JP2007143125A5 - - Google Patents

Claims (10)

A piezoelectric resonator that vibrates at a predetermined frequency,
A piezoelectric layer composed of a piezoelectric thin film;
An upper electrode formed on one main surface of the piezoelectric layer;
A lower electrode formed on the other main surface of the piezoelectric layer;
A substrate,
A support portion provided between the piezoelectric layer and the substrate;
The support portion is provided at a position where neither the lower electrode nor the upper electrode overlaps in the vertical projection direction ,
A region where the lower electrode, the piezoelectric layer, and the upper electrode overlap in the vertical projection direction is a vibrating portion,
The support part is provided in a shape and position that is non-rotationally symmetric with respect to the vibration center point of the vibration part, or in a shape and position that is non-symmetrical with respect to a straight line passing through the vibration center point of the vibration part. It is characterized Rukoto, piezoelectric resonators.   The piezoelectric resonator according to claim 1, wherein the support portion is configured by a plurality of support columns.   The support portion is provided at a position where a maximum linear distance to the lower electrode is larger than a maximum linear distance between an outer peripheral end of the upper electrode and an outer peripheral end of the lower electrode. The piezoelectric resonator according to 1.   The piezoelectric resonator according to claim 1, wherein the support portion is made of a conductive material. A method for manufacturing a piezoelectric resonator according to claim 1 ,
Forming a piezoelectric layer on the first substrate;
Forming a lower electrode on one main surface of the piezoelectric layer;
Forming a first support layer on one main surface of the piezoelectric layer excluding a region where the lower electrode is formed;
Forming a second support layer on the second substrate;
Bonding the first support layer and the second support layer;
Separating the first substrate after the bonding step, and transferring the piezoelectric layer on which the lower electrode is formed from the first substrate to the second substrate;
Forming an upper electrode on the other principal surface of the piezoelectric layer that does not overlap with the first and second support layer in the vertical projection direction. The manufacturing method according to claim 5 , wherein the bonding step is performed by eutectic crystal bonding between the first support part layer and the second support part layer. 6. The manufacturing method according to claim 5 , wherein the first support part layer and the second support part layer are multilayer films containing at least gold tin (AuSn) or gold silicon (AuSi).   A piezoelectric filter comprising a plurality of piezoelectric resonators, comprising at least one piezoelectric resonator according to claim 1. A duplexer including a transmission filter and a reception filter, wherein the piezoelectric filter according to claim 8 is provided in at least one of the transmission filter and the reception filter. A communication device including an antenna, a transmission circuit, and a reception circuit, wherein the duplexer according to claim 9 is used as at least one of a common connection portion between the antenna, the transmission circuit, and the reception circuit, the transmission circuit, and the reception circuit. Equipped with communication equipment.