Electronic component, manufacturing method for the same, and filter, duplexer, and electronic communication apparatus using the same

Abstract

A manufacturing method for an electronic component includes a process of forming a lower electrode and a dummy electrode, which are electrically connected to each other, on a substrate, and a process of forming a piezoelectric thin film on the dummy electrode and the lower electrode while a predetermined bias potential is applied to the lower electrode via the dummy electrode. In this method, the piezoelectric thin film is formed on the lower electrode by stabilizing the potential of the lower electrode, thereby decreasing the surface roughness of the piezoelectric thin film. It is thus possible to manufacture an electric component that exhibits excellent piezoelectric characteristics, in which the electromechanical coupling coefficient and the quality of a resonator are increased.

What is claimed is:  
     
         1 . An electronic component comprising: 
 a substrate;    an electrode disposed on the substrate; and    a piezoelectric thin film disposed on the electrode;    wherein a surface roughness of the piezoelectric thin film is about 10 nm or smaller.    
     
     
         2 . An electronic component according to  claim 1 , wherein the piezoelectric thin film is formed while a predetermined bias potential is applied to the electrode.  
     
     
         3 . An electronic component comprising a resonator, said resonator comprising: 
 a substrate; and    a vibrator disposed on the substrate, the vibrator including a thin-film portion having at least one layer of a piezoelectric thin film which is interposed by opposing at least one pair of an upper electrode and a lower electrode on first surface and a second surface of the thin-film portion;    wherein the piezoelectric thin film is formed while a predetermined bias potential is applied to the lower electrode, and the surface roughness of the piezoelectric thin film is about 10 nm or smaller.    
     
     
         4 . An electronic component according to  claim 3 , wherein the substrate has one of an opening and a recessed portion, and the vibrator is disposed on said one of the opening and the recessed portion.  
     
     
         5 . An electronic component according to  claim 1 , wherein the piezoelectric thin film includes one element selected from the group consisting of ZnO and AlN.  
     
     
         6 . An electronic component according to  claim 2 , wherein the bias potential ranges from about +50 V to about +300 V.  
     
     
         7 . A filter comprising a circuit and a plurality of the electronic components according to  claim 1 , wherein the electrodes of the electronic components are connected to the circuit of the filter.  
     
     
         8 . A filter comprising a plurality of the electronic components according to  claim 1 , the plurality of the electronic components arranged in a ladder configuration.  
     
     
         9 . A duplexer comprising the filter according to  claim 7 .  
     
     
         10 . A duplexer comprising the filter according to  claim 8 .  
     
     
         11 . An electronic communication apparatus comprising at least one of the electronic component according to  claim 1 , and said at least one electronic component is used for an electronic communication operation.  
     
     
         12 . A method for manufacturing an electronic component, comprising the steps of: 
 forming an electrode on a substrate; and    forming a piezoelectric thin film on the electrode while a predetermined bias potential is applied to the electrode.    
     
     
         13 . A method for manufacturing an electronic component according to  claim 12 , wherein the bias potential ranges from about +50 V to about +300 V.  
     
     
         14 . A method for manufacturing an electronic component according to  claim 12 , wherein the piezoelectric thin film includes one element selected from the group consisting of ZnO and AlN.  
     
     
         15 . A method for manufacturing an electronic component according to  claim 12 , wherein the piezoelectric thin film is formed by using one of ion and plasma.  
     
     
         16 . A method for manufacturing an electronic component according to  claim 12 , wherein the piezoelectric thin film is formed by one of a chemical vapor deposition method and a sputtering method.  
     
     
         17 . A method for manufacturing an electronic component, comprising the steps of: 
 forming a dummy electrode together with a lower electrode on a substrate such that the dummy electrode surrounds a periphery of the lower electrode and that the dummy electrode is electrically connected to the lower electrode;    forming a piezoelectric thin film on the lower electrode and the dummy electrode while a predetermined bias potential is applied to the lower electrode and the dummy electrode;    removing the dummy electrode together with a peripheral portion of the piezoelectric thin film; and    forming an upper electrode on the piezoelectric thin film such that a portion of the upper electrode and a portion of the lower electrode define a pair of vertically opposing excitation electrodes with the piezoelectric thin film therebetween.    
     
     
         18 . A method for manufacturing an electronic component according to  claim 17 , wherein the bias potential ranges from about +50 V to about +300 V.  
     
     
         19 . A method for manufacturing an electronic component according to  claim 17 , wherein the piezoelectric thin film includes one element selected from the group consisting of ZnO and AlN.  
     
     
         20 . A method for manufacturing an electronic component according to  claim 17 , wherein the piezoelectric thin film is formed by using one of ion and plasma.  
     
     
         21 . A method for manufacturing an electronic component according to  claim 17 , wherein the piezoelectric thin film is formed by one of a chemical vapor deposition method and a sputtering method.  
     
     
         22 . A method for manufacturing an electronic component, comprising the steps of: 
 forming an insulating thin film on a substrate;    forming a dummy electrode together with a lower electrode on the insulating thin film such that the dummy electrode surrounds a periphery of the lower electrode and that the dummy electrode is electrically connected to the lower electrode;    forming a piezoelectric thin film on the insulating thin film, the dummy electrode, and the lower electrode while a predetermined bias potential is applied to the dummy electrode and the lower electrode;    removing the dummy electrode together with a peripheral portion of the piezoelectric thin film; and    forming an upper electrode on the piezoelectric thin film such that a portion of the upper electrode and a portion of the lower electrode define a pair of vertically opposing excitation electrodes with the piezoelectric thin film disposed therebetween.    
     
     
         23 . A method for manufacturing an electronic component according to  claim 22 , wherein the bias potential ranges from about +50 V to about +300 V.  
     
     
         24 . A method for manufacturing an electronic component according to  claim 22 , wherein the piezoelectric thin film includes one element selected from the group consisting of ZnO and AlN.  
     
     
         25 . A method for manufacturing an electronic component according to  claim 22 , wherein the piezoelectric thin film is formed by using one of ion and plasma.  
     
     
         26 . A method for manufacturing an electronic component according to  claim 22 , wherein the piezoelectric thin film is formed by one of a chemical vapor deposition method and a sputtering method.