Session 6 – TAPA 1

Low Power and Steep Subthreshold Technology

 

Tuesday, June 12, 3:25 p.m.

Chairs:                  A. Seabaugh, Notre Dame Univ.

                                T. Iwamatsu, Renesas Electronics Corp.

6.1 – 3:25 p.m.

Recent Progress and Challenges for Relay Logic Switch Technology (Invited), T.-J. King Liu, L. Hutin, I-R. Chen, R. Nathanael, Y. Chen, E. Alon, University of California, Berkeley

The energy efficiency of CMOS technology is fundamentally limited by transistor off-state leakage (Ioff).  Mechanical switches have zero Ioff and therefore could be advantageous for ultra-low-power digital logic applications.  This paper discusses recent advancements in relay logic switch technology and current challenges which must be addressed to realize its promise.

6.2 – 3:50 p.m.

III-V Field Effect Transistors for Future Ultra-Low Power Applications (Invited), G. Dewey, B.C. Kung, R. Kotlyar, M. Metz, N. Mukherjee, M. Radosavljevic, Intel Corp.

 

This paper summarizes the electrostatics and performance of III-V field effect transistors including thin body planar MOSFETs, 3-D tri-gate MOSFETs, and Tunneling FETs (TFETs). The electrostatics of the III-V devices is shown to improve from thick body planar to thin body planar and then to 3-D tri-gate. Beyond the MOSFET structures, sub-threshold slope (SS) steeper than 60 mV/decade has been demonstrated in III-V TFETs. These III-V devices, especially the 3-D tri-gate MOSFET and TFET, are viable options for future ultra low power applications.

 

6.3 – 4:15 p.m.

Steep-Slope Tunnel Field-Effect Transistors Using III-V Nanowires/Si Heterojunction (Invited), K. Tomioka, M. Yoshimura, T. Fukui, Hokkaido University

 

In this paper, we report on a tunneling field-effect transistors (TFETs) using III-V nanowire (NW)/Si heterojunctions. We experimentally demonstrate steep turn-on behaviors using the TFET with surrounding-gate architecture and high-k dielectrics. Adjusting series resistances in this device structure is important for achieving steep-slope switching. A minimum subthreshold slope (SS) of the TFET is 21 mV/dec (VDS of 0.10 – 1.00 V) at room temperature.

 

 6.44:40 p.m.

Strained Tunnel FETs with Record Ion:First Demonstration of ETSOI TFETs with SiGe Channel and RSD, A. Villalon, C. Le Royer, M. Cassé, D. Cooper, B. Prévitali, C. Tabone, J.-M. Hartmann, P. Perreau, P. Rivallin, J.-F. Damlencourt, F. Allain, F. Andrieu, O. Weber, O. Faynot, T. Poiroux, CEA, LETI, Minatec

 

We present for the first time Tunnel FETs (TFETs) obtained with a FDSOI CMOS process flow featuring High-K Metal Gate, ultrathin body compressively strained SiGe (Ge content from 0 to 30%) based channels, and SiGe30% Raised SD. We analyse the tunnelling improvements due to the different technological injection boosters: ultrathin body & EOT, strain, low band gap source, and low temperature SD anneal. For the first time, TFETs with large ON current (up to 428µA/µm) are demonstrated (with >x1000 ION gain vs. SOI reference).

 

6.5 5:05 p.m.

Demonstration of Improved Heteroepitaxy, Scaled Gate Stack and Reduced Interface States Enabling Heterojunction Tunnel FETs with High Drive Current and High On-Off Ratio, D. Mohata, B. Rajamohanan, Y. Zhu*, M. Hudait*, R. Southwick*, Z. Chbili**, D. Gundlach**, J. Suehle**, J. Fastenau^, D. Loubychev^, A. Liu^, T. Mayer, V. Narayanan, S. Datta, The Pennsylvania State University, *Virginia Tech, **NIST, ^IQE Inc.

 

Staggered tunnel junction (GaAs0.35Sb0.65 /In0.7Ga0.3As) is used to demonstrate heterojunction tunnel FET (TFET) with the highest drive current, Ion, of 135µA/µm and highest Ion/Ioff ratio of 2.7104 (Vds=0.5V, Von-Voff=1.5V). Effective oxide thickness (EOT) scaling (using Al2O3/HfO2 bilayer gate stack) coupled with pulsed I-V measurements (suppressing Dit response) enable demonstration of steeper switching TFET.