We investigated the initial oxidation of Si(100) with ozone by comparison with oxidation by oxygen molecules using a specially fabricated ozone generator that could supply concentrated (typically 30 at.%) ozone gas at 1 atm pressure. We measured the thickness of the SiO2 film on the Si by XPS, using a thermal oxide film with a known thickness as a reference. We observed the growth of an SiO2 film on Si by ozone even at a sample temperature of 200 °C, verifying the strong oxidation power of ozone. The SiO2 film was approximately 2.3 nm thick for 100 min of exposure. The kinetics of oxidation with ozone showed a power law dependence relative to exposure time, with almost the same power value for the ozone gas at 1 atm as at 2000 Pa. However, the growth of the SiO2 film was saturated at the level of one monolayer when the ozone gas was supplied at 10-4 Pa, which suggests to us a rapid decrease of the sticking (or reaction) probability of ozone on monolayer SiO2.
|ジャーナル||Surface and Interface Analysis|
|出版ステータス||Published - 2000 8 1|
|イベント||8th European Conference on Applications of Surface and Interface Analisys, ECASIA 99 - Sevilla, Spain|
継続期間: 1999 10 4 → 1999 10 8
ASJC Scopus subject areas
- 化学 (全般)