Sidewall Assisted Process for Wide and Narrow Line Formation

摘要

A method of forming narrow and wide lines includes forming mandrels separated by wider gaps and narrower gaps, forming sidewall spacers on sides of the gaps, and then removing the mandrels. Subsequent anisotropic etching extends through an underlying mask layer at locations between sidewall spacers that were formed in wider gaps, to thereby separate narrow line portions of the mask layer, without extending through the mask layer at locations between sidewall spacers that were formed in narrower gaps, thereby leaving wide line portions of the mask layer under the second sidewall spacers.

主权项

1. A method of forming narrow and wide lines comprising:
forming a mask layer; subsequently forming a plurality of mandrels on an upper surface of the mask layer, the plurality of mandrels including first mandrels separated by first gaps and second mandrels separated by second gaps, the first gaps being wider than the second gaps, wherein an individual first mandrel has a first width and an individual second mandrel has a second width that is less than the first width; subsequently forming first sidewall spacers on sides of the first gaps and forming second sidewall spacers on sides of the second gaps; subsequently removing the plurality of mandrels; subsequently performing anisotropic etching, the anisotropic etching extending through the mask layer at locations between the first sidewall spacers, to thereby separate narrow line portions of the mask layer under the first sidewall spacers, without extending through the mask layer at locations between the second sidewall spacers thereby leaving wide line portions of the mask layer under the second sidewall spacers; and subsequently, patterning an underlying layer using the narrow line portions and the wide line portions.