Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 73: GaN: Preparation and Characterization IV
HL 73.6: Talk
Thursday, March 29, 2012, 10:45–11:00, ER 270
Investigating Highly Doped Marker Layers in GaN on Sapphire using Scanning Microwave Microscopy — •Matthias A. Fenner1 and Rachel A. Oliver2 — 1Agilent Technologies, Lyoner Straße 20, 60528 Frankfurt, Germany — 2Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK
Gallium nitride films grown on sapphire substrate were investigated using Scanning Microwave Microscopy (SMM). During the growth thin, highly doped layers were included to mark the shape of the surface at regular intervals. The SMM*s capability to measure dopant densities was employed to reconstruct cross sections of these surfaces. An unintentionally doped region was found for the initial stages of the growth. The growth surface at this stage is rough with most parts of the surface tilted out of the substrate plane. This suggests a model in which inclined surfaces promote the unintentional uptake of dopant material. Later stages of the growth result in smooth surfaces without unintentional doping.