US 12,135,496 B2
Reflective mask blank and reflective mask
Yohei Ikebe, Tokyo (JP); Tsutomu Shoki, Tokyo (JP); Takahiro Onoue, Tokyo (JP); and Hirofumi Kozakai, Tokyo (JP)
Assigned to HOYA CORPORATION, Tokyo (JP)
Filed by HOYA CORPORATION, Tokyo (JP)
Filed on Dec. 1, 2023, as Appl. No. 18/526,463.
Application 18/526,463 is a continuation of application No. 17/946,709, filed on Sep. 16, 2022, granted, now 11,880,130.
Application 17/946,709 is a continuation of application No. 17/227,655, filed on Apr. 12, 2021, granted, now 11,480,867, issued on Oct. 25, 2022.
Application 17/227,655 is a continuation of application No. 16/490,018, granted, now 11,003,068, issued on May 11, 2021, previously published as PCT/JP2018/006054, filed on Feb. 20, 2018.
Claims priority of application No. 2017-040043 (JP), filed on Mar. 3, 2017; and application No. 2017-107394 (JP), filed on May 31, 2017.
Prior Publication US 2024/0103354 A1, Mar. 28, 2024
Int. Cl. G03F 1/24 (2012.01); G03F 1/26 (2012.01)
CPC G03F 1/24 (2013.01) [G03F 1/26 (2013.01)] 20 Claims
 
1. A reflective mask blank comprising:
a substrate;
a multilayer reflective film formed above the substrate; and
a phase shift film formed above the multilayer reflective film,
wherein the phase shift film comprises an alloy having at least two metal elements, the at least two metal elements including at least one metal element from a Group A and at least one metal element from a Group B,
wherein:
(i) the metal elements in the Group A are Pd, Ag, Pt, Au, Ir, W, Cr, Co, Mn, Sn, Ta, V, Fe and Hf, and the metal elements in the Group B are Rh, Ru, Mo, Nb, Ti, Zr, Y and Si;
(ii) the metal elements in the Group A are Ag, Pt, Au, Ir, W, Cr, Co, Mn, Sn, Ta, Fe and Hf, and the metal elements in the Group B are Pd, Rh, Ru, Mo, Nb, V, Ti, Zr, Y and Si; or
(iii) the metal elements in the Group A are Rh, Pd, Ag, Pt, Au, Ir, W, Cr, Co, Mn, Sn, Ta, V, Ti, Fe and Hf, and the metal elements in the Group B are Ru, Mo, Nb, Zr, Y and Si,
wherein the phase shift film has a composition ratio so that a phase difference θ is in a range of θ0−2 degrees≤θ≤θ0+2 degrees when a prescribed phase difference is defined as θ0 with respect to wavelength of 13.5 nm, and a reflectance R is in a range of R0−0.2%≤R≤R0+0.2% when a prescribed reflectance is defined as R0 with respect to wavelength of 13.5 nm.