Devices and methods for infrared reference pixels

Patent metadata

Field	Value
Publication number	US-10677656-B2
Application number	US-201715465505-A
Country	US
Kind code	B2
Filing date	Mar 21, 2017
Priority date	Dec 31, 2012
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A device is disclosed including a substrate and a floating blinded infrared detector and/or a shunted blinded infrared detector. The floating blinded infrared detector may include an infrared detector coupled to and thermally isolated from the substrate; and a blocking structure disposed above the infrared detector to block external thermal radiation from being received by the infrared detector; and wherein the blocking structure comprises a plurality of openings. The shunted blinded infrared detector may include an additional infrared detector coupled to the substrate; an additional blocking structure disposed above the infrared detector to block external thermal radiation from being received by the additional infrared detector; and a material that thermally couples the additional infrared detector to the substrate and the additional blocking structure. Methods for using and forming the device are also disclosed.

First claim

The invention claimed is:

1. A device, comprising:
a substrate;
a floating blinded infrared detector comprising:
a first microbolometer suspended above and thermally isolated from the substrate; and
a first blocking structure coupled to the substrate, disposed at a distance from the first microbolometer, and configured to block at least a portion of external thermal radiation from being received by the first microbolometer,

wherein the first blocking structure comprises a staircase structure, and
wherein the first blocking structure comprises a plurality of openings disposed on one or more treads of the staircase structure; and
a shunted blinded infrared detector comprising:
a second microbolometer coupled to the substrate,
a second blocking structure coupled to the substrate, disposed at a distance from the second microbolometer, and configured to block external thermal radiation from being received by the second microbolometer, and
a material disposed beneath the second blocking structure that thermally couples the second microbolometer to the substrate and to the second blocking structure.

2. The device of claim 1 , further comprising an array of infrared detectors, coupled to and thermally isolated from the substrate, configured to receive external thermal radiation to capture infrared image data.

3. The device of claim 1 , further comprising a plurality of the shunted blinded infrared detectors and a plurality of the floating blinded infrared detectors.

4. The device of claim 1 , further comprising:
a logic device; and
an array of microbolometers, coupled to and thermally isolated from the substrate, configured to receive external thermal radiation to capture infrared image data, wherein:
the floating blinded infrared detector is configured to provide a detector reference signal;
the shunted blinded infrared detector is configured to provide a substrate reference signal; and
the logic device is configured to perform a temperature correction operation to the infrared image data based on the detector reference signal and the substrate reference signal.

5. The device of claim 1 , wherein the floating blinded infrared detector comprises a vacuum cavity separating the first microbolometer and the first blocking structure from the substrate.

6. The device of claim 5 , wherein the plurality of openings are configured to allow release materials to pass through the plurality of openings into the vacuum cavity.

7. The device of claim 5 , wherein the first microbolometer is thermally isolated from the first blocking structure by the vacuum cavity.

8. The device of claim 1 , wherein a size of each one of the plurality of openings is configured to prevent infrared radiation from passing through any one of the plurality of openings.

9. The device of claim 8 , wherein the size of each one of the plurality of openings is configured to prevent infrared radiation with wavelengths of less than 14 microns from passing through any one of the plurality of openings.

10. The device of claim 1 , wherein the first blocking structure further comprises a plurality of layers.

11. The device of claim 10 , wherein the plurality of layers comprises a first insulating layer, a metal layer, and a second insulating layer.

12. The device of claim 1 , wherein the substrate comprises a metal layer and a contact coupled to the metal layer, and wherein the first blocking structure is coupled to the contact.

13. The device of claim 1 , wherein the substrate comprises a metal layer and a plurality of contacts coupled to the metal layer, and wherein the first blocking structure and the second blocking structure are each coupled to one or more of the plurality of contacts.

14. The device of claim 13 , wherein at least one of the plurality of contacts is a basket-shaped contact or a stud contact.

15. A method of generating infrared images, the method comprising:
capturing infrared image data using at least one infrared detector in an array of infrared detectors disposed on a substrate, wherein the array of infrared detectors comprises at least one floating blinded infrared detector and at least one shunted blinded infrared detector, wherein the at least one floating blinded infrared detector comprises a first microbolometer, a first blocking structure configured to block at least a portion of external thermal radiation from being received by the first microbolometer, and a vacuum cavity separating the microbolometer from the substrate, and wherein the at least one shunted blinded infrared detector comprises a second microbolometer, a second blocking structure configured to block at least a portion of external thermal radiation from being received by the second microbolometer, and a material disposed beneath the second blocking structure that thermally couples the second microbolometer to the substrate and to the second blocking structure;
performing a first temperature correction to the infrared image data using detector reference data obtained, at least in part, from the at least one floating blinded infrared detector, wherein the detector reference data specifies a first temperature change due to heating from a current flowing through the first microbolometer; and
performing a second temperature correction to the infrared image data using substrate reference data obtained, at least in part, from the at least one shunted blinded infrared detector, wherein the substrate reference data specifies a second temperature change in the substrate.

16. A method of manufacturing a device, the method comprising:
providing a substrate;
forming a first microbolometer coupled to the substrate;
forming a first blocking structure coupled to the substrate and disposed above the microbolometer to block at least a portion of external infrared radiation from reaching the first microbolometer, wherein the blocking structure comprises a staircase structure and a plurality of openings disposed on one or more treads of the staircase structure;
forming a second microbolometer coupled to the substrate;
forming a second blocking structure coupled to the substrate, disposed above the second microbolometer, and configured to block at least a portion of external infrared radiation from reaching the second microbolometer; and
providing a material disposed beneath the second blocking structure that thermally couples the second microbolometer to the substrate and to the second blocking structure.

17. The method of claim 16 , wherein the forming the first blocking structure comprises:
depositing a sacrificial material over the first microbolometer and the substrate;
forming at least one insulating layer over the sacrificial material; and
forming a metal layer over the insulating layer.

18. The method of claim 17 , wherein the forming the first blocking structure further comprises forming the plurality of openings in the metal layer.

19. The method of claim 18 , further comprising:
removing at least part of the sacrificial material by passing release materials through the plurality of openings; and
creating a vacuum cavity defined, at least in part, by the substrate and the first blocking structure based on the removing of the sacrificial material.

20. The method of claim 16 , wherein each one of the plurality of openings has a size that is configured to prevent infrared radiation with wavelengths of less than 14 microns from passing through any one of the plurality of openings.

Assignees

• Flir Systems

Inventors

• Kurth Eric A
• Chan Chris
• Peters Kevin
• Franklin Patrick
• Cannata Robert F
• Dale James L
• Marx Tommy
• Howard David
• Rose Jefferson
• Debar Michael

Classifications

• G01M3/34

  by testing the possibility of maintaining the vacuum in containers, e.g. in can-testing machines · CPC title

• G01J2005/202

  Arrays · CPC title

• G01J5/20

  using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices · CPC title

• H01L27/14623

  Electricity · mapped topic

• G01L21/12

  measuring changes in electric resistance of measuring members, e.g. of filaments; Vacuum gauges of the Pirani type · CPC title