Patent ID: 9507251
Filing Date: 2016-11-29
CPC Classification: G03B,G03F

Claim Text:
1. A method for manufacturing a reflective mask comprising a substrate, a reflection layer formed on a major surface of the substrate, the reflection layer including a first layer and a second layer, the first layer including molybdenum, the second layer including silicon, the first layer and the second layer being alternately stacked, an absorption layer formed on the reflection layer, a pattern region formed in the absorption layer, the method comprising: forming a light blocking region surrounding the pattern region in the absorption layer and the reflection layer; and the forming the light blocking region including etch-processing both the first layer and the second layer using a gas containing chlorine atom, oxygen atom, and fluorine atom, and an additive amount of a gas including the oxygen atom being set not less than 5 vol % and not more than 30 vol %, and an additive amount of the gas containing fluorine atom to a gas containing chlorine atom being set not less than 5 vol % and not more than 40 vol % in the forming the light blocking region.