Hydrogen interaction with defects and impurities in 6H-SiC

The dynamics of hydrogen capture and release from trapping centers in 6H-SiC after plasma hydrogenation and annealing was investigated by low-temperature photoluminescence (PL). Indications of competing processes of hydrogen capture by different trapping centers were observed. Passivation of Al acceptors with hydrogen is the dominating process during plasma hydrogenation or plasma etching. Irreversible release of hydrogen from Al-trapping centers and additional trapping of hydrogen by Si vacancy (VSi) to form a VSi+H complex occurred during annealing at temperatures above 300°C. It is suggested that the VSi+H complex may be playing an important role in keeping hydrogen in SiC after higher temperature treatment.