Selective area growth of GaAs with semiconductor-metal-semiconductor structures using pulsed-mode operation of MOCVD

Abstract

Selective area growth of GaAs with semiconductor-metal-semiconductor structures using pulsed-mode operation of MOCVD, which controls the flow of trymethylgallium (TMG) at regular intervals, is reported. GaAs is selectively grown over tungsten gratings on (100) GaAs substrates. Tungsten gratings are masked with SiO2 for the selective growth and it is possible to have good GaAs growth over W gratings without keeping the substrate temperature high and the growth rate low. The ideality factor and the barrier height of the W-GaAs Schottky diode in-situ annealed under the growth conditions show slight degradation with increased growth time. Using double crystal x-ray diffractometer and Auger electron spectroscopy analysis, it is shown that the interdiffusion of W and GaAs takes place. A vertical FET is fabricated to show the device application of this selective growth method.