Thin film transistor and active matrix liquid crystal display device having reduced photoelectric leakage current due to incident light

摘要

Leakage current due to light incident upon the semiconductor layer which forms the channel of a TFT is eliminated. An insulating layer is formed between one of source and drain electrodes and the semiconductor layer over a distance which is longer than a hole-electron recombination distance, from all the edges of at least one of the source and drain electrodes of the TFT so that it overlaps the semiconductor layer.