Transistor type detector based on aluminum nano array and gallium oxide and preparation method thereof

Abstract

The invention provides a transistor type detector based on an aluminum nano array and gallium oxide. The transistor type detector comprises a substrate; the gate layer grows on the substrate and covers the substrate; the gate dielectric layer grows on the gate layer and exposes an upper surface area on one side of the gate layer; the light absorption layer is arranged on the middle section of the surface of the gate dielectric layer and is a gallium oxide table top; the aluminum nano array layer is arranged in the middle area of the light absorption layer, and a plasmon effect can be generated on the surface of the aluminum nano array layer; the source electrode covers the gate dielectric layer and the upper surface area of one side of the light absorption layer; the drain electrode covers the gate dielectric layer and the upper surface area of the other side of the light absorption layer; and the packaging layer covers the upper surfaces of the gate layer, the light absorption layer and the aluminum nano array layer. According to the detector, solar-blind ultraviolet band light can be effectively detected based on the material characteristics of gallium oxide, and surface plasmons are generated based on the aluminum nano array layer, so that the performance of the detector is improved. The invention further provides a preparation method of the transistor type detector based on the aluminum nano array and gallium oxide.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor devices, and more specifically, to a transistor-type detector based on an aluminum nanoarray and gallium oxide and a preparation method thereof. Background Art

[0002] Solar-blind ultraviolet photodetectors are detectors that respond to ultraviolet light with a wavelength between 200-280nm. Due to the presence of the atmosphere, ultraviolet light in this band is almost completely absorbed and has difficulty reaching the earth's surface. Therefore, detectors in this band have advantages such as low background noise and low false alarm rate, and have broad application prospects in many fields, such as flame detection, biomedicine, environmental monitoring, corona detection, etc.

[0003] As a wide-bandgap semiconductor material, gallium oxide exhibits weak absorption of visible and near-infrared light, resulting in excellent wavelength selectivity when fabricated into solar-blind photodetectors. Furthermore, gallium oxide has a stable crystal structure that facilitates electron conduction and exhibits high thermal stability and radiation resistance in atmospheric environments.

[0004] Aluminum plasmons refer to aluminum nanostructures that, under the irradiation of incident light, can significantly increase the surface light energy density and enhance the local electromagnetic field due to the localized surface plasmon resonance (LSPR) effect. Therefore, the localized surface plasmon resonance effect is widely used in photodetectors to enhance the device's response to light, thereby improving the performance of the detector.

[0005] Thanks to the high responsiveness of gallium oxide materials to ultraviolet light and the plasmon enhancement effect of aluminum nanoarrays, the detector can effectively improve the responsiveness of photodetectors, reduce response time, and achieve high-precision optical signal detection. Summary of the Invention

[0006] In view of this, the present disclosure provides a transistor-type detector based on aluminum nanoarray and gallium oxide and a preparation method thereof.

[0007] One aspect of the present disclosure provides a transistor-type detector based on an aluminum nanoarray and gallium oxide, comprising: a substrate; a gate layer grown on the substrate and covering the substrate; a gate dielectric layer grown on the gate layer and exposing an upper surface area on one side of the gate layer; a light absorption layer, disposed in the middle section of the surface of the gate dielectric layer and being a gallium oxide table; an aluminum nanoarray layer, disposed in the middle area of ​​the light absorption layer, the surface of which can generate a plasmon effect; a source electrode, covering the upper surface area on one side of the gate dielectric layer and the light absorption layer, close to the side of the gate layer where the upper surface is exposed; a drain electrode, covering the upper surface area on the other side of the gate dielectric layer and the light absorption layer; an encapsulation layer, covering the upper surfaces of the gate layer, the light absorption layer and the aluminum nanoarray layer, and having openings above the gate layer, the source electrode and the drain electrode.

[0008] According to an embodiment of the present disclosure, the contact surface between the aluminum nano-array layer and the gallium oxide mesa is passivated to form aluminum oxide.

[0009] According to an embodiment of the present disclosure, the substrate is a thermally oxidized silicon dioxide / single crystal silicon substrate.

[0010] According to an embodiment of the present disclosure, the gate layer is made of metal or polysilicon.

[0011] According to an embodiment of the present disclosure, the gate dielectric layer is lattice-matched with the gate layer and the gallium oxide mesa.

[0012] According to an embodiment of the present disclosure, the source and the drain are made of a metal that matches the work function of gallium oxide.

[0013] According to an embodiment of the present disclosure, the array form of the aluminum nanoarray layer is a dot array or a line array.

[0014] Another aspect of the present disclosure provides a method for preparing a transistor-type detector based on an aluminum nanoarray and gallium oxide, which is applied to the transistor-type detector based on the aluminum nanoarray / gallium oxide as described in any of the above aspects, comprising: epitaxially growing a gate layer on a substrate; growing a gate dielectric layer on the gate layer, the growth method being plasma-enhanced chemical vapor transport or magnetron sputtering, the area of ​​the gate dielectric layer being smaller than the gate layer; depositing and growing gallium oxide on the gate dielectric layer, and preparing gallium oxide mesas by photolithography and etching to form a light absorption layer, and after etching, repairing the surface of the gallium oxide mesas and the surface of the gate dielectric layer using chemical reagents, and isolating the mesas with silicon oxide; preparing an aluminum film on the absorption layer using electron beam evaporation technology, then preparing an array pattern by electron beam exposure, and etching to prepare an aluminum nanoarray layer; removing part of the silicon oxide isolating the gallium oxide mesas by photolithography and etching, photoetching an electrode pattern, depositing metal by electron beam evaporation, and obtaining a source and a drain after peeling; preparing silicon oxide with good density by plasma-enhanced chemical vapor transport, and opening holes above the source and the drain to form an encapsulation layer.

[0015] At least one of the above technical solutions adopted in the embodiments of the present disclosure can achieve the following beneficial effects:

[0016] The present disclosure provides a transistor-type detector based on an aluminum nanoparticle array and gallium oxide. This photodetector adopts a transistor-type structure. The light response intensity of the photodetector can be controlled by adjusting the gate voltage. The localized surface plasmon resonance effect of the aluminum nanoparticle array can enhance the detection performance of the gallium oxide photodetector, thereby expanding the application range of gallium oxide solar-blind ultraviolet photodetectors.

[0017] Transistor-type detectors based on aluminum nanoarrays and gallium oxide are prepared through semiconductor micro-nano processing technology. The entire process is simple, the device size is controllable and the stability is good; the performance of the device is stable after packaging, which helps to achieve mass production of large-scale device construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1A The schematic diagram of the structure of a transistor-type detector based on aluminum nanoarray / gallium oxide provided by an embodiment of the present disclosure is shown;

[0020] Figure 1B A schematic top view of a transistor-type detector based on aluminum nanoarray / gallium oxide provided by an embodiment of the present disclosure is shown;

[0021] Figure 2The flowchart of the method for preparing a transistor-type detector based on aluminum nanoarray / gallium oxide provided by an embodiment of the present disclosure is schematically shown.

[0022] Description of reference numerals:

[0023] 11 - substrate; 12 - gate layer; 13 - gate dielectric layer; 14 - source electrode; 15 - drain electrode; 16 - aluminum nanoarray; 17 - gallium oxide light absorption layer. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0025] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0026] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0027] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0028] like Figure 1A As shown, an embodiment of the present disclosure provides a transistor-type detector based on an aluminum nanoarray and gallium oxide, including: a substrate 11, a gate layer 12, a gate dielectric layer 13, a source 14, a drain 15, an aluminum nanoarray 16, and a gallium oxide light absorption layer 17.

[0029] Among them, the substrate 11 is a silicon dioxide / single crystal silicon substrate after thermal oxidation. The silicon dioxide of the substrate must reach a certain thickness to prevent the occurrence of leakage. The gate layer 12 grows on the substrate 11, covering the substrate 11, and can be made of polysilicon or metal materials. The gate dielectric layer 13 grows on the gate layer 12, exposing the upper surface area on one side of the gate layer 12. The area of ​​the gate dielectric layer 13 needs to be smaller than the area of ​​the gate layer, exposing part of the gate layer for setting the gate voltage. It can be adjusted according to the gate layer 12. The corresponding gate dielectric layer 13 is selected from the material, and the gate dielectric layer 13 is lattice-matched with the gate layer 12 and the gallium oxide table; the light absorption layer 17 is arranged in the middle section of the surface of the gate dielectric layer 13, which is a gallium oxide table; the aluminum nanoarray layer 16 is arranged in the middle area of ​​the light absorption layer 17, and its surface can generate a plasmon effect; the source 14 covers the upper surface area of ​​the gate dielectric layer 13 and the light absorption layer 17 on one side, close to the side where the upper surface of the gate layer 12 is exposed; the drain 15 covers the upper surface area of ​​the gate dielectric layer 13 and the light absorption layer 17 on the other side; the material of the source 14 and the drain 15 is a metal that matches the work function of gallium oxide, and gallium oxide and the source 14 and the drain 15 need to form an ohmic contact with a small contact resistance; the encapsulation layer covers the upper surface of the gate layer 12, the light absorption layer and the aluminum nanoarray layer 16.

[0030] The array form can be selected as dot matrix or linear matrix. The dot matrix can change the shape of the graphic, and the linear matrix can change the period and duty cycle. Comparison is made through computational simulation and experimental verification.

[0031] like Figure 1B As shown, in the embodiment of the present disclosure, the schematic diagram shows a square lattice type aluminum nanoarray 16. When the incident light irradiates the surface of the photodetector, the aluminum nanoarray 16 will generate local plasma resonance, generate a local strong electric field, and enhance the absorption of ultraviolet light by the gallium oxide light absorption layer 17, thereby enhancing the responsiveness of the photodetector and reducing the response time of the photodetector.

[0032] When preparing aluminum nanoarrays, aluminum easily forms aluminum oxide on its surface in the atmospheric environment. A passivation layer is formed where aluminum oxide contacts gallium oxide, which can effectively reduce the dark current of the photodetector.

[0033] In this embodiment, the metals used for the source electrode 14 and the drain electrode 15 must match the work function of gallium oxide. After rapid thermal annealing, the metal electrodes must form an ohmic contact with the gallium oxide material. By adjusting the experimental conditions, the contact resistance can be reduced, thereby optimizing the performance of the photodetector. Furthermore, the voltage of the gate layer 12 can be modulated to control the photoresponse and, therefore, the photocurrent. This photocurrent modulation property can expand the application range of solar-blind ultraviolet photodetectors.

[0034] like Figure 2As shown, another embodiment of the present disclosure provides a method for preparing a transistor-type detector based on aluminum nanoarrays and gallium oxide, including S110 to S115.

[0035] S110, epitaxially growing a gate layer 12 on the substrate. Optionally, a corresponding epitaxial method is selected according to the gate material, for example, electron beam evaporation is used for metal materials, and chemical vapor deposition or physical vapor deposition is used for polysilicon.

[0036] S111, growing a gate dielectric layer 13 on the gate layer 12 using plasma enhanced chemical vapor transport or magnetron sputtering. The gate dielectric layer 13 has a smaller area than the gate layer 12. An appropriate gate dielectric layer thickness is required to achieve good gate control characteristics and prevent leakage.

[0037] S112, gallium oxide is deposited and grown on the gate dielectric layer 13, and gallium oxide mesas are prepared by photolithography and etching to form a light absorption layer 17. After etching, the surfaces of the gallium oxide mesas and the gate dielectric layer 13 are repaired using chemical reagents, and the mesas are isolated with silicon oxide.

[0038] S113, using electron beam evaporation technology to form an aluminum thin film on the absorption layer 17, then using electron beam exposure to form an array pattern, and etching to form an aluminum nanoarray layer 16. The array can be a dot matrix or a linear array, and the specific size and period can be determined using the finite difference time domain simulation method.

[0039] S114, using photolithography and etching to remove part of the silicon oxide that isolates the gallium oxide mesa, photolithography to form an electrode pattern, using electron beam evaporation to deposit metal, and after peeling off, the source 14 and the drain 15 are obtained.

[0040] S115, using plasma enhanced chemical vapor transport to prepare silicon oxide with good density, and opening holes above the source and drain to form an encapsulation layer.

[0041] The preparation method of the day-blind ultraviolet photodetector provided in the embodiment of the present disclosure has a simple entire process flow, can prepare smaller devices with higher stability, and the performance of the device is stable after packaging, which helps to realize mass production of large-scale device construction.

[0042] According to an embodiment of the present disclosure, a transistor-type detector based on an aluminum nanoarray / gallium oxide is provided. An ultraviolet light surface current test system can be used to test the surface current of the photodetector, and then the principle of the photodetector can be theoretically analyzed. The aluminum nanoarray can then be optimized based on the surface current test results.

[0043] Specifically, the steps of performing an ultraviolet light surface current test on the transistor-type detector based on aluminum nanoarray / gallium oxide provided by the embodiment of the present disclosure include S210-S212.

[0044] S210, debug the laser spot. By adjusting the fiber coupler, a circular laser spot is emitted from the output end of the optical fiber, and the output laser power reaches the maximum. Then, a collimator is used to collimate the laser spot. The laser then passes through a mechanical chopper and an ultraviolet reflective lens and is incident on the detector surface.

[0045] S211, use the sample holder to fix the aluminum nanoarray / gallium oxide transistor-type detector on the sample stage, use the stepper motor operating system to initialize the position of the detector, then input the light spot coordinates, use the stepper motor to control the photodetector, and let the light spot be incident on the upper left corner of the photodetector.

[0046] S212, set the stepper motor program to control the scanning step length and scanning range. The signal passes through the preamplifier, phase-locked amplifier, and information acquisition chip. The current information of the sample is filtered and amplified by the preamplifier and converted into voltage information, and then output to the phase-locked amplifier. The synchronization signal of the mechanical chopper is input to the phase-locked amplifier, the small voltage signal is integrated, and finally a larger voltage signal is output to the information acquisition chip. The signal is observed by the computer. After the stepper motor program ends, the current information of each acquisition point is combined into a surface current image.

[0047] The detection principle of the transistor-type detector based on aluminum nanoarray / gallium oxide is verified based on the surface current test results. First, the enhancement effect of the localized plasma resonance effect of the aluminum nanoarray is verified. In addition, the differences in the enhancement effects of different types of arrays can also be verified.

[0048] The above describes the embodiments of the present disclosure. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A transistor-type detector based on aluminum nanoarray and gallium oxide, characterized in that: include: substrate (11); a gate layer (12), grown on the substrate (11) and covering the substrate (11); a gate dielectric layer (13) grown on the gate layer (12) and exposing a portion of the upper surface area on one side of the gate layer (12); A light absorption layer (17) is provided in the middle section of the surface of the gate dielectric layer (13) and is a gallium oxide mesa; an aluminum nanoarray layer (16), disposed in the middle region of the light absorption layer (17), the surface of which can generate a plasmon effect; A source electrode (14), covering the upper surface area of ​​one side of the gate dielectric layer (13) and the light absorption layer (17), and close to the side of the gate layer (12) where the upper surface is exposed; a drain electrode (15) covering the upper surface area of ​​the gate dielectric layer (13) and the other side of the light absorption layer (17); The encapsulation layer covers the upper surfaces of the gate layer (12), the light absorption layer (17), and the aluminum nanoarray layer (16), and has holes opened above the gate layer (12), the source electrode (14), and the drain electrode (15).

2. The transistor-type detector based on aluminum nanoarray / gallium oxide according to claim 1, characterized in that: The contact surface between the aluminum nanoarray layer (16) and the gallium oxide table is passivated to form aluminum oxide.

3. The transistor-type detector based on aluminum nanoarray / gallium oxide according to claim 1, characterized in that: The substrate (11) is a thermally oxidized silicon dioxide / single crystal silicon substrate.

4. The transistor-type detector based on aluminum nanoarray / gallium oxide according to claim 1, characterized in that: The material of the gate layer (12) is metal or polysilicon.

5. The transistor-type detector based on aluminum nanoarray / gallium oxide according to claim 1, characterized in that: The gate dielectric layer (13) is lattice-matched with the gate layer (12) and the gallium oxide mesa.

6. The transistor-type detector based on aluminum nanoarray / gallium oxide according to claim 1, characterized in that: The material of the source electrode (14) and the drain electrode (15) is a metal that matches the work function of gallium oxide.

7. The transistor-type detector based on aluminum nanoarray and gallium oxide according to claim 1, characterized in that: The array form of the aluminum nanoarray layer (16) is a dot array or a line array.

8. A method for preparing a transistor-type detector based on aluminum nanoparticle array / gallium oxide, applied to the transistor-type detector based on aluminum nanoparticle array / gallium oxide according to any one of claims 1 to 7, characterized in that: include: Epitaxially growing a gate layer (12) on a substrate; Growing a gate dielectric layer (13) on the gate layer (12) using a plasma-enhanced chemical vapor transport or magnetron sputtering method, wherein the gate dielectric layer (13) has an area smaller than that of the gate layer (12); Gallium oxide is deposited and grown on the gate dielectric layer (13), and a gallium oxide mesa is prepared by photolithography and etching to form a light absorption layer (17). After etching, the surface of the gallium oxide mesa and the surface of the gate dielectric layer (13) are repaired using a chemical reagent, and the mesas are isolated using silicon oxide; An aluminum film is prepared on the absorption layer (17) using electron beam evaporation technology, an array pattern is prepared using electron beam exposure, and an aluminum nano-array layer (16) is prepared by etching; Using photolithography and etching to remove part of the silicon oxide that isolates the gallium oxide mesa, photolithography to form an electrode pattern, using electron beam evaporation to deposit metal, and after stripping, obtaining a source electrode (14) and a drain electrode (15); Plasma-enhanced chemical vapor transport is used to prepare silicon oxide with good density, and holes are opened above the gate layer, source and drain to form an encapsulation layer.

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