Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 7: III-V semiconductors I
HL 7.4: Vortrag
Montag, 26. März 2007, 11:45–12:00, H17
In-N anti-correlation in InGaAsN alloys: the delicate interplay between adatom thermodynamics and kinetics — •Hazem Abu-Farsakh1,2 and Jörg Neugebauer1,2 — 1Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany — 2Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
Quaternary InGaAsN alloys have sparked a lot of interest in making infrared laser diodes for optical data transmission. Recent growth experiments showed a complex behavior for this quaternary system, such as In-N anti-correlation and a tendency to 3D growth with increasing growth temperature. The underlying mechanisms, however, could not be identified so far. We have therefore performed an extensive theoretical study to identify and quantify the fundamental growth mechanisms. Specifically, we computed the incorporation/solubility of N at GaAs and InGaAs surfaces employing density functional theory within the PAW approach. Based on theses results, we (i) derive the thermodynamics phase diagram for N incorporation into the experimentally relevant surface reconstructions, and (ii) identify the kinetic processes for N incorporation at different surface and subsurface sites. Based on these results we have been able to interpret recent experiments and to identify suitable growth conditions.