US Patent 7323717 Semiconductor device

A wiring line to which a high-frequency signal is applied is electrically connected in parallel to an auxiliary, wiring line via a plurality of contact holes. The contact holes are formed through an interlayer insulating film and arranged in vertical direction to the wiring line. Since the auxiliary wiring line is formed in the same layer as an electrode that constitutes a TFT, the electric resistance of the wiring line can be reduced effectively and waveform rounding of an applied high-frequency signal can be reduced without increasing the number of manufacturing steps.