Patent ID: 7969580

Claim:
A method for step-and-align interference lithography, comprising the steps of: (a) providing a carrier capable of moving in a first axial direction and a second axial direction as well as rotating about the same; (b) providing an interference light beam while detecting a displacement error of the interference light beam relating to the moving of the carrier; (b1) disposing a position sensor on the carrier; (b2) projecting a first beam of the interference light beam on the position sensor while forming a lighting area thereon and registering a first position relating to the lighting area; (b3) controlling the carrier to move a specific distance along the first axial direction while registering a second position relating to a lighting area being formed by projecting a second beam of the interference light beam on the position sensor; (b4) calculating a position difference between the first and the second position with respect to the second axial direction; and (b5) calculating the ratio between the position difference and the specific distance so as to obtain the displacement error basing upon the obtained ratio; (c) enabling the interference light beam to project on a workpiece mounted on the carrier for forming a specific interference-patterned region on the workpiece; (d) performing a position adjustment according to the displacement error in a stepwise manner so as to prepare the workpiece for a next formation of interference-patterned region; and (e) repeating the execution of the step (c) to step (d) for multiple times so as to form a large-area interference pattern by stitching the so-generated interference-patterned regions together.