PIEZOELECTRIC THIN-FILM ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric thin film element having excellent surface morphology of a piezoelectric thin film.SOLUTION: A piezoelectric thin film element includes: a substrate 1; a lower electrode layer 2 formed on the substrate 1; a piezoelectric thin-film buffer layer 3 formed on the lower electrode layer 2 and having granular crystals; a piezoelectric thin-film layer 4 formed on the piezoelectric thin-film buffer layer 3 and having columnar crystals; and an upper electrode layer formed on the piezoelectric thin-film layer 4. The piezoelectric thin-film buffer layer 3 has the granular crystals that are generated by crystals of potassium sodium niobate grown from the lower electrode layer 2 being interrupted. In the granular crystals, a number of grain boundaries exist in in-plane direction, compared to the columnar crystals.