Session 12: Nano Device Technology Negative Capacitance and New Material MOSFETs

Tuesday, December 6, 9:00 a.m.
Continental Ballroom 5
Co-Chairs: David Esseni, University of Udine
Takahiro Mori, National Institute of Advanced Industrial Science and Technology

9:05 AM
12.1 Physical Thickness 1.x nm Ferroelectric HfZrOx Negative Capacitance FETs, M.-H. Lee, S. T. Fan*, C.-H. Tang, P.-G. Chen, Y.-C. Chou, H.-H. Chen, J.-Y. Kuo, M.-J. Xie, S.-N. Liu, M.-H. Liao*, C.-A. Jong**, K.-S. Li**, M.-C. Chen**, C. W. Liu*, National Taiwan Normal University , *National Taiwan University, **National Nano Device Laboratories

Ferroelectric HfZrOx (FE-HZO) negative capacitance (NC) FETs is experimentally demonstrated with physical thickness 1.5 nm, SS = 52 mV/dec, hysteresis free (threshold voltage shift = 0.8 mV), and 0.65 nm CET (capacitance equivalent thickness). The NC-FinFET modeling is validated on standard 14nm FinFET. The transient behavior of gate and drain current response are exhibited with triangular gate voltage sweep. The dynamic NC model with compact equivalent circuit for ultra-thin FE-HZO is established with experimental data validation, and estimates the fast response. A feasible concept of coupling the ultra-thin FE-HZO (1.x nm) with NC as gate stack paves a promising solution for sub-10nm technology node.

9:30 AM
12.2 Ferroelectric HfZrOx Ge and GeSn PMOSFETs with Sub-60 mV/decade Subthreshold Swing, Negligible Hysteresis, and Improved IDS, J. Zhou, G. Han, Q. Li, Y. Peng, X. Lu, C. Zhang, J. Zhang, Q.-Q. Sun*, D. W. Zhang* and Y. Hao, Xidian University, *Fudan University

We report the first ferroelectric (FE) HfZrOx (HZO) Ge and GeSn pMOSFETs with sub-60 mV/decade subthreshold swing (SS) (40~43 mV/decade), negligible hysteresis, and enhanced IDS. With a RTA at 450 oC, FE devices with reduced hysteresis of 40~60 mV demonstrate the significantly improved SS and IDS characteristics compared to control devices without FE, owing to the negative capacitance (NC) effect induced by HZO. FE Ge and GeSn pFETs achieve 22% and 20% IDS enhancement than control devices, respectively, at the drive voltage of 1.0 V. NC effect in FE devices is proved by the gate leakage and inversion capacitance characteristics.

9:55 AM
12.3 Experimental Study on Polarization-Limited Operation Speed of Negative Capacitance FET with Ferroelectric HfO2, M. Kobayashi, N. Ueyama, K. Jang and T. Hiramoto, The University of Tokyo

We have experimentally investigated the polarization-limited operation speed of Negative Capacitance FET (NCFET) through direct measurement of negative capacitance in transient characteristics and physics-based modeling, for the first time. Systematic analysis enabled accurate parameter extraction. Our newly developed time-dependent NCFET model provided the evidence that NCFET can operate at >MHz.

10:20 AM
12.4 Fully Coupled 3-D Device Simulation of Negative Capacitance FinFETs for Sub 10 nm Integration, H. Ota, T. Ikegami, J. Hattori, K. Fukuda, S. Migita and A. Toriumi, The University of Tokyo

Performances of negative capacitance FinFETs (NC- FinFETs) at sub 10 nm gate length are analyzed with a newly developed technology computer-aided design (TCAD) simulation. This simulation fully couples the Landau-Khalatnikov (L-K) equation with the physical equations for FinFETs in 3-D. It reveals an excellent immunity against short-channel effects in NC-FinFETs owing to NC-enhancement by the gate- to-drain coupling, for the first time. NC-FinFETs with a gate length of 10 nm are projected to operate with more than 26 times energy-efficiency of conventional FinFETs.

10:45 AM
12.5 Impact of La2O3/InGaAs MOS Interface on InGaAs MOSFET Performance and its Application to InGaAs Negative Capacitance FET, C.-Y. Chang, K. Endo, K. Kato, C. Yokoyama, M. Takenaka and S. Takagi, The University of Tokyo

The impact of La2O3/InGaAs MOS interfaces on the performance of InGaAs MOSFETs and the physical origins are systematically investigated. It is found that La2O3/InGaAs MOSFETs exhibit lower S. S. and lower carrier trapping properties, while have lower mobility than Al2O3/InGaAs MOSFETs because of higher fixed oxide charge density. Also, it is experimentally found for the first time that ALD La2O3 films with thermal budget lower than 300oC have ferroelectricity in W/La2O3/InGaAs MOS and W/La2O3/W MIM structures. The steep slope characteristics due to the negative capacitance effect have been demonstrated, for the first time, in W/La2O3(15nm)/InGaAs MOSFETs.

11:10 AM
12.6 Experimental Study on Hole and Electron Effective Masses in Inversion Layers of Ge (100), (110) and (111) p- and n-MOSFETs, R. Zhang, J. Li, Z. Zheng, X. Yu, W. Dong and Y. Zhao, Zhejiang University

The effective masses of hole and electron in the inversion layers have been quantitatively characterized for Ge p- and n-MOSFETs with Shubnikov–de Haas oscillation measurements. It was found that the effective mass clearly increased with a larger Ns for both hole and electron in (100)/(110)/(111) Ge p and n-MOSFETs.