Method for making piezoelectric resonator and surface acoustic wave device using hydrogen implant layer splitting

A method for making a thin film resonator, the method comprising the steps of:

• implanting a single-crystal piezoelectric material with hydrogen ions;
• depositing a first metal electrode onto the single-crystal piezoelectric material;
• bonding the surface of the first metal electrode to the surface of a substrate that contains an acoustic Bragg reflector to form a composite;
• causing the single-crystal piezoelectric material to split at the peak of the hydrogen implant;
• and
• depositing a second metal electrode on the top surface of the composite in selected locations to produce a thin film resonator with top and bottom side first and second metal electrodes.

A method for making a thin film resonator, the method comprising the steps of:

• implanting a single-crystal piezoelectric material with hydrogen ions;
• forming a first metal electrode on single-crystal piezoelectric material;
• depositing material layers for a Bragg reflector onto the surface of the first metal electrode;
• bonding the surface to the Bragg reflector material to a substrate to form a composite;
• causing the single-crystal piezoelectric material to split at the peak of the hydrogen implant;
• and depositing a second metal electrode on the top surface of the composite in selected locations to produce a thin film resonator with top and bottom side first and second metal electrodes.

A method for making a thin film resonator with an air cavity beneath a piezoelectric resonator, the method comprising the steps of:

• implanting hydrogen ions into piezoelectric material;
• depositing a first metal electrode onto the surface of the piezoelectric material;
• optionally depositing a stiffener material on top of the first metal electrode;
• etching a depression on the top surface of a substrate;
• bonding the piezoelectric/first metal electrode to the substrate to form a composite;
• causing the piezoelectric material to split at the location of the peak of the hydrogen implant;
• and
• depositing a second metal electrode onto the top surface of the piezoelectric material.

A method for making a thin film resonator with an air cavity beneath a piezoelectric resonator, the method comprising the steps of:

• implanting hydrogen ions into single-crystal piezoelectric material;
• depositing a first metal electrode onto the surface of the single-crystal piezoelectric material;
• optionally depositing a stiffener material on top of the first metal electrode;
• etching a depression into the surface of the piezoelectric material;
• bonding the piezoelectric/first metal electrode to a substrate;
• causing the single-crystal piezoelectric material to split at the location of the peak of the hydrogen ion implantation;
• and
• depositing a second metal electrode onto the top surface of the piezoelectric material;
• and
• wherein the depression in the surface of the piezoelectric material forms a cavity in the composite.

A method for making a thin film resonator with an air cavity beneath a piezoelectric resonator comparing:

• implanting hydrogen ions into single-crystal piezoelectric material;
• depositing a first metal electrode onto the surface of the single-crystal piezoelectric material;
• optionally depositing a stiffener material on top of the first metal electrode;
• bonding the single-crystal piezoelectric material/first metal electrode to a substrate which has an etch stop layer on the surface thereof to form a composite;
• causing the single-crystal piezoelectric material to split at the location of the peak of the hydrogen ion implantation and form a thin piezoelectric layer, which is bonded to the substrate;
• etching a cavity in the substrate;
• and
• depositing a second metal electrode onto the top surface of the piezoelectric material.

A method for making a surface acoustic wave device, the method comprising the steps of:

• hydrogen ion implanting into a single crystal piezoelectric material;
• bonding said single crystal piezoelectric material to a high acoustic velocity substrate material to form a composite;
• causing the single-crystal piezoelectric material to split at the location of the peak of the hydrogen ion implantation to form a thin layer single crystal piezoelectric material bonded to said high acoustic velocity substrate;
• and
• forming input and output metal transducer electrodes on top of the single crystal piezoelectric material.

A method for making a thin film resonator, the method comprising the steps of:

• implanting a single-crystal piezoelectric material with hydrogen ions;
• depositing a first metal electrode onto the single-crystal piezoelectric material;
• forming an acoustic Bragg reflector on metal electrode;
• bonding the surface of the metal electrode to the surface of a substrate that contains an acoustic Bragg reflector to form a composite;
• causing the hydrogen gas in the piezoelectric material to expand and to split the piezoelectric single-crystal at the peak of the hydrogen implant;
• and
• depositing a metal on the top surface of the composite to produce a thin film resonator with top and bottom side metal electrodes.