HIGH-FIELD FOWLER-NORDHEIM STRESS OF N-TYPE SILICON-CARBIDE METAL-OXIDE-SEMICONDUCTOR CAPACITORS

Fowler-Nordheim electron injections have been carried out in n-type si licon carbide (SiC) metal-oxide-semiconductor (MOS) capacitors. A syst ematic variation in the temperature and in the average oxide field E-o x applied during the stress allowed us to show both a positive charge and electron trapping. The positive charge build-up is shown to emerge above a critical oxide field close to 7 MV cm(-1). It decreases with temperature, and can be dissociated into two different exponential tim e processes. The overall results agree with mechanisms based on impact ionization in the oxide, leading to pair creation and subsequent hole trapping.