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Three-Dimensional Imaging of Beam-Induced Biasing of InP/GaInP Tunnel Diodes

Cordoba, Cristina; Zeng, Xulu LU ; Wolf, Daniel; Lubk, Axel; Barrigón, Enrique LU ; Borgström, Magnus T. LU and Kavanagh, Karen L. (2019) In Nano Letters p.3490-3497
Abstract
Electron holographic tomography was used to obtain three-dimensional reconstructions of the morphology and electrostatic potential gradient of axial GaInP/InP nanowire tunnel diodes. Crystal growth was carried out in two opposite directions: GaInP–Zn/InP–S and InP–Sn/GaInP–Zn, using Zn as the p-type dopant in the GaInP but with changes to the n-type dopant (S or Sn) in the InP. Secondary electron and electron beam-induced current images obtained using scanning electron microscopy indicated the presence of p–n junctions in both cases and current–voltage characteristics measured via lithographic contacts showed the negative differential resistance, characteristic of band-to-band tunneling, for both diodes. Electron holographic tomography... (More)
Electron holographic tomography was used to obtain three-dimensional reconstructions of the morphology and electrostatic potential gradient of axial GaInP/InP nanowire tunnel diodes. Crystal growth was carried out in two opposite directions: GaInP–Zn/InP–S and InP–Sn/GaInP–Zn, using Zn as the p-type dopant in the GaInP but with changes to the n-type dopant (S or Sn) in the InP. Secondary electron and electron beam-induced current images obtained using scanning electron microscopy indicated the presence of p–n junctions in both cases and current–voltage characteristics measured via lithographic contacts showed the negative differential resistance, characteristic of band-to-band tunneling, for both diodes. Electron holographic tomography measurements confirmed a short depletion width in both cases (21 ± 3 nm) but different built-in potentials, Vbi, of 1.0 V for the p-type (Zn) to n-type (S) transition, and 0.4 V for both were lower than the expected 1.5 V for these junctions if degenerately doped. Charging induced by the electron beam was evident in phase images which showed nonlinearity in the surrounding vacuum, most severe in the case of the nanowire grounded at the p-type Au contact. We attribute their lower Vbi to asymmetric secondary electron emission, beam-induced current biasing, and poor grounding contacts. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
in
Nano Letters
pages
3490 - 3497
publisher
The American Chemical Society
external identifiers
  • scopus:85066132805
ISSN
1530-6984
DOI
10.1021/acs.nanolett.9b00249
language
English
LU publication?
yes
id
f020315a-6066-4068-a5a2-7d08800015d3
date added to LUP
2019-05-15 11:52:03
date last changed
2019-07-02 04:45:01
@article{f020315a-6066-4068-a5a2-7d08800015d3,
  abstract     = {Electron holographic tomography was used to obtain three-dimensional reconstructions of the morphology and electrostatic potential gradient of axial GaInP/InP nanowire tunnel diodes. Crystal growth was carried out in two opposite directions: GaInP–Zn/InP–S and InP–Sn/GaInP–Zn, using Zn as the p-type dopant in the GaInP but with changes to the n-type dopant (S or Sn) in the InP. Secondary electron and electron beam-induced current images obtained using scanning electron microscopy indicated the presence of p–n junctions in both cases and current–voltage characteristics measured via lithographic contacts showed the negative differential resistance, characteristic of band-to-band tunneling, for both diodes. Electron holographic tomography measurements confirmed a short depletion width in both cases (21 ± 3 nm) but different built-in potentials, Vbi, of 1.0 V for the p-type (Zn) to n-type (S) transition, and 0.4 V for both were lower than the expected 1.5 V for these junctions if degenerately doped. Charging induced by the electron beam was evident in phase images which showed nonlinearity in the surrounding vacuum, most severe in the case of the nanowire grounded at the p-type Au contact. We attribute their lower Vbi to asymmetric secondary electron emission, beam-induced current biasing, and poor grounding contacts.},
  author       = {Cordoba, Cristina and Zeng, Xulu and Wolf, Daniel and Lubk, Axel and Barrigón, Enrique and Borgström, Magnus T. and Kavanagh, Karen L.},
  issn         = {1530-6984},
  language     = {eng},
  pages        = {3490--3497},
  publisher    = {The American Chemical Society},
  series       = {Nano Letters},
  title        = {Three-Dimensional Imaging of Beam-Induced Biasing of InP/GaInP Tunnel Diodes},
  url          = {http://dx.doi.org/10.1021/acs.nanolett.9b00249},
  year         = {2019},
}