Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 33: GaN: Preparation and characterization
HL 33.11: Vortrag
Mittwoch, 29. März 2006, 17:00–17:15, BEY 154
Optical investigations of the lateral homogeneity of InGaN MQW heterostructures on 2 inch wafers — •Christoph Hums1, Armin Dadgar1,2, Jürgen Bläsing1, and Alois Krost1 — 1Otto-von-Guericke Universität Magdeburg, Fakultät für Naturwissenschaften, Institut für Experimentelle Physik, Universitätplatz 2, 39106 Magdeburg — 2AZZURRO Semiconductor AG, Universitätplatz 2, 39106 Magdeburg
The growth of ternary In-containing alloys is a very temperature sensitive process since small variations in temperature lead to large variations in the In-content and to a small part in the growth rate. A main source for temperature inhomogeneities of the wafer surface in MOVPE growth is the bowing of the wafer induced by strain and the vertical temperature gradient . The optical properties of the sample are effected strongly by Indium content, InGaN-QW layer thickness and overall layer thickness of the structure and have been investigated with spatially resolved photoluminescence. As sample basis we used entire 2 inch wafers from a production type and a research reactor. The peak energy, e.g., shows a standard deviation of ~15meV at a center energy of 2.783eV. Fabry-Perot oscillations are well visible at yellow luminescence energies. These thickness interferences have an influence on the luminescence intensity and peak energies of the InGaN related luminescence. To determine the influence of the interferences the overall layer thickness has been measured spatially resolved and compared with the PL properties. We discuss the possible impact of wafer bowing on temperature and In inhomogeneities.