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

We present characteristics of Al/Si3N4/Si/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.