Control of flatband voltage of Si-based metal-oxide-semiconductor diodes by inclusion of cesium ions in silicon dioxide

The flatband voltage of Si-based metal-oxide-semiconductor diodes can be controlled by the inclusion of cesium (Cs) in SiO2 layers. The inclusion of Cs can be achieved by two methods: (1) spin-on of cesium chloride aqueous solutions, and (2) evaporation of Cs. The maximum flatband voltage shift of similar to0.8 V is achieved by the Cs evaporation method and, in this case, the Cs concentration is estimated to be similar to10(13) atoms/cm(2) from total reflection x-ray fluorospectroscopy measurements. Even when the Cs concentration is as low as similar to10(10) atoms/cm(2), similar to0.1 V flatband voltage shift can be achieved. The net positive charge of Cs decreases with the Cs concentration. (C) 2004 American Institute of Physics.