# US 2014/0154615 A1 · Method for etching euv material layers utilized to form a photomask > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154615 A1 - Document ID: US20140154615A1 - Status: Published application - Kind: A1 - Application number: 13/750,888 - Filed: 2013-01-25 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Applied Materials, Inc. - Inventors: Keven Yu; Medhavi Chandrachood; Amitabh Sabharwal; Ajay Kumar - Web page: https://patentgrep.com/patent/US20140154615A1 ## CPC - G03F 1/00: Originals for photomechanical production of textured or patterned surfaces, e.g., masks, photo-masks, reticles; Mask blanks or pellicles therefor; Containers specially adapted therefor; Preparation thereof - G03F 1/22: Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof - G03F 1/80: Etching - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) ## Abstract A method and apparatus for etching photomasks are provided herein. In one embodiment, a method of etching an ARC layer or an absorber layer disposed on a photomask includes transferring a film stack into an etching chamber, the film stack having an ARC layer or an absorber layer partially exposed through a patterned layer, providing a gas mixture including at least one fluorine containing gas in to a processing chamber, applying a source RF power to form a plasma from the gas mixture, applying a first type of RF bias power to the substrate for a first period of time, applying a second type of RF bias power away from the substrate for a second period of time, and etching the ARC layer or the absorber layer through the patterned layer in the presence of the plasma. ## Claims ### Claim 1 A method of etching an ARC layer or an absorber layer disposed on a photomask, comprising: transferring a film stack into an etching chamber, the film stack having an ARC layer or an absorber layer partially exposed through a patterned layer; providing a gas mixture including at least one fluorine containing gas in to a processing chamber; applying a source RF power to form a plasma from the gas mixture; applying a first type of RF bias power to the substrate for a first period of time; applying a second type of RF bias power away from the substrate for a second period of time; and etching the ARC layer or the absorber layer through the patterned layer in the presence of the plasma. ### Claim 2 (depends on 1) The method of claim 1, wherein ARC layer or an absorber includes at least one of a tantalum containing layer. ### Claim 3 (depends on 1) The method of claim 1, wherein the substrate including the ARC layer disposed on the absorber layer. ### Claim 4 (depends on 1) The method of claim 1, wherein applying the first type of RF bias power comprises: applying the first type of RF bias power to a substrate support disposed in the processing chamber. ### Claim 5 (depends on 1) The method of claim 1, wherein applying the second type of RF bias power comprises: applying the second type of RF bias power through a chamber wall of the processing chamber to ground. ### Claim 6 (depends on 1) The method of claim 1, wherein a time period ratio of the first period of time to the second period of time is controlled at a ratio between about 1:9 and about 4:1. ### Claim 7 (depends on 1) The method of claim 1, wherein the first and the second type of the RF bias power is applied in pulsed mode. ### Claim 8 (depends on 1) The method of claim 1, wherein the absorber layer is a TaN layer or TaBN layer and the ARC layer is a TaO or TaBO layer. ### Claim 9 (depends on 1) The method of claim 1, wherein applying the source RF power further comprises: providing a plasma source power of between about 50 Watts to about 3000 Watts. ### Claim 10 (depends on 1) The method of claim 1, wherein applying the first type of RF bias power further comprises: providing a first plasma bias power of between about 5 and about 600 Watts. ### Claim 11 (depends on 1) The method of claim 1, wherein applying the second type of RF bias power further comprises: providing a second plasma bias power of between about 5 and about 600 Watts. ### Claim 12 A method of etching an ARC layer or an absorber layer disposed on a photomask, comprising: transferring a film stack into an etching chamber, the film stack having an ARC layer disposed on an absorber layer partially exposed through a patterned photoresist layer; providing a first gas mixture including at least one fluorine containing gas in to a processing chamber; applying a first source RF power to form a plasma from the first gas mixture to etch the ARC layer; applying a first type of RF bias power to the substrate for a first period of time; applying a second type of RF bias power away from the substrate for a second period of time; and etching the ARC layer through the patterned photoresist layer in the presence of the plasma. ### Claim 13 (depends on 12) The method of claim 12, further comprising: providing a second gas mixture including at least one chlorine containing gas in to the processing chamber; applying a second source RF power to form a plasma from the first gas mixture to etch the ARC layer; applying a third type of RF bias power to the substrate for a third period of time; applying a fourth type of RF bias power away from the substrate for a fourth of time; and etching the absorber layer through the patterned photoresist and ARC layer in the presence of the plasma. ### Claim 14 (depends on 13) The method of claim 13, wherein the first RF bias power is higher than the third RF bias power. ### Claim 15 (depends on 13) The method of claim 13, wherein the first RF bias power is higher than the third RF bias power between about 50 percent and about 200 percent. ### Claim 16 (depends on 12) The method of claim 12, wherein the first period of time to the second period of time is controlled at a ratio between about 1:9 and about 4:1. ### Claim 17 (depends on 13) The method of claim 13, wherein the third period of time to the fourth period of time is controlled at a ratio between about 1:9 and about 4:1. ### Claim 18 (depends on 12) The method of claim 12, wherein the first type of RF bias power is applied to a substrate support disposed in the processing chamber and the second type of RF bias power is applied through a chamber wall of the processing chamber to ground. ### Claim 19 (depends on 13) The method of claim 13, wherein the third type of RF bias power is applied to a substrate support disposed in the processing chamber and the fourth type of RF bias power is applied through a chamber wall of the processing chamber to ground. ### Claim 20 (depends on 12) The method of claim 12, wherein the film stack further includes a capping disposed on a multiple reflective material layers disposed between the substrate and the absorber layer. ### Claim 21 A method of etching an ARC layer and an absorber layer disposed on a photomask, comprising: transferring a film stack into an etching chamber, the film stack having an ARC layer disposed on an absorber layer partially exposed through a patterned photoresist layer; providing a first gas mixture including at least one fluorine containing gas in to a processing chamber; applying a first type of RF bias power to the substrate for a first period of time; applying a second type of RF bias power away from the substrate for a second period of time; etching the ARC layer through the patterned photoresist layer in the presence of the plasma; providing a second gas mixture including at least one fluorine containing gas in to the same processing chamber; applying a third type of RF bias power to the substrate for a third period of time; applying a fourth type of RF bias power away from the substrate for a fourth period of time, wherein first RF bias power is higher than the third RF bias power.