Pulse bias sputtering of copper onto insulating surfaces

The effects of charge accumulation during bias sputtering of copper onto an insulating material are studied. To eliminate the effects of charge accumulation, we periodically apply a pulse bias to the electrode. Microstructure and electrical properties of the sputtered copper films grown on silicon dioxide are measured as a function of the pulse bias frequency. By comparing the observed properties of these films grown under a pulse bias to those grown under a dc bias (with a conducting path to the electrode), the effectiveness of the pulse bias in controlling the ion energy distribution is demonstrated.