US 12,105,413 B2
Reflective mask blank, reflective mask, method of manufacturing reflective mask, and method of manufacturing semiconductor device
Yohei Ikebe, Tokyo (JP); and Tsutomu Shoki, Tokyo (JP)
Assigned to HOYA CORPORATION, Tokyo (JP)
Filed by HOYA CORPORATION, Tokyo (JP)
Filed on Oct. 9, 2023, as Appl. No. 18/483,484.
Application 18/483,484 is a continuation of application No. 17/990,163, filed on Nov. 18, 2022, granted, now 11,815,807.
Application 17/990,163 is a continuation of application No. 17/056,676, granted, now 11,550,215, issued on Jan. 10, 2023, previously published as PCT/JP2019/020635, filed on May 24, 2019.
Claims priority of application No. 2018-100363 (JP), filed on May 25, 2018; and application No. 2018-165248 (JP), filed on Sep. 4, 2018.
Prior Publication US 2024/0036458 A1, Feb. 1, 2024
Int. Cl. G03F 1/32 (2012.01); G03F 1/24 (2012.01)
CPC G03F 1/32 (2013.01) [G03F 1/24 (2013.01)] 20 Claims
 
1. A reflective mask blank comprising:
a substrate;
a multilayer reflective film on the substrate; and
a phase shift film on the multilayer reflective film,
wherein
the phase shift film comprises a first layer and a second layer,
the first layer comprises at least one selected from tantalum (Ta) and chromium (Cr), and
the second layer comprises ruthenium (Ru),
the phase difference of the phase shift film is 130 degrees to 160 degrees or 200 degrees to 230 degrees,
the refractive index n to EUV light is 0.930 to 0.960 and the extinction coefficient k to EUV light is 0.025 to 0.046 when the phase difference of the phase shift film is 130 degrees to 160 degrees, and
the refractive index n to EUV light is 0.930 to 0.960 and the extinction coefficient k to EUV light is 0.015 to 0.036 when the phase difference of the phase shift film is 200 degrees to 230 degrees.