Comprehensive analysis of current leakage at individual screw and mixed threading dislocations in freestanding GaN substrates.
Journal
Scientific reports
ISSN: 2045-2322
Titre abrégé: Sci Rep
Pays: England
ID NLM: 101563288
Informations de publication
Date de publication:
10 Feb 2023
10 Feb 2023
Historique:
received:
04
12
2022
accepted:
06
02
2023
pubmed:
11
2
2023
medline:
11
2
2023
entrez:
10
2
2023
Statut:
epublish
Résumé
The electrical characteristics of Schottky contacts on individual threading dislocations (TDs) with a screw-component in GaN substrates and the structures of these TDs were investigated to assess the effects of such defects on reverse leakage currents. Micrometer-scale platinum/GaN Schottky contacts were selectively fabricated on screw- and mixed-TD-related etch pits classified based on the pit size. Current-voltage (I-V) data acquired using conductive atomic force microscopy showed that very few of the screw TDs generated anomalously large reverse leakage currents. An analysis of the temperature dependence of the I-V characteristics established that the leakage current conduction mechanisms for the leaky screw TDs differed from those for the other screw and mixed TDs. Specifically, anomalous current leakage was generated by Poole-Frenkel emission and trap-assisted tunneling via distinctive trap states together with Fowler-Nordheim tunneling, with the mechanism changing according to variations in temperature and applied voltage. The leaky TDs were identified as Burgers vector b = 1c closed-core screw TDs having a helical morphology similar to that of other screw TDs generating small leakage currents. Based on the results, we proposed that the atomic-scale modification of the dislocation core structure related to interactions with point defects via dislocation climbing caused different leakage characteristics of the TDs.
Identifiants
pubmed: 36765088
doi: 10.1038/s41598-023-29458-3
pii: 10.1038/s41598-023-29458-3
pmc: PMC9918472
doi:
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
2436Subventions
Organisme : Japan Science and Technology Agency
ID : J121052565
Organisme : KAKENHI Grant-in-Aid
ID : JP16H06423
Informations de copyright
© 2023. The Author(s).
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