METAL-INSULATOR-SEMICONDUCTOR STRUCTURE ON GAAS USING A PSEUDOMORPHICSI GAP INTERLAYER/

We report on a novel GaAs metal-insulator-semiconductor (MIS) structur e exhibiting the interface state densities in the 9.2 x 10(10) eV(-1) cm(-2) with a Si (10 Angstrom)/GaP (12 Angstrom) layer on GaAs. The st ructure was grown by a combination of molecular beam epitaxy and chemi cal vapor deposition. The hysteresis and frequency dispersion of the M IS capacitor were lower than 100 mV, some of them as low as 70 mV unde r a field swing of about +/-1.4 MV/cm. Ex situ solid phase annealing a round 500-550 degrees C in N-2 using rapid thermal annealing was high enough to recrystallize the as-deposited Si interlayer at low temperat ure (similar to 300 degrees C). The 100 kHz frequency response at 77 K suggests that the interface pinning levels are close to the conductio n band edge of GaAs. This article reports the first application of a p seudomorphic Si/GaP interlayer to ideal GaAs MIS diodes and exhibits a favorable interface stability with high temperature annealing. (C) 19 97 American Vacuum Society.