Surface oxide layers of Si and Ge nanocrystals

✍ Scribed by S. Hayashi; S. Tanimoto; M. Fujii; K. Yamamoto

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 537 KB
• Volume: 8
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1016/0749-6036(90)90267-b

✦ Synopsis

Surface oxide layers for5ed on gas-evaporated Si and Ge microcrystals as small as 1OOA were investigated by means of infrared spectroscopy, high-resolution electron Ficroscopy and X-ray photoemission spectroscopy. It is shown that 20A-thick native oxide layers in the form of SiO, with x=-1.2 are first formed on the surfaces of Si microcrystals. When the microcrystals are annealed in air at 4OO'C, the composition x increases up to 2, but the oxide thickness remains almost the same. The evolution of the oxide occurs in the first 15min of annealing and saturates afterwards. This implies that stable oxide layers (Si02) can successfully be obtained by annealing at relatively low temperatures. Results obtained for Ge microcrystals are qualitatively the same and indicate that stable oxide coatings can be obtained by annealing at 3OO'C for 30min.