MASK BLANK AND MAKING METHOD

摘要

In a mask blank comprising a transparent substrate and a single layer or multilayer film formed thereon, the film is formed only on the front surface of the substrate, but not on the side surface, chamfer, front surface-chamfer boundary, and back surface-chamfer boundary. The mask blank contains few particle defects, especially the number of particle defects with a certain size is zero.

主权项

1. A mask blank comprising a substrate which is transparent to exposure light, the substrate having a front surface, back surface, side surface, and chamfer, and a film formed on the substrate and consisting of a single layer or plural layers, the single layer or each of plural layers being selected from an optical functional film and a processing aid film,
wherein the film is formed only on the front surface of the substrate, but not on the side surface, the chamfer, the boundary between the front surface and the chamfer, and the boundary between the back surface and the chamfer.