THIN-FILM TRANSISTOR SUBSTRATE AND DISPLAY DEVICE COMPRISING THE SAME

A thin-film transistor substrate and a display device comprising the same are provided which can improve display quality by reducing or preventing deterioration of the characteristics of thin-film transistors. The thin-film transistor substrate comprises thin-film transistors on a lower protective metal layer (114). Each thin-film transistor comprises a buffer layer (116), a semiconductor layer (120), a first insulating film (125), a gate electrode (130), a second insulating film (135), a source electrode (140) and a drain electrode (145), and a first electrode. The lower protective metal layer (114) is electrically connected to the gate electrode (130) and overlaps the channel region (CH) of the semiconductor layer (120).