Random work functions induced DC and dynamic characteristic fluctuations in 16-nm high-κ/metal gate CMOS device and digital circuit

We study nanosized metal grains induced DC and timing fluctuations in 16 nm high-κ/metal gate (HKMG) MOSFET devices. A localized work function fluctuation (LWKF) on device's DC/AC and CMOS inverter's characteristics is advanced using an experimentally validated 3D device simulation which cannot be well modeled using an averaged WKF (AWKF) method. DC characteristics estimated by the LWKF method are 1.5 and 1.6 times larger than that by the AWKF method for N- and P-MOSFETs, respectively, due to random grain number and position effects. The delay time of high-to-low and low-to-high of the CMOS inverter calculated by the AWKF method are underestimated by 1.29 and 1.19 times, compared with the LWKF method.