Abstract
Room temperature scanning tunneling microscopy images of Si(001)-(2 × 1) surfaces exposed to at pressures torr and temperatures °C show dramatic surface roughening via formation of long step "fingers" and multilevel Si islands. This is caused by nucleation of oxide clusters, which pin step edges during oxidation-induced surface etching. The nucleation rate (estimated by counting pinning sites) was found to scale as , with . This is consistent with a simple model in which two diffusing surface oxygen species are required to nucleate a stable oxide cluster.
- Received 26 April 1994
DOI:https://doi.org/10.1103/PhysRevLett.73.999
©1994 American Physical Society