# US 10,373,853 B2 · Electrostatic chuck and wafer processing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,853 B2 - Document ID: US10373853B2 - Status: Granted - Kind: B2 - Application number: 15/534,798 - Filed: 2015-12-10 - Published: 2018-09-13 - Granted: 2019-08-06 - Earliest claimed: 2014-12-10 - Assignees: Toto Ltd. - Applicants: Toto Ltd. - Inventors: Kazuki Anada; Yuichi Yoshii - Web page: https://patentgrep.com/patent/US10373853B2 ## CPC - H10P 72/722: {Details of electrostatic chucks} - H10P 72/0432: {mainly by conduction} - H10P 72/0434: {mainly by convection} - H10P 72/0602: {Temperature monitoring} - H10P 72/72: using electrostatic chucks - B23B 31/28: using electric or magnetic means in the chuck - Y10T 279/23: with magnetic or electrostatic means - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - B23B: TURNING; BORING (arrangements for copying or controlling B23Q) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electrostatic chuck includes a ceramic dielectric substrate having a first major surface on which an object to be processed is mounted, and a second major surface, the ceramic dielectric substrate being a polycrystalline ceramic sintered body, an electrode layer provided on the ceramic dielectric substrate, a base plate provided on a side of the second major surface and supporting the ceramic dielectric substrate, and a heater provided between the electrode layer and the base plate. The base plate includes a through hole piercing the base plate and a communication path passing a medium adjusting a temperature of the object to be processed, and when viewed in a direction perpendicular to the first major surface, at least a part of the heater exists on a side of the through hole as viewed from a first portion of the communication path which is closest to the through hole. ## Claims ### Claim 1 An electrostatic chuck comprising: a ceramic dielectric substrate having a first major surface on which an object to be processed is mounted, and a second major surface on a side opposite to the first major surface, the ceramic dielectric substrate being a polycrystalline ceramic sintered body; an electrode layer provided on the ceramic dielectric substrate; a base plate provided on a side of the second major surface and supporting the ceramic dielectric substrate; and a heater provided between the electrode layer and the base plate, the base plate having a through hole piercing a portion thereof, the base plate further having a communication path formed internally therein for passing a medium for adjusting a temperature of the object to be processed, and wherein, when viewed in a direction perpendicular to the first major surface, at least a part of the heater is disposed between the through hole and a first portion of the communication path which is closest to the through hole, said part of the heater having a shape which encloses a portion of the through hole, and a part of the communication path, which includes the first portion, has a shape which encloses said portion of the through hole. ### Claim 2 (depends on 1) The electrostatic chuck according to claim 1, wherein when viewed in the direction perpendicular to the first major surface, a distance between the first portion and a center axis of the through hole is larger than a distance between a second portion of the heater which is closest to the through hole and the center axis of the through hole. ### Claim 3 (depends on 2) The electrostatic chuck according to claim 2, wherein when viewed in the direction perpendicular to the first major surface, a distance between a center of a first virtual circle passing the first portion and any two portions on the side of the through hole of the communication path and a center of a second virtual circle passing the second portion and any two portions on the side of the through hole of the heater is not more than 0.2 millimeters. ### Claim 4 (depends on 2) The electrostatic chuck according to claim 2, wherein when viewed in the direction perpendicular to the first major surface, a center of a first virtual circle passing the first portion and any two portions on the side of the through hole of the communication path overlaps a center of a second virtual circle passing the second portion and any two portions on the side of the through hole of the heater. ### Claim 5 (depends on 2) The electrostatic chuck according to claim 2, wherein when viewed in the direction perpendicular to the first major surface, a width of the communication path in the first portion is wider than a width of the heater in the second portion. ### Claim 6 (depends on 3) The electrostatic chuck according to claim 3, wherein when viewed in the direction perpendicular to the first major surface, a length of a portion where the second virtual circle crosses the heater is not less than 50 percent and not more than 80 percent of a length of circle perimeter of the second virtual circle. ### Claim 7 (depends on 1) The electrostatic chuck according to claim 1, wherein the heater includes: a first heater having a first folded-back portion bent from a first direction to a second direction different from the first direction, and a second heater having a second folded-back portion provided to be close to the first heater and bent from a third direction to a fourth direction different from the third direction, and wherein a distance of closest approach between the first folded-back portion and the second folded-back portion is between 50 percent and 100 percent of a distance between a round end portion of the first folded-back portion and a round end portion of the second folded-back portion. ### Claim 8 (depends on 1) The electrostatic chuck according to claim 1, wherein when viewed in the direction perpendicular to the first major surface, a ratio of an area of the heater to an area of the ceramic dielectric substrate is not less than 20% and not more than 80%. ### Claim 9 (depends on 1) The electrostatic chuck according to claim 1, wherein when viewed in the direction perpendicular to the first major surface, a ratio of an area of the communication path to an area of the ceramic dielectric substrate is not less than 20% and not more than 80%. ### Claim 10 (depends on 1) The electrostatic chuck according to claim 1, wherein when viewed in the direction perpendicular to the first major surface, a ratio of an area of the heater to an area of the communication path is not less than 60% and not more than 180%. ### Claim 11 (depends on 1) The electrostatic chuck according to claim 1, further comprising a plurality of bypass electrodes provided between the electrode layer and the base plate and electrically connected to the heater, wherein a distance between mutually adjacent bypass electrodes of the plurality of bypass electrodes is not less than 0.05 millimeters and not more than 10 millimeters. ### Claim 12 (depends on 1) The electrostatic chuck according to claim 1, further comprising a plurality of bypass electrodes provided between the electrode layer and the base plate and electrically connected to the heater, wherein a length along the direction perpendicular to the first major surface of a region between mutually adjacent bypass electrodes of the plurality of bypass electrodes is not less than 0.01 millimeters and not more than 1 millimeter. ### Claim 13 (depends on 1) A wafer processing apparatus comprising the electrostatic chuck according to claim 1.