Monolithic lead-salt infrared radiation detectors and methods of formation

• US 6,734,516 B2
• Filed: 10/11/2001
• Issued: 05/11/2004
• Est. Priority Date: 10/13/2000
• Status: Expired due to Fees

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Litton Systems Incorporated
• Inventors: Jacksen, Niels F., Tibbitt, Jeffrey G., Sepulveda, Michael A.
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): Wilson, Scott R.
• Application Number:
  US09/976,723
• Publication Number:
  US 20020058352A1
• Time in Patent Office: 943 Days
• Field of Search: 257/108, 257/428, 257/431-466, 438/56
• US Class Current: 257/431
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H01L 27/14683 Processes or apparatus peculiar to the manufacture or treatment of these devices or parts thereof not peculiar thereto H01L21/00
• CPC Class Codes: H01L 31/0324 comprising only AIVBVI or AIIBIVCVI chalcogenide compounds, e.g. Pb Sn Te

Abstract

A hybridized Lead-Salt infrared radiation detector includes a focal plane having a substrate and a sensitized, delineated Lead-Salt layer upon the substrate, the delineations forming a plurality of sections in a two-dimensional array. The detector also includes electrical contacts for each of the sections and a common grid between the sections. The detector further includes a layer of conductive barrier material on each electrical contact, a layer of passivating material on each section, and a layer of fusible conductive material on each layer of conductive barrier material.

Claims

1. A two-dimensional array of Lead-Salt detector elements monolithically formed on an integrated circuit, the system comprising:

an integrated circuit comprising a passivation layer and a plurality of electrical contacts, the passivation layer having vias to the electrical contacts;

a Lead-Salt layer deposited upon the passivation layer, wherein sensitized, delineations are formed to provide a plurality of detector elements; and

electrical couplers formed between the electrical contacts and the detector elements.

2. The system of claim 1, wherein the passivation layer comprises Silicon Dioxide.

3. The system of claim 1, wherein the electrical couplers comprise Gold.

4. The system of claim 1, wherein the pitch of the detector elements is less than approximately thirty microns.

5. The system of claim 1, further comprising a conductive material upon the passivation layer and underlying part of the Lead-Salt layer, the conductive material forming a plurality of detector element contacts and a common grid for the detector elements, wherein the electrical couplers between the electrical contacts and the detector elements comprise electrical couplers between the electrical contacts and the detector element contacts.

6. The system of claim 5, wherein the conductive material comprises Titanium-Gold.

7. The system of claim 5, wherein the electrical couplers overlay at least part of the detector element contacts.

8. The system of claim 5, wherein the electrical couplers overlay at least part of the detector element contacts and the detector elements.

9. The system of claim 1, wherein the electrical couplers overlay at least part of the detector elements.

10. The system of claim 1, wherein the Lead-Salt comprises Lead Selenide.

13. The system of claim 1, further comprising a passivation layer over the Lead-Salt layer.

11. A two-dimensional array of Lead-Salt detector elements monolithically formed on an integrated circuit, the system comprising:

an integrated circuit comprising a texturized passivation layer and a plurality of electrical contacts, the passivation layer having vias to the electrical contacts;

a delineated sensitized Lead-Salt layer formed upon the passivation layer, the delineations forming a plurality of detector elements; and

electrical couplers formed between the electrical contacts and the detector elements.

12. A two-dimensional array of Lead-Salt detector elements monolithically formed on an integrated circuit, the system comprising:

an integrated circuit comprising a passivation layer and a plurality of electrical contacts, the passivation layer having vias to the electrical contacts;

a textured coating upon the passivation layer;

a delineated, sensitized Lead-Salt layer formed upon the texturized coating, the delineations forming a plurality of detector elements; and

electrical couplers formed between the electrical contacts and the detector elements.

14. A two-dimensional array of Lead-Salt detector elements monolithically mounted on an integrated circuit, the system comprising:

an integrated circuit comprising a passivation layer covering a plurality of electrical contacts, the passivation layer having vias to the electrical contacts;

a conductive material upon the passivation layer, the conductive material forming a plurality of detector element contacts and a common grid for the detector;

a delineated, sensitized Lead-Sulfide layer formed upon the passivation layer and part of the conductive material, the delineations forming a plurality of detector elements having a pitch of less than approximately thirty microns; and

electrical couplers formed between the electrical contacts and the detector element contacts.

15. The system of claim 14, wherein the electrical couplers overlay the detector element contacts and the detector elements.

16. A two-dimensional array of Lead-Salt detector elements monolithically mounted on an integrated circuit, the system comprising:

an integrated circuit comprising a passivation layer covering a plurality of electrical contacts, the passivation layer having vias to the electrical contacts;

a textured coating upon the passivation layer;

a delineated, sensitized Lead-Selenide layer formed upon the textured coating, the delineations forming a plurality of detector elements having a pitch of less than approximately thirty microns; and

electrical couplers formed between the electrical contacts and the detector elements.

17. An infrared sensor comprising:

optics; and

a two-dimensional array of Lead-Salt detector elements monolithically formed on an integrated circuit, the system comprising;

an integrated circuit comprising a passivation layer and a plurality of electrical contacts, the passivation layer having vias to the electrical contacts;

a Lead-Salt layer deposited upon the passivation layer, wherein sensitized, delineations are formed to provide a plurality of detector elements; and

electrical couplers between the electrical contacts and the detector elements.