A Study of the Effect of V/III Flux Ratio and Substrate Temperature on the in Incorporation Efficiency in InxGa1−x/GaN Heterostructures Grown by RF Plasma-Assisted Molecular Beam Epitaxy

Autor: R. J. Hauenstein, F. Fedler, M. L. O’Steen
Rok vydání: 2000
Předmět:
Zdroj: MRS Internet Journal of Nitride Semiconductor Research. 5:167-173
ISSN: 1092-5783
DOI: 10.1557/s1092578300004233
Popis: Laterally resolved high resolution X-ray diffraction (HRXRD) and photoluminescence spectroscopy (PL) have been used to assess In incorporation efficiency in InxGa1−xN/GaN heterostructures grown through rf-plasma-assisted molecular beam epitaxy. Average alloy composition over a set of InxGa1−xN/GaN superlattices has been found to depend systematically upon both substrate temperature (Tsub) and V/III flux ratio during growth. A pronounced thermally activated In loss (with more than an order-of-magnitude decrease in average alloy composition) is observed over a narrow temperature range (590–670°C), with V/III flux ratio fixed. Additionally, the V/III flux ratio is observed to further strongly affect In incorporation efficiency for samples grown at high Tsub, with up to an order-of-magnitude enhancement in In content despite only a minor increase in V/III flux ratio. PL spectra reveal redshifts as In content is increased and luminescence efficiency which degrades rapidly with decreasing Tsub. Results are consistent with In loss arising from thermally activated surface segregation + surface desorption processes during growth.
Databáze: OpenAIRE