sintering powder (step 108) additional metal elements 218 are placed in the mold (step 104), so that the additional metal elements are in the middle or on top of the sintering powder 220. Therefore, the placing the metal elements in the mold (step 104), may be before, during, or after the filling the mold with the sintering powder 220 (step 108).

[0026] The sintering powder is then sintered (step 112) to form a ceramic plate. In some embodiments, the sintering is a spark plasma sintering (SPS). In some embodiments, an upper punch 226 is placed over the sintering powder, as shown in FIG. 2E. A pulsed power source 228 is electrically connected between the lower punch 216 and the upper punch 226. In some embodiments, the mold 208 is placed between a lower press 232 and an upper press 236.

[0027] As compared to conventional sintering processes, the SPS process (also referred to as pulsed electric current sintering (PECS), Field-Assisted Sintering (FAST) or Plasma Pressure Compaction (P2C)) involves contemporaneous use of pressure and high-intensity, low-voltage (e.g., 5-12 V), pulsed current to dramatically reduce processing / heating times (e.g., 5-10 minutes(min) instead of several hours) and yield high-density components. In one embodiment, a pulsed direct current (DC) is transmitted by the pulsed power source 228 through the lower punch 216 and the upper punch 226 to the sintering powder, while pressure (e.g. between 10 megapascals (MPa) up to 500 MPa or more) is simultaneously axially applied to the sintering powder from the lower press 232 and upper press 236 through the lower punch 216 and the upper punch 226 to the sintering powder under mono-axial mechanical force. A “mono-axial force” is herein defined to mean a force applied along a single axis or direction creating mono- axial compression. The mold 208 is generally placed under vacuum during at least a portion of the process. Pulsed-current patterns (ON:OFF), typically in milliseconds, enable high heating rates (up to 1000° C / min or more), and rapid cooling / quenching rates of (up to 200° C / min or more) for heating the sintering powder to temperatures ranging from under 1000°C to 2500°C.

[0028] In one embodiment of an SPS process, provided for exemplary purposes only, sintering of the composition of sintering powder is conducted under vacuum (6 < P (Pascals (Pa)) < 14) while being simultaneously subjected to a pulsed current. The SPS thermal treatment may be implemented as follows: 1) a degassing treatment performed for a period between 3 minutes (min) to 10 min, and preferably with the sintering powder subjected to 3 min under limited applied load (e.g. between 10 MPa and 20 MPa) and 2 min under increasing load up to 40 MPa to 100 MPa, and 2) heating up to between 1000° C and 1500° C at 100° C min-1under an applied load between 40 MPa to 100 MPa and a soaking time of 5 min at maximum temperature then cooling down to room temperature. In other embodiments, the temperature range is from 1100° C to 1300° C. It is appreciated that one or more of the SPS process parameters, including composition constituent ratios and particulate size, pressures, temperatures, treatment periods, and current pulse sequences, may be varied as appropriate to optimize the SPS process.

[0029] A ceramic plate is formed by the sintering process and is removed from the mold 208 (step 116). FIG. 2F is a top view of a ceramic plate 240. FIG. 2G is a cross-sectional view of the ceramic plate 240, shown in FIG. 2F along cut lines 2G-2G. The ceramic plate 240 comprises a component body comprising a sintered bulk yttrium aluminum oxide body with metal elements 204, 218. The ceramic plate 240 is characterized by a high degree of densification, reaching nearly 100% (e.g., 99% or greater relative density, and preferably between 99.5% and 100% relative density) with isotropic properties having reduced diffusion between grains and minimized or prevented grain growth. In some embodiments, the average grain size is less than 10 microns (pm). In some embodiments, the average grain size is less than 5 microns. In some embodiments, having a density of at least 99.5% results in a porosity of less than 0.5%, whereporosity is defined by the volume of the pores divided by the total volume. The high density and low grain size result in a higher strength part. Since the ceramic plate 240 is almost entirely yttrium aluminum oxide ceramic, the ceramic plate 240 comprises a bulk yttrium aluminum oxide body. In some embodiments, the bulk yttrium aluminum oxide body comprises at least 50% yttrium aluminum oxide, by weight, where no more than 50% of the bulk yttrium aluminum oxide body remains yttrium oxide and / or aluminum oxide. In some embodiments, the bulk yttrium aluminum oxide body comprises at least 90% yttrium aluminum oxide, by weight, where no more than 10% of the bulk yttrium aluminum oxide body remains yttrium oxide and / or aluminum oxide.

[0030] The ceramic plate 240 may be further processed (e.g., grinding, machining, chemical cleaning, physical cleaning, annealing, or like process) to specifically adapt the ceramic plate 240 to be a component for use in a plasma processing chamber. In an embodiment, the dielectric component is subjected to a grinding in order to control the shape and / or the dimensions of the component. An example of a grinding machine that would be used in an embodiment is a computer numerical control (CNC) grinder.

[0031] In some embodiments, the further processing may further comprise a thermal annealing that is used to relieve internal mechanical stress. The anneal process is performed after sintering. In some embodiments, multiple anneal processes may be provided. For example, a first anneal process may be provided before polishing and then a second anneal process may be provided after the polishing. In an embodiment, the thermal anneal process is used to heat the dielectric component to a temperature above 600° C in an ambient atmosphere for a period of more than 3 hours. In some embodiments, an oxygen or nitrogen rich environment is provided during the annealing. In various embodiments, the annealing is done in a temperature range of 800° C to 1400° C for a time period in the range of 3 hours to 72 hours.

[0032] Next, the further processing may further comprise subjecting the surface of the ceramic plate 240 to a lapping process. A lapping process rubs an abrasive compound against the surface of the dielectric component in order to remove part of the surface of the protective zone 248 in order to reduce the depth of damage without causing additional depth of damage. Lapping is a slower process than grinding, using a finer material to remove peaks created by the grinding process in order to lower surface roughness without increasing the depth of damage. The lapping process may use a fine diamond grit between the component and a plate or pads that provide the rubbing.

[0033] After the lapping is completed, the surface of the ceramic plate 240 is polished. The polishing smooths the surface of the ceramic plate. Polishing is a slower material removalprocess than lapping. The purpose of polishing is not to remove material, but instead to reduce surface roughness. In an embodiment, a finer grit pad is used to remove peaks and valleys that remain after the lapping process. Polishing lowers surface roughness by reducing the number of peaks and valleys. In some embodiments, only parts of the ceramic plate 240 exposed to vacuum need to be subjected to the lapping and polishing. In some embodiments, a surface of the ceramic plate has mesas and a peripheral seal band so that a small percentage of the surface contacts the substrate.

[0034] The ceramic plate 240 is bonded to an electrically conductive base plate in order to form an electrostatic chuck (step 120). FIG. 2H illustrates a partial cross-sectional view of an electrostatic chuck (ESC) 252 forming part of an electrostatic chuck system according to certain embodiments. A ceramic plate 240 is bonded by a bond layer 256 to a base plate 260. In some embodiments, the base plate 260 is made of metal. The bond layer 256, according to some embodiments, may be a polymer adhesive, such as silicone with filler particles to increase the thermal conductivity of the polymer adhesive. In some embodiments, the base plate 260 may contain channels 264 for gas or liquid flow. These channels may, for example, be formed in complex distribution channels in order to cool or heat the electrostatic chuck 252. An O-ring 268 is placed around the ESC 252 surrounding the bond layer 256. In some embodiments, the base plate 260 is formed from at least one of aluminum (Al) or aluminum-silicon carbide (Al-SiC), and the bond layer 105 contains silicone. In some embodiments, the ceramic plate 240 has embedded electrode metal elements 218a and heater metal elements 204a. In some embodiments, the electrode metal elements 218a are used for electrostatic clamping of a substrate. In some embodiments, the heater metal elements 204a provide temperature control. Wafer lift pins 272 may pass through the ESC 252. The wafer lift pins 272 may be used to lift and / or dechuck wafers. In addition, gas passages 276 may pass through the ESC 252 to provide a temperature control gas to the back side of a substrate. The gas passages 276 may pass through an arc suppressor 280. The arc suppressor reduces the arcing or light up of the temperature control gas.

[0035] The ESC 252 is mounted as a component of a plasma processing chamber (step 124). To facilitate understanding, FIG. 3 schematically illustrates an example of a plasma processing chamber system 300 that may be used in an embodiment. The plasma processing chamber system 300 includes a plasma reactor 302 having a plasma processing chamber 304 therein. A plasma power supply 306, tuned by a power matching network 308, supplies power to a transformer coupled plasma (TCP) coil 310 located near a dielectric inductive power window 305. The TCP coil 310 creates a plasma 314 in the plasma processing chamber 304 by providingan inductively coupled power into the plasma reactor 302 through the dielectric inductive power window 305. A pinnacle 372 extends from a chamber wall 376 of the plasma processing chamber 304 to the dielectric inductive power window forming a pinnacle ring. The pinnacle 372 is angled with respect to the chamber wall 376 and the dielectric inductive power window. For example, the interior angle between the pinnacle 372 and the chamber wall 376 and the interior angle between the pinnacle 372 and the dielectric inductive power window may each be greater than 90° and less than 180°. The pinnacle 372 provides an angled ring near the top of the plasma processing chamber 304, as shown. The TCP coil (upper power source) 310 may be configured to produce a uniform diffusion profile within the plasma processing chamber 304. For example, the TCP coil 310 may be configured to generate a toroidal power distribution in the plasma 314. The dielectric inductive power window is provided to separate the TCP coil 310 from the plasma processing chamber 304 while allowing energy to pass from the TCP coil 310 to the plasma processing chamber 304. A wafer bias voltage power supply 316 tuned by a bias matching network 318 provides power to the ESC 252, that acts as a substrate support, to set the bias voltage when a process wafer 366 is placed on the ESC 252. A controller 324 controls the plasma power supply 306 and the wafer bias voltage power supply 316. In some embodiments, the bias network or another electrostatic clamping voltage source is electrically connected to the electrode metal elements 218a, shown in FIG. 2H to provide electrostatic clamping. The electrostatic clamping may be coulombic.

[0036] The plasma power supply 306 and the wafer bias voltage power supply 316 may be configured to operate at specific radio frequencies such as for example, 13.56 megahertz (MHz), 27 MHz, 2 MHz, 60 MHz, 400 kilohertz (kHz), 2.54 gigahertz (GHz), or combinations thereof. Plasma power supply 306 and wafer bias voltage power supply 316 may be appropriately sized to supply a range of powers in order to achieve the desired process performance. For example, in one embodiment, the plasma power supply 306 may supply the power in a range of 50 to 5000 Watts, and the wafer bias voltage power supply 316 may supply a bias voltage in a range of 20 to 2000 volts (V). In addition, the TCP coil 310 and / or the substrate support 364 may be comprised of two or more sub-coils or sub-electrodes. The sub-coils or sub-electrodes may be powered by a single power supply or powered by multiple power supplies.

[0037] As shown in FIG. 3, the plasma processing chamber system 300 further includes a gas source / gas supply mechanism 330. The gas source 330 is in fluid connection with plasma processing chamber 304 through a gas inlet, such as a gas injector 340. The gas injector 340 has at least one borehole 341 to allow gas to pass through the gas injector 340 into the plasma processing chamber 304. The gas injector 340 may be located in any advantageous location inthe plasma processing chamber 304 and may take any form for injecting gas. Preferably, however, the gas inlet may be configured to produce a “tunable” gas injection profile. The tunable gas injection profile allows independent adjustment of the respective flow of the gases to multiple zones in the plasma process chamber 304. More preferably, the gas injector is mounted to the dielectric inductive power window 312. The gas injector may be mounted on, mounted in, or form part of the power window. The process gases and by-products are removed from the plasma process chamber 304 via a pressure control valve 342 and a pump 344. The pressure control valve 342 and pump 344 also serve to maintain a particular pressure within the plasma processing chamber 304. The pressure control valve 342 can maintain a pressure of less than 1 Torr during processing. An edge ring 360 is placed around a top part of the substrate support 364. The gas source / gas supply mechanism 330 is controlled by the controller 324. A temperature controller 380 is controlled by the controller 324. In some embodiments, the temperature controller 380 is electrically connected to at least one heater metal element 204a to provide heating of the ceramic plate. A Kiyo, Strata, or Vector by Lam Research Corp, of Fremont, CA, may be used to practice an embodiment.

[0038] Some embodiments may provide an inductively coupled plasma. Some embodiments may provide a capacitively coupled plasma. Some embodiments may use both inductively coupled power and capacitively coupled power. Some embodiments may provide a plasma without using radio frequency (RF) energy.

[0039] The plasma processing chamber is used to plasma process a plurality of wafers (step 128). The plasma processing performed by the plasma processing chamber may include one or more processes of etching, depositing, passivating, or another plasma process. The plasma processing may also be performed in combination with non-plasma processing. Sequentially processing a large number of wafers may subject the ESC to thousands of hours of a plasma process. The yttrium aluminum oxide ceramic plate 240 is designed to last the lifetime of the processing chamber 304. A processing chamber and the yttrium aluminum oxide ceramic plate 240 may have a lifetime of at least 10,000 RF hours.

[0040] In various embodiments, an yttrium aluminum oxide ceramic may be formed in at least one of two different ways. In some embodiments, an yttrium aluminum oxide ceramic powder may be used. The yttrium aluminum oxide powder may be formed by forming an yttrium aluminum oxide ceramic part and then turning the part into an yttrium aluminum oxide powder. In other embodiments, a mixture of an yttrium oxide powder and an aluminum oxide powder may be used. During sintering, a reactive sintering process takes place causing theyttrium oxide powder and the aluminum oxide powder to form an yttrium aluminum oxide ceramic.

[0041] In some embodiments, the yttrium aluminum oxide ceramic may be one or more of yttrium aluminum garnet (Y3AI5O12 (YAG)), yttrium aluminum monoclinic (Y4AI2O9 (YAM)), or yttrium aluminum perovskite (YAIO3 (YAP)). In some embodiments, the ceramic is at least 90% by weight pure yttrium aluminum oxide. In some embodiments, the ceramic is at least 99% by weight pure yttrium aluminum oxide. In some embodiments, the yttrium aluminum oxide is at least 50% by weight YAG. In some embodiments, the yttrium aluminum oxide is at least 90% by weight YAG. In some embodiments, other sintering processes may be used.

[0042] The yttrium aluminum oxide surface is more corrosion resistant than an aluminum oxide surface. The yttrium aluminum oxide surface has a lower erosion rate than an aluminum oxide surface. In some tests, it has been found that the erosion rate for yttrium aluminum oxide is less than 0.5 times the erosion rate of aluminum oxide for sub 100 eV ions in a corrosive fluorine or halogen type environment.

[0043] As a result, some embodiments provide an ESC that is able to last the lifetime of the process chamber for over 10,000 RF hours. In addition, the ESC provides fewer contaminant particles than the prior art, resulting in fewer defects. In addition, some embodiments provide a large enough SPS ceramic plate with embedded metal elements. When using SPS layers of powders of different materials are provided. For instance, the lower layer comprises aluminum oxide while the top layer comprises yttrium aluminum oxide.

[0044] In some embodiments, the ceramic plate 240 is formed using an additive green sheet manufacturing process. Green sheet manufacturing is a layer-by-layer additive process to create a final form. One starts by combining a ceramic powder with an organic binder and a solvent, and mixing them in a mill, such as a ball mill. This mixture is then poured out and cast into a thin sheet, often less than 1 mm in thickness. The sheet is dried to create what is called a ‘green’ sheet; this is analogous to a ‘green’ body for bulk ceramic manufacturing. ‘Green’ simply refers to the fact that the ceramic is not in its final sintered form. These sheets can then be stacked on top of each other to create a larger object. In some cases, metal layers may be placed in between the green sheets via various methods (wire, printing, etc.). These bodies that are now made up of stacked green sheets are then baked out to remove the organic binders and then sintered at higher temperatures to have a ceramic body. In some embodiments, metal layers are printed during the additive green sheet manufacturing process. In some embodiments, the ceramic plate 240 is formed using a thermal sintering process instead of a spark plasma sintering process.Coatings

[0045] In some embodiments, an yttrium aluminum oxide coating is placed on a plasma facing surface of a ceramic plate. FIG. 4 is a cross-sectional view of a ceramic plate 408 comprising a ceramic component body 404 with metal elements 416 and an yttrium aluminum oxide coating 420 on plasma facing surfaces of the ceramic component body 404.

[0046] In some embodiments, the yttrium aluminum oxide coating is applied using a thermal spray, such as an atmospheric plasma spray coating. Atmospheric plasma spraying (APS) is a type of thermal spraying in which a torch is formed by applying an electrical potential between two electrodes, leading to the ionization of an accelerated gas (a plasma). Torches of this type can readily reach temperatures of thousands of degrees Celsius, liquefying high melting point materials such as ceramics. Particles of the desired materials, in this embodiment alumina and yttria or another variety of powders that form yttrium aluminum oxide, are injected into the jet, melted, and then accelerated towards the substrate so that the molten or plasticized material coats the surface of the component and cools, forming a solid, conformal coating. These processes are distinct from vapor deposition processes that use vaporized material instead of molten material. In some embodiments, the coating has a thickness in the range of 20 microns to 1 mm. In some embodiments, the yttrium aluminum oxide coating is applied by using physical vapor deposition (PVD) to provide a physical vapor deposition coating. In some embodiments, a cosintered coating may be provided using cosintering. An example of cosintering provides a layer of sintering powder that forms yttrium aluminum oxide against at least one surface of a mold. The remainder of the mold may be filled with aluminum oxide. The yttrium aluminum oxide powder would have a thickness in the range of 300 microns to 8 mm. Aluminum oxide powder would fill up the remainder of the mold. The sintering process forms an yttrium aluminum oxide coating on an aluminum oxide body. In some embodiments, the sintered part is 20 to 40 volume% yttrium aluminum oxide and 60 to 80 volume% aluminum oxide. The cosintering can be carried out using SPS. In some embodiments, the coating may be at least one of a physical vapor deposition (PVD) coating using an e-beam or magnetron deposition, a high velocity oxygen fuel coating, or an aerosol deposition coating. In some embodiments, the bulk ceramic body would be primarily alumina (greater than 90 mass% with other additives such as silicates for sintering purposes; or greater than 99 mass% as a higher purity option). In some embodiments, the bulk ceramic body comprises a toughened alumina such as ZTA (zirconia toughened alumina), where zirconia normally spans 10-20% atomic percent to aluminum (90- 80%).

[0047] In some embodiments, yttrium aluminum oxide coatings are not able to provide protection for the lifetime of the process chamber.

[0048] While this disclosure has been described in terms of several preferred embodiments, there are alterations, permutations, and various substitute equivalents, that 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, 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 for use in a processing chamber, comprising: a. a ceramic plate comprising yttrium aluminum oxide; b. an electrically conductive base plate; and c. a bond layer bonding the ceramic plate to the base plate.

2. The electrostatic chuck, as recited in claim 1, wherein the ceramic plate comprises a bulk yttrium aluminum oxide body.

3. The electrostatic chuck, as recited in claim 2, wherein the ceramic plate further comprises at least one metal element embedded in the bulk yttrium aluminum oxide body.

4. The electrostatic chuck, as recited in claim 2, wherein the yttrium aluminum oxide comprises yttrium aluminum garnet.

5. The electrostatic chuck, as recited in claim 4, wherein the yttrium aluminum oxide is at least 50% yttrium aluminum garnet by weight.

6. The electrostatic chuck, as recited in claim 2, wherein the bulk yttrium aluminum oxide body is a spark plasma sintered bulk yttrium aluminum oxide body.

7. The electrostatic chuck, as recited in claim 2, wherein the bulk yttrium aluminum oxide body is a sintered bulk yttrium aluminum oxide body.

8. The electrostatic chuck, as recited in claim 1, wherein the ceramic plate comprises: a bulk ceramic body comprising alumina; and an yttrium aluminum oxide coating on a surface of the bulk ceramic body.

9. The electrostatic chuck, as recited in claim 8, wherein the yttrium aluminum oxide coating has a thickness in a range of 20 microns to 1 mm.

10. The electrostatic chuck, as recited in claim 9, wherein the bulk ceramic body comprises at least one embedded metal element.

11. A method, comprising providing a ceramic plate for an electrostatic chuck comprising a surface comprising yttrium aluminum oxide.

12. The method, as recited in claim 11 , wherein the providing a ceramic plate comprises: placing a sintering powder in a mold; and sintering the sintering powder to form an yttrium aluminum oxide ceramic.

13. The method, as recited in claim 12, wherein the sintering powder comprises yttrium aluminum oxide powder.

14. The method, as recited in claim 12, wherein the sintering powder comprises a mixture of yttrium oxide powder and aluminum oxide powder.

15. The method, as recited in claim 12, wherein the sintering is a spark plasma sintering.

16. The method, as recited in claim 12, further comprising placing at least one metal element in the mold.

17. The method, as recited in claim 12, wherein the sintering of the sintering powder forms yttrium aluminum garnet.

18. The method, as recited in claim 11, wherein the providing the ceramic plate for an electrostatic chuck comprising a surface comprising an yttrium aluminum oxide, comprises: providing a ceramic plate: and forming an yttrium aluminum oxide coating on at least one surface of the ceramic plate.

19. The method, as recited in claim 18, wherein the forming the yttrium aluminum oxide coating comprises providing at least one of a thermal spray coating, a cosintered coating, and a physical vapor deposition coating.

20. The method, as recited in claim 11, wherein the providing a ceramic plate comprises: forming the ceramic plate using an additive green sheet manufacturing process; and printing metal layers during the additive green sheet manufacturing process.

Images