Patent ID: 6218056
Filing Date: 2001-04-17
Classification: B82Y,G03F,G11B

Abstract:
A method of making a bilayer lift-off mask comprising:providing a substrate;forming a bottom release layer on the substrate;forming a top photoresist layer on the release layer;light exposing the top photoresist layer for patterning the top photoresist layer;developing the top photoresist layer with a first developer to form a patterned top photoresist layer that covers a first portion of the bottom release layer and leaves a second portion of the bottom release layer exposed;after light exposing and developing the top photoresist layer directing an electron beam into the exposed second portion of the bottom release layer and into and through the patterned top photoresist layer into the first portion of the bottom release layer for scissioning the first and second portions of the bottom release layer;developing the first and second portions of the bottom release layer with a second developer for removing the second portion of the release layer and lateral portions of the first portion of the release layer under the patterned top photoresist layer so as to provide undercut portions below the patterned top photoresist layer; andthe second developer being a weaker developer than the first developer.