Patent ID: 9691658
Date: 2017-06-27
CPC Classifications: H01L

Claim:
1. A method of forming an electrical contact in an integrated circuit, the integrated circuit comprising a substrate, an insulating layer on the substrate, and a metal layer on the insulating layer, wherein the substrate has an active area, an opening is formed through the insulating layer to expose the active area of the substrate, said opening having a bottom end adjacent said active area and a top end spaced from said active area by a thickness of said insulating layer, and the metal layer forms a cusp at the top end of said opening causing a narrowing of said opening at said top end, the method comprising: depositing an initial conductive layer in the opening of the insulating layer to form a liner against a sidewall surface of the insulating layer and against said active area; applying a filler material inside said opening to protect a portion of said liner that is below a level of the cusp; removing the cusp to widen said opening while said filler material protecting said portion of said liner covered thereby; removing said filler material from said opening to expose said portion of said liner; re-lining said opening in the insulating layer with a further conductive layer; and filling the opening in the insulating layer with a conductive material to form an electrically conductive contact extending through the insulating layer.