High-Power Pulsed Magnetron Sputtering

Abstract

Magnetically enhanced sputtering methods and apparatus are described. A magnetically enhanced sputtering source according to the present invention includes an anode and a cathode assembly having a target that is positioned adjacent to the anode. An ionization source generates a weakly-ionized plasma proximate to the anode and the cathode assembly. A magnet is positioned to generate a magnetic field proximate to the weakly-ionized plasma. The magnetic field substantially traps electrons in the weakly-ionized plasma proximate to the sputtering target. A power supply produces an electric field in a gap between the anode and the cathode assembly. The electric field generates excited atoms in the weakly ionized plasma and generates secondary electrons from the sputtering target. The secondary electrons ionize the excited atoms, thereby creating a strongly-ionized plasma having ions that impact a surface of the sputtering target to generate sputtering flux.

Description

BACKGROUND OF THE INVENTION [0001] Sputtering is a well-known technique for depositing films on substrates. Sputtering is the physical ejection of atoms from a target surface and is sometimes referred to as physical vapor deposition (PVD). Ions, such as argon ions, are generated and then directed to a target surface where the ions physically sputter target material atoms. The target material atoms ballistically flow to a substrate where they deposit as a film of target material. [0002] Diode sputtering systems include a target and an anode. Sputtering is achieved in a diode sputtering system by establishing an electrical discharge in a gas between two parallel-plate electrodes inside a chamber. A potential of several kilovolts is typically applied between planar electrodes in an inert gas atmosphere (e.g., argon) at pressures that are between about 10−1 and 10−2 Torr. A plasma discharge is then formed. The plasma discharge is separated from each electrode by what is referred to as t...

AI Technical Summary

Problems solved by technology

Conventional magnetron sputtering systems deposit films that have relatively low uniformity.

However, the film uniformity can be increased by mechanically moving the substrate and / or the magnetron, but such systems are relatively complex and expensive to implement.

Conventional magnetron sputtering systems also have relatively poor target utilization.

By poor target utilization, we mean that the target material erodes in a non-uniform manner.

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