Electrical and Optical Characterization of GeON Layers with High-ĸ Gate Stacks on Germanium for Future MOSFETs

GeON has been investigated as an interfacial layer for high-k gate stacks. Thermally grown GeON layers have been prepared at 550oC and compared with plasma GeON layers prepared at 300oC, The optical band gap of thermally-grown GeON was also determined by spectroscopic ellipsometry to be 4.86 eV. Electrical characterisation of MOS capacitors has yielded interface state densities (Dit) of less than 1012 cm-2eV-1 for all devices using the conductance method.