# US 10,770,330 B2 · Wafer contact surface protrusion profile with improved particle performance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,330 B2 - Document ID: US10770330B2 - Status: Granted - Kind: B2 - Application number: 16/073,648 - Filed: 2017-02-02 - Published: 2019-02-28 - Granted: 2020-09-08 - Earliest claimed: 2016-02-10 - Assignees: Entegris, Inc. - Applicants: ENTEGRIS, Inc. - Inventors: John Michael Glasko; I-Kuan Lin; Carlo Waldfried - Web page: https://patentgrep.com/patent/US10770330B2 ## CPC - H10P 72/722: {Details of electrostatic chucks} - H10P 72/72: using electrostatic chucks - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract An electrostatic chuck with a generally non-arcuate top surface shaped protrusions that has edge surfaces similar to a portion of a ellipse. The structure of the protrusions leads to the reduction of particulate material generated by interaction between the supported substrate and chuck. Reduced levels of scratching, abrasion, wear and particulate generation are achieved by improved smoothing and flattening of the protrusion surface. ## Claims ### Claim 1 An electrostatic chuck comprising: an electrode in a ceramic base; and a surface layer of the electrostatic chuck activated by a voltage in the electrode to form an electric charge that electrostatically clamps a substrate to the electrostatic chuck; wherein the surface layer of the electrostatic chuck comprises a plurality of protrusions, the protrusions comprising a composition whose morphology is columnar or granular, and whose microstructure is crystalline or amorphous, the protrusions extending to an average height H above the surface layer surrounding the protrusions, the protrusions supporting the substrate upon the protrusions during electrostatic clamping of the substrate; a cross section of the protrusions has a structure characterized by a non-arcuate plateau shaped top surface, an edge surface, and a side surface; wherein the non-arcuate plateau shaped top surface of the protrusions has a length L in microns that is characterized by a flatness parameter Δ in microns, the top surface having a surface roughness Ra of 1 micron or less and a value of (Δ*100)/L that is less than ±0.01; the edge surface of the protrusion is between the top surface and the side surface of the protrusion and has an edge surface profile that lies on or within a quadrant or portion thereof of an ellipse, the minor axis Y of the ellipse intersecting a portion of the top surface of the protrusion wherein the value of (Δ*100)/L is equal to or greater than ±0.01, and the minor axis apex of the ellipse lying along the top surface of the protrusion, the value of Y/2 is 0.5 microns or less; the major axis X of the ellipse is substantially parallel to the top surface or surface layer of the protrusion and the value of X/2 is between 25 microns and 250 microns; and the side surface of the protrusions connects the edge surface and the surface layer of the electrostatic chuck. ### Claim 2 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise a material that is softer than silicon. ### Claim 3 (depends on 1) The electrostatic chuck of claim 1, where the protrusion side surface makes an angle with the surface layer, wherein the angle is between 80 degrees and 175 degrees. ### Claim 4 (depends on 1) The electrostatic chuck of claim 1 further comprising a gas seal ring or lift pin seal that extends to an average height H above the surface layer; wherein a cross section of the gas seal ring or lift pin seal has a structure characterized by a non-arcuate plateau shaped top surface, an edge surface, and a side surface; wherein the non-arcuate plateau shaped top surface of the gas seal ring or lift pin seal has a length L in microns that is characterized by a flatness parameter Δ in microns, the top surface having a surface roughness Ra of 1 micron or less and a value of (Δ*100)/L that is less than ±0.01; the edge surface of the gas seal ring or lift pin seal is between the top surface and the side surface of the gas seal ring or lift pin seal and has an edge surface profile that lies on or within a quadrant or portion thereof of an ellipse, the minor axis Y of the ellipse intersecting a portion of the top surface of the gas seal ring or lift pin seal wherein the value of (Δ*100)/L is equal to or greater than ±0.01, and the minor axis apex of the ellipse lying along the top surface of the gas seal ring or lift pin seal, the value of Y/2 is 0.5 microns or less; the major axis X of the ellipse is substantially parallel to the top surface of the gas seal ring or lift pin seal and the value of X/2 is between 25 microns and 250 microns; and the side surface of the gas seal ring or lift pin seal connects the edge surface and the surface layer. ### Claim 5 (depends on 4) The electrostatic chuck of claim 4, wherein Δ value of 0.25 microns or less. ### Claim 6 (depends on 1) The electrostatic chuck of claim 1, wherein Δ has a value of 0.25 microns or less. ### Claim 7 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise yttrium. ### Claim 8 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise aluminum. ### Claim 9 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise aluminum and oxygen. ### Claim 10 (depends on 9) The electrostatic chuck of claim 9, wherein the protrusions comprise aluminum oxynitride. ### Claim 11 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise yttria. ### Claim 12 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise alumina. ### Claim 13 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise yttrium aluminum garnet. ### Claim 14 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions a height in the range of 5 microns to 20 microns. ### Claim 15 (depends on 1) The electrostatic chuck of claim 1, wherein Δ has a value of between 0.25 microns and 0.05 microns. ### Claim 16 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions have a center to center distance of between 1 micron and 20 microns. ### Claim 17 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise a coating overlying a ceramic. ### Claim 18 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise a composition having a columnar morphology as determined by scanning electron microscopy. ### Claim 19 (depends on 1) The electrostatic chuck of claim 1, wherein the protrusions comprise a composition having a crystalline morphology as measured by x-ray diffraction. ### Claim 20 A wafer contact surface comprising: a plurality of protrusions, the protrusions comprising a composition whose morphology is columnar or granular, and whose microstructure is crystalline or amorphous, the protrusions extending to an average height H above the surface layer surrounding the protrusions, the protrusions supporting a wafer upon the protrusions during clamping of the wafer; a cross section of the protrusions having a structure characterized by a non-arcuate plateau shaped top surface, an edge surface, and a side surface; wherein the non-arcuate plateau shaped top surface of the protrusions has a length L in microns that is characterized by a flatness parameter Δ in microns, the top surface having a surface roughness Ra of 1 micron or less and a value of (Δ*100)/L that is less than ±0.01; wherein the edge surface of the protrusion is between the top surface and the side surface of the protrusion has an edge surface profile that lies on or within a quadrant or portion thereof of an ellipse, the minor axis Y of the ellipse intersecting an edge of the flat surface of the protrusion wherein the value of (Δ*100)/L is equal to or greater than ±0.01, and the minor axis apex of the ellipse lying along the top surface of the protrusion, the value of Y/2 is 0.5 microns or less; the major axis X of the ellipse is substantially parallel to the top surface of the protrusion and the value of X/2 is between 25 microns and 250 microns; and the side surface of the protrusions connects the edge surface and a surface layer of the wafer contact surface.