| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress variation in phase difference and transmittance even when thin films constituting a blank are amorphous films by combining two thin films in such a way that the refractive indexes of the thin films vary in directions opposite to each other or the film thicknesses of the thin films vary in directions opposite to each other when energy is applied to the thin films. SOLUTION: The blank 10 for a halftone type phase shift mask has a relatively light shielding thin film 3 as a lower layer film on the transparent substrate 1 side and a relatively transparent thin film 2 as an upper layer film or has the reverse structure. The transparent thin film 2 and the light shielding thin film 3 are combined in such a way that the refractive indexes of the thin films 2, 3 vary in directions opposite to each other or the film thicknesses of the thin films 2, 3 vary in directions opposite to each other when the energy of a heat process or the like is applied to the thin films 2, 3. When the variations of the refractive indexes and film thicknesses of the thin films 2, 3 are represented byΔnt,Δna,Δdt andΔda, respectively, and the equationΩ=(nt-1)×Δdt+Δnt×dt-(na-1)×Δda-Δna×da... is established, the thin films 2, 3 are preferably selected so as to satisfy the relation of -5.0<Ω<5.0.</p> |
