Off-State Leakage And Current Collapse In Algan/Gan Hemts: A Virtual Gate Induced By Dislocations

Keywords

AlGaN/GaN high-electron-mobility transistors (HEMTs); current collapse; dislocations; gate leakage; trapping mechanism; virtual gate

Abstract

The existence of a correlation between current collapse and off-state reverse-bias leakage current in heteroepitaxially grown AlGaN/GaN high-electron-mobility transistors is investigated from the perspective of conductive threading dislocations. Collapsed current response (recoverable) to synchronized gate-drain voltage pulses is found to be governed by the epilayer's dislocation density, and also by the off-state quiescent bias scheme. Furthermore, magnitudes of reverse-gate leakages apart from being dislocation density dependent are found to have distinctive temperature-bias characteristics. Based on the trapping spatiality along with field and temperature dependence of the respective leakage currents; an emission mechanism is postulated involving donor-like surface states and dislocation induced deep levels. It is inferred that dislocations can indeed be responsible for the current collapse that has been long assumed to be caused by the surface states.

Publication Date

4-1-2018

Publication Title

IEEE Transactions on Electron Devices

Volume

65

Issue

4

Number of Pages

1333-1339

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1109/TED.2018.2808334

Socpus ID

85042857001 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85042857001

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