Aluminum indium antimonide focal plane array

• US 8,552,479 B2
• Filed: 03/12/2010
• Issued: 10/08/2013
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Teledyne FLIR LLC (Teledyne Technologies Incorporated)
• Original Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Inventors: Bornfreund, Richard E., Barton, Jeffrey B.
• Primary Examiner(s): GEBREMARIAM, SAMUEL A
• Application Number:
  US12/723,374
• Publication Number:
  US 20110221024A1
• Time in Patent Office: 1,306 Days
• Field of Search: 257290-292, 257/E31.084, 250/370.13, 250/370.06
• US Class Current: 257/290
• CPC Class Codes: H01L 31/03046 including ternary or quaternary compounds, e.g. GaAlAs, InGaAs, InGaAsP
• CPC Class Codes: H01L 31/1035 the devices comprising active layers formed only by AIIIBV compounds
• CPC Class Codes: H01L 31/1844 comprising ternary or quaternary compounds, e.g. Ga Al As, In Ga As P
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

In one embodiment, a detector includes an Al_xIn_(1-x)Sb absorber layer, and an Al_yIn_(1-y)Sb passivation layer disposed above the Al_xIn_(1-x)Sb absorber layer, wherein x<y. The detector further includes a junction formed in a region of the Al_xIn_(1-x)Sb absorber layer, and a metal contact disposed above the junction and through the Al_yIn_(1-y)Sb passivation layer.

Claims

1. A detector comprising:

an Al_xIn_(1-x)Sb absorber layer;

an Al_yIn_(1-y)Sb passivation layer disposed above the Al_xIn_(1-x)Sb absorber layer, wherein x<

y and x is nonzero;

a junction formed in a region of the Al_xIn_(1-x)Sb absorber layer; and

a metal contact disposed above the junction and through the Al_yIn_(1-y)Sb passivation layer.

2. The detector of claim 1, wherein the Al_xIn_(1-x)Sb absorber layer and the Al_yIn_(1-y)Sb passivation layer are each epitaxial layers formed consecutively during one growth run to substantially eliminate defects and/or contaminates disposed between the Al_xIn_(1-x)Sb absorber layer and the Al_yIn_(1-y)Sb passivation layer.

3. The detector of claim 1, wherein x is between about 0.01 and about 0.1, and y is between about 0.02 and about 0.13.

4. The detector of claim 1, wherein the Al_xIn_(1-x)Sb absorber layer has a thickness between about 30,000 angstroms and about 150,000 angstroms and the Al_yIn_(1-y)Sb passivation layer has a thickness between about 100 angstroms and about 10,000 angstroms.

5. The detector of claim 1, wherein the junction is selected from the group consisting of a p-n junction, an n-p junction, a p-i-n junction, and a n-i-p junction.

6. The detector of claim 1, comprising:

an overglass layer disposed above the Al_yIn_(1-y)Sb passivation layer; and

an indium bump disposed above the metal contact and the overglass layer.

7. The detector of claim 1, comprising:

an antireflective layer disposed below the Al_xIn_(1-x)Sb absorber layer.

8. The detector of claim 1, comprising:

an InSb substrate above which the Al_xIn_(1-x)Sb absorber layer is formed, wherein the InSb substrate is afterwards removed to expose a back surface of the Al_xIn_(1-x)Sb absorber layer.

9. An infrared sensor array comprising:

a two-dimensional array of detectors, each of the detectors comprising;

an Al_xIn_(1-x)Sb absorber layer;

an Al_yIn_(1-y)Sb passivation layer disposed above the Al_xIn_(1-x)Sb absorber layer, wherein x<

y;

a junction formed in a region of the Al_xIn_(1-x)Sb absorber layer;

a metal contact disposed above the junction and through the Al_yIn_(1-y)Sb passivation layer;

an overglass layer disposed above the metal contact; and

a bump contact disposed above the metal contact and through the overglass layer.

10. The sensor array of claim 9, wherein the Al_xIn_(1-x)Sb absorber layer and the Al_yIn_(1-y)Sb passivation layer are each epitaxial layers formed consecutively during one growth run.

11. The sensor array of claim 9, wherein x is between about 0.01 and about 0.1, and y is between about 0.02 and about 0.13.

12. The sensor array of claim 9, comprising:

an antireflective layer disposed below the Al_xIn_(1-x)Sb absorber layer.

13. The sensor array of claim 9, comprising:

an InSb substrate above which the Al_xIn_(1-x)Sb absorber layer is formed, wherein the InSb substrate is afterwards removed to expose a back surface of the Al_xIn_(1-x)Sb absorber layer.

14. A method of fabricating a detector, the method comprising:

providing an InSb substrate;

forming, by epitaxial growth in one growth run, an Al_xIn_(1-x)Sb absorber layer above a surface of the InSb substrate and an Al_yIn_(1-y)Sb passivation layer above the Al_xIn_(1-x)Sb absorber layer, wherein x<

y and x is nonzero;

forming a junction in a region of the Al_xIn_(1-x)Sb absorber layer;

forming a metal contact above the junction and through the Al_yIn_(1-y)Sb passivation layer; and

removing the InSb substrate to expose the Al_xIn_(1-x)Sb absorber layer.

15. The method of claim 14, wherein the Al_xIn_(1-x)Sb absorber layer and the Al_yIn_(1-y)Sb passivation layer are each formed by one of molecular beam epitaxy (MBE) or metal-organic condensed vapor deposition (MOCVD).

16. The method of claim 14, wherein x is between about 0.01 and about 0.1, and y is between about 0.02 and about 0.13.

17. The method of claim 14, wherein the Al_xIn_(1-x)Sb absorber layer is formed to a thickness between about 30,000 angstroms and about 150,000 angstroms and the Al_yIn_(1-y)Sb passivation layer is formed to a thickness between about 100 angstroms and about 10,000 angstroms.

18. The method of claim 14, wherein the InSb substrate is removed by one of lapping, diamond point turning, chemical etching, and combinations thereof.

19. The method of claim 14, wherein forming the junction includes forming one of a p-n junction, an n-p junction, a p-i-n junction, or a n-i-p junction.

20. The method of claim 14, comprising:

forming an antireflective layer over the exposed Al_xIn_(1-x)Sb absorber layer.