Annealing studies of low-temperature-grown GaAs:Be

Journal Article · Sat Feb 15 04:00:00 EST 1992 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.351200· OSTI ID:5080546

Bliss, D E ^[1]; Walukiewicz, W; Ager, III, J W ^[2]; Haller, E E ^[1]; Chan, K T ^[3]; Tanigawa, S ^[4]

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1. Center for Advanced Materials, Materials Science Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States) Department of Materials Science and Mineral Engineering, University of California at Berkeley, Berkeley, California 94720 (United States)
2. Center for Advanced Materials, Materials Science Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
3. Hewlett-Packard Co., Microwave Technology Division, Santa Rosa, California 95403 (United States)
4. Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305 (J

The isochronal and isothermal annealing characteristics of acceptor-doped GaAs:Be grown at low substrate temperatures (300 {degree}C) by molecular-beam epitaxy (LTMBE) have been studied. The Be was introduced in a range of concentrations from 10{sup 16} to 10{sup 19} cm{sup {minus}3}. Electrical measurements of as-grown material up to the highest Be concentration of 10{sup 19} cm{sup {minus}3} show that no free holes are contributed to the valence band even though Raman spectroscopy of the Be local vibrational mode indicates that the majority of the Be impurities occupy substitutional sites. It is proposed that Be acceptors are rendered inactive by the high concentration of As{sub Ga}-related native donor defects present in LTMBE material. The concentration of As{sub Ga}-related defects in the neutral charge state was estimated from infrared absorption measurements to be as high as 3{times}10{sup 19} cm{sup {minus}3}. A distinct annealing stage at 500 {degree}C, similar to that found in irradiation-damaged and plastically deformed GaAs, marks a rapid decrease in the concentration of As{sub Ga}-related defects. A second annealing stage near 800 {degree}C corresponds to the activation of Be acceptors. The presence of gallium vacancies {ital V}{sub Ga} was investigated by slow positron annihilation. Results indicate an excess concentration of {ital V}{sub Ga} in LTMBE layers over bulk-grown crystals. Analysis of isothermal annealing kinetics for the removal of As{sub Ga}-related defects gives an activation energy of 1.7{plus minus}0.3 eV. The defect removal mechanism is modeled with {ital V}{sub Ga}-assisted diffusion of As{sub Ga} to As precipitates.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5080546
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 71:4; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ANNEALING
ARSENIC COMPOUNDS
ARSENIDES
BERYLLIUM ADDITIONS
BERYLLIUM ALLOYS
CRYSTAL DEFECTS
CRYSTAL DOPING
CRYSTAL STRUCTURE
DIFFUSION
EPITAXY
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HEAT TREATMENTS
MOLECULAR BEAM EPITAXY
PNICTIDES
RAMAN SPECTRA
SPECTRA