Patent ID: 7432197
Filing Date: 2008-10-07
Classification: G03F,H01L

Abstract:
1. A method of patterning photoresist, comprising: providing a construction which has an optically saturable absorption layer over a topography with surfaces differing in reflectivity relative to one another; forming the photoresist over the optically saturable absorption layer; directing electromagnetic radiation into the photoresist; some of the directed electromagnetic radiation passing through the photoresist, to the topography, and then reflecting back from the topography to the photoresist; the difference in reflectivity of the surfaces of the topography patterning the reflected electromagnetic radiation; the directed electromagnetic radiation and patterned reflected electromagnetic radiation together exposing a first portion of the photoresist to a threshold dose of radiation while a second portion of the photoresist remains not exposed to the threshold dose; and developing the photoresist to selectively remove either the first or second portion of the photoresist relative to the other of the first and second portions.