Patent ID: 6440862
Filing Date: 2002-08-27
Classification: H01L

Abstract:
A method of forming a hole in a substrate, the method comprising the acts of:(a) forming a lower layer of photoresist over the substrate; (b) forming an upper layer of photoresist over the lower layer of photoresist; (c) exposing the lower layer of photoresist and the upper layer of photoresist using a single photomask; (d) forming a first opening in the upper layer of photoresist and forming a second opening in the lower layer of photoresist using a single development step; (e) etching a first portion of the substrate through the first opening and the second opening to form a first hole in the substrate having a first width; and (f) etching a second portion of the substrate through at least the second opening to form a second hole in the substrate having a second width, the second width being greater than the first width.