2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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Clean Technology 2008

Comprehensive Examination of Threshold Voltage Fluctuations in Nanoscale Planar MOSFET and Bulk FinFET Devices

C-H Hwang, H-W Cheng, T-C Yeh, T-Y Li, H-M Huang, Y. Li
National Chiao Tung University, TW

Keywords:
random dopant, process variation, fluctuation, high-k material, nanoscale transistor

Abstract:
Impact of the intrinsic fluctuations on device characteristics, such as the threshold voltage (Vth) fluctuation is crucial in determining the behavior of nanoscale semiconductor devices. The fluctuations are pronounced for continuously shrunk CMOS devices. To alleviate the Vth fluctuation, application of high- dielectric materials, such as HfO2, HfSiO, ZrO2, TiO2, and (Ba, Sr)TiO3 becomes a key to enhancing the performance of device. Field effect transistors (FETs) with vertical channel structure, such as fin-typed FETs, exhibit improved channel controllability over conventional planar devices. It is thus important to examine the effectiveness of fluctuation suppression and mechanism against fluctuation of these two approaches.In this paper, the dependency of process-variation and random-dopant-induced Vth fluctuation on the gate oxide thickness scaling in 16nm MOSFETs is investigated. Fluctuations of the Vth for the studied planar MOSFETs with equivalent oxide thicknesses (EOT) from 1.2nm to 0.2nm are then compared with the results of 16nm bulk fin-typed filed effect transistors (FinFETs). An experimentally validated simulation is conducted to investigate the fluctuation property.


Nanotech 2008 Conference Program Abstract