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

The number fluctuation theory based on the McWhorter's charge-trapping mode l 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-s emiconductor field-effect transistors (MOSFETs). We have done the flicker n oise measurements and SPICE simulations for both long-channel (5 mum) and s hort-channel (1.2 mum and 0.6 mum) 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 mo del: NLEV = 0 and NLEV = 2 and 3] were used fur the simulations. Our measur ement results suggest that in the saturation region, for long-channel PMOS transistors, the nicker 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 simulat ion results showed that For both HSPICE and PSPICE, level 3 and NLEV = 0 ar e the appropriate models for the simulations of long-channel PMOS transisto r nicker noise; HSPICE with level 47 or 49 and NLEV = 2 and 3 and PSPICE wi th level 6 and NLEV = 2 and 3 are applied for the short-channel PMOS device s. The simulation results are consistent with the measurements.