The formation of ordered, ultrathin SiO2/Si(100) interfaces grown on (1 x 1) Si(100)

Citation
N. Herbots et al., The formation of ordered, ultrathin SiO2/Si(100) interfaces grown on (1 x 1) Si(100), MAT SCI E B, 87(3), 2001, pp. 303-316
Citations number
54
Language
INGLESE
art.tipo
Article
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
0921-5107 → ACNP
Volume
87
Issue
3
Year of publication
2001
Pages
303 - 316
Database
ISI
SICI code
0921-5107(200112)87:3<303:TFOOUS>2.0.ZU;2-7
Abstract
Ordering is observed at SiO2/Si(100) interfaces when 2-40 nm thick SiO2 fil ms are grown on passivated, ordered (1 x 1) Si(100) surfaces produced by a novel wet chemical cleaning, A mechanism is proposed for the occurrence of this ordering. The thin oxides are grown by a variety of conventional oxida tion techniques or by rapid thermal oxidation between 750 and 1100 degreesC . The evolution of oxygen, carbon, hydrogen and silicon coverages are detec ted by ion beam analysis (IBA) using a combination of ion channeling, nucle ar resonance, elastic recoil detection and time-of-flight secondary ion mas s spectrometry. IBA detects Si surface peak areal densities lower than that of a disorder-free, bulk-terminated (1 x 1) Si(100) crystal calculated by Monte-Carlo methods. This result indicates that Si substrate atoms are shad owed by Si atoms located in a 2 mn ordered region on the oxide side of the interface. Beyond 2 nm, the oxide becomes amorphous. Reflection high-energy electron diffraction (RHEED) at 10 keV confirms the presence of order: a ( 1 x 1) streaky pattern commensurate with Si(100) is observed instead of an amorphous surface. Infrared (IR) spectroscopy shows that the ordered SiO2/S i(100) interfaces exhibit a constant, well-defined frequency of optical abs orption across a 1 nm thickness in the interfacial oxide region near Si. Th is is in contrast to a rapidly changing frequency found for conventional ox ides in the same region. Thus, IR supports the presence of a well-defined b ond-length and stoichiometry as detected by IBA and RHEED. (C) 2001 Publish ed by Elsevier Science B.V.