OVERLAY MARK AND METHOD FOR FORMING THE SAME

摘要

An overlay mark applied to a LELE-type double patterning lithography (DPL) process including a first lithography step, a first etching step, a second lithography step and a second etching step in sequence is described. The overlay mark includes a first x-directional pattern and a first y-directional pattern of a previous layer, second x-directional and y-directional patterns of a current layer defined by the first lithography step, and third x-directional and y-directional patterns of the current layer defined by the second lithography step. The second x-directional patterns and the third x-directional patterns are arranged alternately beside the first x-directional pattern. The second y-directional patterns and the third y-directional patterns are arranged alternately beside the first y-directional pattern.

主权项

1. An overlay mark applied to a double patterning lithography (DPL) process including a first lithography step, a first etching step, a second lithography step and a second etching step in sequence, comprising:
a first x-directional pattern and a first y-directional pattern of a previous layer; a plurality of second x-directional patterns and a plurality of second y-directional patterns of a current layer, defined by the first lithography step; and a plurality of third x-directional patterns and a plurality of third y-directional patterns of the current layer, defined by the second lithography step, wherein the second x-directional patterns and the third x-directional patterns are arranged alternately beside the first x-directional pattern, and the second y-directional patterns and the third y-directional patterns are arranged alternately beside the first y-directional pattern.