Application Of Overlay Modeling And Control With Zernike Polynomials In An HVM Environment

By JawWuk Ju, MinGyu Kim and JuHan Lee of SK Hynix; Jeremy Nabeth, John C. Robinson and Bill Pierson of KLA-Tencor; and Sanghuck Jeon and Hoyoung Heo of KLA-Tencor Korea. Abstract Shrinking technology nodes and smaller process margins require improved photolithography overlay control. Generally, overlay measurement results are modeled with Cartesian polynomial functions for both intra-field... » read more