Patent ID: 6500744
Filing Date: 2002-12-31
Classification: H01L

Abstract:
A method of forming an opening in a substrate, comprising:forming at least two blocks of a first material over a substrate, a pair of the at least two blocks being separated by a gap and comprising sidewall edges; forming spacers of a second material along the sidewall edges, the spacers only partially filling the gap and leaving a remaining portion of the gap unfilled; forming a layer of the first material within the unfilled remaining portion of the gap, the first material of the blocks and the first material within the gap together defining a mask; removing the second material spacers with an etch selective for the second material relative to the first material to form openings extending through the mask; etching the substrate through the openings in the mask to form an opening into the substrate, the method further comprising; before forming the first material blocks, forming a layer of second material over the substrate; forming the first material blocks and the second material spacers over the layer of second material; and etching the layer of second material through the openings in the mask.