Charge trapping and storage in SiN_x thin films deposited with Oxford PlasmaLab 100 System

摘要

Negative charges in silicon nitride films are beneficial for surface passivation of rear side of p type solar cells.PI Previous studies indicates that N-rich SiN_x, films in an oxide-nit ride-oxide structure display good charge trapping and storage ability. In this work, an Oxford PlasmaLab 100 PECVD system is used to vary the deposition conditions (temperature and RF power). SiN_x films deposited at 400°C and RF=60W show an initial negative charge density of 1.2x10~(13)/cm~2 after negative charge injection. Modeling results suggest that tunnel oxide may not be necessary for achieving good charge stability, which will make the application more flexible.