Improved Uniformity of Sequential Lateral Solidification Thin-Film Transistors

The uniformity of threshold voltage (V
_th
) in sequential lateral solidification (SLS) thin-film transistors (TFTs) is investigated. Some SLS TFTs have higher V
_th
values than others, which causes problems in applications requiring a high level of TFT uniformity such as active-matrix organic light-emitting diode displays. Focused ion beam observations revealed that all TFTs with high V
_th
values had protrusions 3000- 7000 Å from the junction. Using a smart tilted-channel structure decreased the V
_th
variation to less than 0.2 V.