Provided are a liquid-jet head in which a passage-forming substrate and a nozzle plate can be suitably joined, a method of manufacturing the same, and a liquid-jet apparatus. A covering plate has a piezoelectric element holding portion which covers piezoelectric elements. This covering plate is joined with a side of the passage-forming substrate where the piezoelectric elements are provided. At the same time, the nozzle plate provided with nozzle orifices is joined with a side of the passage-forming substrate opposite the side where the covering plate is joined. Moreover, at least a region of the passage-forming substrate facing the piezoelectric element holding portion is formed to be relatively thicker than the outside of the region facing the piezoelectric element holding portion.
A method of manufacturing a liquid discharge head, which includes a pressure generating chamber, a discharge port, and a piezoelectric element formed of a pair of electrode films sandwiching a piezoelectric material film, includes steps of preparing a structure with a single crystal Si layer accumulated above a front surface of an Si substrate through an etching stop layer; forming a buffer layer on the single crystal Si layer; forming, above the buffer layer, the piezoelectric material film which is directed in a preferential orientation to a direction of the polarization through one of the pair of electrode films; forming the pressure generating chamber on the piezoelectric material film; and etching a location corresponding to the piezoelectric material film of the Si substrate from a rear surface of the Si substrate to reach the etching stop layer.
