METHOD OF FABRICATING A TUNGSTEN PLUG IN A SEMICONDUCTOR DEVICE

摘要

In an semiconductor process, a seamless tungsten plug is formed in an inter-layer dielectric by forming the inter-layer dielectric from multiple oxide layers having different wet etch rates, from lowest wet-etch rate for the lowest layer to highest wet-etch rate for the highest layer, forming a hole or trench in the inter-layer dielectric using a dry etch process, reconfiguring the hole or trench to have sloped side walls by performing a wet etch step, and filling the hole or trench with tungsten and etching back the tungsten to form a seamless tungsten plug.

主权项

1. A method of fabricating a tungsten plug in an inter-layer dielectric of a semiconductor device comprising,
forming the inter-layer dielectric from multiple layers of dielectric material having increasing wet etch rates from the lowest to the highest dielectric material layer, etching a hole through the inter-layer dielectric, and performing a wet etch step to change the configuration of the hole to one that has substantially sloped or tapered side walls.