Patent ID: 7390749
Filing Date: 2008-06-24
Classification: H01L

Abstract:
1. A method for providing features in an etch layer with a memory region and a peripheral region, where a density of features in the memory region is at least twice a density of features in the peripheral region, comprising: forming first and second sacrificial layers over the etch layer; forming a memory patterned mask over the sacrificial layer, where the memory patterned mask provides features over memory region; etching a first set of sacrificial layer features into the first sacrificial layer and the second sacrificial layer, where the first set of sacrificial layer features are in the memory region; filling features of the first set of sacrificial layer features with filler material; removing the first sacrificial layer, so that parts of the filler material remain exposed above a surface of the second sacrificial layer, wherein spaces are between the exposed parts of the filler material, where the spaces are in an area formerly occupied by the first sacrificial layer, wherein the spaces have widths; shrinking the widths of the spaces between the parts of the filler material with a shrink sidewall deposition where the shrink sidewall deposition provides a deposition over the memory region; etching a second set of sacrificial layer features into the second sacrificial layer through the shrink sidewall deposition, where the second set of sacrificial layer features are only in the memory region and not in the peripheral region; removing the filler material and shrink sidewall deposition; forming a peripheral patterned mask over the memory region and peripheral region, where features are provided over the peripheral region; etching the second sacrificial layer through the peripheral patterned mask, wherein features are etched into the second sacrificial layer in the peripheral region; removing the peripheral patterned mask; and etching features into the etch layer from the second sacrificial layer.