Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

Fundamental Tradeoff between Conductance and Subthreshold Swing Voltage for Barrier Thickness Modulation in Tunnel Field Effect Transistors

Sapan Agarwal and Eli Yablonovitch

EECS Department
University of California, Berkeley
Technical Report No. UCB/EECS-2014-6
January 23, 2014

http://www.eecs.berkeley.edu/Pubs/TechRpts/2014/EECS-2014-6.pdf

There is a fundamental tradeoff between conductance and subthreshold swing voltage in tunnel field effect transistors that achieve a sharp turn off by modulating the tunnel barrier thickness. At high conductivities, the voltage bias has little control over the tunneling probability. Unfortunately, this results in a poor subthreshold swing voltage at high conductivities. In tunnel field effect transistors, the best sub 60mV/decade results occur only at very low current densities around 1nA/μm. At higher current densities the subthreshold swing voltage is observed to be much worse than 60mV/decade. We show that this is an inherent problem in quantum barrier thickness modulation, and that a different mechanism, band-edge energy filtering, is needed.


BibTeX citation:

@techreport{Agarwal:EECS-2014-6,
    Author = {Agarwal, Sapan and Yablonovitch, Eli},
    Title = {Fundamental Tradeoff between Conductance and Subthreshold Swing Voltage for Barrier Thickness Modulation in Tunnel Field Effect Transistors},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {2014},
    Month = {Jan},
    URL = {http://www.eecs.berkeley.edu/Pubs/TechRpts/2014/EECS-2014-6.html},
    Number = {UCB/EECS-2014-6},
    Abstract = {There is a fundamental tradeoff between conductance and subthreshold swing voltage in tunnel field effect transistors that achieve a sharp turn off by modulating the tunnel barrier thickness. At high conductivities, the voltage bias has little control over the tunneling probability. Unfortunately, this results in a poor subthreshold swing voltage at high conductivities. In tunnel field effect transistors, the best sub 60mV/decade results occur only at very low current densities around 1nA/μm. At higher current densities the subthreshold swing voltage is observed to be much worse than 60mV/decade. We show that this is an inherent problem in quantum barrier thickness modulation, and that a different mechanism, band-edge energy filtering, is needed.}
}

EndNote citation:

%0 Report
%A Agarwal, Sapan
%A Yablonovitch, Eli
%T Fundamental Tradeoff between Conductance and Subthreshold Swing Voltage for Barrier Thickness Modulation in Tunnel Field Effect Transistors
%I EECS Department, University of California, Berkeley
%D 2014
%8 January 23
%@ UCB/EECS-2014-6
%U http://www.eecs.berkeley.edu/Pubs/TechRpts/2014/EECS-2014-6.html
%F Agarwal:EECS-2014-6