SPICE models for flicker noise in p-MOSFETs in the saturation region

The number fluctuation theory based on the McWhorter´s charge-trapping model and the bulk mobility fluctuation theory based on Hooge´s hypothesis are the two major existing theories to explain the origins of the flicker noise, which is the dominant low-frequency noise source in silicon metal-oxide-semiconductor field-effect transistors (MOSFETs). We have done the flicker noise measurements and SPICE simulations for both long-channel (5 μm) and short-channel (1.2 μm and 0.6 μm) p-type channel metal-oxide-semiconductor (PMOS) transistors. HSPICE [device model: level 3, level 46 (BSIM 3v2) and level 47 (BSIM 3v3); noise model: NLEV=0 and NLEV=2 and 3] and PSPICE [device model: level 3, level 6 (BSIM 3v2) and level 7 (BSIM 3v3); noise model: NLEV=0 and NLEV=2 and 3] were used for the simulations. Our measurement results suggest that in the saturation region, for long-channel PMOS transistors, the flicker noise is due to the bulk effect and it follows the mobility fluctuation theory, while for short-channel ones, it is due to the surface state effect and the number fluctuation theory applies. Our simulation results showed that for both HSPICE and PSPICE, level 3 and NLEV=0 are the appropriate models for the simulations of long-channel PMOS transistor flicker noise; HSPICE with level 47 or 49 and NLEV=2 and 3 and PSPICE with level 6 and NLEV=2 and 3 are applied for the short-channel PMOS devices. The simulation results are consistent with the measurements