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Proceedings Paper

Investigation of interfacial impurities in m-plane GaN regrown p-n junctions for high-power vertical electronic devices
Author(s): Isaac Stricklin; Morteza Monavarian; Andrew Aragon; Greg Pickrell; Mary Crawford; Andrew Allerman; Andrew Armstrong; Daniel Feezell
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Paper Abstract

GaN is an attractive material for high-power electronics due to its wide bandgap and large breakdown field. Verticalgeometry devices are of interest due to their high blocking voltage and small form factor. One challenge for realizing complex vertical devices is the regrowth of low-leakage-current p-n junctions within selectively defined regions of the wafer. Presently, regrown p-n junctions exhibit higher leakage current than continuously grown p-n junctions, possibly due to impurity incorporation at the regrowth interfaces, which consist of c-plane and non-basal planes. Here, we study the interfacial impurity incorporation induced by various growth interruptions and regrowth conditions on m-plane p-n junctions on free-standing GaN substrates. The following interruption types were investigated: (1) sample in the main MOCVD chamber for 10 min, (2) sample in the MOCVD load lock for 10 min, (3) sample outside the MOCVD for 10 min, and (4) sample outside the MOCVD for one week. Regrowth after the interruptions was performed on two different samples under n-GaN and p-GaN growth conditions, respectively. Secondary ion mass spectrometry (SIMS) analysis indicated interfacial silicon spikes with concentrations ranging from 5e16 cm-3 to 2e18 cm-3 for the n-GaN growth conditions and 2e16 cm-3 to 5e18 cm-3 for the p-GaN growth conditions. Oxygen spikes with concentrations ~1e17 cm-3 were observed at the regrowth interfaces. Carbon impurity levels did not spike at the regrowth interfaces under either set of growth conditions. We have correlated the effects of these interfacial impurities with the reverse leakage current and breakdown voltage of regrown m-plane p-n junctions.

Paper Details

Date Published: 7 September 2018
PDF: 10 pages
Proc. SPIE 10754, Wide Bandgap Power and Energy Devices and Applications III, 1075402 (7 September 2018); doi: 10.1117/12.2322005
Show Author Affiliations
Isaac Stricklin, The Univ. of New Mexico (United States)
Morteza Monavarian, The Univ. of New Mexico (United States)
Andrew Aragon, The Univ. of New Mexico (United States)
Greg Pickrell, Sandia National Labs. (United States)
Mary Crawford, Sandia National Labs. (United States)
Andrew Allerman, Sandia National Labs. (United States)
Andrew Armstrong, Sandia National Labs. (United States)
Daniel Feezell, The Univ. of New Mexico (United States)

Published in SPIE Proceedings Vol. 10754:
Wide Bandgap Power and Energy Devices and Applications III
Mohammad Matin; Srabanti Chowdhury; Achyut K. Dutta, Editor(s)

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