Patent ID: 6679976
Filing Date: 2004-01-20
Classification: C23C,H01J

Abstract:
A multi-target system for performing sputter deposition, comprising:(a) at least one ion source that generates at least one ion current directed at least first and second targets; (b) at least one electron source that generates at least one electron current directed at the at least first and second targets; (c) biasing circuitry that biases the first target with a first DC voltage pulse signal and that biases the second target with a second DC voltage pulse signal that is independent of the first DC voltage pulse signal, the biasing circuitry being formed from at least one voltage source with respect to ground, a first high frequency switch used to form the first DC voltage pulse signal, and a second high frequency switch used to form the second DC voltage pulse signal; (d) a first current sensor, coupled to the biasing circuitry, that monitors a positive current and a negative current from the first target during one or more cycles of the first DC voltage pulse signal; (e) a second current sensor, coupled to the biasing circuitry, that monitors a positive current and a negative current from the second target during one or more cycles of the second DC voltage pulse signal; (f) a controller, coupled to the first and second current sensors, that varies the at least one ion current independently from the at least one electron current; (g) wherein the at least one ion source and the at least one electron source create a continuous plasma proximate the first and second targets, and the biasing circuitry causes the first and second targets to alternately attract ions and electrons from the plasma; (h) wherein the ions attracted from the plasma sputter the first and second targets and material from the first and second targets is deposited on a substrate; and (i) wherein the electrons attracted from the plasma neutralize accumulated charge on the first and second targets.