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AssigneesUlvac Coating Corporation, Mitsubishi Denki Kabushiki Kaisha
InventorsTakaei Sasaki, Noriyuki Harashima, Satoshi Aoyama, Shouichi Sakamoto
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A chromium-containing half-tone phase-shift photomask comprising coarse and dense patterns coexisting in a plane is prepared by a series of pattern-forming steps including forming a resist layer on a photomask blank, exposing and patterning said resist layer, developing, etching said photomask blank and removing said resist layer. Patterns for transferring onto a wafer are formed on the photomask blank by a dry-etching method comprising dry-etching a chromium-containing half-tone phase-shift film utilizing etching gas comprised of mixed gas including (a) reactive ion etching gas, containing an oxygen-containing gas and a halogen-containing gas, and (b) reducing gas added to the gas component (a).
A chromium-containing half-tone phase-shift photomask comprising coarse and dense patterns coexisting in a plane which is prepared by performing a series of pattern-forming steps including a step for forming a resist layer on a photomask blank, a step for exposing and patterning said resist layer, a developing step, a step for etching said photomask blank and a step for removing said resist layer, wherein the photomask is characterized in that patterns to be transferred onto a wafer are formed on said photomask blank for the chromium-containing half-tone phase-shift photomask according to a dry-etching method comprising dry-etching a chromium-containing half-tone phase-shift film utilizing an etching gas comprised of a mixed gas including (a) a reactive ion etching gas, which contains an oxygen-containing gas and a hydrogen chloride gas, and (b) a reducing gas added to the gas component (a).
Dependencies are inferred from the claim text.