| 摘要 |
SOLUTION: There is provided a half tone phase shift mask blank having a half tone phase shift film that is formed on a transparent substrate and is composed of a silicon-based material including silicon and nitrogen, or a silicon-based material including silicon, nitrogen, and oxygen where the content of oxygen is 6 atom% or less, has a refractive index of 2.4 or more, contains a layer having an extinction coefficient k of 0.4 or more and 0.7 or less, and has a film thickness of 67 nm or less.EFFECT: The half tone phase shift mask blank is provided with a half tone phase shift film which is thinner and so favorable for processing a photomask pattern, is excellent in chemical resistance to chemical wash, and secures a phase difference necessary for a phase shift film and a transmittance necessary for a half tone mask. A half tone phase shift mask is also provided.SELECTED DRAWING: Figure 1 |
