Electrical properties of 4H-SiC MIS capacitors with AlN gate dielectric grown by MOCVD
Journal article, 2019

We report on the electrical properties of the AlN/4H-SiC interface using capacitance- and conductance-voltage (CV and GV) analysis of AlN/SiC MIS capacitors. The crystalline AlN layers are made by hot wall MOCVD. CV analysis at room temperature reveals an order of magnitude lower density of interface traps at the AlN/SiC interface than at nitrided SiO2/SiC interfaces. Electron trapping in bulk traps within the AlN is significant when the MIS capacitors are biased into accumulation resulting in a large flatband voltage shift towards higher gate voltage. This process is reversible and the electrons are fully released from the AlN layer if depletion bias is applied at elevated temperatures. Current-voltage (IV) analysis reveals that the breakdown electric field intensity across the AlN dielectric is 3–4 MV/cm and is limited by trap assisted leakage. By depositing an additional SiO2 layer on top of the AlN layer, it is possible to increase the breakdown voltage of the MIS capacitors significantly without having much impact on the quality of the AlN/SiC interface.

MIS capacitors

Gate dielectrics

AlN/4H-SiC interface


Rabia Y. Khosa

University of Education Lahore

University of Iceland

J. T. Chen

Linköping University

K. Pálsson

University of Iceland

Robin Karhu

Linköping University

J. Hassan

Linköping University

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

E. O. Sveinbjornsson

University of Iceland

Linköping University

Solid-State Electronics

00381101 (ISSN)

Vol. 153 52-58

Subject Categories

Other Materials Engineering

Other Electrical Engineering, Electronic Engineering, Information Engineering

Condensed Matter Physics



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