Noise overshoot at drain current kink in SOI MOSFET

The bias dependence of the drain current noise power of SOI (silicon-on-insulator) MOSFETs was studied, and low frequency noise overshoot at the drain current was observed. The overshoot has a width of about 0.7 V and exhibits a peak noise power which is two orders of magnitude higher than the normal noise level. The SOI devices used in this study were N-channel polysilicon gate MOSFETs on SIMOX (separation by implantation of oxygen) wafers fabricated with conventional submicron CMOS technology. The SOI film thickness, the buried-oxide thickness, and the gate oxide are 100 nm, 300 nm, and 11.5 nm, respectively. A computer-controlled test system was used to conduct the I-V and noise measurement automatically. A model explaining the occurrence of the noise overshoot and the noise peak is proposed.<>