Correlation between surface structure and ordering in GaInP

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena

DOI:https://doi.org/10.1116/1.589057· OSTI ID:286583

Murata, H; Lee, S H; Ho, I H; Stringfellow, G B ^[1]

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1. Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)

Ga and In atoms in Ga{sub 0.52}In{sub 0.48}P layers spontaneously segregate to form alternating In- and Ga-rich {l_brace}111{r_brace} monolayers during organometallic vapor phase epitaxial (OMVPE) growth on (001) oriented GaAs substrates, thus forming the CuPt ordered structure. This ordering phenomenon is believed to be driven by surface processes, although little direct experimental information is available. This work presents evidence, based on surface photoabsorption data, that [{bar 1}10] oriented P dimers are present on the surface during OMVPE growth using trimethylgallium and ethyldimethylindium combined with tertiarybutylphosphine, suggesting a (2{times}4)-like surface reconstruction. Furthermore, when the growth temperature is increased above 620{degree}C, with other parameters constant, both the concentration of these P dimers and the degree of order are observed to decrease. A similar correlation of decreased P-dimer concentration with decreased degree of order is observed for decreases in V/III ratio. Thus, the changes in order parameter for variations in temperature and TBP flow rate are found to be closely correlated with the changes in the order parameter. A third parameter studied was the misorientation of the substrate from (001) toward either the {l_brace}111{r_brace}{sub {ital A}} or {l_brace}111{r_brace}{sub {ital B}} planes. The concentration of P dimers decreased as the misorientation increased in either direction. The degree of order was also observed to generally decrease, supporting the connection between surface reconstruction and ordering. However, the difference in order parameter observed for the two misorientation directions suggests the importance of a second parameter, the step structure, itself. For exactly (001) oriented substrates the surface was observed, using high resolution atomic force microscopy, to consist of islands, elongated in the [110] direction, with heights of 30{endash}60 A. (Abstract Truncated)

• OSTI ID: 286583
• Report Number(s): CONF-960117--
• Journal Information: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena, Journal Name: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena Journal Issue: 4 Vol. 14; ISSN 0734-211X; ISSN JVTBD9
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
GALLIUM PHOSPHIDES
INDIUM PHOSPHIDES
ORDER-DISORDER TRANSFORMATIONS
PHOTOLUMINESCENCE
SURFACE PROPERTIES
SURFACE RECONSTRUCTION
SURFACE STRUCTURE
TEMPERATURE DEPENDENCE
VAPOR PHASE EPITAXY