Infrared Detector and Its Manufacturing Method

Abstract

The present invention discloses an infrared detector, wherein the P-type superlattice barrier layer (14) is a P-type InPSb / GaSb superlattice. The present invention uses an InPSb / GaSb superlattice to form an electron barrier layer, and the barrier height thereof is higher than that of a conventional InAs / GaSb superlattice electron barrier, thereby improving the electron blocking effect. The present invention also discloses an infrared detector, wherein the N-type superlattice barrier layer (12) is an N-type InPSb / GaSb superlattice. The present invention uses an InPSb / GaSb superlattice to form a hole barrier layer. Since it does not contain Al, oxidation of Al-containing materials is avoided, the difficulty of material growth and processing is reduced, and the stability and reliability of the device are improved. The present invention also discloses a manufacturing method of an infrared detector.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and more specifically, relates to an infrared detector and a method for manufacturing the same. Background Art

[0002] Infrared radiation detection is an important part of infrared technology and is widely used in fields such as thermal imaging, satellite remote sensing, gas monitoring, optical communication, and spectral analysis. Antimonide superlattice (e.g., InAs / GaSb and InAs / InAsSb) infrared detectors are considered to be one of the most ideal choices for fabricating third-generation infrared detectors due to their good uniformity, low Auger recombination rate, and large wavelength tuning range. Compared with mercury cadmium telluride infrared detectors (HgCdTe), it has better uniformity and repeatability, lower cost, and better performance in very long wavelength bands; compared with quantum well infrared detectors (QWIP), it has higher quantum efficiency, lower dark current, and simpler processes.

[0003] An important noise source of infrared detectors is dark current. Currently, in order to suppress dark current, in the structural design of antimonide superlattice detectors, potential barrier layers are usually introduced into the device by using energy band engineering, such as the M structure of Northwestern University in the United States (B.-M. Nguyen et al, Appl. Phys. Lett. 91, 163511, 2007), the W structure of the Naval Research Laboratory (I. Vurgaftman et al, Appl. Phys. Lett. 89, 121114, 2006), the electron-hole complementary potential barrier of the Jet Propulsion Laboratory (David Z.-Y. Ting et al, Appl. Phys. Lett. 95, 023508, 2009), etc. In these prior art solutions, the electron potential barriers all use InAs / GaSb superlattices, and there are many hole potential barrier solutions, but without exception, they all use Al-containing materials such as InAs / AlSb superlattices, InAs / GaSb / AlSb / GaSb superlattices, or InAs / InGaSb / InAs / AlGaInSb superlattices.

[0004] However, in the prior art solutions, one of the existing problems is that the height of the electron potential barrier using InAs / GaSb superlattice is limited, which will affect the electron blocking effect. In addition, in the prior art solutions, the second existing problem is that all hole potential barriers contain Al, and Al-containing materials are extremely easy to oxidize, which will increase the growth and processing difficulty of infrared detectors and affect the stability and reliability of the devices. Summary of the Invention

[0005] To solve the above-mentioned problem, the present invention provides an infrared detector with a P-type superlattice potential barrier layer of P-type InPSb / GaSb superlattice and a method for manufacturing the same.

[0006] To solve the second of the above problems, the present invention provides an infrared detector with an N-type superlattice barrier layer being an N-type InPSb / GaSb superlattice and a manufacturing method thereof.

[0007] According to an aspect of an embodiment of the present invention, for the provided infrared detector, the P-type superlattice barrier layer of the infrared detector is a P-type InPSb / GaSb superlattice.

[0008] In an example of the infrared detector provided in the above aspect, the N-type superlattice barrier layer of the infrared detector is an N-type InPSb / GaSb superlattice.

[0009] According to another aspect of an embodiment of the present invention, for the provided infrared detector, the N-type superlattice barrier layer of the infrared detector is an N-type InPSb / GaSb superlattice.

[0010] In an example of the infrared detector provided in the above another aspect, the P-type superlattice barrier layer of the infrared detector is a P-type InPSb / GaSb superlattice.

[0011] In an example of the infrared detector provided in the above aspect or another aspect, the infrared detector further includes: a substrate, an N-type contact layer, a superlattice absorption layer, a P-type contact layer, a first electrode, and a second electrode; wherein, the N-type contact layer, the N-type superlattice barrier layer, the superlattice absorption layer, the P-type superlattice barrier layer, and the P-type contact layer are sequentially stacked on the substrate, the first electrode is disposed on the N-type contact layer, and the second electrode is disposed on the P-type contact layer.

[0012] In an example of the infrared detector provided in the above aspect or another aspect, the effective bandwidth of the N-type superlattice barrier layer is greater than the effective bandwidth of the superlattice absorption layer, and the conduction band of the N-type superlattice barrier layer is flush with the conduction band of the superlattice absorption layer; and / or, the effective bandwidth of the P-type superlattice barrier layer is greater than the effective bandwidth of the superlattice absorption layer, and the valence band of the P-type superlattice barrier layer is flush with the valence band of the superlattice absorption layer.

[0013] In an example of the infrared detector provided in the above aspect or another aspect, the N-type contact layer is made of N-type InAs or InAsSb material; and / or, the superlattice absorption layer is an InAs / GaSb superlattice or an InAs / InAsSb superlattice; and / or, the P-type contact layer is made of P-type GaSb or GaAsSb material; and / or, the substrate is an N-type InAs substrate or an N-type GaSb substrate.

[0014] A method for manufacturing an infrared detector provided according to another aspect of an embodiment of the present invention, wherein a P-type superlattice barrier layer of the infrared detector is formed by using a P-type InPSb / GaSb superlattice.

[0015] In an example of the method for manufacturing an infrared detector provided according to the above another aspect, an N-type superlattice barrier layer of the infrared detector is formed by using an N-type InPSb / GaSb superlattice.

[0016] A method for manufacturing an infrared detector provided according to still another aspect of an embodiment of the present invention, wherein an N-type superlattice barrier layer of the infrared detector is formed by using an N-type InPSb / GaSb superlattice.

[0017] In an example of the method for manufacturing an infrared detector provided according to the above still another aspect, a P-type superlattice barrier layer of the infrared detector is formed by using a P-type InPSb / GaSb superlattice.

[0018] In an example of the method for manufacturing an infrared detector provided according to the above another aspect or still another aspect, before forming the N-type superlattice barrier layer of the infrared detector, the manufacturing method further includes: forming an N-type contact layer on a substrate; forming the N-type superlattice barrier layer of the infrared detector includes: forming the N-type superlattice barrier layer on the N-type contact layer by using an N-type InPSb / GaSb superlattice; before forming the P-type superlattice barrier layer of the infrared detector, the manufacturing method further includes: forming a superlattice absorption layer on the N-type superlattice barrier layer; forming the P-type superlattice barrier layer of the infrared detector includes: forming a P-type superlattice barrier layer on the superlattice absorption layer by using a P-type InPSb / GaSb superlattice; after forming the P-type superlattice barrier layer of the infrared detector, the manufacturing method further includes: forming a P-type contact layer on the P-type superlattice barrier layer; forming a first electrode in contact with the N-type contact layer, and depositing a second electrode on the P-type contact layer.

[0019] In an example of the method for manufacturing an infrared detector provided according to the above another aspect or still another aspect, the effective bandwidth of the N-type superlattice barrier layer is greater than the effective bandwidth of the superlattice absorption layer, and the conduction band of the N-type superlattice barrier layer is flush with the conduction band of the superlattice absorption layer; and / or, the effective bandwidth of the P-type superlattice barrier layer is greater than the effective bandwidth of the superlattice absorption layer, and the valence band of the P-type superlattice barrier layer is flush with the valence band of the superlattice absorption layer.

[0020] In an example of the method for manufacturing an infrared detector provided in the above-mentioned further aspect or another aspect, the N-type contact layer is made of N-type InAs or InAsSb material; and / or, the superlattice absorption layer is an InAs / GaSb superlattice or an InAs / InAsSb superlattice; and / or, the P-type contact layer is made of P-type GaSb or GaAsSb material; and / or, the substrate is an N-type InAs substrate or an N-type GaSb substrate.

[0021] In an example of the method for manufacturing an infrared detector provided in the above-mentioned further aspect or another aspect, the N-type contact layer and / or the N-type superlattice barrier layer and / or the superlattice absorption layer and / or the P-type superlattice barrier layer and / or the P-type contact layer are formed by metalorganic chemical vapor deposition or molecular beam epitaxy.

[0022] Advantages of the present invention: The present invention uses an InPSb / GaSb superlattice to form an electron barrier layer, and the barrier height is higher than that of the conventional InAs / GaSb superlattice electron barrier, thereby improving the electron blocking effect.

[0023] In addition, the present invention uses an InPSb / GaSb superlattice to form a hole barrier layer. Since it does not contain Al, oxidation of the Al-containing material is avoided, the difficulty of material growth and processing is reduced, and the stability and reliability of the device are improved.

[0024] Furthermore, the present invention uses the same material, i.e., the InPSb / GaSb superlattice, to form the electron barrier layer and the hole barrier layer, greatly reducing the difficulty of device manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Through the following description in conjunction with the drawings, the above and other aspects, features, and advantages of the embodiments of the present invention will become clearer. In the drawings:

[0026] Figure 1 is a schematic structural diagram of an infrared detector according to an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of the energy bands in an infrared detector according to an embodiment of the present invention;

[0028] Figure 3 is a comparative schematic diagram of the relative positions of the conduction band E C and valence band E V in the InAs / GaSb superlattice absorption layer, N-type InPSb / GaSb superlattice barrier layer, and P-type InPSb / GaSb superlattice barrier layer in an infrared detector according to an embodiment of the present invention;

[0029] Figures 4a to 4dIt is a process diagram of a method for manufacturing an infrared detector according to an embodiment of the present invention. Detailed Embodiments

[0030] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different forms, and the present invention should not be construed as being limited to the specific embodiments set forth herein. On the contrary, these embodiments are provided to explain the principles of the present invention and its practical applications, so that other technical personnel in the art can understand various embodiments of the present invention and various modifications suitable for specific intended applications.

[0031] As used herein, the term "comprising" and its variants represent open terms, meaning "including but not limited to". Terms such as "based on", "according to", etc. mean "at least partially based on", "at least partially according to". The terms "embodiment", "an example", "an embodiment", and "one embodiment" mean "at least one embodiment". The terms "another embodiment", "another example", "another embodiment", and "yet another example" mean "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other definitions may be included below, whether explicit or implicit. Unless clearly specified in the context, the definition of a term is consistent throughout the specification.

[0032] Here, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution according to the present invention are shown in the drawings, and other details of little relevance are omitted.

[0033] As described in the background art, for infrared detectors, in the solutions of the prior art, one of the problems is that the height of the electron barrier of InAs / GaSb superlattice is limited, which will affect the electron blocking effect. In addition, in the solutions of the prior art, another problem is that the hole barriers all contain aluminum (Al), and the Al-containing material is extremely easy to be oxidized, which will increase the growth and processing difficulty of the infrared detector and affect the stability and reliability of the infrared detector.

[0034] Therefore, in order to increase the height of the electron barrier, an infrared detector using a P-type InPSb / GaSb superlattice to form a P-type superlattice barrier layer is provided according to an embodiment of the present invention. In this infrared detector, the P-type superlattice barrier layer is a P-type InPSb / GaSb superlattice. In addition, a method for manufacturing an infrared detector is also provided according to an embodiment of the present invention. In this method for manufacturing an infrared detector, a P-type superlattice barrier layer is formed using a P-type InPSb / GaSb superlattice.

[0035] Since the barrier height of the P-type InPSb / GaSb superlattice is higher than that of the traditional InAs / GaSb superlattice electron barrier, the electron barrier layer formed by using the InPSb / GaSb superlattice has a higher barrier height, thereby improving the effect of electron blocking.

[0036] In addition, in order to avoid aluminum in the hole barrier, an infrared detector using an N-type InPSb / GaSb superlattice to form an N-type superlattice barrier layer is provided according to an embodiment of the present invention. In this infrared detector, the N-type superlattice barrier layer is an N-type InPSb / GaSb superlattice. In addition, a manufacturing method of an infrared detector is provided according to an embodiment of the present invention. In the manufacturing method of this infrared detector, an N-type superlattice barrier layer is formed by using an N-type InPSb / GaSb superlattice.

[0037] Since the N-type InPSb / GaSb superlattice does not contain Al, the N-type superlattice barrier layer formed by it is not easily oxidized, thereby reducing the growth and processing difficulty of the infrared detector, and further improving the stability and reliability of the infrared detector.

[0038] The infrared detectors according to the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] Figure 1 is a schematic structural diagram of an infrared detector according to an embodiment of the present invention.

[0040] Referring to Figure 1 , the infrared detector according to an embodiment of the present invention includes: a substrate 10; an N-type contact layer 11, an N-type superlattice barrier layer 12, a superlattice absorption layer 13, a P-type superlattice barrier layer 14, and a P-type contact layer 15 stacked from bottom to top; and a first electrode 16 and a second electrode 17; wherein, the first electrode 16 is in contact with the N-type contact layer 11, and the second electrode 17 is disposed on the P-type contact layer 15.

[0041] In one example, the P-type contact layer 15, the P-type superlattice barrier layer 14, the superlattice absorption layer 13, and the N-type superlattice barrier layer 12 can be locally etched by, for example, an inductively coupled plasma etching (ICP) process, so that the N-type contact layer 11 is exposed, and then a mesa structure A is formed. In this case, the first electrode 16 can be disposed on the exposed N-type contact layer 11, that is, on the mesa structure A.

[0042] In one example, the substrate 10 is an N-type InAs substrate or an N-type GaSb substrate.

[0043] In one example, the N-type contact layer 11 is made of N-type InAs or InAsSb material.

[0044] In one example, the superlattice absorption layer 13 is an InAs / GaSb superlattice or an InAs / InAsSb superlattice.

[0045] In one example, the P-type contact layer 15 is made of P-type GaSb or GaAsSb material.

[0046] In one example, the P-type superlattice barrier layer 14 is a P-type InPSb / GaSb superlattice, and the N-type superlattice barrier layer 12 is an InAs / AlSb superlattice, an InAs / GaSb / AlSb / GaSb superlattice, or an InAs / InGaSb / InAs / AlGaInSb superlattice. In this case, since the barrier height of the P-type InPSb / GaSb superlattice is higher than that of the conventional InAs / GaSb superlattice electron barrier, the electron barrier layer (i.e., the P-type superlattice barrier layer 14) formed by using the InPSb / GaSb superlattice has a higher barrier height, thus improving the electron blocking effect.

[0047] In another example, the P-type superlattice barrier layer 14 is an InAs / GaSb superlattice, and the N-type superlattice barrier layer 12 is an N-type InPSb / GaSb superlattice. In this case, since the N-type InPSb / GaSb superlattice does not contain Al, the N-type superlattice barrier layer 12 formed by it is not easily oxidized, thus reducing the growth and processing difficulty of the infrared detector, and further improving the stability and reliability of the infrared detector.

[0048] In yet another example, the P-type superlattice barrier layer 14 is a P-type InPSb / GaSb superlattice, and the N-type superlattice barrier layer 12 is an N-type InPSb / GaSb superlattice. In this case, in addition to the above two beneficial effects (high barrier height and not easily oxidized), using the same material (i.e., the InPSb / GaSb superlattice) to form the P-type superlattice barrier layer 14 and the N-type superlattice barrier layer 12 can further reduce the growth and preparation difficulty.

[0049] Further, in one example, the thickness of the N-type contact layer 11 is 0.1 μm to 0.5 μm, the doping source is Si, and the doping concentration is 1×10 18 cm -3 ~1×10 19 cm -3 , and the corresponding bandwidth is 0.3 eV to 0.4 eV.

[0050] In one example, the thickness of the N-type superlattice barrier layer 12 is 0.2 μm to 0.5 μm, the doping source is Si, and the doping concentration is 1×1018 cm -3 ~1 × 10 19 cm -3 , and the corresponding bandwidth is 0.3 eV to 0.5 eV.

[0051] In one example, the thickness of the superlattice absorption layer 13 is 2 μm to 5 μm, and it is unintentionally doped, and the corresponding bandwidth is 0.1 eV to 0.3 eV.

[0052] In one example, the thickness of the P-type superlattice barrier layer 14 is 0.2 μm to 0.5 μm, the doping source is selected from Zn or Be, and the doping concentration is 1 × 10 18 cm -3 ~1 × 10 19 cm -3 , and the corresponding bandwidth is 0.3 eV to 0.5 eV.

[0053] In one example, the thickness of the P-type contact layer 15 is 0.1 μm to 0.5 μm, the doping source is selected from Zn or Be, and the doping concentration is 1 × 10 18 cm -3 ~1 × 10 19 cm -3 , and the corresponding bandwidth is 0.6 eV to 0.8 eV.

[0054] The energy bands in the infrared detector according to the embodiments of the present invention are described in detail below. Figure 2 It is a schematic diagram of the energy bands in the infrared detector according to the embodiments of the present invention.

[0055] Referring to Figure 1 and Figure 2 together, the effective bandwidth of the N-type superlattice barrier layer 12 is made greater than the effective bandwidth of the superlattice absorption layer 13, and the conduction band E C of the N-type superlattice barrier layer 12 is made C flush with the conduction band E of the superlattice absorption layer 13, so that a hole barrier can be formed.

[0056] In addition, the effective bandwidth of the P-type superlattice barrier layer 14 is made greater than the effective bandwidth of the superlattice absorption layer 13, and the valence band E V of the P-type superlattice barrier layer 14 is made V flush with the valence band E of the superlattice absorption layer 13, so that an electron barrier can be formed.

[0057] Therefore, when the infrared detector is operating, a double heterojunction structure is formed between the N-type superlattice barrier layer 12 and the P-type superlattice barrier layer 14 and the superlattice absorption layer 13. The N-type superlattice barrier layer 12 is a hole barrier layer, and the P-type superlattice barrier layer 14 is an electron barrier layer.

[0058] Further, for the electron-hole pairs generated by the photocurrent formed at the superlattice absorption layer 13, the electrons are collected by the N-type contact layer 11 after passing through the N-type superlattice barrier layer 12, and the holes are collected by the P-type contact layer 15 after passing through the P-type superlattice barrier layer 14. The electrons thermally excited in the superlattice absorption layer 13 are blocked by the electron barrier of the P-type superlattice barrier layer 14, and the thermally excited holes are blocked by the hole barrier of the N-type superlattice barrier layer 12, so that the dark current of the detector is suppressed. That is to say, the double heterojunction structure can suppress the dark current and noise of the infrared detector, and at the same time ensure the normal absorption of the photocurrent, thereby improving the detection performance of the infrared detector.

[0059] In the infrared detector according to the embodiment of the present invention, the InPSb / GaSb superlattice can be used as both the electron barrier layer and the hole barrier layer of the InAs / GaSb or InAs / InAsSb superlattice to form the double heterojunction structure, and only the thickness ratio of the InPSb / GaSb superlattice needs to be adjusted. Taking the superlattice absorption layer 13 as the InAs / GaSb superlattice as an example to illustrate its physical mechanism.

[0060] Figure 3 is the conduction band E C and valence band E V in the InAs / GaSb superlattice absorption layer, the N-type InPSb / GaSb superlattice barrier layer, and the P-type InPSb / GaSb superlattice barrier layer in the infrared detector according to the embodiment of the present invention

[0061] InAs and GaSb form a type-II energy band arrangement, and the conduction band E C and valence band E V of the effective bandwidth after forming the miniband are as Figure 3 shown. The P-type superlattice barrier layer 14 is composed of the InPSb / GaSb superlattice, where the valence band E V position of the InPSb material is similar to that of InAs, while the conduction band E C is about 0.2 eV higher than that of InAs. Therefore, after InPSb and GaSb form a superlattice, assuming that the thickness of InPSb is the same as the thickness of InAs in the InAs / GaSb superlattice, and the thickness of GaSb is the same as the thickness of GaSb in the InAs / GaSb superlattice, then the valence band E V of the InPSb / GaSb superlattice miniband is flush with the valence band E V of the InAs / GaSb superlattice, and the conduction band E C of the superlattice miniband will be higher than the conduction band E C, thus forming a very perfect electron barrier layer.

[0062] For the N-type superlattice barrier layer 12, it is necessary to increase the proportion of InPSb in the InPSb / GaSb superlattice and decrease the proportion of GaSb. At this time, the conduction band E of the superlattice miniband C sharply drops, and it can reach the state flush with the conduction band E of the InAs / GaSb superlattice C , while the valence band E of the superlattice miniband V must be lower than the valence band E of the InAs / GaSb superlattice V .

[0063] Therefore, through material engineering and energy band engineering, the InPSb / GaSb superlattice realizes a perfect electron barrier layer and hole barrier layer for the InAs / GaSb superlattice, greatly simplifying the design and production difficulties. As an electron barrier, its barrier height is higher than that of the traditional InAs / GaSb superlattice electron barrier. In addition, the InPSb / GaSb superlattice does not contain Al, which can reduce the difficulty of material growth and processing compared with the existing technology solutions, and improve the stability and reliability of the production of infrared detectors. The material based on the InPSb / GaSb superlattice can be used as the electron barrier layer and hole barrier layer of short-wave, medium-wave and long-wave infrared detectors, and is suitable for infrared detectors of various wavelengths, with strong versatility.

[0064] The manufacturing process of the infrared detector according to the embodiment of the present invention will be described in detail below. Figures 4a to 4d It is a process diagram of the manufacturing method of the infrared detector according to the embodiment of the present invention.

[0065] Referring to Figure 4a , a substrate 10 is provided. In one example, the substrate 10 can be an N-type InAs substrate or an N-type GaSb substrate.

[0066] Referring to Figure 4b , an N-type contact layer 11, an N-type superlattice barrier layer 12, a superlattice absorption layer 13, a P-type superlattice barrier layer 14, and a P-type contact layer 15 are sequentially grown on the substrate 10 from bottom to top (i.e., stacked in sequence).

[0067] In one example, a metalorganic chemical vapor deposition (MOCVD) process can be used to sequentially grow an N-type contact layer 11, an N-type superlattice barrier layer 12, a superlattice absorption layer 13, a P-type superlattice barrier layer 14, and a P-type contact layer 15 from bottom to top on the substrate 10. Specifically, taking the metalorganic chemical vapor deposition process as the growth process, the growth sources are TMGa, TMIn, TMSb, AsH3, and PH3, the n-type doping source is SiH4, the p-type doping source is DEZn, the growth temperature is set at about 600 °C, and the reaction chamber pressure is set at 200 Torr. After removing the impurities on the surface of the substrate 10 in the high-temperature treatment removal step S1, the following are sequentially grown on the substrate 10 from bottom to top:

[0068] (1) N-type contact layer 11. In one example, the N-type contact layer 11 is an N-type InAs material with a thickness of 0.5 μm, doped with Si, and the doping concentration is 1×10 19 cm -3 , and the corresponding bandwidth is 0.3 eV.

[0069] (2) N-type superlattice barrier layer 12. In one example, the N-type superlattice barrier layer 12 is an N-type InPSb / GaSb superlattice with a thickness of 0.5 μm, doped with Si, and the doping concentration is 5×10 18 cm -3 , and the corresponding bandwidth is 0.4 eV, and its conduction band is flush with the conduction band of the superlattice absorption layer 13.

[0070] (3) Superlattice absorption layer 13. In one example, the superlattice absorption layer 13 is an InAs / GaSb superlattice with a thickness of 5 μm, unintentionally doped, and the corresponding bandwidth is 0.1 eV.

[0071] (4) P-type superlattice barrier layer 14. In one example, the P-type superlattice barrier layer 14 is a P-type InPSb / GaSb superlattice with a thickness of 0.5 μm, doped with Zn, and the doping concentration is 5×10 18 cm -3 , and the corresponding bandwidth is 0.3 eV, and its valence band is flush with the valence band of the superlattice absorption layer 13.

[0072] (5) P-type contact layer 15. In one example, the P-type contact layer 15 is a P-type GaAsSb material with a thickness of 0.2 μm, doped with Zn, and the doping concentration is 1×10 19 cm -3 , and the corresponding bandwidth is 0.6 eV.

[0073] In another example, a molecular beam epitaxy process (MBE process) can be used as the growth process. The growth sources are solid elemental sources Ga, In, As, P, and Sb, the n-type doping source is Si, the p-type doping source is Be, and the growth temperature is about 400 °C. After the substrate 10 is degassed and purified, the following layers are grown on the substrate 10 from bottom to top:

[0074] (1) N-type contact layer 11. In one example, the N-type contact layer 11 is an N-type InAsSb material with a thickness of 0.2 μm, doped with Si, and the doping concentration is 2×10 18 cm -3 , and the corresponding bandwidth is 0.3 eV.

[0075] (2) N-type superlattice barrier layer 12. In one example, the N-type superlattice barrier layer 12 is an N-type InPSb / GaSb superlattice with a thickness of 0.2 μm, doped with Si, and the doping concentration is 1×10 18 cm -3 , and the corresponding bandwidth is 0.5 eV. Its conduction band is flush with the conduction band of the superlattice absorption layer 13;

[0076] (3) Superlattice absorption layer 13. In one example, the superlattice absorption layer 13 is an InAs / InAsSb superlattice with a thickness of 2 μm, unintentionally doped, and the corresponding bandwidth is 0.25 eV.

[0077] (4) P-type superlattice barrier layer 14. In one example, the P-type superlattice barrier layer 14 is a P-type InPSb / GaSb superlattice with a thickness of 0.2 μm, doped with Be, and the doping concentration is 1×10 18 cm -3 , and the corresponding bandwidth is 0.4 eV. Its valence band is flush with the valence band of the superlattice absorption layer 13.

[0078] (5) P-type contact layer 15. In one example, the P-type contact layer 15 is a P-type GaSb material with a thickness of 0.1 μm, doped with Be, and the doping concentration is 2×10 18 cm -3 , and the corresponding bandwidth is 0.7 eV.

[0079] Referring to Figure 4c , local etching is performed on the P-type contact layer 15, the P-type superlattice barrier layer 14, the superlattice absorption layer 13, and the N-type superlattice barrier layer 12 to form a mesa structure A that exposes the N-type contact layer 11.

[0080] In one example, an inductively coupled plasma etching (ICP) process can be used to locally etch the P-type contact layer 15, the P-type superlattice barrier layer 14, the superlattice absorption layer 13, and the N-type superlattice barrier layer 12, exposing the N-type contact layer 11, thereby forming mesa structure A.

[0081] Referring to Figure 4d , a first electrode 16 is deposited on the N-type contact layer 11, and a second electrode 17 is deposited on the P-type contact layer 15.

[0082] In one example, an electron beam evaporation process can be used to deposit the first electrode 16 on the exposed N-type contact layer 11 and deposit the second electrode 17 on the P-type contact layer 15. In one example, both the first electrode 16 and the second electrode 17 are a combination of Ti (with a thickness of ) / Pt (with a thickness of ) / Au (with a thickness of ).

[0083] In another example, an electron beam evaporation process can be used to deposit the first electrode 16 on the exposed N-type contact layer 11 and deposit the second electrode 17 on the P-type contact layer 15. In another example, both the first electrode 16 and the second electrode 17 are a combination of Ti (with a thickness of ) / Pt (with a thickness of ) / Au (with a thickness of ).

[0084] In one example, the MOCVD process is used as the growth process for the N-type contact layer 11, the N-type superlattice barrier layer 12, the superlattice absorption layer 13, the P-type superlattice barrier layer 14, and the P-type contact layer 15, which can reduce costs and improve the cost performance of the fabricated infrared detector. The cut-off wavelength of the superlattice absorption layer 13 obtained by the specific process and parameters of the above MOCVD is about 12 μm, belonging to long-wave infrared, and the overall process flow is more suitable for fabricating long-wave focal plane detector arrays.

[0085] In another example, the MBE process is used as the growth process for the N-type contact layer 11, the N-type superlattice barrier layer 12, the superlattice absorption layer 13, the P-type superlattice barrier layer 14, and the P-type contact layer 15. The cut-off wavelength of the superlattice absorption layer 13 obtained by the above MBE process and parameters is about 5 μm, belonging to mid-wave infrared. Since the MBE process can form a steep interface, the performance of the obtained mid-wave infrared detector is relatively high.

[0086] In summary, according to the infrared detector and its manufacturing method provided by the embodiments of the present invention, a brand-new InPSb / GaSb superlattice is adopted. When the proportion of InPSb is relatively low, the InPSb / GaSb superlattice can be flush with the valence band of the InAs / GaSb superlattice or the InAs / InAsSb superlattice to achieve an electron barrier; while when the proportion of GaSb is relatively low, the InPSb / GaSb superlattice can be flush with the conduction band of the InAs / GaSb superlattice or the InAs / InAsSb superlattice to achieve a hole barrier. In this way, the InPSb / GaSb superlattice realizes a perfect electron barrier layer and hole barrier layer for the InAs / GaSb superlattice or the InAs / InAsSb superlattice, greatly simplifying the design and production difficulties. In addition, when the InPSb / GaSb superlattice is used as an electron barrier, the barrier height it provides is higher than that of the traditional InAs / GaSb superlattice electron barrier. Further, the InPSb / GaSb superlattice does not contain Al. Compared with the prior art solutions, the formed barrier layer is not easily oxidized, which can reduce the difficulty of material growth and processing, and improve the stability and reliability of the production of infrared detectors. Furthermore, the material based on the InPSb / GaSb superlattice can be used as an electron barrier layer and a hole barrier layer for short-wave, medium-wave, and long-wave infrared detectors, and is applicable to infrared detectors of various wavelengths, with strong versatility.

[0087] As used throughout this specification, the terms "exemplary", "example", etc. mean "serving as an example, instance, or illustration", and do not mean "preferred" or "advantageous" over other embodiments. For the purpose of providing an understanding of the described technology, the detailed description includes specific details. However, these technologies can be implemented without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described embodiments.

[0088] The optional embodiments of the embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0089] The foregoing description of the content of this specification is provided to enable any person of ordinary skill in the art to make or use the content of this specification. Various modifications to the content of this specification will be apparent to persons of ordinary skill in the art, and the general principles defined herein can be applied to other variations without departing from the scope of protection of the content of this specification. Therefore, the content of this specification is not limited to the examples and designs described herein, but is consistent with the broadest scope that conforms to the principles and novel features disclosed herein.

Claims

1. An infrared detector, characterized in that, The infrared detector includes: a substrate (10), an N-type contact layer (11), an N-type superlattice barrier layer (12), a superlattice absorption layer (13), a P-type superlattice barrier layer (14), a P-type contact layer (15), a first electrode (16), and a second electrode (17); Wherein, the N-type contact layer (11), the N-type superlattice barrier layer (12), the superlattice absorption layer (13), the P-type superlattice barrier layer (14), and the P-type contact layer (15) are sequentially stacked on the substrate (10), the first electrode (16) is disposed on the N-type contact layer (11), the second electrode (17) is disposed on the P-type contact layer (15), and the P-type superlattice barrier layer (14) of the infrared detector is a P-type InPSb / GaSb superlattice.

2. The infrared detector according to claim 1, characterized in that, The N-type superlattice barrier layer (12) of the infrared detector is an N-type InPSb / GaSb superlattice.

3. The infrared detector according to claim 1 or 2, wherein, The effective bandwidth of the N-type superlattice barrier layer (12) is greater than the effective bandwidth of the superlattice absorption layer (13), and the conduction band of the N-type superlattice barrier layer (12) is flush with the conduction band of the superlattice absorption layer (13); And / or, the effective bandwidth of the P-type superlattice barrier layer (14) is greater than the effective bandwidth of the superlattice absorption layer (13), and the valence band of the P-type superlattice barrier layer (14) is flush with the valence band of the superlattice absorption layer (13).

4. An infrared detector, characterized in that, The infrared detector includes: a substrate (10), an N-type contact layer (11), an N-type superlattice barrier layer (12), a superlattice absorption layer (13), a P-type superlattice barrier layer (14), a P-type contact layer (15), a first electrode (16), and a second electrode (17); Wherein, the N-type contact layer (11), the N-type superlattice barrier layer (12), the superlattice absorption layer (13), the P-type superlattice barrier layer (14), and the P-type contact layer (15) are sequentially stacked on the substrate (10), the first electrode (16) is disposed on the N-type contact layer (11), the second electrode (17) is disposed on the P-type contact layer (15), and the N-type superlattice barrier layer (12) of the infrared detector is an N-type InPSb / GaSb superlattice.

5. The infrared detector according to claim 4, wherein, The effective bandwidth of the N-type superlattice barrier layer (12) is greater than the effective bandwidth of the superlattice absorption layer (13), and the conduction band of the N-type superlattice barrier layer (12) is flush with the conduction band of the superlattice absorption layer (13); And / or, the effective bandwidth of the P-type superlattice barrier layer (14) is greater than the effective bandwidth of the superlattice absorption layer (13), and the valence band of the P-type superlattice barrier layer (14) is flush with the valence band of the superlattice absorption layer (13).

6. A method for manufacturing an infrared detector, characterized in that, The manufacturing method includes: Fabricating an N-type contact layer (11) on the substrate (10); Fabricating an N-type superlattice barrier layer (12) on the N-type contact layer (11); A superlattice absorption layer (13) is fabricated on the N-type superlattice barrier layer (12). A P-type superlattice barrier layer (14) is fabricated on the superlattice absorption layer (13) by using a P-type InPSb / GaSb superlattice. A P-type contact layer (15) is fabricated on the P-type superlattice barrier layer (14). A first electrode (16) is formed to contact the N-type contact layer (11), and a second electrode (17) is deposited on the P-type contact layer (15).

7. The manufacturing method of the infrared detector according to claim 6, wherein The fabricating the N-type superlattice barrier layer (12) on the N-type contact layer (11) includes: fabricating the N-type superlattice barrier layer (12) on the N-type contact layer (11) by using an N-type InPSb / GaSb superlattice.

8. The method for fabricating an infrared detector according to claim 6 or 7, wherein the effective bandwidth of the N-type superlattice barrier layer (12) is greater than that of the superlattice absorption layer (13), and the conduction band of the N-type superlattice barrier layer (12) is flush with the conduction band of the superlattice absorption layer (13); and / or, the effective bandwidth of the P-type superlattice barrier layer (14) is greater than that of the superlattice absorption layer (13), and the valence band of the P-type superlattice barrier layer (14) is flush with the valence band of the superlattice absorption layer (13).

9. A manufacturing method of an infrared detector, characterized in that, The fabrication method includes: fabricating an N-type contact layer (11) on a substrate (10); fabricating an N-type superlattice barrier layer (12) on the N-type contact layer (11) by using an N-type InPSb / GaSb superlattice; fabricating a superlattice absorption layer (13) on the N-type superlattice barrier layer (12); fabricating a P-type superlattice barrier layer (14) on the superlattice absorption layer (13); fabricating a P-type contact layer (15) on the P-type superlattice barrier layer (14); forming a first electrode (16) to contact the N-type contact layer (11), and depositing a second electrode (17) on the P-type contact layer (15).

10. The method for fabricating an infrared detector according to claim 9, wherein the effective bandwidth of the N-type superlattice barrier layer (12) is greater than that of the superlattice absorption layer (13), and the conduction band of the N-type superlattice barrier layer (12) is flush with the conduction band of the superlattice absorption layer (13); and / or, the effective bandwidth of the P-type superlattice barrier layer (14) is greater than that of the superlattice absorption layer (13), and the valence band of the P-type superlattice barrier layer (14) is flush with the valence band of the superlattice absorption layer (13).

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