We have investigated the influence of oxygen pressure on the plasma anodization of silicon. The observed variation of the oxide growth rate with oxygen pressure can be accounted for by two effects. Firstly, the increase in the number of oxygen ions increases the growth rate but at higher pressures the interaction between the oxygen species themselves causes fewer oxygen ions to reach the target and hence the rate decreases. Secondly, the target area decreases with increasing gas pressure, leading to a lower growth rate. It was found that the electrical properties of the SiO2 films prepared in this study also depended on the oxygen pressure. The most useful value of the dielectric constant for good anodic SiO2 films with a low density of trapped charge was found to be 3.7.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry