The surface morphological change at an initial stage of thermal oxidation on Si(0 0 1) surface with O 2 was investigated as a function of oxide coverage by a real-time monitoring method of Auger electron spectroscopy (AES) combined with reflection high energy electron diffraction (RHEED). At 653 °C where oxide islands grow laterally, protrusions were observed to develop under the oxide islands as a consequence of concurrent etching of the surface. The rate of etching was measured from a periodic oscillation of RHEED half-order spot intensity I (1/2,0) and I (0,1/2) . At 549 °C where Langmuir-type adsorption proceeds, it was observed that both I (1/2,0) and I (0,1/2) decrease more rapidly in comparison with an increase of oxide coverage and the intensity ratio between them decreases gradually with O 2 exposure time. These suggest that Langmuir-type adsorption occurs at sites where O 2 adsorbs randomly, leading to subdivision of the 2 × 1 and 1 × 2 domains by oxidized regions, and that Si atoms are ejected due to volume expansion in oxidation to change the ratio between 2 × 1 and 1 × 2 domains.
|ジャーナル||Applied Surface Science|
|出版ステータス||Published - 2002 5 8|
|イベント||Proceedings of the 8th International COnference on the form (ICFSI-8) - , Japan|
継続期間: 2001 6 10 → 2001 6 10
ASJC Scopus subject areas
- 化学 (全般)