COLUMNAR STRUCTURE FILM, METHOD OF FORMING THE SAME, PIEZOELECTRIC ELEMENT, LIQUID DISCHARGE DEVICE, AND PIEZOELECTRIC TYPE ULTRASONIC VIBRATOR

摘要

PROBLEM TO BE SOLVED: To provide a columnar structure film such as a piezoelectric film, excellent in withstand voltage and driving durability, formed without requiring a complicated process.;SOLUTION: The columnar structure film is formed on a substrate and includes a number of columnar bodies extending in a non-parallel direction with respect to the surface of the substrate. The film is formed by a vapor growth method and satisfies an expression: GSmax2.0 GSmin where GSmax represents a maximum value of an average column diameter in the horizontal direction as viewed in the film thickness direction and GSmin represents a minimum value thereof. In a film structure where GSmax/GSmin is a large value, the probability of penetrating through a grain boundary in the film thickness direction from the lower surface to the upper surface of the film is decreased and leak paths are reduced, which makes it possible to improve withstand voltage and driving durability.;COPYRIGHT: (C)2011,JPO&INPIT