Wiring structure formed in contact hole, manufacturing method therefor, and a display apparatus having the same

摘要

A contact hole is formed, by etching that uses buffered hydrofluoric acid, in a gate insulating film made of SiO₂ and an interlayer insulating layer, formed on the gate insulating film, which is made of SiN. In this contact hole, there is formed an electrode which includes: a first protective metal layer made of a refractory metal; a wiring layer, formed on the first protective metal layer, which is made of a metal whose resistance is lower than that of the refractory metal; and a second protective metal layer, made of a refractory metal, which is formed thicker than the gate insulating film.