阅读说明：本技术 红外探测器及其制备方法 (Infrared detector and preparation method thereof ) 是由 黄勇 赵宇 吴启花 于 2018-06-22 设计创作，主要内容包括：本发明公开了一种红外探测器,包括：N型衬底；探测部,设置于所述N型衬底上,所述探测部包括多个叠层设置的探测单元；上电极,设置于所述探测部上；下电极,设置于所述N型衬底上。其中,所述探测单元包括N型接触层,以及依序叠层设置在所述N型接触层上的N型超晶格导电层、超晶格吸收层、P型超晶格导电层及P型接触层,相邻所述探测单元间形成隧道结。本发明还公开了一种红外探测器的制作方法。本发明的红外探测器通过多个探测单元对光子进行有效吸收,保证了量子效率且加工简单,减小了红外探测器的加工的难度,此外还有效降低了暗电流。(The invention discloses an infrared detector, comprising: an N-type substrate; a probe section provided on the N-type substrate, the probe section including a plurality of probe cells stacked one on another; an upper electrode disposed on the detection part; and the lower electrode is arranged on the N-type substrate. The detection units comprise N-type contact layers, and N-type superlattice conducting layers, superlattice absorption layers, P-type superlattice conducting layers and P-type contact layers which are sequentially stacked on the N-type contact layers, and tunnel junctions are formed between every two adjacent detection units. The invention also discloses a manufacturing method of the infrared detector. According to the infrared detector, photons are effectively absorbed by the plurality of detection units, so that the quantum efficiency is ensured, the processing is simple, the processing difficulty of the infrared detector is reduced, and in addition, the dark current is effectively reduced.)

1. An infrared detector, comprising:

an N-type substrate;

a probe section provided on the N-type substrate, the probe section including a plurality of probe cells stacked one on another; the detection units are of P-I-N type structures, and tunnel junctions are formed between every two adjacent detection units;

an upper electrode disposed on the detection part;

a lower electrode disposed on the N-type substrate;

when the infrared detector works, the detection unit absorbs infrared light signals to be detected and converts the infrared light signals to be detected into electric signals, and the electric signals are transmitted through the tunnel junction.

2. The infrared detector according to claim 1, wherein the detection unit includes an N-type contact layer, and an N-type superlattice conductive layer, a superlattice absorption layer, a P-type superlattice conductive layer, and a P-type contact layer stacked in sequence on the N-type contact layer; the P-type contact layer of the detection unit and the N-type contact layer of the adjacent detection unit form the tunnel junction.

3. The infrared detector as set forth in claim 2, wherein the superlattice absorption layer has a thickness of 100 to 500 nm.

4. The infrared detector as set forth in claim 2, wherein the material of the N-type superlattice conductive layer comprises an N-type InAs/GaSb superlattice material or an N-type InAs/InAsSb superlattice material;

and/or the material of the superlattice absorption layer comprises undoped InAs/GaSb superlattice material or undoped InAs/InAsSb superlattice material;

and/or the material of the P-type superlattice conducting layer comprises a P-type InAs/GaSb superlattice material or a P-type InAs/InAsSb superlattice material;

and/or the N-type substrate is an N-type GaSb substrate or an N-type InAs substrate;

and/or the N-type contact layer is an N-type InAs contact layer;

and/or the P-type contact layer is a P-type GaSb contact layer.

5. The infrared detector as claimed in any one of claims 1 to 4, characterized in that said detecting section comprises 2-100 of said detecting units.

6. A method for manufacturing an infrared detector according to any one of claims 1 to 5, characterized in that the method comprises:

s10, providing an N-type substrate;

s20, forming a plurality of detection units which are stacked on the N-type substrate to form a detection part; the detection units are of P-I-N type structures, and tunnel junctions are formed between every two adjacent detection units;

s30, forming an upper electrode on the detecting part;

and S40, forming a lower electrode on the N-type substrate.

7. The method of manufacturing according to claim 6, wherein the step S20 includes:

s21, manufacturing and forming an N-type contact layer;

s22, forming an N-type superlattice conducting layer on the N-type contact layer;

s23, forming a superlattice absorption layer on the N-type superlattice conducting layer;

s24, forming a P-type superlattice conducting layer on the superlattice absorption layer;

s25, forming a P-type contact layer on the P-type superlattice conducting layer;

s26, repeating the steps S21 to S25 at least once on the P-type contact layer; the P-type contact layer of the detection unit and the N-type contact layer of the adjacent detection unit form the tunnel junction.

8. The method according to claim 7, wherein the superlattice absorption layer has a thickness of 100 to 500 nm.

9. The method according to claim 6, wherein the step S20 is performed by a MOCVD (metal organic chemical vapor deposition) process or a molecular beam epitaxy process on the N-type substrate to form the probe portions.

10. The infrared detector according to any one of claims 6 to 9,

the material of the N-type superlattice conducting layer comprises an N-type InAs/GaSb superlattice material or an N-type InAs/InAsSb superlattice material;

and/or the material of the superlattice absorption layer comprises undoped InAs/GaSb superlattice material or undoped InAs/InAsSb superlattice material;

and/or the material of the P-type superlattice conducting layer comprises a P-type InAs/GaSb superlattice material or a P-type InAs/InAsSb superlattice material;

and/or the N-type substrate is an N-type GaSb substrate or an N-type InAs substrate;

and/or the N-type contact layer is an N-type InAs contact layer;

and/or the P-type contact layer is a P-type GaSb contact layer.

Technical Field

The invention belongs to the technical field of semiconductors, and particularly relates to an infrared detector and a preparation method thereof.

Background

Infrared radiation detection is an important component of infrared technology and is widely applied to the fields of thermal imaging, satellite remote sensing, gas monitoring, optical communication, spectral analysis and the like. The antimonide InAs/GaSb or InAs/InAsSb second-class superlattice infrared detector is considered to be one of the most ideal choices for preparing the third-generation infrared detector due to the characteristics of good uniformity, low Auger recombination rate, large wavelength adjusting range and the like. Compared with a mercury cadmium telluride infrared detector (HgCdTe), the mercury cadmium telluride infrared detector has better uniformity repeatability, lower cost and better performance in a very long wave band; compared with a quantum well infrared detector (QWIP), the quantum well infrared detector has the advantages of higher quantum efficiency, smaller dark current and simpler process.

Antimonide superlattice infrared detectors typically operate at low temperatures (e.g., 77K). If the operating temperature of the device can be increased, the power consumption of the refrigerator can be reduced, the size of the components can be reduced, the service life of the system can be prolonged, and the refrigerating time can be reduced. However, the increase in temperature generally results in an increase in the dark current, a decrease in the diffusion length, and a decrease in the quantum efficiency of the detector. In order to overcome the adverse factors, one of the prior art schemes is to use an antimonide-based interband cascade detector, which connects a plurality of InAs/GaSb superlattice absorption regions through an InAs/AlSb multistage chirped superlattice and a GaSb/AlSb tunneling region, and obtains a detection signal at a temperature of 350K. However, the detector uses an InAs/AlSb multi-stage chirped superlattice and a GaSb/AlSb tunneling region to help the transport of current carriers, and the InAs/AlSb multi-stage chirped superlattice and the GaSb/AlSb tunneling region are complex in forming process, so that the existing antimonide cascade type detector has certain difficulties in design, growth and processing, and the practicability of the device is influenced.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the infrared detector with simple design and better practicability and the preparation method thereof.

In order to achieve the purpose of the invention, the invention adopts the following technical scheme:

according to an aspect of the present invention, there is provided an infrared detector including:

an N-type substrate;

a probe section provided on the N-type substrate, the probe section including a plurality of probe cells stacked one on another; the detection units are of P-I-N type structures, and tunnel junctions are formed between every two adjacent detection units;

an upper electrode disposed on the detection part;

a lower electrode disposed on the N-type substrate;

when the infrared detector works, the detection unit absorbs infrared light signals to be detected and converts the infrared light signals to be detected into electric signals, and the electric signals are transmitted through the tunnel junction.

Furthermore, the detection unit comprises an N-type contact layer, and an N-type superlattice conducting layer, a superlattice absorption layer, a P-type superlattice conducting layer and a P-type contact layer which are sequentially stacked on the N-type contact layer; the P-type contact layer of the detection unit and the N-type contact layer of the adjacent detection unit form the tunnel junction.

Furthermore, the thickness of the superlattice absorption layer is 100-500 nm.

Further, the material of the N-type superlattice conducting layer comprises an N-type InAs/GaSb superlattice material or an N-type InAs/InAsSb superlattice material;

and/or the material of the superlattice absorption layer comprises undoped InAs/GaSb superlattice material or undoped InAs/InAsSb superlattice material;

and/or the material of the P-type superlattice conducting layer comprises a P-type InAs/GaSb superlattice material or a P-type InAs/InAsSb superlattice material;

and/or the N-type substrate is an N-type GaSb substrate or an N-type InAs substrate;

and/or the N-type contact layer is an N-type InAs contact layer;

and/or the P-type contact layer is a P-type GaSb contact layer.

Further, the detection part comprises 2-100 detection units.

According to another aspect of the present invention, there is also provided a manufacturing method of the infrared detector, the manufacturing method including:

s10, providing an N-type substrate;

s20, forming a plurality of detection units which are stacked on the N-type substrate to form a detection part; the detection units are of P-I-N type structures, and tunnel junctions are formed between every two adjacent detection units;

s30, forming an upper electrode on the detecting part;

and S40, forming a lower electrode on the N-type substrate.

Further, the step S20 includes:

s21, manufacturing and forming an N-type contact layer;

s22, forming an N-type superlattice conducting layer on the N-type contact layer;

s23, forming a superlattice absorption layer on the N-type superlattice conducting layer;

s24, forming a P-type superlattice conducting layer on the superlattice absorption layer;

s25, forming a P-type contact layer on the P-type superlattice conducting layer;

s26, repeating the steps S21 to S25 at least once on the P-type contact layer; the P-type contact layer of the detection unit and the N-type contact layer of the adjacent detection unit form the tunnel junction.

Furthermore, the thickness of the superlattice absorption layer is 100-500 nm.

Further, in step S20, the probe portion is formed on the N-type substrate by a metal organic chemical vapor deposition process or a molecular beam epitaxy process.

Further, the material of the N-type superlattice conducting layer comprises an N-type InAs/GaSb superlattice material or an N-type InAs/InAsSb superlattice material;

and/or the material of the superlattice absorption layer comprises undoped InAs/GaSb superlattice material or undoped InAs/InAsSb superlattice material;

and/or the material of the P-type superlattice conducting layer comprises a P-type InAs/GaSb superlattice material or a P-type InAs/InAsSb superlattice material;

and/or the N-type substrate is an N-type GaSb substrate or an N-type InAs substrate;

and/or the N-type contact layer is an N-type InAs contact layer;

and/or the P-type contact layer is a P-type GaSb contact layer.

The invention has the beneficial effects that:

(1) the detection part is effectively simplified, the detection part is designed to be formed by a plurality of detection units with P-I-N type structures, tunnel junctions are formed between adjacent detection units, photons are effectively absorbed and transmitted through the plurality of detection units, the quantum efficiency is ensured, the processing is simple, and the processing difficulty of the infrared detector is reduced;

(2) in addition, the invention effectively reduces the dark current by reducing the length of the absorption region of the detection unit.

Drawings

The above and other aspects, features and advantages of embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic structural diagram of an infrared detector according to a first embodiment of the present invention;

FIG. 2 is a flow chart of a method for fabricating an infrared detector according to a second embodiment of the invention;

fig. 3 is a flow chart of a two step S20 according to an embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided to explain the principles of the invention and its practical application to thereby enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. In the drawings, the shapes and sizes of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or similar elements.