Stoichiometry-related defects in GaAs grown by molecular-beam epitaxy at low temperatures

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · J. Vac. Sci. Technol., B; (United States)

DOI:https://doi.org/10.1116/1.584630· OSTI ID:5952014

Kaminska, M; Weber, E R; Liliental-Weber, Z; Leon, R; Rek, Z U

GaAs layers grown by molecular-beam epitaxy (MBE) at very low substrate temperatures have gained considerable interest as buffer layers for GaAs metal--semiconductor field effect transistors (MESFET's) due to high resistivity and excellent device isolation. However, the structure and the electronic properties of such layers have not yet been investigated in detail. We have studied unannealed low temperature (LT) MBE layers grown at 200 /degree/C using transmission electron microscopy (TEM), analytical TEM, x-ray diffraction, the Hall effect, and electron paramagnetic resonance (EPR) techniques. TEM data indicated large arsenic-rich deviations from stoichiometry of /similar to/1--1.5 at. %. X-ray rocking curves showed a uniform increase of 0.1% in all directions of lattice parameters compared to semi-insulating GaAs substrate. The Hall effect and thermally induced changes of photo-EPR measurements revealed the presence of an acceptor level at an energy of /similar to/0.3 eV above the valence band. This acceptor level has been tentatively attributed to a gallium vacancy defect.

• Research Organization: Department of Materials Science and Mineral Engineering and Center for Advanced Materials, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720(US); Stanford Synchrotron Radiation Laboratory, Stanford, California 94309
• OSTI ID: 5952014
• Journal Information: J. Vac. Sci. Technol., B; (United States), Journal Name: J. Vac. Sci. Technol., B; (United States) Vol. 7:4; ISSN JVTBD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ARSENIC COMPOUNDS
ARSENIDES
COHERENT SCATTERING
CRYSTAL GROWTH
DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPIN RESONANCE
EPITAXY
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HALL EFFECT
HIGH TEMPERATURE
LAYERS
MAGNETIC RESONANCE
MICROSCOPY
MOLECULAR BEAM EPITAXY
PNICTIDES
RESONANCE
SCATTERING
STOICHIOMETRY
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION