Impact of post-oxidation annealing on low-frequency noise, threshold voltage, and subthreshold swing of p-channel MOSFETs

The impact of post-oxidation annealing on the low-frequency noise, threshold voltage, and subthreshold swing of p-channel MOSFET is reported. The low-frequency noise is improved significantly with post-oxidation annealing and a modest V_T and S reduction is observed. Oxide traps are primarily extracted from measured noise. They are also extracted from threshold voltage and subthreshold slope shift. The contribution of oxide traps to threshold voltage shift and 1/f noise is analyzed through quantitative approach in the light of correlated fluctuation theory. Analysis on experimental results shed light on the well-known controversy about the origin of low-frequency noise, suggesting that experimental results are in agreement with mobility fluctuation theory whereas correlated number fluctuation theory explains the result assuming only a fraction of total oxide charge at a given energy level participates in the generation of low-frequency noise.