Ga2O3 / GaN heterojunction and preparation method and application thereof
By depositing Sn on GaN thin films and reacting it with elemental Ga, Ga2O3/GaN heterojunctions were prepared, solving the problems of high cost and rough films in the prior art. This enabled the simple and low-cost preparation of Ga2O3/GaN heterojunctions and the dual-band response characteristics of photodetectors.
Patent Information
- Application Number
- CN202511275571.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-12-12
AI Technical Summary
Existing technologies are costly and inefficient in preparing Ga2O3/GaN heterojunctions, and the grown Ga2O3 films are rough, making it difficult to meet the needs of scientific research and the market.
Sn is deposited on a portion of the GaN thin film, and then reacted with Ga elemental at 850℃~920℃. During the reaction, Sn evaporates, activates the surface states of the substrate, grows a Ga2O3 thin film, and forms a Ga2O3/GaN heterojunction.
The preparation method is simple and low-cost, and the grown Ga2O3 film is smooth and flat, meeting the experimental requirements. The Ga2O3/GaN heterojunction photodetector has dual-band response characteristics and good repeatability.
Smart Images
Figure CN121109958A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor material preparation technology, and more specifically to a Ga2O3 / GaN heterojunction, its preparation method, and its application. Background Technology
[0002] Semiconductor materials have undergone several generations of development. First-generation semiconductor materials, such as silicon (Si) and germanium (Ge), laid the foundation for the modern electronics industry, but their performance gradually became insufficient to meet the demands of technological advancements. Second-generation semiconductor materials, such as gallium arsenide (GaAs), made progress in high-frequency and high-speed devices. Third-generation semiconductor materials, represented by gallium nitride (GaN) and silicon carbide (SiC), possess advantages such as wide bandgap, high breakdown electric field, and high electron mobility, making them a hot research topic.
[0003] Photodetectors, which convert light signals into electrical signals, are key components in optoelectronic systems. Currently, photodetectors have evolved to detect infrared (IR), visible, and ultraviolet (UV) light. Gallium oxide (Ga2O3), as an ultrawide bandgap semiconductor material with a bandgap of 4.9 eV, offers new opportunities for improving photodetector performance. GaN, with a direct bandgap of approximately 3.4 eV, and Ga2O3, each possessing excellent properties, combine to form the Ga2O3 / GaN photodetector, which is expected to integrate the advantages of both and overcome the performance limitations of traditional detectors. By constructing a built-in electric field at the heterojunction interface, Ga2O3 and GaN effectively improve the photogenerated carrier separation efficiency, responsivity, and detectivity, achieving key performance characteristics such as dual-band detection and low dark current.
[0004] Ga2O3 / GaN heterojunctions were prepared using methods such as MOCVD, magnetron sputtering, and annealing. The first two methods are costly and inefficient, while the latter method produces Ga2O3 with a relatively rough thickness and a surface dominated by nanoparticles, which cannot meet the current needs of scientific research and the market. Summary of the Invention
[0005] To address the above problems, this invention provides a Ga2O3 / GaN heterojunction, its preparation method, and its application. The preparation method is simple and low-cost, and the grown Ga2O3 film is relatively smooth and flat, meeting experimental requirements.
[0006] The first objective of this invention is to provide a method for preparing a Ga2O3 / GaN heterojunction, comprising the following steps: Sn metal is vapor-deposited onto a portion of the GaN thin film to obtain Sn-deposited GaN.
[0007] In an air atmosphere, Sn-plated GaN is reacted with elemental Ga at 850℃~920℃. During the reaction, elemental Ga grows a Ga2O3 film in the Sn-containing region, and finally a Ga2O3 / GaN heterojunction is obtained.
[0008] In a preferred embodiment of the present invention, the reaction time is 40 min to 60 min.
[0009] In a preferred embodiment of the present invention, the reaction time is 50 min.
[0010] In a preferred embodiment of the present invention, the reaction temperature is 900°C.
[0011] In a preferred embodiment of the present invention, the air flow rate is 60 sccm to 100 sccm.
[0012] In a preferred embodiment of the present invention, the vapor deposition current is 80A~90A during vapor deposition.
[0013] In a preferred embodiment of the present invention, the vapor deposition time is 30s to 40s.
[0014] The second objective of this invention is to provide a method for preparing Ga2O3 / GaN heterojunctions.
[0015] A third objective of this invention is to provide the application of the aforementioned Ga2O3 / GaN heterojunction in the fabrication of photodetectors.
[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention first involves depositing Sn onto a portion of a GaN thin film, then reacting it with elemental Ga at 850℃~920℃. During the reaction, the deposited Sn evaporates, simultaneously activating the surface states of the substrate and enhancing gallium oxide adsorption, thereby obtaining a Ga2O3 / GaN heterojunction. The method of this invention is simple to operate and low in cost. Furthermore, the prepared thin film has a thickness of 240 nm and is relatively smooth and flat. Attached Figure Description
[0017] Figure 1 This is a scan image of the Ga2O3 / GaN material prepared in Example 1.
[0018] Figure 2 This is a scan image of the Ga2O3 / GaN material prepared in Comparative Example 1.
[0019] Figure 3 The image shows the IT diagram of the Ga2O3 / GaN heterojunction photodetector prepared in Example 1. Detailed Implementation
[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] This invention prepares a Ga2O3 / GaN heterojunction. In the preparation process, Sn metal is deposited onto a portion of a GaN thin film to obtain Sn-plated GaN. Part of the Sn-plated GaN has Sn deposited, while the other part does not. Then, the Sn-plated GaN is reacted with elemental Ga in air at 850℃~920℃. During the reaction, elemental Ga grows a Ga2O3 thin film in the Sn-containing regions, and the deposited Sn evaporates, simultaneously activating the surface states of the substrate and increasing gallium oxide adsorption. In the Sn-free regions, Ga2O3 does not grow, thus obtaining the Ga2O3 / GaN heterojunction. This invention is simple to operate, eliminating the need for costly methods such as MOCVD, magnetron sputtering, and annealing. Furthermore, the Ga2O3 thin film grown on GaN using this invention is smooth and flat, meeting application requirements.
[0022] Example 1 (1) A vacuum evaporation apparatus was used to evaporate the GaN thin film with Sn metal. During the evaporation, a high-temperature resistant tape was used as a mask to cover half of the GaN thin film. The evaporation current was 80A, the evaporation time was 40s, and the distance between the Sn metal and the GaN thin film was 10cm. After the evaporation was completed, the Sn-plated GaN was obtained.
[0023] (2) The 5mm×5mm Sn-coated GaN obtained in step (1) was reacted with 20mg of elemental Ga in a tube furnace. Under the condition of 80sccm of air, the temperature was raised to 900℃ and held for 50min. The temperature was then lowered to 550℃ at a cooling rate of 20℃ / min and cooled to room temperature. This allowed Ga2O3 films to grow in the Sn-containing regions, while no Ga2O3 films grew in the Sn-free regions, ultimately yielding Ga2O3 / GaN material. The scan image is shown below. Figure 1 As shown, the film is relatively smooth and flat.
[0024] (3) Electrodes are fabricated on the Ga2O3 / GaN material with and without thin film obtained in step (2). Specifically, In / Ga electrodes are dotted on the Ga2O3 / GaN material with and without thin film using an indium dotting pen to obtain a Ga2O3 / GaN heterojunction photodetector.
[0025] Example 2 (1) A vacuum evaporation apparatus was used to evaporate the GaN thin film with Sn metal. During the evaporation, a high-temperature resistant tape was used as a mask to cover half of the GaN thin film. The evaporation current was 90A, the evaporation time was 30s, and the distance between the Sn metal and the GaN thin film was 10cm. After the evaporation was completed, the Sn-plated GaN was obtained.
[0026] (2) The 5mm×5mm Sn-plated GaN obtained in step (1) is placed in a tube furnace for reaction with 15mg of Ga element. Under the condition of 90sccm of air, the temperature is raised to 850℃ and held for 40min. The temperature is then lowered to 450℃ at a cooling rate of 20℃ / min and cooled to room temperature. This allows Ga element to grow Ga2O3 film in the Sn-containing region and no Ga2O3 film to grow in the Sn-free region, thus obtaining Ga2O3 / GaN material.
[0027] (3) Electrodes are fabricated on the Ga2O3 / GaN material with and without thin film obtained in step (2). Specifically, In / Ga electrodes are dotted on the Ga2O3 / GaN material with and without thin film using an indium dotting pen to obtain a Ga2O3 / GaN heterojunction photodetector.
[0028] Example 3 (1) A vacuum evaporation apparatus was used to evaporate the GaN thin film with Sn metal. During the evaporation, a high-temperature resistant tape was used as a mask to cover half of the GaN thin film. The evaporation current was 85A, the evaporation time was 35s, and the distance between the Sn metal and the GaN thin film was 10cm. After the evaporation was completed, the Sn-plated GaN was obtained.
[0029] (2) The 5mm×5mm Sn-plated GaN obtained in step (1) is placed in a tube furnace and reacted with 15mg of Ga elemental. Under the condition of 100sccm of air, the temperature is raised to 920℃ and held for 40min. The temperature is then lowered to 500℃ at a cooling rate of 20℃ / min and cooled to room temperature. This allows Ga elemental to grow Ga2O3 film in the Sn-containing region and no Ga2O3 film to grow in the Sn-free region, thus finally obtaining Ga2O3 / GaN material.
[0030] (3) Electrodes are fabricated on the Ga2O3 / GaN material with and without thin film obtained in step (2). Specifically, In / Ga electrodes are dotted on the Ga2O3 / GaN material with and without thin film using an indium dotting pen to obtain a Ga2O3 / GaN heterojunction photodetector.
[0031] Example 4 (1) A vacuum evaporation apparatus was used to evaporate the GaN thin film with Sn metal. During the evaporation, a high-temperature resistant tape was used as a mask to cover half of the GaN thin film. The evaporation current was 80A, the evaporation time was 35s, and the distance between the Sn metal and the GaN thin film was 10cm. After the evaporation was completed, the Sn-plated GaN was obtained.
[0032] (2) The 5mm×5mm Sn-plated GaN obtained in step (1) is placed in a tube furnace and reacted with 15mg of Ga elemental. Under the condition of 100sccm of air, the temperature is raised to 900℃ and held for 40min. The temperature is then lowered to 500℃ at a cooling rate of 20℃ / min and cooled to room temperature. This allows Ga elemental to grow Ga2O3 film in the Sn-containing region and no Ga2O3 film to grow in the Sn-free region, thus finally obtaining Ga2O3 / GaN material.
[0033] (3) Electrodes are fabricated on the Ga2O3 / GaN material with and without thin film obtained in step (2). Specifically, In / Ga electrodes are dotted on the Ga2O3 / GaN material with and without thin film using an indium dotting pen to obtain a Ga2O3 / GaN heterojunction photodetector.
[0034] Comparative Example 1 (1) A vacuum evaporation apparatus was used to evaporate the GaN thin film with Au metal. During the evaporation, a high-temperature resistant tape was used as a mask to cover half of the GaN thin film. The evaporation current was 80A, the evaporation time was 40s, and the distance between the Au metal and the GaN thin film was 10cm. After the evaporation was completed, Au-plated GaN was obtained.
[0035] (2) The 5mm×5mm Au-plated GaN obtained in step (1) and 20mg of Ga element were placed in a tube furnace for reaction. Under the condition of 80sccm of air, the temperature was raised to 900℃ and held for 50min. The temperature was then lowered to 550℃ at a cooling rate of 20℃ / min and cooled to room temperature. This allowed Ga element to grow Ga2O3 film in the Au-containing area and no Ga2O3 film to grow in the Au-free area, thus obtaining Ga2O3 / GaN material.
[0036] The scanning results of the Ga2O3 / GaN material prepared in Comparative Example 1 are as follows: Figure 2 As shown, the morphology is a disordered nanowire structure. The contact between the wires may cause short circuits, which will ultimately affect the device performance. This is because Sn will evaporate during the preparation process to increase the surface adhesion energy of the substrate, while Au will not evaporate and will form droplets, which will eventually grow into nanowires according to the VSL mechanism.
[0037] The performance of Examples 1 to 4 is similar. The following test will only take Example 1 as an example.
[0038] like Figure 3 As shown, the photodetector device prepared in Embodiment 1 of the present invention has dual-band response characteristics and good repeatability and responsiveness. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.
[0039] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A method for preparing a Ga2O3 / GaN heterojunction, characterized in that, Includes the following steps: Sn metal is vapor-deposited onto a portion of the GaN thin film to obtain Sn-deposited GaN; In an air atmosphere, Sn-plated GaN is reacted with elemental Ga at 850℃~920℃. During the reaction, elemental Ga grows a Ga2O3 film in the Sn-containing region, and finally a Ga2O3 / GaN heterojunction is obtained.
2. The method for preparing a Ga2O3 / GaN heterojunction according to claim 1, characterized in that, The reaction time is 40 min to 60 min.
3. The method for preparing a Ga2O3 / GaN heterojunction according to claim 2, characterized in that, The reaction time is 50 minutes.
4. The method for preparing a Ga2O3 / GaN heterojunction according to claim 1, characterized in that, The reaction temperature is 900℃.
5. The method for preparing a Ga2O3 / GaN heterojunction according to claim 1, characterized in that, The air flow rate is 60 sccm to 100 sccm.
6. The method for preparing a Ga2O3 / GaN heterojunction according to claim 1, characterized in that, During vapor deposition, the vapor deposition current is 80A~90A.
7. The method for preparing a Ga2O3 / GaN heterojunction according to claim 1, characterized in that, During vapor deposition, the deposition time is 30s~40s.
8. A Ga2O3 / GaN heterojunction prepared by the preparation method according to claims 1 to 7.
9. The application of the Ga2O3 / GaN heterojunction as described in claim 8 in the fabrication of a photodetector.