International Business Machines Corporation
Tiered-Profile Contact for Semiconductor

Abstract:

Tiered-profile contacts for semiconductor devices and techniques for formation thereof are provided In one aspect, a method for forming tiered-profile contacts to a semiconductor device includes: depositing a first oxide layer over the semiconductor device; depositing a second oxide layer on the first oxide layer; patterning contact trenches through the first/second oxide layer down to the semiconductor device; isotropically etching a top portion of the contact trenches selective to a bottom portion of the contact trenches based on the second oxide layer having a greater etch rate than the first oxide layer to make the top portion of the contact trenches wider than the bottom portion; and filling the contact trenches with a contact metal(s) to form the tiered-profile contacts. Other methods to form tiered-profile contacts using sacrificial spacers as well as structures including the present tiered-profile contacts are also provided.