COMPOUND IMAGING METROLOGY TARGETS

摘要

Imaging metrology targets and methods are provided, which combine 1D elements designed to provide one-dimensional (1D) imaging metrology signals along at least two measurement directions and 20 elements designed to provide at least one two-dimensional (2D) imaging metrology overlay signal. The target area of the 1D elements may enclose the 2D elements or the target areas of the 1D and 2D elements may be partially or fully congruent. The compound targets are small, possible multilayered, and may be designed to be process compatible (e.g., by segmentation of the elements, interspaces between elements and element backgrounds) and possibly be produced in die. 2D elements may be designed to periodic to provide additional one dimensional metrology signals.