Reflective mask blank for euv lithography
AssigneeAsahi Glass Company, Limited
InventorsKazuyuki Hayashi, Toshiyuki Uno, Ken Ebihara
Life of this patent
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Abstract
A reflective mask blank for EUV lithography is provided which has an absorber layer wherein stress and crystal structure can be easily controlled. A reflective mask blank for EUV lithography, which comprises a substrate, and at least a reflective layer for reflecting EUV light and an absorber layer for absorbing EUV light formed in this order on the substrate, wherein the absorber layer contains tantalum (Ta), nitrogen (N) and hydrogen (H); and in the absorber layer, the total content of Ta and N is from 50 to 99.9 at %, and the content of H is from 0.1 to 50 at %.
Claims24
A reflective mask blank for EUV lithography, comprising:
- a substrate;
- a reflective layer for reflecting EUV light over the substrate;
- and
- an absorber layer for absorbing EUV light formed in this order over the substrate;
- wherein the absorber layer contains tantalum (Ta), nitrogen (N) and hydrogen (H);
- and
- the total content of Ta and N is from 50 to 99.9 at %, and the content of H is from 0.1 to 50 at % in the absorber layer.
A method for producing a reflective mask blank for EUV lithography, comprising:
- forming a reflective layer for reflecting EUV light, over a substrate;
- and then,
- forming an absorber layer over the reflective layer,
- wherein the absorber layer is formed by carrying out a sputtering method employing a Ta target in an atmosphere comprising an inert gas containing at least one member selected from the group consisting of helium (He), argon (Ar), neon (Ne), krypton (Kr) and xenon (Xe), nitrogen (N2) and hydrogen (H2).
Dependencies are inferred from the claim text.