Gas recycling MOCVD thin film deposition equipment and process method

Abstract

This invention discloses a gas-recycling MOCVD thin film deposition equipment and process, relating to the field of chemical vapor deposition reaction technology. The equipment includes a reaction chamber, a resistance wire heater, an MO source inlet, a circulation pipeline, a gas pump, an oxygen source inlet, a horizontal surrounding pipeline, a gas baffle plate, a gas equalization plate, a rotating shaft, fan blades, and a substrate. The equipment and process of this invention effectively solve problems such as uneven gas distribution and gas waste in existing thin film deposition devices. Utilizing a gas recycling system not only improves gas utilization but also reduces resource waste during production. Furthermore, the uniform mixing of the gas and the rotation of the shaft result in more uniform thin film deposition, significantly improving the quality and uniformity of the film. This device has significant advantages in applications such as semiconductors, optoelectronic devices, and solar cells, improving production efficiency, reducing costs, and being environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of chemical vapor deposition reaction technology, and in particular to a MOCVD thin film deposition equipment and process method that utilizes gas recycling. Background Technology

[0002] With the development of semiconductor, optoelectronic technology, and new energy fields, thin film materials are being used more and more widely. Chemical vapor deposition (MOCVD) is an important technology widely used in thin film material preparation, semiconductor device manufacturing, and surface coating. The MOCVD process relies on a chemical reaction occurring on the substrate surface using a gaseous reaction source to form the desired thin film or material. Especially in the preparation of metal oxide thin films, the mixing and reaction of the metal oxide source gas (MO source) with the oxygen source gas is a crucial step in thin film deposition.

[0003] However, traditional thin film deposition equipment often employs static gas introduction, which can easily lead to uneven gas distribution, thus affecting the uniformity and quality of the film. Furthermore, current thin film deposition technologies suffer from low gas source utilization efficiency; many devices cannot effectively recover unreacted MO sources, resulting in gas waste, higher material costs, and environmental pollution. Moreover, frequent gas source replacements are often required, further increasing production costs.

[0004] To address the aforementioned issues, some existing technologies attempt to improve gas utilization by employing rotating cavities or gas recirculation systems. However, these technologies still suffer from problems such as insufficient gas mixing, unstable deposited film quality, and low gas utilization efficiency.

[0005] Therefore, there is an urgent need for a new device structure that can achieve efficient gas mixing and uniform deposition, and can recover unreacted gas sources, thereby improving resource utilization, reducing costs, and improving film quality in the thin film deposition process. Summary of the Invention

[0006] To address the aforementioned problems, this invention proposes a gas recycling MOCVD thin film deposition equipment and process, which can solve the problems of gas waste and uneven gas distribution in the prior art, and provide a more efficient and environmentally friendly thin film preparation solution.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a gas recycling MOCVD thin film deposition apparatus, comprising: A resistance wire heater located outside the reaction chamber is used to provide heat to the reaction chamber; The MO source inlet is located on one side of the reaction chamber. The MO source inlet is connected to a circulation pipe. An air pump is installed in the circulation pipe for the recycling of the MO source. The oxygen source inlet is located on the other side of the reaction chamber. The oxygen source inlet includes three vertically distributed inlets, each of which is connected to a horizontally surrounding pipe. The horizontally surrounding pipe is distributed throughout the horizontal cavity between the gas baffle and the gas equalization plate. Oxygen source exhaust holes are evenly distributed on the side wall of the horizontally surrounding pipe for spraying out oxygen source. The rotating shaft located in the middle of the reaction chamber has a hollow structure. The rotating shaft is provided with fan blades and multiple evenly distributed 4-inch substrates around its circumference. MO source exhaust holes are distributed around the rotating shaft and fan blades to eject gas. The lower end of the rotating shaft is connected to the lower end of the circulation pipe, which is used to guide the MO source into the internal channel of the rotating shaft and eject it through the MO source exhaust hole on the rotating shaft; An air baffle plate is placed above the air distribution plate and the horizontal surrounding pipe to prevent the oxygen source from reacting with the MO source prematurely. The gas distribution plate, located below the horizontally surrounding pipe and above the fan blades and substrate, is used to evenly distribute the oxygen source and ensure that the gas is fully mixed in the reaction chamber.

[0008] Furthermore, the MO source inlet and the oxygen source inlet are located on the left and right sides of the top of the device, respectively.

[0009] Furthermore, an exhaust outlet is provided at the bottom of the reaction chamber to discharge unreacted gases.

[0010] Furthermore, the multi-layered, uniformly distributed 4-inch substrates are located below the fan blades, and ceramic spacers with flow channels are provided between adjacent substrates. The surface of the ceramic spacers is coated with an anti-oxidation coating.

[0011] Furthermore, the MO source exhaust holes are spirally distributed along the surface of the rotating shaft.

[0012] Secondly, the present invention also provides an MOCVD process method, based on the MOCVD thin film deposition equipment with gas recycling as described in any of the above claims, and comprising the following steps: The resistance wire heater is activated to provide heat to the reaction chamber; the MO source enters the rotating shaft channel from the MO source inlet and is ejected from the MO source exhaust port below the gas equalization plate; the oxygen source enters the horizontal circulating pipe from the oxygen source inlet and is ejected from the oxygen source exhaust port above the horizontal circulating pipe, and then is evenly ejected through the gas equalization plate; the two gases mix and react under the rotation of the fan blades and are deposited on the substrate to generate a uniform thin film; the remaining unreacted MO source accumulates at the bottom of the circulation pipe and is returned to the MO source inlet by the action of the air pump, realizing the recycling of the MO source; the unreacted gas is discharged to the external treatment system or recovery system through the exhaust outlet.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Improve gas utilization rate By employing a gas recycling system, unreacted MO source material can accumulate at the bottom of the pipeline and be redirected to the MO source inlet by a gas pump, thus reusing the MO source. This not only reduces gas waste but also lowers production costs and improves gas utilization efficiency.

[0014] 2. Enhance gas mixing uniformity The internal rotating shaft and fan blade structure effectively promote the mixing of the MO source and oxygen source, forming a uniform airflow above the substrate. The combined design of the gas distribution plate and gas baffle plate ensures uniform gas distribution within the reaction zone, avoiding film quality instability caused by uneven airflow.

[0015] 3. Improve the uniformity and quality of thin film deposition. The rotating shaft drives the substrate to rotate, enhancing the gas reaction and deposition effect on the substrate. Due to the thorough mixing and uniform distribution of the gas, the thickness and quality of the film are effectively controlled, resulting in films with higher uniformity and consistency, meeting the requirements of high-precision deposition.

[0016] 4. Cost savings and environmental protection This device significantly reduces gas consumption and waste by recycling unreacted MO source gas, thereby minimizing environmental pollution and contributing to a more environmentally friendly production process. Furthermore, the device's efficient gas utilization reduces reliance on fresh MO sources, further lowering production costs.

[0017] 5. Improve production efficiency The thorough mixing and uniform ejection of gases enhance the reaction process, shortens film deposition time, and improves overall production efficiency. Simultaneously, the gas recovery system ensures continuous gas supply, reducing reliance on external gas sources and further improving production stability and efficiency.

[0018] In summary, the gas recycling MOCVD thin film deposition equipment proposed in this invention can improve production efficiency and reduce costs while ensuring film quality, and has broad application prospects. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1This is a cross-sectional view of a gas recycling MOCVD thin film deposition apparatus provided in an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Reaction chamber; 2. Resistance wire heater; 3. MO source inlet; 4. Circulation pipeline; 5. Air pump; 6. Oxygen source inlet; 7. Horizontal surrounding pipeline; 8. Gas baffle plate; 9. Gas equalization plate; 10. Rotating shaft; 11. Fan blade; 12. Substrate; 13. Exhaust gas outlet; 14. MO source exhaust port. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] This invention provides a gas recycling MOCVD thin film deposition apparatus, such as... Figure 1 As shown, it mainly consists of components such as reaction chamber 1, resistance wire heater 2, MO source inlet 3, circulation pipe 4, gas pump 5, oxygen source inlet 6, horizontal surrounding pipe 7, gas baffle plate 8, gas equalization plate 9, rotating shaft 10, fan blade 11 and substrate 12. It can deposit a uniform thin film on substrate 12 by precisely controlling the gas flow rate and mixing effect.

[0024] 1. Resistance wire heater: The resistance wire heater 2, located outside the reaction chamber 1, heats the outer shell of the reaction chamber and its internal reaction chamber by heating current, ensuring that the required temperature (e.g., 500°C to 800°C) is reached in the reaction zone to promote the deposition process of the thin film.

[0025] 2. MO source inlet and gas circulation pipeline: MO source inlet 3 is located on the left side of the device. MO source gas enters the connected circulation pipe 4 through MO source inlet 3. A gas pump 5 is installed inside the circulation pipe 4 to promote the recirculation of the MO source gas. Unreacted MO source gas accumulates at the bottom of the circulation pipe 4 and is redirected back to the MO source inlet by the gas pump 5. The gas pump 5 can be a low-noise, high-efficiency type to ensure the stability of gas circulation within the circulation pipe.

[0026] 3. Oxygen source import: Oxygen source inlet 6 is located on the right side of the device, with three oxygen source inlets perpendicular to the radial direction of the reaction chamber. These inlets are connected to horizontal surrounding pipes 7, which introduce oxygen source gas into the reaction chamber. The oxygen source gas is evenly ejected through oxygen source exhaust holes in the horizontal surrounding pipes 7. Multiple oxygen source exhaust holes are evenly distributed on both sides of the horizontal surrounding pipes 7 to ensure that the oxygen source gas is evenly distributed in the reaction chamber.

[0027] 4. Shaft, fan blades, and substrate structure: The rotating shaft 10, located in the center of the device, is a hollow structure with fan blades 11 and five 4-inch substrates 12 arranged circumferentially on its exterior. The fan blades 11 are positioned above the substrates 12. A motor drives the rotating shaft 10 to rotate, which in turn rotates the fan blades 11 and the substrates 12. Multiple MO source exhaust ports 14 are arranged around the rotating shaft 10 and fan blades 11 to eject MO source gas. The rotation of the rotating shaft 10 causes the substrates 12 to rotate synchronously, thereby promoting the mixing and reaction of the MO source and oxygen source gas.

[0028] The reaction zone above the substrate 12 is a critical area for thin film deposition. The rotation of the shaft 10 not only improves the gas mixing efficiency but also ensures uniform gas deposition on the substrate 12, preventing thin film inhomogeneity.

[0029] 5. Air barrier and air distribution plate: The gas equalization plate 9 is located above the fan blade 11 and the substrate 12 to ensure that the oxygen source gas is sprayed out evenly and that the gas distribution is uniform. The gas barrier plate 8 is located above the gas equalization plate 9 and the horizontal surrounding pipe 7, and serves to prevent the MO source and oxygen source gas from reacting prematurely, ensuring that the two gases react fully within the predetermined reaction zone, thereby obtaining a high-quality thin film.

[0030] 6. Exhaust gas outlet: The device has an exhaust outlet 13 at the bottom for discharging unreacted gases. The exhaust gases are discharged through pipes to an external treatment or recycling system to reduce environmental pollution.

[0031] The present invention also provides an MOCVD process method suitable for compound semiconductor growth, based on the MOCVD thin film deposition equipment with gas recycling as described in any of the above claims, and includes the following steps: The resistance wire heater 2 is activated to provide heat to the reaction chamber; the MO source enters the internal channel of the rotating shaft 10 from the MO source inlet 3 and is ejected from the MO source exhaust port below the gas equalization plate 9; the oxygen source enters the horizontal surrounding pipe 7 from the oxygen source inlet 6 and is ejected from the oxygen source exhaust port above the horizontal surrounding pipe 7, and is then uniformly ejected through the gas equalization plate 9; the two gases mix and react under the rotation of the fan blade 11 and are deposited on the substrate 12 to generate a uniform thin film; the remaining unreacted MO source accumulates at the bottom of the circulation pipe 4 and returns to the MO source inlet 3 through the action of the air pump 5, realizing the recycling of the MO source; the unreacted gas is discharged to the external treatment system or recycling system through the exhaust outlet 13.

[0032] Working principle: 1. Gas introduction and circulation: MO source gas enters the reaction device from the left MO source inlet 3. After entering, it passes through the circulation pipe 4 and the gas pump 5, then enters the internal channel of the rotating shaft 10 through the lower end of the rotating shaft 10, and is ejected from the MO source exhaust holes 14 around the rotating shaft 10. The rotation of the rotating shaft 10 causes the MO source gas to be evenly distributed in the reaction zone.

[0033] Oxygen source gas enters the device from the oxygen source inlet 6 on the right side. The oxygen source gas enters the horizontally circulating pipe 7 through three vertical inlets and is evenly sprayed out through the oxygen source exhaust holes on both sides of the pipe to ensure the uniform distribution of oxygen source in the reaction zone.

[0034] 2. Reaction process: Under the rotation of shaft 10, the MO source gas and oxygen source gas mix in the reaction chamber and form a metal oxide thin film after the reaction. The rotation of fan blade 11 ensures more thorough mixing of the gas in the reaction zone, guaranteeing the uniformity and quality of the thin film.

[0035] The thin film generated by the reaction of oxygen source gas and MO source gas is uniformly deposited on substrate 12, eventually forming the desired metal oxide thin film.

[0036] 3. Gas recovery and reuse: The exhaust outlet 13 at the bottom of the device is connected to an external treatment or recovery system via a pipeline to collect unreacted MO source gas. This gas is then pumped back into the MO source inlet 3 via the circulation pipeline 4 using the gas pump 5 for gas recycling. This process reduces gas waste while lowering gas consumption and production costs.

[0037] 4. Film quality control: Due to the uniform distribution and thorough mixing of the gas, the film deposition process is more uniform, ensuring the thickness, quality, and uniformity of the film. The rotation of the shaft 10 increases the contact time between the substrate 12 and the gas, contributing to the high-quality formation of the film.

[0038] Implementation results:

[0039] Through the aforementioned structure and working principle, this embodiment effectively solves the problems of uneven gas distribution and gas waste in existing thin film deposition apparatuses. Utilizing a gas recycling system not only improves gas utilization but also reduces resource waste during production. Furthermore, the uniform mixing of the gas and the rotation of the shaft result in more uniform thin film deposition, significantly improving the quality and uniformity of the film. This device offers significant advantages in applications such as semiconductors, optoelectronic devices, and solar cells, improving production efficiency, reducing costs, and being environmentally friendly.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas-recycling MOCVD thin film deposition apparatus, characterized in that, include: A resistance wire heater located outside the reaction chamber is used to provide heat to the reaction chamber; The MO source inlet is located on one side of the reaction chamber. The MO source inlet is connected to a circulation pipe. An air pump is installed in the circulation pipe for the recycling of the MO source. The oxygen source inlet is located on the other side of the reaction chamber. The oxygen source inlet includes three vertically distributed inlets, each of which is connected to a horizontally surrounding pipe. The horizontally surrounding pipe is distributed throughout the horizontal cavity between the gas baffle and the gas equalization plate. Oxygen source exhaust holes are evenly distributed on the side wall of the horizontally surrounding pipe for spraying out oxygen source. The rotating shaft located in the middle of the reaction chamber has a hollow structure. The rotating shaft is provided with fan blades and multiple evenly distributed 4-inch substrates around its circumference. MO source exhaust holes are distributed around the rotating shaft and fan blades to eject gas. The lower end of the rotating shaft is connected to the lower end of the circulation pipe, which is used to guide the MO source into the internal channel of the rotating shaft and eject it through the MO source exhaust hole on the rotating shaft; An air baffle plate is placed above the air distribution plate and the horizontal surrounding pipe to prevent the oxygen source from reacting with the MO source prematurely. The gas distribution plate, located below the horizontally surrounding pipe and above the fan blades and substrate, is used to evenly distribute the oxygen source and ensure that the gas is fully mixed in the reaction chamber.

2. The MOCVD thin film deposition equipment with gas recycling according to claim 1, characterized in that, The MO source inlet and the oxygen source inlet are located on the left and right sides of the top of the device, respectively.

3. The MOCVD thin film deposition equipment with gas recycling according to claim 1, characterized in that, The bottom of the reaction chamber is provided with an exhaust gas outlet for discharging unreacted gases.

4. The MOCVD thin film deposition equipment with gas recycling according to claim 1, characterized in that, The multi-layered, evenly distributed 4-inch substrates are located below the fan blades, and ceramic spacers with flow channels are provided between adjacent substrates. The surface of the ceramic spacers is coated with an anti-oxidation coating.

5. The MOCVD thin film deposition equipment with gas recycling according to claim 1, characterized in that, The MO source exhaust holes are spirally distributed along the surface of the rotating shaft.

6. An MOCVD process method, characterized in that, The MOCVD thin film deposition apparatus based on any one of claims 1-5, and comprising the following steps: The resistance wire heater is activated to provide heat to the reaction chamber; the MO source enters the rotating shaft channel from the MO source inlet and is ejected from the MO source exhaust port below the gas equalization plate; the oxygen source enters the horizontal circulating pipe from the oxygen source inlet and is ejected from the oxygen source exhaust port above the horizontal circulating pipe, and then is evenly ejected through the gas equalization plate; the two gases mix and react under the rotation of the fan blades and are deposited on the substrate to generate a uniform thin film; the remaining unreacted MO source accumulates at the bottom of the circulation pipe and is returned to the MO source inlet by the action of the air pump, realizing the recycling of the MO source; the unreacted gas is discharged to the external treatment system or recovery system through the exhaust outlet.

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