# US 2021/0082992 A1 · Methods for fabricating mechanically stacked multicolor focal plane arrays and detection devices

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2021/0082992 A1
- Document ID: US20210082992A1
- Status: Published application
- Kind: A1
- Application number: 17/018,944
- Filed: 2020-09-11
- Published: 2021-03-18
- Earliest claimed: 2019-09-12
- Assignees: L3 Cincinnati Electronics Corporation
- Applicants: L3 Cincinnati Electronics Corporation
- Inventors: Yajun Wei; Daniel Chmielewski; Nansheng Tang; Darrel Endres; Michael Garter; Mark Greiner
- Web page: https://patentgrep.com/patent/US20210082992A1

## CPC

- H10F 39/1847: {Multispectral infrared image sensors having a stacked structure, e.g. NPN, NPNPN or multiple quantum well [MQW] structures}
- H10F 39/026: {Wafer-level processing}
- H10F 39/1843: {of the hybrid type}
- H10F 39/805: {Coatings}
- H10F 39/811: {Interconnections}
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION

## Abstract

Methods of fabricating multicolor, stacked detector devices and focal plane arrays are disclosed. In one embodiment, a method of fabricating a stacked multicolor device includes forming a first detector by depositing a first detector structure on a first detector substrate, and depositing a first ground plane on the first detector structure, wherein the first ground plane is transmissive to radiation in a predetermined spectral band. The method further includes bonding an optical carrier wafer to the first ground plane, removing the first detector substrate, and forming a second detector. The second detector is formed by depositing a second detector structure on a second detector substrate, and depositing a second ground plane on the second detector structure. The method further includes depositing a dielectric layer on one of the first detector structure and the second ground plane, bonding the first detector to the second detector, and removing the second detector substrate.

## Claims

### Claim 1

A method of fabricating a stacked multicolor device, the method comprising:
forming a first detector by:
depositing a first detector structure on a first detector substrate; and
depositing a first ground plane on the first detector structure, wherein the first ground plane is transmissive to radiation in a predetermined spectral band;
bonding an optical carrier wafer to the first ground plane;
removing the first detector substrate;
forming a second detector by:
depositing a second detector structure on a second detector substrate; and
depositing a second ground plane on the second detector structure, wherein the second ground plane is transmissive to radiation in the predetermined spectral band;
depositing a dielectric layer on one of the first detector structure and the second ground plane;
bonding the first detector to the second detector such that the dielectric layer is positioned between the first detector structure and the second ground plane; and
removing the second detector substrate.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
forming an additional detector by:
depositing an additional detector structure on an additional detector substrate; and
depositing an additional ground plane on the additional detector structure, wherein the additional ground plane is transmissive to radiation in the predetermined spectral band;
depositing an additional dielectric layer on one of the second detector structure and the additional ground plane; and
bonding the second detector to the additional detector such that the additional dielectric layer is positioned between the second detector structure and the additional ground plane.

### Claim 3 (depends on 1)

The method of claim 1, further comprising reticulating the first detector and reticulating the second detector prior to bonding the first detector to the second detector.

### Claim 4 (depends on 1)

The method of claim 1, further comprising reticulating the first detector and the second detector after bonding the first detector to the second detector.

### Claim 5 (depends on 1)

The method of claim 1, wherein the first detector is bonded to the second detector by direct wafer bonding.

### Claim 6 (depends on 1)

The method of claim 1, wherein the first detector is bonded to the second detector by an adhesive layer.

### Claim 7 (depends on 1)

The method of claim 1, further comprising:
forming one or more first insulated conductive signal paths through the first detector and the second detector of the plurality of detector devices; and
forming one or more second insulated conductive signal paths through the second detector of the plurality of detector devices.

### Claim 8

A method of fabricating a stacked multicolor device, the method comprising:
forming a first detector by:
depositing a first ground plane on a first detector substrate, wherein the first ground plane is transmissive to radiation in a predetermined spectral band; and
depositing a first detector structure on the first ground plane;
forming a second detector by:
depositing a second ground plane on a second detector substrate, wherein the second ground plane is transmissive to radiation in the predetermined spectral band; and
depositing a second detector structure on the second ground plane;
depositing a dielectric layer on one of the second ground plane and the first detector structure;
bonding the first detector to the second detector;
removing the first detector substrate;
bonding an optical carrier wafer to the first ground plane; and
removing the second detector substrate.

### Claim 9 (depends on 8)

The method of claim 8, further comprising:
forming an additional detector by:
depositing an additional ground plane on an additional detector substrate, wherein the additional ground plane is transmissive to radiation in the predetermined spectral band; and
depositing an additional detector structure on the additional ground plane;
depositing an additional dielectric layer on one of the additional ground plane and the second detector structure.

### Claim 10 (depends on 8)

The method of claim 8, further comprising reticulating the first detector and reticulating the second detector prior to bonding the first detector to the second detector.

### Claim 11 (depends on 8)

The method of claim 8, further comprising reticulating the first detector and the second detector after bonding the first detector to the second detector.

### Claim 12 (depends on 8)

The method of claim 8, wherein the first detector is bonded to the second detector by direct wafer bonding.

### Claim 13 (depends on 8)

The method of claim 8, wherein the first detector is bonded to the second detector by an adhesive.

### Claim 14 (depends on 8)

The method of claim 8, further comprising:
forming one or more first insulated conductive signal paths through the first detector and the second detector of the plurality of detector devices; and
forming one or more second insulated conductive signal paths through the second detector of the plurality of detector devices.

### Claim 15

A method of fabricating a multicolor focal plane array, the method comprising:
forming a first detector layer by:
depositing a first detector structure on a first detector substrate; and
depositing a first ground plane on the first detector structure, wherein the first ground plane is transmissive to radiation in a predetermined spectral band;
bonding an optical carrier wafer to the first ground plane;
removing the first detector substrate;
forming a second detector layer by:
depositing a second detector structure on a second detector substrate; and
depositing a second ground plane on the second detector structure, wherein the second ground plane is transmissive to radiation in the predetermined spectral band;
depositing a dielectric layer on one of the first detector structure and the second ground plane;
bonding the first detector layer to the second detector layer such that the dielectric layer is positioned between the first detector structure and the second ground plane;
removing the second detector substrate; and
forming a plurality of detector devices in the first detector layer and the second detector layer by one of the following:
prior to bonding the first detector layer to the second detector layer, individually reticulating the first detector layer and the second detector layer to form the plurality of detector devices; and
after bonding the first detector layer to the second detector layer, reticulating the first detector layer and the second detector layer to form the plurality of detector devices; and
wherein each detector device of the plurality of detector devices comprise a first detector formed at least by the first detector structure and the first ground plane and a second detector formed at least by the second detector structure and the second ground plane.

### Claim 16 (depends on 15)

The method of claim 15, wherein the first detector is bonded to the second detector by direct wafer bonding.

### Claim 17 (depends on 15)

The method of claim 15, wherein the first detector is bonded to the second detector by an adhesive.

### Claim 18 (depends on 15)

The method of claim 15, further comprising:
forming first insulated conductive signal paths through the first detector and the second detector of the plurality of detector devices;
forming second insulated conductive signal paths through the second detector of the plurality of detector devices; and
coupling the first detector and the second detector of the plurality of detector devices to a read-out integrated circuit such that the first insulated conductive signal paths electrically couple the first detector structure of the plurality of detector devices to a plurality of first electrical contacts of the read-out integrated circuit and the second insulated conductive signal paths electrically couple the second detector structure of the plurality of detector devices to a plurality of second electrical contacts of the read-out integrated circuit.