SiO₂/InP Structure Prepared by Direct Photo-Chemical Vapor Deposition Using Deuterium Lamp and Its Applications to Metal-Oxide-Semiconductor Field-Effect Transistor

Abstract

Silicon dioxide ( SiO2) films have been successfully deposited on indium phosphide (InP) substrate at low temperature and low pressure by direct photo-enhanced chemical vapor deposition (photo-CVD) under irradiation by a deuterium lamp. Silane ( SiH4) and oxygen ( O2) are used as reactant sources. The measurements of Fourier transform infrared (FTIR), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) show that the dominant components of the oxide are silicon and oxygen and the film is SiO2. Metal-oxide-semiconductor (MOS) capacitors show sharp interfaces with densities of states in the range of 1.2×1011 cm-2 eV-1. N-channel depletion-mode InP metal-oxide-semiconductor field-effect transistors (MOSFETs) have been fabricated with a transconductance of 63 mS/mm for 2 µ m gate length and an effective channel mobility as high as 1140 cm2 V-1 s-1. High-frequency S-parameter measurements of microwave characteristics for the devices indicate a current-gain cutoff frequency f t=6.3 GHz.