Acoustic-jet plating of gold and copper at 7.5 MHz

Abstract

We describe a new type of jet plating that uses a focused high-frequency sound field directed through the center of the jet. The acoustic jet results in an improved morphology for gold and copper depositions although plating rates are not enhanced. Four-point probe measurements of acoustic-jet plated copper lines show up to a 50% decrease in electrical resistivity compared to jet plated deposits.