The Tunneling Field-Effect Transistor (TFET) has shown promise as a possible replacement for the MOSFET, especially in low power applications where power supplies continue to shrink. One of the biggest developmental challenges with the TFET is the relatively low drive current density compared to that of a MOSFET. Increasing tunneling probability will increase drive current density. Determining the peak current density in a tunnel diode can give insight into the tunneling probability for the material system. This can then be used to predict what material systems might support high current density TFETs.
This study focuses on the InAs/GaSb broken gap system. Heterojunction Tunnel Diodes (HTDs) and Resonant Interband Tunnel Diodes (RITDs) were fabricated from Molecular Beam Epitaxy (MBE) grown substrates using varying doping concentrations, including undoped. The HTD devices were designed to investigate the effect doping has on peak current density. To determine a minimum current density, an undoped HTD was fabricated. The RITDs were designed to investigate an alternative structure and determine if it could be used to further improve peak current density.
This study has shown that changes in dopant concentration only have a significant impact on tunneling current when the dopants are near the junction. No differences in current density was observed between the four HTD samples. The undoped sample exhibited an average peak current density of 16 kA/cm^2. The RITD samples did not show any significant differences in peak current density with varying well width. Additionally, the control HTD device performed significantly better, in terms of peak current density, than any of the RITD samples.
Library of Congress Subject Headings
Tunnel diodes--Testing; Field-effect transistors--Design and construction; Field-effect transistors--Materials
Microelectronic Engineering (MS)
Department, Program, or Center
Microelectronic Engineering (KGCOE)
Filmer, Matthew J., "InAs/GaSb Tunnel Diodes" (2015). Thesis. Rochester Institute of Technology. Accessed from
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