# US 12,224,195 B2 · Centering wafer for processing chamber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,195 B2 - Document ID: US12224195B2 - Status: Granted - Kind: B2 - Application number: 17/879,074 - Filed: 2022-08-02 - Published: 2024-02-08 - Granted: 2025-02-11 - Earliest claimed: 2022-08-02 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Muhannad Mustafa; Sanjeev Baluja - Web page: https://patentgrep.com/patent/US12224195B2 ## CPC - H10P 72/50: for positioning, orientation or alignment - B25B 11/005: {Vacuum work holders} - H10P 72/722: {Details of electrostatic chucks} - H10P 72/78: using vacuum or suction, e.g. Bernoulli chucks - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - B25B: TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING ## Abstract Processing chambers, substrate supports, centering wafers and methods of center calibrating wafer hand-off are described. A centering wafer comprises a disc-shaped body having a top surface and a bottom surface defining a thickness, a center, an outer edge having an outer peripheral face, a first arc-shaped slit and a second arc-shaped slit. Embodiments of the disclosure advantageously provide the ability to use the centering wafer to monitor and control backside pressure and thereby determine the center of a substrate support prior to processing the centering wafer. The centering wafer may be centered at a plurality of different angles by rotating the centering wafer. ## Claims ### Claim 1 A centering wafer comprising: a disc-shaped body having a top surface and a bottom surface defining a thickness, a center and an outer edge having an outer peripheral face; and a plurality of arc-shaped slits extending through the thickness of the disc-shaped body, the plurality of arc-shaped slits including a first arc-shaped slit and a second arc-shaped slit, the first arc-shaped slit having a first width defined by an inner edge and an outer edge, the inner edge having an inner face spaced a first distance from the center of the disc-shaped body and shaped concentric to the disc-shaped body, the outer edge having an outer face spaced a second distance from the center of the disc-shaped body and shaped concentric to the disc-shaped body, the second distance being greater than the first distance, the first arc-shaped slit having a first length defined by a first end and a second end, the first end having a first end face, the second end having a second end face, each of the first end and second end located at different angular orientations relative to the center of the disc-shaped body, the first arc-shaped slit spaced a first distance from the outer peripheral face, and the second arc-shaped slit having a second width defined by an inner edge and an outer edge, the inner edge having an inner face spaced a first distance from the center of the disc-shaped body and shaped concentric to the disc-shaped body, the outer edge having an outer face spaced a second distance from the center of the disc-shaped body and shaped concentric to the disc-shaped body, the second distance being greater than the first distance, the second arc-shaped slit having a second length defined by a first end and a second end, the first end having a first end face, the second end having a second end face, each of the first end and second end located at different angular orientations relative to the center of the disc-shaped body, the second arc-shaped slit spaced a second distance from the outer peripheral face, the second arc-shaped slit centered angularly a distance from the first arc-shaped slit greater than the larger of the first width or second width, the first arc-shaped slit and the second arc-shaped slit on opposite sides of the disc-shaped body, wherein the disc-shaped body does not include any other slits other than the first arc-shaped slit and the second arc-shaped slit. ### Claim 2 (depends on 1) The centering wafer of claim 1, wherein each of the first width of the first arc-shaped slit and the second width of the second arc-shaped slit independently comprises a width in a range of from 15 mils to 25 mils. ### Claim 3 (depends on 2) The centering wafer of claim 2, wherein each of the first width of the first arc-shaped slit and the second width of the second arc-shaped slit independently comprises a width of 20 mils. ### Claim 4 (depends on 2) The centering wafer of claim 2, wherein the first width of the first arc-shaped slit is equal to the second width of the second arc-shaped slit. ### Claim 5 (depends on 1) The centering wafer of claim 1, wherein each of the first length of the first arc-shaped slit and the second length of the second arc-shaped slit independently comprises a length of 5 mm to 15 mm. ### Claim 6 (depends on 5) The centering wafer of claim 5, wherein the first length of the first arc-shaped slit is equal to the second length of the second arc-shaped slit. ### Claim 7 (depends on 1) The centering wafer of claim 1, wherein the inner edge, outer edge, first end and second end of each of the first arc-shaped slit and the second arc-shaped slit define an area of each of the first arc-shaped slit and the second arc-shaped slit. ### Claim 8 (depends on 7) The centering wafer of claim 7, wherein the area of each of the first arc-shaped slit and the second arc-shaped slit is in a range of from 10 mm2 to 15 mm2. ### Claim 9 (depends on 8) The centering wafer of claim 8, wherein the area of each of the first arc-shaped slit and the second arc-shaped slit is 12 mm2. ### Claim 10 (depends on 1) The centering wafer of claim 1, wherein each of the first distance and the second distance is in a range of from 50 mils to 150 mils. ### Claim 11 (depends on 1) The centering wafer of claim 1, wherein the thickness of the disc-shaped body is in a range of from 0.75 mm to 2.5 mm. ### Claim 12 (depends on 11) The centering wafer of claim 11, wherein the thickness of the disc-shaped body is 1.5 mm.