Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Microscopic structure of the SiO/sub 2//Si interface

Journal Article · · Phys. Rev. B: Condens. Matter; (United States)

The bonding of Si atoms at the SiO/sub 2//Si interface is determined via high-resolution core-level spectroscopy with use of synchrotron radiation. All four oxidation states of Si are resolved, and their distribution is measured for Si(100) and Si(111) substrates. For oxides grown in pure O/sub 2/, the density of Si atoms in intermediate oxidation states is (1.5 +- 0.5) x 10/sup 15/ cm/sup -2/. This value is obtained by measuring the core-level intensity, the escape depth in Si and SiO/sub 2/, and the relative Si 2p photoionization cross section for different oxidation states. From the density and distribution of intermediate-oxidation states, models of the interface structure are obtained. The interface is not abrupt, as evidenced by the high density of intermediate-oxidation states (about two monolayers of Si) and by their nonideal distribution. The finite width of the interface is explained by the bond-density mismatch between SiO/sub 2/ and Si. The electrical properties of the interface (band lineup, Fermi, and vacuum level) are determined. Annealing in H/sub 2/ is found to influence the electrical parameters by removing the P/sub b/ centers that pin the Fermi level. The distribution of oxidation states is not affected.

Research Organization:
IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598
OSTI ID:
6780702
Journal Information:
Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:9; ISSN PRBMD
Country of Publication:
United States
Language:
English