Poly-Si TFT fabricated by laser-induced in-situ fluorine passivation and laser doping

A new poly-Si TFT has been fabricated by employing laser-induced in-situ fluorine passivation and laser-doping method. With only one excimer laser annealing, we have successfully fabricated the device using one step to crystallize, passivate and dope simultaneously. Although any additional plasma post-passivation was not performed, the on-state and the off-state leakage properties of TFTs with fluorine passivation were improved compared with those without fluorine passivation. The device with in-situ fluorine passivation has the maximum transconductance of 13.3 muA/V for a C2F6 flow rate of 100 seem, while the device without fluorine passivation has that of 8.4 muA/V, The device reliability under electrical stress was remarkably improved in the in-situ fluorine-passivated devices due to the fluorine passivation effects of trap states in the poly-Si channel and SiO2/poly-Si interface.