Indium incorporation mechanism during InGaN growth by plasma-assisted molecular beam epitaxy
|Henryk Turski 1, Marcin Siekacz 1,2, Grzegorz Muzioł 1, Marta Sawicka 1,2, Sylwester Porowski 1, Czeslaw Skierbiszewski|
1. Polish Academy of Sciences, Institute of High Pressure Physics (UNIPRESS), Sokolowska 29/37, Warszawa 01-142, Poland
The prospects for InGaN in optoelectronic applications are excellent due to the wide range of accessible band gap covering the whole visible light spectrum. However the growth of high quality InGaN with indium (In) concentrations of more than 20% (imperative for long wavelength emitters) is still challenging. Growth of high optical quality InGaN structures has been recently demonstrated on c-plane GaN in excess of In flux by plasma-assisted molecular beam epitaxy (PAMBE)  at considerably lower temperatures then those used in MOVPE. It has been also established that In content can be increased by decreasing the growth temperature  or decreasing miscut angle of a substrate .
In this work we study the mechanism of In incorporation into InGaN layers in PAMBE environment. Based on experimental data obtained for structures grown using different Ga and N fluxes, a phenomenological model of InGaN growth was proposed. We found that both Ga and N fluxes influence composition and morphology of InGaN layers. This effect is explained by the growth kinetic dependence of the decomposition rate of In-N fraction . The functional dependence of In content on atomic fluxes is deduced taking into account the existence of nonequivalent growth nucleation centers on neighboring atomic steps for InGaN surface. This observation, previously reported for GaN , has significant consequences for the InGaN growth.
We will discuss the model predictions for the maximum indium content of InGaN layers grown at a given growth temperature and show the proper conditions for the growth of efficient high indium content quantum wells.
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Acknowledgements: This work was supported partially by the National Science Centre Grant No. 02938, the National Centre for Research and Development Grant No. IT13426, INNOTECH 157829, and the European Union within European Regional Development Fund, through the Innovative Economy Grant No. POIG.01.01.02-00-008/08, and the European Union funds within the European Social Fund.
Presentation: Oral at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, General Session 10, by Henryk Turski
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17
Submitted: 2013-04-15 16:11 Revised: 2013-04-15 16:41