THE INFLUENCE OF OXIDATION TEMPERATURE AND GATE METAL ON THE ELECTRICAL-PROPERTIES OF INP METAL-INSULATOR-SEMICONDUCTOR TUNNEL-DIODES

The electrical properties of InP metal-insulator-semiconductor (MIS) diodes with a thermally grown oxide interfacial layer were investigated. The oxidation temperatures were 400 degrees C, 450 degrees C and 500 degrees C, and gate metals were Al, Au, Cu, and Pt. Diodes with interfacial layers grown at 450 degrees C showed better characteristics. The parameters under investigation were barrier height, ideality factor and interface state density. Diodes with interfacial layers grown at 500 degrees C had poor characteristics. In diodes with interfacial layers grown at 400 degrees C and 450 degrees C the barrier height varied linearly with the metal work function. The pileup of phosphorus atoms at the oxide-InP interface and presence of an indium-rich oxide layer next to the metal at higher oxidation temperature and metal-oxide reaction were used to explain the observations.