Patent ID: 9324722
Filing Date: 2016-04-26
CPC Classification: H01L

Claim Text:
1. A method comprising: forming a hard-mask layer on an upper surface of a silicon oxide layer; forming spaced parallel mandrels on an upper surface of the hard-mask layer; forming spacers on opposite sides of each mandrel and removing the mandrels, forming alternating mandrel and non-mandrel spaces; forming block-mask portions over the mandrel and non-mandrel spaces, over the upper surface of the hard-mask layer; removing exposed sections of the hard-mask layer exposing sections of an upper surface of the silicon oxide layer, and removing the block-mask portions; forming a cut-mask with openings shorter than the block-mask portions over the upper surface of the hard-mask layer in areas where the block-mask portions had been; removing the hard-mask layer through the cut-mask openings, and removing the cut-mask; forming cavities in exposed regions of the silicon oxide layer; removing the spacers and any remaining hard-mask layer; and forming metal lines in the cavities.