Vacancy-assisted halogen etching of Si(100)-2x1

K. NAKAYAMA, C.M. ALDAO, Y J.H. WEAVER

PHYSICAL REVIEW LETTERS

Año: 1999 vol. 82 p. 568 - 571

0031-9007

Scanning tunneling microscopy studies of etching of Si(100)-2x1 show that the rate of terrace pit formation goes through a maximum for surface coverages of q(Cl)=0.77±0.05 monolayer, in contrast to predictions of conventional models. Using recently calculated energies for different possible surface configurations, we show that a key component in desorption is the formation of a single-atom vacancy adjacent to a volatile SiCl2 unit. The demonstration of vacancy-assisted reaction establishes a self-limited reaction and the sequence of events leading to desorption.