Effect of surface nitridation on the Ge/HfO2 interface
Abstract
Effect of Ge surface nitridation, prior to HfO2 deposition, on Ge/HfO2 interface has been studied using low temperature measurements. C-V characteristics at room temperature show significant dispersion in nitrided devices compared to non-nitrided devices as a function of frequency. Electron trapping is found to be dominant as temperature was reduced to 140K. Estimated activation energies in nitrided and non-nitrided devices indicate that surface nitridation is introducing new trap levels in bulk oxide. Constant voltage stress shows hole trapping being dominant in non-nitrided devices. In nitrided devices, effect of both hole and electron trapping is observed at higher stress level and higher charge injection. copyright The Electrochemical Society.