Microstructures of (In,Ga)P alloys grown on GaAs by metalorganic vapor-phase epitaxy

Journal Article · Sat Apr 01 04:00:00 EST 1995 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.358659· OSTI ID:6565894

Follstaedt, D M; Schneider, Jr, R P; Jones, E D ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1056 (United States)

The microstructures of metalorganic vapor-phase epitaxy alloys of (In,Ga)P grown on GaAs substrates were examined using transmission electron microscopy. Alloys examined were grown at 600--775 [degree]C on substrates at or near (001) or (113)[sub A] using growth rates of 0.69 and 0.17 nm/s. Two common semiconductor alloy phenomenon, ordering and phase separation, were studied over this range of growth conditions. The CuPt-type ordering reflections are sharpest for growth at 675 [degree]C and more diffuse at 600 and 725 [degree]C due to higher densities of antiphase boundaries. Order can be eliminated by growth at 750 [degree]C or above to obtain the highest band gaps and optical emission energies. Detailed investigation of the microstructure for growth at 675 [degree]C indicates that ordered domains are platelets consisting of thin (1--2 nm) lamella on (001) planes that alternate between the two [l brace]111[r brace][sub B] ordering variants, in agreement with a model proposed by others. We have formed unicompositional'' quantum wells with sharply defined ordered layers between disordered barrier layers by changing growth temperature, which demonstrates that ordering is determined to a great degree by the conditions during growth. Phase separation is seen for the entire range of growth parameters, independently of ordering; its contrast shows modulations with a variable spacing ranging from a few nanometers to [similar to]100 nm. Implications of the coexistence of phase separation and ordering for growth models describing these phenomena are discussed.

• DOE Contract Number: AC04-94AL85000
• OSTI ID: 6565894
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 77:7; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ELECTRON MICROSCOPY
EPITAXY
GALLIUM COMPOUNDS
GALLIUM PHOSPHIDES
GRAIN BOUNDARIES
INDIUM COMPOUNDS
INDIUM PHOSPHIDES
MICROSCOPY
MICROSTRUCTURE
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PNICTIDES
TEMPERATURE DEPENDENCE
TRANSMISSION ELECTRON MICROSCOPY
VAPOR PHASE EPITAXY