Patent ID: 8697340
Filing Date: 2014-04-15
Classification: H01L,Y10T

Abstract:
1. A method of forming a semiconductor structure, comprising: forming a target layer on a substrate; forming a multi-layer mask layer comprising a first mask layer and a second mask layer sequentially formed on the target layer, wherein the first mask layer comprises silicon nitride, and the second mask layer comprises titanium, titanium nitride, tantalum, or tantalum nitride; forming a first pattern transfer layer having a plurality of openings on the multi-layer mask layer; forming a second pattern transfer layer in the openings of the first pattern transfer layer; patterning the multi-layer mask layer, using the first pattern transfer layer and the second pattern transfer layer as a mask, so as to form a patterned multi-layer hardmask comprises a patterned first mask layer and a patterned second mask layer; and etching the target layer by the patterned multi-layer hardmask, wherein the patterned multi-layer hardmask comprises the patterned first mask layer and the patterned second mask layer, wherein an etch selectivity of the first mask layer to the second mask layer is greater than about 10, an etch selectivity of the second mask layer to the first pattern transfer layer is greater than about 5, and an etch selectivity of the target layer to the first mask layer is greater than about 3.