Effects of InP Surface Treatment on the Electrical Properties and Structures of AlN/n-InP Interface

Abstract
We investigated the effects of InP surface pretreatment on the electrical properties and structures of the MOCVD-AlN/n-InP interface. AlN films were deposited at 370°C on n-InP substrates after a thermal pretreatment in PH3 or AsH3 ambient. The frequency dispersion in the C-V (capacitance-voltage) characteristics of AlN/n-InP MIS diodes was suppressed by a thermal pretreatment in AsH3 ambient. The grazing incidence X-ray diffraction measurements revealed a 2×1 superstructure for the AsH3-pretreatment case at the interface between InP and AlN deposited at 220°C. The present results imply that AsH3 pretreatment should result in an As-terminated InP surface.
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