Patent ID: 8058175
Filing Date: 2011-11-15
Classification: G02F

Abstract:
1. A method for planarization of a top metal layer used as a mirror of LCOS on which an insulating oxide layer having a recess is formed, comprising: forming an etching-resist layer over the insulating oxide layer to fill the recess, the thickness of the etching-resist layer in the recess being larger than that outside the recess; etching without performing CMP the etching-resist layer and the insulating oxide layer, wherein, the etching speed of the insulating oxide layer is higher than that of the etching-resist layer, so that the insulating oxide layer outside the recess is not higher than the bottom of the recess; removing the etching-resist layer in the recess; and etching the insulating oxide layer till the top metal layer is exposed completely, wherein the insulating oxide layer is etched till the top metal layer is completely exposed by a dry etching process, for achieving flatness of the top metal layer and avoiding concentric ring recesses caused by CMP on the top metal layer.