Simulation Study on Dopant Fluctuation Impact on SRG MOSFET Device and Circuit Performane

H. Wang, J. He, Y. Liu
Peking University Shenzhen SOC Key Laboratory, CN

Keywords: surrounding gate MOSFET, random dopant fluctuation, threshold voltage variation, SRAM, static noise margin

Summary:

This paper investigates the impact of random dopant fluctuation on surrounding gate MOSFET, from atomic statistical simulation of device to circuit performance evaluation. The doping profile is generated by an analysis of each lattice atom and then the threshold voltage variation is obtained by device Drift-Diffusion simulation. From it, the circuit performance is evaluation is performed by feeding the result into a surrounding-gate MOSFET model in the circuit simulator. It is shown that a significant fluctuation in threshold voltage is due to volume decreases. The circuit simulation results also reveal that a surrounding gate MOSFET based 6-T SRAM presentes a promising resistibility to noise disturbance compared to the traditional bulk MOSFET.