Patent ID: 8420305

Claim:
A method for generating periodic patterns by step-and-align interference lithography, comprising steps of: (a) providing at least two coherent light beams with a pattern and a substrate to be exposed; (b) exposing the substrate to the at least two coherent light beams simultaneously so as to form a patterned interference region on the substrate at one of plural exposure shot areas; (c) adjusting a next exposing position stepwisely; and (d) repeating step (b) to step (c) so that another patterned interference region is formed by alternating motions of one stepwise movement of the carrier unit and one shot of exposure of the at least two coherent light beams simultaneously incident on the substrate, wherein the substrate is prevented from being exposed to the at least two coherent light beams when the substrate is moving, until a plural patterned interference regions are formed on the substrate, wherein the patterned interference regions are configured so that the exposure patterns of the patterned interference regions are identical to each other, and wherein a right boundary of each patterned interference region is identical to a left boundary of a corresponding neighboring patterned interference region, or an upper boundary of each patterned interference region is identical to a lower boundary of a corresponding neighboring patterned interference region.