Aluminum nitride (AlN) devices with infrared absorption structural layer

Patent metadata

Field	Value
Publication number	US-9511994-B2
Application number	US-201414480051-A
Country	US
Kind code	B2
Filing date	Sep 8, 2014
Priority date	Nov 28, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A micro-electro-mechanical system device is disclosed. The micro-mechanical system device comprises a first silicon substrate comprising: a handle layer comprising a first surface and a second surface, the second surface comprises a cavity; an insulating layer deposited over the second surface of the handle layer; a device layer having a third surface bonded to the insulating layer and a fourth surface; a piezoelectric layer deposited over the fourth surface of the device layer; a metal conductivity layer disposed over the piezoelectric layer; a bond layer disposed over a portion of the metal conductivity layer; and a stand-off formed on the first silicon substrate; wherein the first silicon substrate is bonded to a second silicon substrate, comprising: a metal electrode configured to form an electrical connection between the metal conductivity layer formed on the first silicon substrate and the second silicon substrate.

First claim

What is claimed is:

1. A micro-electro-mechanical system device, comprising:
a first silicon substrate comprising:
a handle layer comprising a first surface and a second surface, the second surface comprises a cavity;
an insulating layer deposited over the second surface of the handle layer;
a device layer having a third surface bonded to the insulating layer and a fourth surface;
a piezoelectric layer deposited over the fourth surface of the device layer;
a metal conductivity layer disposed over the piezoelectric layer;
a bond layer disposed over a portion of the metal conductivity layer; and
a stand-off formed on the first silicon substrate;

wherein the first silicon substrate is bonded to a complementary metal-oxide-semiconductor (CMOS) substrate, comprising:
a metal electrode configured to form an electrical connection between the metal conductivity layer formed on the first silicon substrate and the CMOS substrate.

2. The device of claim 1 , wherein the stand-off is formed on the piezoelectric layer.

3. The device of claim 1 , wherein the stand-off is formed of a silicon layer or a silicon dioxide layer deposited on the device layer.

4. The device of claim 1 , wherein the stand-off is formed of silicon dioxide deposited on the piezoelectric layer.

5. The device of claim 1 , wherein the piezoelectric layer is patterned and etched to form a sidewall in the piezoelectric layer.

6. The device of claim 5 , further comprising a first dielectric layer between the piezoelectric layer and the metal conductive layer.

7. The device of claim 6 , further comprising a second dielectric layer disposed on the sidewall of the piezoelectric layer.

8. The device of claim 7 , further comprising an opening in the handle layer to expose the device layer.

9. The device of claim 8 , further comprising an orifice in the device layer to expose the piezoelectric layer.

10. The device of claim 8 , further comprising an aperture in the device layer.

11. The device of claim 1 , wherein the device layer is selectively or partially removed.

12. The device of claim 1 , wherein the piezoelectric layer comprises aluminum nitride.

13. The device of claim 1 , wherein the piezoelectric layer comprises: an aluminum nitride (AlN) seed layer, a bottom metal layer, and an aluminum nitride (AlN) layer.

14. The device of claim 1 , further comprising an infra-red (IR) absorption layer deposited on a portion of the device layer.

15. The device of claim 1 , further comprising an infra-red (IR) absorption layer deposited on a portion of the piezoelectric layer.

Assignees

• Invensense Inc

Inventors

• Tsai Julius Ming-Lin
• Daneman Michael J

Classifications

• B81C2201/019

  Bonding or gluing multiple substrate layers · CPC title

• B81B2207/07

  Interconnects · CPC title

• B81C1/00182 Primary

  Arrangements of deformable or non-deformable structures, e.g. membrane and cavity for use in a transducer · CPC title

• B81C1/00301

  Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias · CPC title

• B81B2201/032

  Bimorph and unimorph actuators, e.g. piezo and thermo · CPC title