In situ STM imaging of high temperature oxygen etching of Si(111)(7 × 7) surfaces

✍ Scribed by A. Feltz; U. Memmert; R.J. Behm

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 665 KB
• Volume: 192
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85464-l

✦ Synopsis

Gas phase etching of Si( 111) (7 x 7) surfaces, by reaction with O2 at zz 950 K, was directly followed by in situ STM imaging. The reaction mechanism was found to strongly depend on the density of structural defects in the respective (7 X 7) surface layer, which can act as nucleation centers for pit formation, and on the terrace size. Under present conditions we observed a step-flow mechanism for removal of the topmost, defect-free Si layer and formation of monolayer deep pits in the defective (7 x 7) layers in the further reaction process. The resulting surface is rough on an atomic scale, with typically three layers exposed.