Filling narrow openings using ion beam etch

Abstract

Generally, the subject matter disclosed herein relates to modern sophisticated semiconductor devices and methods for forming the same, wherein a multilayer metal fill may be used to fill narrow openings formed in an interlayer dielectric layer. One illustrative method disclosed herein includes forming an opening in a dielectric material layer of a semiconductor device formed above a semiconductor substrate, the opening having sidewalls and a bottom surface. The method also includes forming a first layer of first fill material above the semiconductor device by forming the first layer inside the opening and at least above the sidewalls and the bottom surface of the opening. Furthermore, the method includes performing a first angled etching process to at least partially remove the first layer of first fill material from above the semiconductor device by at least partially removing a first portion of the first layer proximate an inlet of the opening without removing a second portion of the first layer proximate the bottom of said opening, and forming a second layer of second fill material above the semiconductor device by forming the second layer inside the opening and above the first layer.