Tdk Corporation

Qualcomm Incorporated

Yukari Inoue

Junichi Kimura

Hisayuki Abe

Miyuki Yanagida

Tomohiro Terada

Susumu Taniguchi

Masataka Kitagami

Provided is a piezoelectric thin film device containing: a first electrode layer; and a piezoelectric thin film. The first electrode layer contains a metal Me having a crystal structure. The piezoelectric thin film contains aluminum nitride having a wurtzite structure. The aluminum nitride contains a divalent metal element Md and a tetravalent metal element Mt. [Al] is an amount of Al contained in the aluminum nitride, [Md] is an amount of Md contained in the aluminum nitride, [Mt] is an amount of Mt contained in the aluminum nitride, ([Md]+[Mt])/([Al]+[Md]+[Mt]) is 36 to 70 atom %. Lis a lattice length of the aluminum nitride in a direction that is approximately parallel to a surface of the first electrode layer with which the piezoelectric thin film is in contact, Lis a lattice length of Me in a direction, and Lis longer than L.

Piezoelectric thin film device

A piezoelectric thin film deviceincludes a conductive layerand a piezoelectric thin filmlaminated directly on a surface of the conductive layer. The piezoelectric thin filmcontains a plurality of crystalline grains having a wurtzite structure, a (001) plane of at least a part of the crystalline grains is oriented in a normal direction Dof the surface of the conductive layer, and a median diameter of the plurality of crystalline grains in a direction parallel to the surface of the conductive layeris 30 nm or more and 80 nm or less.

A piezoelectric thin film comprises aluminum nitride containing a monad and at least one type among a tetrad and a pentad. The piezoelectric thin film having a large electromechanical coupling factor and a small stiffness.

Piezoelectric thin film and bulk acoustic wave filter

A ceramic electronic componentincludes a ceramic bodyin which internal electrodes containing a metal component is buried, and a pair of terminal electrodesprovided to cover both end surfacesof the ceramic body to which the internal electrodes are exposed. Each of the terminal electrodeshas a first electrode layer and a second electrode layer formed by baking a conductive green sheet from a side close to the ceramic body. The second electrode layer contains the metal component diffused from the internal electrodes.

Growing community of inventors

Tokyo, Japan

Yukari Inoue