阅读说明：本技术 多色红外探测器及其制作方法 (Multicolor infrared detector and manufacturing method thereof ) 是由 黄勇 赵宇 吴启花 熊敏 于 2019-04-08 设计创作，主要内容包括：本发明公开了一种多色红外探测器,包括n型衬底以及依序层叠设置于n型衬底上的第一n型接触层、n型蓝色通道吸收层、p型空穴势垒层、p型绿色通道吸收层、n型电子势垒层、n型红色通道吸收层和第二n型接触层,第一n型接触层上还设有第一电极,第二n型接触层上设有与第一电极对应的第二电极,其中,n型蓝色通道吸收层、p型空穴势垒层和p型绿色通道吸收层的导带相互平齐,p型绿色通道吸收层、n型电子势垒层和n型红色通道吸收层的价带相互平齐。本发明还公开了上述探测器的制作方法。本发明解决了现有红外探测器的吸收波段较少的问题。(The invention discloses a multicolor infrared detector, which comprises an n-type substrate, and a first n-type contact layer, an n-type blue channel absorption layer, a p-type hole barrier layer, a p-type green channel absorption layer, an n-type electron barrier layer, an n-type red channel absorption layer and a second n-type contact layer which are sequentially stacked on the n-type substrate, wherein a first electrode is further arranged on the first n-type contact layer, and a second electrode corresponding to the first electrode is arranged on the second n-type contact layer, wherein conduction bands of the n-type blue channel absorption layer, the p-type hole barrier layer and the p-type green channel absorption layer are mutually flush, and valence bands of the p-type green channel absorption layer, the n-type electron barrier layer and the n-type red channel absorption layer are mutually flush. The invention also discloses a manufacturing method of the detector. The invention solves the problem that the existing infrared detector has less absorption wave band.)

1. The multicolor infrared detector is characterized by comprising an n-type substrate (1), and a first n-type contact layer (2), an n-type blue channel absorption layer (3), a p-type hole barrier layer (4), a p-type green channel absorption layer (5), an n-type electronic barrier layer (6), an n-type red channel absorption layer (7) and a second n-type contact layer (8) which are sequentially stacked on the n-type substrate (1), wherein a first electrode (9) is further arranged on the first n-type contact layer (2), a second electrode (10) corresponding to the first electrode (9) is arranged on the second n-type contact layer (8), the conduction bands of the n-type blue channel absorption layer (3), the p-type hole barrier layer (4) and the p-type green channel absorption layer (5) are flush with each other, and the p-type green channel absorption layer (5), The valence bands of the n-type electronic barrier layer (6) and the n-type red channel absorption layer (7) are flush with each other.

2. The multicolor infrared detector according to claim 1, characterized in that the effective bandwidths of the p-type hole barrier layer (4), the n-type blue-channel absorption layer (3) and the p-type green-channel absorption layer (5) decrease in order.

3. The multicolor infrared detector according to claim 1, characterized in that the effective bandwidths of the n-type electron barrier layer (6), the p-type green-channel absorption layer (5) and the n-type red-channel absorption layer (7) decrease in order.

4. A polychromatic infrared detector according to any of claims 1-3, characterized in that the material of the first n-type contact layer (2), the n-type blue channel absorption layer (3), the n-type electron barrier layer (6), the n-type red channel absorption layer (7) and the second n-type contact layer (8) is a Si-doped n-type InAs/GaSb superlattice and/or an InAs/InAsSb superlattice.

5. The polychromatic infrared detector according to claim 4, wherein the material of the p-type hole barrier layer (4) is a p-type InAs/AlSb superlattice or InAsP/InAsSb superlattice doped with Zn or Be.

6. A multicolor infrared detector according to claim 4, characterized in that the material of said p-type green channel absorption layer (5) is a Zn or Be doped p-type InAs/GaSb superlattice or InAs/InAsSb superlattice.

7. The multicolor infrared detector according to claim 4, characterized in that the material of said n-type substrate (1) is n-type GaSb or InAs.

8. A method of making a multi-color infrared detector, the method comprising:

sequentially laminating a first n-type contact layer (2), an n-type blue channel absorption layer (3), a p-type hole barrier layer (4), a p-type green channel absorption layer (5), an n-type electron barrier layer (6), an n-type red channel absorption layer (7) and a second n-type contact layer (8) on an n-type substrate (1);

locally etching the second n-type contact layer (8), the n-type red channel absorption layer (7), the n-type electron barrier layer (6), the p-type green channel absorption layer (5), the p-type hole barrier layer (4) and the n-type blue channel absorption layer (3) to expose the first n-type contact layer (2) to form a detector mesa structure (A);

a first electrode (9) is formed on the first n-type contact layer (2), and a second electrode (10) is formed on the second n-type contact layer (8).

9. The fabrication method according to claim 8, wherein conduction bands of the n-type blue channel absorber layer (3), the p-type hole barrier layer (4) and the p-type green channel absorber layer (5) are flush with each other, and valence bands of the p-type green channel absorber layer (5), the n-type electron barrier layer (6) and the n-type red channel absorber layer (7) are flush with each other.

10. The method of manufacturing according to claim 9, wherein the effective bandwidths of the p-type hole barrier layer (4), the n-type blue channel absorber layer (3) and the p-type green channel absorber layer (5) decrease sequentially; and/or the effective bandwidths of the n-type electron barrier layer (6), the p-type green channel absorber layer (5), and the n-type red channel absorber layer (7) decrease in order.

Technical Field

The invention relates to the field of semiconductors, in particular to a multicolor infrared detector and a manufacturing 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 second-class superlattice (InAs/GaSb or InAs/InAsSb) 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 long-wavelength and very-long-wavelength 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. At present, the antimonide second-class superlattice infrared detectors are already industrialized.

One of the major features of the third generation infrared detection systems is the ability to detect two colors or even multiple colors. Compared with the traditional monochromatic detection, the multicolor infrared detector can provide information of a plurality of infrared bands at the same time, can obtain the absolute temperature of a target, inhibit background interference, increase the detection and identification distance, reduce the false alarm rate, and obviously improve the performance of the system and the universality on various weapon platforms. For a two-color infrared detector, two PN junctions are generally placed back to back, each PN junction corresponds to an absorption band, a band with a shorter wavelength is generally called a blue channel and is placed closer to the incident light direction, and a band with a longer wavelength is generally called a red channel and is placed behind the blue channel. And a green channel is added between the blue channel and the red channel by the three-color detector. Three color detection is reported in mercury cadmium telluride detectors, but is almost blank in antimonide class two superlattice detectors. The only report is an antimonide short/medium tristimulus detector based on P-type absorption region and hole barrier layer proposed by the university of northwest in 2017 (a. haddadi et al, Optics letters 42,4275,2017), whose band structure is shown in fig. 1, where P-type Red channel is represented by P-Red, P-type Green channel by P-Green, P-type Blue channel by P-Blue, and hole barrier layer by B. The device works in a Red channel P-Red under positive bias, works in a Green channel P-Green under zero bias, and works in a Blue channel P-Blue under negative bias. But because no potential barrier exists between the P-Green and the P-Blue and the P-Green and the P-Blue are both made of P-type materials, the crosstalk between the two channels is large; moreover, the device performance of the blue channel is not optimal with respect to a monochromatic detector of the same wavelength band, since there is no barrier. Therefore, there is a need to develop a better antimonide superlattice three-color infrared detector, which adopts a completely new structure, enables each wave band to work under the optimal condition, and realizes three-color detection through simple bias selection.

Disclosure of Invention

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

a multicolor infrared detector comprises an n-type substrate, and a first n-type contact layer, an n-type blue channel absorption layer, a p-type hole barrier layer, a p-type green channel absorption layer, an n-type electron barrier layer, an n-type red channel absorption layer and a second n-type contact layer which are sequentially stacked on the n-type substrate, wherein a first electrode is further arranged on the first n-type contact layer, a second electrode corresponding to the first electrode is arranged on the second n-type contact layer, conduction bands of the n-type blue channel absorption layer, the p-type hole barrier layer and the p-type green channel absorption layer are flush with each other, and valence bands of the p-type green channel absorption layer, the n-type electron barrier layer and the n-type red channel absorption layer are flush with each other.

Preferably, the effective bandwidths of the p-type hole barrier layer, the n-type blue channel absorber layer, and the p-type green channel absorber layer decrease in order.

Preferably, the effective bandwidths of the n-type electron barrier layer, the p-type green channel absorber layer, and the n-type red channel absorber layer decrease in order.

Preferably, the materials of the first n-type contact layer, the n-type blue channel absorption layer, the n-type electron barrier layer, the n-type red channel absorption layer and the second n-type contact layer are Si-doped n-type InAs/GaSb superlattices and/or InAs/InAsSb superlattices.

Preferably, the p-type hole barrier layer is made of a p-type InAs/AlSb superlattice or InAsP/InAsSb superlattice doped with Zn or Be.

Preferably, the p-type green channel absorption layer is made of p-type InAs/GaSb superlattice or InAs/InAsSb superlattice doped with Zn or Be.

Preferably, the material of the n-type substrate is n-type GaSb or InAs.

The invention also discloses a manufacturing method of the multicolor infrared detector, which comprises the following steps:

sequentially laminating a first n-type contact layer, an n-type blue channel absorption layer, a p-type hole barrier layer, a p-type green channel absorption layer, an n-type electron barrier layer, an n-type red channel absorption layer and a second n-type contact layer on an n-type substrate;

partially etching the second n-type contact layer, the n-type red channel absorption layer, the n-type electron barrier layer, the p-type green channel absorption layer, the p-type hole barrier layer and the n-type blue channel absorption layer to expose the first n-type contact layer to form a detector mesa structure;

a first electrode is formed on the first n-type contact layer and a second electrode is formed on the second n-type contact layer.

Preferably, the conduction bands of the n-type blue channel absorber layer, the p-type hole barrier layer, and the p-type green channel absorber layer are flush with each other, while the valence bands of the p-type green channel absorber layer, the n-type electron barrier layer, and the n-type red channel absorber layer are also flush with each other.

Preferably, the effective bandwidths of the p-type hole barrier layer, the n-type blue channel absorber layer, and the p-type green channel absorber layer decrease in order; and/or the effective bandwidths of the n-type electron barrier layer, the p-type green channel absorber layer, and the n-type red channel absorber layer decrease in order.

Compared with the prior art, the invention has the beneficial effects that:

(1) the multicolor infrared detector adopts an NPN structure, respectively corresponds to a blue channel, a green channel and a red channel, and inserts a hole potential barrier between the blue channel and the green channel by utilizing energy band engineering and inserts an electron potential barrier between the green channel and the red channel, thereby being capable of selecting detection of different wave bands by utilizing different bias voltages and well inhibiting crosstalk.

(2) Each wave band of the multicolor infrared detector is of a single heterojunction structure, dark current is well inhibited through insertion of a potential barrier, smooth collection of photocurrent is not affected, the performance of the detector is equivalent to that of a monochromatic detector with the same wave band, and the performance of the detector with each wave band is guaranteed.

(3) The bandwidth between the blue channel, the green channel and the red channel of the multicolor infrared detector is sequentially decreased, so that the multicolor infrared detector can be applied to the combination of different wave bands, such as short wave, medium wave and long wave, and has better universality.

Drawings

FIG. 1 is a schematic diagram of energy bands of functional layers of a conventional multicolor detector

FIG. 2 is a schematic diagram of a multicolor infrared detector of the present invention;

FIGS. 3-6 are flow charts of the fabrication of the multicolor infrared detector of the present invention;

FIG. 7 is a schematic energy band diagram of the functional layers of the multicolor infrared detector of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the invention shown in the drawings and described in accordance with the drawings are exemplary only, and the invention is not limited to these embodiments.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

The structure of the multicolor infrared detector of the present invention is described below with reference to the accompanying drawings. As shown in fig. 2, the basic structure of the multicolor infrared detector of the present invention comprises an n-type substrate 1, and a first n-type contact layer 2, an n-type blue channel absorption layer 3, a p-type hole barrier layer 4, a p-type green channel absorption layer 5, an n-type electron barrier layer 6, an n-type red channel absorption layer 7 and a second n-type contact layer 8 which are sequentially stacked and disposed on the n-type substrate 1. A first electrode 9 is further arranged on the first n-type contact layer 2, and a second electrode 10 corresponding to the first electrode 9 is arranged on the second n-type contact layer 8. As shown in fig. 7, conduction bands of the n-type blue channel absorption layer 3, the p-type hole barrier layer 4 and the p-type green channel absorption layer 5 are flush with each other, so that smooth transport of electrons on the conduction band is ensured, and valence bands of the p-type green channel absorption layer 5, the n-type electron barrier layer 6 and the n-type red channel absorption layer 7 are flush with each other, so that smooth transport of holes on the valence bands is ensured.

The multicolor infrared detector adopts an NPN structure, respectively corresponds to a blue channel, a green channel and a red channel, and inserts a hole potential barrier between the blue channel and the green channel and inserts an electron potential barrier between the green channel and the red channel by utilizing energy band engineering, thereby realizing the detection of different wave bands by utilizing different bias voltages and well inhibiting crosstalk. The principle of operation of the multicolor infrared detector of the present invention is described in detail below, wherein the forward bias is defined as the voltage of the first electrode 9 being greater than the voltage of the second electrode 10, and vice versa.

The multicolor infrared detector is under small positive bias (such as 0.1V), the red channel is under positive bias and can not work, minority carriers of the blue channel can not cross a hole barrier and can not work, and only the green channel under reverse bias works normally;

the multicolor infrared detector is under a large positive bias (such as 0.5V), the red channel can not work under the positive bias state, minority carriers of the blue channel can cross a hole barrier under the bias effect to start working, and the green channel in the reverse bias state is added, so that the green channel and the blue channel can work normally;

the multi-color infrared detector is under a small reverse bias (such as-0.1V), the blue channel is in a forward bias state and can not work, minority carriers of the green channel can not cross an electron barrier and can not work, and at the moment, only the red channel in a reverse bias state works normally;

the multi-color infrared detector of the invention is under the large reverse bias (such as-0.5V), the blue channel is in the forward bias state and can not work, minority carriers of the green channel can cross the electron barrier under the bias effect and start to work, and the red channel in the reverse bias state is added, at this time, the red channel and the green channel can work normally.

Thus, the multicolor infrared detector of the present invention can realize selection of different wavelength bands by using the change of the bias voltage.

Based on the above basic structure, specific embodiments of the present invention are explained below.