Barrier infrared detector architecture for focal plane arrays

Patent metadata

Field	Value
Publication number	US-12300712-B2
Application number	US-202217938838-A
Country	US
Kind code	B2
Filing date	Oct 7, 2022
Priority date	Oct 7, 2021
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

Disclosed herein is an infrared detector. The detector includes a plurality of pixels. Each pixel includes an n-type semiconductor top contact layer, a p-type semiconductor layer electrically connected to the n-type top contact layer to form a top p-n junction, a unipolar electron barrier electrically connected to the p-type semiconductor layer, a bottom absorber, and an n-type semiconductor bottom contact layer electrically connected to the bottom absorber. The unipolar electron barrier is positioned between the p-type semiconductor layer and the bottom absorber.

First claim

What is claimed is:

1. An infrared detector array comprising:
a plurality of pixels, wherein each pixel comprises:
an n-type semiconductor top contact layer;
a p-type semiconductor layer electrically connected to the n-type semiconductor top contact layer to form a top p-n junction;
a unipolar electron barrier electrically connected to the p-type semiconductor layer;
a bottom absorber, wherein the unipolar electron barrier is positioned between the p-type semiconductor layer and the bottom absorber; and
an n-type semiconductor bottom contact layer electrically connected to the bottom absorber.

2. The infrared detector array of claim 1 , wherein the bottom absorber comprises a p-type semiconductor absorber layer.

3. The infrared detector array of claim 2 , wherein the bottom absorber further comprises a n-type semiconductor absorber layer which forms a p-n junction with the p-type semiconductor absorber layer.

4. The infrared detector array of claim 2 , further comprising a window layer which is positioned between the p-type semiconductor absorber layer and the n-type semiconductor bottom contact layer.

5. The infrared detector array of claim 4 , wherein the window layer comprising an n-type semiconductor window layer.

6. The infrared detector array of claim 5 , wherein the window layer further comprises a p-type semiconductor window layer which forms a p-n junction with the n-type semiconductor window layer.

7. The infrared detector array of claim 1 , wherein a first p-type transition layer is positioned between the p-type semiconductor layer and the unipolar electron barrier.

8. The infrared detector array of claim 7 , wherein a second p-type transition layer is positioned between the unipolar electron barrier and the bottom absorber.

9. The infrared detector array of claim 1 , wherein each n-type semiconductor top contact layer and p-type semiconductor layer are physically separated from each other.

10. The infrared detector array of claim 9 , wherein each unipolar electron barrier are physically separated from each other.

11. The infrared detector array of claim 10 , wherein each bottom absorber comprises a monolithic p-type absorber semiconductor layer.

12. The infrared detector array of claim 11 , wherein the monolithic p-type absorber semiconductor layer comprises a plurality of cavities which do not extend beyond the monolithic p-type absorber semiconductor layer.

13. The infrared detector array of claim 12 , wherein the plurality of cavities overlap with gaps between each n-type semiconductor top contact layer and p-type semiconductor layer.

14. The infrared detector array of claim 9 , wherein each unipolar electron barrier combined to form a monolithic layer.

15. The infrared detector array of claim 14 , wherein the monolithic layer comprises a plurality of cavities which do not extend beyond the monolithic layer.

16. The infrared detector array of claim 15 , wherein the plurality of cavities overlap gaps between each n-type semiconductor top contact layer and p-type semiconductor layer.

17. The infrared detector array of claim 1 , wherein the p-type semiconductor layer comprises a recombination layer and wherein the top p-n junction electrically isolates each pixel from adjacent pixels.

18. The infrared detector array of claim 17 , wherein the absorber layer has a bandgap which is narrower than the recombination layer.

19. The infrared detector array of claim 17 , wherein the recombination layer comprises a thickness of 1 micron or less.

20. A focal plane array comprising:
the infrared detector array of claim 1 ; and
a silicon readout integrated circuit electrically connected to the infrared detector array.

Assignees

• California Inst Of Techn

Inventors

• Ting David Z
• Keo Sam A
• Khoshakhlagh Arezou
• Soibel Alexander
• Gunapala Sarath D

Classifications

• H10F39/1847 Primary

  Multispectral infrared image sensors having a stacked structure, e.g. NPN, NPNPN or multiple quantum well [MQW] structures · CPC title

• H01L27/14652 Primary

  Electricity · mapped topic