Patent ID: 7579120
Filing Date: 2009-08-25
Classification: G03F

Abstract:
1. A reticle substrate comprising a pair of main surfaces opposing each other, two pairs of side faces that are right to the main surfaces and that are opposed in pair to each other, and chamfered surfaces between the main surfaces and the side faces, wherein: at least one of the main surfaces has a flatness not greater than 0.5 μm on a flatness measuring area which is laid inside of an intermediate area of 3 mm located within a boundary between the at least one main surface and the chamfered surface; the boundary between the at least one main surface and the chamfered surface has a maximum height between −1 and 0 μm (excluding 0 μm) from a reference surface determined in relation to the flatness measuring area disposed inside of the intermediate area; and the intermediate area between the flatness measuring area and the chamfered surface is declined or lowered from the flatness measuring area towards the chamfered surface.