Analysis of Trapping Effects on the Forward Current-Voltage Characteristics of Al-Implanted 4H-SiC p-i-n Diodes

The forward current-voltage characteristics (I F -V F ) of aluminum (Al)-implanted 4H-SiC p-i-n diodes are investigated by means of a numerical simulation study that takes into account both intrinsic and doping-induced deep defects, namely, the Z 1/2 and EH 6/7 centers inside the drift region and an...

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Bibliographic Details
Published in:IEEE transactions on electron devices Vol. 65; no. 8; pp. 3371 - 3378
Main Authors: Megherbi, M. Larbi, Pezzimenti, Fortunato, Dehimi, Lakhdar, Saadoune, M. Achour, Della Corte, Francesco G.
Format: Journal Article
Language:English
Published: New York IEEE 01-08-2018
The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
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Summary:The forward current-voltage characteristics (I F -V F ) of aluminum (Al)-implanted 4H-SiC p-i-n diodes are investigated by means of a numerical simulation study that takes into account both intrinsic and doping-induced deep defects, namely, the Z 1/2 and EH 6/7 centers inside the drift region and an electrically active trap concentration inside the anode region due to the Al + ion implantation process. From the experimental results, the fundamental electric parameters of several samples were extracted at different regions of diode operation and used for comparison. The modeling analysis reveals that Z 1/2 and EH 6/7 centers reduce the effective carrier lifetimes and increase the recombination rate in the drift region determining the slope of the I F curve in the recombination and diffusion regimes. In addition, a defect density that becomes comparable to the epilayer doping concentration introduces an apparent shunt resistance effect at low-medium biases and at the same time has a noticeable impact on the diode series resistance at voltages higher than 2.7 V. A detrimental effect on the series resistance is also observed in dependence of the trap concentration in the anode region that increases the diode's internal resistance as a consequence of the carrier mobility decrease. Above the I F curve knee, the diode current is largely dominated by the electron injection into the anode since the concentration of free holes for conduction is strongly limited in turn by the incomplete activation of the ion-implanted impurities and the trap activity.
ISSN:0018-9383
1557-9646
DOI:10.1109/TED.2018.2849693