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

Title: Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN]

Abstract

Here, inherent advantages of wide bandgap materials make GaN-based devices attractive for power electronics and applications in radiation environments. Recent advances in the availability of wafer-scale, bulk GaN substrates have enabled the production of high quality, low defect density GaN devices, but fundamental studies of carrier transport and radiation hardness in such devices are lacking. Here, we report measurements of the hole diffusion length in low threading dislocation density (TDD), homoepitaxial n-GaN, and high TDD heteroepitaxial n-GaN Schottky diodes before and after irradiation with 2.5 MeV protons at fluences of 4–6 × 10 13 protons/cm 2. We also characterize the specimens before and after irradiation using electron beam-induced-current (EBIC) imaging, cathodoluminescence, deep level optical spectroscopy (DLOS), steady-state photocapacitance, and lighted capacitance-voltage (LCV) techniques. We observe a substantial reduction in the hole diffusion length following irradiation (50%–55%) and the introduction of electrically active defects which could be attributed to gallium vacancies and associated complexes (V Ga-related), carbon impurities (C-related), and gallium interstitials (Ga i). EBIC imaging suggests long-range migration and clustering of radiation-induced point defects over distances of ~500 nm, which suggests mobile Ga i. Following irradiation, DLOS and LCV reveal the introduction of a prominent optical energy level at 1.9more » eV below the conduction band edge, consistent with the introduction of Ga i.« less

Authors:
 [1];  [2];  [2];  [2];  [2];  [1];  [1]
  1. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1421641
Alternate Identifier(s):
OSTI ID: 1414507
Report Number(s):
SAND-2017-13818J
Journal ID: ISSN 0021-8979; 659684
Grant/Contract Number:
AC04-94AL85000
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 122; Journal Issue: 23; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Collins, K. C., Armstrong, Andrew M., Allerman, Andrew A., Vizkelethy, G., Van Deusen, Stuart B., Leonard, Francois, and Talin, Albert Alec. Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN]. United States: N. p., 2017. Web. doi:10.1063/1.5006814.
Collins, K. C., Armstrong, Andrew M., Allerman, Andrew A., Vizkelethy, G., Van Deusen, Stuart B., Leonard, Francois, & Talin, Albert Alec. Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN]. United States. doi:10.1063/1.5006814.
Collins, K. C., Armstrong, Andrew M., Allerman, Andrew A., Vizkelethy, G., Van Deusen, Stuart B., Leonard, Francois, and Talin, Albert Alec. Thu . "Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN]". United States. doi:10.1063/1.5006814.
@article{osti_1421641,
title = {Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN]},
author = {Collins, K. C. and Armstrong, Andrew M. and Allerman, Andrew A. and Vizkelethy, G. and Van Deusen, Stuart B. and Leonard, Francois and Talin, Albert Alec},
abstractNote = {Here, inherent advantages of wide bandgap materials make GaN-based devices attractive for power electronics and applications in radiation environments. Recent advances in the availability of wafer-scale, bulk GaN substrates have enabled the production of high quality, low defect density GaN devices, but fundamental studies of carrier transport and radiation hardness in such devices are lacking. Here, we report measurements of the hole diffusion length in low threading dislocation density (TDD), homoepitaxial n-GaN, and high TDD heteroepitaxial n-GaN Schottky diodes before and after irradiation with 2.5 MeV protons at fluences of 4–6 × 1013 protons/cm2. We also characterize the specimens before and after irradiation using electron beam-induced-current (EBIC) imaging, cathodoluminescence, deep level optical spectroscopy (DLOS), steady-state photocapacitance, and lighted capacitance-voltage (LCV) techniques. We observe a substantial reduction in the hole diffusion length following irradiation (50%–55%) and the introduction of electrically active defects which could be attributed to gallium vacancies and associated complexes (VGa-related), carbon impurities (C-related), and gallium interstitials (Gai). EBIC imaging suggests long-range migration and clustering of radiation-induced point defects over distances of ~500 nm, which suggests mobile Gai. Following irradiation, DLOS and LCV reveal the introduction of a prominent optical energy level at 1.9 eV below the conduction band edge, consistent with the introduction of Gai.},
doi = {10.1063/1.5006814},
journal = {Journal of Applied Physics},
number = 23,
volume = 122,
place = {United States},
year = {Thu Dec 21 00:00:00 EST 2017},
month = {Thu Dec 21 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on December 21, 2018
Publisher's Version of Record

Save / Share: