Influence of TCE concentration in thermal oxidation on reliability of SiC MOS capacitors under Fowler–Nordheim electron injection

The effects of trichloroethylene (TCE) concentration in SiC thermal oxidation on the reliability of MOS capacitors under Fowler–Nordheim (FN) electron injection have been investigated. It is found that TCE thermal oxidation can enhance the resistance of the SiO2/SiC interface against generation of interface states and oxide charges caused by FN electron injection, and the resistance increases with TCE ratio increasing from 0 to 0.1. As compared with the control sample based on dry-O2 oxidation, the interface-state generation at 0.25 eV below the conduction-band edge is 5, 23, and 170 times smaller for samples with TCE ratio of 0.01, 0.05 and 0.1 respectively. In addition, the interface traps and oxide-charge traps of fresh samples decrease with increasing TCE ratio for the ratio less than 0.01, and then increase for larger ratio. It is proposed that the enhanced resistance against the stress is attributed to the gettering or dislodging of electrical and physical defects by the chlorine atoms incorporated in the oxide during the TCE oxidation.