Investigation Of Plasma Property Of Dual-frequency Magnetron Sputtering Driven By Radio-frequency And Very-high-frequency Sources

In order to control the growth and the structure of multi-components thin films prepared by magnetron sputtering, the dual-magnetron sputtering driven simultaneously by radio-frequency(RF) and very-high-frequency(VHF) sources is a possible method.However, the RF and VHF dual-frequency discharge is mainly applied in the plasmaenhanced chemical vapor deposition(PECVD). The magnetron sputtering driven simultaneously by RF and VHF dual-frequency is seldom reported. In this work, the effect of driving frequency and power on plasma property of RF and VHF dual-frequency magnetron sputtering is investigated.This thesis studies the ions energy distributions(IEDs) of dual-frequency magnetron sputtering driven by 2MHz/13.56(27.12 or 60) MHz, 13.56MHz/27.12(60) MHz and27.12MHz/60 MHz using retarding field energy analyzer, as well as the electrons energy distributions(EEDs), the electron density, electron temperature and plasma potential of dual-frequency magnetron sputtering driven by 13.56MHz/ 27.12(60)MHz and27.12MHz/60 MHz using Langmuir probe. It is found that increasing power ratio of 2 MHz to 13.56(27.12 or 60) MHz led to the evolution of IEDs from a uni-modal distribution towards a uni-modal distribution with high-energy peak shoulder and a bi-modal distribution. While increasing power ratio of 13.56 MHz to 27.12 MHz and 27.12 MHz to60 MHz led to the increase of peak energy. The evolution of IEDs shape and the increase of peak energy are due to the change of ions responding to the average field of highfrequency period towards the instantaneous sheath potential of low-frequency period. It is also found that the EEDs, the electron density, electron temperature and plasma potential depend on the two frequencies used in the sputtering. The investigation on plasma propertyof ICP-assisted dual-frequency magnetron sputtering shows that the increase of plasma density also depends on the two frequencies used in the sputtering. By choosing two frequencies properly, the plasma density can be increased effectively while the ions energy distributions have small change. Therefore, the dual-frequency magnetron sputtering driven simultaneously by RF and VHF sources is a possible way to deposit the multicomponents thin films.