# US 2026/0305249 A1 · Porous plug assembly, electrostatic chuck, and plasma etching apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0305249 A1 - Document ID: US20260305249A1 - Status: Published application - Kind: A1 - Application number: 19/142,705 - Filed: 2023-11-29 - Published: 2026-10-01 - Earliest claimed: 2022-12-29 - Assignees: Advanced Micro-Fabrication Equipment Inc. China - Applicants: Advanced Micro-Fabrication Equipment Inc. China - Inventors: Erfei GUO; Taotao ZUO - Web page: https://patentgrep.com/patent/US20260305249A1 ## CPC - H10P 72/722: {Details of electrostatic chucks} - H01J 37/32724: {Temperature} - H10P 72/0421: {for drying etching} - H01J 2237/002: Cooling arrangements - H01J 2237/2007: Holding mechanisms - H01J 2237/334: Etching - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract Disclosed are a porous plug assembly, an electrostatic chuck, and a plasma etching apparatus. The porous plug assembly includes a porous plug body with a porous structure, wherein a gas enters from a bottom surface of the porous plug body, passes through the porous plug body, and flows out from a top surface of the porous plug body; and an insulating dense layer, including a lateral portion and a transverse portion, wherein the lateral portion is formed on a side wall of the porous plug body, and the transverse portion at least extends toward one of a direction away from the porous plug body and a direction close to the porous plug body from a top end of the lateral portion. The transverse portion reduces the risk that a bonding layer is eroded by a plasma. The porous plug assembly further reduces the discharge space and the risk of generating arching. The porous plug assembly further effectively solves the problem that the bonding layer blocks the porous plug body. ## Claims ### Claim 1 A porous plug assembly, comprising: a porous plug body with a porous structure, the porous plug body comprising a top surface, a bottom surface, and a side wall, wherein a gas enters from the bottom surface, passes through the porous plug body, and flows out from the top surface; and an insulating dense layer, comprising a lateral portion and a transverse portion, wherein the lateral portion is disposed on the side wall of the porous plug body and is provided with a top end and a bottom end, the bottom end is coplanar with the bottom surface, and the top end is not lower than the top surface; and the transverse portion at least extends toward one of a direction away from the porous plug body and a direction close to the porous plug body from the top end of the lateral portion, and an upper surface of the transverse portion is coplanar with the top end. ### Claim 2 (depends on 1) The porous plug assembly according to claim 1, wherein the transverse portion at least extends toward the direction close to the porous plug body, and a lower surface of the transverse portion is not higher than the top surface. ### Claim 3 (depends on 2) The porous plug assembly according to claim 2, wherein the lower surface of the transverse portion is coplanar with the top surface and covers a part of the top surface. ### Claim 4 (depends on 2) The porous plug assembly according to claim 2, wherein the lower surface of the transverse portion is lower than the top surface, and an area of the top surface is smaller than an area of the bottom surface. ### Claim 5 (depends on 2) The porous plug assembly according to claim 2, wherein the transverse portion further extends toward the direction away from the porous plug body. ### Claim 6 (depends on 1) The porous plug assembly according to claim 1, wherein an elastic member is disposed at the bottom end of the lateral portion. ### Claim 7 (depends on 1) The porous plug assembly according to claim 1, wherein a porosity of the porous plug body is 30% to 60%. ### Claim 8 (depends on 1) The porous plug assembly according to claim 1, wherein the porous plug body is a porous ceramic, and the dense layer is a ceramic. ### Claim 9 (depends on 1) An electrostatic chuck, comprising: a base, wherein a first through hole is formed in the base, and the porous plug assembly according to claim 1 is disposed in the first through hole; and a dielectric plate, wherein an electrode for generating an electrostatic attraction is disposed in the dielectric plate, an upper surface of the dielectric plate is used to fix a wafer, and a lower surface of the dielectric plate is connected to the base through a bonding layer; and the transverse portion is located between the lower surface of the dielectric plate and the base; and a second through hole axially penetrating through the dielectric plate is formed in the dielectric plate, and the second through is in communication with the first through hole. ### Claim 10 (depends on 9) The electrostatic chuck according to claim 9, wherein the transverse portion at least extends toward a direction away from the porous plug body, and the bonding layer is disposed between the lower surface of the transverse portion and the base. ### Claim 11 (depends on 10) The electrostatic chuck according to claim 10, wherein an upper surface of the base is step-shaped and is provided with a lower first upper surface and a higher second upper surface, and the bonding layer is disposed between the lower surface of the transverse portion and the first upper surface. ### Claim 12 (depends on 9) The electrostatic chuck according to claim 9, wherein an insulating layer is disposed between the bonding layer and the base. ### Claim 13 (depends on 12) The electrostatic chuck according to claim 12, wherein the insulating layer is aluminum oxide. ### Claim 14 (depends on 9) The electrostatic chuck according to claim 9, wherein the bonding layer is disposed between the lateral portion and the base. ### Claim 15 (depends on 9) A plasma etching apparatus, comprising a process chamber, the electrostatic chuck according to claim 9, an upper electrode, a cooling apparatus, and a radio frequency power source, wherein the electrostatic chuck is placed in the process chamber to support a wafer and serves as a lower electrode of the process chamber; the cooling apparatus is in communication with the electrostatic chuck for conveying a cooling gas to the wafer; and the upper electrode and the electrostatic chuck are disposed opposite to each other, and the radio frequency power source is applied to the upper electrode or the electrostatic chuck to generate a radio frequency electric field between the upper electrode and the electrostatic chuck to dissociate a reaction gas into a plasma, so as to etch the wafer.