Dresden 2006 – scientific programme
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HL: Halbleiterphysik
HL 23: Interfaces/surfaces
HL 23.7: Talk
Tuesday, March 28, 2006, 18:45–19:00, BEY 154
Removal of carbon and oxygen contaminants from silicon surfaces by atomic hydrogen — •Tanja Stimpel-Lindner1, Markus Schindler1, Günther Dollinger2, Hermann Baumgärtner1, and Ignaz Eisele1 — 1Institut für Physik, Fakultät für Elektrotechnik, Universität der Bundeswehr München, 85577 München-Neubiberg, Deutschland — 2Institut für Angewandte Physik und Messtechnik, Fakultät für Luft- und Raumfahrttechnik, Universität der Bundeswehr München, 85577 München-Neubiberg, Deutschland
For the growth of nanostructures on silicon (Si), the previous cleaning of the substrate surface is an important step. Common processes for surface preparation in UHV involve temperatures up to 1200∘C. For atomically sharp doping profiles and other innovative structures, this is far too high. Cleaning procedures at lower temperature regularly either leave carbon (C) and oxygen on the surface or produce a significant roughening of the surface which is also unwanted. In our work, a cleaning process using atomic hydrogen was developed. Starting from oxide-covered Si(100) after RCA-Cleaning or native silicon dioxide, both covered with carbon contaminations, the surfaces were exposed to atomic hydrogen which was generated by dissociative adsorption of hydrogen on a hot tantalum surface. With this new process, C can already be removed at substrate temperatures of about 500∘C. Oxygen removal starts at slightly higher temperatures. The cleaning process was investigated in detail by XPS, AES and STM. These results will be compared with cleaning processes used by the semiconductor industry which also employ hydrogen.