Method for preparing P-type CuGa2O4 film

Abstract

The invention discloses a method for preparing a P-type CuGa2O4 film, relates to the fields of semiconductor materials, integrated circuits, photoelectric devices and the like, and realizes conversion from an intrinsic N type of a Ga2O3-based material to a P type. A pulse laser deposition technology and a tube furnace annealing technology are utilized, and the method comprises the following steps: firstly, bombarding a CuGa2O4 target material by using a high-energy laser in an ultrahigh vacuum environment, so that the target material is uniformly deposited on the surface of a substrate; and after the thin film is grown, putting a grown sample into a tubular furnace, introducing oxygen, annealing, repairing crystal lattices and making up for the defects of oxygen vacancies. The method is simple in preparation process, low in cost and short in required time, and the prepared CuGa2O4 film is high in quality and excellent in photoelectric property and can be applied to the field of photoelectric devices such as luminescent materials and photoelectric detectors.

Description

Technical Field

[0001] The present invention relates to the fields of semiconductor materials, integrated circuits and optoelectronic devices, and in particular to a method for preparing a P-type CuGa2O4 thin film by using a pulse laser deposition technology and a tube furnace annealing technology. Background Art

[0002] Gallium oxide (Ga2O3), as an emerging wide-bandgap semiconductor material, has attracted widespread attention due to its excellent electrical and optical properties. Gallium oxide has a bandgap of about 4.8 eV and is suitable for applications such as high-power electronic devices and ultraviolet light detectors. However, gallium oxide mainly exhibits N-type conductivity, which limits its application in certain heterostructure devices.

[0003] To overcome this limitation, researchers began to focus on CuGa2O4 thin films. CuGa2O4 is a wide bandgap semiconductor with a spinel structure, with a bandgap of about 4.4 eV, and its light absorption and emission properties are better than gallium oxide. Compared with gallium oxide, CuGa2O4 not only has P-type conductivity, but also exhibits higher catalytic activity and selectivity, making it suitable for a variety of applications such as optoelectronic devices, catalysis and sensors.

[0004] CuGa2O4 has a large bandgap and a high response to ultraviolet light, which is particularly important in the design of ultraviolet photodetectors and is of great significance in the fields of environmental monitoring, space exploration, and biological monitoring. CuGa2O4 has good thermal stability, which enables it to maintain stable photoelectric performance in high temperature environments, which is particularly important for detectors that need to work in harsh environments.

[0005] According to reports, studies have used chemical vapor deposition (CVD), aerosol-assisted CVD, solid-phase reaction, thermal decomposition, laser molecular beam epitaxy (L-MBE) and other technologies to synthesize CuGa2O4. However, these technologies have complex steps, slow synthesis time, or involve volatile precursors, or produce toxic byproducts. Based on this, pulsed laser deposition technology and tubular furnace annealing technology can be used to prepare P-type CuGa2O4 films with excellent performance, and can effectively avoid the above problems. Summary of the invention

[0006] The present invention provides a method for preparing a P-type CuGa2O4 film, which is used to solve the intrinsic N-type problem of Ga2O3 film, and can obtain gallium oxide-based materials with better light absorption and emission characteristics. It solves the problems of the previous CuGa2O4 film preparation method, such as complex process, low efficiency, poor film quality, and toxic byproducts.

[0007] The technical solution of the present invention is: A method for preparing a P-type CuGa2O4 thin film, characterized in that it mainly comprises the following steps: S1: Use acetone to ultrasonically clean the sapphire substrate, blow dry it with nitrogen after cleaning, install the sapphire substrate on the sample holder, and then place the sample holder and the sapphire substrate in the sample chamber of the pulsed laser deposition system. Use the mechanical pump and molecular pump to evacuate the vacuum until the vacuum reaches 6×10 -5 After the temperature is below pa, the sample holder and the sapphire substrate are sent into the preparation room as a whole; S2: The preparation process of P-type CuGa2O4 thin film is as follows: S21: Turn on the temperature control power supply of the pulsed laser deposition system, heat the sapphire substrate to 500°C, adjust the current knob to 5A, turn off the preparation chamber ionization vacuum gauge, preheat the laser in advance, set the laser energy to 300mJ and the frequency to 10Hz, and adjust the distance between the sapphire substrate and the target to 5cm; S22: Turn on the pulse laser to bombard the CuGa2O4 target, which is made of CuO and Ga2O3 mixed in a ratio of 1:1 and then sintered and pressed at high temperature. The growth thickness of the CuGa2O4 film on the sapphire substrate is observed by the film thickness monitor. When the film grows to 400nm, turn off the laser, and then start to cool the sapphire substrate. When the temperature drops below 100℃, turn on the ionization vacuum gauge in the preparation chamber. When the vacuum degree reaches 2×10 -6 After pa, the sapphire substrate on which the CuGa2O4 film has been grown is returned to the sample injection chamber and taken out; S23: Put the sample taken out in S22 into a tubular furnace, evacuate it with a mechanical pump, and when the vacuum reaches about 5 mbarr, open the oxygen valve and the oxygen flowmeter at the same time, control the oxygen flow rate to about 30 ml / min, and pass oxygen for about 10 minutes. After the oxygen pressure in the furnace is balanced, start heating from room temperature to 800°C, set the heating rate to 10°C / min, and take 80 minutes. After stabilizing for 10 minutes, continue to heat to 1000°C, with a heating rate of 5°C / min, and take 40 minutes. After the heating is completed, anneal for 60 minutes; S24: After the S23 annealing is completed, close the oxygen valve, return the oxygen flow meter knob to zero, then turn off the mechanical pump, and take out the sample after naturally cooling to room temperature to obtain a P-type CuGa2O4 film on the sapphire substrate.

[0008] The step S2 uses pulse laser deposition technology and tube furnace annealing technology.

[0009] The present invention has the following beneficial effects: the technical solution of the present invention has simple operation steps, low cost, short preparation time, almost zero pollution to the environment during the production process, and is conducive to sustainable development. The P-type CuGa2O4 thin film prepared by this solution has good crystallinity, dense film quality, excellent light absorption and emission characteristics, meets the demand for P-type materials in the preparation of optoelectronic devices, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The present invention is a process flow chart of the preparation process.

[0011] Figure 2 This is a scanning electron microscope image of the surface morphology of P-type CuGa2O4 prepared by the preparation process of the present invention.

[0012] Figure 3 This is the X-ray diffraction pattern of the P-type CuGa2O4 film prepared by the preparation process of the present invention. DETAILED DESCRIPTION

[0013] Specific implementation method: A method for preparing a P-type CuGa2O4 thin film is completed by the following steps: S1: Use acetone to ultrasonically clean the sapphire substrate, blow dry it with nitrogen after cleaning, install the sapphire substrate on the sample holder, and then place the sample holder and the sapphire substrate in the sample chamber of the pulsed laser deposition system. Use the mechanical pump and molecular pump to evacuate the vacuum until the vacuum reaches 6×10 -5 After the temperature is below pa, the sample holder and the sapphire substrate are sent into the preparation room as a whole; S2: The preparation process of P-type CuGa2O4 thin film is as follows: S21: Turn on the temperature control power supply of the pulsed laser deposition system, heat the sapphire substrate to 500°C, adjust the current knob to 5A, turn off the preparation chamber ionization vacuum gauge, preheat the laser in advance, set the laser energy to 300mJ and the frequency to 10Hz, and adjust the distance between the sapphire substrate and the target to 5cm; S22: Turn on the pulse laser to bombard the CuGa2O4 target, which is made of CuO and Ga2O3 mixed in a ratio of 1:1 and then sintered and pressed at high temperature. The growth thickness of the CuGa2O4 film on the sapphire substrate is observed by the film thickness monitor. When the film grows to 400nm, turn off the laser, and then start to cool the sapphire substrate. When the temperature drops below 100℃, turn on the ionization vacuum gauge in the preparation chamber. When the vacuum degree reaches 2×10 -6 After pa, the sapphire substrate on which the CuGa2O4 film has been grown is returned to the sample injection chamber and taken out; S23: Put the sample taken out in S22 into a tubular furnace, evacuate it with a mechanical pump, and when the vacuum reaches about 5 mbarr, open the oxygen valve and the oxygen flowmeter at the same time, control the oxygen flow rate to about 30 ml / min, and pass oxygen for about 10 minutes. After the oxygen pressure in the furnace is balanced, start heating from room temperature to 800°C, set the heating rate to 10°C / min, and take 80 minutes. After stabilizing for 10 minutes, continue to heat to 1000°C, with a heating rate of 5°C / min, and take 40 minutes. After the heating is completed, anneal for 60 minutes; S24: After the S23 annealing is completed, close the oxygen valve, return the oxygen flow meter knob to zero, then turn off the mechanical pump, and take out the sample after naturally cooling to room temperature to obtain a P-type CuGa2O4 film on the sapphire substrate.

[0014] In this embodiment, the sapphire substrate described in step S1 can also be replaced by other substrates with a small lattice mismatch with the P-type CuGa2O4 thin film.

[0015] In this embodiment, the laser parameters described in step S21 and the distance between the substrate and the target can be adjusted according to actual conditions.

[0016] In this embodiment, the mixing ratio of the pressed target material described in step S22 can be adjusted according to actual conditions.

[0017] In this embodiment, the oxygen flow rate described in step S23 can be adjusted according to actual conditions.

[0018] It should be pointed out that the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, additions or substitutions made by technicians in this technical field within the scope of the description of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing a P-type CuGa2O4 thin film, characterized in that: The main steps include: S1: Use acetone to ultrasonically clean the sapphire substrate, blow dry it with nitrogen after cleaning, install the sapphire substrate on the sample holder, and then place the sample holder and the sapphire substrate in the sample chamber of the pulsed laser deposition system. Use the mechanical pump and molecular pump to evacuate the vacuum until the vacuum reaches 6×10 -5 After the temperature is below pa, the sample holder and the sapphire substrate are sent into the preparation room as a whole; S2: The preparation process of P-type CuGa2O4 thin film is as follows: S21: Turn on the temperature control power supply of the pulsed laser deposition system, heat the sapphire substrate to 500°C, adjust the current knob to 5A, turn off the preparation chamber ionization vacuum gauge, preheat the laser in advance, set the laser energy to 300mJ and the frequency to 10Hz, and adjust the distance between the sapphire substrate and the target to 5cm; S22: Turn on the pulse laser to bombard the CuGa2O4 target, which is made of CuO and Ga2O3 mixed in a ratio of 1:1 and then sintered and pressed at high temperature. The growth thickness of the CuGa2O4 film on the sapphire substrate is observed by the film thickness monitor. When the film grows to 400nm, turn off the laser, and then start to cool the sapphire substrate. When the temperature drops below 100℃, turn on the ionization vacuum gauge in the preparation chamber. When the vacuum degree reaches 2×10 -6 After pa, the sapphire substrate on which the CuGa2O4 film has been grown is returned to the sample injection chamber and taken out; S23: Put the sample taken out in S22 into a tubular furnace, evacuate it with a mechanical pump, and when the vacuum reaches about 5 mbarr, open the oxygen valve and the oxygen flowmeter at the same time, control the oxygen flow rate to about 30 ml / min, and pass oxygen for about 10 minutes. After the oxygen pressure in the furnace is balanced, start heating from room temperature to 800°C, set the heating rate to 10°C / min, and take 80 minutes. After stabilizing for 10 minutes, continue to heat to 1000°C, with a heating rate of 5°C / min, and take 40 minutes. After the heating is completed, anneal for 60 minutes; S24: After the S23 annealing is completed, close the oxygen valve, return the oxygen flow meter knob to zero, then turn off the mechanical pump, and take out the sample after naturally cooling to room temperature to obtain a P-type CuGa2O4 film on the sapphire substrate.

2. A method for preparing a P-type CuGa2O4 thin film according to claim 1, characterized in that: The step S2 uses pulse laser deposition technology and tube furnace annealing technology.

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