The Effect of Charge Redistribution on Flat-Band Voltage Turnaround in 4H-SiC MOS Capacitors

Abstract:

The existence of a turnaround in flat-band voltage shift of stressed MOS capacitors, fabricated on N-type 4H–SiC substrates, is reported in this paper. The turnaround is observed by room-temperature C–V measurements, after two minutes gate-bias stressing of the MOS capacitors at different temperatures. The existence of this turnaround effect demonstrates that a mechanism, in addition to the well-stablished tunneling to the near-interface oxide traps, is involved in the threshold voltage instability of 4H–SiC MOSFETs. This newly identified mechanism occurs due to charge redistribution of the compound polar species that exist in the SiO₂–SiC transitional layer.

• Periodical: Materials Science Forum (Volume 897)
• Pages: 167-170
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.897.167
• Online since: May 2017
• Authors: Hamid Amini Moghadam*, Sima Dimitrijev, Ji Sheng Han, Daniel Haasmann
• Keywords: 4H-SiC, Capacitance-Voltage Shift, C-V Measurements, MOS Capacitor, Threshold Voltage Instability

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