Phase shift mask blank, phase shift mask, and methods of manufacture

摘要

A phase shift mask blank includes a transparent substrate and a phase shift film thereon. The phase shift film is composed primarily of a metal and silicon, typically molybdenum silicide oxide carbide or molybdenum silicide oxide nitride carbide, and has a film stress no higher than 100 MPa. The low stress makes it possible to maintain a good substrate flatness when the phase shift film is formed during production of the phase shift mask blank, and when the phase shift film is patterned during production of a phase shift mask from the blank.