Improved performance in vertical GaN Schottky diode assisted by AlGaN tunneling barrier

Y. Cao, Rongming Chu, R. Li, M. Chen, A. J. Williams

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

In a vertical GaN Schottky barrier diode, the free electron concentration n in the 6-μm-thick drift layer was found to greatly impact the diode reverse leakage current, which increased from 2.1 × 10-7 A to 3.9 × 10-4 A as n increased from 7.5 × 1014cm-3 to 6.3 × 1015cm-3 at a reverse bias of 100 V. By capping the drift layer with an ultrathin 5-nm graded AlGaN layer, reverse leakage was reduced by more than three orders of magnitude with the same n in the drift layer. We attribute this to the increased Schottky barrier height with the AlGaN at the surface. Meanwhile, the polarization field within the graded AlGaN effectively shortened the depletion depth, which led to the formation of tunneling current at a relatively small forward bias. The turn-on voltage in the vertical Schottky diodes was reduced from 0.77 V to 0.67 V - an advantage in reducing conduction loss in power switching applications.

Original languageEnglish (US)
Article number112101
JournalApplied Physics Letters
Volume108
Issue number11
DOIs
StatePublished - Mar 14 2016

Fingerprint

Schottky diodes
leakage
free electrons
depletion
diodes
conduction
electric potential
polarization

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this

@article{fb8a38c620ef4ec98c93a1cb3f73ba27,
title = "Improved performance in vertical GaN Schottky diode assisted by AlGaN tunneling barrier",
abstract = "In a vertical GaN Schottky barrier diode, the free electron concentration n in the 6-μm-thick drift layer was found to greatly impact the diode reverse leakage current, which increased from 2.1 × 10-7 A to 3.9 × 10-4 A as n increased from 7.5 × 1014cm-3 to 6.3 × 1015cm-3 at a reverse bias of 100 V. By capping the drift layer with an ultrathin 5-nm graded AlGaN layer, reverse leakage was reduced by more than three orders of magnitude with the same n in the drift layer. We attribute this to the increased Schottky barrier height with the AlGaN at the surface. Meanwhile, the polarization field within the graded AlGaN effectively shortened the depletion depth, which led to the formation of tunneling current at a relatively small forward bias. The turn-on voltage in the vertical Schottky diodes was reduced from 0.77 V to 0.67 V - an advantage in reducing conduction loss in power switching applications.",
author = "Y. Cao and Rongming Chu and R. Li and M. Chen and Williams, {A. J.}",
year = "2016",
month = "3",
day = "14",
doi = "10.1063/1.4943946",
language = "English (US)",
volume = "108",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "11",

}

Improved performance in vertical GaN Schottky diode assisted by AlGaN tunneling barrier. / Cao, Y.; Chu, Rongming; Li, R.; Chen, M.; Williams, A. J.

In: Applied Physics Letters, Vol. 108, No. 11, 112101, 14.03.2016.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Improved performance in vertical GaN Schottky diode assisted by AlGaN tunneling barrier

AU - Cao, Y.

AU - Chu, Rongming

AU - Li, R.

AU - Chen, M.

AU - Williams, A. J.

PY - 2016/3/14

Y1 - 2016/3/14

N2 - In a vertical GaN Schottky barrier diode, the free electron concentration n in the 6-μm-thick drift layer was found to greatly impact the diode reverse leakage current, which increased from 2.1 × 10-7 A to 3.9 × 10-4 A as n increased from 7.5 × 1014cm-3 to 6.3 × 1015cm-3 at a reverse bias of 100 V. By capping the drift layer with an ultrathin 5-nm graded AlGaN layer, reverse leakage was reduced by more than three orders of magnitude with the same n in the drift layer. We attribute this to the increased Schottky barrier height with the AlGaN at the surface. Meanwhile, the polarization field within the graded AlGaN effectively shortened the depletion depth, which led to the formation of tunneling current at a relatively small forward bias. The turn-on voltage in the vertical Schottky diodes was reduced from 0.77 V to 0.67 V - an advantage in reducing conduction loss in power switching applications.

AB - In a vertical GaN Schottky barrier diode, the free electron concentration n in the 6-μm-thick drift layer was found to greatly impact the diode reverse leakage current, which increased from 2.1 × 10-7 A to 3.9 × 10-4 A as n increased from 7.5 × 1014cm-3 to 6.3 × 1015cm-3 at a reverse bias of 100 V. By capping the drift layer with an ultrathin 5-nm graded AlGaN layer, reverse leakage was reduced by more than three orders of magnitude with the same n in the drift layer. We attribute this to the increased Schottky barrier height with the AlGaN at the surface. Meanwhile, the polarization field within the graded AlGaN effectively shortened the depletion depth, which led to the formation of tunneling current at a relatively small forward bias. The turn-on voltage in the vertical Schottky diodes was reduced from 0.77 V to 0.67 V - an advantage in reducing conduction loss in power switching applications.

UR - http://www.scopus.com/inward/record.url?scp=84962590762&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84962590762&partnerID=8YFLogxK

U2 - 10.1063/1.4943946

DO - 10.1063/1.4943946

M3 - Article

VL - 108

JO - Applied Physics Letters

JF - Applied Physics Letters

SN - 0003-6951

IS - 11

M1 - 112101

ER -