III-V Compound Semiconductor Native Oxide Mosfets With Focus on Interface Studies.

摘要

The application of Al-bearing III-V compound semiconductor native oxides ton Ga As-based metal oxide semiconductor (MOS) electronic devices has been explored. An insulated-gate buried-channel high electron mobility transistor (HEMT) using an AlGaAs native oxide and modulation-doped InGaAs channel has been demonstrated. InAlP native oxides have been shown to have superior electrical properties compared to those of AlGaAs, with insulating quality comparable to that of SiO2 on Si. We have demonstrated the formation of an inversion layer in heterostructure MOS capacitors employing an InAlP native oxide gate insulator. Transmission electron microscopy has been used to examine the oxide/semiconductor interface region. The use of a thin InGaP oxidation barrier layer is shown to improve native oxide uniformity and electrical quality. The InAlP oxide is found to be sufficiently dense to 'cap' and suppress the oxidation of GaAs. X-ray absorption fine-structure spectroscopy (XAFS) and x-ray reflectivity techniques were applied to III-V native oxides using a beamline at the Argonne National Laboratory Advanced Photon Source. Residual As atoms in oxidized AlGaAs films have been found to be coordinated with oxygen in the form of amorphous As oxides. The density profiles of thin surface-oxidized AlGaAs films are obtained by applying a model-independent fitting method to x- ray reflectivity data.