Gallium oxide circular truncated cone micron column-PANI PN type ultraviolet detector

Abstract

The invention discloses a PN type ultraviolet detector of a gallium oxide circular truncated cone micron column-PANI, and aims to provide an ultraviolet detection solution which is efficient, sensitive and stable in performance. The PN junction sequentially comprises a substrate layer, a gallium oxide layer, a gallium oxide circular truncated cone micron column array, a polyaniline (Polyaniline, PANI) layer and an electrode layer from bottom to top; wherein the N-type semiconductor is a gallium oxide layer and a gallium oxide circular truncated cone micron column array, the P-type semiconductor is a PANI layer, the gallium oxide layer is made of alpha-phase, kappa-phase, gamma-phase or beta-phase gallium oxide, and the gallium oxide circular truncated cone micron column is made of alpha-phase, kappa-phase, gamma-phase or beta-phase gallium oxide. Compared with a common PN type detector, the gallium oxide circular truncated cone micron column structure is introduced, the surface area of the detector is greatly increased, absorption of ultraviolet light is increased, the absorption efficiency and response speed of the detector are improved, compared with gallium oxide of a nano structure, the gallium oxide circular truncated cone micron column array prepared through the method is accurate and controllable in morphology, and the detection sensitivity is improved. The manufacturing process is simple.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a PN type ultraviolet detector of gallium oxide truncated cone micrometer column-PANI and a preparation method thereof. Background Art

[0002] In today's era of continuous technological development, ultraviolet detection technology has a vital demand in many fields. For example, in the field of environmental monitoring, accurate detection of ultraviolet intensity can help evaluate the thickness and changes of the atmospheric ozone layer, as well as monitor the impact of harmful ultraviolet radiation on organisms and ecosystems. In industrial production, ultraviolet detection can be used for quality control and process monitoring, such as the detection of the degree of curing of coatings and glues. In the military and security fields, ultraviolet detectors can be used for missile tail flame detection, ultraviolet warning, etc., to improve the early warning capability and safety of military equipment. Gallium oxide, as a new type of wide bandgap semiconductor material, has many excellent properties, which makes it have great potential in the field of ultraviolet detection. The bandgap width of gallium oxide is 4.2~4.9eV, which corresponds to the absorption cutoff edge of the ultraviolet band, making it highly sensitive to ultraviolet light. At the same time, gallium oxide has high thermal stability, chemical stability and mechanical strength, and can work in harsh environments. Traditional PN-type ultraviolet detectors have limited response speed, need to improve sensitivity, and low light absorption efficiency.

[0003] Based on the above reasons, the development of a PN-type ultraviolet detector based on gallium oxide truncated cone micrometer pillars-PANI has important practical significance and application value. It can overcome the shortcomings of existing ultraviolet detectors and meet the needs of high-performance ultraviolet detection in different fields. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides a PN-type ultraviolet detector of gallium oxide truncated cone micron pillar-PANI. The introduction of gallium oxide truncated cone micron pillars increases the surface area of ​​the detector and improves the absorption of ultraviolet light. Compared with other PN-type gallium oxide ultraviolet detectors, the gallium oxide truncated cone micron pillar array prepared by the present invention has controllable morphology and better performance.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] The present invention discloses a gallium oxide truncated cone micron column-PANI PN type ultraviolet detector, aiming to provide an efficient, sensitive and stable ultraviolet detection solution. The PN type detector comprises a substrate layer, a gallium oxide layer, a gallium oxide truncated cone micron column, a polyaniline (PANI) layer and an electrode layer from bottom to top; the gallium oxide layer material is α-phase, κ-phase, γ-phase or β-phase gallium oxide, and the gallium oxide truncated cone micron column material is α-phase, κ-phase, γ-phase or β-phase gallium oxide.

[0007] The preparation method of the gallium oxide truncated cone micron column-PANI PN type ultraviolet detector comprises the following steps:

[0008] (1) First, a gallium oxide layer is prepared on a substrate using mist chemical vapor deposition (Mist-CVD), and high-quality gallium oxide is prepared by adjusting the precursor concentration and growth temperature during the Mist-CVD process;

[0009] (2) using PECVD or ALD technology to grow a silicon dioxide layer on the gallium oxide layer;

[0010] (3) Based on integrated circuit process technology, a certain thickness of photoresist is applied on the silicon dioxide layer, a mask is covered on the photoresist, and exposure and development steps are performed;

[0011] (4) Use EUV lithography technology to etch the unprotected area and create patterns;

[0012] (5) Using etching techniques such as RIE and ICP, the pattern on the photoresist is transferred to the silicon dioxide layer, and the silicon dioxide layer is used as a pattern mask for the next preparation process;

[0013] (6) The photoresist is then washed away to obtain a silicon dioxide mask structure, and the substrate with the pattern is placed in a hydride vapor phase epitaxy (HVPE) chamber;

[0014] (7) preparing a gallium oxide material with a desired crystal orientation by adjusting the growth temperature, growth time, ratio of oxygen to hydrogen chloride and pressure during the HVPE secondary epitaxial growth process;

[0015] (8) After washing away the silicon dioxide with HF, a gallium oxide truncated cone micrometer column array with a desired crystal orientation is obtained;

[0016] (9) Spin-coating a photoresist on the surface of the micron pillar, and transferring the designed pattern to the photoresist by photolithography technology, so that the photoresist on the right half of the micron pillar is retained and the photoresist on the left half is removed, thereby exposing the left half of the micron pillar;

[0017] (10) immersing the treated micro-columns in a solution containing aniline monomers. Since the right half of the micro-columns is protected by photoresist, the aniline monomers are mainly adsorbed on the left half of the micro-columns.

[0018] (11) adding an oxidant, such as ammonium persulfate, to the solution to initiate a chemical oxidation polymerization reaction of aniline on the left half of the micron column to form PANI. After the reaction is completed, removing the photoresist with a suitable solvent to obtain a structure in which PANI grows on the left half of the micron column;

[0019] (12) Chemical vapor deposition was used to deposit clicks on the upper surface of PANI and on the top of gallium oxide truncated cone micro-pillars without PANI growth.

[0020] Furthermore, in the step (1), during the Mist-CVD process, the precursors are trimethylgallium and oxygen, the concentration of which is 5 to 20 mmol / L, and the growth temperature is 400° C. to 900° C.;

[0021] Furthermore, in step (1), the thickness of the gallium oxide layer is 50 nm to 1000 nm;

[0022] Furthermore, in step (2), the thickness of the silicon dioxide layer is 50 nm to 500 nm;

[0023] Furthermore, in the step (7), the growth temperature during the HVPE secondary epitaxial growth is 450°C to 1000°C, the growth time is 0.1 to 3 hours, the ratio of oxygen to hydrogen chloride is 1:1 to 10:1; and the pressure is 1 to 10 kPa;

[0024] Furthermore, in the steps (2) to (8), the upper surface width of the truncated cone micro-pillar is 1 to 5 μm, the lower surface width is 1 to 10 μm, and the height is 50 nm to 10000 nm;

[0025] Furthermore, in the steps (9) to (11), the thickness of the PANI layer is 50 nm to 5000 nm;

[0026] Furthermore, in step (12), the electrode layer is a metal electrode Al / Ti; the thickness of the electrode is 30 to 50 nm;

[0027] Furthermore, the substrate is an insulating or conductive substrate, such as a gallium oxide single crystal, sapphire, silicon, an ITO conductive glass substrate, etc.

[0028] Beneficial Effects

[0029] (1) The structural design of the present invention, including a substrate, a gallium oxide layer, a gallium oxide truncated cone micro-column layer, a PANI layer and an interdigitated electrode layer, can achieve efficient detection of ultraviolet light. Among them, the combination of the gallium oxide layer and the gallium oxide truncated cone micro-column layer greatly improves the absorption of ultraviolet light, so that the detector has extremely high sensitivity in the ultraviolet band and can accurately detect weak ultraviolet light signals.

[0030] (2) The gallium oxide material used in the present invention has good chemical stability and thermal stability and is easy to prepare into high-quality thin films and micron column structures.

[0031] (3) Compared with nanostructured gallium oxide, the gallium oxide frustum micrometer column array prepared by the present invention has a precise and controllable morphology and a simple manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the preparation steps of the PN type ultraviolet detector of gallium oxide truncated cone micron column-PANI of the present invention;

[0033] Figure 2 A front view of the PN type ultraviolet detector of the gallium oxide truncated cone micron column-PANI of the present invention

[0034] Figure 3 This is a scanning electron microscope image of the gallium oxide frustum micrometer column of the present invention. Specific implementation methods

[0035] The following will further describe the embodiments of the present invention in detail with reference to the accompanying drawings. Obviously, the described embodiment is an embodiment of a PN junction ultraviolet detector of α-phase gallium oxide micrometer column-PANI, which is only a part of the present invention, not all embodiments, and micrometer column arrays of gallium oxide in other crystal directions all belong to the protection scope of the present invention. The described embodiments are only for illustration and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0036] like Figures 1-2 As shown, this example is a preparation step of a PN type detector of gallium oxide truncated cone micro-pillar-PANI, wherein the PN junction structure of the gallium oxide truncated cone micro-pillar-PANI includes, from bottom to top, a substrate layer 101, a gallium oxide layer 201, a gallium oxide truncated cone micro-pillar array 202, a polyaniline (PANI) layer 301 and an electrode layer 401; wherein the N region includes the gallium oxide layer 201 and the gallium oxide truncated cone micro-pillar array 202, and the P region is the PANI layer 301.

[0037] like Figure 1 The figure shows the PN junction preparation process of gallium oxide frustum micrometer pillar-PANI, which specifically includes the following steps:

[0038] (1) firstly prepare a gallium oxide layer 102 on a sapphire substrate 101 by mist chemical vapor deposition (Mist-CVD), adjust the precursor concentration to 5-20 mmol / L and the growth temperature to 550° C. during the Mist-CVD process; the gallium oxide layer 102 has a thickness of 50 nm to 1000 nm;

[0039] (2) Using PECVD or ALD technology, a silicon dioxide layer 103 is grown on the gallium oxide layer 102; the thickness of the silicon dioxide layer 103 is 50 nm to 500 nm;

[0040] (3) Based on integrated circuit process technology, a certain thickness of photoresist is applied on the silicon dioxide layer 103, a mask is covered on the photoresist, and exposure and development steps are performed;

[0041] (4) using EUV lithography technology to etch the unprotected area to form pattern 104;

[0042] (5) using etching techniques such as RIE and ICP to transfer the pattern 104 on the photoresist to the silicon dioxide layer, and using the silicon dioxide layer 103 as a pattern mask for the next preparation process;

[0043] (6) Afterwards, the photoresist is washed away to obtain a silicon dioxide mask structure, and the substrate with the pattern is placed in a HVPE chamber;

[0044] (7) adjusting the growth temperature during the HVPE secondary epitaxial growth process to 550° C., the growth time to 0.5 h, the ratio of oxygen to hydrogen chloride to 5:1, and the pressure to 3 kPa to prepare the gallium oxide material 105 with the desired crystal orientation;

[0045] (8) After washing away the silicon dioxide with HF, a gallium oxide truncated cone micro-pillar array 106 with a desired crystal orientation is obtained, such as Figure 3 The figure shows a scanning electron microscope image of a gallium oxide micro-rod. The micro-rod has an upper surface width of 2.4 μm, a lower surface width of 3.5 μm, and a height of 2000 nm.

[0046] (9) Spin-coating photoresist on the surface of the gallium oxide truncated cone micro-pillar 106, and transferring the designed pattern to the photoresist by photolithography technology, so that the photoresist on the right half of the micro-pillar 106 is retained and the photoresist on the left half is removed, thereby exposing the left half of the micro-pillar 106;

[0047] (10) The processed micro-columns 106 are immersed in a solution containing aniline monomers. Since the right half of the micro-columns 106 are protected by photoresist, the aniline monomers are mainly adsorbed on the left half of the micro-columns 106 .

[0048] (11) adding ammonium persulfate as an oxidant to the solution to initiate a chemical oxidation polymerization reaction of aniline on the left half of the micron column 106 to form PANI. After the reaction is completed, using a tetramethylammonium hydroxide solution with a concentration of 1% to 2% to remove the photoresist at low temperature, obtaining a PANI layer 107 grown on the left half of the micron column 106; the thickness of the PANI layer is 1500 nm;

[0049] (12) Using chemical vapor deposition, a metal electrode 108 is deposited on the upper surface of PANI 107 and on the top of the gallium oxide truncated cone micro-pillar 106 where no PANI is grown; the metal electrode 108 used is Al / Ti; and the thickness of the electrode is 30 to 50 nm.

Claims

1. A PN-type ultraviolet detector of gallium oxide truncated cone micro-pillar-PANI, wherein the structure of the PN-type detector comprises, from bottom to top, a substrate layer, a gallium oxide truncated cone micro-pillar array, a polyaniline (PANI) layer and an electrode layer; characterized in that: The steps include: (1) First, a gallium oxide layer is prepared on a substrate using mist chemical vapor deposition (Mist-CVD), and high-quality gallium oxide is prepared by adjusting the precursor concentration and growth temperature during the Mist-CVD process; (2) using PECVD or ALD technology to grow a silicon dioxide layer on the gallium oxide layer; (3) Based on integrated circuit process technology, a certain thickness of photoresist is applied on the silicon dioxide layer, a mask is covered on the photoresist, and exposure and development steps are performed; (4) Use EUV lithography technology to etch the unprotected area and create patterns; (5) Using etching techniques such as RIE and ICP, the pattern on the photoresist is transferred to the silicon dioxide layer, and the silicon dioxide layer is used as a pattern mask for the next preparation process; (6) Afterwards, the photoresist is washed away to obtain a silicon dioxide mask structure, and the substrate with the pattern is placed in a HVPE chamber; (7) preparing a gallium oxide material with a desired crystal orientation by adjusting the growth temperature, growth time, ratio of oxygen to hydrogen chloride and pressure during the HVPE secondary epitaxial growth process; (8) After washing away the silicon dioxide with hydrofluoric acid (HF), a gallium oxide truncated cone micrometer column array with a desired crystal orientation is obtained; (9) Spin-coating photoresist on the surface of the micron pillar, and transferring the designed pattern to the photoresist by photolithography technology, so that the photoresist on the right half of the micron pillar is retained and the photoresist on the left half is removed, thereby exposing the left half of the micron pillar; (10) The treated micro-columns are immersed in a solution containing aniline monomers. Since the right half of the micro-columns is protected by photoresist, the aniline monomers are mainly adsorbed on the left half of the micro-columns. (11) An oxidant is added to the solution to initiate a chemical oxidative polymerization reaction of aniline on the left half of the micron column to form PANI. After the reaction is completed, the photoresist is removed by a tetramethylammonium hydroxide solution to obtain a structure in which PANI is grown on the left half of the micron column. (12) Electrodes were deposited on the upper surface of PANI and on the top of the gallium oxide truncated cone micro-pillars without PANI growth by chemical vapor deposition.

2. The PN type ultraviolet detector of gallium oxide truncated cone micro-rod-PANI according to claim 1, characterized in that: A layer of gallium oxide truncated cone micrometer column array is grown on the gallium oxide layer, which together constitute the N region of the PN type detector.

3. The PN type ultraviolet detector of gallium oxide truncated cone micro-rod-PANI according to claim 1, characterized in that: The P-type semiconductor used is PANI.

4. The PN type ultraviolet detector of gallium oxide truncated cone micro-rod-PANI according to claim 1, characterized in that: The thickness of the prepared gallium oxide layer is 50nm-1000nm; the thickness of the PANI layer is 50nm-5000nm.

5. The PN type ultraviolet detector of gallium oxide truncated cone micro-rod-PANI according to claim 1, characterized in that: The prepared gallium oxide truncated cone micron column has an upper surface width of 1 to 5 μm, a lower surface width of 1 to 10 μm, and a height of 50 nm to 10000 nm.

6. The PN type ultraviolet detector of gallium oxide truncated cone micro-rod-PANI according to claim 1, characterized in that: The gallium oxide layer material is α-phase, κ-phase, γ-phase or β-phase gallium oxide, and the gallium oxide frustum micrometer column material is α-phase, κ-phase, γ-phase or β-phase gallium oxide.

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