Regensburg 2004 – scientific programme

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HL: Halbleiterphysik

HL 27: GaN: Pr
äparation und Charakterisierung

HL 27.13: Talk

Wednesday, March 10, 2004, 18:15–18:30, H15

Silicon doping of heteroepitaxial AlN films grown by MBE — •Martin Hermann, Florian Furtmayr, Martin Stutzmann, and Martin Eickhoff — Walter Schottky Institut, Am Coulombwall 3, 85748 Garching

Recently, Si-doped AlN has attracted increasing interest due to its possible application in wide bandgap semiconductor devices, such as n-AlN/p-diamond heterojunction diodes. So far, these devices suffer from a large serial resistance because of the high ionization energy of Si in AlN. We have investigated Si doping of heteroepitaxial AlN films grown by plasma assisted molecular beam epitaxy.

The influence of the Si concentration on the structural properties has been investigated by high resolution X-ray diffraction measurements. The surface morphology of the AlN:Si samples has been examined by atomic force microscopy. The dependence of the Si donor activation energy on the doping concentration was analyzed by temperature dependent conductivity measurements. Optical absorption measurements were used to detect the formation of impurity induced defects, especially the by Si donor, and to examine their influence on the optical properties of AlN:Si.