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Title: Indium Tin Oxide (ITO) based Ohmic Contacts on Bulk n-GaN Substrate

A transparent indium tin oxide (ITO) contact to bulk n-GaN and n-GaN thin film on c-face sapphire with a specific contact resistivity of 8.06 × 10−4Ω.cm2and 3.71 × 10−4Ω.cm2was measured, respectively. Our studies relied on an RF sputtering system for ITO deposition. We have investigated the formation of the ITO-based contacts on untreated and plasma treated samples. A nonlinearI–Vcurve was observed for ITO deposited on untreated samples. On the other hand, anI–Vcurve with linear behavior was observed for plasma-treated samples, indicating the formation of ohmic contacts. From theC-Vmeasurements, it was observed that there was also an increase in the carrier concentration in plasma treated samples compared to untreated samples. This can be attributed to the removal of surface oxide layer present on the GaN surface, and increase in nitrogen vacancies after SiCl4plasma treatment. In addition, the increase in nitrogen vacancies at the GaN surface can also enhance localized surface/sub-surface carriers, thereby reducing the contact resistance further.

 
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NSF-PAR ID:
10382571
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Publisher / Repository:
The Electrochemical Society
Date Published:
Journal Name:
ECS Journal of Solid State Science and Technology
Volume:
11
Issue:
11
ISSN:
2162-8769
Page Range / eLocation ID:
Article No. 115008
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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