Patent ID: 9252061
Filing Date: 2016-02-02
CPC Classification: G03F,H01L

Claim Text:
1. A method comprising: determining a size and a shape of an overlay mark; determining a size and a shape of an overlay mark protection zone based on the shape of the overlay mark; determining a shape of a plurality of dummy structures based on the shape of the overlay mark, wherein one of the plurality of dummy structures is aligned at each corner of the overlay mark protection zone; determining a size and a shape of at least one active layer zone based on the size and the shape of the overlay mark and the plurality of dummy structures; forming the at least one active layer zone in an active layer of a semiconductor substrate; forming the overlay mark and the plurality of dummy structures over the at least one active layer zone in a polysilicon (poly) layer of the semiconductor substrate; and planarizing the poly layer.