Abstract
This investigation characterizes electrical characteristics of continuous-wave green laser-annealed single-grainlike silicon thin-film transistors in relation to trap-state densities. As laser power increases, highly crystalline channels form, reducing tail-state densities to as low as 3× 1019 eV-1 cm-3. This occurrence is responsible for high field-effect electron mobility of 284 cm2 V s. In contrast, increasing laser power initially reduces the deep-state density and then increases it to 3× 1016 eV-1 cm-3. This reversal in deep-state density and thus in the subthreshold slope as well as a saturating reduction in threshold voltage are associated with the formation of extra interface defects caused by laser-crystallization-enhanced surface roughness. © 2006 American Institute of Physics.