Patent ID: 8558241

Claim:
An EL display device comprising a pixel, the pixel comprising: a thin film transistor comprising: a first semiconductor layer portion comprising a channel formation region, a first terminal region, and a second terminal region; a first insulating layer over the first semiconductor layer portion; a gate electrode layer overlapping the first semiconductor layer portion and over the first insulating layer; and a second insulating layer over the thin film transistor; a wiring and a current supply line made from a same film formed over the second insulating layer, the wiring being in electrical contact with one of the first terminal region and the second terminal region and the current supply line with the other of the first terminal region and the second terminal region; a third insulating layer over the wiring and the current supply line; a first electrode over the third insulating layer, the first electrode being in electrical contact with the wiring; an EL layer over the first electrode; a second electrode over the EL layer; and a capacitor overlapping with the current supply line, the capacitor comprising: a second semiconductor layer portion; a portion of the first insulating layer formed over the second semiconductor layer portion; and a third electrode formed over the first insulating layer from a same film as the gate electrode layer, and overlapping the second semiconductor layer portion, wherein a portion of the second insulating layer overlaps the third electrode and the second semiconductor layer portion.