Reflective mask blank for EUV lithography
AssigneeAsahi Glass Company, Limited
InventorKazuyuki Hayashi
Life of this patent
Estimating the term…
Abstract
A reflective mask blank for EUV lithography having an absorbing layer which has a low reflectivity with respect to wavelength regions of EUV light and pattern inspection light, and which is easily controllable to obtain desired film composition and film thickness. The reflective mask blank for EUV lithography having a reflective layer for reflecting EUV light and an absorbing layer for absorbing EUV light which are formed in this order on a substrate, wherein the absorbing layer contains at least tantalum (Ta), boron (B), nitrogen (N) and hydrogen (H), and the absorbing layer has a B content that is 1 at % or greater but less than 5 at %, an H content that is between 0.1 and 5 at %, a Ta+N total content that is between 90 and 98.9%, and a Ta:N composition ratio (Ta:N) that is between 8:1 and 1:1.
Claims37
A reflective mask blank for EUV lithography having a reflective layer for reflecting EUV light and an absorbing layer for absorbing EUV light which are formed in this order on a substrate,
- the reflective mask blank for EUV lithography being characterized in that the absorbing layer contains at least tantalum (Ta), boron (B), nitrogen (N) and hydrogen (H), and
- the absorbing layer has a B content that is 1 at % or greater but less than 5 at %, an H content that is between 0.1 and 5 at %, a Ta+N total content that is between 90 and 98.9 at %, and a Ta:N composition ratio (Ta:N) that is between 8:1 and 1:1.
A reflective mask blank for EUV lithography having a reflective layer for reflecting EUV light and an absorbing layer for absorbing EUV light which are formed in this order on a substrate,
- the reflective mask blank for EUV lithography being characterized in that the absorbing layer contains at least tantalum (Ta), boron (B), nitrogen (N) and hydrogen (H), and
- the absorbing layer is, in its crystalline state, amorphous.
A reflective mask blank for EUV lithography having a reflective layer for reflecting EUV light, an absorbing layer for absorbing EUV light and a low reflective layer with respect to inspection light which is used for inspecting a mask pattern, which are formed in this order on a substrate
- the reflective mask blank for lithography being characterized in that,
- the low reflective layer contains at least tantalum (Ta), boron (B), oxygen (O) and hydrogen (H), and
- the low reflective layer has a B content that is 1 at % or greater but less than 5 at %, an H content that is between 0.1 and 15 at %, a Ta+O total content that is between 80 and 98.9 at %, and a Ta:O composition ratio (Ta:O) that is between 1:8 and 3:1.
A reflective mask blank for EUV lithography having a reflective layer for reflecting EUV light, an absorbing layer for absorbing EUV light and a low reflective layer with respect to inspection light which is used for inspecting a mask pattern, which are formed in this order on a substrate,
- the reflective mask blank for lithography being characterized in that
- the low reflective layer contains at least tantalum (Ta), boron (B), oxygen (O), nitrogen (N) and hydrogen (H), and
- the low reflective layer has a B content that is 1 at % or greater but less than 5 at %, an H content that is between 0.1 and 15 at %, a Ta+O+N total content that is between 80 and 98.9 at % and a Ta:O+N composition ratio (Ta:(O+N)) that is between 1:8 and 3:1.
Dependencies are inferred from the claim text.