Ceramic engineering with material gradients

Abstract

[0005] Embodiments disclosed herein include a puck for an electrostatic chuck. In embodiments, the puck comprises a substrate having a top surface and a bottom surface. In embodiments, a first material composition is on the top surface of the substrate and a second material composition is on the bottom surface of the substrate. In embodiments, a composition gradient is provided across the substrate between the top surface and the bottom surface.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 18 / 112,988, filed February 22, 2023, which claims the benefit of U.S. Provisional Application No. 63 / 326,599, filed April 1, 2022, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE

[0002] Embodiments relate to the field of semiconductor manufacturing, and more particularly to ceramic pucks for electrostatic chucking architectures that include a graded material composition. [Background technology]

[0003] In semiconductor manufacturing processes, chucks are used to secure a semiconductor substrate (e.g., a wafer) to a flat surface for processing. Often the chuck is an electrostatic chuck, i.e., an electrostatic force generated by the chuck is applied to the semiconductor substrate to attract and secure the semiconductor substrate to the chuck. Generally, the chuck includes a base plate and a puck on the base plate. In some cases, one or both of the base plate and the puck may be temperature controlled. The puck may be secured to the base plate by an adhesive or other bonding architecture (e.g., diffusion bonding, etc.).

[0004] Existing chucking architectures have limited performance because the puck must be optimized for given conditions, which may require sacrificing overall performance. For dielectric etch products, thermal uniformity limitations may prevent dielectric etch processes from running at high plasma loads. For conductor etch products, the interface between the ceramic layer of the puck, the bonding material, and the metal base plate prevents the puck from achieving high thermal uniformity at high temperatures. For deposition products, the clamping force loss of AlN at high temperatures prevents an expansion of the operating process window. For deposition and etch products, the ceramic of the puck is susceptible to erosion by halogen plasma-induced particles. Summary of the Invention

[0005]

[0005] Embodiments disclosed herein include a puck for an electrostatic chuck. In an embodiment, the puck comprises a substrate having a top surface and a bottom surface. In an embodiment, a first material composition is on the top surface of the substrate and a second material composition is on the bottom surface of the substrate. In an embodiment, a composition gradient is provided across the substrate between the top surface and the bottom surface.

[0006]

[0013] Embodiments disclosed herein further include a puck for an electrostatic chuck. In an embodiment, the puck comprises a substrate and a first material composition within the substrate. In an embodiment, a second material composition is provided within the substrate. In an embodiment, a compositional gradient is provided between the first material composition and the second material composition.

[0007] The embodiment may further include an electrostatic chuck. In an embodiment, the electrostatic chuck comprises a base plate and a puck bonded to the base plate. In an embodiment, the puck includes a substrate and a first material composition in the substrate. In an embodiment, a second material composition is provided in the substrate. In an embodiment, the puck further includes a compositional gradient between the first material composition and the second material composition. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of an electrostatic chuck. [Figure 2A] FIG. 2 is a cross-sectional view of a puck of an electrostatic chuck including a first material composition and a second material composition, with a compositional gradient between the first material composition and the second material composition, according to an embodiment. [Figure 2B] FIG. 2 is a cross-sectional view of a puck of an electrostatic chuck including a first material composition and a second material composition, with a compositional gradient between the first material composition and the second material composition, according to an embodiment. [Figure 3A] FIG. 1 is a plan view of a pack having a first material composition in the center of the pack and a second material composition at the edge of the pack with a radial compositional gradient between the first and second material compositions, according to an embodiment. [Figure 3B]FIG. 1 is a plan view of a puck having a first material composition at a first edge of the puck, a second material composition at a second edge of the puck, and a compositional gradient between the first and second material compositions, according to an embodiment. [Figure 4A] FIG. 2 is a cross-sectional view of a pack having a first material composition, a second material composition, and a third material composition with a compositional gradient between layers, according to an embodiment. [Figure 4B] FIG. 2 is a cross-sectional view of an electrostatic chuck with a puck including three material compositions with a compositional gradient therebetween, according to an embodiment. [Figure 4C] FIG. 2 is a cross-sectional view of a pack having a first material composition, a second material composition, and a third material composition with a compositional gradient between layers, according to an embodiment. [Figure 4D] FIG. 2 is a cross-sectional view of an electrostatic chuck with a puck including three material compositions with a compositional gradient therebetween, according to an embodiment. [Diagram 5] 1 is a cross-sectional view of a puck having a first material composition, a second material composition directly below the first material composition, and a third material composition at the bottom of the puck, according to an embodiment. [Figure 6] FIG. 1 is a cross-sectional view of a puck having a first material composition having a first grain size and a second material composition having a second grain size, and a grain size gradient between the first and second material compositions, according to an embodiment. [Figure 7A] FIG. 2 is a cross-sectional view of a puck having a diffusion source on a surface of the puck, according to an embodiment. [Figure 7B] FIG. 7B is a cross-sectional view of the pack of FIG. 7A after a diffusion process has been performed, according to an embodiment. [Figure 8A] FIG. 2 is a cross-sectional view of a puck having a diffusion source embedded in the puck, according to an embodiment. [Figure 8B] FIG. 8B is a cross-sectional view of the pack of FIG. 8A after a diffusion process has been performed, according to an embodiment. [Figure 9] FIG. 2 is a cross-sectional view of a puck having a mesa and a first material composition and a second material composition according to an embodiment. [Figure 10]FIG. 2 is a block diagram of an exemplary computer system that may be used with a processing tool, according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The systems described herein include ceramic pucks for electrostatic chucking architectures that include a graded material composition. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. It will be apparent to one of ordinary skill in the art that the embodiments may be practiced without these specific details. In other instances, well-known aspects have not been described in detail so as not to unnecessarily obscure the embodiments. It should be further understood that the various embodiments illustrated in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0010] As mentioned above, semiconductor processing tools typically employ a chuck to secure a substrate (e.g., a wafer) to a flat surface for processing. The chuck is often an electrostatic chuck that includes a base plate and a puck on the base plate. In the case of an electrostatic chuck, the puck also includes an electrode to provide the electrostatic charge that secures the substrate to the chuck. The puck is typically a ceramic material.

[0011] There are several design considerations that must be taken into account when selecting the puck material. Chuck strength, temperature uniformity, and resistance to etching chemistries are some of the design considerations that may be used in the design of the puck. Unfortunately, such design considerations can result in a chuck optimized for one application sacrificing performance in other areas. This is especially true when the puck is made from a single material, as is common in existing architectures.

[0012] An example of a chuck 150 is provided in FIG. 1. As shown, a base plate 151 may be coupled to the puck 120 by an adhesive layer 153. Cooling channels 152 may be provided in the base plate 151, and an electrode 121 may be provided in the puck 120. A backside gas line 154 may provide gas (e.g., helium) to the backside of the substrate (not shown) for thermal control purposes. As shown, the puck 120 includes a single material. For example, the puck 120 may include Al2O3 or AlN in some embodiments. In other embodiments, the puck 120 may include a material that is more resistant to etching chemistries, such as Y2O3. Unfortunately, providing a single material limits the performance of the puck 120.

[0013] Thus, embodiments disclosed herein include packs having multiple material compositions. For example, a first side of the pack may have a first material composition and a second side of the pack may have a second material composition. Additionally, there may be a compositional gradient between the first and second material compositions. That is, embodiments may include packs having a material composition that varies continuously through the thickness of the pack, or packs having a material composition that varies radially. In some embodiments, other compositional gradient directions may also be used.

[0014] The pack material may include a ceramic-ceramic gradient, a ceramic-metal gradient, a ceramic-polymer gradient, or a metal-polymer gradient. In certain embodiments, the ceramic material may include metal oxides, nitrides, carbides, borides, fluorides, silicides, sulfides, etc. In the case of metal oxides, the metal components may include aluminum, copper, molybdenum, tungsten, titanium, graphite, etc.

[0015] Reference is now made to FIG. 2A, which is a cross-sectional view of a puck 220 for an electrostatic chuck according to an embodiment. In an embodiment, the puck 220 may include a substrate 230. The electrode 221 may be disposed within the substrate 230. The substrate 230 may have a thickness of about 0.1 mm to about 20 mm. The substrate 230 may include a ceramic material in some cases. However, it should be understood that other material classes (e.g., metals) may be included in the substrate 230.

[0016] In an embodiment, the substrate 230 may include a first material composition 231 on the top surface and a second material composition 232 on the bottom surface. Additionally, a composition gradient 235 may be provided between the first material composition 231 and the second material composition 232. That is, the material composition of the substrate 230 may vary through the thickness of the puck 220. More specifically, the embodiment shown in FIG. 2A differs from a situation where a first layer is on the top surface of the substrate and a second layer is on the bottom surface of the substrate, where the substrate has a single material composition through its thickness. However, it should be understood that the embodiment may include an architecture having a first layer on the top surface of the substrate and a second layer on the bottom surface of the substrate and the substrate being of a single material composition. For example, the first layer may include 90% Al2O3 and 10% AlN, the second layer may include 90% AlN and 10% Al2O3, and the substrate may include 50% AlN and 50% Al2O3.

[0017] In an embodiment, the first material composition 231 may include a single first solid solution phase and the second material composition 232 may include a single second solid solution phase. For example, the composition gradient 235 may start with one material and end with a second material. In one embodiment, the first solid solution phase may include 100% Al2O3 and the second solid solution phase may include 100% AlN. The composition gradient 235 may change from an Al2O3-rich material composition at the top of the substrate 230 to an AlN-rich material composition at the bottom of the substrate 230. For example, at a midpoint between the first material composition 231 and the second material composition 232, the composition gradient 235 may have about 50% Al2O3 and about 50% AlN. Of course, it should be understood that the composition gradient 235 does not have to be linear. For example, the location where the compositional gradient 235 has about 50% Al2O3 and about 50% AlN may be closer to the first material composition 231 or may be closer to the second material composition. In an embodiment, the proportion of one of the material compositions may increase monotonically through the thickness of the substrate 230.

[0018] In additional embodiments, the first material composition 231 and the second material composition 232 may include two different solid solution phases. For example, the first material composition 231 may include about 70% Al2O3 and about 30% AlN. In some cases, the second material composition 232 may include about 100% AlN. In other embodiments, the second material composition 232 may include about 70% AlN and about 30% Al2O3. That is, the compositional gradient 235 is not limited to a change from a first solid solution phase to a second solid solution phase. Instead, embodiments may include a compositional gradient 235 that transforms a first material composition having a pair of solid solution phases into a second material composition having a pair of solid solution phases.

[0019] In the case of Al2O3 and AlN substrates 230, an Al2O3 rich top material composition 231 increases the clamping force at higher operating temperatures. AlN has high thermal conductivity, improving temperature uniformity in the puck 220.

[0020] Although the first material composition 231 and the second material composition 232 have been described as being metal oxides and metal nitrides, it should be understood that other material classes may be used for the first material composition 231 and the second material composition 232. For example, the materials may include carbides, borides, fluorides, silicides, sulfides, etc. Additionally, metallic materials such as aluminum, copper, molybdenum, tungsten, titanium, graphite, etc. may also be used.

[0021] Reference is now made to Figure 2B, which is a cross-sectional view of a puck 220 according to an additional embodiment. As shown, puck 220 has the opposite shading to puck 220 in Figure 2A. That is, material compositions that were at the bottom of substrate 230 in Figure 2A are at the top of substrate 230 in Figure 2B. Similarly, material compositions that were at the top of substrate 230 in Figure 2A are at the bottom of substrate 230 in Figure 2B.

[0022] For example, the first material composition 231 may include AlN and the second material composition 232 may include Al2O3. The above embodiment may result in improved heat transfer at higher plasma loads and increased clamping force. The clamping force may increase as a result of the effective electrical distance being reduced. Additionally, encasing the electrode 221 in Al2O3 controls charge transport and improves the performance of the pack 220.

[0023] In Figures 2A and 2B, a composition gradient 235 is provided through the thickness of the substrate 230. However, embodiments are not limited to the above configurations. For example, in Figures 3A and 3B, different composition gradient directions are provided.

[0024] Reference is now made to Figure 3A, which is a plan view of a pack 320 according to an embodiment. In an embodiment, the pack 320 comprises a substrate 330. In an embodiment, a first material composition 333 may be provided approximately at the center of the substrate 330, and a second material composition 334 may be provided at the periphery of the substrate 330. A compositional gradient 335 extends outward from the first material composition 333 to the second material composition 334. That is, the compositional gradient 335 may be a radial compositional gradient.

[0025] In embodiments, the first material composition 333 and the second material composition 334 may be similar to the first material composition 231 and the second material composition 232 described in more detail above. For example, the first material composition 333 may include Al2O3 and the second material composition 334 may include AlN. However, it should be understood that the first material composition 333 and the second material composition 334 may be reversed. Furthermore, the first material composition 333 and the second material composition 334 may include two solid solution phases in some embodiments. In embodiments, the solid solution phase increases monotonically in the radial direction. In other embodiments, the solid solution phase is arranged to increase linearly along the composition gradient 335.

[0026] Reference is now made to Figure 3B, which is a top view of a puck 320 according to an additional embodiment. In an embodiment, puck 320 comprises a substrate 330. Substrate 330 may include a first material composition 336 at a first edge of substrate 330 and may include a second material composition 337 at a second edge of substrate 330. In an embodiment, a compositional gradient 335 extends between first material composition 336 and second material composition 337 across a surface of substrate 330.

[0027] In embodiments, the first material composition 336 and the second material composition 337 may be similar to the first material composition 231 and the second material composition 232 described in more detail above. For example, the first material composition 336 may include Al2O3 and the second material composition 337 may include AlN. However, it should be understood that the first material composition 336 and the second material composition 337 may be reversed. Furthermore, the first material composition 336 and the second material composition 337 may include two solid solution phases in some embodiments. In embodiments, the solid solution phase increases monotonically across the substrate 330. In other embodiments, the solid solution phase is arranged to increase linearly along the composition gradient 335.

[0028] In the embodiments described above, a pair of material compositions are provided within the pack, however, it should be understood that embodiments may include two or more different material compositions.

[0029] 4A, which is a cross-sectional view of an embodiment of a pack 420. In an embodiment, the pack 420 includes a substrate 430 and an electrode 421. As shown, a first material composition 431 is disposed on a top surface of the substrate 430, a second material composition 432 is disposed on a bottom surface of the substrate 430, and a third material composition 438 is disposed between the top and bottom surfaces of the substrate 430.

[0030] In some embodiments, the first material composition 431 and the second material composition 432 include the same material, and the third material composition 438 includes a different material composition. For example, the first material composition 431 and the second material composition 432 may include Al2O3, and the third material composition 438 may include AlN. Compositional Gradient 435 A may be provided between the first material composition 431 and the third material composition 438, forming a composition gradient 435 B may be provided between the third material composition 438 and the second material composition 432.

[0031] In embodiments, the third material composition 438 may be located at a midpoint between the first material composition 431 and the second material composition 432. In other embodiments, the distance between the third material composition 438 and the first material composition 431 may be different than the distance between the third material composition 438 and the second material composition 432. For example, the third material composition 431 may be closer to the first material composition 431 than the second material composition 432, or vice versa.

[0032] Reference is now made to Figure 4B, which illustrates a cross-sectional view of an embodiment of a chuck 450. In an embodiment, the chuck 450 includes a puck 420 disposed on a base plate 451. The chuck 450 may include a substrate 430 having a first material composition 431, a second material composition 432, and a third material composition 438. A compositional gradient 435 between the different material compositions may be provided. A and 435 B In an embodiment, the base plate 451 may include cooling channels 452.

[0033] In an embodiment, the puck 430 is diffusion bonded to the base plate 451. For example, the second material composition 432 and the base plate 451 can comprise the same material. By comprising the same material at the interface, stresses (due to mismatch in coefficient of thermal expansion (CTE)) are reduced. Although a diffusion bonded interface is illustrated, it should be understood that embodiments can also include an adhesive bond between the second material composition 432 and the base plate 451.

[0034] Reference is now made to Figure 4C, which is a cross-sectional view of a pack 420 according to an additional embodiment. As shown in Figure 4C, the substrate 420 includes three material compositions 431, 432, and 438. However, in contrast to the embodiment depicted in Figures 4A and 4B, the three material compositions 431, 432, and 438 are different material compositions. For example, the first material composition 431 may include Al2O3, the second material composition 432 may include a metal, and the third material composition 438 may include AlN. Compositional Gradient 435 A and 435 B may be provided through the thickness of the substrate 420 between the material compositions 431 , 432 , and 438 .

[0035] 4D, which is a cross-sectional view of an embodiment of a chuck 450. In an embodiment, the chuck 450 includes a puck 420 disposed on a base plate 451. The chuck 450 may include a substrate 430 having a first material composition 431, a second material composition 432, and a third material composition 438. A compositional gradient 435 between the different material compositions may be provided. A and 435 B In an embodiment, the base plate 451 may include cooling channels 452.

[0036] In an embodiment, the puck 430 is diffusion bonded to the base plate 451. For example, the second material composition 432 and the base plate 451 can comprise the same material. By comprising the same material at the interface, stresses (due to CTE mismatch) are reduced. Although a diffusion bonded interface is illustrated, it should be understood that embodiments can also include an adhesive bond between the second material composition 432 and the base plate 451.

[0037] Reference is now made to FIG. 5, which is a cross-sectional view of a pack 520 according to an additional embodiment. In an embodiment, the pack 520 includes a substrate 530, an electrode 521, and a plurality of material composition layers. For example, the pack 520 may include a first material composition 531, a second material composition 532, and a third material composition 539. In an embodiment, the third material composition 539 may be provided on a top surface of the substrate 530. The third material composition 539 may include a material that is resistant to an etching chemistry (e.g., a halogen etching chemistry). For example, the third material composition 539 may include Y2O3. In the illustrated embodiment, the third material composition 539 is directly above the first material composition 531. However, it should be understood that a compositional gradient may be provided between the first material composition 531 and the third material composition 539. In an embodiment, the compositional gradient 535 may be provided between the first material composition 531 and the second material composition 532.

[0038] Reference is now made to FIG. 6, which is a cross-sectional view of a pack 620 according to an additional embodiment. In an embodiment, the pack 620 may include a substrate 630 having an embedded electrode 621. In an embodiment, a first material composition 631 may be on top of the substrate 630 and a second material composition 632 may be on the bottom of the substrate 630. As shown, the material compositions 631 and 632 differ from one another in terms of average grain size. That is, the elemental materials of the material compositions 631 and 632 may be the same, but the grain sizes are different. For example, the first material composition 631 may include AlN having a first grain size and the second material composition 632 may include AlN having a second grain size. As shown, the second grain size is smaller than the first grain size. In an embodiment, a grain size gradient 641 may be provided through the thickness of the substrate 630 to transition from the first grain size to the second grain size. In other embodiments, the first material composition 631 and the second material composition 632 may have different elemental compositions and different average grain sizes. For example, the first material composition 631 may include Al2O3 having a first grain size and the second material composition 632 may include AlN having a second (smaller) grain size.

[0039] Reference is now made to Figures 7A and 7B, which are a pair of cross-sectional views illustrating a process for forming a compositional gradient in accordance with an embodiment. In Figure 7A, a puck 720 is shown having a substrate 730 and an embedded electrode 721. In an embodiment, a first material composition 761 may be provided on a bottom surface of the substrate 730. For example, the first material composition 761 may include Al2O3 or AlN.

[0040] Reference is now made to Figure 7B, which is a cross-sectional view of the puck 720 after a diffusion process according to an embodiment. For example, the puck 720 may be exposed to an elevated temperature to promote diffusion of the solid solution of the first material composition 761 into the substrate 730. As shown, a second material composition 762 may be provided on top of the substrate 730. The second material composition may include a lower percentage of the solid solution from the first material composition 761 than the first material composition 761. The diffusion process may also form a compositional gradient 765 across the thickness of the substrate 730.

[0041] In embodiments, the first material composition 761 may be either in a green state, partially sintered, or sintered. In some embodiments, the first material composition 761 may be a sacrificial layer, i.e., remaining portions of the first material composition may be removed (e.g., using a grinding or polishing process) after the diffusion process.

[0042] Reference is now made to Figures 8A and 8B, which are a pair of cross-sectional views illustrating a process for forming a compositional gradient in accordance with an embodiment. In Figure 8A, a puck 820 is shown having a substrate 830 and an embedded electrode 821. In an embodiment, a first material composition 861 may be provided in the center of the substrate 830. For example, the first material composition 861 may include Al2O3 or AlN.

[0043] Reference is now made to FIG. 8B, which is a cross-sectional view of puck 820 after a diffusion process according to an embodiment. For example, puck 820 may be exposed to an elevated temperature to promote diffusion of the solid solution of first material composition 861 into substrate 830. As shown, the solid solution of second material composition 862 may be exposed to an elevated temperature to promote diffusion of the solid solution of first material composition 861 into substrate 830. A may be provided on the top surface of the substrate 830, and a third material composition 862 B may be provided on the bottom surface of the substrate 830. A and a third material composition 862 B may contain a lower percentage of solid solution from the first material composition 861 than the first material composition 861. The diffusion process may also create a composition gradient 865 across the thickness of the substrate 830. A and 865 B may also be formed.

[0044] In Figures 7A-8B, the diffusion process involves a physical layer that is the source of material that is diffused through the substrate. However, it should be understood that the gradient can be formed in other ways. For example, the sintering environment (e.g., gas composition) can be changed (e.g., gas concentration can be increased or decreased) to change the amount of gas component that is incorporated into the substrate during the sintering process.

[0045] Reference is now made to FIG. 9, which is a cross-sectional view of a puck 920 according to an additional embodiment. In an embodiment, the puck 920 includes a substrate 930 and an embedded electrode 921. A first material composition 931 may be provided on a top surface of the substrate 930, and a second material composition 932 may be provided on a bottom surface of the substrate 930. In an embodiment, a compositional gradient 935 between the first material composition 931 and the second material composition 932 may be provided through a thickness of the substrate 930. In an embodiment, a mesa 970 may be formed on the top surface of the substrate 930. While previous embodiments have been illustrated without the mesa 970, it should be understood that any of the embodiments disclosed herein may also include a mesa similar to the mesa 970 of FIG.

[0046] It is understood that the compositional gradients described herein can take the form of changes in various material properties. For example, the compositional gradients described herein can refer to changes in one or more of material type, grain size, crystallite size, porosity, and material attributes (e.g., CTE, Young's modulus, Poisson's ratio, thermal conductivity, hardness, resistivity, etc.).

[0047] Further, it should be understood that the embodiments described herein can be fabricated using a variety of processes. For example, green sheet lamination, hot pressing, cold isostatic pressing, electric current sintering, electrophoretic deposition, laser sintering, 3D printing, sol-gel, gel casting, or combinations thereof can be used to form a puck with a composition gradient. In some embodiments, the entire ceramic body can be co-sintered or sintered in multiple steps. The sintering temperature can range from 20° C. to 2000° C. In some embodiments, the gradient can be achieved during the sintering process by changing the ambient gas composition (e.g., changing O2 gas, changing partial pressure, changing gas species, etc.). The size of the raw powder can vary from about 1 nm up to about 500 μm. In embodiments, the ceramic material can be piezoelectric (e.g., AlN, PZT, BaTiO3-based, SrTiO3-templated, etc.). In other embodiments, the ceramic material can be piezoresistive. The thickness of the substrate for the puck can range from about 0.1 mm to about 20 mm.

[0048] Reference is now made to FIG. 10, which is a block diagram illustrating an exemplary computer system 1000 of a processing tool according to an embodiment. In an embodiment, the computer system 1000 is coupled to the processing tool and controls processing within the processing tool. The computer system 1000 may be connected (e.g., networked) to other machines in a local area network (LAN), an intranet, an extranet, or the Internet. The computer system 1000 may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The computer system 1000 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile phone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be performed by the machine. Additionally, although only a single machine is illustrated in computer system 1000, the term "machine" is intended to include any collection of machines (e.g., computers) that individually or collectively execute a set of instructions (or multiple sets of instructions) for performing any one or more of the methodologies described herein.

[0049] The computer system 1000 may include a computer program product, or software 1022, having a non-transitory machine-readable medium having instructions stored thereon, which may be used to program the computer system 1000 (or other electronic devices) to perform processes according to embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, machine-readable (e.g., computer-readable) media includes machine (e.g., computer) readable storage media (e.g., read-only memory ("ROM"), random access memory ("RAM"), magnetic disk storage media, optical storage media, flash memory devices, etc.), machine (e.g., computer) readable transmission media (electrical, optical, acoustic, or other forms of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0050] In an embodiment, computer system 1000 includes a system processor 1002, a main memory 1004 (e.g., read only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 1006 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory 1018 (e.g., a data storage device), which communicate with each other via a bus 1030.

[0051] The system processor 1002 represents one or more general purpose processing devices, such as a microsystem processor, a central processing unit, etc. More specifically, the system processor may be a complex instruction set computing (CISC) microsystem processor, a reduced instruction set computing (RISC) microsystem processor, a very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or a system processor implementing a combination of instruction sets. The system processor 1002 may also be one or more special purpose processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal system processor (DSP), a network system processor, etc. The system processor 1002 is configured to execute processing logic 1026 for performing the operations described herein.

[0052] The computer system 1000 may further include a system network interface device 1008 for communicating with other devices or machines. The computer system 1000 may also include a video display device 1010 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 1012 (e.g., a keyboard), a cursor control device 1014 (e.g., a mouse), and a signal generating device 1016 (e.g., a speaker).

[0053] The secondary memory 1018 may include a machine-accessible storage medium 1031 (or more specifically, a computer-readable storage medium) having stored thereon one or more sets of instructions (e.g., software 1022) embodying any one or more of the methodologies or functions described herein. The software 1022 may also reside, completely or at least partially, within the main memory 1004 and / or within the system processor 1002 during its execution by the computer system 1000, with the main memory 1004 and the system processor 1002 also constituting machine-readable storage media. The software 1022 may further be transmitted or received over the network 1061 via the system network interface device 1008. In an embodiment, the network interface device 1008 may operate using RF, optical, acoustic, or inductive coupling.

[0054] While the machine-accessible storage medium 1031 is shown to be a single medium in the exemplary embodiment, the term "machine-readable storage medium" should be interpreted to include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) that store one or more sets of instructions. The term "machine-readable storage medium" is also intended to include any medium capable of storing or encoding a set of instructions for execution by a machine, causing the machine to perform any one or more of the methodologies. Thus, the term "machine-readable storage medium" should be interpreted to include, but is not limited to, solid-state memories, optical media, and magnetic media.

[0055] In the foregoing specification, certain exemplary embodiments have been described. It will be apparent that various modifications may be made thereto without departing from the scope of the following claims. The specification and drawings are therefore to be regarded in an illustrative rather than a restrictive sense.

Claims

1. A pack for an electrostatic chuck, comprising: a substrate having a top surface and a bottom surface; a first material composition on an upper surface of the substrate; a second material composition on a bottom surface of the substrate; and a compositional gradient across the substrate between the top surface and the bottom surface; Equipped with a pack.

2. 10. The pack of claim 1, wherein the first material composition comprises up to 100% of a first solid solution phase and the second material composition comprises up to 100% of a second solid solution phase.

3. The first solid solution phase is Al ２ O ３ 3. The pack of claim 2, wherein the second solid solution phase comprises AlN.

4. The first solid solution phase includes AlN, and the second solid solution phase includes Al ２ O ３ 3. The pack of claim 2 comprising:

5. 2. The pack of claim 1, wherein the first material composition comprises a first solid solution phase and a second solid solution phase, and the second material composition comprises a first solid solution phase and a second solid solution phase, and a fraction of the second solid solution phase in the second material composition is less than a fraction of the second solid solution phase in the first material composition.

6. 10. The pack of claim 1, wherein the first material composition and the second material composition comprise one or more of a metal oxide, a nitride, a carbide, a boride, a fluoride, a silicide, and a sulfide.

7. 10. The pack of claim 1, wherein the metal oxide comprises one or more of aluminum, copper, molybdenum, tungsten, and graphite.

8. 8. The pack of claim 7, wherein the metal comprises 0.01% or more of the material composition.

9. a third material composition between the first material composition and the second material composition, the composition gradient comprising a first gradient between the first material composition and the third material composition and a second gradient between the third material composition and the second material composition; The pack of claim 1 further comprising:

10. 10. The pack of claim 9, wherein the first material composition is substantially similar to the second material composition.

11. 10. The pack of claim 9, wherein the first material composition, the second material composition, and the third material composition are different from each other.

12. 10. The pack of claim 9, wherein the first material composition comprises yttrium and oxygen, the second material composition comprises aluminum and nitrogen, and the third material composition comprises aluminum and oxygen.

13. 2. The pack of claim 1, wherein the first material composition has a first average particle size and the second material composition has a second average particle size different from the first average particle size.

14. A pack for an electrostatic chuck, comprising: A substrate; a first material composition within the substrate; a second material composition within the substrate; and a compositional gradient between the first material composition and the second material composition; Equipped with a pack.

15. The puck of claim 14 , wherein the compositional gradient is between a top surface and a bottom surface of the substrate.

16. The puck of claim 14 , wherein the compositional gradient extends radially from a center of the substrate to an edge of the substrate.

17. The pack of claim 14 , wherein the compositional gradient is an asymmetric compositional gradient.

18. 1. An electrostatic chuck comprising: A base plate; A puck adhered to the base plate, the puck comprising: A substrate; a first material composition within the substrate; a second material composition within the substrate; and a compositional gradient between the first material composition and the second material composition; Pack includes: The electrostatic chuck comprises:

19. 20. The electrostatic chuck of claim 18, further comprising an electrode embedded in the substrate.

20. 20. The electrostatic chuck of claim 18, wherein the substrate has a top surface formed with a mesa.

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