Performance and reliability of SLS ELA polysilicon TFTs fabricated with novel crystallization techniques

SLS ELA polysilicon TFTs fabricated in films crystallized with several novel techniques, yielding different film microstructure and texture, were investigated. The parameter statistics indicate that the TFT performance depends on film quality and asperities, in conjunction with the grain boundary trap density. The drain current transients, upon TFT switch from OFF to ON state, showed gate oxide polarization, related to film asperities and also confirmed the presence of extended defects in the TFTs of small mobilities. DC hot carrier stress was applied, indicating a reliability dependence on polysilicon structure and differences in degradation mechanisms for the various TFT technologies.