Patent ID: 9679850
Date: 2017-06-13
CPC Classifications: H01L

Claim:
1. A method of fabricating a semiconductor structure, comprising: forming an etching stop layer over an inter-layer dielectric (ILD) layer; forming a dielectric layer over the etching stop layer; forming a nitrogen free anti-reflection layer (NFARL) over the dielectric layer; forming a metal-hard-mask (MHM) layer over the NFARL; forming a tapered aperture at least going through the MHM layer, the NFARL and into the dielectric layer; and filling the tapered aperture with copper; wherein the tapered aperture tapers inwardly from a mouth surface portion to a bottom surface portion, wherein a width of the mouth surface portion is greater than a width of the bottom surface portion, and the width of the bottom surface portion is less than about 50 nm.