PROPERTIES OF SPIN-ON GLASS AS AN INSULATOR FOR INP METAL-INSULATOR-SEMICONDUCTOR STRUCTURES

The application of Futurrex ICI-200 spin-on glass as an insulator for InP metal-insulator-semiconductor (MIS) structures including InP MIS capacitors and InP MIS field-effect transistors (MISFET's) was investigated. Preliminary measurement of the electrical properties of the spin-on glass were performed using Si MIS structures with the spin-on glass insulator layer. It was found that the spin-on glass which is subjected to a final curing treatment utilizing a rapid-thermal annealing at 600-degrees-C for 5 sec in a O2 ambient exhibits the best electrical properties. However, it was demonstrated by secondary ion mass spectroscopy that when done on InP, the 600-degrees-C rapid-thermal annealing resulted in the outdiffusion of indium and phosphorus into the spin-on glass. The change in the spin-on glass electrical characteristics due to this outdiffusion resulted in an instability in the InP MISFET operation.