A thin-film transistor array substrate is disclosed. In one embodiment, the transistor includes a capacitor including a lower electrode disposed on the same layer as an active layer and an upper electrode disposed on the same layer as a gate electrode. The transistor may also include a first insulating layer disposed between the active layer and the gate electrode and between the lower and upper electrodes, the first insulating layer not being disposed on a perimeter of the lower electrode. The transistor may further include a second insulating layer between the first insulating layer and the source and drain electrodes, the second insulating layer not being disposed on perimeters of the upper and lower electrodes.