Evolution of defect photoiuminescence in annealed N-rich a-SiN_x:H films

摘要

The N-rich a-SiN_x:H films were deposited on Si substrates by very high frequency plasma enhanced chemical vapor deposition technique at a low temperature of 250 °C. Strong blue photoiuminescence (PL), which originates from nitrogen dangling bond, can be observed in the as-deposited samples. The dependence of defect PL on annealing temperature was systematically investigated. The PL spectra reveal that the PL peak is almost independent of the annealing temperatures while the luminescence intensity rapidly decreases with the annealing temperature increasing from 400°C to 600°C. However, higher annealing temperatures over 700 °C results in an enhancement of luminescence intensity. Based on the relationship between PL spectra and bonding configurations of the samples, the evolution of defect PL with annealing temperatures was briefly discussed.