Patent ID: 7211179
Filing Date: 2007-05-01
Classification: C23C,H01J

Abstract:
1. Apparatus for sputter deposition of a cathode material comprising: a) a plasma chamber in which a plasma is created containing ions and electrons; b) at least two sputtering anodes disposed in the plasma chamber; c) a target cathode disposed in the plasma chamber in close proximity to the plasma wherein the target cathode is comprised of atoms that can be sputtered therefrom in response to bombardment by ions from the plasma to comprise a film on the surface of a substrate contained in the plasma chamber; and d) an ac power supply connected in parallel with a center tapped inductor having one terminal connected to a first sputtering anode and a first line of the ac power supply, a second terminal connected to a second sputtering anode and a second line of the ac power supply and the center tap of the inductor connected to the target cathode to maintain the target cathode at a negative potential with respect to said plasma wherein the ac power supply drives each anode alternately to an ion collecting state to attract ions in the half cycle that a sputtering anode is at a negative potential relative to the plasma, and an electron collecting state to attract electrons in the half cycle that a sputtering anode is at a small potential relative to the plasma or is near the plasma potential.