Doping, Tunnel Barriers, and Cold Carriers in InAs and InSb Nanowire Tunnel Transistors

Author

Sylvia, Somaia Sarwat ; Khayer, M. Abul ; Alam, Khairul ; Lake, Roger K.

Author_Institution

Dept. of Electr. Eng., Univ. of California, Riverside, CA, USA

Volume

59

Issue

11

fYear

2012

Firstpage

2996

Lastpage

3001

Abstract

InAs and InSb nanowire tunnel field-effect transistors require highly degenerate source doping to support the high electric fields in the tunnel region. For a target on-current of 1 μA, the source Fermi energy lies in the range of 0.1-0.22 eV below the valence band edge depending on the material and diameter. Despite the large degeneracy, the devices achieve minimum inverse subthreshold slopes of ~ 30 mV/dec. In the subthreshold, these devices experience both regimes of “voltage-controlled tunneling” and “cold-carrier injection.” The reduction of the inverse subthreshold slope from each of these two processes is quantified. Numerical results based on a discretized eight-band k-p model are compared to analytical WKB theory. The standard WKB theory gives good qualitative agreement with the full-band numerical simulations.

Keywords

Fermi level; field effect transistors; indium compounds; nanowires; semiconductor doping; tunnel transistors; tunnelling; InAs; InAs nanowire tunnel FET; InSb; InSb nanowire tunnel FET; cold-carrier injection; current 1 muA; discretized eight-band k-p model; doping; electron volt energy 0.1 eV to 0.22 eV; field-effect transistors; source Fermi energy; tunnel barriers; voltage-controlled tunneling; Doping; Logic gates; Photonic band gap; Quantum capacitance; Standards; Transistors; Tunneling; Cold-carrier injection; InAs nanowire (NW); InSb NW; inverse subthreshold slope; tunnel field-effect transistor (TFET); voltage-controlled tunneling;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2012.2212442

Filename

6304912