Medium wave infrared detection chip and system

Abstract

The invention provides a medium-wave infrared detection chip and system, the chip is composed of a plurality of detection units arranged in the same plane, each detection unit is composed of a substrate, a buffer layer, a lower contact layer, an absorption layer, a barrier layer and an upper contact layer in sequence, the chip is arranged based on an nBp type structure, the buffer layer, the lower contact layer, the absorption layer, the barrier layer and the upper contact layer are all of a multi-period stacked superlattice structure, the thickness, the number of layers and the doping concentration of the InAs doped layers and the GaSb doped layers which are stacked in each period are controlled, dark current suppression in the mid-infrared detection process is achieved, and the quantum efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of infrared detection technology, and in particular to a medium-wave infrared detection chip and system. Background Art

[0002] Mid-Wave Infrared (MWIR) detectors are an important branch of infrared detection technology, usually used to detect infrared radiation in the wavelength range of 3 to 5 μm. This type of detector is widely used in both military and civilian fields. For example, in the military field, it is used for reconnaissance, target identification, missile guidance, and night vision equipment. Due to its good imaging ability and high sensitivity, MWIR detectors can provide clear target images in various complex environments. In the industrial and civilian fields, it can be used for environmental monitoring, gas detection, temperature imaging, and medical imaging. Especially in gas detection, many industrial gases have characteristic absorption in the mid-infrared band, so MWIR detectors can effectively identify and monitor these gases. In addition, in the field of scientific research, MWIR detectors are also used in astronomy and remote sensing technology to observe thermal radiation from celestial bodies and the earth's surface.

[0003] In infrared focal plane detection systems, dark current level and quantum efficiency are important parameters for measuring device performance. In superlattice infrared detectors, the main dark current mechanisms include diffusion current, recombination current, direct tunneling current, and trap-assisted tunneling current. Finding appropriate absorption layer structure materials and adjusting appropriate parameters can effectively reduce the dark current level of the device, improve quantum efficiency, and further enhance the detector performance.

[0004] In the prior art, the second-class superlattice infrared detector is an important branch of today's infrared detection technology. Its application background mainly stems from the demand for high-performance infrared detection equipment. The overall structure is a pπMp structure, which includes a lower electrode, an InAs / GaSb superlattice contact layer and an absorption layer, an InAs / GaSb / AlSb / GaSb superlattice barrier layer, an InAs / GaSb superlattice contact layer and an upper electrode, and the contact layer, the absorption layer and the barrier layer are all p-type regions. However, the second-class superlattice material is still in the initial development stage, and the existing technical means are still not very mature, and the problems of high dark current and low quantum efficiency of the second-class superlattice material have not been solved. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a medium-wave infrared detection chip and system to eliminate or improve one or more defects existing in the prior art and overcome the problems of high dark current and low quantum efficiency of existing medium-wave infrared detectors.

[0006] One aspect of the present invention provides a medium-wave infrared detection chip, which is composed of a plurality of detection units arranged in the same plane, and the detection unit includes: a substrate, a buffer layer, a lower contact layer, an absorption layer, a barrier layer and an upper contact layer.

[0007] The buffer layer is grown on the substrate and is made of p-type gallium-antimony doping material with a doping concentration of 1×10 15 ~1×10 18 cm -3 ;

[0008] A lower contact layer is grown on the buffer layer, wherein the lower contact layer is a multi-periodic stacked arrangement, and each period includes a first InAs doped layer and a first GaSb doped layer of a 9ML / 9ML structure that are continuously arranged; the lower contact layer is p-type doped, and the doping concentrations of the first InAs doped layer and the first GaSb doped layer are 1×10 16 ~1×10 18 cm -3 ;

[0009] The absorption layer is grown on the lower contact layer, and the absorption layer is arranged in a multi-period stacking manner, and each period includes a second InAs doped layer and a second GaSb doped layer of a 9ML / 9ML structure arranged continuously; the absorption layer is p-type doped, and the doping concentration of the second InAs doped layer and the second GaSb doped layer is 1×10 15 ~5×10 16 cm -3 ;

[0010] The barrier layer is grown on the absorption layer, and the barrier layer is arranged in a multi-period stacking manner, and each period includes a third InAs doped layer and a third GaSb doped layer of a 12ML / 7ML structure arranged continuously; the barrier layer is n-type doped, and the doping concentration of the third InAs doped layer and the third GaSb doped layer is 1×10 15 ~1×10 18 cm -3 ;

[0011] The upper contact layer is grown on the barrier layer, and the barrier layer is arranged in a multi-periodic stacking manner, and each period includes a fourth InAs doped layer and a fourth GaSb doped layer of a 5ML / 4ML structure arranged continuously; the upper contact layer is n-type doped, and the doping concentration of the fourth InAs doped layer and the fourth GaSb doped layer is 1×10 16 ~1×10 18 cm -3 .

[0012] In some embodiments, the substrate is a GaSb substrate with a thickness of 0.5 to 1 μm, and the buffer layer has a thickness of 100 to 500 nm.

[0013] In some embodiments, the doping concentration of the first InAs doping layer and the first GaSb doping layer is 5×10 17 cm -3 The doping concentration of the second InAs doped layer and the second GaSb doped layer is 1×10 15 cm -3 The doping concentration of the third InAs doping layer and the third GaSb doping layer is 5×10 17 cm -3 The upper contact layer is n-type doped, and the doping concentration of the fourth InAs doped layer and the fourth GaSb doped layer is 5×10 17 cm -3 .

[0014] In some embodiments, the buffer layer has a thickness of 500 nm, the lower contact layer has a thickness of 1500 nm, the absorption layer has a thickness of 5500 nm, the barrier layer has a thickness of 250 nm, and the upper contact layer has a thickness of 200 nm.

[0015] In some embodiments, the buffer layer doping concentration is 1×10 18 cm -3 .

[0016] On the other hand, the present invention also provides a medium-wave infrared detection system, the device comprising:

[0017] As described above, the medium-wave infrared detection chip, readout circuit, preamplifier, analog-to-digital converter, digital signal processor and data output interface.

[0018] The readout circuit is used to collect and filter the electrical signal generated by the medium-wave infrared detection chip.

[0019] The preamplifier is used to amplify the analog signal output by the readout circuit.

[0020] The analog-to-digital converter is used to convert the analog signal amplified by the preamplifier into a digital signal.

[0021] The digital signal processor performs filtering, signal enhancement, data compression and / or image generation on the digital signal output by the analog-to-digital converter.

[0022] The data output interface is used to output the data obtained after being processed by the digital signal processor.

[0023] In some embodiments, the device further includes: an optical lens for focusing the infrared light beam to be detected and transmitting it to the medium-wave infrared detection chip for photosensitivity.

[0024] In some embodiments, the device is further provided with a temperature control device, wherein the temperature control device comprises:

[0025] A thermistor sensor, used to detect the temperature of the medium-wave infrared detection chip;

[0026] A Dewar cooling device is used to cool and dissipate heat for the medium-wave infrared detection chip; and a temperature control unit is connected to the thermistor sensor and the Dewar cooling device to detect and control the temperature of the medium-wave infrared detection chip.

[0027] In some embodiments, the apparatus further comprises: a display device for displaying the data or image obtained after being processed by the digital signal processor.

[0028] The beneficial effects of the present invention are at least:

[0029] The mid-wave infrared detection chip and system described in the present invention, the chip is composed of a plurality of detection units arranged in the same plane, the detection units are composed of a substrate, a buffer layer, a lower contact layer, an absorption layer, a barrier layer and an upper contact layer in sequence, the chip is arranged based on an nBp-type structure, the buffer layer, the lower contact layer, the absorption layer, the barrier layer and the upper contact layer all adopt a superlattice structure with a multi-period stacked arrangement, and the thickness, number of layers and doping concentration of the multi-layer InAs doped layer and GaSb doped layer stacked in each period are controlled to achieve suppression of dark current in the mid-infrared detection process and effectively improve quantum efficiency.

[0030] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically indicated in the specification and the accompanying drawings.

[0031] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute a limitation of the present invention. In the drawings:

[0033] Figure 1This is a structural diagram of a single detection unit in a medium-wave infrared detection chip according to an embodiment of the present invention.

[0034] Figure 2 This is an energy band diagram of the nBp structure used in the medium-wave infrared detection chip described in another embodiment of the present invention.

[0035] Figure 3 (a) is the relationship between quantum efficiency and wavelength at 77K; Figure 3 (b) is the relationship between dark current density and bias voltage under 77K conditions.

[0036] Figure 4 It is a schematic structural diagram of a medium-wave infrared detection system according to an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram of the structure of a medium-wave infrared detection system according to another embodiment of the present invention.

[0038] 110: medium-wave infrared detection chip; 111: upper contact layer; 112: barrier layer;

[0039] 113: absorption layer; 114: lower contact layer; 115: buffer layer;

[0040] 116: substrate; 120: readout circuit; 130: preamplifier;

[0041] 140: analog-to-digital converter; 150: digital signal processor; 160: data output interface;

[0042] 210: optical lens; 310: temperature control device; 311: thermistor sensor;

[0043] 312: thermoelectric cooler; 313: heat sink; 314: temperature control unit. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0045] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0046] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0047] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0048] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0049] The medium-wave infrared detection chip in this application adopts an nBp-type structure with a flexible and adjustable design. By precisely controlling the thickness of the absorption region and the doping level, the optimization of dark current and quantum efficiency and other results is achieved, thereby improving the overall performance of the photoelectric conversion device. Specifically, this structure can cleverly construct an efficient electronic barrier by adjusting the parameters of each region. This barrier is formed by a wide-bandgap barrier layer, which not only provides a significant valence band offset to ensure effective blocking of holes, but also maintains a smaller conduction band offset to support smooth transmission of electrons. By optimizing the doping concentration, the mobility and lifetime of photogenerated electrons (as minority carriers) can be significantly increased, thereby improving the efficiency of these electrons being collected. This process not only reduces unnecessary diffusion current, but also significantly improves the quantum efficiency of the device, that is, the ratio of unit incident photons converted into usable electrical signals.

[0050] Specifically, Figure 1 As shown, the present invention provides a medium-wave infrared detection chip 110, which is composed of a plurality of detection units arranged in the same plane, and the detection unit includes: a substrate 116, a buffer layer 115, a lower contact layer 114, an absorption layer 113, a barrier layer 112 and an upper contact layer 111.

[0051] In some embodiments, the substrate 116 is a GaSb substrate 116 with a thickness of 0.5-1 μm, and the buffer layer 115 has a thickness of 100-500 nm.

[0052] The buffer layer 115 is grown on the substrate 116 and is made of p-type doping material based on GaSb with a doping concentration of 1×10 15 ~1×10 18 cm -3 ;

[0053] The lower contact layer 114 is grown on the buffer layer 115. The lower contact layer 114 is a multi-periodic stacked arrangement, and each period includes a first InAs doped layer and a first GaSb doped layer of a 9ML / 9ML structure that are continuously arranged. The lower contact layer 114 is p-type doped, and the doping concentration of the first InAs doped layer and the first GaSb doped layer is 1×10 16 ~1×10 18 cm -3 ML represents a thickness of 0.3 nm, and a 9ML / 9ML structure represents a first InAs doping layer of 9×0.3 nm thickness and a first GaSb doping layer of 9×0.3 nm thickness.

[0054] The absorption layer 113 is grown on the lower contact layer 114. The absorption layer 113 is a multi-periodic stacked arrangement. Each period includes a second InAs doped layer and a second GaSb doped layer of a 9ML / 9ML structure that are continuously arranged. The absorption layer 113 is p-type doped. The doping concentration of the second InAs doped layer and the second GaSb doped layer is 1×10 15 ~1×10 16 cm -3 ML represents a thickness of 0.3 nm, and a 9ML / 9ML structure represents a second InAs doped layer with a thickness of 9×0.3 nm and a second GaSb doped layer with a thickness of 9×0.3 nm.

[0055] The barrier layer 112 is grown on the absorption layer 113. The barrier layer 112 is arranged in a multi-periodic stacking manner. Each period includes a third InAs doped layer and a third GaSb doped layer of a 12ML / 7ML structure arranged continuously. The barrier layer 112 is n-type doped. The doping concentration of the third InAs doped layer and the third GaSb doped layer is 1×10 15 ~1×10 18 cm -3 ML represents a thickness of 0.3 nm, and a 12ML / 7ML structure represents a third InAs doping layer with a thickness of 12×0.3 nm and a third GaSb doping layer with a thickness of 7×0.3 nm.

[0056] The upper contact layer 111 is grown on the barrier layer 112. The barrier layer 112 is arranged in a multi-periodic stacking manner. Each period includes a fourth InAs doped layer and a fourth GaSb doped layer of a 5ML / 4ML structure arranged continuously. The upper contact layer 111 is n-type doped. The doping concentration of the fourth InAs doped layer and the fourth GaSb doped layer is 1×10 16 ~1×10 18 cm -3 ML represents a thickness of 0.3 nm, and a 5ML / 4ML structure represents a fourth InAs doping layer with a thickness of 5×0.3 nm and a fourth GaSb doping layer with a thickness of 4×0.3 nm.

[0057] In some embodiments, the doping concentration of the first InAs doping layer and the first GaSb doping layer is 5×10 17 cm -3 The doping concentration of the second InAs doped layer and the second GaSb doped layer is 1×10 15 cm -3 The doping concentration of the third InAs doping layer and the third GaSb doping layer is 5×10 17 cm -3 The upper contact layer 111 is n-type doped, and the doping concentration of the fourth InAs doped layer and the fourth GaSb doped layer is 5×10 17 cm -3 .

[0058] In some embodiments, the thickness of the buffer layer 115 is 500 nm, the thickness of the lower contact layer 114 is 1500 nm, the thickness of the absorption layer 113 is 5500 nm, the thickness of the barrier layer 112 is 250 nm, and the thickness of the upper contact layer 111 is 200 nm.

[0059] In some embodiments, the buffer layer doping concentration is 1×10 18 cm -3 .

[0060] In this embodiment, an nBp-type structure is used, in which a higher electron barrier is formed, so that the wide bandgap barrier layer provides a larger valence band offset and a minimum conduction band offset, thereby further reducing the dark current. On this basis, the absorption layer parameters of the structure are optimized, effectively improving the overall performance of the device.

[0061] The structure can obtain the relationship between capacitance and voltage according to the following formula, and adjusting the electron concentration therein can deepen the electron potential well, thereby further reducing the generation of dark current.

[0062]

[0063] Where C represents the unit heterojunction capacitance, q is the electron charge, T represents the temperature, and ξ 1 represents the dielectric constant of the narrowband material, ξ 2 Represents the dielectric constant of broadband materials, N A1 Represents the impurity concentration of the narrowband P region, N D2 represents the donor impurity concentration in the broadband N region (parameters for narrowband materials are marked 1, and parameters for broadband materials are marked 2), and θ represents the ratio of minority carriers to majority carriers on the interface.

[0064]

[0065] Among them, V D1 With V D2 Represent the potential barrier heights on both sides respectively.

[0066] Through qualitative analysis of the following formula, we can know that the greater the doping concentration, the smaller the dark current, but when the doping concentration is too high, the electric field will also increase, which will increase the value of the tunneling current to a certain extent.

[0067]

[0068] Among them, J SRH is the composite current density, q is the electron charge, n i is the intrinsic carrier concentration, τ n and τ p are the lifetimes of electrons and holes, respectively, and n and p are the electron and hole concentrations, respectively.

[0069] The formula related to quantum efficiency η is as follows:

[0070]

[0071] Among them, α is the absorption coefficient of the material, L is the thickness of the absorption layer, R is the reflectivity of the surface, and d is the depth of the incident light to the absorption layer. Through the above formula, it can be qualitatively analyzed that under the same conditions, the greater the thickness of the absorption zone, the higher the quantum efficiency.

[0072] In view of the relationship given in the above formula, an embodiment of the present invention provides a new type of nBp device structure and optimizes it. For the absorption layer, the material ratio of InAs and GaSb is controlled, and the thickness and doping concentration of the absorption layer are strictly screened to achieve higher performance. At the same time, the absorption region adopts p-type doping to ensure the minority carrier type, the barrier layer and the top absorption layer adopt n-type doping, and the bottom absorption layer adopts p-type doping, forming an nBp type structure as a whole, which comprehensively ensures the optimal overall performance of the device structure.

[0073] This embodiment proposes an nBp structure for infrared detection in the mid-wave (3-5 μm) band, and optimizes the doping, thickness and other parameter levels of each layer of the device. The device structure uses an InAs / GaSb superlattice structure as the contact layer, absorption layer and barrier layer. The absorption layer is weakly doped with a doping concentration of 1×10 15 cm -3 (Generally, the doping concentration range is 10 15 ~0 16 cm -3 ); the contact layer is heavily doped with a doping concentration of 5×10 17 cm -3 (Generally, the doping concentration range is 10 16 ~10 18 cm -3 ); the barrier layer is between the absorption layer and the contact layer, and the doping concentration is 5×10 15cm -3 (Generally, the doping concentration range is 10 15 ~10 18 cm -3 ). This embodiment screens and optimizes the absorption layer material to ensure that the device has a high quantum efficiency.

[0074] Specifically, a medium- and long-wave infrared detector is provided, which includes, from top to bottom:

[0075] 111-InAs / GaSb superlattice upper contact layer.

[0076] 112-InAs / GaSb superlattice barrier layer.

[0077] 113-InAs / GaSb superlattice absorber layer.

[0078] 114-InAs / GaSb superlattice lower contact layer.

[0079] 115-GaSb buffer layer.

[0080] 116-GaSb substrate.

[0081] Specifically, a 500 nm GaSb buffer layer 115 is grown on a GaSb substrate 116, and the p-type doping concentration is 1×10 18 cm -3 ; A 1500nm superlattice structure is grown on the buffer layer 115 as the bottom contact layer, p-type doped, with a doping concentration of 5×10 17 cm -3 The superlattice structure is 9ML InAs / 9ML GaSb; a 5500nm superlattice structure is grown on the lower contact layer 114 as the absorption layer 113, p-type doping, and the doping concentration is 1×10 15 cm -3 The superlattice structure is 9ML InAs / 9ML GaSb; a 250nm superlattice structure is grown on the absorption layer 113 as the barrier layer 112, which is n-type doped with a doping concentration of 5×10 15 cm -3 The superlattice structure is 12ML InAs / 7ML GaSb; a 200nm superlattice structure is grown on the barrier layer 112 as the upper contact layer 111, which is n-type doped with a doping concentration of 5×10 17 cm -3, the superlattice structure is 5ML InAs / 4ML GaSb; the electrode can be installed between the lower contact layer 114 and the buffer layer 115, and above the upper contact layer 111. Among them, ML represents a thickness unit, each ML is 0.3nm, and the exemplary "9ML InAs / 9ML GaSb" means that the InAs doped layer with a thickness of 9×0.3nm and the GaSb doped layer with a thickness of 9×0.3nm are used as a period, and multiple periods are stacked.

[0082] Figure 2 is the energy band diagram of the nBp device structure. It can be clearly seen that the barrier region forms a significant hole barrier in the valence band, which effectively separates the upper contact layer 111 from the absorption layer 113. Therefore, it prevents most of the holes injected by the upper contact layer 111 from entering the absorption layer 113, thereby avoiding the potential interference of these holes on the photoexcitation process of the absorption layer 113. At the same time, in the conduction band, there is also a barrier in the barrier region, which is caused by the fact that the absorption region and the barrier region use the same doping type but different doping concentrations. The difference in doping concentrations between the two regions directly affects the height of the conduction band barrier. Since the absorption layer 113 and the upper contact layer 111 use the same superlattice material, the existence of this conduction band barrier plays a significant blocking role under lower bias conditions, resulting in a very low dark current density.

[0083] Under lower bias voltage, although the dark current property is good, it is difficult for photogenerated carriers to cross the potential barrier and be collected by the electrode. Only when the turn-on voltage is reached can the photogenerated carriers be collected normally, which is limited by the height of the conduction band barrier. To this end, the conduction band barrier height of the barrier layer 112 material is precisely designed to be about 0.2eV, so that photogenerated carriers can be efficiently collected at a bias voltage of -0.2V, significantly reducing the device process requirements.

[0084] like Figure 3 As shown, under 77K, a bias voltage of -0.2V is applied to the lower contact layer 114 of the device. Before optimization, the dark current density of the structure is 10 -4 -10 -5 A / cm 2 , the quantum efficiency peak is less than 35%; after optimization, at a temperature of 77K, when a -0.2V bias is applied to the lower contact layer 114 of the device, the dark current density is significantly reduced to less than 10 -6 A / cm 2 At the same time, the peak quantum efficiency is greater than 45%, achieving dual optimization of low dark current and high quantum efficiency, significantly improving the overall performance of the device.

[0085] On the other hand, the present invention also provides a medium-wave infrared detection system, the device comprising:

[0086] The medium-wave infrared detection chip 110, the readout circuit 120, the preamplifier 130, the analog-to-digital converter 140, the digital signal processor 150 and the data output interface 160 are as described above.

[0087] The readout circuit 120 is used to collect and filter the electrical signal generated by the medium-wave infrared detection chip 110 .

[0088] The preamplifier 130 is used to amplify the analog signal output by the readout circuit 120 .

[0089] The analog-to-digital converter 140 is used to convert the amplified analog signal output by the preamplifier 130 into a digital signal.

[0090] The digital signal processor 150 performs filtering, signal enhancement, data compression and / or image generation on the digital signal output by the analog-to-digital converter 140 .

[0091] The data output interface 160 is used to output the data processed by the digital signal processor 150 .

[0092] In some embodiments, the device further includes: an optical lens 210 for focusing the infrared light beam to be detected and transmitting it to the medium-wave infrared detection chip 110 for photosensitization.

[0093] In some embodiments, the device is further provided with a temperature control device 310, and the temperature control device 310 comprises:

[0094] Thermistor sensor 311 is used to detect the temperature of the medium-wave infrared detection chip 110;

[0095] Dewar refrigeration equipment 312, used for cooling and dissipating the medium-wave infrared detection chip 110;

[0096] The temperature control unit 313 is connected to the thermistor sensor 311 and the Dewar cooling device 312 to perform temperature detection and control on the medium-wave infrared detection chip 110 .

[0097] In some embodiments, the apparatus further includes: a display device for displaying the data or image obtained after being processed by the digital signal processor 150 .

[0098] In summary, the mid-wave infrared detection chip and system described in the present invention, the chip is composed of a plurality of detection units arranged in the same plane, the detection unit is composed of a substrate, a buffer layer, a lower contact layer, an absorption layer, a barrier layer and an upper contact layer in sequence, the chip is arranged based on an nBp-type structure, the buffer layer, the lower contact layer, the absorption layer, the barrier layer and the upper contact layer all adopt a superlattice structure with a multi-period stacked arrangement, and the thickness, number of layers and doping concentration of the multi-layer InAs doped layer and GaSb doped layer stacked in each period are controlled to achieve suppression of dark current in the mid-infrared detection process and effectively improve the quantum efficiency.

[0099] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0100] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0101] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A medium-wave infrared detection chip, characterized in that: The medium-wave infrared detection chip is composed of a plurality of detection units arranged in the same plane, and the detection units include: substrate; The buffer layer is grown on the substrate and is made of p-type gallium-antimony doping material with a doping concentration of 1×10 15 ~1×10 18 cm -3 ; A lower contact layer is grown on the buffer layer, wherein the lower contact layer is a multi-periodic stacked arrangement, and each period includes a first InAs doped layer and a first GaSb doped layer of a 9ML / 9ML structure that are continuously arranged; the lower contact layer is p-type doped, and the doping concentrations of the first InAs doped layer and the first GaSb doped layer are 1×10 16 ~1×10 18 cm -3 ; The absorption layer is grown on the lower contact layer, and the absorption layer is arranged in a multi-period stacking manner, and each period includes a second InAs doped layer and a second GaSb doped layer of a 9ML / 9ML structure arranged continuously; the absorption layer is p-type doped, and the doping concentration of the second InAs doped layer and the second GaSb doped layer is 1×10 15 ~5×10 16 cm -3 ; The barrier layer is grown on the absorption layer, and the barrier layer is arranged in a multi-period stacking manner, and each period includes a third InAs doped layer and a third GaSb doped layer of a 12ML / 7ML structure arranged continuously; the barrier layer is n-type doped, and the doping concentration of the third InAs doped layer and the third GaSb doped layer is 1×10 15 ~1×10 18 cm -3 ; The upper contact layer is grown on the barrier layer, and the barrier layer is arranged in a multi-periodic stacking manner, and each period includes a fourth InAs doped layer and a fourth GaSb doped layer of a 5ML / 4ML structure arranged continuously; the upper contact layer is n-type doped, and the doping concentration of the fourth InAs doped layer and the fourth GaSb doped layer is 1×10 16 ~1×10 18 cm -3 .

2. The medium-wave infrared detection chip according to claim 1, characterized in that: The thickness of the substrate is 0.5-1 μm, and the thickness of the buffer layer is 100-500 nm.

3. The medium-wave infrared detection chip according to claim 2, characterized in that: The doping concentration of the first InAs doping layer and the first GaSb doping layer is 5×10 17 cm -3 The doping concentration of the second InAs doped layer and the second GaSb doped layer is 1×10 15 cm -3 The doping concentration of the third InAs doping layer and the third GaSb doping layer is 5×10 17 cm -3 The upper contact layer is n-type doped, and the doping concentration of the fourth InAs doped layer and the fourth GaSb doped layer is 5×10 17 cm -3 .

4. The medium-wave infrared detection chip according to claim 3, characterized in that: The thickness of the buffer layer is 500 nm, the thickness of the lower contact layer is 1500 nm, the thickness of the absorption layer is 5500 nm, the thickness of the barrier layer is 250 nm, and the thickness of the upper contact layer is 200 nm.

5. The medium-wave infrared detection chip according to claim 4, characterized in that: The doping concentration of the buffer layer is 1×10 18 cm -3 .

6. The medium-wave infrared detection chip according to claim 5, characterized in that: The substrate is made of GaSb material.

7. A medium-wave infrared detection system, characterized in that: The device comprises: The medium-wave infrared detection chip according to any one of claims 1 to 6; A readout circuit, used for collecting and filtering the electrical signal generated by the medium-wave infrared detection chip; A preamplifier, used to amplify the analog signal output by the readout circuit; An analog-to-digital converter, used for converting the analog signal amplified by the preamplifier into a digital signal; A digital signal processor, for filtering, signal enhancement, data compression and / or image generation of the digital signal output by the analog-to-digital converter; The data output interface is used to output the data obtained after being processed by the digital signal processor.

8. The medium-wave infrared detection system according to claim 7, characterized in that: The device also includes: The optical lens is used to focus the infrared light beam to be detected and transmit it to the medium-wave infrared detection chip for photosensitivity.

9. The medium-wave infrared detection system according to claim 7, characterized in that: The device is also provided with a temperature control device, and the temperature control device comprises: A thermistor sensor, used to detect the temperature of the medium-wave infrared detection chip; Dewar refrigeration equipment, used for cooling and dissipating the medium-wave infrared detection chip; A temperature control unit is connected to the thermistor sensor and the Dewar refrigeration device to perform temperature detection and control on the medium-wave infrared detection chip.

10. The medium-wave infrared detection system according to claim 7, characterized in that: The device also includes: The display device is used to display the data or image obtained after being processed by the digital signal processor.

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