Electrical characteristics of bulk finfet according to spacer length

Abstract

This paper confirms that the electrical characteristics of FinFETs such as the on/off ratio, drain-induced barrier lowering (DIBL), and sub-threshold slope (SS) can be improved by optimizing the FinFET spacer structure. An operating voltage that can maintain a life of 10 years or more when hot-carrier injection is extracted. An excellent on/off ratio (7.73 × 107) and the best SS value were found at 64.29 mV/dec with a spacer length of 90 nm. Under hot carrier-injection conditions, the supply voltages that meet the 10-year lifetime condition are 1.11 V, 1.18 V, and 1.32 V for spacer lengths of 40 nm, 80 nm, and 120 nm, respectively. This experiment confirmed that, even at low drain voltages, the shorter is the spacer length, the greater is the deterioration. However, this increasing maximum operating voltage is very small when compared to the increase in the driving voltage required to achieve similar performance when the spacer length is increased; therefore, the effective life is expected to decrease. The results indicate that structural optimization must be performed to increase the driving current of the FinFET and prevent degradation of the analog performance.