Patent ID: 9613806
Date: 2017-04-04
CPC Classifications: H01L

Claim:
1. A method of forming a hard mask layer comprising: forming a plurality of mandrels that have a lateral dimension D which is defined by a photolithographic process and which are separated by spaces having a lateral dimension equal to D; subsequently forming sidewall spacers of a first material along and in direct contact with sides of the mandrels, gaps between neighboring sidewall spacers having a lateral dimension approximately equal to D/3; subsequently depositing a first hard mask layer of a second material to completely fill the gaps between the sidewall spacers with the second material; subsequently etching the plurality of mandrels to expose sides of the sidewall spacers; subsequently depositing a second hard mask layer of the second material to partially fill openings where the plurality of mandrels were etched, the second hard mask layer lying along and in direct contact with the sides of the sidewall spacers of the first material exposed by the etching; subsequently etching back the second material of at least the second hard mask layer to leave first hard mask portions completely filling the gaps between sidewall spacers and second hard mask portions that extend along and in direct contact with the sidewall spacers on one side and are exposed on another side; wherein both the first and second hard mask portions have lateral dimensions of approximately D/3 and spacing of approximately D/3; and subsequently removing the sidewall spacers.