Self-aligned contact structure

摘要

Embodiments of present invention provide a method of forming a semiconductor structure. The method includes forming a semiconductor structure having a first metal layer and a plurality of dielectric layers on top of the first metal layer; creating one or more openings through the plurality of dielectric layers to expose the first metal layer underneath the plurality of dielectric layers; causing the one or more openings to expand downward into the first metal layer and expand horizontally into areas underneath the plurality of dielectric layers; applying a layer of lining material in lining sidewalls of the one or more openings inside the plurality of dielectric layers; and filling the expanded one or more openings with a conductive material.

主权项

1. A method comprising:
forming a transistor structure having an aluminum gate and one or more inter-layer-dielectric (ILD) layers on top of said aluminum gate; creating one or more contact holes through said one or more ILD layers to expose said aluminum gate underneath said one or more ILD layers; causing said one or more contact holes to expand into said aluminum gate and horizontally into areas underneath said one or more ILD layers by applying an isotropic etching process to etch said exposed aluminum gate, said isotropic etching process being selective to said one or more ILD layers and leaving said one or more ILD layers substantially unaffected during said isotropic etching process; and filling said expanded contact holes with a conductive material.