Top corner rounding by implant-enhanced wet etching

摘要

When forming metallization layers of advanced semiconductor devices, one often has to fill apertures with a high aspect ratio with a metal, such as copper. The present disclosure provides a convenient method for forming apertures with a high aspect ratio in an insulating layer. This insulating layer may have been deposited on the surface of a semiconductor device. The proposed method relies on an ion implantation step performed on the insulating layer, followed by an etch, which is preferably a wet etch.

主权项

1. A method, comprising:
forming a transistor structure comprising a gate electrode, a source region and a drain region in and above a semiconductor layer; forming an insulating layer above the surface of said semiconductor layer after forming said transistor structure; performing a first etch process in order to form at least one opening in a predetermined portion of said insulating layer; performing an ion implantation so as to implant impurity ions into an upper portion of said insulating layer; and performing a second etch process so as to remove at least a portion of said insulating layer comprising the implanted impurity ions after performing said ion implantation; wherein during said second etch process said upper portion of said insulating layer comprising the implanted impurity ions is etched at a different rate from the remaining portion of said insulating layer.