Modified Interface Properties of Au/n-type GaN Schottky Junction with a High-k Ba0.6Sr0.4TiO3 Insulating Layer

Reddy, Varra Niteesh and Gunasekhar, KR (2018) Modified Interface Properties of Au/n-type GaN Schottky Junction with a High-k Ba0.6Sr0.4TiO3 Insulating Layer. In: JOURNAL OF ELECTRONIC MATERIALS, 47 (11). pp. 6458-6466.

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Abstract

The interface properties of a Au/n-GaN Schottky junction (SJ) were modified by placing a high-k barium strontium titanate (Ba0.6Sr0.4TiO3) insulating layer between the Au and n-GaN semiconductor. The surface morphology, chemical composition, and electrical properties of Au/Ba0.6Sr0.4TiO3 (BST)/n-GaN metal/insulator/semiconductor (MIS) junctions were explored by atomic force microscopy, energy-dispersive x-ray spectroscopy, current-voltage (I-V) and capacitance-voltage (C-V) techniques. The electrical results of the MIS junction are correlated with the SJ and discussed further. The MIS junction exhibited an exquisite rectifying nature compared to the SJ. An average barrier height (BH) and ideality factors were extracted to be 0.77eV, 1.62eV and 0.92eV, 1.95 for the SJ and MIS junction, respectively. The barrier was raised by 150meV for the MIS junction compared to the MS junction, implying that the BH was effectively altered by the BST insulating layer. The BH values extracted by I-V, Cheung's and Norde functions were nearly equal to one another, indicating that the techniques applied here were dependable and suitable. The frequency-dependent properties of the SJ and MIS junction were explored and discussed. It was found that the interface state density of the MIS junction was smaller than the SJ. This implies that the BST layer plays an imperative role in the decreased N-SS. Poole-Frenkel emission was the prevailed current conduction mechanism in the reverse-bias of both the SJ and MIS junction.

Item Type:	Journal Article
Publication:	JOURNAL OF ELECTRONIC MATERIALS
Publisher:	SPRINGER
Additional Information:	Copy right for this article belong to SPRINGER
Keywords:	n-type GaN; high-k Ba0; 6Sr0; 4TiO(3); insulating layer; metal; insulator; semiconductor; electrical properties; interface state density; carrier transport properties
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	15 Oct 2018 15:24
Last Modified:	15 Oct 2018 15:24
URI:	http://eprints.iisc.ac.in/id/eprint/60872

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