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Title: EL2 distributions in vertical gradient freeze GaAs crystals

Abstract

Spatial distributions of EL2 in undoped, semi-insulating GaAs crystals grown by a novel vertical gradient freeze (VGF) method are reported. As a result of the low-temperature gradients present during growth and post-solidification cooling, these crystals exhibit lower EL2 concentrations and lower dislocation densities than liquid-encapsulated Czochralski crystals. Both the EL2 distribution and dislocation density over the area of a wafer do not display the fourfold symmetric pattern prevalent for LEC-grown GaAs. The radial distributions of EL2 in as-grown VGF crystals have been found to be independent of the dislocation density. Axial and radial Hall-effect measurements are included. Thermal activation energies are also presented and the compensation mechanism for this material is discussed.

Authors:
; ; ; ;
Publication Date:
Research Org.:
ATandT Bell Laboratories, 2525 North 12 Street, Reading, Pennsylvania 19612-3566
OSTI Identifier:
5254549
Resource Type:
Journal Article
Journal Name:
J. Appl. Phys.; (United States)
Additional Journal Information:
Journal Volume: 63:12
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; GALLIUM ARSENIDES; CRYSTAL DEFECTS; PHYSICAL RADIATION EFFECTS; CATHODOLUMINESCENCE; CRYSTAL GROWTH METHODS; EXPERIMENTAL DATA; NEAR INFRARED RADIATION; POINT DEFECTS; ARSENIC COMPOUNDS; ARSENIDES; CRYSTAL STRUCTURE; DATA; ELECTROMAGNETIC RADIATION; GALLIUM COMPOUNDS; INFORMATION; INFRARED RADIATION; LUMINESCENCE; NUMERICAL DATA; PNICTIDES; RADIATION EFFECTS; RADIATIONS; 360602* - Other Materials- Structure & Phase Studies

Citation Formats

Gray, M L, Sargent, L, Blakemore, J S, Parsey, Jr, J M, and Clemans, J E. EL2 distributions in vertical gradient freeze GaAs crystals. United States: N. p., 1988. Web. doi:10.1063/1.340304.
Gray, M L, Sargent, L, Blakemore, J S, Parsey, Jr, J M, & Clemans, J E. EL2 distributions in vertical gradient freeze GaAs crystals. United States. https://doi.org/10.1063/1.340304
Gray, M L, Sargent, L, Blakemore, J S, Parsey, Jr, J M, and Clemans, J E. Wed . "EL2 distributions in vertical gradient freeze GaAs crystals". United States. https://doi.org/10.1063/1.340304.
@article{osti_5254549,
title = {EL2 distributions in vertical gradient freeze GaAs crystals},
author = {Gray, M L and Sargent, L and Blakemore, J S and Parsey, Jr, J M and Clemans, J E},
abstractNote = {Spatial distributions of EL2 in undoped, semi-insulating GaAs crystals grown by a novel vertical gradient freeze (VGF) method are reported. As a result of the low-temperature gradients present during growth and post-solidification cooling, these crystals exhibit lower EL2 concentrations and lower dislocation densities than liquid-encapsulated Czochralski crystals. Both the EL2 distribution and dislocation density over the area of a wafer do not display the fourfold symmetric pattern prevalent for LEC-grown GaAs. The radial distributions of EL2 in as-grown VGF crystals have been found to be independent of the dislocation density. Axial and radial Hall-effect measurements are included. Thermal activation energies are also presented and the compensation mechanism for this material is discussed.},
doi = {10.1063/1.340304},
url = {https://www.osti.gov/biblio/5254549}, journal = {J. Appl. Phys.; (United States)},
number = ,
volume = 63:12,
place = {United States},
year = {1988},
month = {6}
}