Accession Number:

ADA357736

Title:

Molecular Beam Epitaxy of Sb-based Semiconductors

Descriptive Note:

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

Report Date:

1998-01-01

Pagination or Media Count:

53.0

Abstract:

The growth of semiconductor antimonides by molecular beam epitaxy MBE was first reported in the late 1970s. In recent years, the emergence of several potential device applications has resulted in increased activity in the field. Much of the work focuses on GaSb and AlSb because they are nearly lattice-matched to each other and to InAs a sub o,AlSb6.1355 A, a sub o,GaSb6.0954 A, a sub ,InAs6.0584 A. These semiconductors are often referred to as the 6.1 A family. Ternaries such as InxGa1-xSb, AlAsxSb1-x, and GaAsxSb1-x also have lattice constants close to 6.1 A if x is small. The interest in 6.1 A materials is based upon the wide range of available band alignments and band gaps. These are illustrated in Fig. 10.1. For example, InAs is a small band gap semiconductor Eg,300K0.36 eV with a small electron effective mass m sub e0.023m sub o and large room-temperature mobility 30,000 sq cmV-s. Hence, it is a candidate for the channel material in high-speed field-effect transistors FETs. AlSb is an indirect-gap semiconductor with a large band gap 1.63 eV. The conduction band offset between AlSb and InAs is 1.35 eV, making AlSb a potential barrier material for FETs. A second example is InAsGaSb. The band alignment is type-II, with the GaSb valence band lying above the InAs conduction band. Short-period superlattices formed with InAs and GaSb have small, tunable energy gaps and high absorption coefficients. Hence, they are candidates for long-wavelength infrared detectors.

Subject Categories:

  • Inorganic Chemistry
  • Electrooptical and Optoelectronic Devices
  • Crystallography
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE