Evaluation of 1/f Noise Characteristics in High-k/Metal Gate and SiON/Poly-Si Gate MOSFET with 65nm CMOS Process

Abstract

In this paper, we compare 1/f noise characteristics of High-k/Metal Gate MOSFET and SiON/Poly-Si Gate MOSFET experimentally, and evaluate the time fluctuation of drive current. These MOSFETs are fabricated with 65nm CMOS process, and their gate lengths (Lg) are 130nm. Specifically, we focus on the dependency of the time fluctuation of drive current on channel width (W) and temperature (T). First, we evaluate the dependency on channel width. In the case of SiON/Poly-Si Gate MOSFET, when the channel width is narrow such as W=200nm and W=250nm, Power Spectrum Density (PSD) depends on 1/f² at two frequency regions. Moreover, as the channel width is wide such as W=300nm, W=500nm and W=1000nm, PSD depends on 1/f and the value of PSD shifts lower. This is a new phenomena observed for the first time. On the other hand, in the case of High-k/Metal Gate MOSFET, the value of PSD is about 100 times larger than that of SiON/Poly-Si Gate MOSFET. Moreover, there is no dependency of PSD on channel width ranges from 150nm to 1000nm. Second, we evaluate the dependency on temperature. In the case of SiON/Poly-Si Gate MOSFET, when the temperature (T) is lowered from T=27°C to T=-35°C, the dependency changes from the 1/f dependency to the 1/f² dependency at two different frequency regions. This is also a new phenomena observed for the first time. However, in the case of High-k/Metal Gate MOSFET, there is no dependency of PSD on temperature ranges from 27°C to -35°C. These results are useful knowledge for designing future LSI, because PSD dependency shows different characteristics when both channel width and temperature are changed.