Patent ID: 7737016
Filing Date: 2010-06-15
Classification: G03F,H01L

Abstract:
1. A method of forming a semiconductor device, comprising: defining a plurality of first features and at least one ghost feature on a photosensitive layer by exposing a first mask to a light, wherein the first mask comprises a plurality of phase shift areas that change a phase of the light; removing by a first etch a first portion of a layer disposed under the photosensitive layer to form the plurality of first features and the at least one ghost feature; following the first etch, defining one or more structures not requiring phase shifting on the photosensitive layer by exposing a second mask to the light, wherein the second mask removes the at least one ghost feature; and removing by a second etch a second portion of the layer disposed under the photosensitive layer to form one or more structures not requiring phase shifting, wherein the second portion comprises the at least one ghost feature.