A gallium oxide photodetector and a preparation method thereof

Abstract

This invention relates to the field of photodetectors, and more specifically, to a gallium oxide photodetector and its fabrication method. The invention involves preparing a gallium oxide thin film doped with a predetermined element on a substrate surface, and simultaneously subjecting a predetermined region on the surface of the gallium oxide thin film to laser irradiation and ion bombardment to obtain a space charge region for charge transport. The invention also discloses a gallium oxide photodetector. Through doping technology, this invention not only modulates the electrical properties of the gallium oxide thin film but also lowers its crystallization temperature. Furthermore, by simultaneously subjecting the gallium oxide thin film to laser irradiation and ion bombardment, the invention achieves localized fabrication of the space charge region, thereby realizing a high-sensitivity photodetector.

Description

Technical Field

[0001] This invention relates to the field of photodetectors, and more specifically, to a gallium oxide photodetector and its fabrication method. Background Technology

[0002] Gallium oxide, as a high-performance semiconductor material, has significant application value in fields such as solar-blind ultraviolet detection and X-ray detection. However, existing technologies face some insurmountable challenges in the fabrication of high-performance gallium oxide photodetectors.

[0003] Firstly, doping technology is a key means to achieve the desired electrical properties of gallium oxide. However, current doping methods, such as ion implantation and thermal diffusion, have significant shortcomings. While ion implantation can achieve precise control over the doping site, the process is complex and costly. Furthermore, ion implantation can damage the material, affecting device performance. Thermal diffusion, on the other hand, suffers from low doping efficiency and difficulty in controlling the diffusion depth, resulting in unsatisfactory doping effects. This not only affects the electrical properties of gallium oxide but also limits the sensitivity and dynamic range of photodetectors.

[0004] Secondly, high-temperature annealing is a commonly used method for controlling the crystal structure of gallium oxide. However, high-temperature annealing technology has many drawbacks. First, the high-temperature annealing process consumes a lot of energy and requires sophisticated equipment, increasing the manufacturing cost. Second, high-temperature annealing can also cause changes in the internal stress of the material, leading to instability in device performance. More importantly, high-temperature annealing makes it difficult to fabricate large-area devices, limiting the widespread application of gallium oxide photodetectors in practical applications.

[0005] In summary, existing technologies for controlling the electrical properties and crystal structure of gallium oxide (GaO) face numerous challenges, such as complex fabrication processes, insufficient doping effects and uniformity, high annealing temperatures, and difficulties in achieving large-area devices. These issues severely restrict the performance improvement of GaO photodetectors in terms of high sensitivity, high dynamic range, and fast response. Therefore, developing a simple fabrication method and structure for GaO photodetectors with good doping uniformity and low fabrication temperature is of great significance for promoting the development of GaO photodetectors. Summary of the Invention

[0006] To overcome at least one of the defects described in the prior art, the present invention provides a gallium oxide photodetector and its fabrication method.

[0007] The present invention aims to solve the above-mentioned technical problems to at least some extent.

[0008] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0009] A method for fabricating a gallium oxide photodetector includes the following steps:

[0010] S1: Prepare a gallium oxide thin film doped with a predetermined element on the substrate surface;

[0011] S2: A predetermined region on the surface of a gallium oxide thin film doped with a predetermined element is simultaneously subjected to laser irradiation and ion bombardment in a vacuum environment to obtain a space charge region for charge transport.

[0012] S3: Prepare positive and negative electrodes on the surface of a gallium oxide thin film doped with a preset element to obtain a gallium oxide photodetector.

[0013] Further, step S1, the preparation of a gallium oxide thin film doped with a predetermined element on the substrate surface, includes:

[0014] Gallium oxide thin films doped with predetermined elements are prepared on a substrate using electron beam evaporation technology.

[0015] Further, step S2, wherein the predetermined area on the surface of the gallium oxide thin film is simultaneously subjected to laser irradiation and ion bombardment in a vacuum environment, includes:

[0016] The vacuum environment is a gas pressure below 1×10⁻⁶. -2 Pa;

[0017] The surface of a gallium oxide film doped with a preset element is irradiated by a laser with a preset optical power density and a preset irradiation time, and at the same time, the surface of the gallium oxide film doped with a preset ion beam is bombarded by ions with a preset ion beam.

[0018] The ion source used in the ion bombardment includes one or more combinations of nitrogen ions, oxygen ions, argon ions, boron ions, phosphorus ions, arsenic ions, germanium ions, and aluminum ions.

[0019] Further, in step S2, the laser irradiation and ion bombardment treatment are carried out at a preset temperature, the preset temperature range being 50 to 500°C.

[0020] Further, in step S2, a predetermined region on the surface of a gallium oxide thin film doped with a predetermined element is subjected to laser irradiation and ion bombardment in a vacuum environment to obtain a space charge region for charge transport. This includes: irradiating and bombarding a predetermined region on the surface of a gallium oxide thin film doped with a predetermined element with a predetermined element with a predetermined element, and obtaining a space charge region based on the boundary between the laser irradiation and ion bombardment.

[0021] Further, step S3, the fabrication of the positive and negative electrodes on the surface of the gallium oxide thin film, includes:

[0022] A positive electrode and a negative electrode are fabricated on the surface of a gallium oxide thin film doped with a preset element using magnetron sputtering technology. The positive electrode is used to connect to a positive voltage terminal, and the negative electrode is used to connect to a negative voltage terminal or a ground terminal.

[0023] A gallium oxide photodetector is used in the gallium oxide photodetector fabrication method, comprising: a substrate, a gallium oxide thin film, a space charge region, a positive electrode, and a negative electrode, wherein the gallium oxide thin film is disposed on the surface of the substrate, the space charge region is disposed on the gallium oxide thin film, and the positive electrode and the negative electrode are disposed on the surface of the gallium oxide thin film.

[0024] Furthermore, the space charge region is disposed between the positive electrode and the negative electrode.

[0025] Furthermore, the positive and negative electrode materials include any one of Au, Ti, ITO, Cu, Al, Ag, and two-dimensional atomic crystal thin films.

[0026] Furthermore, the two-dimensional atomic crystal thin film and the gallium oxide thin film form a heterostructure.

[0027] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0028] This invention prepares a gallium oxide thin film doped with a predetermined element on the substrate surface, modulates the electrical properties of the gallium oxide thin film, and lowers the crystallization temperature of gallium oxide. A predetermined region on the surface of the gallium oxide thin film is subjected to laser irradiation and ion bombardment treatment to control the carrier concentration and band structure of the gallium oxide thin film. A potential difference is formed between the gallium oxide thin film region treated by laser irradiation and ion bombardment and other regions to obtain a space charge region for charge transport. The space charge region improves the device operating voltage and charge collection efficiency, thereby preparing a high-sensitivity photodetector. Attached Figure Description

[0029] Figure 1 This is a flowchart of the gallium oxide photodetector fabrication method described in this invention;

[0030] Figure 2 This is a schematic diagram of the gallium oxide photodetector structure described in this invention;

[0031] Figure 3 This is a schematic diagram of a silicon-doped gallium oxide photodetector structure that simultaneously processes different widths using laser irradiation and ion bombardment, as described in this embodiment.

[0032] Figure 4 This is a schematic diagram of the interdigitated silicon-doped gallium oxide photodetector structure described in this embodiment;

[0033] In the figure: 1. Substrate; 2. Silicon-doped gallium oxide thin film; 3. Electrode; 4. Laser; 5. Ion beam; 6. Space charge region. Detailed Implementation

[0034] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0035] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions.

[0036] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings.

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] Example 1

[0039] A method for fabricating a gallium oxide photodetector, such as Figure 1 As shown, it includes the following steps:

[0040] S1: Prepare a gallium oxide thin film doped with a predetermined element on the substrate surface;

[0041] S2: A predetermined region on the surface of a gallium oxide thin film doped with a predetermined element is simultaneously subjected to laser irradiation and ion bombardment in a vacuum environment to obtain a space charge region for charge transport.

[0042] S3: Prepare positive and negative electrodes on the surface of a gallium oxide thin film doped with a preset element to obtain a gallium oxide photodetector.

[0043] In practical implementation, the structure of the gallium oxide photodetector is as follows: Figure 2 As shown, a gallium oxide thin film doped with a predetermined element is prepared on the substrate surface. The electrical properties of the gallium oxide thin film are controlled, and the crystallization temperature of gallium oxide is reduced. A predetermined region on the surface of the gallium oxide thin film doped with the predetermined element is subjected to laser irradiation and ion bombardment treatment to control the carrier concentration and band structure of the gallium oxide thin film. A potential difference is formed between the gallium oxide thin film region treated by laser irradiation and ion bombardment and other regions to obtain a space charge region for charge transport. The space charge region improves the device operating voltage and charge collection efficiency, thereby realizing a high-sensitivity photodetector.

[0044] Example 2

[0045] This embodiment, based on Embodiment 1, continues to disclose the following content:

[0046] Step S1, the preparation of a gallium oxide thin film doped with a predetermined element on the substrate surface includes:

[0047] Gallium oxide thin films doped with predetermined elements are prepared on a substrate using electron beam evaporation technology.

[0048] The substrate includes silicon wafers, glass, quartz, ceramics, photoluminescent crystal wafers, and P-type crystal wafers, etc.

[0049] Step S2, wherein the predetermined area on the surface of the gallium oxide thin film is subjected to laser irradiation and ion bombardment treatment in a vacuum environment, includes:

[0050] The vacuum environment is a gas pressure below 1×10⁻⁶. -2 Pa;

[0051] The surface of a gallium oxide film doped with a preset element is irradiated by a laser with a preset optical power density and a preset irradiation time, and at the same time, the surface of the gallium oxide film doped with a preset ion beam is bombarded by ions with a preset ion beam.

[0052] The ion source used in the ion bombardment includes one or more combinations of nitrogen ions, oxygen ions, argon ions, boron ions, phosphorus ions, arsenic ions, germanium ions, and aluminum ions.

[0053] In specific implementation, the doping elements of the gallium oxide doped with specific elements include Si, Mg, Ni, Zn, Ti, In, Sn, and Mn. The source material used in the corresponding vacuum deposition process consists of Ga2O3 and one or more oxides of the doping elements, namely SiO2, MgO, NiO, ZnO, TiO2, In2O3, SnO2, and MnO. The mass content of the oxides of the doping elements in the source material ranges from 1% to 50%. A one-step vacuum deposition process can prepare gallium oxide films doped with specific elements. Furthermore, the doping uniformity of gallium oxide films prepared using Ga2O3 and oxides of specific doping elements is high. In contrast, traditional preparation processes require the preparation of a gallium oxide film followed by techniques such as ion implantation or high-temperature thermal diffusion, and the doping depth and uniformity are difficult to control.

[0054] Example 3

[0055] Based on Examples 1 and 2, this embodiment continues to disclose the following content:

[0056] Step S3, the laser irradiation and ion bombardment treatment are carried out at a preset temperature, the preset temperature range being 50 to 500°C.

[0057] In the specific implementation process, the laser irradiation and ion bombardment treatments are carried out in a vacuum environment, and the vacuum level of the vacuum environment is within the range of 10. -7 ~10 -3 Pa, wherein the laser wavelength range is 200–1500 nm, and the optical power density ranges from 0.1–100 mW / cm². 2The ion source operating voltage range for the ion bombardment is 100–500V, the ion beam current range is 20–80mA, and the laser irradiation and ion bombardment treatment time is 1–200min.

[0058] Step S2 involves subjecting a predetermined region on the surface of a gallium oxide thin film doped with a predetermined element to laser irradiation and ion bombardment in a vacuum environment to obtain a space charge region for charge transport. This includes: subjecting a predetermined region on the surface of a gallium oxide thin film doped with a predetermined element to laser irradiation and ion bombardment, and obtaining the space charge region based on the boundary between the laser irradiation and ion bombardment.

[0059] In the specific implementation process, such as Figure 3 As shown, silicon-doped gallium oxide thin films of different widths (50 μm, 100 μm, 150 μm, and 200 μm) were simultaneously treated by laser irradiation and ion bombardment. After fabricating the aforementioned silicon-doped gallium oxide photodetectors, a positive voltage was applied to the positive electrode and the negative electrode was grounded, enabling their use for detecting photons such as ultraviolet light and X-rays. The irradiation width of the laser may affect the light absorption, photogenerated carrier generation, and transport processes on the film surface, thereby altering the sensitivity, response speed, and dynamic range of the photodetector. By precisely controlling the irradiation width of the laser, the photoresponse characteristics of the photodetector can be finely tuned. Furthermore, by changing the SiO2 content of the evaporation source material in the electron beam evaporation, the doping concentration and electrical properties of the gallium oxide thin film can be controlled; and by changing the laser power density and irradiation time, the crystallinity of the gallium oxide thin film can be controlled, thereby regulating the photoelectron collection efficiency and speed of the photodetector.

[0060] Step S3, the fabrication of the positive and negative electrodes on the surface of the gallium oxide thin film, includes:

[0061] A positive electrode and a negative electrode are fabricated on the surface of a gallium oxide thin film doped with a preset element using magnetron sputtering technology. The positive electrode is used to connect to a positive voltage terminal, and the negative electrode is used to connect to a negative voltage terminal or a ground terminal.

[0062] Example 4

[0063] Based on Examples 1, 2, and 3, this embodiment continues to disclose the following content:

[0064] In the specific implementation process, step one is to prepare a silicon-doped gallium oxide thin film. A silicon wafer with an area of ​​2cm × 2cm and a thickness of 1mm is used as the substrate. The silicon wafer substrate is ultrasonically cleaned sequentially with acetone, anhydrous ethanol, and water for 10 minutes. A silicon-doped gallium oxide thin film is then prepared on the silicon wafer substrate using electron beam evaporation technology at a deposition rate of 0.1nm / s and a thickness of 500nm. The evaporation source material used for electron beam evaporation is a mixture of Ga₂O₃ and SiO₂, with Ga₂O₃ having a purity of 99.998% and SiO₂ having a purity of 99.999%, and the mass content of SiO₂ ranging from 5% to 50%.

[0065] Step 2: Simultaneous treatment of silicon-doped gallium oxide thin films via laser irradiation and ion bombardment. The silicon-doped gallium oxide thin film sample is placed in a vacuum chamber, and the gallium oxide thin film between the positive and negative electrodes is irradiated with a 550 nm wavelength laser. The laser power density ranges from 0.1 to 100 mW / cm². 2 Simultaneously, ion bombardment technology was used to treat the gallium oxide thin film between the positive and negative electrodes. The operating voltage range of the ion source was 100–500V, and the ion beam current range was 20–80mA. The laser irradiation and ion bombardment treatment time was 1–200 min, and the vacuum degree of the vacuum chamber was 1×10⁻⁶. -5 Pa. Gallium oxide thin films doped with specific elements contain dopant atoms. By employing the principle of dopant-induced recrystallization, the crystallization temperature of gallium oxide thin films can be lowered, enabling the achievement of highly crystalline gallium oxide thin films at temperatures of 500℃ and below.

[0066] Step 3: Fabrication of positive and negative electrodes. Positive and negative electrodes were fabricated on the surface of a silicon-doped gallium oxide thin film using magnetron sputtering at a deposition rate of 30 nm / min. The electrode material was metallic Au, with an electrode length of 5 mm, a width of 2 mm, a thickness of 100 nm, and an electrode spacing of 200 μm.

[0067] After fabricating the silicon-doped gallium oxide photodetector described above, a positive voltage is applied to the positive electrode and the negative electrode is grounded, allowing it to be used for detecting photons such as ultraviolet light and X-rays. Furthermore, by changing the SiO2 content of the evaporation source material in the electron beam evaporation, the doping concentration and electrical properties of the gallium oxide film can be controlled. By changing the laser power density and irradiation time, the crystallinity of the gallium oxide film can be controlled, thereby regulating the photoelectron collection efficiency and speed of the photodetector.

[0068] Example 5

[0069] This embodiment, based on embodiments 1, 2, 3, and 4, further discloses the following content:

[0070] A gallium oxide photodetector, such as Figure 2As shown, a gallium oxide photodetector is applied in the gallium oxide photodetector fabrication method, comprising: a substrate 1, a gallium oxide thin film 2, a space charge region 6, a positive electrode and a negative electrode, wherein a gallium oxide thin film is disposed on the surface of the substrate, the space charge region 6 is disposed on the gallium oxide thin film, and the positive electrode and the negative electrode are disposed on the surface of the gallium oxide thin film.

[0071] The space charge region 6 is disposed between the positive electrode and the negative electrode.

[0072] The positive and negative electrode materials include any one of Au, Ti, ITO, Cu, Al, Ag, and two-dimensional atomic crystal thin films.

[0073] Using two-dimensional atomic crystal thin films as electrode materials can increase the light-receiving area by allowing photoelectrons to pass through.

[0074] The two-dimensional atomic crystal thin film and the gallium oxide thin film form a heterostructure, which increases the operating voltage and charge collection efficiency, and improves the photoelectric detection sensitivity.

[0075] Example 6

[0076] This embodiment, based on embodiments 1, 2, 3, 4, and 5, further discloses the following content:

[0077] like Figure 4 As shown, the positive and negative electrodes have an interdigitated structure. The positive and negative electrodes are fabricated into interdigitated structures, and the silicon-doped gallium oxide thin film 2 between the positive and negative electrodes undergoes patterned laser irradiation and ion bombardment treatment to obtain a space charge region 6. The shape of the space charge region matches that of the positive and negative electrodes. The interdigitated structure increases the contact area between the positive and negative electrodes, allowing for the effective collection of more photogenerated charges. Simultaneously, the presence of the space charge region 6 promotes charge separation and transport, further improving charge collection efficiency. This, in turn, increases the device's operating voltage and charge collection efficiency, thereby achieving a high-sensitivity photodetector.

[0078] By employing patterned laser irradiation and ion bombardment, the position and shape of the space charge region can be precisely controlled, thereby improving the photoelectric conversion efficiency of the device. Within the space charge region, the charge amount decreases rapidly due to the recombination of electrons and holes, simultaneously forming a high potential barrier region, i.e., an increased bandgap.

[0079] The positive and negative electrodes are fabricated in an alternating arrangement. This structure greatly increases the contact area between the electrodes, thus providing more charge transport channels. In addition, the interdigitated structure helps to optimize the electric field distribution, allowing photogenerated charges to be more effectively separated and directed to their respective electrodes under illumination.

[0080] The same or similar labels correspond to the same or similar parts;

[0081] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for fabricating a gallium oxide photodetector, characterized in that, Includes the following steps: S1: Prepare a gallium oxide thin film doped with a predetermined element on the substrate surface; S2: A predetermined region on the surface of a gallium oxide thin film doped with a predetermined element is simultaneously subjected to laser irradiation and ion bombardment in a vacuum environment, and a space charge region for charge transport is obtained based on the boundary between the laser irradiation and ion bombardment; wherein, the simultaneous laser irradiation and ion bombardment of the predetermined region on the surface of the gallium oxide thin film doped with the predetermined element in a vacuum environment includes: The vacuum environment is a gas pressure below 1 × 10⁻⁶. -2 Pa; The surface of a gallium oxide film doped with a preset element is irradiated by a laser with a preset optical power density and a preset irradiation time, and at the same time, the surface of the gallium oxide film doped with a preset ion beam is bombarded by ions with a preset ion beam. The ion source used in the ion bombardment includes one or more combinations of nitrogen ions, oxygen ions, argon ions, boron ions, phosphorus ions, arsenic ions, germanium ions, and aluminum ions. S3: Prepare positive and negative electrodes on the surface of a gallium oxide thin film doped with a preset element to obtain a gallium oxide photodetector.

2. The method for fabricating a gallium oxide photodetector according to claim 1, characterized in that, Step S1, the preparation of a gallium oxide thin film doped with a predetermined element on the substrate surface includes: Gallium oxide thin films doped with predetermined elements are prepared on a substrate using electron beam evaporation technology.

3. The method for fabricating a gallium oxide photodetector according to claim 1, characterized in that, Step S2, the laser irradiation and ion bombardment treatment are performed at a preset temperature, the preset temperature range being 50 ~ 500 ℃.

4. The method for fabricating a gallium oxide photodetector according to claim 1, characterized in that, Step S3, the preparation of positive and negative electrodes on the surface of a gallium oxide thin film doped with a preset element, includes: A positive electrode and a negative electrode are fabricated on the surface of a gallium oxide thin film doped with a preset element using magnetron sputtering technology. The positive electrode is used to connect to a positive voltage terminal, and the negative electrode is used to connect to a negative voltage terminal or a ground terminal.

5. A gallium oxide photodetector, characterized in that, The gallium oxide photodetector is applied to the gallium oxide photodetector fabrication method according to any one of claims 1 to 4, comprising: a substrate, a gallium oxide thin film, a space charge region, a positive electrode and a negative electrode, wherein the surface of the substrate is provided with a gallium oxide thin film, the gallium oxide thin film is provided with a space charge region, and the surface of the gallium oxide thin film is provided with a positive electrode and a negative electrode.

6. The gallium oxide photodetector according to claim 5, characterized in that, The space charge region is positioned between the positive and negative electrodes.

7. The gallium oxide photodetector according to claim 6, characterized in that, The positive and negative electrode materials include any one of Au, Ti, ITO, Cu, Al, Ag, and two-dimensional atomic crystal thin films.

8. The gallium oxide photodetector according to claim 7, characterized in that, The two-dimensional atomic crystal thin film and the gallium oxide thin film form a heterostructure.

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