Patent ID: 7208423
Filing Date: 2007-04-24
Classification: G03F,H01L

Abstract:
1. A semiconductor device fabrication method comprising: forming a work film on or above a semiconductor substrate that has selected and non-selected regions, the work film covering the selected and non-selected regions; depositing a mask material over the work film to cover the selected and non-selected regions; forming a first resist pattern on the mask material by forming a first resist material over the mask material, the first resist material having a different composition than the mask material, and patterning the first resist material by a first exposure step to create the first resist pattern, such that the first resist pattern covers the selected and non-selected regions; etching the mask material to form a mask pattern that covers the selected and non-selected regions, using the first resist pattern as an etching mask; removing the first resist material including the first resist pattern; forming a second resist pattern over the mask material by forming a second resist material over the mask material and patterning the second resist material by a second exposure step to create the second resist pattern, such that the second resist pattern covers the non-selected region while leaving a region of the mask pattern that covers the selected region substantially free of the second resist material; slimming selectively a portion of the mask pattern that covers the selected region; removing the second resist material including the second resist pattern; and etching the work film, using the mask material as an etching mask, to form simultaneously a first feature covering the non-selected region and a second feature covering the selected region, the second feature having a width dimension that is smaller than a width dimension of the first feature.