Patent ID: 6830702
Filing Date: 2004-12-14
Classification: C03C,C23F,G03F

Abstract:
A method for fabricating a single-trench alternating phase shift mask (PSM) comprising:patterning an opaque layer over a mask layer over a transparent layer of the PSM according to a semiconductor design; first dry etching the mask layer and the transparent layer through a photoresist layer applied over the opaque layer after the opaque layer has already been patterned according to the semiconductor design, the photoresist layer patterned according to an alternating PSM design, the first dry etching through the patterned photoresist layer initially forming single trenches of the PSM within the mask layer and the transparent layer according to the alternating PSM design; wet etching the transparent layer through the mask layer as has been dry etched to completely form the single trenches of the PSM, the photoresist layer having first been removed; and, second dry etching die mask layer, the single trenches of the PSM initially filled with filler material to protect the single trenches from the second dry etching, the filler material subsequently removed.