Patent ID: 8233136

Claim:
An apparatus for generating periodic patterns by step-and-align interference lithography, comprising: a light generating unit, capable of generating at least two coherent light beams with a pattern; a carrier unit, capable of carrying a substrate to be exposed to the at least two coherent light beams simultaneously to form a patterned interference region on the substrate at one of plural exposure shot areas; and a driver unit, coupled to the carrier unit to provide a driving force to move the carrier unit stepwisely 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 coherent light beams when the carrier unit is moving, 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.