Dual-color infrared detector and its manufacturing method

Abstract

The present invention discloses a dual-color infrared detector, which comprises a mid-wavelength infrared detector and a long-wavelength infrared detector arranged in a stacked manner. The mid-wave channel absorption layer of the mid-wavelength infrared detector is a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice, the long-wave channel absorption layer of the long-wavelength infrared detector is a P-type InAs / GaSb superlattice, and the mid-wave channel barrier layer of the mid-wavelength infrared detector and the long-wave channel barrier layer of the long-wavelength infrared detector are both N-type InPSb / InAs superlattices. The present invention also discloses a manufacturing method of the dual-color infrared detector. The mid-wave channel absorption layer of the dual-color infrared detector of the present invention adopts an InAs / InAsSb or InAsP / InAsSb superlattice, and the long-wave channel absorption layer adopts an InAs / GaSb superlattice, thus ensuring the best performance of the devices in each waveband.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and more particularly, relates to a dual-color infrared detector and a manufacturing method thereof. 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 type-II superlattice (InAs / GaSb or 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 the long-wave very long-wave band; compared with quantum well infrared detectors (QWIP), it has higher quantum efficiency, lower dark current, and simpler process. Currently, antimonide type-II superlattice infrared detectors have been industrialized.

[0003] In addition, in the long-wavelength detection band (8 - 12 μm), InAs / GaSb superlattice is basically used as the absorption region in the mature antimonide superlattice device structure because it is easy to find a heterostructure that matches it and has a large absorption coefficient in the long-wave band. In the mid-wavelength detection band (3 - 5 μm), the currently best-performing detectors use InAs / InAsSb superlattice because in the mid-wave band, compared with InAs / GaSb superlattice, InAs / InAsSb superlattice has a larger absorption coefficient and longer minority carrier lifetime.

[0004] Dual-color detectors that can simultaneously detect information in two infrared bands are more attractive. Dual-color detectors can obtain the absolute temperature of the target, suppress background interference, increase the detection and recognition distance, and reduce the false alarm rate. Dual-color infrared detectors generally adopt the form of two PN junctions placed back-to-back, with each PN junction corresponding to an absorption band. One band works under forward bias, and the other band works under reverse bias. For dual-color detectors that can simultaneously detect mid-wavelength and long-wavelength signals, InAs / GaSb superlattice is currently used as the absorption region. However, such a structure will cause the performance of the dual-color detector in detecting the mid-wave to not reach the best. Summary of the Invention

[0005] To solve the above technical problems existing in the prior art, the present invention provides a dual-color infrared detector and a manufacturing method thereof, in which the mid-wave channel absorption layer is made of P-type InAs / InAsSb superlattice or P-type InAsP / InAsSb superlattice instead of InAs / GaSb superlattice.

[0006] A dual-color infrared detector provided according to one aspect of an embodiment of the present invention includes a mid-wavelength infrared detector and a long-wavelength infrared detector stacked. The mid-wave channel absorption layer of the mid-wavelength infrared detector is a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice. The long-wave channel absorption layer of the long-wavelength infrared detector is a P-type InAs / GaSb superlattice. The mid-wave channel barrier layer of the mid-wavelength infrared detector and the long-wave channel barrier layer of the long-wavelength infrared detector are both N-type InPSb / InAs superlattices.

[0007] In an example of the dual-color infrared detector provided in the above aspect, the mid-wavelength infrared detector further includes a mid-wave channel contact layer and a mid-wave channel connection layer. The mid-wave channel absorption layer, the mid-wave channel barrier layer, and the mid-wave channel connection layer are sequentially stacked on the mid-wave channel contact layer. The long-wavelength infrared detector further includes: a long-wave channel connection layer and a long-wave channel contact layer. The long-wave channel connection layer, the long-wave channel barrier layer, the long-wave channel absorption layer, and the long-wave channel contact layer are sequentially stacked on the mid-wave channel connection layer. The infrared dual-color detector further includes: a first electrode and a second electrode. The first electrode is disposed on the mid-wave channel contact layer, and the second electrode is disposed on the long-wave channel contact layer.

[0008] In an example of the dual-color infrared detector provided in the above aspect, the effective bandwidth of the mid-wave channel barrier layer is greater than the effective bandwidth of the mid-wave channel absorption layer, and the conduction band of the mid-wave channel barrier layer is flush with the conduction band of the mid-wave channel absorption layer.

[0009] In an example of the dual-color infrared detector provided in the above aspect, the effective bandwidth of the long-wave channel barrier layer is greater than the effective bandwidth of the long-wave channel absorption layer, and the conduction band of the long-wave channel barrier layer is flush with the conduction band of the long-wave channel absorption layer.

[0010] In an example of the dual-color infrared detector provided in the above aspect, the effective bandwidth of the mid-wave channel absorption layer is greater than the effective bandwidth of the long-wave channel absorption layer.

[0011] In an example of the dual-color infrared detector provided in the above aspect, the mid-wave channel contact layer of the mid-wavelength infrared detector is a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice. The mid-wave channel connection layer of the mid-wavelength infrared detector and the long-wave channel connection layer of the long-wavelength infrared detector are both N-type InPSb / InAs superlattices. The long-wave channel contact layer of the long-wavelength infrared detector is a P-type InAs / GaSb superlattice.

[0012] A method for fabricating a dual-color infrared detector provided according to another aspect of an embodiment of the present invention includes: fabricating a mid-wavelength infrared detector and a long-wavelength infrared detector in a stacked manner on a substrate; wherein, the method for fabricating the mid-wavelength infrared detector includes: fabricating a mid-wave channel absorption layer of the mid-wavelength infrared detector using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice, and fabricating a mid-wave channel barrier layer of the mid-wavelength infrared detector using an N-type InPSb / InAs superlattice; wherein, the method for fabricating the long-wavelength infrared detector includes: fabricating a long-wave channel barrier layer of the long-wavelength infrared detector using an N-type InPSb / InAs superlattice, and fabricating a long-wave channel absorption layer of the long-wavelength infrared detector using a P-type InAs / GaSb superlattice.

[0013] In an example of the method for manufacturing the dual-color infrared detector provided in the above-mentioned another aspect, before forming the middle-wave channel absorption layer by using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice, the method for manufacturing the middle-wavelength infrared detector further includes: forming the middle-wave channel contact layer of the middle-wavelength infrared detector on the substrate by using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice; forming the middle-wave channel absorption layer by using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice, specifically including: forming the middle-wave channel absorption layer on the middle-wave channel contact layer by using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice; forming the middle-wave channel barrier layer by using an N-type InPSb / InAs superlattice, specifically including: forming the middle-wave channel barrier layer on the middle-wave channel absorption layer by using an N-type InPSb / InAs superlattice; after forming the middle-wave channel barrier layer by using an N-type InPSb / InAs superlattice, the method for manufacturing the middle-wavelength infrared detector further includes: forming the middle-wave channel connection layer of the middle-wavelength infrared detector on the middle-wave channel barrier layer by using an N-type InPSb / InAs superlattice; before forming the long-wave channel barrier layer by using an N-type InPSb / InAs superlattice, the method for manufacturing the long-wavelength infrared detector further includes: forming the long-wave channel connection layer of the long-wavelength infrared detector on the middle-wave channel connection layer by using an N-type InPSb / InAs superlattice; forming the long-wave channel barrier layer by using an N-type InPSb / InAs superlattice, specifically including: forming the long-wave channel barrier layer on the long-wave channel connection layer by using an N-type InPSb / InAs superlattice; forming the long-wave channel absorption layer of the long-wavelength infrared detector by using a P-type InAs / GaSb superlattice, specifically including: forming the long-wave channel absorption layer on the long-wave channel barrier layer by using a P-type InAs / GaSb superlattice; after forming the long-wave channel absorption layer by using a P-type InAs / GaSb superlattice, the method for manufacturing the long-wavelength infrared detector further includes: forming the long-wave channel contact layer of the long-wavelength infrared detector on the long-wave channel absorption layer by using a P-type InAs / GaSb superlattice; the manufacturing method further includes: forming a first electrode on the middle-wave channel contact layer and forming a second electrode on the long-wave channel contact layer.

[0014] In an example of the method for manufacturing a dual-color infrared detector provided in the above-mentioned other aspect, the effective bandwidth of the barrier layer of the medium-wave channel is greater than the effective bandwidth of the absorption layer of the medium-wave channel, and the conduction band of the barrier layer of the medium-wave channel is flush with the conduction band of the absorption layer of the medium-wave channel; and / or, the effective bandwidth of the barrier layer of the long-wave channel is greater than the effective bandwidth of the absorption layer of the long-wave channel, and the conduction band of the barrier layer of the long-wave channel is flush with the conduction band of the absorption layer of the long-wave channel.

[0015] In an example of the method for manufacturing a dual-color infrared detector provided in the above-mentioned other aspect, the effective bandwidth of the absorption layer of the medium-wave channel is greater than the effective bandwidth of the absorption layer of the long-wave channel.

[0016] Beneficial effects: In the medium-wave channel absorption layer of the dual-color infrared detector of the present invention, InAs / InAsSb or InAsP / InAsSb superlattices are used, and in the long-wave channel absorption layer, InAs / GaSb superlattices are used, ensuring the best performance of the devices in each waveband. In addition, in the dual-color infrared detector and its manufacturing method according to the present invention, heterojunctions are used in both the medium-wave channel and the long-wave channel to suppress dark current. The barrier material is InPSb / InAs superlattice. Through energy band engineering, the InPSb / InAs superlattice can simultaneously serve as the hole barrier for InAs / InAsSb (or InAsP / InAsSb) superlattices and InAs / GaSb superlattices, reducing the design difficulty. Further, in the dual-color infrared detector and its manufacturing method according to the present invention, a PNP structure is adopted, with the heterojunction in the middle, and the absorption layer is placed on both sides of the N-type connection layer. The hole barrier includes a heterojunction barrier and a PN junction barrier, thereby maximizing the hole barrier and suppressing electrical crosstalk to the greatest extent. Description of the Drawings

[0017] 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:

[0018] Figure 1 is a schematic structural diagram of a dual-color infrared detector according to an embodiment of the present invention;

[0019] Figure 2 is a schematic energy band diagram of a dual-color infrared detector according to an embodiment of the present invention;

[0020] Figure 3 is a relative position comparison diagram of the conduction band E C and valence band E V of the InPSb / InAs superlattice, InAs / GaSb superlattice, and InAs / InAsSb superlattice respectively in the dual-color infrared detector according to an embodiment of the present invention;

[0021] Figures 4a to 4d It is a manufacturing flow chart of a dual-color infrared detector according to an embodiment of the present invention. Detailed implementation manners

[0022] 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 technicians in the art can understand various embodiments of the present invention and various modifications suitable for specific intended applications.

[0023] 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" mean "at least partially based on", "at least partially according to". Terms such as "embodiment", "an example", "one embodiment" and "an embodiment" mean "at least one embodiment". Terms such as "another embodiment", "another example", "another embodiment" and "yet another example" mean "at least one other embodiment". Terms such as "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.

[0024] 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, while other details of little relevance are omitted.

[0025] As described in the background art, the absorption regions of existing dual-color detectors all adopt InAs / GaSb superlattices, and such a structure will cause the performance of the dual-color detector for detecting medium waves not to reach the best. Therefore, to solve this problem, a dual-color infrared detector and its manufacturing method are provided according to an embodiment of the present invention. In this dual-color infrared detector, a medium-wavelength infrared detector and a long-wavelength infrared detector are stacked. The medium-wave channel absorption layer of the medium-wavelength infrared detector is a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice, the long-wave channel absorption layer of the long-wavelength infrared detector is a P-type InAs / GaSb superlattice, and the medium-wave channel barrier layer of the medium-wavelength infrared detector and the long-wave channel barrier layer of the long-wavelength infrared detector are both N-type InPSb / InAs superlattices.

[0026] Therefore, for the mid-wave channel absorption layer of the dual-color infrared detector according to the embodiments of the present invention, InAs / InAsSb or InAsP / InAsSb superlattice is adopted, and for the long-wave channel absorption layer, InAs / GaSb superlattice is adopted, thus ensuring the best performance of the devices in each waveband.

[0027] The following will describe the dual-color infrared detector according to the embodiments of the present invention with reference to the accompanying drawings. Figure 1 It is a schematic structural diagram of the dual-color infrared detector according to the embodiments of the present invention.

[0028] As shown in Figure 1 the figure, the structure of the dual-color infrared detector according to the embodiments of the present invention includes: a substrate 10, and a mid-wave channel contact layer 20, a mid-wave channel absorption layer 30, a mid-wave channel barrier layer 40, a mid-wave channel connection layer 50, a long-wave channel connection layer 60, a long-wave channel barrier layer 70, a long-wave channel absorption layer 80, a long-wave channel contact layer 90 that are sequentially stacked on the substrate 10, a first electrode 100 disposed on the mid-wave channel contact layer 20, and a second electrode 110 disposed on the long-wave channel contact layer 90. Among them, as an example, the mid-wave channel contact layer 20, the mid-wave channel absorption layer 30, the mid-wave channel barrier layer 40, and the mid-wave channel connection layer 50 constitute a mid-wavelength infrared detector, and the long-wave channel connection layer 60, the long-wave channel barrier layer 70, the long-wave channel absorption layer 80, and the long-wave channel contact layer 90 constitute a long-wavelength infrared detector.

[0029] In the dual-color infrared detector according to the embodiments of the present invention, the core technical solution is to adopt a P-type InAs / InAsSb or InAsP / InAsSb superlattice as the mid-wave channel absorption layer 30, a P-type InAs / GaSb superlattice as the long-wave channel absorption layer 80, and an N-type InPSb / InAs superlattice as the mid-wave channel barrier layer 40 and the long-wave channel barrier layer 70 respectively. In this case, the effective bandwidth of the mid-wave channel barrier layer 40 is greater than that of the mid-wave channel absorption layer 30, and the conduction band of the mid-wave channel barrier layer 40 is flush with the conduction band of the mid-wave channel absorption layer 30, that is, a hole barrier for the mid-wave channel is formed. And the effective bandwidth of the long-wave channel barrier layer 70 is greater than that of the long-wave channel absorption layer 80, and the conduction band of the long-wave channel barrier layer 70 is flush with the conduction band of the long-wave channel absorption layer 80, that is, a hole barrier for the long-wave channel is formed. In this way, both the mid-wave channel and the long-wave channel are of single heterojunction structure, which can better suppress the dark current and does not affect the absorption of the photocurrent. Specifically, reference can be made to Figure 2 the energy band schematic diagram of the dual-color infrared detector according to the embodiments of the present invention as shown in the figure.

[0030] In addition, from Figure 2It can be seen that since the N-type material is placed in the middle and the P-type absorption layers are placed on both sides, the hole barrier includes the heterojunction barrier and the PN junction barrier, thus maximizing the hole barrier and suppressing electrical crosstalk to the greatest extent.

[0031] Figure 3 is a diagram showing the relative positions of the conduction bands E C and valence bands E V of the InPSb / InAs superlattice, InAs / GaSb superlattice, and InAs / InAsSb superlattice in the dual-color infrared detector according to an embodiment of the present invention.

[0032] Referring to Figure 3 , it can be seen the relative positions of the conduction bands E C and valence bands E V of the InPSb / InAs superlattice, InAs / GaSb superlattice, and InAs / InAsSb superlattice, and the physical mechanism for forming the hole barrier. Since the valence bands E V of the InPSb material and the InAs material are naturally flush, and the valence band E V after the InPSb / InAs superlattice forms a miniband is much lower than the valence bands E V of the InAs / GaSb superlattice and the InAs / InAsSb superlattice; at the same time, the conduction band E C of the InPSb / InAs superlattice can be made flush with the conduction bands E C of the InAs / GaSb superlattice and the InAs / InAsSb superlattice by adjusting the thickness ratio of InPSb and InAs respectively, thereby achieving an ideal hole barrier for the mid-wave absorption layer and the long-wave absorption layer.

[0033] The manufacturing process of the dual-color infrared detector according to an embodiment of the present invention will be described in detail below. Figures 4a to 4d is a process diagram of the manufacturing method of the infrared detector according to an embodiment of the present invention.

[0034] Referring to Figure 4a , first, a substrate 10 is provided.

[0035] In one example, the substrate 10 is P-type GaSb or InAs. Preferably, the substrate 10 is P-type InAs, with a thickness that can be 500 μm and a doping concentration that can be 5×10 16 cm -3 . Additionally preferably, the substrate 10 is P-type GaSb, with a thickness that can be 500 μm and a doping concentration that can be 2×10 16 cm -3 .

[0036] Referring to Figure 4b, secondly, a mid-wave channel contact layer 20, a mid-wave channel absorption layer 30, a mid-wave channel barrier layer 40, a mid-wave channel connection layer 50, a long-wave channel connection layer 60, a long-wave channel barrier layer 70, a long-wave channel absorption layer 80, and a long-wave channel contact layer 90 are sequentially stacked on the substrate 10.

[0037] In one example, a metalorganic chemical vapor deposition (MOCVD) process is used as the growth process, and the growth sources are TMGa, TMIn, TMSb, AsH3, and PH3. The N-type doping source is SiH4, and the P-type doping source is DEZn. The growth temperature is about 600 °C, and the reaction chamber pressure is 200 Torr. After removing the impurities on the surface of the substrate 10 by high-temperature treatment, the following are sequentially grown and stacked on the substrate 10:

[0038] (1) The mid-wave channel contact layer 20. In one example, the mid-wave channel contact layer 20 is an InAsP / InAsSb superlattice with a bandwidth of 0.31 eV, a thickness of 0.2 μm to 0.5 μm, P-type doping, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 . Preferably, the thickness of the mid-wave channel contact layer 20 is 0.5 μm, the doping source is Zn, and the doping concentration is 1×10 19 cm -3 .

[0039] (2) The mid-wave channel absorption layer 30. The mid-wave channel absorption layer 30 is an InAs / InAsSb or InAsP / InAsSb superlattice with a bandwidth of 0.31 eV, a thickness of 2 μm to 5 μm, P-type doping, and a doping concentration of 1×10 15 cm -3 ~1×10 17 cm -3 . Preferably, the mid-wave channel absorption layer 30 is an InAsP / InAsSb superlattice with a thickness of 4 μm, the doping source is Zn, and the doping concentration is 5×10 16 cm -3 .

[0040] (3) The mid-wave channel barrier layer 40. The mid-wave channel barrier layer 40 is an InPSb / InAs superlattice with a bandwidth of 0.5 eV, the conduction band is flush with the mid-wave channel absorption layer 30, a thickness of 0.1 μm to 0.5 μm, P-type doping, and a doping concentration of 5×10 15 cm -3 ~5×10 16 cm -3 . Preferably, the thickness of the mid-wave channel barrier layer 40 is 0.5 μm, the doping source is Zn, and the doping concentration is 2×10 16 cm-3 。

[0041] (4) The medium-wave channel connection layer 50. The medium-wave channel connection layer 50 is an InPSb / InAs superlattice, with a bandwidth of 0.5 eV, a thickness of 0.2 μm to 0.5 μm, N-type doping, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 。Preferably, the thickness of the medium-wave channel connection layer 50 is 0.5 μm, the doping source is Si, and the doping concentration is 5×10 18 cm -3 。

[0042] (5) The long-wave channel connection layer 60. The long-wave channel connection layer 60 is an InPSb / InAs superlattice, with a bandwidth of 0.55 eV, a thickness of 0.2 μm to 0.5 μm, N-type doping, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 。Preferably, the thickness of the long-wave channel connection layer 60 is 0.5 μm, the doping source is Si, and the doping concentration is 5×10 18 cm -3 。

[0043] (6) The long-wave channel barrier layer 70. The long-wave channel barrier layer 70 is an InPSb / InAs superlattice, with a bandwidth of 0.55 eV, the conduction band being flush with the long-wave channel absorption layer 80, a thickness of 0.1 μm to 0.5 μm, P-type doping, and a doping concentration of 5×10 15 cm -3 ~5×10 16 cm -3 。Preferably, the thickness of the long-wave channel barrier layer 70 is 0.5 μm, the doping source is Zn, and the doping concentration is 2×10 16 cm -3 。

[0044] (7) The long-wave channel absorption layer 80. The long-wave channel absorption layer 80 is an InAs / GaSb superlattice, with a bandwidth of 0.1 eV, a thickness of 2 μm to 5 μm, P-type doping, and a doping concentration of 1×10 15 cm -3 ~1×10 17 cm -3 。Preferably, the thickness of the long-wave channel absorption layer 80 is 5 μm, the doping source is Zn, and the doping concentration is 5×10 16 cm -3 。

[0045] (8) Long - wave channel contact layer 90, the long - wave channel contact layer 90 is an InAs / GaSb superlattice, with a bandwidth of 0.1 eV, a thickness of 0.2 μm to 0.5 μm, P - type doping, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 . Preferably, the thickness of the long - wave channel contact layer 90 is 0.5 μm, the doping source is Zn, and the doping concentration is 1×10 19 cm -3 .

[0046] Here, the bandwidth of the mid - wave channel absorption layer is 0.31 eV, corresponding to a wavelength of 4 μm, and the bandwidth of the long - wave channel absorption layer is 0.1 eV, corresponding to a wavelength of 12 μm. Thus, the wavelength coverage range is relatively large. The growth uses the MOCVD process, which can reduce costs and improve cost - effectiveness. The overall process flow is more suitable for fabricating a focal plane detector array.

[0047] In another example, the molecular beam epitaxy process (MBE) is used as the growth process. The growth sources are solid elemental sources In, Ga, As, P, and Sb. The N - type doping source is Te, and the P - type doping source is Be. The growth temperature is about 400 °C. After removing impurities on the surface of the substrate 10 by high - temperature treatment, the following layers are sequentially grown on the substrate 10 in a stacked manner:

[0048] (1) Mid - wave channel contact layer 20. In one example, the mid - wave channel contact layer 20 is an InAsP / InAsSb superlattice, with a bandwidth of 0.25 eV, a thickness of 0.2 μm to 0.5 μm, P - type doping, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 . Preferably, the thickness of the mid - wave channel contact layer 20 is 0.2 μm, the doping source is Be, and the doping concentration is 1×10 18 cm -3

[0049] (2) Mid - wave channel absorption layer 30. The mid - wave channel absorption layer 30 is an InAs / InAsSb superlattice, with a bandwidth of 0.25 eV, a thickness of 2 μm to 5 μm, P - type doping, and a doping concentration of 1×10 15 cm -3 ~1×10 17 cm -3 . Preferably, the thickness of the mid - wave channel absorption layer 30 is 2 μm, the doping source is Be, and the doping concentration is 1×10 16 cm -3 .

[0050] (3) Medium-wave channel barrier layer 40. The medium-wave channel barrier layer 40 is an InPSb / InAs superlattice with a bandwidth of 0.4 eV. The conduction band is flush with the medium-wave channel absorption layer 30, with a thickness of 0.1 μm to 0.5 μm, P-type doped, and a doping concentration of 5×10 15 cm -3 ~5×10 16 cm -3 . Preferably, the thickness of the medium-wave channel barrier layer 40 is 0.1 μm, the doping source is Be, and the doping concentration is 1×10 16 cm -3 .

[0051] (4) Medium-wave channel connection layer 50. The medium-wave channel connection layer 50 is an InPSb / InAs superlattice with a bandwidth of 0.4 eV, a thickness of 0.2 μm to 0.5 μm, N-type doped, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 . Preferably, the thickness of the medium-wave channel connection layer 50 is 0.2 μm, the doping source is Te, and the doping concentration is 1×10 18 cm -3 .

[0052] (5) Long-wave channel connection layer 60. The long-wave channel connection layer 60 is an InPSb / InAs superlattice with a bandwidth of 0.5 eV, a thickness of 0.2 μm to 0.5 μm, N-type doped, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 . Preferably, the thickness of the long-wave channel connection layer 60 is 0.2 μm, the doping source is Te, and the doping concentration is 1×10 18 cm -3 .

[0053] (6) Long-wave channel barrier layer 70. The long-wave channel barrier layer 70 is an InPSb / InAs superlattice with a bandwidth of 0.5 eV. The conduction band is flush with the long-wave channel absorption layer 80, with a thickness of 0.1 μm to 0.5 μm, P-type doped, and a doping concentration of 5×10 15 cm -3 ~5×10 16 cm -3 . Preferably, the thickness of the long-wave channel barrier layer 70 is 0.1 μm, the doping source is Be, and the doping concentration is 1×10 16 cm -3 .

[0054] (7) Long-wave channel absorption layer 80. The long-wave channel absorption layer 80 is an InAs / GaSb superlattice with a bandwidth of 0.12 eV, a thickness of 2 μm to 5 μm, P-type doping, and a doping concentration of 1×10 15 cm -3 ~1×10 17 cm -3 . Preferably, the thickness of the long-wave channel absorption layer 80 is 2 μm, the doping source is Be, and the doping concentration is 1×10 16 cm -3 .

[0055] (8) Long-wave channel contact layer 90. The long-wave channel contact layer 90 is an InAs / GaSb superlattice with a bandwidth of 0.12 eV, a thickness of 0.2 μm to 0.5 μm, P-type doping, and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 . Preferably, the thickness of the long-wave channel contact layer 90 is 0.2 μm, the doping source is Be, and the doping concentration is 1×10 18 cm -3 .

[0056] Here, the bandwidth of the mid-wave channel absorption layer is 0.25 eV, corresponding to a wavelength of 5 μm, and the bandwidth of the long-wave channel absorption layer is 0.12 eV, corresponding to a wavelength of 10 μm, which is the standard mid-long wave dual-color detector band. Since the MBE process can form a steep interface, the performance of the dual-color infrared detector prepared in this embodiment is relatively high.

[0057] Refer to Figure 4c , then, locally etch the long-wave channel contact layer 90, long-wave channel absorption layer 80, long-wave channel barrier layer 70, long-wave channel connection layer 60, mid-wave channel connection layer 50, mid-wave channel barrier layer 40, and mid-wave channel absorption layer 30 to expose the mid-wave channel contact layer 20 to form the detector mesa structure A.

[0058] In one example, an inductively coupled plasma etching (ICP) process can be used to locally etch the long-wave channel contact layer 90, long-wave channel absorption layer 80, long-wave channel barrier layer 70, long-wave channel connection layer 60, mid-wave channel connection layer 50, mid-wave channel barrier layer 40, and mid-wave channel absorption layer 30 to expose the mid-wave channel contact layer 20 to form the detector mesa structure A.

[0059] Refer to Figure 4d , finally, form the first electrode 100 on the mid-wave channel contact layer 20 and form the second electrode 110 on the long-wave channel contact layer 90.

[0060] In one example, an electron beam evaporation process can be used to form a first electrode 100 on the mid-wave channel contact layer 20 and a second electrode 110 on the long-wave channel contact layer 90. In another example, both the first electrode 100 and the second electrode 110 are combinations. In yet another example, both the first electrode 100 and the second electrode 110 are combinations.

[0061] In summary, for the dual-color infrared detector and its manufacturing method according to the embodiments of the present invention, the mid-wave channel absorption layer all adopts InAs / InAsSb or InAsP / InAsSb superlattice, and the long-wave channel absorption layer adopts InAs / GaSb superlattice, ensuring the best performance of devices in each band. In addition, in the dual-color infrared detector and its manufacturing method according to the embodiments of the present invention, heterojunctions are adopted in both the mid-wave channel and the long-wave channel to suppress dark current, and the barrier material is InPSb / InAs superlattice. Through energy band engineering, InPSb / InAs superlattice can simultaneously serve as the hole barrier for InAs / InAsSb (or InAsP / InAsSb) superlattice and InAs / GaSb superlattice, reducing the design difficulty. Further, in the dual-color infrared detector and its manufacturing method according to the embodiments of the present invention, a PNP structure is adopted, with the heterojunction in the middle, and the absorption layer is placed on both sides of the N-type connection layer. The hole barrier includes a heterojunction barrier and a PN junction barrier, thereby maximizing the hole barrier and suppressing electrical crosstalk to the greatest extent.

[0062] 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.

[0063] 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.

[0064] The foregoing description of the content of this specification is provided to enable any ordinary person skilled in the art to implement or use the content of this specification. Various modifications to the content of this specification will be obvious to those of ordinary skill in the art, and the general principles defined herein can also 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. A manufacturing method of a dual-color infrared detector, characterized in that, The manufacturing method includes: fabricating a stacked mid-wavelength infrared detector and long-wavelength infrared detector on a substrate; Among them, the method of fabricating a stacked mid-wavelength infrared detector and long-wavelength infrared detector on a substrate includes the following steps: Step 1, fabricating a mid-wave channel contact layer on the substrate using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice; Step 2, fabricating a mid-wave channel absorption layer on the mid-wave channel contact layer using a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice; Step 3, fabricating a mid-wave channel barrier layer on the mid-wave channel absorption layer using an N-type InPSb / InAs superlattice; Step 4, fabricating a mid-wave channel connection layer on the mid-wave channel barrier layer using an N-type InPSb / InAs superlattice; Step 5, fabricating a long-wave channel connection layer on the mid-wave channel connection layer using an N-type InPSb / InAs superlattice; Step 6, fabricating a long-wave channel barrier layer on the long-wave channel connection layer using an N-type InPSb / InAs superlattice; Step 7, fabricating a long-wave channel absorption layer on the long-wave channel barrier layer using a P-type InAs / GaSb superlattice; Step 8, fabricating a long-wave channel contact layer on the long-wave channel absorption layer using a P-type InAs / GaSb superlattice; Step 9, fabricating a first electrode on the mid-wave channel contact layer and fabricating a second electrode on the long-wave channel contact layer.

2. The manufacturing method according to claim 1, characterized in that, The effective bandwidth of the mid-wave channel barrier layer is greater than the effective bandwidth of the mid-wave channel absorption layer, and the conduction band of the mid-wave channel barrier layer is flush with the conduction band of the mid-wave channel absorption layer; and / or, the effective bandwidth of the long-wave channel barrier layer is greater than the effective bandwidth of the long-wave channel absorption layer, and the conduction band of the long-wave channel barrier layer is flush with the conduction band of the long-wave channel absorption layer.

3. The manufacturing method according to claim 2, characterized in that, The effective bandwidth of the mid-wave channel absorption layer is greater than the effective bandwidth of the long-wave channel absorption layer.

4. A dual-color infrared detector formed by the manufacturing method according to any one of claims 1 to 3, characterized in that, The dual-color infrared detector includes a stacked mid-wavelength infrared detector and long-wavelength infrared detector. The mid-wave channel absorption layer of the mid-wavelength infrared detector is a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice. The long-wave channel absorption layer of the long-wavelength infrared detector is a P-type InAs / GaSb superlattice. The mid-wave channel barrier layer of the mid-wavelength infrared detector and the long-wave channel barrier layer of the long-wavelength infrared detector are both N-type InPSb / InAs superlattices.

5. The dual-color infrared detector according to claim 4, characterized in that, The mid-wavelength infrared detector further includes a mid-wave channel contact layer and a mid-wave channel connection layer. The mid-wave channel absorption layer, the mid-wave channel barrier layer, and the mid-wave channel connection layer are sequentially stacked on the mid-wave channel contact layer; The long-wavelength infrared detector further includes: a long-wave channel connection layer and a long-wave channel contact layer. The long-wave channel connection layer, the long-wave channel barrier layer, the long-wave channel absorption layer, and the long-wave channel contact layer are sequentially stacked on the mid-wave channel connection layer; The infrared dual-color detector further includes: a first electrode and a second electrode, where the first electrode is disposed on the medium-wave channel contact layer, and the second electrode is disposed on the long-wave channel contact layer.

6. The dual-color infrared detector according to claim 4 or 5, characterized in that, The effective bandwidth of the medium-wave channel barrier layer is greater than the effective bandwidth of the medium-wave channel absorption layer, and the conduction band of the medium-wave channel barrier layer is flush with the conduction band of the medium-wave channel absorption layer.

7. The dual-color infrared detector according to claim 6, wherein The effective bandwidth of the long-wave channel barrier layer is greater than the effective bandwidth of the long-wave channel absorption layer, and the conduction band of the long-wave channel barrier layer is flush with the conduction band of the long-wave channel absorption layer.

8. The dual-color infrared detector according to claim 7, wherein The effective bandwidth of the medium-wave channel absorption layer is greater than the effective bandwidth of the long-wave channel absorption layer.

9. The dual-color infrared detector according to claim 4 or 5, characterized in that, The medium-wave channel contact layer of the medium-wavelength infrared detector is a P-type InAs / InAsSb superlattice or a P-type InAsP / InAsSb superlattice. The medium-wave channel connection layer of the medium-wavelength infrared detector and the long-wave channel connection layer of the long-wavelength infrared detector are both N-type InPSb / InAs superlattices. The long-wave channel contact layer of the long-wavelength infrared detector is a P-type InAs / GaSb superlattice.

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