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Atom-resolved surface chemistry: The early steps of Si(111)-7 times 7 oxidation

Journal Article · · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States)
DOI:https://doi.org/10.1116/1.585584· OSTI ID:5228070
; ;  [1]
  1. T. J. Watson Research Center, Yorktown Heights, NY (United States)

In this report the early stages of Si(111)-7{times}7 oxidation using scanning tunneling microscopy and scanning tunneling and photoemission spectroscopies have been studied. It has been found that there are at least two different oxygen-containing sites being formed. Their different surface site distributions and behavior as a function of O{sub 2}-exposure show them to be two distinct early products. By correlating the spectroscopic results and the results of theoretical calculations one is able to identify one of these products as involving an O atom tying up an adatom dangling bond with a second O atom inserted in one of the adatom back bonds, while the other involves a single O atom inserted in an adatom back bond. The preference of these products for the faulted half of the 7{times}7 unit cell and for corner-adatom sites is explained in terms of a site-dependent sticking coefficient involving a process analogous to the gas-phase harpooning processes. It is shown that the majority of the resulting molecular precursors involve O{sub 2} interacting with a single dangling-bond site. Finally, mechanisms are proposed for the early steps of the oxidation process.

OSTI ID:
5228070
Journal Information:
Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States), Journal Name: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States) Vol. 9:2; ISSN 0734-211X; ISSN JVTBD
Country of Publication:
United States
Language:
English