SiおよびSi化合物表面からのSiクラスターの熱脱離 (II)
Siクラスターと弱く相互作用するSi安定化グラファイト表面とSiC表面
2000 年 43 巻 10 号 p. 978-985
詳細
2000 年 43 巻 10 号 p. 978-985
We studied thermal desorption of Si clusters from graphite and SiC surfaces using quadrupole mass spectrometry and scanning tunneling microscopy (STM) in search of a substrate whose surface is inert to Si clusters. Although graphite was found to react with Si clusters, an inert surface was formed when Si vapor was sufficiently supplied to the graphite surface at 1500°C. This Si-stabilized graphite surface, from which Si clusters desorbed even at 400°C was considered to be composed of polycrystalline SiC. This observation led us to study interaction of Si clusters with single crystalline 6H-SiC (0001) surfaces. Thermal desorption spectroscopy showed that three types surfaces appeared when Si-deposited SiC was annealed. The most inactive one formed at>1500°C and the structure was identified as 6 √3× 6√3R30° by STM. The activation energy for desorption of Si, Si2, and Si3 from the surface was measured to be 46, 49, and 66 meV. These small values evidenced the physisorption of Si atoms and clusters on the surface.
