Infrared detector pixel structure and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-11034577-B2
Application number	US-201616310821-A
Country	US
Kind code	B2
Filing date	Sep 8, 2016
Priority date	Jul 28, 2016
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

The present invention provides an infrared detector pixel structure and manufacturing method thereof. The structure comprises a conductive metal region on surface of the silicon substrate; an infrared detecting element located above the silicon substrate for detecting infrared light and generating electrical signal; and a conductive beam unit electrically connected to the infrared detecting element for transmitting the electrical signal to the conductive metal region; the conductive beam unit includes at least one conductive beam layer and multilayer conductive trench arranged in a vertical direction; two ends of the conductive beam are respectively in contact with two layers of conductive trenches whose bottom portions are not in the same horizontal plane; the infrared detecting element is in contact with one conductive trench one conductive beam; the conductive metal region is in contact with bottom portion of the other layer of conductive trench therein; the electrical signal is transmitted along the height direction of the conductive trench and the conductive beam, so as to be transmitted downward to the conductive metal region in a circuitous path in the vertical direction.

First claim

The invention claimed is:

1. An infrared detector pixel structure, which is located on a silicon substrate, comprising a conductive metal region on surface of the silicon substrate; an infrared detecting element located above the silicon substrate for detecting infrared light and generating electrical signal; and a conductive beam unit electrically connected to the infrared detecting element for transmitting the electrical signal generated by the infrared detecting element to the conductive metal region; wherein the conductive beam unit includes at least one conductive beam layer multiple conductive trenches, and optionally an infrared-connected conductive beam layer, the conductive trenches are arranged in a vertical direction; wherein
two ends of each conductive beam layer are respectively connected to two conductive trenches, wherein bottom portions of the conductive trenches are not in the same horizontal plane;
when the conductive beam unit includes the infrared-connected conductive beam layer, the infrared detecting element is in contact with the infrared-connected conducive beam layer, and only one end of the infrared-connected conductive beam layer is connected to one of the conductive trenches, when the conductive beam unit does not include the infrared-connected conductive beam layer the infrared detecting elements is in contact with one of the conductive trenches;
the conductive metal region is in contact with a bottom portion of another one of the conductive trenches;
the electrical signal generated by the infrared detecting element is transmitted along the conductive trenches and the at least one conductive beam layer, and optionally along the infrared-connected conductive beam layer to be transmitted downward to the conductive metal region in a circuitous path in the vertical direction.

2. The infrared detector pixel structure according to claim 1 , wherein, the conductive beam unit includes one conductive beam layer and two conductive; the two conductive trenches include a first conductive trench of which a bottom portion is in contact with the conductive metal region and a top portion is located at the conductive beam layer and a second conductive trench of which a bottom portion is higher than that of the first conductive trench and a top portion is located at the conductive beam layer; the top portion of the first conductive trench and the top portion of the second conductive trench are respectively connected to two ends of the conductive beam layer; the bottom portion of the second conductive trench is connected to the infrared detecting element; the electrical signal generated by the infrared detecting element is firstly transmitted to the top portion of the second conductive trench via the bottom portion of the second conductive trench, next transmitted to the top portion of the first conductive trench via the conductive beam layer, then transmitted to the bottom portion of the first conductive trench from the top portion of the first conductive trench and thus transmitted to the conductive metal region; and further transmitted to an interconnection layer via the conductive metal region.

3. The infrared detector pixel structure according to claim 1 , wherein, each conductive beam layer has a first end connected to a bottom portion of one of the conductive trenches and a second end connected to a top portion of another one of the conductive trenches the conductive trenches comprise a top conductive trench, a top portion of the top conductive trench is connected to the infrared detecting element such that the infrared detecting element is located above the conductive beam unit, and each pair of one of the conductive trenches and one of the at least one conductive beam layer constitute a structure with a circuitous stepwise shape such that a transmission path of the electrical signal generated by the infrared detecting element is a circuitous stepwise shape; the electrical signal generated by the infrared detecting element is transmitted from the top portion of the top conductive trench to a bottom portion of the top conductive trench, then transmitted to the top portion of a next conductive trench via the conductive beam layer, and finally transmitted to the conductive metal region.

4. The infrared detector pixel structure according to claim 1 , wherein, the conductive beam unit includes the infrared-connected conductive beam layer; each conductive beam layer has a first end connected to a bottom portion of one of the conductive trenches and a second end connected to a top portion of another one of the conductive trenches; wherein the conductive trenches include a top conductive trench and a bottom conductive trench; a bottom portion of the bottom conductive trench is in contact with the conductive metal region; a top portion of the top conductive trench is in contact with the infrared-connected conductive beam layer, the infrared-connected conductive beam layer is connected to the infrared detecting element such that a micro-bridge structure is located above the conductive beam unit, and each pair of one of the conductive trenches and one of the at least one conductive beam layer constitute a structure with a circuitous stepwise shape such that a transmission path of electrical signal generated by the micro-bridge structure is a circuitous stepwise shape; the electrical signal generated by the infrared detecting element is transmitted from the infrared-connected conductive beam layer to a top portion of the top conductive trench, then transmitted to a bottom portion of the top conductive trench, and finally transmitted to the conductive metal region.

5. The infrared detector pixel structure according to claim 1 , wherein, the conductive beam layer is constituted by a first conductive layer and a first upper release protection layer and a first lower release protection layer surrounding the first conductive layer; each of the conductive trenches is constituted by a second upper release protection layer, a second lower release protection layer, and a second conductive layer between the second upper release protection layer and the second lower release protection layer.

6. The infrared detector pixel structure according to claim 1 , wherein, the conductive beam layer is constituted by a first conductive layer and a first release protection layer on an upper surface of the first conductive layer; each of the conductive trenches is constituted by a second conductive layer and a second upper release protection layer on the second conductive layer.

7. The infrared detector pixel structure according to claim 1 , wherein, the conductive beam layer is constituted by a first conductive layer;
each of the conductive trenches is constituted by a second conductive layer.

8. The infrared detector pixel structure according to claim 7 , wherein, each of the conductive trenches is fully filled with the second conductive layer.

9. The infrared detector pixel structure according to claim 1 , wherein, a bottom portion of the conductive beam layer has protrusions.

10. The infrared detector pixel structure according to claim 9 , wherein, the protrusions are located at non-center positions of the conductive beam layer.

11. The infrared detector pixel structure according to claim 9 , wherein, the protrusions are located at equipartitions of the conductive beam layer.

12. The infrared detector pixel structure according to claim 9 , wherein, the protrusions and the conductive beam layer both are groove.

13. The infrared detector pixel structure according to claim 9 , wherein, the protrusions are reverse hemisphere or reverse cone.

14. The infrared detector pixel

Assignees

• Shanghai Ic R&D Ct Co Ltd

Inventors

• Kang Xiaoxu

Classifications

• G01J5/20 Primary

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

• B81C1/00

  Manufacture or treatment of devices or systems in or on a substrate (B81C3/00 takes precedence) · CPC title

• B81B7/00

  Microstructural systems {; Auxiliary parts of microstructural devices or systems} · CPC title

• B81C2201/01

  in or on a substrate · CPC title

• G01J5/24

  Use of specially adapted circuits, e.g. bridge circuits · CPC title