# US 11,309,203 B2 · Wafer stage and method of manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,203 B2 - Document ID: US11309203B2 - Status: Granted - Kind: B2 - Application number: 16/458,264 - Filed: 2019-07-01 - Published: 2020-05-14 - Granted: 2022-04-19 - Earliest claimed: 2019-07-01 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Kazuyuki Tomizawa; Masashi Kikuchi; Michio Ishikawa; Takafumi Noguchi; Kazuhiro Yamamuro - Web page: https://patentgrep.com/patent/US11309203B2 ## CPC - H10P 72/722: {Details of electrostatic chucks} - F25B 21/02: using Peltier effect; using Nernst-Ettinghausen effect - H10N 10/13: characterised by the heat-exchanging means at the junction - H10P 72/0432: {mainly by conduction} - H10P 72/0434: {mainly by convection} - H10P 72/0602: {Temperature monitoring} - H10P 72/72: using electrostatic chucks - H10P 72/7616: {characterised by a coating, a hardness or a material} - F25B 2321/023: Mounting details thereof - F25B 2321/0252: by liquids or two-phase fluids - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A wafer stage includes an electrostatic chuck (ESC) plate, an upper supporting plate, a lower supporting plate and a temperature controller. The ESC plate includes a first surface that supports a wafer. The upper supporting plate is bonded to a second surface of the ESC plate opposite to the first surface. The lower supporting plate overlaps the upper supporting plate. The temperature controller is disposed between the upper supporting plate and the lower supporting plate. The ESC plate includes ceramics. The upper supporting plate includes a composite material of aluminum or aluminum alloy and ceramics or carbon. The ESC plate and the upper supporting plate are directly bonded to each other by a room temperature solid bonding process. Thus, the wafer stage has sufficient strength to withstand pressure differences between a vacuum and atmospheric pressure, improved temperature response by minimizing heat capacity, and prevents warpage of the ESC plate. ## Claims ### Claim 1 A wafer stage comprising: an electrostatic chuck (ESC) plate that includes a first surface on which a wafer is placed; an upper supporting plate bonded to a second surface of the ESC plate opposite to the first surface; a lower supporting plate that overlaps the upper supporting plate; and a temperature controller disposed between the upper supporting plate and the lower supporting plate, wherein the ESC plate comprises a material that includes ceramics, the upper supporting plate comprises a composite material of aluminum or aluminum alloy and ceramics or carbon, and the ESC plate and the upper supporting plate are directly bonded to each other by a room temperature solid bonding process. ### Claim 2 (depends on 1) The wafer stage of claim 1, wherein the ceramics comprises at least one of SiC, Al2O3 or AlN. ### Claim 3 (depends on 1) The wafer stage of claim 1, wherein the composite material of the upper supporting plate has a porosity of no more than 1%. ### Claim 4 (depends on 1) The wafer stage of claim 1, wherein the upper supporting plate has a thermal expansion coefficient of no greater than ±5% of that of the ESC plate. ### Claim 5 (depends on 1) The wafer stage of claim 1, wherein the temperature controller comprises a Peltier element. ### Claim 6 (depends on 5) The wafer stage of claim 5, wherein the Peltier element comprises a plurality of elements, and each of the Peltier elements is independently controlled. ### Claim 7 (depends on 5) The wafer stage of claim 5, wherein the Peltier element occupies an area of no less than about 45% of an area of a first surface of the lower supporting plate. ### Claim 8 (depends on 5) The wafer stage of claim 5, wherein the Peltier element provides the first surface of the ESC plate with a heat change rate of no less than 1° C./sec in a temperature range from 30° C. to 80° C. and a cooling change rate of no less than 0.6° C./sec. ### Claim 9 (depends on 5) The wafer stage of claim 5, further comprising a flexible thermal conductive sheet disposed between the Peltier element and the upper supporting plate. ### Claim 10 (depends on 9) The wafer stage of claim 9, wherein the thermal conductive sheet has a thermal conductivity of no less than about 1 w/mK. ### Claim 11 (depends on 9) The wafer stage of claim 9, wherein the thermal conductive sheet has a thickness from 0.3 mm to 1.0 mm, absent a load to the thermal conductive sheet. ### Claim 12 (depends on 9) The wafer stage of claim 9, wherein the thermal conductive sheet has hardness of no more than Asker C20. ### Claim 13 (depends on 1) The wafer stage of claim 1, wherein the lower supporting plate has a cooling passageway through which a cooling agent flows. ### Claim 14 (depends on 1) The wafer stage of claim 1, wherein the lower supporting plate includes a material that has a Young's Modulus of no less than about 120 MPa. ### Claim 15 (depends on 14) The wafer stage of claim 14, wherein the lower supporting plate comprises at least one of Ti, Ti alloy, carbon, Si, SiC, Al2O3, BN or ZrO2. ### Claim 16 (depends on 1) The wafer stage of claim 1, wherein a total value of a heat capacity from a second surface of the upper supporting plate that faces the temperature controller to the first surface of the ESC plate is no more than 3.0 J/K per unit area. ### Claim 17 (depends on 1) The wafer stage of claim 1, further comprising: a screw that combines the upper supporting plate with the lower supporting plate using a screw; a spacer disposed around the screw to uniformly maintain a gap between the upper supporting plate and the lower supporting plate; and a release-preventing member provided with the screw. ### Claim 18 A method of manufacturing a wafer stage, the wafer stage being an electrostatic chuck (ESC) plate that includes a first surface on which a wafer is placed, an upper supporting plate bonded to a second surface of the ESC plate opposite to the first surface, a lower supporting plate that overlaps the upper supporting plate, and a temperature controller disposed between the upper supporting plate and the lower supporting plate, wherein the ESC plate comprises a material that includes ceramics, and the upper supporting plate comprises a composite material of aluminum or aluminum alloy and ceramics or carbon, the method comprising: forming a middle layer between the ESC plate and the upper supporting plate; and directly bonding the ESC plate to the upper supporting plate using the middle layer by using a room temperature solid bonding process. ### Claim 19 (depends on 18) The method of claim 18, wherein the middle layer comprises at least one of Al, Ti, Ni, Au, Ag, Cu, In, Sn, Si or SiO2. ### Claim 20 A wafer stage comprising: an electrostatic chuck (ESC) plate that includes a first surface on which a wafer is placed; an upper supporting plate bonded to a second surface of the ESC plate opposite to the first surface; a lower supporting plate that overlaps the upper supporting plate; a Peltier element disposed between the upper supporting plate and the lower supporting plate; and a flexible thermal conductive sheet disposed between the Peltier element and the upper supporting plate, wherein the ESC plate and the upper supporting plate are directly bonded to each other by a room temperature solid bonding process.