A GaN-based self-driven narrow-band photodetector with a double-gate control structure, a preparation method and application thereof

Abstract

The application discloses a GaN-based self-driven narrow-band photodetector with a double-gate control structure and a preparation method and application thereof, and belongs to the technical field of semiconductor photodetectors. The preparation method comprises the following steps: sequentially epitaxially growing a buffer layer, a first absorption layer, an insertion layer, a second absorption layer and a polarization layer on a substrate surface; etching along one side of the polarization layer until part of the second absorption layer is exposed, and part of the polarization layer is reserved on the second absorption layer; etching a middle part of the second absorption layer which is not covered by the polarization layer, and etching a groove in the middle of the second absorption layer; preparing a metal thin layer in the groove; preparing a Bragg reflector above the metal thin layer; preparing a first metal electrode above the polarization layer and a second metal electrode above the second absorption layer. The photodetector realizes low-noise self-driven operation, can effectively improve the light-dark suppression ratio and response sensitivity while realizing narrow-band detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor optoelectronic devices, and more particularly, to a GaN-based self-driven narrow-band photodetector with a double-gate control structure and a preparation method and application thereof. BACKGROUND

[0002] A photodetector is a device for converting optical signals into electrical signals, that is, a photon incident into the photodetector generates an electron-hole pair, and then an optical current is formed by the transport of photo-generated electrons and holes in the device under an applied bias to realize optical-electrical signal conversion. Photodetectors can be applied in the fields of optical communication, optical imaging, flame detection, biomedical detection, etc. according to their different detection wavebands.

[0003] To meet the needs of different market applications, various types of photodetectors such as metal-semiconductor-metal (MSM) photodetectors, PIN junction photodetectors, avalanche photodetectors (APD), surface plasmon resonance (SPR) photodetectors, etc. have been developed. Among them, the MSM photodetector is widely concerned due to its fast response speed, high sensitivity and simple production.

[0004] A conventional MSM photodetector with a symmetric structure includes a substrate, a buffer layer, an absorption layer and a metal electrode in sequence along the epitaxial growth direction. The main disadvantage of this structure is that the absorption layer detects a wide light-emitting waveband, the device has a large dark current, and small signal detection cannot be performed, so it cannot be applied in high-security optical communication, fluorescence detection, artificial vision, etc.

[0005] The prior art discloses a self-powered MSM type ZnO-based ultraviolet photodetector, which is used to solve the problems of low response of the MSM type ultraviolet detector, the need for an external power supply, and the inability to meet the bandpass response.

[0006] However, the above photodetector still has certain deficiencies in response and narrow-band detection, and needs to be further optimized. SUMMARY

[0007] The technical problem to be solved by the present application is to overcome the deficiencies of the existing metal-semiconductor-metal (MSM) photodetector, such as wide light-emitting waveband, high dark current and low response, and to provide a preparation method of a GaN-based self-driven narrow-band photodetector with a double-gate control structure. The prepared photodetector can realize wavelength detection in a specific narrow waveband range, and can improve the photocurrent, reduce the dark current, and also has a high response.

[0008] Another object of the present application is to provide a GaN-based self-driven narrow-band photodetector with a double-gate control structure.

[0009] Another purpose of the present application is to provide an application of a GaN-based self-driven narrow-band photodetector with a double-gate control structure.

[0010] The above-mentioned purposes of the present application are achieved by the following technical solutions.

[0011] The present application discloses a preparation method of a GaN-based self-driven narrow-band photodetector with a double-gate control structure, which comprises the following steps:

[0012] S1. sequentially epitaxially growing a buffer layer, a first absorption layer, an insertion layer, a second absorption layer and a polarization layer on a substrate surface;

[0013] S2. etching along one side of the polarization layer until part of the second absorption layer is exposed, and retaining part of the polarization layer on the second absorption layer;

[0014] S3. etching the middle part of the second absorption layer which is not covered by the polarization layer, and etching a groove in the middle of the second absorption layer;

[0015] S4. preparing a metal thin layer in the groove;

[0016] S5. preparing a Bragg reflector above the metal thin layer;

[0017] S6. preparing a first metal electrode above the polarization layer, and preparing a second metal electrode above the second absorption layer.

[0018] The present application utilizes GaN and its ternary compound material system as the absorption layer, and forms a double-gate control structure of a metal gate and a polarization gate formed by a metal thin layer / second absorption layer / insertion layer, thereby forming a negative polarization charge and a metal-semiconductor contact depletion region, regulating the depletion effect of the electrons in the absorption layer (regulating the distribution of the depletion electric field), regulating the carrier transport channel, and playing a good "pinch-off" role on the two-dimensional electron gas channel, effectively reducing the dark current of the device under no light condition, and adjusting the transport behavior of the background carriers and the photo-generated carriers in the detector, thereby significantly improving the photocurrent and responsivity, and improving the detection rate of the device.

[0019] The light absorption region of the detector of the present application is also provided with a distributed Bragg reflector (DBR) and a planar metal thin layer structure, when light waves are incident on the DBR / metal structure, the energy of the light waves can be converted into Tamm plasmons, thereby forming a standing wave at the interface, and the standing wave has a very narrow bandwidth, which can produce a significant field enhancement effect at the interface, and realizes the detection of a specific narrow-band range of wavelengths, thereby solving the limitation that the traditional detector cannot select a specific waveband for detection, and improving the response speed and sensitivity of the self-driven narrow-band detector.

[0020] The asymmetric polarization layer structure is formed by etching along one side of the polarization layer in step S2, and the polarization electric field generated by the asymmetric polarization layer structure is used to regulate the photogenerated carrier separation and transport in the absorption layer, so that low-noise self-driven operation is realized under the condition of no external voltage.

[0021] In conclusion, the low-noise self-driven operation is realized, the light dark suppression ratio and response sensitivity are effectively improved while narrow-band detection is realized.

[0022] In the specific embodiment, the substrate can be ultrasonically treated by acetone, alcohol and deionized water, and dried by nitrogen.

[0023] In the specific embodiment, in step S1, the buffer layer, the first absorption layer, the insertion layer, the second absorption layer and the polarization layer can be sequentially epitaxially grown on the substrate surface by a thin film epitaxial growth technology such as deposition, evaporation or sputtering, to obtain a basic epitaxial layer structure of the detector.

[0024] In the specific embodiment, in step S2, the polarization layer can be etched along one side by a photolithography and dry etching process, until part of the second absorption layer is exposed, to etch a device mesa with part of the second absorption layer exposed, and etch the polarization layer to leave the polarization layer in part of the surface area on the mesa, to make a locally distributed polarization layer structure.

[0025] In the specific embodiment, in step S3, the second absorption layer can be etched in the middle by a photolithography and dry etching process, to etch a groove in the middle of the second absorption layer.

[0026] In the specific embodiment, in step S4, a thin layer of metal can be evaporated in the groove by a thin film epitaxial growth technology such as deposition, evaporation or sputtering.

[0027] In the specific embodiment, in step S5, a Bragg reflector (DBR) covering the thin layer of metal can be made by a thin film epitaxial growth technology such as deposition, evaporation or sputtering, and a photolithography and stripping technology.

[0028] In the specific embodiment, in step S6, a first metal electrode and a second metal electrode can be made by a photolithography technology and a metal evaporation process.

[0029] Preferably, the material of the first absorption layer is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, and the component coefficients are 0≤x1<1 and 0≤x2<1; the thickness of the first absorption layer is 0.1 μm-1 μm.

[0030] The material of the second absorption layer is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, the coefficients of each component are 0≤x1≤1, 0≤x2≤1; the thickness of the second absorption layer is 0.9μm~4μm.

[0031] Preferably, the material of the insertion layer is In. y1 Ga 1-y1 N or Al y2 Ga 1-y2 N, the coefficients of each component are 0≤y1≤1, 0≤y2≤1, y1<x1,y2> x2, wherein the thickness of the insertion layer is 1nm to 50nm.

[0032] Preferably, the polarization layer is made of In. z1 Ga 1-z1 N or Al z2 Ga 1-z2 N, the coefficients of each component are 0≤z1≤1, 0≤z2≤1, z1<x1,z2> x2, wherein the thickness of the polarization layer is 5nm to 100nm.

[0033] Preferably, the metal thin layer is made of Ti, Au, Ag, Al or Ni, and the thickness of the metal thin layer is 1 nm to 120 nm.

[0034] Preferably, the DBR is made of SiO2 / MoS2, Al2O3 / TiO2, or SiO2 / TiO2 material. The number of cycles and the thickness of each layer need to be determined based on the center absorption wavelength of the DBR.

[0035] Preferably, the projected area of ​​the groove is 10% to 70% of the surface area of ​​the second absorption layer, and the depth of the groove is less than the thickness of the second absorption layer.

[0036] Preferably, the first metal electrode and the second metal electrode are made of Ti / Au, Ni / Au, Cr / Au, Ti / Al / Ni / Au or Ti / Al / Ti / Au, and the thickness of the first metal electrode is 10nm to 800nm; the thickness of the second metal electrode is 10nm to 800nm.

[0037] In a specific embodiment, the substrate is made of sapphire, SiC, Si, GaN, or AlN;

[0038] In a specific embodiment, the buffer layer is made of GaN or AlN and has a thickness of 1μm to 3μm.

[0039] The application also protects the GaN-based self-driven narrow-band photodetector with the double-gate control structure prepared by the preparation method of any one of the above.

[0040] The application also protects the application of the GaN-based self-driven narrow-band photodetector with the double-gate control structure in optical communication, fluorescence detection, artificial vision, optical imaging, flame detection and biomedical detection.

[0041] Due to optical communication, especially high-security optical communication, a specific narrow waveband can reduce interference and crosstalk, improve the selectivity and security of signals, enhance the anti-interference ability, and meet the needs of customized services and regulatory standards, thereby ensuring the clarity, reliability and security of communication. Therefore, it is particularly important to realize the detection of a specific narrow waveband range of wavelengths. For fluorescence detection, flame detection and biomedical detection, a specific narrow waveband can improve selectivity, reduce background interference and enhance signal-to-noise ratio, thereby improving the sensitivity and accuracy of detection. For artificial vision and optical imaging, a specific narrow waveband can improve the recognition accuracy of specific targets or features, reduce environmental interference, enhance the contrast and resolution of images, and thus realize more accurate and reliable visual perception in complex environments.

[0042] The operation process of the GaN-based self-driven narrow-band photodetector with the double-gate control structure and the preparation method thereof in the application is possessed by those skilled in the art, the raw materials involved therein can be obtained through general routes, the process is simple and reliable, has strong repeatability, low production cost, is suitable for industrial promotion, and can be applied to the field of narrow-band photodetection.

[0043] Compared with the prior art, the application has the following beneficial effects:

[0044] The application discloses a GaN-based self-driven narrow-band photodetector with a double-gate control structure and a preparation method thereof.

[0045] The photodetector of the application realizes low-noise self-driven operation, can effectively improve the photo-dark suppression ratio and response sensitivity while realizing narrow-band detection. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 A structure schematic diagram of the GaN-based self-driven narrow-band photodetector with the double-gate control structure of embodiment 1.

[0047] Figure 2 A schematic diagram of a standard MSM type UV detector structure in the prior art for Comparative Example 1.

[0048] Figure 3 A comparison of photocurrent and dark current for Example 1 and Comparative Example 1.

[0049] Figure 4 A comparison of responsivity for Example 1 and Comparative Example 1.

[0050] Wherein, 101. substrate, 102. buffer layer, 1031. first absorbing layer, 104. insertion layer, 1032. second absorbing layer, 105. metal thin layer, 106. polarization layer, 107. first metal electrode, 108. second metal electrode, 109. Bragg reflector. DETAILED DESCRIPTION

[0051] The application will be further described in conjunction with specific embodiments, but the embodiments do not limit the application in any form. Unless otherwise specified, the raw materials used in the embodiments of the application are commercially available raw materials.

[0052] The preparation methods involved include photolithography, etching, metal evaporation, etc., which are common operation processes, and the raw materials involved can be obtained by general methods.

[0053] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0054] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0055] In the present application, unless specifically defined otherwise and limited, the terms "mount", "connect", "connection", "fixed", and the like should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0056] In the present application, unless specifically defined otherwise and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be the first feature directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be the first feature directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0057] It should be noted that when an element is referred to as "fixed to" or "provided to" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not the only embodiment.

[0058] Embodiment 1

[0059] As shown in Figure 1 A GaN-based self-driven narrow-band photodetector with a double-gate control structure, the preparation method comprises the following steps:

[0060] S1. In the MOCVD reaction furnace, a buffer layer 102 is epitaxially grown on the surface of the substrate 101, the growth temperature is 1050℃, and the gas pressure is 50mbar, so as to filter the dislocation defects and release the stress generated by the lattice mismatch; continue to epitaxially grow the first absorption layer 1031, the insertion layer 104, the second absorption layer 1032 and the polarization layer 106, the growth temperature is 1050℃, and the gas pressure is 50mbar;

[0061] S2. By photoetching and dry etching process, etching along the right side of the polarization layer 106, to expose part of the second absorption layer 1032, and retain the left part of the polarization layer 106 on the second absorption layer 1032;

[0062] S3. Etching the middle part of the second absorption layer 1032 which is not covered by the polarization layer 106 by lithography and dry etching process, and etching a groove in the middle of the second absorption layer 1032;

[0063] S4. Depositing a thin metal layer 105 in the groove by e-beam evaporation process;

[0064] S5. Alternately epitaxially growing DBR layers 109 on the surface of the thin metal layer 105 in a PECVD reaction furnace, the growth temperature is 200℃ / 180℃, the gas pressure is 120Pa / 60Pa, and etching the DBR 109 by lithography and etching process to make the DBR 109 only remain above the thin metal layer 105;

[0065] S6. Preparing the first metal electrode 107 above the polarization layer 106 and the second metal electrode 108 above the second absorption layer 1032 on the right side of the groove by lithography and e-beam evaporation process.

[0066] The material of the substrate 101 is sapphire.

[0067] The material of the buffer layer 102 is AlN; the thickness is 2μm.

[0068] The material of the first absorption layer 1031 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the first absorption layer 1031 is 3μm;

[0069] The material of the second absorption layer 1032 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the second absorption layer 1032 is 1μm.

[0070] The projection area of the groove is 40% of the surface area of the second absorption layer 1032, the depth of the groove is 0.8um, which is less than the thickness of the second absorption layer 1032.

[0071] The material of the insertion layer 104 is Al y2 Ga 1-y2 N, the component coefficient is y2=0.2, i.e. Al 0.2 Ga 0.8 N; the thickness of the insertion layer 104 is 20nm.

[0072] The material of the thin metal layer 105 is Au, and the thickness of the thin metal layer 105 is 20nm.

[0073] The material of the polarization layer 106 is Al z2 Ga 1-z2 N, the component coefficient is z2=0.2, i.e. Al0.2 Ga 0.8 N, the thickness of the polarization layer 106 is 100 nm.

[0074] The material of the first metal electrode 107 and the second metal electrode 108 is Ni / Au, the thickness of the first metal electrode 107 is 100 nm; the thickness of the second metal electrode 108 is 100 nm.

[0075] The material of the DBR 109 is SiO2 / MoS2, Al2O3 / TiO2 or SiO2 / TiO2. The material of the DBR 109 is 8 pairs of Al2O3 / TiO2, wherein the thickness of each pair of Al2O3 / TiO2 is 30 nm and 22 nm respectively.

[0076] Embodiment 2

[0077] A GaN-based self-driven narrow-band photodetector with a double-gate control structure, which is different from Embodiment 1 in that the material and period of the DBR 109, which is composed of 5 pairs of SiO2 / TiO2, with thicknesses of 35 nm and 22 nm respectively.

[0078] Embodiment 3

[0079] A GaN-based self-driven narrow-band photodetector with a double-gate control structure, which is different from Embodiment 1 in that the material of the metal thin layer 105 is Ag, and the thickness is 100 nm.

[0080] Embodiment 4

[0081] A GaN-based self-driven narrow-band photodetector with a double-gate control structure, which is different from Embodiment 1 in that:

[0082] The material of the buffer layer 102 is AlN; the thickness is 1 μm.

[0083] The material of the first absorption layer 1031 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the first absorption layer 1031 is 3 μm;

[0084] The material of the second absorption layer 1032 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the second absorption layer 1032 is 1 μm.

[0085] The projected area of the groove is 40% of the surface area of the second absorption layer 1032, and the depth of the groove is 0.5 um, which is less than the thickness of the second absorption layer 1032.

[0086] The material of the insertion layer 104 is Al y2 Ga 1-y2N, each component coefficient is y2=0.2, i.e. Al 0.2 Ga 0.8 N, the thickness of the insertion layer 104 is 1 nm.

[0087] The material of the metal thin layer 105 is Au, and the thickness of the metal thin layer 105 is 10 nm.

[0088] The material of the polarization layer 106 is Al z2 Ga 1-z2 N, each component coefficient is z2=0.2, i.e. Al 0.2 Ga 0.8 N, the thickness of the polarization layer 106 is 5 nm.

[0089] The material of the first metal electrode 107 and the second metal electrode 108 is Ni / Au, the thickness of the first metal electrode 107 is 10 nm, and the thickness of the second metal electrode 108 is 10 nm.

[0090] The material of the DBR 109 is 8 pairs of Al2O3 / TiO2, wherein the thickness of each pair of Al2O3 / TiO2 is 30 nm and 22 nm respectively.

[0091] Embodiment 5

[0092] A GaN-based self-driven narrow-band photodetector with a double-gate control structure, which is different from embodiment 1 in that:

[0093] The material of the buffer layer 102 is AlN, and the thickness is 3 μm.

[0094] The material of the first absorption layer 1031 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the first absorption layer 1031 is 4 μm;

[0095] The material of the second absorption layer 1032 is Al x2 Ga 1-x2 N, x2=0, i.e. GaN; the thickness of the second absorption layer 1032 is 1 μm.

[0096] The projected area of the groove is 40% of the surface area of the second absorption layer 1032, and the depth of the groove is 0.8 um, which is less than the thickness of the second absorption layer 1032.

[0097] The material of the insertion layer 104 is Al y2 Ga 1-y2 N, each component coefficient is y2=0.2, i.e. Al 0.2 Ga 0.8 N, the thickness of the insertion layer 104 is 50 nm.

[0098] The metal thin layer 105 is made of Au and has a thickness of 120 nm.

[0099] The polarization layer 106 is made of Al. z2 Ga 1-z2 N, the coefficients of each component are z2 = 0.2, that is, Al 0.2 Ga 0.8 N, the polarization layer 106 has a thickness of 100 nm.

[0100] The first metal electrode 107 and the second metal electrode 108 are made of Ni / Au. The thickness of the first metal electrode 107 is 800 nm, and the thickness of the second metal electrode 108 is 800 nm.

[0101] The DBR109 is made of 8 pairs of Al2O3 / TiO2, with each pair of Al2O3 / TiO2 having a thickness of 30nm and 22nm, respectively.

[0102] Comparative Example 1

[0103] like Figure 2 As shown, an MSM-type ultraviolet detector comprises, from bottom to top, a substrate 101, a buffer layer 102, an absorption layer 103, a metal electrode 107, and a metal electrode 108, wherein the metal electrode 107 and the metal electrode 108 are located on the surface of the absorption layer 103.

[0104] The materials used in each layer are the same as in Example 1, and will not be described again here.

[0105] Result detection

[0106] The performance of the standard MSM-type ultraviolet detectors in the above embodiments and comparative examples was tested:

[0107] (1) Photocurrent and dark current: The test method is TCAD simulation within the voltage range of -10V to +10V. The unit is A / m.

[0108] The specific test results of Example 1 and Comparative Example 1 are shown in Table 1 below. Figure 3 As shown:

[0109] Table 1

[0110]

[0111] (2) Response sensitivity: The test method was TCAD simulation software. The unit is A / W.

[0112] The specific test results of Example 1 and Comparative Example 1 are shown in Table 2 below. Figure 4 As shown:

[0113] Table 2

[0114]

[0115]

[0116] From the above results, compared with Comparative Example 1, the polarization gate, metal gate and DBR structure in the detector of the present application embodiment realize the detection of specific 200-360 nm narrow band range of wavelengths, the dark current of the GaN-based self-driven narrow-band photodetector with double-gate control structure represented by the dotted line is significantly reduced compared with the standard MSM ultraviolet detector, which shows that the double-gate control structure plays a good "pinch-off" role on the two-dimensional electron gas channel under no light conditions, at the same time, the photocurrent of the GaN-based self-driven narrow-band photodetector with double-gate control structure is also significantly higher than that of the standard MSM ultraviolet detector, so the light-dark suppression ratio of the GaN-based self-driven narrow-band photodetector with double-gate control structure is greatly improved. The dark current of Example 1 is more than four orders of magnitude lower than that of Comparative Example 1, which is sufficient to show that the noise is low; and the asymmetry of the photocurrent under forward and reverse bias can well reflect the self-driven performance of the device. The design of the present application improves the responsivity and sensitivity of the detector, and at the same time realizes the low-noise self-driven operation, overcoming the limitations of traditional detectors in narrow-band photodetection.

[0117] In Example 2, through the precise matching of the period and material of the metal thin layer 105 and the DBR 109, according to the influence of the DBR reflector and optical transmission, and the common influence of the Tamm plasmon at the metal-semiconductor interface on the strong absorption of the waveband, high-intensity absorption of different narrow-band light-emitting wavebands can be realized.

[0118] The narrow-band photodetectors in the above embodiments can all be realized, and have a certain influence on the light-dark current of the detector. In addition, the effect of the narrow-band photodetector will be affected by the material, size and component changes of the first absorption layer, the second absorption layer, the insertion layer, the metal thin layer, the DBR layer and the polarization layer in the detector, so it is necessary to make appropriate optimization according to different device structures and process methods, so that the narrow-band photodetector can play the best effect.

[0119] The remaining matters of the present application are known technologies.

[0120] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principles of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for fabricating a GaN-based self-driven narrowband photodetector with a dual-gate control structure, characterized in that, The method comprises the following steps: S1. sequentially epitaxially growing a buffer layer (102), a first absorption layer (1031), an insertion layer (104), a second absorption layer (1032) and a polarization layer (106) on the surface of a substrate (101); S2. etching along one side of the polarization layer (106) to expose part of the second absorption layer (1032), and retaining part of the polarization layer (106) on the second absorption layer (1032); S3. etching the middle part of the second absorption layer (1032) not covered by the polarization layer (106) to form a groove in the middle of the second absorption layer (1032); S4. preparing a metal thin layer (105) in the groove; S5. preparing a Bragg reflector (109) above the metal thin layer (105); S6. preparing a first metal electrode (107) above the polarization layer (106) and a second metal electrode (108) above the second absorption layer (1032); The insertion layer (104) serves as a polarization gate. The metal thin layer (105) serves as a metal gate. The material of the first absorption layer (1031) is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, and the component coefficients are 0≤x1<1 and 0≤x2<1. The material of the second absorption layer (1032) is In x1 Ga 1-x1 N or Al x2 Ga 1-x2 N, and the component coefficients are 0≤x1<1 and 0≤x2<1. The material of the insertion layer (104) is In y1 Ga 1-y1 N or Al y2 Ga 1-y2 N, and the component coefficients are 0≤y1≤1, 0≤y2≤1, y1 The material of the polarization layer (106) is In z1 Ga 1-z1 N or Al z2 Ga 1-z2 N, and the component coefficients are 0≤z1≤1, 0≤z2≤1, z1 2. The fabrication method of the GaN-based self-driven narrowband photodetector with a dual-gate control structure as described in claim 1, characterized in that, The thickness of the first absorption layer (1031) is 0.9 μm-4 μm, and the thickness of the second absorption layer (1032) is 0.1 μm-1 μm.

3. The method of claim 2, wherein the method further comprises: depositing a first gate dielectric layer on the first gate electrode; depositing a second gate dielectric layer on the second gate electrode; and depositing a gate dielectric layer on the first and second gate electrodes. The thickness of the insertion layer (104) is 1 nm-50 nm.

4. The fabrication method of the GaN-based self-driven narrowband photodetector with a dual-gate control structure as described in claim 2, characterized in that, The thickness of the polarization layer (106) is 5 nm-100 nm.

5. The fabrication method of the GaN-based self-driven narrowband photodetector with a dual-gate control structure as described in claim 1, characterized in that, The material of the metal thin layer (105) is Ti, Au, Ag, Al or Ni, and the thickness of the metal thin layer (105) is 1 nm-120 nm.

6. The fabrication method of the GaN-based self-driven narrowband photodetector with a dual-gate control structure as described in claim 1, characterized in that, The material of the Bragg reflector (109) is SiO2 / MoS2, Al2O3 / TiO2 or SiO2 / TiO2.

7. The method for fabricating a GaN-based self-driven narrowband photodetector with a dual-gate control structure as described in claim 1, characterized in that, The projection area of the groove is 10%-70% of the surface area of the second absorption layer (1032), and the depth of the groove is less than the thickness of the second absorption layer (1032).

8. The method for fabricating a GaN-based self-driven narrowband photodetector with a dual-gate control structure as described in claim 1, characterized in that, The material of the first metal electrode (107) and the second metal electrode (108) is Ti / Au, Ni / Au, Cr / Au, Ti / Al / Ni / Au or Ti / Al / Ti / Au, the thickness of the first metal electrode (107) is 10 nm-800 nm, and the thickness of the second metal electrode (108) is 10 nm-800 nm.

9. The GaN-based self-driven narrow-band photodetector with a double-gate control structure prepared by the method of any one of claims 1-8.

10. The application of the GaN-based self-driven narrow-band photodetector with a double-gate control structure of claim 9 in optical communication, fluorescence detection, artificial vision, optical imaging, flame detection or biomedical detection.

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