# US 11,440,159 B2 · Edge load ring > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,159 B2 - Document ID: US11440159B2 - Status: Granted - Kind: B2 - Application number: 17/034,541 - Filed: 2020-09-28 - Published: 2022-03-31 - Granted: 2022-09-13 - Earliest claimed: 2020-09-28 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Uday Pai; Jeonghoon Oh; Van H. Nguyen - Web page: https://patentgrep.com/patent/US11440159B2 ## CPC - B24B 37/32: Retaining rings - B24B 37/30: for single side lapping of plane surfaces - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS ## Abstract Apparatus and methods relating to chemical mechanical polishing (CMP) are described herein. An edge load ring (ELR) is configured to fit inside a retaining ring of a CMP head. The ELR includes an annular body having an inner surface and an outer surface opposite the inner surface, the outer surface having a diameter configured to slip inside a retaining ring. The annular body includes a body portion formed from a first material and a bottom projection extending below the body portion. The bottom projection has a bottom surface facing away from the body portion, and the bottom projection is formed form a second material different from the first material. The annular body includes a venting feature formed through the annular body, the venting feature being in fluid communication between the inner and outer surfaces. ## Claims ### Claim 1 An edge load ring (ELR) configured to fit inside a retaining ring of a chemical mechanical polishing (CMP) head, the ELR comprising: an annular body including: an inner surface; an outer surface opposite the inner surface, the outer surface having a diameter configured to slip inside the retaining ring; a body portion; a bottom projection extending below the body portion, the bottom projection having a bottom surface facing away from the body portion, the bottom surface configured to contact a substrate; and a venting feature formed through the annular body, the venting feature being in fluid communication between the inner and outer surfaces. ### Claim 2 (depends on 1) The ELR of claim 1, wherein the body portion and the bottom projection are separately formed and coupled together, wherein the body portion comprises a metal, and wherein the bottom projection comprises a plastic. ### Claim 3 (depends on 2) The ELR of claim 2, wherein the bottom projection is coupled to the body portion using at least one of an adhesive or a plurality of fasteners. ### Claim 4 (depends on 1) The ELR of claim 1, wherein the body portion and the bottom projection are integrally formed. ### Claim 5 (depends on 1) The ELR of claim 1, wherein the bottom projection comprises a plurality of projections. ### Claim 6 (depends on 1) The ELR of claim 1, wherein: the body portion is formed from a first material; the bottom projection is formed from a second material different from the first material; and the first material has a first hardness, and wherein the second material has a second hardness less than the first hardness. ### Claim 7 (depends on 1) The ELR of claim 1, wherein the venting feature comprises: a slot formed in the inner surface; and a passage extending radially through the annular body from the slot to the outer surface. ### Claim 8 (depends on 7) The ELR of claim 7, wherein a longitudinal axis of the slot is orthogonal to the bottom surface, and wherein a longitudinal axis of the passage is orthogonal to the longitudinal axis of the slot. ### Claim 9 (depends on 7) The ELR of claim 7, wherein the slot is formed in the inner surface of the body portion without extending to a portion of the inner surface along the bottom projection. ### Claim 10 (depends on 7) The ELR of claim 7, wherein the slot has a width of about 60 mil or less. ### Claim 11 (depends on 1) The ELR of claim 1, wherein the venting feature is formed in the bottom projection without extending to the body portion, and wherein the venting feature extends through the bottom surface. ### Claim 12 (depends on 1) The ELR of claim 1, wherein the venting feature is formed in the bottom projection without extending to the body portion, and wherein the venting feature extends through the inner surface without extending to the bottom surface. ### Claim 13 An edge load ring (ELR) configured to fit inside a retaining ring of a chemical mechanical polishing (CMP) head, the ELR comprising: an annular body including: an inner surface having a step configured to retain the annular body within the polishing head; an outer surface opposite the inner surface, the outer surface having a diameter configured to slip inside the retaining ring; a bottom surface extending between the inner and outer surfaces, the bottom surface configured to contact a substrate disposed in the polishing head; an inner taper extending from the inner surface to the bottom surface; an outer taper extending from the outer surface to the bottom surface; and a venting feature extending between the inner and outer surfaces. ### Claim 14 (depends on 13) The ELR of claim 13, wherein the venting feature is configured to be in fluid communication with a sealed volume formed between the substrate, the inner surface, and a membrane in contact with the inner surface. ### Claim 15 (depends on 13) The ELR of claim 13, wherein the annular body further comprises: a body portion, wherein the body portion is formed from a first material having a first hardness, the first material having a tensile modulus of about 2,500 MPa or greater; and a bottom projection extending below the body portion, wherein the bottom projection is formed from a second material having a second hardness less than the first hardness. ### Claim 16 (depends on 15) The ELR of claim 15, wherein the bottom surface is configured to contact a back side of the substrate, wherein the first hardness is greater than a hardness of the back side, and wherein the second hardness is equal to or less than the hardness of the back side. ### Claim 17 (depends on 15) The ELR of claim 15, wherein the body portion and the bottom projection are separately formed and coupled together, wherein the first material comprises a metal, and wherein the second material comprises a plastic. ### Claim 18 A polishing head, comprising: a housing; a retaining ring coupled to the housing; a membrane coupled to the housing inside the retaining ring, the membrane and the retaining ring forming a substrate-receiving pocket; and an edge load ring (ELR) disposed radially between the membrane and the retaining ring, the ELR including an annular body, the annular body having: an inner surface having a step configured to retain the annular body within the polishing head; an outer surface opposite the inner surface, the outer surface having a diameter configured to slip inside the retaining ring; a bottom surface extending between the inner and outer surfaces, the bottom surface configured to contact a substrate disposed in the substrate-receiving pocket, wherein the substrate extends radially to the retaining ring; and a venting feature extending between the inner and outer surfaces. ### Claim 19 (depends on 18) The polishing head of claim 18, wherein the venting feature comprises: a slot formed in the inner surface; and a passage extending radially through the annular body from the slot to the outer surface. ### Claim 20 (depends on 18) The polishing head of claim 18, wherein the annular body further comprises: a body portion, wherein the body portion is formed from a first material having a first hardness; and a bottom projection extending below the body portion, wherein the bottom projection is formed from a second material having a second hardness less than the first hardness, wherein the venting feature is formed in the bottom projection without extending to the body portion, and wherein the venting feature extends through the bottom surface.