Patent ID: 9651869
Date: 2017-05-16
CPC Classifications: G03F,H01L

Claim:
1. A method for preparing a wafer, comprising: forming a film layer on a substrate of the wafer; coating the film layer with a first photoresist layer; exposing a first portion of the first photoresist layer to a first beam of light, thereby causing a cross-link reaction on the first portion of the first photoresist layer and converting the first portion of the first photoresist layer to a reacted first portion of the first photoresist layer, the reacted first portion of the first photoresist layer adjacent to an edge of the wafer, a second portion of the first photoresist layer being on the film layer separated from the edge of the wafer; removing the second portion of the first photoresist layer; coating the film layer and the first reacted portion of the first photoresist layer with a second photoresist layer; exposing a first portion of the second photoresist layer, over the reacted first portion of the first photoresist layer, to a second beam of light, to form a reacted first portion of the second photoresist layer; exposing a portion of the reacted first portion of the second photoresist layer and a second portion of the second photoresist layer, being directly on the film layer, to a third beam of light, thereby converting the second portion of the second photoresist layer to a patterned second portion of the second photoresist layer; and patterning the film layer based on the reacted first portion of the first photoresist layer and the patterned second portion of the second photoresist layer.