Patent ID: 7270759

Claim:
A method of producing a liquid discharge head comprising a semiconductor substrate, a silicon oxide film and a silicon nitride film, wherein the silicon oxide film and the silicon nitride film are disposed on a first principal surface of the semiconductor substrate, and a through hole is formed to penetrate the semiconductor substrate, the silicon oxide film, and the silicon nitride film, said method comprising: forming a sacrificial layer on the first principal surface of the semiconductor substrate, at a position corresponding to a forming position of the through hole; forming the silicon oxide film so as to cover the sacrificial layer and the whole of the first principal surface of the semiconductor substrate; forming the silicon nitride film on the silicon oxide film; and thereafter, etching the semiconductor substrate from a second principal surface side of the semiconductor substrate so as to remove the sacrificial layer, and etching the silicon oxide film and the silicon nitride film so as to form the through hole.