Structure and fabrication procedures to achieve high-Q and low insertion loss film bulk acoustic resonators

A method for forming a device in a substrate comprising:

• depositing a first portion of a first electrode onto the substrate;
• depositing a piezoelectric layer on the substrate and a portion of the first portion of a first electrode, the piezoelectric film layer having a first surface proximate the substrate and a second surface remote from the substrate;
• placing a second electrode on the second surface of the piezoelectric layer;
• removing a portion of the substrate under the piezoelectric layer and under the portion of the first electrode;
• and
• depositing a second portion of the first electrode onto the first surface of the piezoelectric film layer and onto the first portion of the first electrode.

A method for forming a device in a substrate comprising:

• placing a first portion of a first electrode onto the substrate;
• placing a piezoelectric layer on the substrate and on a portion of the first portion of the first electrode, the piezoelectric layer having a first surface proximate the substrate and a second surface remote from the substrate;
• placing a second electrode on the second surface of the piezoelectric layer;
• removing a portion of the substrate under the piezoelectric layer and under the portion of the first electrode;
• placing a second portion of the first electrode onto the first surface of the piezoelectric film layer and onto the first portion of the first electrode.

A method for forming a device in a substrate comprising:

• depositing a dielectric layer onto the substrate;
• depositing a seed layer onto the dielectric layer;
• depositing a first portion of a first electrode onto the dielectric layer;
• depositing a piezoelectric layer on the dielectric layer and on a portion of the first portion of the first electrode, the piezoelectric layer having a first surface proximate the substrate and a second surface remote from the substrate;
• placing a second electrode on the second surface of the piezoelectric layer;
• removing a portion of the substrate under the piezoelectric layer and under the portion of the first electrode;
• removing a portion of the dielectric layer under the piezoelectric layer and under the portion of the first electrode;
• removing a portion of the seed layer under the piezoelectric layer and under the portion of the first electrode;
• depositing a second portion of the first electrode onto the first surface of the piezoelectric film layer and onto the first portion of the first electrode.