Patent ID: 7323276
Filing Date: 2008-01-29
Classification: C03C,G03F

Abstract:
1. A photomask blank comprising: a substrate; and an opaque layer provided thereon, the photomask blank used for preparing a photomask for display device manufacturing by patterning the opaque layer, wherein the substrate comprises: a first surface and a second surface, said first surface opposite to said second surface, an edge surface, and chamfered surfaces, said chamfered surfaces being formed between the first surface and the edge surface, and between the second surface and the edge surface, respectively, wherein said substrate has a square shape having each side length of at least 300 mm and a weight of 1 to 15 Kg, and said edge surface and the chamfered surfaces have roughened surfaces having a surface roughness (Ra) of 0.03 to 0.3 micrometer.