Patent ID: 6191035
Filing Date: 2001-02-20
Classification: H01L

Abstract:
A method of chemical vapor deposition, vapor purging and pressure equalization in a vacuum chamber for depositing a layer of a refractory material on the frontside of a wafer made of semiconductor material without depositing residual refractory materials onto the wafer backside which comprises:providing a flow of an inert gas to the backside of the wafer while maintaining a first wafer backside pressure;depositing the refractory material on the frontside of the wafer while maintaining a first chamber pressure, the first chamber pressure being higher than the first wafer backside pressure;purging the chamber while maintaining a second wafer backside pressure and a second chamber pressure, the second chamber pressure being lower than the first chamber pressure; andequalizing the pressure differential between the frontside and the backside of the wafer while maintaining a third chamber pressure.