Accession Number:

ADA277253

Title:

Lowering the Schottky Barrier at Metal or Silicide/Si Interfaces to Extend the Range of Infrared Detectors

Descriptive Note:

Final rept. Sep 1992-Aug 1993

Corporate Author:

UNIVERSITY OF WALES COLL OF CARDIFF (UNITED KINGDOM) DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s):

Report Date:

1993-11-01

Pagination or Media Count:

26.0

Abstract:

Si and group IV based Schottky barriers SB below about 0.2eV are of considerable technological importance since detectors based upon them will be able to probe deep into the infrared while maintaining well established processing techniques. Investigations relating to this problem have been carried out using ultra-high vacuum techniques and X-ray photoelectron spectroscopy. Two approaches have been pursued, one by tailoring the interface geometric and hence electronic structure and the other by using a reduced band gap material. The systems studied were Sn on Si111 and Pt on Ge111. Sn invokes several surface reconstructions on Si111 one of which, the 2 square root of 3 structure has an associated electronic structure with the Fermi level situated 0.14 - 0.10eV above the valence band maximum VBM. This means that the corresponding p-type SB is also 0.14 - 0.10 eV, well below the value of 0.22eV found at the PtSi Si100 interface. Similarly, when Pt was deposited onto Ge100, the Fermi level was positioned 0.12 - 0.04eV above the VBM, again resulting in a p- type SB significantly lower than that at the PtSiSi100 interface. Chemical interactions at the PtGe interface are discussed.

Subject Categories:

  • Inorganic Chemistry
  • Physical Chemistry
  • Electrical and Electronic Equipment
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE