CERAMIC ENGINEERING BY GRADING MATERIALS
20230312422 · 2023-10-05
Inventors
Cpc classification
C04B2235/3225
CHEMISTRY; METALLURGY
H02N13/00
ELECTRICITY
International classification
H02N13/00
ELECTRICITY
Abstract
Embodiments disclosed herein include a puck for an electrostatic chuck. In an embodiment, the puck comprises a substrate with a top surface and a bottom surface. In an embodiment, a first material composition is at the top surface of the substrate, and a second material composition is at the bottom surface of the substrate. In an embodiment, a composition gradient is provided through the substrate between the top surface and the bottom surface.
Claims
1. A puck for an electrostatic chuck, comprising: a substrate with a top surface and a bottom surface; a first material composition at the top surface of the substrate; a second material composition at the bottom surface of the substrate; and a composition gradient through the substrate between the top surface and the bottom surface.
2. The puck of claim 1, wherein the first material composition comprises up to and including 100% of a first solid solution phase, and wherein the second material composition comprises up to and including 100% of a second solid solution phase.
3. The puck of claim 2, wherein the first solid solution phase comprises Al.sub.2O.sub.3, and wherein the second solid solution phase comprises AlN.
4. The puck of claim 2, wherein the first solid solution phase comprises AlN, and wherein the second solid solution phase comprises Al.sub.2O.sub.3.
5. The puck of claim 1, wherein the first material composition comprises a first solid solution phase and a second solid solution phase, and wherein the second material composition comprises the first solid solution phase and the second solid solution phase, wherein a percentage of the second solid solution phase in the second material composition is less than a percentage of the second solid solution phase in the first material composition.
6. The puck of claim 1, wherein 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. The puck of claim 1, wherein a metal oxide comprises one or more of aluminum, copper, molybdenum, tungsten, and graphite.
8. The puck of claim 7, wherein the metal comprises 0.01% or more of the material composition.
9. The puck of claim 1, further comprising: a third material composition between the first material composition and the second material composition, wherein the composition gradient comprises a first grading between the first material composition and the third material composition and a second grading between the third material composition and the second material composition.
10. The puck of claim 9, wherein the first material composition is substantially similar to the second material composition.
11. The puck of claim 9, wherein the first material composition, the second material composition, and the third material composition are different from each other.
12. The puck of claim 9, wherein the first material composition comprises yttrium and oxygen, wherein the second material composition comprises aluminum and nitrogen, and wherein the third material composition comprises aluminum and oxygen.
13. The puck of claim 1, wherein the first material composition has a first average grain size, and wherein the second material composition has a second average grain size that is different than the first average grain size.
14. A puck for an electrostatic chuck, comprising: a substrate; a first material composition in the substrate; a second material composition in the substrate; and a composition gradient between the first material composition and the second material composition.
15. The puck of claim 14, wherein the composition gradient is between a top surface and a bottom surface of the substrate.
16. The puck of claim 14, wherein the composition gradient extends out radially from a center of the substrate to an edge of the substrate.
17. The puck of claim 14, wherein the composition gradient is an asymmetric composition gradient.
18. An electrostatic chuck, comprising: a base plate; and a puck adhered to the base plate, wherein the puck comprises: a substrate; a first material composition in the substrate; a second material composition in the substrate; and a composition gradient between the first material composition and the second material composition.
19. The electrostatic chuck of claim 18, further comprises an electrode embedded in the substrate.
20. The electrostatic chuck of claim 18, wherein a mesa is fabricated into a top surface of the substrate.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
[0009]
[0010]
[0011]
[0012]
[0013]
[0014]
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
DETAILED DESCRIPTION
[0025] 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 in order to provide a thorough understanding of embodiments. It will be apparent to one skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known aspects are not described in detail in order to not unnecessarily obscure embodiments. Furthermore, it is to be understood that the various embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.
[0026] As noted above, semiconductor processing tools typically employ a chuck in order to secure the 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 over the base plate. In the case of an electrostatic chuck, the puck will also include electrodes in order to provide an electrostatic charge that secures the substrate to the chuck. The puck is generally a ceramic material.
[0027] There are several design considerations to take into account when selecting the material of the puck. Chucking strength, temperature uniformity, and resistance to etching chemistries are some design considerations that may be used in the design of the puck. Unfortunately, the design considerations may result in a chuck that is optimized for one application, while sacrificing performance in other areas. This is especially true when the puck is formed from a single material, as is commonly the case in existing architectures.
[0028] An example of a chuck 150 is provided in
[0029] Accordingly, embodiments disclosed herein include pucks that have multiple material compositions. For example, a first surface of the puck may have a first material composition, and a second surface of the puck may have a second material composition. Additionally, there may be a compositional gradient between the first material composition and the second material composition. That is, embodiments may include a puck that has a continuously changing material composition through a thickness of the puck, or a changing material composition in a radial direction. Other compositional gradient directions may also be used in some embodiments.
[0030] The puck materials may include ceramic-ceramic gradients, ceramic-metal gradients, ceramic-polymer gradients, or metal-polymer gradients. In a particular embodiment, the ceramic materials may include metal oxides, nitrides, carbides, borides, fluorides, silicides, sulfides, or the like. In the case of metal oxides, the metal component may include aluminum, copper, molybdenum, tungsten, titanium, graphite, or the like.
[0031] Referring now to
[0032] In an embodiment, the substrate 230 may comprise a first material composition 231 at a top surface and a second material composition 232 at a bottom surface. Additionally, a compositional gradient 235 may be provided between the first material composition 231 and the second material composition 232. That is, a material composition of the substrate 230 may change through a thickness of the puck 220. More particularly, the embodiment shown in
[0033] 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 compositional gradient 235 may start with one material and end with a second material. In one embodiment, the first solid solution phase may include 100% Al.sub.2O.sub.3 and the second solid solution phase may include 100% AlN. The compositional gradient 235 may change from an Al.sub.2O.sub.3 rich material composition at a top of the substrate 230 to an AlN rich material composition at a bottom of the substrate 230. For example, at a midpoint between the first material composition 231 and the second material composition 232, the compositional gradient 235 may have approximately 50% Al.sub.2O.sub.3 and approximately 50% AlN. Of course, it is to be appreciated that the compositional gradient 235 may not be linear. For example, the location where the compositional gradient 235 has approximately 50% Al.sub.2O.sub.3 and approximately 50% AlN may be closer to either the first material composition 231 or closer to the second material composition. In an embodiment, a percentage of one of the material compositions may be monotonically increasing through the thickness of the substrate 230.
[0034] In an additional embodiment, the first material composition 231 and the second material composition 232 may include two distinct solid solution phases. For example, the first material composition 231 may include approximately 70% Al.sub.2O.sub.3 and approximately 30% AlN. In some instances, the second material composition 232 may include approximately 100% AlN. In other embodiments, the second material composition 232 may comprise approximately 70% AlN and approximately 30% Al.sub.2O.sub.3. 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 with a pair of solid solution phases to a second material composition with a pair of solid solution phases.
[0035] In the case of an Al.sub.2O.sub.3 and AlN substrate 230, the Al.sub.2O.sub.3 rich top material composition 231 will provide an increase in the clamp force at higher operating temperatures. The AlN has a higher thermal conductivity, and will improve the temperature uniformity of the puck 220.
[0036] While the first material composition 231 and the second material composition 232 are described as being metal oxides and metal nitrides, it is to be appreciated that other material classes may also 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, or the like. Additionally, metal materials may also be used, such as aluminum, copper, molybdenum, tungsten, titanium, graphite, or the like.
[0037] Referring now to
[0038] For example, the first material composition 231 may comprise AlN, and the second material composition 232 may comprise Al.sub.2O.sub.3. Such an embodiment may result in improved heat conduction at higher plasma loads, and an increase in the clamp force. The clamp force may increase as a result of a decrease in the effective electrical distance. Additionally, housing the electrodes 221 in the Al.sub.2O.sub.3 controls the charge transports and improves performance of the puck 220.
[0039] In
[0040] Referring now to
[0041] In an embodiment, 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 greater detail above. For example, the first material composition 333 may comprise Al.sub.2O.sub.3, and the second material composition 334 may comprise AlN. Though, it is to be appreciated that the first material composition 333 and the second material composition 334 may be reversed. Additionally, the first material composition 333 and the second material composition 334 may comprise two solid solution phases in some embodiments. In an embodiment, a solid solution phase is monotonically increasing in the radial direction. In other embodiments, a linear increase in a solid solution phase is provided along the composition gradient 335.
[0042] Referring now to
[0043] In an embodiment, 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 greater detail above. For example, the first material composition 336 may comprise Al.sub.2O.sub.3, and the second material composition 337 may comprise AlN. Though, it is to be appreciated that the first material composition 336 and the second material composition 337 may be reversed. Additionally, the first material composition 336 and the second material composition 337 may comprise two solid solution phases in some embodiments. In an embodiment, a solid solution phase is monotonically increasing across the substrate 330. In other embodiments, a linear increase in a solid solution phase is provided along the composition gradient 335.
[0044] In the embodiments described above, a pair of material compositions are provided in the puck. However, it is to be appreciated that embodiments may include two or more different material compositions.
[0045] Referring now to
[0046] In some embodiments, the first material composition 431 and the second material composition 432 comprise the same material, and the third material composition 438 comprises a different material composition. For example, the first material composition 431 and the second material composition 432 may comprise Al.sub.2O.sub.3, and the third material composition 438 may comprise AlN. Compositional gradient 435A may be provided between the first material composition 431 and the third material composition 438, and compositional gradient 435B may be provided between the third material composition 438 and the second material composition 432.
[0047] In an embodiment, the third material composition 438 may be provided at a midpoint between the first material composition 431 and the second material composition 438. In other embodiments, a distance between the third material composition 438 and the first material composition 431 may be different than a 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.
[0048] Referring now to
[0049] 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 may comprise the same material. By including the same material at the interface, lower stresses (due to coefficient of thermal expansion (CTE) mismatch) are provided. While shown with a diffusion bonded interface, it is to be appreciated that embodiments may also include an adhesive bond between the second material composition 432 and the base plate 451.
[0050] Referring now to
[0051] Referring now to
[0052] 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 may comprise the same material. By including the same material at the interface, lower stresses (due to CTE mismatch) are provided. While shown with a diffusion bonded interface, it is to be appreciated that embodiments may also include an adhesive bond between the second material composition 432 and the base plate 451.
[0053] Referring now to
[0054] Referring now to
[0055] Referring now to
[0056] Referring now to
[0057] In an embodiment, 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. That is, the residual portion of the first material composition may be removed (e.g., with a grinding or polishing process) after the diffusion process.
[0058] Referring now to
[0059] Referring now to
[0060] In
[0061] Referring now to
[0062] It is to be appreciated that the compositional gradients described herein can take the form of various material property variations. For example, compositional gradients described herein may refer to changes to one or more of material type, particle size, crystallite size, porosity, and material attribute (e.g., CTE, Young's modulus, Poisson ratio, thermal conductivity, hardness, resistivity, etc.).
[0063] Additionally, it is to be appreciated that embodiments described herein can be fabricated using various processes. For example, green sheet lamination, hot press, cold isostatic press, field assisted sintering, electrophoretic deposition, laser sintering, 3D printing, solgel, gel cast, or combinations thereof may be used to form pucks with a compositional gradient. In some embodiments, the entire ceramic body can be co-sintered or sintered in multiple steps. The sintering temperatures may range from between 20° C. and 2,000° C. In some embodiments, the grading can be accomplished during the sintering process by changing the ambient gas composition (e.g., changing O.sub.2 gas, changing partial pressures, changing species of the gas, or the like). Raw material powder sizes can vary from approximately 1 nm to up to approximately 500 μm. In an embodiment, the ceramic material may be piezoelectric (e.g., AlN, PZT, BaTiO.sub.3 based, SrTiO.sub.3 templates, or the like). In other embodiments, the ceramic material may be piezoresistive. The thickness of the substrate for the pucks may range from between approximately 0.1 mm and approximately 20 mm.
[0064] Referring now to
[0065] Computer system 1000 may include a computer program product, or software 1022, having a non-transitory machine-readable medium having stored thereon instructions, which may be used to program computer system 1000 (or other electronic devices) to perform a process 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, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.
[0066] 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.
[0067] System processor 1002 represents one or more general-purpose processing devices such as a microsystem processor, central processing unit, or the like. More particularly, the system processor may be a complex instruction set computing (CISC) microsystem processor, reduced instruction set computing (RISC) microsystem processor, very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or system processors implementing a combination of instruction sets. 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), network system processor, or the like. System processor 1002 is configured to execute the processing logic 1026 for performing the operations described herein.
[0068] 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 unit 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 generation device 1016 (e.g., a speaker).
[0069] The secondary memory 1018 may include a machine-accessible storage medium 1032 (or more specifically a computer-readable storage medium) on which is stored 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 execution thereof by the computer system 1000, 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 a network 1020 via the system network interface device 1008. In an embodiment, the network interface device 1008 may operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling.
[0070] While the machine-accessible storage medium 1032 is shown in an exemplary embodiment to be a single medium, the term “machine-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies. The term “machine-readable storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media.
[0071] In the foregoing specification, specific exemplary embodiments have been described. It will be evident that various modifications may be made thereto without departing from the scope of the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.