Size effects on the DC characteristics and low frequency noise of double polysilicon NPN bipolar transistors

DC and low frequency noise measurements have been carried out for double polysilicon NPN bipolar transistors. Our experiments have highlighted unexpected geometrical dependencies for the base saturation current density and low frequency noise. A model, taking into account a variation of the interfacial oxide thickness at the periphery of the emitter has been proposed and it has been successfully applied to the experimental results.