Planar thermal array

• US 7,170,059 B2
• Filed: 10/03/2003
• Issued: 01/30/2007
• Est. Priority Date: 10/03/2003
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Cole, Barrett E., Wood, Roland A., Higashi, Robert E.
• Primary Examiner(s): Luebke; Renee
• Assistant Examiner(s): ZETTL, MARY E
• Application Number:
  US10/678,527
• Publication Number:
  US 20050072924A1
• Time in Patent Office: 1,215 Days
• Field of Search: 250/338.1, 250/338.4, 250/370.09, 250/370.08, 438/73
• US Class Current: 250/338.1
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01L 27/14649 Infrared imagers

Abstract

A thermal sensor structure having one level for an infrared detecting pixel including the sensor associated electronics. The electronics displace a small area thereby having little effect on the fill area of the pixel relative to a level having no pixel electronics. That level has thermally isolation for the substrate through the limited structural attachment to the substrate because of the access vias to the silicon. It has additional isolation because of a pit of removed silicon from the substrate below that one level. The thermal sensor may have an array with a large number of pixels having the one level for the pixels and electronics structure.

Claims

1. A sensor comprising:

a substrate;

a pixel situated on a single level on the substrate; and

an electronics circuit situated on the single level, wherein the pixel has a fill factor greater than 69 percent.

2. The sensor of claim 1, wherein the pixel is an infrared light detector.

3. The sensor of claim 2, wherein the substrate has a pit proximate to the pixel.

4. The sensor of claim 3, wherein the pixel has at least one via in the one level supporting the pixel.

5. The sensor of claim 4, wherein the electronics circuit comprises a FET circuit.

6. The sensor of claim 5, wherein the electronics circuit comprises at least one small area FET, leaving a significant portion of the substrate free of circuits.

7. The sensor of claim 6, wherein the electronics is CMOS circuitry.

8. The sensor of claim 7, wherein the pixel is a microbolometer.

9. The sensor of claim 4, wherein the electronics comprises a bipolar transistor circuit.

10. A thermal sensor comprising:

a substrate; and

an array of pixels situated on the substrate; and

wherein;

each pixel is located on a single level;

an electronic circuit is associated with each pixel;

each electronic circuit is located on the single level with the pixel; and

the pixels have a fill factor greater than 69 percent.

11. The sensor of claim 10, wherein each pixel is an infrared light detector.

12. The sensor of claim 11, wherein each pixel is suspended over a pit in the substrate.

13. The sensor of claim 12, wherein each electronic circuit is CMOS FET circuitry.

14. The sensor of claim 13, wherein each pixel is a microbolometer.

15. A sensing means comprising:

means for sensing infrared light;

means for electronically processing signals related to infrared light sensed by the means for sensing infrared light; and

means for supporting on one level the means for sensing infrared light and the means for electronically processing signals, wherein the means for electronically processing signals has an area that is significantly smaller than the area of the means for sensing infrared light.

16. The means of claim 15, wherein the means for supporting on one level supports the means for sensing infrared light over a thermal isolating opening.

17. The means of claim 16, wherein the means for sensing infrared light is an array of pixels.

18. The means of claim 17, wherein:

each pixel of the array of pixels is a microbolometer pixel comprising VO_x; and

the means for electronically processing signals is small area transistor circuitry that leaves a significant portion of the means for supporting free of circuits.

19. The means of claim 18, wherein the small area transistor circuitry is CMOS FET circuitry.

20. The means of claim 19, wherein:

the means for supporting on one level is a planar level substrate; and

the thermal isolating opening is a pit in the substrate under each pixel of the array of pixels.

21. A sensor comprising:

a substrate;

a pixel situated in a first plane relative to a surface of the substrate; and

an electronics circuit situated in the first plane;

wherein the pixel has a fill factor greater than 69 percent.

22. A thermal sensor comprising:

a substrate; and

an array of pixels situated on the substrate; and

wherein;

each pixel is located on a first surface;

an electronic circuit is associated with each pixel;

each electronic circuit is located on the first surface proximate to the pixel; and

each pixel has a fill factor greater than 69 percent.

23. A thermal sensor comprising:

a substrate; and

an array of pixels situated on the substrate; and

wherein;

an electronic circuit is associated with each pixel; and

each electronic circuit is situated horizontally proximate to the pixel;

wherein the pixels have a fill factor greater than 69 percent.

24. A thermal sensor comprising:

a substrate; and

an array of pixels situated on the substrate; and

electronics situated on the substrate horizontally proximate to the array of pixels;

wherein each pixel has a fill factor greater than 69 percent.

25. A sensing means comprising:

means for sensing infrared light;

means for electronically processing signals related to infrared light sensed by the means for sensing infrared light; and

means for supporting on one surface the means for sensing infrared light and the means for electronically processing signals;

wherein the means for electronically processing signals has an area that is significantly smaller than the area of the means for sensing infrared light.

26. A sensing means comprising:

means for sensing infrared light;

means for electronically processing signals related to infrared light sensed by the means for sensing infrared light; and

means for supporting the means for sensing infrared light and the means for electronically processing signals horizontally proximate to each other;

wherein the means for electronically processing signals has an area that is significantly smaller than the area of the means for sensing infrared light.

27. A sensing means comprising:

means for sensing infrared light;

means for electronically processing signals related to infrared light sensed by the means for sensing infrared light; and

means for supporting in a plane the means for sensing infrared light and the means for electronically processing signals;

wherein the means for electronically processing signals has an area that is significantly smaller than the area of the means for sensing infrared light.