Bi surfactant control of ordering and surface structure in GaInP grown by organometallic vapor phase epitaxy
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)
- Department of Materials Science and Engineering, Kwangju Institute of Science and Technology, Kwangju 506-712, Korea (Korea, Republic of)
The surfactant Bi has been added during organometallic vapor phase epitaxial growth (OMVPE) of GaInP using the precursor trimethylbismuth. The addition of a small amount of Bi during growth results in disordered material using conditions that would otherwise produce highly ordered GaInP. Significant changes in the surface structure are observed to accompany the disordering. Atomic force microscopy measurements show that Bi causes an order of magnitude increase in step velocity, leading to the complete elimination of three-dimensional islands for growth on singular (001) GaAs substrates, and a significant reduction in surface roughness. Surface photoabsorption measurements indicate that Bi reduces the number of [1(bar sign)10] P dimers on the surface. Secondary ion mass spectroscopy measurements reveal that the Bi is rejected from the bulk, even though it changes the surface reconstruction. Clearly, Bi acts as a surfactant during OMVPE growth of GaInP. The difference in band gap energy caused by the reduction in order parameter during growth is measured using photoluminescence to be about 110 meV for layers grown on singular substrates. Disorder/order/disorder heterostructures were successfully produced in GaInP with a constant solid composition by modulating the TMBi flow rate during growth. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20217678
- Journal Information:
- Journal of Applied Physics, Vol. 88, Issue 7; Other Information: PBD: 1 Oct 2000; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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