Liquid ejecting head, liquid ejecting apparatus, piezoelectric element, and method for manufacturing piezoelectric element

A piezoelectric element comprising:

• a piezoelectric layer;
• a pair of electrodes;
• and
• a wiring layer coupled to the electrodes, the wiring layer having an adhesion layer and a conductive layer on the adhesion layer, the adhesion layer containing at least one selected from nickel, chromium, titanium, and tungsten, wherein:
• the piezoelectric element has an insulating film at least between the wiring layer and the electrodes;
• and
• the wiring layer and each of the electrodes are coupled via a contact hole created through the insulating film.

A method for manufacturing a piezoelectric element having a piezoelectric layer, a pair of electrodes, and a wiring layer coupled to the electrodes, the method comprising:

• with the electrodes exposed, forming an insulating film protecting the electrodes at least in a region where the wiring layer is to be formed, and creating contact holes through the insulating film;
• forming an adhesion layer on the insulating film and on the electrodes in the contact holes, the adhesion layer containing at least one selected from nickel, chromium, titanium, and tungsten;
• forming the wiring layer by depositing a conductive layer on the adhesion layer;
• and
• patterning the wiring layer by wet-etching at least the adhesion layer.