PIEZOELECTRIC ELEMENT UNIT AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a low cost protection layer which is capable of having a resistance to a film forming condition in a hydrothermal synthesis method for a PZT and superior in edge coverage without having pin holes. SOLUTION: A whole surface of a silicon substrate as a substrate 13 not including titanium is covered with a nickel protection layer 15a having a thickness of roughly 5 μm by electroless plating. A titanium layer 91 is formed on a portion where a PZT layer 92 is to be selectively formed by a mask vapor deposition method and the PZT layer 92 is formed on the portion by a hydrothermal method. An electrode 93 is formed on the face of the PZT layer 92 by a mask vapor deposition method. The cost of the nickel protection layer 15a is lower than that of the other metallic layer. It is possible to form a thick layer by plating and the layer becomes a protection layer superior in edge coverage without having pin holes. It is possible to form a bimorph having a small thickness from the nickel protection layer 15a and PZT layer 92.