Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 34: Poster I: III-V Semiconductors
HL 34.19: Poster
Dienstag, 23. März 2010, 18:30–20:30, Poster D2
Growth and Doping of AlGaN in MOVPE — •Igor Kuznecov, Joachim Stellmach, Markus Pristovsek, and Michael Kneissl — TU Berlin, Institute of Solid State Physics, Hardenbergstr. 36, 10623 Berlin, Germany
There are numerous applications for ultraviolet (UV) light like water disinfection. Especially around 265 nm the DNA is most sensitive. To achieve this wavelength AlGaN light-emitting diodes (LEDs) with aluminium contents up to 60 % are required. However, for n-doped AlGaN the silicon ionization energy increases from 17 meV for GaN up to 50 meV for Al0.4Ga0.6N. The increase in aluminium content is accompanied by the increase in concentration of centers deeper then silicon that have to be filled with electrons before the Fermi level can be shifted to the silicon donor level [1].
Silicon doped AlxGa1−xN (0≤x≤0.4) layers have been grown on AlN/sapphire templates in a close-coupled showerhead (CCS) metalorganic vapour phase epitaxy (MOVPE) reactor. The influence of two key parameters reactor pressure and chamber height, i.e. the distance between showerhead and susceptor were investigated. The aluminium content was estimated with x-ray diffraction. Carrier concentrations and mobilities have been determined with temperature dependent Hall measurements. The surface quality was studied with atomic force microscopy (AFM).
[1] A. Polyakov, et al., Solid-State Electronics 42 (1998) 627