Method for growing gallium oxide film by using gallium antimonide metal source
By using a gallium antimonide metal source to grow gallium oxide thin films in low-pressure chemical vapor deposition, the problems of expensive equipment and safety hazards caused by high-temperature growth are solved, and high-quality gallium oxide thin films can be grown at lower temperatures.
Patent Information
- Application Number
- CN202511252099.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-03
- Publication Date
- 2025-12-02
AI Technical Summary
Existing technologies require high-temperature environments to grow gallium oxide thin films, resulting in expensive equipment and safety hazards, while also producing films with low purity and crystallinity.
Gallium antimonide metal compound was used as gallium source, and gallium oxide thin film was grown in low-pressure chemical vapor deposition with oxygen and argon. The reaction temperature was reduced and gallium oxide and antimony oxide were generated by the gas phase reaction of gallium antimonide and oxygen.
High-quality gallium oxide films can be grown at lower temperatures, which improves the purity and crystallinity of the films, reduces production costs, and simplifies the process.
Smart Images
Figure CN121046940A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of low-pressure chemical vapor deposition (LPVCD) thin film growth technology, specifically a method for growing gallium oxide thin films using a gallium antimonide metal source. Background Technology
[0002] Gallium oxide (GaO) is an ultra-wide bandgap semiconductor material. Research has revealed six crystal structures for GaO, with the β-phase exhibiting a complex monoclinic crystal structure, high thermal stability, and relatively stable chemical properties. GaO boasts a bandgap of 4.9 eV, which determines its strong absorption capability for wavelengths up to 250 nm. Currently, many solar-blind ultraviolet detectors are based on silicon. However, due to the narrow bandgap of silicon (1.2 eV), filters are required during use, resulting in high costs and low efficiency. Therefore, GaO has a natural advantage in solar-blind ultraviolet photodetectors.
[0003] Currently, various epitaxial techniques have been developed for growing β-phase gallium oxide, such as metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), low-pressure chemical vapor deposition (LPCVD), and pulsed laser deposition (PLD). MOCVD utilizes organometallic compounds in gaseous molecular form, using H2 as the carrier gas, and forms compound semiconductors through thermal decomposition reactions. This method has a relatively fast deposition rate, but the reaction source is generally a toxic, flammable, explosive, and expensive organometallic compound. Furthermore, MOCVD experimental equipment is expensive, making the experiment both dangerous and costly. Molecular beam epitaxy (MBE), under ultra-high vacuum conditions, heats the elements of the target thin film composition in their respective molecular beam furnaces to form directional molecular beams that are then incident on a heated substrate for thin film growth. This method requires a high degree of vacuum and can produce thin films with fewer impurities, but it is inflexible in selecting the target source, has a slow deposition rate, and results in low sample crystallinity. While pulsed laser deposition (PLD) has a simpler experimental process and principle, its deposition rate is low, and it is limited by the low temperature of the substrate, resulting in poor crystallinity of the obtained material, requiring post-annealing to improve the crystallinity. Low-pressure chemical vapor deposition (LPCVD) generally uses elemental metals or metal compounds as the reaction source, preparing semiconductor materials using reaction gases in a low-pressure, high-temperature environment. The LPCVD experimental environment can improve the diffusion coefficient and mean free path of the reaction gases, which is beneficial for mass transport, allowing the reaction source to be rapidly deposited onto the substrate surface. Thanks to the lower gas pressure, impurities and reaction byproducts can quickly leave the reaction zone, improving production efficiency. Summary of the Invention
[0004] The purpose of this invention is to provide a process for epitaxial gallium oxide based on gallium antimonide metal compound source, which solves the problem that epitaxial gallium oxide needs to be carried out in a high-temperature environment. The gallium source used is gallium antimonide metal compound, which reduces the growth temperature of the reaction and allows for the epitaxial growth of high-quality thin films under lower temperature conditions.
[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a process for epitaxial gallium oxide based on gallium antimonide metal compound source, using gallium antimonide as gallium metal source, oxygen as oxygen source, and argon as carrier gas, to grow gallium oxide epitaxial thin films through low-pressure gas phase chemical reaction.
[0006] Specifically, the following steps are included: (1) Substrate pretreatment: The substrate is cleaned with a mixture of concentrated sulfuric acid and hydrogen peroxide (volume ratio 3:1 to 5:1) and deionized water to remove surface impurities, which helps the adsorption of gallium oxide molecules in the reaction process. (2) Chamber cleaning: Place the substrate and gallium antimonide into the tube furnace, close the furnace chamber and repeatedly evacuate and introduce argon five times to ensure the cleanliness of the reaction chamber gas; (3) Temperature and gas control: Turn on the heating system and continuously introduce argon gas. After reaching the set temperature, introduce oxygen gas. The oxygen gas reacts with gallium antimonide gas in the gas phase under high temperature to generate gallium oxide and antimony oxide.
[0007] (4) Chamber cooling: After the reaction is complete, stop the oxygen supply, set the cooling program to automatically cool down to room temperature, open the chamber and take out the gallium oxide epitaxial film.
[0008] Further, in step (1), the substrate surface is ultrasonically cleaned with a mixed solution of concentrated sulfuric acid and hydrogen peroxide (volume ratio 3:1 to 5:1) to remove stains from the substrate surface. The substrate is one of gallium oxide, sapphire, silicon, gallium arsenide, diamond, and gallium nitride, preferably gallium oxide or sapphire. The ultrasonic cleaning time is 5-40 minutes, preferably 10-20 minutes.
[0009] Further, in step (2), gallium antimonide powder and substrate are placed in the same quartz boat, and the quartz boat is placed in a tube furnace; the furnace cavity is closed, the argon gas and vacuum device are turned on, the flow rate of argon gas is set to 50 to 300 sccm, preferably 150 to 200 sccm, the vacuum device is kept on continuously, and the argon gas switch is turned on and off five times to ensure the cleanliness of the gas in the reaction chamber.
[0010] Further, in step (3), the temperature of the gas phase chemical reaction is 700-1000℃; preferably, the temperature of the gas phase chemical reaction is 720-800℃. In this temperature range, gallium oxide, as a solid compound molecule, is attached to the substrate to grow and form a gallium oxide thin film, and antimony oxide, as a gaseous compound molecule, is discharged from the reaction chamber along with the carrier gas.
[0011] Furthermore, in step (3), oxygen is used as an oxygen source to participate in the reaction, and argon is used as a carrier gas to carry the reaction byproducts out of the reaction chamber. The flow rate ratio of oxygen to argon is 1:4-1:100. Among them, the oxygen flow rate is 1-100 sccm, preferably 5-50 sccm, and the argon flow rate is 50-500 sccm, preferably 100-200 sccm.
[0012] Furthermore, in step (4), after the experiment ends, a cooling gradient is set, and the equipment is cooled down slowly, which is conducive to the release of stress. The cooling time is 200-600 minutes, preferably 400 to 500 minutes.
[0013] Compared with the prior art, the beneficial effects of the present invention are: This invention uses gallium antimonide as the gallium metal source and has a relatively low decomposition temperature. At 700 °C, gallium antimonide can decompose into antimony atoms and gallium atoms, which combine with oxygen to generate gallium oxide and antimony oxide.
[0014] This invention proposes a novel β-Ga2O3 thin film epitaxy process, using gallium antimonide as the reaction source. This process eliminates the need for gallium oxide powder and metallic gallium particles in the β-Ga2O3 thin film growth, reducing the growth temperature and enabling growth at lower temperatures. The reaction byproducts are treated as gases and directly removed from the reaction apparatus, avoiding film contamination. This results in higher purity and denser films. Furthermore, the preparation method is simple and has low production costs, which is beneficial for production and research promotion. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of a low-pressure chemical vapor deposition furnace using the method of the present invention; Figure 2 This is a flowchart of gallium oxide growth according to the present invention; Figure 3 This is a surface image of gallium oxide obtained using a scanning electron microscope (SEM) in Example 1; Figure 4 This is a surface image of gallium oxide obtained using a scanning electron microscope (SEM) in Example 2; Figure 5 This is a surface image of gallium oxide obtained using a scanning electron microscope (SEM) in Example 3; Figure 6This is a scanning electron microscope (SEM) image of gallium oxide surface in Comparative Example 1; Figure 7 The images show X-ray diffraction (XRD) analysis of gallium oxide in Examples 1, 2, 3 and Comparative Example 1.
[0016] Explanation of reference numerals in the attached figures In the diagram: 01 is the reactor, 02 is the heating device, 03 is the quartz boat, 04 is gallium antimonide powder, 05 is the substrate, 06 is argon gas, 07 is oxygen gas, and 08 is the exhaust gas treatment device. Detailed Implementation
[0017] 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.
[0018] A schematic diagram of the structure of the method of the present invention in a low-pressure chemical vapor deposition furnace is shown below. Figure 1 As shown, it includes: a reactor 01, a heating device 02, a quartz boat containing the reaction source and substrate 03, gallium antimonide powder as the reaction source 04, a substrate (sapphire Al2O3) 05, argon as the carrier gas 06, oxygen as the oxygen source 07, and a tail gas treatment device for the reactor 08.
[0019] This invention provides a fabrication process for patterned composite substrates and gallium oxide epitaxy, such as... Figure 2 As shown, the method includes the following steps: S101, Substrate Pretreatment It should be noted that the substrate needs to be cleaned before epitaxial growth. The specific cleaning steps include: immersing the substrate in a mixed solution of concentrated sulfuric acid (H2SO4, 98%) and hydrogen peroxide (H2O2, 30%) (volume ratio 3:1 to 5:1) at a temperature of 100 to 150°C, ultrasonically cleaning for 10 to 30 minutes to remove surface organic matter and particles, treating with deionized water with a water resistance of 18 megohms, immersing for 100 to 1500 seconds, and then drying it with a nitrogen gun. This removes stains from the substrate surface, which is beneficial for gallium oxide epitaxy. The substrate can be one of sapphire, silicon, gallium oxide, gallium arsenide, diamond, or gallium nitride.
[0020] S102, Chamber washing It should be noted that pre-experimental preparations need to be completed before gas washing. Weigh 2 to 5 grams of gallium antimonide powder and arrange the substrate and powder in specific positions, such as... Figure 1As shown, the quartz boat is placed in the tube furnace, the vacuum device and the argon gas inlet device are turned on, the inlet flow rate is set to 150 to 200 sccm, and the inlet flow is continued for 30 seconds. The switching process is repeated five times to ensure that the gas in the chamber is clean enough to avoid contamination of the reaction process by impurities in the air.
[0021] S103, Temperature and Gas Control; It should be noted that after the gas washing is completed, the heating time and temperature are set. The temperature setting directly affects the degree of reaction. The heating time is 40 to 80 minutes, and the set temperature is 720 to 800 degrees Celsius. During the heating process, argon gas is continuously introduced, and the set argon gas flow rate is 100 to 200 sccm. After the temperature reaches the set temperature, a certain amount of oxygen is introduced, and the set oxygen flow rate is 5 to 50 sccm. After the experiment is completed, the oxygen introduction is immediately stopped, and the argon gas introduction is maintained.
[0022] S104, Chamber cooling.
[0023] It should be noted that a large amount of heat will accumulate during the gallium oxide epitaxy process. If a slow cooling curve is not set, the stress of gallium oxide cannot be released, which will affect the crystal quality. After the experiment, the cooling time is set to 400 to 500 minutes. After the cooling time is over, the vacuum device is turned off and the argon gas supply is stopped. The cavity is opened and the quartz boat is taken out to complete the gallium oxide epitaxy.
[0024] The method for growing gallium oxide thin films using gallium antimonide metal source described in this embodiment of the invention employs LPCVD technology. Under a low-pressure experimental environment, the diffusion coefficient and mean free path of the reactant gas can be improved, which is beneficial for mass transport. The reaction source can be rapidly deposited onto the substrate surface, and impurities and reaction byproducts can be quickly removed from the reaction zone, improving production efficiency. Regarding material selection, gallium antimonide is used instead of metallic gallium particles, reducing the temperature required for gallium oxide growth and saving energy and time. The established cooling curve after the experiment allows for stress release during gallium oxide growth, improving crystal quality. Example 1
[0025] S101, Substrate Pretreatment Before epitaxial growth, the substrate is cleaned. The specific cleaning steps include: immersing the substrate in a solution of concentrated sulfuric acid and hydrogen peroxide in a 5:1 ratio at 100 degrees Celsius, ultrasonically cleaning for 15 minutes to remove surface organic matter and particles, treating with deionized water with a water resistance of 18 megohms for 600 seconds, and then drying it with a nitrogen gun. This removes stains from the substrate surface, which is beneficial for gallium oxide epitaxy. The substrate is sapphire.
[0026] S102, Chamber washing Weigh 2 grams of gallium antimonide powder, and arrange the substrate and powder at specific positions as follows: Figure 1 As shown, the quartz boat is placed in a tube furnace. The vacuum device and argon gas inlet device are turned on, and the inlet flow rate is set to 200 sccm. The inlet flow is continued for 30 seconds. The switching process is repeated five times to ensure that the gas in the chamber is clean enough to avoid contamination of the reaction process by impurities in the air.
[0027] S103, Temperature and Gas Control After the gas washing is completed, the heating time is set to 80 minutes and the temperature is set to 800 degrees Celsius. During the heating process, argon gas is continuously introduced at a flow rate of 200 sccm. After the temperature reaches the set temperature, a certain amount of oxygen is introduced at a flow rate of 20 sccm. After the experiment is completed, the oxygen supply is immediately stopped while the argon gas supply is maintained.
[0028] S104, Chamber Cooling After the experiment, the cooling time was set to 500 minutes. After the cooling time was completed, the vacuum device was turned off and the argon gas supply was stopped. The cavity was opened, the quartz boat was taken out, and the gallium oxide epitaxy was completed.
[0029] The surface image of gallium oxide obtained by scanning electron microscopy (SEM) in Example 1 is shown below. Figure 3 As shown, a relatively dense thin film is grown on the substrate surface, combined with... Figure 7 X-ray diffraction (XRD) analysis revealed that the gallium oxide grown at this temperature was a mixed-phase gallium oxide, with two different crystalline phases of gallium oxide detected. Example 2
[0030] S101, Substrate Pretreatment Before epitaxial growth, the substrate is cleaned. The specific cleaning steps include: immersing the substrate in a solution of concentrated sulfuric acid and hydrogen peroxide in a 4:1 ratio at 100 degrees Celsius, ultrasonically cleaning for 15 minutes to remove surface organic matter and particles, treating with deionized water with a water resistance of 18 megohms for 400 seconds, and then drying it with a nitrogen gun. This removes stains from the substrate surface, which is beneficial for gallium oxide epitaxy. The substrate is sapphire.
[0031] S102, Chamber washing Weigh 2 grams of gallium antimonide powder, and arrange the substrate and powder at specific positions as follows: Figure 1As shown, the quartz boat is placed in a tube furnace. The vacuum device and argon gas inlet device are turned on, and the inlet flow rate is set to 200 sccm. The inlet flow is continued for 30 seconds. The switching process is repeated five times to ensure that the gas in the chamber is clean enough to avoid contamination of the reaction process by impurities in the air.
[0032] S103, Temperature and Gas Control After the gas washing was completed, the heating time was set to 60 minutes and the temperature was set to 760 degrees Celsius. During the heating process, argon gas was continuously introduced at a flow rate of 200 sccm. After the temperature reached the set temperature, a certain amount of oxygen was introduced at a flow rate of 10 sccm. After the experiment was completed, the oxygen introduction was immediately stopped while the argon gas introduction was maintained.
[0033] S104, Chamber Cooling After the experiment, the cooling time was set to 500 minutes. After the cooling time was completed, the vacuum device was turned off and the argon gas supply was stopped. The cavity was opened, the quartz boat was taken out, and the gallium oxide epitaxy was completed.
[0034] The surface image of gallium oxide obtained by scanning electron microscopy (SEM) in Example 2 is shown below. Figure 4 As shown, a relatively dense thin film is also grown on the substrate surface, combined with... Figure 7 X-ray diffraction (XRD) analysis revealed that the gallium oxide grown under these temperature conditions was a mixed-phase gallium oxide, and two different crystalline phases of gallium oxide were detected. Example 3
[0035] S101, Substrate Pretreatment Before epitaxial growth, the substrate is cleaned. The specific cleaning steps include: immersing the substrate in a solution of concentrated sulfuric acid and hydrogen peroxide in a 5:1 ratio at 150 degrees Celsius, ultrasonically cleaning for 10 minutes to remove surface organic matter and particles, treating with deionized water with a water resistance of 18 megohms for 600 seconds, and then drying it with a nitrogen gun. This removes stains from the substrate surface, which is beneficial for gallium oxide epitaxy. The substrate is sapphire.
[0036] S102, Chamber washing Weigh 4 grams of gallium antimonide powder, and arrange the substrate and powder at specific positions as follows: Figure 1 As shown, the quartz boat is placed in a tube furnace. The vacuum device and argon gas inlet device are turned on, and the inlet flow rate is set to 150 sccm. The inlet flow is continued for 30 seconds. The switching process is repeated five times to ensure that the gas in the chamber is clean enough to avoid contamination of the reaction process by impurities in the air.
[0037] S103, Temperature and Gas Control After the gas washing is completed, the heating time is set to 40 minutes and the temperature is set to 720 degrees Celsius. During the heating process, argon gas is continuously introduced at a flow rate of 100 sccm. After the temperature reaches the set temperature, a certain amount of oxygen is introduced at a flow rate of 10 sccm. After the experiment is completed, the oxygen introduction is immediately stopped while the argon gas introduction is maintained.
[0038] S104, Chamber Cooling After the experiment, the cooling time was set to 400 minutes. After the cooling time was completed, the vacuum device was turned off and the argon gas supply was stopped. The cavity was opened, the quartz boat was taken out, and the gallium oxide epitaxy was completed.
[0039] The surface image of gallium oxide obtained by scanning electron microscopy (SEM) in Example 3 is shown below. Figure 5 As shown, a dense thin film was grown on the substrate surface, combining... Figure 7 X-ray diffraction (XRD) analysis revealed that the grown thin film was the desired β-phase gallium oxide film. Comparative Example 1
[0040] S101, Substrate Pretreatment Before epitaxial growth, the substrate is cleaned. The specific cleaning steps include: immersing the substrate in a solution of concentrated sulfuric acid and hydrogen peroxide in a 4:1 ratio at 100 degrees Celsius, ultrasonically cleaning for 15 minutes to remove surface organic matter and particles, treating with deionized water with a water resistance of 18 megohms for 400 seconds, and then drying it with a nitrogen gun. This removes stains from the substrate surface, which is beneficial for gallium oxide epitaxy. The substrate is sapphire.
[0041] S102, Chamber washing Weigh 2 grams of gallium antimonide powder, and arrange the substrate and powder at specific positions as follows: Figure 1 As shown, the quartz boat is placed in a tube furnace. The vacuum device and argon gas inlet device are turned on, and the inlet flow rate is set to 200 sccm. The inlet flow is continued for 30 seconds. The switching process is repeated five times to ensure that the gas in the chamber is clean enough to avoid contamination of the reaction process by impurities in the air.
[0042] S103, Temperature and Gas Control After the gas washing is completed, the heating time is set to 60 minutes and the temperature is set to 680 degrees Celsius. During the heating process, argon gas is continuously introduced at a flow rate of 200 sccm. After the temperature reaches the set temperature, a certain amount of oxygen is introduced at a flow rate of 10 sccm. After the experiment is completed, the oxygen introduction is immediately stopped while the argon gas introduction is maintained.
[0043] S104, Chamber Cooling After the experiment, the cooling time was set to 500 minutes. After the cooling time was completed, the vacuum device was turned off and the argon gas supply was stopped. The cavity was opened, the quartz boat was taken out, and the gallium oxide epitaxy was completed.
[0044] The surface image of the scanning electron microscope (SEM) in Comparative Example 1 is shown below. Figure 6 As shown, it can be seen that after the temperature decreases, no dense gallium oxide film is grown on the substrate surface; combined with Figure 7 The X-ray diffraction (XRD) analysis results show that no diffraction peaks were detected, indicating that no gallium oxide film was grown under these temperature conditions.
[0045] In summary, this invention provides a method for growing gallium oxide thin films using a gallium antimonide metal source, comprising: substrate pretreatment; chamber purging; temperature and gas control; and chamber cooling. In the above gallium oxide growth process, gallium oxide powder or gallium metal particles are not required to participate in the reaction. The selected reaction source is a gallium antimonide metal compound, and gallium oxide thin films can be grown at a temperature of 720 degrees Celsius. Simultaneously, under a low-pressure experimental environment, reaction byproducts and impurities are also discharged from the chamber along with the carrier gas to avoid contamination. As can be seen from the specific embodiments, using a gallium antimonide metal compound to grow gallium oxide achieves gallium oxide growth at a relatively low reaction temperature.
[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0047] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.
Claims
1. A method for growing gallium oxide thin films using a gallium antimonide metal source, characterized in that, Includes the following steps: Gallium antimonide was selected as the gallium metal source, oxygen as the oxygen source, and argon as the carrier gas to grow gallium oxide epitaxial films through low-pressure gas-phase chemical reaction.
2. The method for growing gallium oxide thin films using a gallium antimonide metal source according to claim 1, characterized in that, The temperature of the low-pressure gas-phase chemical reaction is 700-1000℃.
3. The method for growing gallium oxide thin films using a gallium antimonide metal source according to claim 1, characterized in that, The flow rate ratio of oxygen to argon is 1:4 to 1:
100.
4. The method for growing gallium oxide thin films using a gallium antimonide metal source according to claim 1, characterized in that, Oxygen flow rate is 1-100 sccm, and argon flow rate is 50-500 sccm.
5. The method for growing gallium oxide thin films using a gallium antimonide metal source according to claim 4, characterized in that, The oxygen flow rate is 5-50 sccm, and the argon flow rate is 100-200 sccm.
6. A method for growing gallium oxide thin films using a gallium antimonide metal source according to any one of claims 1-5, characterized in that, The method specifically includes the following steps: (1) Use a mixed solution of concentrated sulfuric acid and hydrogen peroxide with a volume ratio of 3:1 to 5:1 and deionized water to clean the substrate and remove surface impurities; (2) Place the substrate and gallium antimonide into a tube furnace, close the furnace chamber and repeatedly evacuate and introduce argon gas five times. The flow rate of the introduced argon gas is 50-300 sccm. (3) Turn on the heating system and continuously introduce argon gas. After heating to the set temperature, introduce oxygen gas. The oxygen gas reacts with gallium antimonide to generate gallium oxide and antimony oxide. (4) After the reaction is complete, stop the oxygen supply, set the cooling program to the room temperature, and the cooling time is 200-600 minutes. Open the chamber and take out the gallium oxide epitaxial film.