Acoustic resonator devices and methods with noble metal layer for functionalization

Patent metadata

Field	Value
Publication number	US-10267770-B2
Application number	US-201615334482-A
Country	US
Kind code	B2
Filing date	Oct 26, 2016
Priority date	Jul 27, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A micro-electrical-mechanical system (MEMS) resonator device includes a top side electrode overlaid with an interface layer including a material having a surface (e.g., gold or a hydroxylated oxide) that may be functionalized with a functionalization (e.g., specific binding) material. The interface layer and/or an overlying blocking layer are precisely patterned to control locations of the interface layer available to receive a self-assembled monolayer (SAM), thereby addressing issues of misalignment and oversizing of a functionalization zone that would arise by relying solely on microarray spotting. Atomic layer deposition may be used for deposition of the interface layer and/or an optional hermeticity layer. Sensors and microfluidic devices incorporating MEMS resonator devices are also provided.

First claim

What is claimed is:

1. A micro-electrical-mechanical system (MEMS) resonator device comprising:
a substrate;
a bulk acoustic wave resonator structure arranged over at least a portion of the substrate, the bulk acoustic wave resonator structure including a piezoelectric material, a top side electrode arranged over a portion of the piezoelectric material, and a bottom side electrode arranged between the piezoelectric material and the substrate, wherein a portion of the piezoelectric material is arranged between the top side electrode and the bottom side electrode to form an active region;
a hermeticity layer arranged over at least a portion of the top side electrode, the hermeticity layer comprising a dielectric material including a water vapor transmission rate of no greater than 0.1 (g/m 2 /day);
an interface layer arranged over at least a portion of the hermeticity layer, the interface layer comprising interface layer material including gold or another noble metal, wherein less than an entirety of the piezoelectric material is overlaid with interface layer material that is available to receive a self-assembled monolayer (SAM); and
a self-assembled monolayer arranged over at least a portion of the interface layer;
wherein at least a portion of each of the hermeticity layer, the interface layer, and the self-assembled monolayer is arranged over the active region.

2. The MEMS resonator device of claim 1 , wherein the interface layer is arranged over less than an entirety of the piezoelectric material.

3. The MEMS resonator device of claim 1 , further comprising a patterned blocking layer arranged over at least one portion of the interface layer.

4. The MEMS resonator device of claim 3 , wherein the patterned blocking layer comprises at least one of silicon nitride, silicon carbide, photoresist, polyimide, parylene, or poly(ethylene glycol).

5. The MEMS resonator device of claim 1 , further comprising at least one functionalization material arranged over at least a portion of the self-assembled monolayer, wherein at least a portion of the at least one functionalization material is registered with the active region.

6. The MEMS resonator device of claim 1 , wherein the hermeticity layer comprises an oxide, a nitride, or an oxynitride dielectric material.

7. The MEMS resonator device of claim 1 , wherein the bulk acoustic wave resonator structure comprises a hexagonal crystal structure piezoelectric material that comprises a c-axis having an orientation distribution that is predominantly non-parallel to normal of a face of the substrate.

8. A sensor comprising the MEMS resonator device of claim 1 .

9. A fluidic device comprising the MEMS resonator device of claim 5 , and a fluidic passage arranged to conduct a liquid to contact the at least one functionalization material.

10. A method for biological or chemical sensing, the method comprising:
supplying a fluid containing a target species into the fluidic passage of the fluidic device according to claim 9 , wherein said supplying is configured to cause at least some of the target species to bind to the at least one functionalization material;
inducing a bulk acoustic wave in the active region; and
sensing a change in at least one of a frequency property, a magnitude property, or a phase property of the bulk acoustic wave resonator structure to indicate at least one of presence or quantity of target species bound to the at least one functionalization material.

11. A method for using a micro-electrical-mechanical system (MEMS) resonator device that comprises a substrate; a bulk acoustic wave resonator structure arranged over at least a portion of the substrate, the bulk acoustic wave resonator structure including a piezoelectric material, a top side electrode arranged over a portion of the piezoelectric material, and a bottom side electrode arranged between the piezoelectric material and the substrate, wherein a portion of the piezoelectric material is arranged between the top side electrode and the bottom side electrode to form an active region; a hermeticity layer arranged over at least a portion of the top side electrode, the hermeticity layer comprising a dielectric material including a water vapor transmission rate of no greater than 0.1 (g/m 2 /day); an interface layer arranged over at least a portion of the hermeticity layer and comprising interface layer material including gold or another noble metal, wherein less than an entirety of the piezoelectric material is overlaid with interface layer material that is available to receive a self-assembled monolayer (SAM); a first self-assembled monolayer arranged over at least a portion of the interface layer; and a first functionalization material arranged over at least a portion of the first self-assembled monolayer; wherein at least a portion of each of the hermeticity layer, the interface layer, and the first self-assembled monolayer is arranged over the active region, the method comprising:
removing the first self-assembled monolayer and the first functionalization material, together with any analyte optionally bound to the first functionalization material, from the MEMS resonator device;
forming a second self-assembled monolayer over at least a portion of the interface layer; and
depositing a second functionalization material over at least a portion of the second self-assembled monolayer, wherein the second functionalization material is registered with at least a portion of the active region.

12. The method of claim 11 , wherein the second functionalization material comprises substantially a same composition as the first functionalization material.

13. The method of claim 11 , wherein the removing of the first self-assembled monolayer and the first functionalization material from the MEMS resonator device, and any analyte optionally bound to the first functionalization material, comprises chemical or electrochemical desorption of the first self-assembled monolayer, and rinsing of desorbed first self-assembled monolayer material from the MEMS resonator device.

14. The method of claim 11 , wherein the removing of the first self-assembled monolayer and the first functionalization material from the MEMS resonator device, together with any analyte optionally bound to the first functionalization material, comprises photooxidation of the first self-assembled monolayer, and rinsing of photooxidized first self-assembled monolayer material from the MEMS resonator device.

15. A method for fabricating a micro-electrical-mechanical system (MEMS) resonator device, the method comprising:
forming a bulk acoustic wave resonator structure including a piezoelectric material, a top side electrode arranged over a portion of the piezoelectric material, and a bottom side electrode arranged between the piezoelectric material and a substrate, wherein a portion of the piezoelectric material is arranged between the top side electrode and the bottom side electrode to form an active region;
depositing a hermeticity layer over at least a portion of the top side electrode, the hermeticity layer comprising a dielectric material including a water vapor transmission rate of no greater than 0.1 (g/m 2 /day);
depositing an interface layer over at least a portion of the hermeticity layer, the interface layer comprising interface layer material including gold or another noble metal, wherein less than an entirety of the piezoelectric material is overlaid with interface layer material that is available to receive a self-assembled monolayer (SAM); and
forming a self-assembled monolayer over at least a portion of the interface layer, wherein at least a portio

Assignees

• Qorvo Us Inc

Inventors

• Ryder Matthew
• Rivas Rio

Classifications

• G01N2291/0255

  (Bio)chemical reactions, e.g. on biosensors · CPC title

• G01N2291/0426

  Bulk waves, e.g. quartz crystal microbalance, torsional waves · CPC title

• G01N29/2437

  Piezoelectric probes · CPC title

• H03H9/175

  Acoustic mirrors · CPC title

• H03H3/02

  for the manufacture of piezoelectric or electrostrictive resonators or networks (H03H3/08 takes precedence) · CPC title