Interface properties of Si₃N₄/Si/n-GaAs metal-insulator-semiconductor structures grown on GaAs(111)B substrate

We present characteristics of Al/Si₃N₄Si/n-GaAs metal-insulator-semiconductor (MIS) interfaces grown on GaAs(111)B prepared with a combination of in situ molecular beam epitaxy (MBE) and chemical vapor deposition (CVD) techniques. The density of the surface states in the high 10¹⁰ eV^-1 cm^-2 near the GaAs midgap for the GaAs grown at 575 °C and 625 °C was obtained. The MIS structure with GaAs homoepitaxial layer grown at 625 °C, showing smoother surface morphology than the surface grown at 575 °C, exhibited small hysteresis which was as small as 30 mV under a field excursion of 1.5 MV/cm. The presence of a 1 MHz frequency response at 77 K suggests that the traps be within 60 meV of the conduction band edge of GaAs.