Threshold voltage of excimer-laser-annealed polycrystalline silicon thin-film transistors

Based on experimental studies of n-channel excimer-laser-annealed polycryst alline silicon thin-film transistors with gate ratio width/length varying f rom 0.5 to 2.5, we propose a reliable method to determine the threshold vol tage V-t from linear extrapolation of the transconductance to zero. The res ults reveal that the determined values of V-t are independent of the device geometry and the applied drain voltage in the linear region, in contrast w ith the drain current linear extrapolation method. The values of V-t are co rrelated with the density of the total trap states derived from the subthre shold gate swing voltage. (C) 2000 American Institute of Physics. [S0003-69 51(00)01617-X].