Ion property and electrical characteristics of 60 MHz very-high-frequency magnetron discharge at low pressure

The pre-ionized 60 MHz very-high-frequency (VHF) magnetron discharge at low pressure, assisted by inductively coupled plasma (ICP) discharge, was developed. The measurement of ion flux density and ion energy to the substrate was carried out by a retarding field energy analyzer. The electric characteristics of discharge were also investigated by voltage-current probe technique. It was found that by reducing the discharge pressure of VHF magnetron discharge from 5 to 1 Pa, the ion flux density increased about four times, meanwhile the ion energy also increased doubly. The electric characteristics of discharge also showed that a little improvement of sputtering effectiveness was achieved by reducing discharge pressure. Therefore, the deposition property of VHF (60 MHz) magnetron sputtering can be improved by reducing the discharge pressure using the ICP-assisted pre-ionized discharge.