Scandium-Based Ohmic Contacts to InAlN/GaN Heterostructures on Silicon

Charan, VS and Vura, S and Muralidharan, R and Raghavan, S and Nath, DN (2021) Scandium-Based Ohmic Contacts to InAlN/GaN Heterostructures on Silicon. In: IEEE Electron Device Letters, 42 (4). pp. 497-500.

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Abstract

We report a novel Sc/Al/Ni/Au metal scheme for Ohmic contacts to InAlN/GaN HEMT structures on silicon. A contact resistance of 0.39~\Omega -mm with a low surface roughness of 20± 3 nm of the annealed contact has been achieved using this metal scheme. The microstructure of the region under the contacts revealed the formation of 60 nm deep ScGaN inclusions in the GaN channel layer. A thin (3-5 nm) non-uniform layer of ScInAlN is observed on top of InAlN barrier. Field-emission is found to be the dominant conduction mechanism. Polarization mismatch arising due to the structural modifications is used to explain the possible mechanism related to Ohmic contact formation.

Item Type:	Journal Article
Publication:	IEEE Electron Device Letters
Publisher:	Institute of Electrical and Electronics Engineers Inc.
Additional Information:	The copyright for this article belongs to Institute of Electrical and Electronics Engineers Inc.
Keywords:	Electric contactors; Gallium nitride; III-V semiconductors; Indium compounds; Ohmic contacts; Scandium; Silicon; Surface roughness, Channel layers; Conduction Mechanism; InAlN/GaN HEMT; Low surface roughness; Non-uniform layer; Ohmic contact formation; Possible mechanisms; Structural modifications, Aluminum compounds
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	16 Feb 2023 10:32
Last Modified:	16 Feb 2023 10:32
URI:	https://eprints.iisc.ac.in/id/eprint/80518

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