Mask for extreme ultraviolet lithography and method for manufacturing same

A method for manufacturing a mask for extreme ultraviolet lithography, the method comprising:

• preparing a pre-reflective structure including a plurality of unit layers laminated on a substrate and an etch stop layer placed between one pair of adjoining unit layers among plurality of unit layers;
• etching the pre-reflective structure to manufacture a reflective structure having a trench through which the etch stop layer is exposed;
• and
• forming an absorption pattern on a bottom surface of the trench,
• wherein the etch stop layer includes SiO2,
• a thickness of the etch stop layer is 5.45 nm to 6.6 nm, and
• the number of the plurality of unit layers disposed under the etch stop layer is controlled to be in the range of 10 to 20,
• wherein the preparing of the pre-reflective structure comprises:
• a first lamination step including forming a first material layer on the substrate and forming a second material layer on the first material layer;
• forming the etch stop layer on the second material layer;
• and
• a second lamination step including forming the first material layer on the etch stop layer and forming the second material layer on the first material layer,
• wherein the first lamination step and the second lamination step are repeated a plurality of times,
• wherein the first material layer includes molybdenum and the second material layer includes silicon, and
• a thickness of the first material layer is 3.5 nm to 4.9 nm and a thickness of the second material layer is 2.1 nm to 3.5 nm,
• wherein the forming of the etch stop layer comprises a step of thermally oxidizing the uppermost second material layer in the first lamination step, which is performed first among the plurality of the first lamination step,
• wherein the thickness of the uppermost second material layer before the thermal oxidation is performed in the first lamination step is larger than the thickness of the second material layer that is not thermally oxidized, and
• wherein the thickness of the uppermost second material layer after the thermal oxidation is performed is the same as the thickness of the second material layer that is not thermally oxidized.