Support and decoupling structure for an acoustic resonator, acoustic resonator and corresponding integrated circuit

Abstract

An acoustic resonator assembly includes a layer of high-acoustic-impedance material and a layer of low-acoustic-impedance material made of a low-electrical-permittivity material. This assembly may support the resonator over an interconnect layer or act as a decoupling assembly between two active elements of the resonator. The assembly may alternatively include three low-acoustic impedance layers. Alternatively, the assembly may include three acoustic impedance layers wherein two of the layers are low acoustic impedance layers and the third layer has a higher acoustic impedance than the first two or alternatively is a high-acoustic impedance layer.

1 . A decoupling structure, comprising: 
 at least one assembly positioned between first and second acoustic resonators, comprising: 
 a layer of high-acoustic-impedance material; and  
 a layer of low-acoustic-impedance material made of a low-electrical-permittivity material.  
   
   
   
       2 . The structure according to  claim 1 , wherein the layer of low-acoustic-impedance material is placed between one of the two acoustic resonators and said layer of high-acoustic-impedance material.  
   
   
       3 . The structure according to  claim 1 , wherein the layer of high-acoustic-impedance material is made of a same material as an electrode of one of the acoustic resonators.  
   
   
       4 . The structure according to  claim 1 , wherein the low-acoustic-impedance material comprises SiOC.  
   
   
       5 . The structure according to  claim 1 , wherein the low-acoustic-impedance material comprises at least 90% SiOC in weight.  
   
   
       6 . The structure according to  claim 1 , wherein the low-acoustic-impedance material comprises porous SiOC.  
   
   
       7 . The structure according to  claim 1 , wherein the layer of low-acoustic-impedance material comprises a plurality of sublayers comprising SiOC.  
   
   
       8 . The structure according to  claim 1 , wherein the high-acoustic-impedance material comprises at least one material selected in the group consisting of: aluminum, copper, nickel, gold, platinum, molybdenum.  
   
   
       9 . An acoustic resonator, comprising: 
 at least two active elements; and    a decoupling assembly placed between pairs of active elements comprising at least a layer of low-acoustic-impedance material made of a low-electrical-permittivity material.    
   
   
       10 . The resonator according to  claim 9 , wherein an active element comprises at least one piezoelectric layer placed between electrodes.  
   
   
       11 . The resonator according to  claim 9 , wherein the decoupling assembly is placed between an upper electrode of a first active element and a lower electrode of a second active element.  
   
   
       12 . The resonator according to  claim 9 , wherein the low-acoustic-impedance material comprises a SiOC material.  
   
   
       13 . The resonator according to  claim 9 , wherein an electrode comprises at least one material elected in the group consisting of: aluminum, copper, nickel, gold, platinum, molybdenum.  
   
   
       14 . The resonator according to  claim 9 , wherein the decoupling assembly comprises no more than one layer of low-acoustic-impedance material.  
   
   
       15 . The resonator according to  claim 9 , wherein the decoupling assembly comprises two layers of low-acoustic-impedance material.  
   
   
       16 . The resonator according to  claim 9 , wherein the decoupling assembly comprises three layers of low-acoustic-impedance material.  
   
   
       17 . An integrated circuit, comprising: 
 a substrate;    a set of interconnects; and    an acoustic resonator that is provided with at least two active elements and with a decoupling layer positioned between each pair of active elements.    
   
   
       18 . The circuit according to  claim 17 , wherein the acoustic resonator is placed on the set of interconnects.  
   
   
       19 . The circuit according to  claim 17 , wherein the acoustic resonator is placed near the set of interconnects.  
   
   
       20 . The circuit according to  claim 17 , wherein a first acoustic resonator comprises a support on an interconnect layer, the support including at least one bilayer assembly comprising a layer of high-acoustic-impedance material and a layer of low-acoustic-impedance material made of a low-electrical-permittivity material.  
   
   
       21 . The circuit according to  claim 17 , wherein the decoupling layer comprises at least a layer of low-acoustic-impedance material.  
   
   
       22 . The circuit according to  claim 17 , wherein the low-acoustic-impedance material comprises a SiOC material.  
   
   
       23 . The circuit according to  claim 20 , wherein the high-acoustic-impedance material comprises at least one material selected in the group consisting of: aluminum nitride, copper, nickel, tungsten, gold, platinum, molybdenum.  
   
   
       24 . A decoupling structure, comprising: 
 at least one assembly positioned between a first and second acoustic resonators, comprising: 
 a first layer of low-acoustic-impedance material having a first acoustic impedance; and  
 a second layer of low-acoustic-impedance material having a second acoustic impedance.  
   
   
   
       25 . The structure according to  claim 24 , wherein the first layer of low-acoustic-impedance material comprises a layer of SiOC.  
   
   
       26 . The structure according to  claim 25 , wherein the first layer of low-acoustic-impedance material comprises a layer at least 90% SiOC in weight.  
   
   
       27 . The structure according to  claim 25 , wherein the second layer of low-acoustic-impedance material comprises a layer of porous SiOC.  
   
   
       28 . A decoupling structure, comprising: 
 at least one assembly positioned between a first and second acoustic resonators, comprising: 
 a first and second layers of low-acoustic-impedance material having a first acoustic impedance;  
 a third layer of low-acoustic-impedance material having a second acoustic impedance.  
   
   
   
       29 . The structure according to  claim 28 , wherein at least one of the layers of low-acoustic-impedance material comprises a layer of SiOC.  
   
   
       30 . The structure according to  claim 29 , wherein the at least one layer of low-acoustic-impedance material comprises a layer at least 90% SiOC in weight.  
   
   
       31 . The structure according to  claim 29 , wherein at least one other layer of low-acoustic-impedance material comprises a layer of porous SiOC.  
   
   
       32 . The structure according to  claim 28 , wherein the third layer is a middle layer between the first and second layers.  
   
   
       33 . The structure according to  claim 32 , wherein the second acoustic impedance is higher than the first acoustic impedance.  
   
   
       34 . A decoupling structure, comprising: 
 at least one assembly positioned between a first and second acoustic resonators, comprising: 
 a first layer of low-acoustic-impedance material having a first acoustic impedance;  
 a second layer of low-acoustic-impedance material having a second acoustic impedance;  
 a layer of high-acoustic-impedance material.  
   
   
   
       35 . The structure according to  claim 34 , wherein at least one of the first and second layers of low-acoustic-impedance material comprises a layer of SiOC.  
   
   
       36 . The structure according to  claim 35 , wherein the at least one layer of low-acoustic-impedance material comprises a layer at least 90% SiOC in weight.  
   
   
       37 . The structure according to  claim 35 , wherein the other of the first and second layers of low-acoustic-impedance material comprises a layer of porous SiOC.  
   
   
       38 . The structure according to  claim 34 , wherein the third layer is a middle layer between the first and second layers.  
   
   
       39 . The structure according to  claim 34 , wherein the second acoustic impedance is higher than the first acoustic impedance.  
   
   
       40 . The structure according to  claim 34 , wherein the first and second acoustic impedances are the same.  
   
   
       41 . An acoustic resonator, comprising: 
 a first, second and third active elements;    a support positioned under the first active element comprising a first high acoustic impedance layer and a first low acoustic impedance layer;    a first decoupling assembly positioned between the first and second active elements comprising plural layers of acoustic-impedance material; and    a second decoupling assembly positioned between the second and third active elements comprising plural layers of acoustic-impedance material.    
   
   
       42 . The resonator of  claim 41  wherein at least one of the first and second decoupling assemblies comprises: 
 a first layer of low-acoustic-impedance material having a first acoustic impedance; and    a second layer of low-acoustic-impedance material having a second acoustic impedance.    
   
   
       43 . The resonator of  claim 41  wherein at least one of the first and second decoupling assemblies comprises: 
 a first layer of low-acoustic-impedance material having a first acoustic impedance;    a second layer of low-acoustic-impedance material having a second acoustic impedance; and    a layer of high-acoustic-impedance material.