A solar blind ultraviolet detector and a preparation method and application thereof

Abstract

The application discloses a kind of solar blind ultraviolet detectors and preparation method and application thereof, belong to semiconductor photoelectric detector technical field.Preparation method includes the following steps: sequentially epitaxial growth GaN buffer layer, AlGaN interlayer and GaN transport layer on substrate surface;Etching the upper surface of GaN transport layer, get groove;Depositing first insulating layer in groove;Epitaxial growth Ga2O3 absorption layer on GaN transport layer and first insulating layer, so that Ga2O3 absorption layer covers first insulating layer;Etching part Ga2O3 absorption layer to expose part of the upper surface of GaN transport layer;Exposed part of the upper surface of GaN transport layer is provided with anode electrode;Metal layer and cathode electrode are made on the upper surface of Ga2O3 absorption layer, so that cathode electrode and the upper surface of Ga2O3 absorption layer are directly contacted.The application solves the problem that photo-generated holes are accumulated in gallium oxide as an absorption layer, thereby reducing photocurrent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor photodetectors, and more particularly to a solar blind ultraviolet detector and a preparation method and application thereof. BACKGROUND

[0002] The light in the 200nm to 280nm band is absorbed by the ozone layer when the solar radiation passes through the ozone layer, and cannot reach the ground, so this band is called the solar blind band. Due to small background noise, the solar blind detector has been widely used in the fields of missile early warning, astronomy, chemical and biological analysis, space communication and fire monitoring. As a fourth-generation wide-bandgap semiconductor material, gallium oxide (Ga2O3) has a high bandgap of 4.8eV, and the corresponding maximum cutoff absorption wavelength is about 254nm, so Ga2O3 has natural solar blind detection characteristics. However, the defect density of the gallium oxide thin film is relatively high, which can cause a large dark current, resulting in a decrease in the signal-to-noise ratio and sensitivity of the detector. In addition, the carrier mobility of gallium oxide is relatively low, and the photo-generated carriers are prone to local congestion, resulting in poor photoelectric conversion efficiency, and thus causing the performance parameters such as the responsivity and external quantum efficiency of the detector to decrease.

[0003] In order to improve the performance of the Ga2O3-based ultraviolet detector, Chinese patent CN 114220878 A discloses a Ga2O3 / GaN solar blind ultraviolet detector with a carrier transport layer and a preparation method thereof. The patent uses the electric field formed by the Schottky contact between the metal and the gallium oxide to push the photo-generated electrons from the Ga2O3 / absorption layer with many defects into the GaN transport layer with few defects, so as to improve the responsivity and response speed of the detector. However, the above-mentioned prior art does not solve the problem of accumulation of photo-generated holes in the gallium oxide as an absorption layer, thereby reducing the photocurrent. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects and deficiencies that the existing solar blind ultraviolet detector with gallium oxide as an absorption layer is prone to cause accumulation of photo-generated holes, thereby reducing the photocurrent. The present application provides a preparation method of a solar blind ultraviolet detector, which realizes effective collection of photo-generated holes by setting a cathode electrode in direct contact on the Ga2O3 absorption layer, avoids accumulation of photo-generated holes in the Ga2O3 absorption layer and recombination with electrons, and at the same time uses the electric field formed by the contact between the Ga2O3 absorption layer and the metal layer to transport the carriers to the GaN transport layer, thereby improving the transport efficiency of the electrons and the photocurrent of the device.

[0005] Another object of the present application is to provide a solar blind ultraviolet detector.

[0006] Still another object of the present application is to provide an application of a solar blind ultraviolet detector.

[0007] The above object of the present application is achieved by the following technical solutions.

[0008] A preparation method of a solar blind ultraviolet detector, comprising the following steps:

[0009] S1. sequentially epitaxially growing a GaN buffer layer, an AlGaN insertion layer and a GaN transport layer on a substrate surface;

[0010] S2. etching an upper surface of the GaN transport layer to obtain a groove;

[0011] S3. depositing a first insulating layer in the groove;

[0012] S4. epitaxially growing a Ga2O3 absorption layer on the GaN transport layer and the first insulating layer, so that the Ga2O3 absorption layer covers the first insulating layer;

[0013] S5. etching part of the Ga2O3 absorption layer to expose part of the upper surface of the GaN transport layer;

[0014] S6. arranging an anode electrode on the exposed part of the upper surface of the GaN transport layer; and making a metal layer and a cathode electrode on an upper surface of the Ga2O3 absorption layer, so that the cathode electrode directly contacts the upper surface of the Ga2O3 absorption layer.

[0015] The present application discloses a solar blind ultraviolet detector with a photo-generated hole release effect, which has a Ga2O3 / GaN / AlGaN / GaN structure. The cathode electrode directly contacting the Ga2O3 absorption layer is arranged to effectively collect the photo-generated holes, so as to avoid the photo-generated holes from accumulating in the Ga2O3 absorption layer to recombine with the electrons. Meanwhile, the electric field formed by the contact between the Ga2O3 absorption layer and the metal layer is used to transport the carriers to the GaN transport layer with high electron mobility, so as to improve the transport efficiency of the electrons and the photocurrent of the device.

[0016] Moreover, the solar blind ultraviolet detector has negative polarization charges at the interface between the AlGaN insertion layer and the GaN transport layer. The groove region is formed on the upper surface of the GaN transport layer, and the depletion region formed in the groove region under the condition of no light can pinch off the transport channel of the electrons to reduce the dark current.

[0017] The operation process in the preparation method of the solar blind ultraviolet detector is possessed by the person skilled in the art, the raw materials involved can be obtained through general ways, 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 solar blind ultraviolet detection.

[0018] Preferably, the step S6 comprises the following steps:

[0019] An anode electrode is arranged on the upper surface of the exposed part of the GaN transmission layer;

[0020] A second insulating layer is epitaxially grown on the upper surface of the exposed part of the GaN transmission layer and the upper surface of the Ga2O3 absorption layer;

[0021] A metal layer is made on the upper surface of the second insulating layer;

[0022] A cathode electrode is made on the upper surface of the Ga2O3 absorption layer, so that the cathode electrode directly contacts the upper surface of the Ga2O3 absorption layer.

[0023] The second insulating layer functions to regulate the electric field in the Ga2O3 absorption layer and protect the Ga2O3 absorption layer from physical damage and chemical corrosion, thereby prolonging the service life of the detector.

[0024] Preferably, the projected area of the Ga2O3 absorption layer is 20% to 80% of the area of the upper surface of the GaN transmission layer.

[0025] The projected area of the Ga2O3 absorption layer is related to the responsivity of the solar blind ultraviolet detector, and a larger projected area can absorb more light, thereby having higher response characteristics in the solar blind band.

[0026] Preferably, the projected area of the recess in the GaN transmission layer is 5% to 30% of the surface area of the GaN transmission layer.

[0027] The projected area of the recess in the GaN transmission layer is related to the dark current of the solar blind ultraviolet detector, and a larger projected area forms a larger depletion region, and more electrons are depleted.

[0028] Preferably, the depth of the recess is 0.001 μm to 1 μm, the thickness of the first insulating layer is 0.001 μm to 0.5 μm, and the thickness of the first insulating layer is less than or equal to the depth of the recess.

[0029] Preferably, the projected area of the metal layer is 20% to 80% of the area of the upper surface of the Ga2O3 absorption layer.

[0030] The projected area of the metal layer is related to the photocurrent of the solar blind ultraviolet detector, and a larger projected area forms a larger depletion region between the metal layer and the Ga2O3 absorption layer, so that more electrons are pushed into the GaN transmission layer.

[0031] Preferably, the projected area of the second insulating layer is 20% to 80% of the area of the upper surface of the Ga2O3 absorption layer, and the thickness of the second insulating layer is 0.001 μm to 0.5 μm.

[0032] The projected area of the second insulating layer is related to the photocurrent of the solar blind ultraviolet detector, and the larger the projected area, the larger the corresponding deposited metal layer area, and the larger the depletion region formed with the Ga2O3absorption layer, so that more electrons are pushed into the GaN transport layer.

[0033] Preferably, the thickness of the GaN buffer layer is 1-3 μm, the thickness of the AlGaN insertion layer is 0.005-0.5 μm, the thickness of the GaN transport layer is 0.1-5 μm, the thickness of the Ga2O3absorption layer is 0.001-0.5 μm, and the thickness of the metal layer is 1-20 nm.

[0034] In the specific embodiment,

[0035] The material of the substrate is specifically a silicon wafer, sapphire or diamond.

[0036] The material of the AlGaN insertion layer is unintentionally doped AlGaN material, and the Al component ranges from 0.1 to 0.5.

[0037] The material of the GaN transport layer is unintentionally doped GaN material.

[0038] The material of the first insulating layer is one or more of Si3N4, SiO2, Al2O3, HfO2, Ta2O5, AlN and LiF.

[0039] The material of the Ga2O3absorption layer is undoped (unintentionally doped) Ga2O3.

[0040] The materials of the cathode electrode, the anode electrode and the metal layer are the same or different, and are Au, Ag, Ni, ITO, Ti or Pt.

[0041] The material of the metal layer can be a stack of several metals, for example, a stack of nickel and gold, i.e. a nickel layer-gold layer or a nickel layer-gold layer-nickel layer-gold layer.

[0042] The material of the second insulating layer is one or more of undoped SiO2, Al2O3, Si3N4, HfO2, Ta2O5, AlN, LiF, diamond or PMMA.

[0043] The pattern of the metal layer and the second insulating layer is a bar shape, a rectangular shape, a circular shape, a circular ring shape or a matrix distribution, and the shape of the second insulating layer corresponds to the shape of the metal layer one by one.

[0044] In step S1, the GaN buffer layer, the AlGaN insertion layer and the GaN transport layer are sequentially epitaxially grown on the surface of the substrate by thin film epitaxial growth techniques such as deposition, evaporation or sputtering.

[0045] In step S2, the groove is prepared by photolithography and dry etching process.

[0046] In step S3, the first insulating layer is prepared by thin film epitaxial growth technology of deposition, evaporation or sputtering, photolithography and wet etching.

[0047] In step S4, the Ga2O3 absorption layer is prepared by thin film epitaxial growth technology of deposition, evaporation or sputtering.

[0048] In step S5, part of the Ga2O3 absorption layer is etched by photolithography and dry etching to expose part of the upper surface of the GaN transmission layer.

[0049] In step S6, the anode electrode, the cathode electrode and the metal layer are prepared by photolithography and electron beam evaporation process.

[0050] In step S6, the second insulating layer is prepared by thin film epitaxial growth technology of deposition, evaporation or sputtering.

[0051] In step S6, the second insulating layer is prepared by photolithography and wet etching to form a pattern.

[0052] The application also protects the solar blind ultraviolet detector prepared by the preparation method of any one of the above.

[0053] The application also protects the application of the above-mentioned solar blind ultraviolet detector in fire monitoring, missile early warning, astronomy, chemical, biological analysis, space communication.

[0054] The solar blind ultraviolet detector can be applied to fire detection, because the solar blind ultraviolet detector is not easily disturbed by sunlight, and has strong processing ability for weak signals. The "solar blind" ultraviolet flame detector can timely and accurately capture the flame to make up for the hysteresis of the infrared flame detector and prevent the occurrence of fire.

[0055] The solar blind ultraviolet detector can be applied to missile early warning, because the solar blind ultraviolet detector is not easily disturbed by sunlight, and has high sensitivity and strong anti-interference ability. The "solar blind" ultraviolet missile early warning detector can timely and accurately capture the ultraviolet radiation released in the missile plume, make up for the shortcomings of other early warning systems, improve the accuracy and response speed of early warning, and effectively prevent the occurrence of missile threat.

[0056] The solar blind ultraviolet detector can be applied to astronomy, and the solar blind ultraviolet detector can timely and accurately capture the ultraviolet radiation from distant galaxies and celestial bodies to help scientists reveal the mystery of the universe.

[0057] The solar blind ultraviolet detector can be applied in chemistry due to its high sensitivity to specific ultraviolet bands, and can be used for detection and analysis of chemical substances. For example, it can be used to detect harmful chemical substances in the environment, such as ozone and nitrogen oxides, which have characteristic absorption in specific ultraviolet bands.

[0058] The solar blind ultraviolet detector can be applied in biological analysis, which can detect the luminescence or absorption characteristics of biological molecules in specific ultraviolet bands, which is crucial for analyzing the structure and function of biological molecules.

[0059] The solar blind ultraviolet detector can be applied in space communication, which has extremely low background noise and ultra-high signal-to-noise ratio in ultraviolet communication, and can realize high-security data transmission in space communication to prevent information from being eavesdropped and ensure the security of communication.

[0060] Compared with the prior art, the beneficial effects of the present application are:

[0061] The solar blind ultraviolet detector has a Ga2O3 / GaN / AlGaN / GaN structure, and the cathode electrode in direct contact is arranged on the Ga2O3 absorption layer to realize effective collection of photo-generated holes, avoid accumulation of photo-generated holes in the Ga2O3 absorption layer and recombination with electrons, and transport the carriers to the GaN transport layer with high electron mobility by using the electric field formed by the contact between the Ga2O3 absorption layer and the metal layer, thereby improving the transport efficiency of electrons and the photocurrent of the device. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 Figure 1 is a schematic diagram of the solar blind ultraviolet detector of Example 1 of the present application.

[0063] Figure 2 Figure 2 is a schematic diagram of the solar blind ultraviolet detector of Example 1 of the present application.

[0064] Figure 3 Figure 3 is a schematic diagram of the solar blind ultraviolet detector of Example 2 of the present application.

[0065] Figure 4 Figure 4 is a schematic diagram of the solar blind ultraviolet detector of Comparative Example 1 of the present application.

[0066] Figure 5 Figure 5 is the photo-generated hole concentration in the gallium oxide absorption layer of the solar blind ultraviolet detector of Example 1 and Comparative Example 1 of the present application.

[0067] Figure 6 Figure 6 is the photocurrent of the solar blind ultraviolet detector of Example 1 and Comparative Example 1 of the present application.

[0068] Wherein, 101. substrate, 102. GaN buffer layer, 103. AlGaN insertion layer, 104. GaN transport layer, 105. first insulating layer, 106. Ga2O3absorption layer, 107. metal layer, 108. cathode electrode, 109. anode electrode, 110. second insulating layer. DETAILED DESCRIPTION

[0069] The application will be further described in conjunction with the 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.

[0070] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "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 present 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 present application.

[0071] 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 present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0072] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. 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.

[0073] In the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "over", "above" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. The first feature is "under", "below" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0074] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there can be an intermediate element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not mean the only implementation.

[0075] Embodiment 1

[0076] As shown in the drawings, a solar blind ultraviolet detector, the preparation method comprises the following steps: Figures 1-2

[0077] S1. Epitaxially growing a GaN buffer layer 102, an AlGaN insertion layer 103 and a GaN transport layer 104 in sequence on the surface of a substrate 101;

[0078] S2. Etching the upper surface of the middle part of the GaN transport layer 104 to obtain a groove;

[0079] S3. Depositing a first insulating layer 105 in the groove;

[0080] S4. Epitaxially growing a Ga2O3 absorption layer 106 on the GaN transport layer 104 and the first insulating layer 105, so that the Ga2O3 absorption layer 106 completely covers the first insulating layer 105;

[0081] S5. Etching the right part of the Ga2O3 absorption layer 106 to expose the upper surface of part of the GaN transport layer 104;

[0082] S6. Setting an anode electrode 109 on the upper surface of the exposed part of the GaN transport layer 104; and making a metal layer 107 and a cathode electrode 108 on the upper surface of the Ga2O3 absorption layer 106, so that the cathode electrode 108 is in direct contact with the upper surface of the Ga2O3 absorption layer 106.

[0083] ​The upper surface of the middle part of the Ga2O3absorption layer 106 is covered with a patterned metal layer 107, and a cathode electrode 108 is on the left side of the upper surface of the Ga2O3absorption layer 106.

[0084] Specifically,

[0085] In step S1, a GaN buffer layer 102, an AlGaN insertion layer 103 and a GaN transport layer 104 are sequentially epitaxially grown on the surface of a substrate 101 in a MOCVD reaction furnace, and the growth temperature is 1050℃ and the gas pressure is 50mbar.

[0086] In step S2, the groove is prepared by a photolithography and dry etching process.

[0087] In step S3, a first insulating layer 105 is epitaxially grown in a PECVD reaction furnace, and the growth temperature is 300℃ and the gas pressure is 0.5mbar. The first insulating layer 105 on the surface of the GaN transport layer 104 is removed by photolithography and wet etching to prepare the first insulating layer 105 in the groove.

[0088] In step S4, the Ga2O3absorption layer is epitaxially grown in an ALD reaction furnace, and the growth temperature is 250℃.

[0089] In step S5, the Ga2O3absorption layer 106 is partially etched by photolithography and dry etching to expose part of the upper surface of the GaN transport layer 104 to form a mesa.

[0090] In step S6, the anode electrode, the cathode electrode and the metal layer are prepared by photolithography and electron beam evaporation processes.

[0091] The Ga2O3absorption layer 106 covers the first insulating layer 105.

[0092] The projected area of the Ga2O3absorption layer 106 is 60% of the area of the upper surface of the GaN transport layer 104.

[0093] The projected area of the groove in the GaN transport layer 104 is 20% of the surface area of the GaN transport layer 104.

[0094] The depth of the groove is 0.05μm.

[0095] The projected area of the metal layer 107 is 80% of the area of the upper surface of the Ga2O3absorption layer 106.

[0096] Specifically,

[0097] The substrate 101 is sapphire.

[0098] The thickness of the GaN buffer layer 102 is 1.8μm.

[0099] The material of the AlGaN insertion layer 103 is undoped Al 0.2 Ga 0.8 N, and the thickness of the AlGaN insertion layer 103 is 0.01 μm.

[0100] The GaN transmission layer 104 is undoped GaN, and the thickness of the GaN transmission layer 104 is 0.2 μm.

[0101] The material of the first insulating layer 105 is SiO2, and the thickness of the first insulating layer 105 is 0.05 μm. The thickness of the first insulating layer 105 is equal to the depth of the groove.

[0102] The material of the Ga2O3 absorption layer 106 is undoped Ga2O3, and the thickness of the Ga2O3 absorption layer 106 is 0.2 μm.

[0103] The material of the metal layer 107 is a stack of a metal Ni layer and a metal Au layer, and the thickness of the metal layer 107 is 110 nm. The pattern of the metal layer 107 is a rectangle.

[0104] The materials of the cathode electrode 108 and the anode electrode 109 are both Au.

[0105] Embodiment 2

[0106] As shown in FIG. 2, a solar blind ultraviolet detector is prepared according to the following steps: Figure 3

[0107] Step S6. An anode electrode 109 is disposed on the upper surface of the exposed part of the GaN transmission layer 104;

[0108] A second insulating layer 110 is epitaxially grown on the upper surface of the exposed part of the GaN transmission layer 104 and the upper surface of the Ga2O3 absorption layer 106;

[0109] A metal layer 107 is made on the upper surface of the second insulating layer 110;

[0110] A cathode electrode 108 is made on the upper surface of the Ga2O3 absorption layer 106, so that the cathode electrode 108 directly contacts the upper surface of the Ga2O3 absorption layer 106.

[0111] In the Ga2O3 absorption layer 106, the upper surface of the middle part and the right side surface are covered with the second insulating layer 110, the second insulating layer 110 is patterned with the metal layer 107, and the cathode electrode 108 is on the left side of the upper surface of the Ga2O3 absorption layer 106.

[0112] Specifically,

[0113] ​In step S6, a SiO2insulating layer is deposited on the upper surface of the exposed part of the GaN transmission layer 104 and the Ga2O3absorbing layer 106 in the ALD reaction furnace, and a second insulating layer 110 is formed on the Ga2O3absorbing layer 106 by a wet etching technique, wherein a part of the second insulating layer 110 covers the upper surface of the Ga2O3absorbing layer 106, and another part of the second insulating layer 110 completely covers the sidewall of the Ga2O3absorbing layer 106.

[0114] An anode electrode 109 is formed on the exposed part of the surface of the GaN transmission layer 104, and a cathode electrode 108 is formed on the Ga2O3absorbing layer 106 not covered by the second insulating layer 110 by using a photolithography technique and an electron beam evaporation process; and a patterned metal layer 107 is formed on the upper surface of the second insulating layer.

[0115] The pattern of the second insulating layer 110 is rectangular.

[0116] The material of the second insulating layer is SiO2, the projected area of the second insulating layer 110 is 20% to 80% of the upper surface area of the Ga2O3absorbing layer 106, and the thickness of the second insulating layer 110 is 0.05 μm.

[0117] The thickness of the GaN buffer layer 102 is 1.8 μm.

[0118] The thickness of the GaN transmission layer 104 is 6 μm.

[0119] Example 3

[0120] A solar blind ultraviolet detector, which is different from the example 1 in that the material of the cathode electrode is Ti.

[0121] Example 4

[0122] A solar blind ultraviolet detector, which is different from the example 1 in that,

[0123] The projected area of the Ga2O3absorbing layer 106 is 20% of the upper surface area of the GaN transmission layer 104.

[0124] The projected area of the groove in the GaN transmission layer 104 is 5% of the surface area of the GaN transmission layer 104.

[0125] The depth of the groove is 0.001 μm, and the thickness of the first insulating layer 105 is 0.001 μm.

[0126] The projected area of the metal layer 107 is 20% of the upper surface area of the Ga2O3absorbing layer 106.

[0127] The projected area of the second insulating layer 110 is 20% of the upper surface area of the Ga2O3absorbing layer 106, and the thickness of the second insulating layer 110 is 0.001 μm.

[0128] The thickness of the GaN buffer layer 102 is 1 μm, the thickness of the AlGaN insertion layer 103 is 0.005 μm, the thickness of the GaN transport layer 104 is 0.1 μm, the thickness of the Ga2O3 absorption layer 106 is 0.001 μm, and the thickness of the metal layer 107 is 1 nm.

[0129] Example 5

[0130] A solar blind ultraviolet detector, which is different from Example 1 in that,

[0131] The projected area of the Ga2O3 absorption layer 106 is 80% of the upper surface area of the GaN transport layer 104.

[0132] The projected area of the groove in the GaN transport layer 104 is 30% of the surface area of the GaN transport layer 104.

[0133] The depth of the groove is 1 μm, and the thickness of the first insulating layer 105 is 0.5 μm.

[0134] The projected area of the metal layer 107 is 80% of the upper surface area of the Ga2O3 absorption layer 106.

[0135] The projected area of the second insulating layer 110 is 80% of the upper surface area of the Ga2O3 absorption layer 106, and the thickness of the second insulating layer 110 is 0.5 μm.

[0136] The thickness of the GaN buffer layer 102 is 3 μm, the thickness of the AlGaN insertion layer 103 is 0.5 μm, the thickness of the GaN transport layer 104 is 5 μm, the thickness of the Ga2O3 absorption layer 106 is 0.5 μm, and the thickness of the metal layer 107 is 20 nm.

[0137] Comparative Example 1

[0138] As shown in Figure 4 A solar blind ultraviolet detector has the following structure:

[0139] From bottom to top, there are a substrate 101, a GaN buffer layer 102, an AlGaN insertion layer 103, and a GaN transport layer 104. A groove is formed in the middle of the transport layer 104, and a first insulating layer 105 is deposited in the groove. A Ga2O3 absorption layer 106 covers the middle of the GaN transport layer 104 and the first insulating layer 105, and a patterned metal layer 107 is on the Ga2O3 absorption layer 106. A cathode electrode 108 and an anode electrode 109 are respectively on the surface of the GaN transport layer 104.

[0140] The materials and structure of each layer are the same as those of Example 1, which will not be repeated here.

[0141] Results

[0142] The related performance of the above-mentioned examples and comparative examples of the solar blind ultraviolet detector was detected.

[0143] (1) The photo-generated hole concentration in the gallium oxide absorption layer: the test method was TCAD simulation software. The unit was cm -3 .

[0144] The specific detection results of example 1 and comparative example 1 are shown in the following table 1 and Figure 5 .

[0145] Table 1

[0146]

[0147] (2) The photocurrent: in the range of 1-6V, the test method was TCAD simulation. The unit was A / cm 2 .

[0148] The specific detection results of example 1 and comparative example 1 are shown in the following table 2 and Figure 6 .

[0149] Table 2

[0150] Voltage (V) 1 2 3 4 5 6 Example 1 2.30*10 -3 ]]> 2.41*10 -3 ]]> 2.43*10 -3 ]]> 2.45*10 -3 ]]> 2.46*10 -3 ]]> 2.48*10 -3 ]]> Comparative Example 1 2.25*10 -3 ]]> 2.34*10 -3 ]]> 2.36*10 -3 ]]> 2.38*10 -3 ]]> 2.40*10 -3 ]]> 2.44*10 -3 ]]>

[0151] From the above results, compared with comparative example 1, the photocurrent of the solar blind ultraviolet detector of the present application is significantly improved, and the photo-generated hole concentration in the Ga2O3 absorption layer of the solar blind ultraviolet detector of the present application is lower, which shows that in the solar blind ultraviolet detector of the present application, the cathode electrode in direct contact with the Ga2O3 absorption layer can effectively collect the photo-generated holes, so that the photo-generated electrons are more easily transported downward.

[0152] The photocurrent and dark current of the solar blind ultraviolet detector of the present application are related to the materials and sizes of the GaN buffer layer, the AlGaN insertion layer, the GaN transport layer, the first insulating layer, the Ga2O3 absorption layer, the patterned metal layer and the second insulating layer (if any).

[0153] Obviously, the above-mentioned examples 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, on the basis of the above description, other different forms of changes or variations can also be made. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A method for manufacturing a solar blind ultraviolet detector, characterized by, The method comprises the following steps: S1. sequentially epitaxially growing a GaN buffer layer (102), an AlGaN insertion layer (103) and a GaN transport layer (104) on the surface of a substrate (101); S2. etching the upper surface of the GaN transport layer (104) to obtain a groove; S3. depositing a first insulating layer (105) in the groove; S4. epitaxially growing a Ga2O3 absorbing layer (106) on the GaN transport layer (104) and the first insulating layer (105), so that the Ga2O3 absorbing layer (106) covers the first insulating layer (105); S5. etching part of the Ga2O3 absorbing layer (106) to expose part of the upper surface of the GaN transport layer (104); S6. disposing an anode electrode (109) on the exposed part of the upper surface of the GaN transport layer (104); and making a metal layer (107) and a cathode electrode (108) on the upper surface of the Ga2O3 absorbing layer (106), so that the cathode electrode (108) directly contacts the upper surface of the Ga2O3 absorbing layer (106).

2. The method for preparing a solar-blind ultraviolet detector according to claim 1, wherein: The step S6 comprises the following steps: disposing an anode electrode (109) on the exposed part of the upper surface of the GaN transport layer (104); epitaxially growing a second insulating layer (110) on the exposed part of the upper surface of the GaN transport layer (104) and the upper surface of the Ga2O3 absorbing layer (106); making a metal layer (107) on the upper surface of the second insulating layer (110); making a cathode electrode (108) on the upper surface of the Ga2O3 absorbing layer (106), so that the cathode electrode (108) directly contacts the upper surface of the Ga2O3 absorbing layer (106).

3. The method of claim 1, wherein the method further comprises: depositing a first layer of a material on the substrate; and depositing a second layer of a material on the first layer of material. The projected area of the Ga2O3 absorbing layer (106) is 20% to 80% of the area of the upper surface of the GaN transport layer (104).

4. The method of claim 1, wherein the method further comprises: depositing a first layer of a material on the substrate; and depositing a second layer of a material on the first layer of material. The projected area of the groove in the GaN transport layer (104) is 5% to 30% of the area of the surface of the GaN transport layer (104).

5. The method of claim 1, wherein the method further comprises: depositing a passivation layer on the substrate; and depositing a metal layer on the passivation layer. The depth of the groove is 0.001 μm to 1 μm, the thickness of the first insulating layer (105) is 0.001 μm to 0.5 μm, and the thickness of the first insulating layer (105) is less than or equal to the depth of the groove.

6. The method for preparing a solar-blind ultraviolet detector according to claim 1, wherein: The projected area of the metal layer (107) is 20% to 80% of the area of the upper surface of the Ga2O3 absorbing layer (106).

7. The method of claim 2, wherein the method further comprises: depositing a layer of a transparent material on the substrate; and depositing a layer of a reflective material on the layer of the transparent material. The projected area of the second insulating layer (110) is 20% to 80% of the area of the upper surface of the Ga2O3 absorbing layer (106), and the thickness of the second insulating layer (110) is 0.001 μm to 0.5 μm.

8. The method for preparing a solar-blind ultraviolet detector according to any one of claims 1 to 7, characterized in that: The thickness of the GaN buffer layer (102) is 1 μm to 3 μm, the thickness of the AlGaN insertion layer (103) is 0.005 μm to 0.5 μm, the thickness of the GaN transport layer (104) is 0.1 μm to 5 μm, the thickness of the Ga2O3 absorbing layer (106) is 0.001 μm to 0.5 μm, and the thickness of the metal layer (107) is 1 nm to 20 nm.

9. The solar blind ultraviolet detector prepared by the method of any one of claims 1-8.

10. The solar blind ultraviolet detector of claim 9 for use in fire monitoring, missile early warning, astronomy, chemical analysis, biological analysis, space communication.

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