N-Channel gallium arsenide MISFET

Abstract

Fabrication processes have been developed for the construction of an n-channel insulated-gate gallium arsenide field effect transistor (MISFET). GaAs-insulator interface properties were investigated from an analysis of MIS characteristics Energy distributions of interface state density were U shape having minimum values near the midgap energy. The minimum values were dependent upon conduction type of substrates amd deposition conditions of insulator films and ranged 1 - 20 \times 10^{11} cm ^-2 eV ^-1 for p-type substrates and 1 - 4 \times 10^{12} cm ^-2 eV ^-1 for n-type substrates. The n ⁺ -regions for source and drain were made by diffusion of tin from the tin-doped silica film or by implantation of silicon ions. The planar passivated diode showed leakage current of less than 1 µA at 5 V reverse bias. An n-channel MISFET was fabricated using above techniques. The maximum field effect mobility of 1480 cm ² V ^-1 sec ^-1 was obtained.