Patent ID: 11880130
Assignee: HOYA CORPORATION
Field: Optics (Instruments)
Classification: CPC G  C | IPC G

Claim 0:
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 the metal elements in the Group A are Pd, Ag, Pt, Au, Ir, W, Cr, Mn, Sn, V, Fe and Hf,
wherein the metal elements in the Group B are Rh, Ru, Mo, Nb, Zr and Y, and
wherein the phase shift film has a refractive index of approximately between 0.877 to 0.940 and an extinction coefficient of approximately between 0.014 to 0.052 for wavelength of 13.5 nm.