In-situ MBE Si as passivating interlayer on GaAs for HfO2 MOSCAP’s: effect of GaAs surface reconstruction

We report a study of MOS capacitors having a dielectric of HfO2 and an interlayer of Si deposited in-situ, by MBE on GaAs surfaces prepared with various surface-reconstructions. Interface state densities of about 1 × 1012 eV−1cm−2 have been obtained. Capacitors on the Ga-rich surface, measured with peripheral illumination, show signs of a possible inversion layer.