An analytical model for 1/f noise in polycrystalline silicon thin films

Noise calculations based on Hooge´s empirical mobility fluctuation model are presented for mobility fluctuations occurring in the quasi-neutral and the depletion-barrier regions of low to moderately doped polycrystalline silicon resistors. Comparing the theoretical predictions with the experimental results, it is concluded from the bias dependence and the magnitude of the noise density that the 1/f noise in polysilicon is depletion-region dominant. The limiting role of grain boundaries, the noise correlation between depletion regions on both sides of a grain boundary, and a noise source weight function are taken into account. The Hooge parameter found from the model and data is 1.45×10^-3