Patent attributes
It is an object of the present invention to provide a semiconductor display device using a protective circuit in which dielectric breakdown is prevented more effectively. In the invention, in the cases that a first interlayer insulating film is formed covering a TFT used for a protective circuit and a second interlayer insulating film, which is an insulating coating film, is formed covering a wiring formed over the first interlayer insulating film, a wiring for connecting the TFT to other semiconductor elements is formed so as to be in contact with the surface of the second interlayer insulating film so as to secure a path discharging charge accumulated in the surface of the second interlayer insulating film. Note that the TFT used for the protective diode is a so-called diode-connected TFT in which either of the first terminal or the second terminal is connected to a gate electrode.
