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HL: Halbleiterphysik

HL 24: GaN: Pr
äparation und Charakterisierung I

HL 24.6: Vortrag

Dienstag, 25. März 2003, 16:30–16:45, BEY/118

Hydrogen sensitivity of Pt and Pd Schottky diodes on GaN and AlGaN — •O. Weidemann, M. Hermann, G. Steinhoff, M. Stutzmann, and M. Eickhoff — Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, 85748 Garching, Germany

The chemical and thermal stability of GaN and AlGaN makes them promising materials for devices operating under harsh environments and high temperatures. This stability is of great interest especially for gas sensing applications like monitoring of hydrogen and hydrocarbons in combustion processes. Pt and Pd Schottky diodes have been processed on MBE-grown GaN- and AlGaN- films of both polarities and with various Al contents after different surface treatments, such as thermal and anodic oxidation. The electronic properties of the resulting diodes have been compared with in-situ Pd contacts evaporated in the UHV directly after growth to prevent formation of a native oxide at the interface. AFM, XPS, IV and CV techniques were used to characterize these devices. The results are discussed and compared with the sensitivity and transient behavior of the response to hydrogen at different temperatures.