H-2 molecules in crystalline silicon

Citation
Re. Pritchard et al., H-2 molecules in crystalline silicon, MAT SCI E B, 58(1-2), 1999, pp. 1-5
Citations number
16
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY
ISSN journal
09215107 → ACNP
Volume
58
Issue
1-2
Year of publication
1999
Pages
1 - 5
Database
ISI
SICI code
0921-5107(19990212)58:1-2<1:HMICS>2.0.ZU;2-V
Abstract
Infrared spectra from low-doped, hydrogenated silicon have revealed very we ak absorption from hydrogen molecules. In Czochralski silicon, vibrational modes from molecules paired with interstitial oxygen atoms (O-i-H-2) have b een identified, together with a vibrational mode (v(3HH)) from molecules tr apped at a second site. A low temperature annealing study (T < 200 degrees C) has now led to the proposal that this second site is an interstitial lat tice site with the axes of the isolated molecules aligned along either [111 ] or [110] to account for their IR activity. The v(3HH) mode is also detect ed in hydrogenated, boron-doped float zone (FZ) Si, together with the stret ch mode of H-B pairs. An estimate of the molecular concentration indicates that this is the source of so-called 'hidden hydrogen' that is observed for boron-doped Si. This identification is confirmed in the present sample by a second low temperature annealing study. Further work is in progress to es tablish the dissociation mechanism of H-2 molecules and the subsequent form ation of H-B pairs. (C) 1999 Elsevier Science S.A. All rights reserved.