Patent ID: 8431456

Claim:
A method of forming high density structures and low density structures with a single photomask, comprising: utilizing the photomask to pattern narrow masking elements and wide masking elements over a substrate; forming a layer of polymeric material across the narrow masking elements and wide masking elements; the polymeric material being formed to be thicker over the wide masking elements than over the narrow masking elements; anisotropically etching the polymeric material to remove the polymeric material from over the narrow masking elements while leaving the polymeric material remaining over the wide masking elements; the anisotropic etching forming paired sidewall spacers along the narrow masking elements; removing the narrow masking elements to leave the paired sidewall spacers as first masks corresponding to high density structure patterns, and to leave the wide masking elements and polymeric material along the wide masking elements as second masks corresponding to low density structure patterns; and utilizing the first and second masks to pattern high density structures and low density structures within the substrate.