DC Performance Variations of SOI FinFETs with Different Silicide Thickness

Abstract

DC performance and the variability of n-type silicon-on-insulator dopant-segregated FinFETs with different silicide thickness (Tsili) are analyzed. DC parameters including threshold voltage, low-field-mobility-related coefficient, and parasitic resistance are extracted from Y-function method for the comparison of DC performance and variability, and the correlation analysis. All the devices show similar subthreshold characteristics, but the devices with thicker Tsili have greater threshold voltages. The devices with thicker Tsili suffer from the DC performance degradation and its greater variations because the Schottky barrier height at the NiSi/Si interface increases and fluctuates greatly. This effect is validated by greater threshold voltages, larger parasitic resistances, and high correlations among all the DC parameters for the thicker Tsili. The devices with thicker Tsili also have higher low-frequency noise because of larger parasitic resistances and their correlated mobility degradations. Therefore, the device with relatively thin Tsili is expected to have better DC performance and variability concerns.