Properties of SiO₂/Si/GaAs structures formed by solid phase epitaxy of amorphous Si on GaAs

We have achieved solid phase epitaxy of thin amorphous Si layers on GaAs using in situ plasma processing and subsequent annealing. High-resolution transmission electron microscopy of the SiO2/Si/GaAs structure shows that a Si layer ≅20 Å thick epitaxially crystallizes on GaAs after annealing at ≅570°C in N2. Metal-oxide-semiconductor capacitors fabricated on these structures confirm the high quality of these interfaces. By comparing a high- frequency (100 kHz) capacitance-voltage curve with a quasi-static one, interface state densities as low as 4×10 12 eV-1/cm-2 were measured on both n- and p-type GaAs.