Alternating hardmasks for tight-pitch line formation

Abstract

A method for forming fins includes forming a three-color hardmask fin pattern on a fin base layer. The three-color hardmask fin pattern has hardmask fins of three mutually selectively etchable compositions. A region on the three-color hardmask fin pattern is masked, leaving one or more fins of a first color exposed. All exposed fins of the first color are etched away with a selective etch that does not remove fins of a second color or a third color. The mask and all fins of a second color are etched away. Fins are etched into the fin base layer by anisotropically etching around remaining fins of the first color and fins of the third color.

Dependencies are inferred from the claim text.