	US 11,815,807 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 Nov. 18, 2022, as Appl. No. 17/990,163.
Application 17/990,163 is a continuation of application No. 17/056,676, granted, now 11,550,215, 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 2023/0087016 A1, Mar. 23, 2023
Int. Cl. G03F 1/32 (2012.01); G03F 1/24 (2012.01)

CPC G03F 1/32 (2013.01) [G03F 1/24 (2013.01)]

19 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) and at least one selected from chromium (Cr), nickel (Ni), cobalt (Co), vanadium (V), niobium (Nb), molybdenum (Mo), tungsten (W), and rhenium (Re), and

a refractive index n of the second layer for EUV light is 0.860 to 0.950 and an extinction coefficient k of the second layer for EUV light is 0.008 to 0.095.