Resistivity contrast imaging in semiconductor structures using ultra-low energy scanning electron microscopy

Iwona Jóźwik; Jacek Jagielski; Ewa Dumiszewska; Maciej Kamiński; Ulrich Kentsch

doi:10.1016/j.ultramic.2021.113333

Resistivity contrast imaging in semiconductor structures using ultra-low energy scanning electron microscopy

Ultramicroscopy. 2021 Sep:228:113333. doi: 10.1016/j.ultramic.2021.113333. Epub 2021 May 30.

Authors

Iwona Jóźwik¹, Jacek Jagielski², Ewa Dumiszewska³, Maciej Kamiński⁴, Ulrich Kentsch⁵

Affiliations

¹ Lukasiewicz Research Network - Institute of Microelectronics and Photonics, Lotników Av. 32/46, Warsaw, Poland; NOMATEN Centre of Excellence, NOMATEN MAB, National Centre for Nuclear Research, 7th A. Soltana Str., Świerk-Otwock, Poland. Electronic address: iwona.jozwik@imif.lukasiewicz.gov.pl.
² Lukasiewicz Research Network - Institute of Microelectronics and Photonics, Lotników Av. 32/46, Warsaw, Poland; Material Physics Department, National Centre for Nuclear Research, 7th A. Soltana Str., Świerk-Otwock, Poland.
³ Lukasiewicz Research Network - Institute of Microelectronics and Photonics, Lotników Av. 32/46, Warsaw, Poland.
⁴ Lukasiewicz Research Network - Institute of Microelectronics and Photonics, Lotników Av. 32/46, Warsaw, Poland; Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Pl. Politechniki 1, 00-661, Warsaw, Poland.
⁵ Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf e.V. (HZDR), D-01328, Dresden, Germany.

PMID: 34134066
DOI: 10.1016/j.ultramic.2021.113333

Abstract

The damage-induced voltage alteration (DIVA) contrast mechanism in scanning electron microscope (SEM) has been studied in broad range of the primary electron beam energies, with a special emphasis on the ultra-low energy range. The SEM imaging contrast related to resistivity changes in the In_(0.55)Al_(0.45)P irradiated with He²⁺ ions of 600 keV was subjected to an analysis in a range of 10 keV down to 10 eV of primary electron energies. The problem of specimen charging in ultra-low energy range and its effect on the contrast in SEM images has been tackled for the first time. Contrary to expectations based on the classical total emission yield approach, the potentials formed at the highly resistive part of irradiated area led to dramatic increase in the intensity of registered signal for primary electron energies below E₁, which can be explained as signal saturation due to potential on the specimen surface acting as repeller for primary electrons. Nevertheless, the experimental data presenting the influence of the beam energy on the potential formation on the surface of an insulating material under electron irradiation have been presented for the first time in ultra-low energy regime.

Keywords: Ion damage; Ion irradiation; Low-kV SEM; Semiconductors.