Patent ID: 6812140
Filing Date: 2004-11-02
Classification: H01L

Abstract:
A method for contact profile improvement, wherein the contact is formed on a substrate having at least one element formed thereon, the method comprising:forming an oxide layer on the substrate; forming a borophosphosilicate glass layer on the oxide layer; forming a contact window in the oxide layer and the borophosphosilicate glass layer, wherein the element on the substrate is exposed by the contact window, a silicon material of the element reacts with a gas containing oxygen and native oxide is formed thereon; forming an insulation layer on the borophosphosilicate glass layer, a sidewall and a bottom of the contact window, wherein overhangs are formed at an opening of the contact window; forming a spacer on the sidewall of the contact window by etching the insulation layer; and removing the native oxide by a wet etching process, wherein an etching selection ratio (etching rate of the native oxide)/(etching rate of the spacer) is smaller than 1.