Use of surface grooves to control ordering in GaAsP

Journal Article · Mon Dec 16 04:00:00 EST 1991 · Applied Physics Letters; (United States)

DOI:https://doi.org/10.1063/1.105750· OSTI ID:5993942

Chen, G S; Stringfellow, G B ^[1]

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1. Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah (USA)

GaAs{sub 1{minus}{ital x}}{ital P}{sub {ital x}} with 0.4{le}{ital x}{le}0.85 forms the CuPt ordered structure during organometallic vapor phase epitaxy (OMVPE). Only the ({bar 1}11) and (1{bar 1}1) variants are observed for growth on (001)-oriented substrates. The mechanism by which ordering occurs is only now being discovered. Total energy calculations, including the effects of surface reconstruction, indicate that the phenomenon can be explained purely on the basis of energy considerations. Indirect evidence indicates that kinetic factors, including processes occurring at steps propagating across the surface in the two-dimensional growth mode, control ordering. In this work, GaAs{sub 1{minus}{ital x}}P{sub {ital x}} layers have been grown by OMVPE on (001)-oriented GaAs{sub 0.6}P{sub 0.4} substrates.'' In order to examine the effects of surface kinetic factors, the substrates were first patterned with (110)-oriented grooves 5 {mu}m wide and a fraction of a micron deep. The groove is used to provide a source of steps moving in opposite directions from the two edges. Transmission electron diffraction reveals the formation of large domains of the two variants that meet in the center of the groove. A surprising feature is the presence of a region in the groove with absolutely no ordering. Tracing the surface shape during growth using a superlattice structure indicates that the disordered region is due to growth on {l brace}511{r brace} facets. The domains formed after the groove is filled are very large, several square microns in cross-sectional area and extending along the entire length of the groove. These results demonstrate that natural ordering in GaAsP, an alloy with mixing on the group V sublattice, can be controlled by regulating the propagation of steps during growth, exactly as for GaInP where mixing is on the group III sublattice.

• DOE Contract Number: FG02-84ER45061
• OSTI ID: 5993942
• Journal Information: Applied Physics Letters; (United States), Journal Name: Applied Physics Letters; (United States) Vol. 59:25; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
ARSENIC COMPOUNDS
ARSENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
DEPOSITION
ELECTRON MICROSCOPY
EPITAXY
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GALLIUM PHOSPHIDES
KINETICS
MICROSCOPY
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PNICTIDES
SURFACE COATING
SURFACE TREATMENTS
TRANSMISSION ELECTRON MICROSCOPY
VAPOR PHASE EPITAXY