Fabrication of ultrathin silicon dioxide layers in room temperature by ultrahigh vacuum plasma oxidation

Plasma oxidation of silicon in room temperature and in an ultrahigh vacuum has been found to be a useful tool in producing very thin silicon dioxide layers. The maximum thickness that can be reached, however, is only 1–1.1 nm. As the needed layer thickness is usually from 2 to 5 nm, the process has to be performed in several oxidation cycles. Using this method, a good thickness control can be achieved and the resulting MOS structures have relatively low surface state densities and a high breakdown field.