Metal-oxide-semiconductor structure with Ge nanocrystals for memory devices applications

Metal-oxide-semiconductor structures with germanium nanocrystals embedded in the oxide matrix have been fabricated by rf sputtering followed by rapid thermal annealing. The cross-sectional transmission electron micrographs of the structure provide a clear indication of the formation of isolated germanium nanocrystals sandwiched between tunnelling and cap gate oxides. The optical properties of the structure studied by photoluminescence spectroscopy show the emission in the visible range due to quantum confinement of carriers. The C-V measurements of the trilayer structure have been used to demonstrate the charge storage characteristics in the Ge nanocrystals.