skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure

Abstract

The compositional dependence of effective tunneling barrier height (E{sub beff}) and defect assisted band alignment transition from staggered gap to broken gap in GaAsSb/InGaAs n-channel tunnel field effect transistor (TFET) structures were demonstrated by x-ray photoelectron spectroscopy (XPS). High-resolution x-ray diffraction measurements revealed that the active layers are internally lattice matched. The evolution of defect properties was evaluated using cross-sectional transmission electron microscopy. The defect density at the source/channel heterointerface was controlled by changing the interface properties during growth. By increasing indium (In) and antimony (Sb) alloy compositions from 65% to 70% in In{sub x}Ga{sub 1-x}As and 60% to 65% in GaAs{sub 1-y}Sb{sub y} layers, the E{sub beff} was reduced from 0.30 eV to 0.21 eV, respectively, with the low defect density at the source/channel heterointerface. The transfer characteristics of the fabricated TFET device with an E{sub beff} of 0.21 eV show 2 Multiplication-Sign improvement in ON-state current compared to the device with E{sub beff} of 0.30 eV. On contrary, the value of E{sub beff} was decreased from 0.21 eV to -0.03 eV due to the presence of high defect density at the GaAs{sub 0.35}Sb{sub 0.65}/In{sub 0.7}Ga{sub 0.3}As heterointerface. As a result, the band alignment was converted from staggered gapmore » to broken gap, which leads to 4 orders of magnitude increase in OFF-state leakage current. Therefore, a high quality source/channel interface with a properly selected E{sub beff} and well maintained low defect density is necessary to obtain both high ON-state current and low OFF-state leakage in a mixed As/Sb TFET structure for high-performance and lower-power logic applications.« less

Authors:
; ; ;  [1]; ;  [2]; ; ;  [3];  [4]
  1. Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)
  2. Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania-16802 (United States)
  3. IQE Inc., Bethlehem, Pennsylvania-18015 (United States)
  4. Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)
Publication Date:
OSTI Identifier:
22089573
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 112; Journal Issue: 9; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIMONY; DENSITY; FIELD EFFECT TRANSISTORS; GALLIUM ARSENIDES; HETEROJUNCTIONS; INDIUM ARSENIDES; INTERFACES; LAYERS; LEAKAGE CURRENT; RESOLUTION; SEMICONDUCTOR MATERIALS; TRANSMISSION ELECTRON MICROSCOPY; TUNNEL EFFECT; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Zhu, Y., Jain, N., Vijayaraghavan, S., Hudait, M. K., Mohata, D. K., Datta, S., Lubyshev, D., Fastenau, J. M., Liu, Amy K., and Monsegue, N. Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure. United States: N. p., 2012. Web. doi:10.1063/1.4764880.
Zhu, Y., Jain, N., Vijayaraghavan, S., Hudait, M. K., Mohata, D. K., Datta, S., Lubyshev, D., Fastenau, J. M., Liu, Amy K., & Monsegue, N. Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure. United States. doi:10.1063/1.4764880.
Zhu, Y., Jain, N., Vijayaraghavan, S., Hudait, M. K., Mohata, D. K., Datta, S., Lubyshev, D., Fastenau, J. M., Liu, Amy K., and Monsegue, N. Thu . "Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure". United States. doi:10.1063/1.4764880.
@article{osti_22089573,
title = {Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure},
author = {Zhu, Y. and Jain, N. and Vijayaraghavan, S. and Hudait, M. K. and Mohata, D. K. and Datta, S. and Lubyshev, D. and Fastenau, J. M. and Liu, Amy K. and Monsegue, N.},
abstractNote = {The compositional dependence of effective tunneling barrier height (E{sub beff}) and defect assisted band alignment transition from staggered gap to broken gap in GaAsSb/InGaAs n-channel tunnel field effect transistor (TFET) structures were demonstrated by x-ray photoelectron spectroscopy (XPS). High-resolution x-ray diffraction measurements revealed that the active layers are internally lattice matched. The evolution of defect properties was evaluated using cross-sectional transmission electron microscopy. The defect density at the source/channel heterointerface was controlled by changing the interface properties during growth. By increasing indium (In) and antimony (Sb) alloy compositions from 65% to 70% in In{sub x}Ga{sub 1-x}As and 60% to 65% in GaAs{sub 1-y}Sb{sub y} layers, the E{sub beff} was reduced from 0.30 eV to 0.21 eV, respectively, with the low defect density at the source/channel heterointerface. The transfer characteristics of the fabricated TFET device with an E{sub beff} of 0.21 eV show 2 Multiplication-Sign improvement in ON-state current compared to the device with E{sub beff} of 0.30 eV. On contrary, the value of E{sub beff} was decreased from 0.21 eV to -0.03 eV due to the presence of high defect density at the GaAs{sub 0.35}Sb{sub 0.65}/In{sub 0.7}Ga{sub 0.3}As heterointerface. As a result, the band alignment was converted from staggered gap to broken gap, which leads to 4 orders of magnitude increase in OFF-state leakage current. Therefore, a high quality source/channel interface with a properly selected E{sub beff} and well maintained low defect density is necessary to obtain both high ON-state current and low OFF-state leakage in a mixed As/Sb TFET structure for high-performance and lower-power logic applications.},
doi = {10.1063/1.4764880},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 9,
volume = 112,
place = {United States},
year = {2012},
month = {11}
}