Low-energy O+ ion beam induced chemical vapor deposition using hexamethyldisilane or hexamethyldisilazane for silicon dioxide film formation

A methodology for silicon dioxide (SiO2) film formation by an ion beam induced chemical vapor deposition (IBICVD) method using hexamethyldisilane (HMDS) or hexamethyldisilazane (HMDSN) is presented in this paper. In this method, an O+ ion beam was injected onto a substrate in conjunction with the source material (HMDS or HMDSN). The substrate temperature was set at room temperature. The O+ ion energy was 100 eV. After the experiment, a film was found to be deposited on the substrate and the film thickness was about 50 nm in both HMDS and HMDSN cases. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy of the deposited films showed that SiO2 films were formed on the substrates. XPS data of the film which was prepared by the injection of both O+ ions and HMDS to the substrate showed that no obvious peak was observed in the C1s region. On the contrary, a small amount of carbon was included in the film when the film was prepared by the injection of O+ ions in conjunction with HMDSN. These results suggest that HMDS is more suitable than HMDSN as the source material for SiO2 film formation when using the IBICVD method.