Random Work Functions Induced DC and Dynamic Characteristic Fluctuations in 16-nm High-k/Metal Gate CMOS Device and Digital Circuit

Hui-Wen Cheng and Yiming Li

National Chiao Tung University


This work studies nanosized metal grain induced timing delay fluctuation in 16-nm high-k/metal gate (HKMG) metal-oxide-semiconductor field effect transistor (MOSFET) devices. The estimated localized work function fluctuation (LWKF) on device’s DC, AC characteristics, and inverter is calculated using a 3D device simulation which cannot be well modeled using an averaged WKF (AWKF) method. The results show that the DC characteristics calculated by LWKF method are 1.5 and 1.6 times larger than that by AWKF method for N- and P-MOSFETs, respectively, due to considering grain number and position effects. Further, from a CMOS inverter viewpoint, the high-to-low and low-to high delay time calculated by AWKF method are underestimated by 1.29 and 1.19 times compared with LWKF method.