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CN-122028694-A - Electrostatic chuck with gradient porosity and segmented electrode and manufacturing method and application thereof

CN122028694ACN 122028694 ACN122028694 ACN 122028694ACN-122028694-A

Abstract

The application belongs to the technical field of semiconductor equipment manufacturing, and particularly relates to an electrostatic chuck with gradient porosity and a segmented electrode structure, and a preparation method and application thereof. The electrostatic chuck comprises a substrate, a first dielectric layer, a second dielectric layer and an electrode layer, wherein the substrate, the first dielectric layer and the second dielectric layer are sequentially arranged from bottom to top, the electrode layer is formed in the first dielectric layer, the porosity of the first dielectric layer is less than or equal to 2%, the porosity of the second dielectric layer is 10-15%, the electrode layer comprises a center electrode layer and an edge electrode layer surrounding the center electrode layer, and the dielectric material electrically isolates the center electrode layer from the edge electrode layer. The electrostatic chuck adopts a gradient porosity structure and a sectional electrode structure in the vertical direction, so that the temperature uniformity of a substrate is improved, the desorption time is shortened, and the throughput of equipment is improved.

Inventors

  • LI GANG
  • WANG BIAO

Assignees

  • 匠郢精密陶瓷(苏州)有限公司

Dates

Publication Date
20260512
Application Date
20260130

Claims (10)

  1. 1. An electrostatic chuck, comprising a substrate, a first dielectric layer, a second dielectric layer, and an electrode layer completely embedded in the first dielectric layer, which are sequentially arranged from bottom to top, The porosity of the first dielectric layer is less than or equal to 2%, and the porosity of the second dielectric layer is 10-15%; the electrode layers include a center electrode layer and an edge electrode layer surrounding the center electrode layer, wherein a dielectric material electrically isolates the center electrode layer from the edge electrode layer.
  2. 2. The electrostatic chuck of claim 1, wherein the second dielectric layer has a porosity of 10-12%.
  3. 3. The electrostatic chuck of claim 1, further comprising a surface functional layer on a side of the second dielectric layer remote from the first dielectric layer, wherein the surface functional layer has a thickness of 0.5-2 μm, the surface functional layer is a composite coating comprising Al 2 O 3 and Y 2 O 3 , the Al 2 O 3 is 90-97mol% and the Y 2 O 3 is 3-10mol%.
  4. 4. The electrostatic chuck of claim 1, wherein the first dielectric layer and the second dielectric layer are each an aluminum oxide ceramic or an aluminum nitride ceramic, and the sum of the thicknesses of the first dielectric layer and the second dielectric layer is 1.0-2.0mm, and wherein the thickness of the first dielectric layer is 60-70% of the sum of the thicknesses of the first dielectric layer and the second dielectric layer.
  5. 5. The electrostatic chuck of claim 1, further comprising an edge ground ring disposed about the periphery of the first dielectric layer and the second dielectric layer.
  6. 6. A method of manufacturing an electrostatic chuck according to any one of claims 1 to 5, comprising the steps of: S1, preparing a matrix; s2, preparing slurry: preparing a first dielectric layer slurry; Preparing a second dielectric layer slurry; preparing electrode layer slurry; S3, molding Casting the first dielectric layer slurry to obtain a first dielectric layer green sheet, casting the second dielectric layer slurry to obtain a second dielectric layer green sheet, superposing at least one first dielectric layer green sheet and at least one second dielectric layer green sheet, and performing cold isostatic pressing to obtain a composite green sheet, wherein the electrode layer slurry is printed on at least one first dielectric layer green sheet before superposition; S4, sintering Baking the composite green body to obtain a composite layer containing the first dielectric layer, the second dielectric layer and the electrode layer; s5, connecting the composite layer with a substrate to obtain the electrostatic chuck.
  7. 7. The method of claim 6, wherein the first dielectric layer paste in step S2 is prepared by mixing 80-120 parts by weight of ceramic powder, 0.2-0.4 part by weight of sintering aid, 0.3-0.5 part by weight of dispersant, 2-4 parts by weight of plasticizer and 3-5 parts by weight of binder.
  8. 8. The method of claim 6, wherein the second dielectric layer paste in step S2 is prepared by mixing 80-120 parts by weight of ceramic powder, 0.2-0.4 part by weight of sintering aid, 12-18 parts by weight of pore-forming agent, 0.3-0.5 part by weight of dispersant, 2-4 parts by weight of plasticizer and 3-5 parts by weight of binder.
  9. 9. The method of claim 8, wherein the pore former comprises 10-20wt% of the ceramic powder by weight.
  10. 10. Use of an electrostatic chuck according to any one of claims 1 to 5 or an electrostatic chuck obtainable by a method according to any one of claims 6 to 9 in the semiconductor field.

Description

Electrostatic chuck with gradient porosity and segmented electrode and manufacturing method and application thereof Technical Field The invention belongs to the technical field of semiconductor equipment manufacturing, and particularly relates to an electrostatic chuck with gradient porosity and a segmented electrode structure, and a preparation method and application thereof. Background In the semiconductor manufacturing process, the electrostatic chuck, also called electrostatic chuck (Electrostatic Chuck, ESC), is a key component that uses electrostatic force to attract and fix a substrate (such as a semiconductor wafer) on its surface, and provides a stable, flat and mechanical stress-free support platform for the substrate in processes such as etching, deposition or photolithography, and the performance of the electrostatic chuck is directly related to the uniformity, stability and production efficiency of the process. However, the existing electrostatic chuck has significant drawbacks in maintaining substrate temperature uniformity and desorption rate, and has become one of the bottlenecks restricting the development of advanced semiconductor processes, mainly represented by: First, existing thermal management solutions for electrostatic chucks tend to be passive and homogenous in many ways, which rely on simple bonding of cooling fluid channels or heating elements to a homogenous substrate, resulting in limited thermal diffusivity throughout the chuck body. When there is a local temperature difference in the substrate, the heat cannot be rapidly and effectively redistributed in the chuck plane to compensate for the difference, so that it is difficult to overcome the inherent thermal gradient caused by the process itself, the environment or the equipment structure, which directly affects the chemical reaction rate, the film growth thickness, the doping uniformity and the uniformity of critical dimensions, and finally leads to fluctuation of the product performance and reduction of the yield. Second, in order to obtain a strong and reliable chucking force, existing electrostatic chucking chucks tend to pursue extremely low porosity and near perfect densification of the dielectric layer. This design, while effective during the adsorption phase, constitutes a fundamental obstacle during the release phase. When the high voltage applied to the electrode is cut off, the release of the vacuum state is only dependent on the extremely slow natural diffusion or leakage of the gas through the microscopic slits, since the closed space formed between the substrate and the surface of the dielectric layer of the chuck is difficult to be filled rapidly with the external gas. This results in a lengthy desorption process, typically up to several seconds or even longer. In summary, the design of the existing electrostatic chuck has a contradiction that is difficult to reconcile in terms of controlling the substrate temperature uniformity and desorption rate, and the high densification measure adopted to enhance the adsorption stability just worsens the uniformity of heat transfer and the efficiency of gas exchange, thereby limiting the desorption rate. Therefore, how to improve the uniformity of the substrate temperature control and the desorption rate at the same time, so as to improve the yield of the product and meet the application in the prior process has become a key technical problem to be solved in the field. Disclosure of Invention Therefore, the technical problem to be solved by the invention is to provide an electrostatic chuck which can simultaneously improve the uniformity of the substrate temperature and the desorption rate, thereby improving the yield of products and being suitable for more advanced (for example, 5nm and below) processes. In order to solve the above technical problems, the present inventors have intensively studied and found that the use of a dielectric layer having a gradient porosity structure in a vertical direction and a segmented electrode structure can make the heat conduction efficiency tend to be uniform in a full substrate range and significantly shorten the desorption time. Aiming at the technical problems, the invention provides the following technical scheme: in a first aspect, the present application provides an electrostatic chuck comprising a substrate, a first dielectric layer, and a second dielectric layer disposed in sequence from bottom to top, and an electrode layer fully embedded in the first dielectric layer, wherein, The porosity of the first dielectric layer is less than or equal to 2%, and the porosity of the second dielectric layer is 10-15%; the electrode layers include a center electrode layer and an edge electrode layer surrounding the center electrode layer, wherein a dielectric material electrically isolates the center electrode layer from the edge electrode layer. In some embodiments of the application, the second dielectric layer has a porosity of 10-12%.