Hall mobility in hafnium oxide based MOSFETs: charge effects

The Hall effect is used to measure the electron mobility in HfO/sub 2/ based n-channel field effect transistors with poly-Si gates. Large deviations between measured Hall and drift mobilities are explained by the presence of high concentrations of nonfixed charge (up to 4/spl times/10/sup 12/ cm/sup -2/). Simulated mobility curves show that the observed concentrations of fixed and nonfixed charge can estimate the measured mobility significantly better than if only the fixed charge concentration is used.