Determination of electronic band structure by electron holography of etched-and-regrown interfaces in GaN p-i-n diodes

Shanthan R. Alugubelli, Houqiang Fu, Kai Fu, Hanxiao Liu, Yuji Zhao, Martha R. McCartney, Fernando A. Ponce

Research output: Contribution to journalArticle

Abstract

The electrostatic potential variation across etched-and-regrown GaN p-i-n diodes for power electronics has been studied using electron holography in a transmission electron microscope. The potential profiles have been correlated with the composition profiles of Mg, Si, and O obtained by secondary ion mass spectroscopy. Electronic charges obtained from the potential profiles correlate well with the presence of Si and O impurities at regrown interfaces. The overlap of Mg and Si when Mg doped GaN is grown directly over an etched undoped GaN surface results in the formation of a highly doped p-n junction. The introduction of a thin undoped layer over the etched GaN surface prevents the formation of such a junction as the regrowth interface is moved away from the Mg-doped GaN, and results in diodes with improved reverse leakage currents, close to the best values of continuously grown p-i-n diodes. Potential profiles of continuously grown (not etched) p-i-n diodes are compared to those of etched-and-regrown diodes.

Original languageEnglish (US)
Article number201602
JournalApplied Physics Letters
Volume115
Issue number20
DOIs
StatePublished - Nov 11 2019
Externally publishedYes

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p-i-n diodes
holography
profiles
electronics
electrons
diodes
p-n junctions
leakage
mass spectroscopy
electron microscopes
electrostatics
impurities
ions

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Determination of electronic band structure by electron holography of etched-and-regrown interfaces in GaN p-i-n diodes. / Alugubelli, Shanthan R.; Fu, Houqiang; Fu, Kai; Liu, Hanxiao; Zhao, Yuji; McCartney, Martha R.; Ponce, Fernando A.

In: Applied Physics Letters, Vol. 115, No. 20, 201602, 11.11.2019.

Research output: Contribution to journalArticle

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AU - McCartney, Martha R.

AU - Ponce, Fernando A.

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