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.