Study of Random Dopant Fluctuation Effects in Germanium-Source Tunnel FETs

Author

Damrongplasit, Nattapol ; Changhwan Shin ; Sung Hwan Kim ; Vega, R.A. ; Tsu-Jae King Liu

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., Univ. of California, Berkeley, CA, USA

Volume

58

Issue

10

fYear

2011

Firstpage

3541

Lastpage

3548

Abstract

The effects of random dopant fluctuations (RDFs) on the performance of Germanium-source tunnel field-effect transistors (TFETs) is studied using 3-D device simulation. The RDF in the source region is found to have the most impact on threshold voltage variation (σV_TH) if the source is moderately doped (10¹⁹ cm^-3) such that vertical tunneling within the source is dominant. If the source is heavily doped (10²⁰ cm^-3) such that lateral tunneling from the source to the channel is dominant, the impact of RDF in the channel region is also significant. RDF-induced threshold voltage variation (σV_TH) for an optimally designed Ge-source TFET is relatively modest (σV_TH <; 20 mV at Lg = 30 nm), compared with a MOSFET of similar gate length. Supply voltage scaling is not beneficial for reducing TFET σV_TH.

Keywords

field effect transistors; fluctuations; tunnel transistors; 3D device simulation; Ge; Ge-source TFET; field-effect transistors; germanium-source tunnel FET; lateral tunneling; random dopant fluctuation effects; supply voltage scaling; threshold voltage variation; vertical tunneling; Doping; Logic gates; Performance evaluation; Resource description framework; Semiconductor process modeling; Transistors; Tunneling; Random dopant fluctuations (RDFs); tunnel field-effect transistor (TFET); tunneling; variability;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2011.2161990

Filename

5985514