Pattern structure and exposure method of patterned sapphire substrate mask

Abstract

A pattern structure of a photomask for a patterned sapphire substrate (PPS) and an exposure method are disclosed. The pattern structure is formed by stitching a plurality of identical polygons each including at least two sector-shaped opaque areas (7) and one transparent area (2). The polygons are joined together by stitching the sector-shaped opaque areas (7) into round opaque areas (1). Boundary areas of the photomask that are unable to accommodate a complete one of the polygons are configured as opaque areas (1). This pattern structure ensures that the round opaque areas (1) near the frames will not be affected by lighting conditions. During the exposure of another identical PSS photomask pattern, it only needs to superimpose it with the first photomask pattern at their frames to allow the part other than the frame to be exposed. In this way, the photomask pattern and exposure method solves the problem of blurred pattern image edges arising from excessively narrow gaps between photomask frames and opaque areas (1).

Dependencies are inferred from the claim text.