MOCVD (Metal Organic Chemical Vapor Deposition) reactor for normal-pressure growth and film growth method

Abstract

The invention relates to an MOCVD (Metal Organic Chemical Vapor Deposition) reactor for normal-pressure growth and a film growth method, belongs to the technical field of semiconductor material preparation, and solves the problems that a film formed by a horizontal air inlet MOCVD reactor in the prior art is thick in front and thin in rear, poor in uniformity and locally accumulated. The device comprises a reaction chamber, a gas inlet assembly and a reaction assembly, the reaction assembly is arranged in the center of the reaction chamber, and the gas inlet assembly is arranged on the first side of the reaction assembly and used for providing reaction gas for the reaction assembly; reaction gas enters the reaction assembly in a layered mode, and the reaction gas comprises upper-layer ammonia gas, a middle-layer MO source, carrier gas and lower-layer ammonia gas. The uniformity of the formed film can be improved, and local accumulation is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material preparation technology, and in particular to an MOCVD reactor and thin film growth method under normal pressure. Background Technology

[0002] In the MOVCD (Metal-Organic Chemical Vapor Deposition) epitaxial growth process, existing atmospheric pressure MOCVD large-size substrates of 8 inches and above have the problem of different growth rates between the center and the edge, and the utilization rate of MO (metal-organic compound) source is low, resulting in films that are thicker at the front and thinner at the back, with poor uniformity and local accumulation. Summary of the Invention

[0003] Based on the above analysis, the present invention aims to provide an atmospheric pressure MOCVD reactor and a thin film growth method to solve one of the problems in the prior art of horizontally inlet MOCVD reactors, such as thin films at the front and thin films at the back, poor uniformity, and local accumulation.

[0004] An MOCVD reactor for atmospheric pressure growth is provided, comprising a reaction chamber, an inlet assembly, and a reaction assembly; The reaction assembly is disposed in the reaction chamber, and the air intake assembly is disposed on the first side of the reaction assembly for providing reaction gas to the reaction assembly; the reaction chamber is provided with an exhaust pipe, which is disposed on the second side of the reaction assembly, with the first side and the second side opposite to each other.

[0005] Furthermore, the air intake assembly includes a carrier gas pipe through which the reaction gas enters the reaction assembly.

[0006] Furthermore, it also includes a nozzle, which is connected to the carrier gas pipe.

[0007] Furthermore, the exhaust pipe has its opening facing downwards; the exhaust pipe is an inverted conical structure, and it is used to discharge the waste gas generated by the reaction assembly.

[0008] Furthermore, it also includes a rotating component; the reaction component includes a substrate, the rotating component is disposed at the lower part of the substrate, and the substrate rotates with the rotating component.

[0009] Furthermore, the rotating assembly also includes a rotating magnetic fluid disposed on the exterior of the rotating assembly.

[0010] Furthermore, the rotating assembly includes a gear set and a carrier disk; the carrier disk is used to fix the tray and the substrate, and the gear set is used to adjust the size of the carrier disk.

[0011] Furthermore, it also includes a heating component disposed inside the rotating component; the heating component is radially distributed along the substrate.

[0012] Furthermore, the heating component is an independent temperature-controlled electrode.

[0013] Another aspect of the present invention provides a thin film growth method using the aforementioned atmospheric pressure MOCVD reactor, specifically comprising the following steps: Step 1: Introduce MO source gas, carrier gas, and ammonia according to the set ratio; Step 2: Ammonia and MO source gas react in the reaction unit, and exhaust gas is discharged.

[0014] Furthermore, the reaction gases enter the reaction assembly in layers, including an upper layer of ammonia, a middle layer of MO source and carrier gas, and a lower layer of ammonia.

[0015] Furthermore, the carrier gas pipe includes a first carrier gas pipe, a second carrier gas pipe, and a third carrier gas pipe; the first carrier gas pipe is used to transport upper-layer ammonia; the second carrier gas pipe is used to transport middle-layer MO source; and the third carrier gas pipe is used to transport lower-layer ammonia. The first carrier gas pipe, the second carrier gas pipe, and the third carrier gas pipe each include an inlet end and an outlet end. The inlet end is connected to the nozzle, and the outlet end is connected to the reaction assembly.

[0016] Furthermore, the air intake assembly also includes a water tank, and the first air carrier pipe, the second air carrier pipe and the third air carrier pipe also include an intermediate section, which is horizontally stacked in the water tank; The water box contains cooling water, which is used to cool the intermediate section.

[0017] Furthermore, the jet end is the horizontal extension end of the intermediate section.

[0018] Furthermore, the carrier plate includes a support frame and a telescopic rod; the support frame is sleeved outside the rotating shaft of the rotating assembly and has a plurality of protruding rods with T-shaped grooves radiating outward in the radial direction; the T-shaped grooves are arranged along the length direction of the protruding rods; One end of the telescopic rod is slidably disposed in the T-shaped groove, and the other end is used to hold the tray and the substrate.

[0019] Furthermore, the gear set includes a gear disk and a drive gear, the drive gear meshing with the gear disk, and the rotation of the drive gear can drive the gear disk to rotate; The gear disk is provided with a plurality of arc-shaped through grooves, which extend obliquely outward from the central axis of the gear disk; the arc-shaped through grooves include a first end and a second end; A pin is fixed to the telescopic part, and the pin is slidably disposed in the arc-shaped through groove; when the pin is located at the first end, the telescopic rod is the shortest; when the pin is located at the second end, the telescopic rod is the longest.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. In this invention, the reaction assembly is located at the center of the reaction chamber, the gas inlet assembly is located on the first side of the reaction assembly, and the exhaust pipe is located on the second side of the reaction assembly, with the first and second sides opposite to each other. The reaction gas enters from one side of the reaction chamber, and the exhaust gas exits from the other side. The reaction gas can react fully on the substrate, improving the utilization rate of MO gas and reducing the phenomenon of reactant inhomogeneity.

[0021] 2. The carrier gas tubes are horizontally stacked, shortening the distance between the nozzle and the substrate. The cooling water in the water tank is concentrated to cool the carrier gas tubes. Compared with the existing technology that uses cooling water pipes for cooling, this method occupies less space, is more compact, has a better cooling effect, and improves the lifespan of the carrier gas tubes. At the same time, after the reactant gases in the carrier gas tubes are cooled, it prevents concentrated reactions between different gases at the gas inlet of the reaction component, which would cause the thin film to grow concentrated at the gas inlet, improving the controllability and safety of the reaction, and enhancing the stability of the system.

[0022] 3. The exhaust pipe is positioned on the opposite side of the intake assembly, which is conducive to the full reaction of the gas in the reaction assembly. The exhaust pipe has an inverted conical structure, which creates an acceleration effect at the outlet end, allowing the gas after the reaction to be discharged quickly. This avoids the formation of stagnant areas in the reaction chamber or exhaust port, reduces the ineffective consumption of unreacted gas, reduces the residence time of gas in the exhaust channel, reduces the deposition of by-products, and reduces the contamination of epitaxial wafers by by-products, thus reducing the risk of blockage.

[0023] 4. The rotating component drives the substrate to rotate, forming a spiral airflow when the substrate and gas channel rotate, which improves the uniformity of the lateral distribution of the covered area, effectively improves the film deposition rate, and avoids local accumulation.

[0024] 5. The heating components are set at different radii to form a gradient heating, which avoids the problem of uneven film deposition thickness and unbalanced stress distribution caused by the rapid heat dissipation at the edges and the accumulation of heat in the center of the substrate during the heating process. This improves the uniformity of film growth.

[0025] 6. The reaction assembly is filled with three layers of gas (upper layer NH4, lower layer NH4, middle layer MO and carrier gas) for reaction. The gas flow is horizontal along the gas inlet, passes through the reaction assembly and then flows into the exhaust pipe. After a certain distance of reaction, the density of the lower layer ammonia decreases and the upper layer ammonia compensates for it. This prevents the phenomenon of uneven film thickness that often occurs during the deposition of thin films with horizontal gas inlet, such as the film being thicker at the front and thinner at the back. This achieves the technical effect of improving the uniformity of material growth on the substrate surface.

[0026] 7. In this invention, the three nozzles are connected to the three carrier gas pipes respectively, which makes it easy for a single nozzle to independently control the flow rate and pressure of the reaction gas in the carrier gas pipe, realize multi-zone gas control, and effectively control the layer gas density in each zone, so that the upper layer ammonia, the middle layer MO source and the carrier gas, and the lower layer ammonia can all enter the gas in the required proportion, thereby improving the utilization rate and deposition rate of the MO source.

[0027] 8. In this invention, the gas intake is controlled by partitioning, which effectively controls the gas intake density of each layer and increases the MO deposition rate; the horizontal stacking of water carrier pipes reduces the distance between the nozzle and the substrate by 34% and shortens the reaction distance by 75%; the water box centrally cools the gas carrier pipes, the spiral airflow generated by the substrate rotation dynamically compensates for the gas deposition on the substrate, independent partitioned temperature control, and the coupling effect of the flow field and temperature field achieve a lateral average distribution of the covered area, effectively improving the uniformity of thin film deposition and achieving a thin film non-uniformity of <2%.

[0028] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0029] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 This is a schematic diagram of the structure of an atmospheric pressure MOCVD reactor; Figure 2 This is a schematic diagram of the nozzle structure; Figure 3 This is a schematic diagram of the air intake state of the cross-section of the reaction space; Figure 4 This is a top view of the gear set and the carrier disk; Figure 5 This is a bottom view of the gear set and carrier disk.

[0030] Figure label: 1-Reaction chamber; 11-Exhaust pipe; 2-Intake assembly; 21-Gas chamber; 211-First gas chamber; 212-Second gas chamber; 213-Third gas chamber; 22-Carrier gas pipe; 221-First carrier gas pipe; 222-Second carrier gas pipe; 223-Third carrier gas pipe; 23-Nozzle; 231-First nozzle; 232-Second nozzle; 233-Third nozzle; 24-Water box; 3-Reaction assembly; 31-First 32-Second plate; 33-Substrate; 4-Rotating assembly; 41-Tray; 42-Rotating cylinder; 43-Rotating magnetic fluid; 44-Gear set; 441-Drive gear; 442-Gear disk; 4421-Arc-shaped through slot; 45-Carrier disk; 451-Support frame; 4511-Extending rod; 4512-Protrusion; 452-Telescopic rod; 4521-Arc-shaped part; 4522-Telescopic part; 5-Independent temperature control electrode. Detailed Implementation

[0031] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0032] Example 1 A specific embodiment of the present invention, such as Figure 1 As shown, an atmospheric pressure MOCVD reactor is disclosed, including a reaction chamber 1, an air inlet assembly 2, and a reaction assembly 3.

[0033] The reaction assembly 3 is located at the center of the reaction chamber 1, and the gas inlet assembly 2 is located on the first side of the reaction assembly 3 to provide reaction gas to the reaction assembly 3.

[0034] The reaction chamber 1 is equipped with an exhaust pipe 11, which is located on the second side of the reaction assembly 3, with the first side and the second side opposite to each other.

[0035] Specifically, the reaction gases enter the reaction component 3 in layers, including upper ammonia, middle MO source and carrier gas, and lower ammonia.

[0036] To address the issues of uneven film thickness, poor uniformity, and localized accumulation in horizontally inlet MOCVD reactors compared to existing technologies, this embodiment sets the reaction assembly 3 at the center of the reaction chamber 1, the air inlet assembly 2 on one side of the reaction assembly 3, and the exhaust pipe 11 on the opposite side of the air inlet assembly 2. The reaction assembly 3 is circulated with three layers of air (upper layer NH4, lower layer NH4, middle layer MO, and carrier gas) for reaction. The airflow flows horizontally along the air inlet through the reaction assembly 3 and then into the exhaust pipe 11. After a certain reaction distance, the density of the lower layer ammonia decreases, and the upper layer ammonia compensates, preventing the uneven film thickness often seen in horizontally inlet MOCVD reactors. This achieves the technical effect of improving the uniformity of material growth on the substrate 33 surface.

[0037] In this embodiment, the reaction gas is introduced in three layers: upper ammonia, middle MO source, and lower ammonia. The lower layer preferentially mixes and reacts with the middle layer. After reacting for a certain distance, the density of the lower ammonia decreases, and the upper ammonia compensates for this. This prevents the phenomenon of uneven film thickness, which often occurs in the horizontal gas introduction process, where the film is thicker at the front and thinner at the back. This improves the uniformity of material growth on the substrate 33 surface and reduces the phenomenon of pre-reaction of the reaction gas when the premixed gas is introduced horizontally in the prior art.

[0038] Specifically, the reaction chamber 1 includes a shell, which is a cylindrical structure. The reaction assembly 3 is located at the center of the shell, and the air intake assembly 2 is located on the first side of the reaction assembly 3, extending partially outside the shell. The air intake method is horizontal. The exhaust pipe 11 is located on the second side of the reaction assembly 3, opposite to the first side. One end of the exhaust pipe 11 is connected to the reaction assembly 3, and the other end extends downward from the bottom of the shell to discharge the gases produced in the reaction.

[0039] For example, the exhaust pipe 11 is an inverted conical structure. The inverted conical structure creates an acceleration effect at the outlet end of the exhaust pipe 11, which can quickly discharge the reacted gas, avoid the formation of a stagnation zone in the reaction chamber or exhaust port, reduce the ineffective consumption of unreacted gas, reduce the residence time of gas in the exhaust channel, reduce the deposition of by-products and the contamination of epitaxial wafers caused by by-product deposition, and reduce the risk of blockage.

[0040] Specifically, the air intake assembly 2 includes a nozzle 23, an air chamber 21, and a carrier air pipe 22.

[0041] For example, the gas chamber 21 has a rectangular structure. One end of the gas chamber 21 is connected to the nozzle 23, and the other end is connected to the carrier gas pipe 22. The gas chamber 21 includes a first gas chamber 211, a second gas chamber 212, and a third gas chamber 213. In order to make the first gas chamber 211, the second gas chamber 212, and the third gas chamber 213 have the same volume, the bottom of the second gas chamber 212 is higher than the bottom of the third gas chamber 213, and lower than the bottom of the first gas chamber 211.

[0042] The carrier gas pipe 22 includes a first carrier gas pipe 221, a second carrier gas pipe 222, and a third carrier gas pipe 223. The first carrier gas pipe 221 is used to introduce ammonia gas, the second carrier gas pipe 222 is used to introduce the MO source and the carrier gas, and the third carrier gas pipe 223 is used to introduce ammonia gas. Exemplarily, the first carrier gas pipe 221, the second carrier gas pipe 222, and the third carrier gas pipe 223 are all made of stainless steel, each has a separate flow controller (not shown), and each flow controller is connected to a controller to control the flow rate of the carrier gas and the reactant gas as needed.

[0043] Ammonia, MO source and carrier gas enter through their respective carrier gas pipes 22, which facilitates independent control of gas flow and pressure, reduces pre-reaction of gas before entering reaction chamber 1 and improves gas utilization.

[0044] In the growth of MO materials, the MO source must be mixed with ammonia gas to achieve material deposition; neither can be omitted. However, if the gases are completely mixed too early before entering the reaction zone, it will trigger a violent gas-phase pre-reaction, which will not only reduce the utilization efficiency of the raw materials but also affect the crystal quality of the final material.

[0045] In the horizontal gas inlet method, since the lower gas layer is closer to the high-temperature region, ammonia will preferentially react with the MO source, causing the ammonia concentration to gradually decrease downstream along the gas flow direction, resulting in uneven growth on the substrate 33 surface. To reduce the growth non-uniformity of the horizontal gas inlet, this embodiment sets up a three-layer gas inlet: an upper layer of ammonia, a middle layer of MO source and carrier gas, and a lower layer of ammonia, forming a sandwich effect for the MO source. During the reaction process, the lower layer of ammonia is consumed first, and the upper layer of ammonia then compensates for the amount of ammonia reduced by the reaction in the lower layer, so that the entire substrate 33 surface obtains uniform material growth and improves the utilization rate of the MO source.

[0046] like Figure 2 As shown, the first gas carrier pipe 221, the second gas carrier pipe 222, and the third gas carrier pipe 223 each include an inlet end, an outlet end, and an intermediate section. The inlet end is connected to the gas chamber 21, the outlet end is connected to the reaction chamber 1, and the intermediate section is horizontally stacked. During gas intake, the gas carrier pipe 22 intakes gas from the corresponding gas chamber 21 through the inlet end. The gas is then transported in the intermediate section to the outlet end and output to the reaction assembly 3, reducing gas diffusion leakage or turbulent flow, and ensuring that all gas passing through the gas chamber 21 is directed into the reaction assembly 3, reducing material waste.

[0047] The jetting ends of the first carrier gas pipe 221, the second carrier gas pipe 222, and the third carrier gas pipe 223 are horizontal extensions of the middle section. The first carrier gas pipe 221, the second carrier gas pipe 222, and the third carrier gas pipe 223 extend horizontally into the reaction assembly 3 to jet gas.

[0048] Specifically, the jet end of the first carrier air pipe 221 is located in the upper layer, the jet end of the second carrier air pipe 222 is located in the middle layer, and the jet end of the third carrier air pipe 223 is located in the lower layer.

[0049] The inlet end of the first air carrier pipe 221 is connected to the bottom of the first air chamber 211, the inlet end of the second air carrier pipe 222 is connected to the bottom of the second air chamber 212, and the inlet end of the third air carrier pipe 223 is connected to the bottom of the third air chamber 213.

[0050] For example, the bottom of the first air chamber 211, the second air chamber 212 and the third air chamber 213 are provided with vent holes, which are respectively connected to the first air carrier pipe 221, the second air carrier pipe 222 and the third air carrier pipe 223.

[0051] For example, such as Figure 3 As shown, the jet end of the second carrier gas pipe 222 is higher than the jet end of the third carrier gas pipe 223 and lower than the jet end of the first carrier gas pipe 221. This arrangement forms an upper layer of ammonia, a middle layer of MO source and carrier gas, and a lower layer of ammonia when gas is introduced into the reaction assembly 3. This avoids the "dead zone" caused by local over-reaction and local non-reaction due to gas concentration in a certain area of ​​the reaction assembly 3. Both the upper and lower layer ammonia can react with the middle layer MO source, achieving multi-zone gas control and effectively controlling the layer gas density in each zone. This ensures that the upper layer ammonia, the middle layer MO source and carrier gas, and the lower layer ammonia can all be introduced in the required proportions, thereby improving the utilization rate and deposition rate of the MO source.

[0052] The distance between the jet end of the first gas carrier pipe 221, the second gas carrier pipe 222, and the third gas carrier pipe 223 and the substrate 33 decreases sequentially.

[0053] MO deposition time is proportional to the reaction space height; the greater the reaction space height, the longer the deposition time.

[0054] Therefore, the deposition times of the first carrier gas pipe 221, the second carrier gas pipe 222, and the third carrier gas pipe 223 are shortened sequentially. The ammonia in the first carrier gas pipe 221 enters the reaction assembly 3 last. At this time, the ammonia in the third carrier gas pipe 223 has reacted with the MO in the second carrier gas pipe 222 for a period of time. The ammonia concentration downstream along the gas flow direction gradually decreases, and it is necessary to replenish ammonia from the upper layer to compensate for the amount of ammonia reduced by the reaction in the downstream area. At this time, the ammonia in the first carrier gas pipe 221 reacts with the MO in the second carrier gas pipe 222, so that the position of the substrate 33 away from the jet end of the carrier gas pipe 22 can also react, ensuring that the entire surface of the substrate 33 obtains uniform material growth, further improving the MO utilization rate and improving the uniformity of the formed film.

[0055] The nozzle 23 is located on the outside of the gas chamber 21, and the gas enters the gas chamber 21 through the nozzle 23.

[0056] Nozzle 23 includes a first nozzle 231, a second nozzle 232, and a third nozzle 233, which correspond to the gas output of different gas chambers 21. Specifically, the first nozzle 231 is connected to the first gas chamber 211, the second nozzle 232 is connected to the second gas chamber 212, and the third nozzle 233 is connected to the third gas chamber 213.

[0057] Furthermore, the air intake assembly 2 also includes a water tank 24. One end of the water tank 24 is connected to the air chamber 21, and the other end is connected to the reaction assembly 3. Exemplarily, the water tank 24 is made of stainless steel.

[0058] The water tank 24 has an inner cavity that houses the carrier gas pipe 22. The inner cavity is filled with cooling water, which centrally cools the carrier gas pipe 22 and the gas within it, thus extending the lifespan of the carrier gas pipe 22. Compared to conventional cooling methods using cooling water pipes outside the reaction chamber, this embodiment employs a water tank 24 for centralized cooling, resulting in a smaller footprint, a more compact design, and better cooling performance. During cooling, each gas is transported through its own independent carrier gas pipe 22, reducing the risk of pre-reactions between different gases at the inlet of the reaction component 3, enhancing the controllability and safety of the reaction, and improving system stability.

[0059] To address the issue of poor growth uniformity in substrates with dimensions greater than or equal to 8 inches, this embodiment directly connects the nozzle 23 to the gas chamber 21. The first gas carrier pipe 221, the second gas carrier pipe 222, and the third gas carrier pipe 223 are horizontally stacked from the gas chamber 21 to the middle section entering the reaction assembly 3, and extend horizontally to the reaction assembly 3 before being sprayed. The first gas carrier pipe 221, the second gas carrier pipe 222, and the third gas carrier pipe 223 have a horizontal air intake layout, with the air inlet located on one side of the reaction chamber 1. The reaction gas enters the reaction assembly 3 through the horizontally arranged gas carrier pipe 22 and is sprayed horizontally. Compared to the prior art where the gas carrier pipe 22 extends vertically into the reaction assembly before being sprayed, this embodiment reduces the vertical distance between the substrate 33 and the nozzle 23, shortening the vertical travel of the reaction gas. At the same flow rate, the gas velocity at the spray end of the gas carrier pipe 22 is higher, and the gas travel is increased. The spray end of the substrate 33, which is far from the gas carrier pipe 22, can also receive sufficient growth source, improving the growth uniformity of substrates 33 with dimensions greater than or equal to 8 inches. Furthermore, the horizontal sections of the first carrier gas pipe 221, the second carrier gas pipe 222, and the third carrier gas pipe 223 are stacked in the water box 24 for water cooling, which reduces the temperature of the reaction gas in the carrier gas pipe 22, reduces the risk of blockage of the jet end entering the reaction component 3 due to particles generated by the pre-reaction, and improves the utilization rate of the MO source.

[0060] The reaction assembly 3 is located at the center of the reaction chamber 1, with one end connected to the gas inlet assembly 2 and the other end connected to the exhaust pipe 11. The reaction assembly 3 includes a first plate 31, a second plate 32, and a substrate 33 disposed on the second plate 32. The space between the first plate 31 and the second plate 32 is used for gaseous reactions. The initial upper ammonia, middle MO, and lower ammonia enter from one side through their respective carrier gas pipes 22, and the reacted gases are discharged from the other side.

[0061] In this embodiment, the space between the first plate 31 and the second plate 32 has a long cross-section, and the gas flow direction is parallel to the substrate 33.

[0062] Compared to existing technologies that directly introduce premixed gas via horizontal inlet, this embodiment introduces gas in a layered manner when the carrier gas pipe 22 enters the reaction chamber 1. The middle layer is MO gas, while the upper and lower layers are ammonia gas, achieving multi-zone gas control and effectively controlling the gas density at each layer. Since the compound deposition rate is related to the height in the reaction space, the upper and lower layers are ammonia gas, while the middle layer is MO gas. The lower layer preferentially mixes and reacts with the middle layer. After a certain reaction distance, the ammonia density in the lower layer decreases, and the upper layer compensates, promoting good material growth even at locations far from the gas inlet. By adjusting the interlayer spacing, implementing layered gas introduction, and horizontally stacking the carrier gas pipe 22 within the water box 24, the utilization rate of the MO source is improved, effectively shortening the reaction time for large-size substrates (8 inches and above) and improving growth uniformity.

[0063] The horizontal air intake enters from one end of the reaction component 3 and exits from the other end. In order to further improve the phenomenon that the film deposition process of horizontal air intake often results in the film being thicker at the front and thinner at the back, leading to uneven film thickness, this embodiment sets a rotating component 4 at the lower part of the second plate. The rotating component 4 rotates to drive the substrate 33 to rotate, thereby changing the defects in the upper and lower gas flow fields in the reaction space, compensating for the material growth difference caused by the horizontal air intake, and further improving the uniformity of growth.

[0064] Furthermore, the rotating component 4 is disposed at the lower part of the reaction component 3. The rotating component 4 is capable of rotating around its own central axis, causing the substrate 33 to rotate around the central axis of the reaction chamber 1 along with the rotating component 4. Furthermore, the central axis of the rotating component 4 coincides with the central axis of the reaction chamber 1.

[0065] The rotating assembly 4 includes a shaft, a tray 41, a rotating cylinder 42, and a rotating magnetohydrodynamic fluid 43. The tray 41 is used to carry and support the reaction assembly 3, and the substrate 33 is secured to the upper center of the tray 41. The rotating cylinder 42 is engaged with the tray 41 in a cylindrical shape and rotates under the drive of a driving component. Exemplarily, the driving component is a motor.

[0066] In this embodiment, the rotating component 4 drives the substrate 33 to rotate. The airflow enters from one side of the reaction space between the first plate 31 and the second plate 32. When the substrate 33 and the reaction space rotate, a spiral airflow is formed, which improves the uniformity of the lateral distribution of the covered area, effectively improves the film deposition rate, and reduces local accumulation.

[0067] Furthermore, the rotating assembly 4 also includes a rotating magnetic fluid 43. The rotating magnetic fluid 43 is disposed in the lower part of the rotating cylinder 42. The rotating magnetic fluid 43 has a hollow structure and is used for rotational sealing.

[0068] Furthermore, it also includes a heating component. The heating component is disposed within the rotating component 4, specifically within the rotating cylinder 42.

[0069] The heating assembly includes multiple independent temperature-controlled electrodes 5 distributed at different radii on the lower part of the tray 41. Each independent temperature-controlled electrode 5 precisely controls the temperature of a specific area, achieving temperature gradient adjustment, improving the uniformity of the thermal field distribution on the substrate 33 surface, and reducing film stress unevenness and crystallization defects caused by local overheating or insufficient temperature. Each independent temperature-controlled electrode is connected to a temperature control module, which provides real-time feedback and dynamically adjusts the heating power. Combined with the airflow uniformity brought about by rotation, this further enhances the stability of large-area deposition.

[0070] To address the issue of uneven thermal field on the substrate surface, this embodiment includes three independent temperature control electrodes 5, forming a three-zone gradient heating system. The three zones are temperature-controlled separately, corresponding to the center, middle ring, and edge regions of the substrate 33, respectively. The temperature parameters of each zone are adjusted according to actual growth requirements.

[0071] In this embodiment, the gas intake is controlled by partitioning to effectively control the layered gas intake density and increase the MO deposition rate. The carrier gas pipe 22 is horizontally stacked and the water box 24 centrally cools the carrier gas pipe 22, shortening the reaction distance by 75% and reducing the distance between the nozzle and the substrate 33 by 34%. The rotation generates a spiral airflow to dynamically compensate for the gas deposition on the substrate 33, and the independent partitioned temperature control and the coupling effect of the flow field and temperature field achieve a lateral average distribution of the covered area, effectively improving the uniformity of thin film deposition and achieving a thin film non-uniformity of <2%.

[0072] Example 2 This embodiment discloses a thin film growth method, which uses the atmospheric pressure MOCVD reactor of Example 1.

[0073] The thin film growth method is as follows: Step 1: Introduce MO source gas, carrier gas, and ammonia according to the set ratio; Step 2: Ammonia and MO source gas react in reaction component 3, and exhaust gas is discharged.

[0074] Step 1 includes: Step 1.1: Introduce MO source gas and ammonia gas according to the set ratio; Specifically, it includes: According to the required ratio of ammonia and MO source gas, they enter the first gas chamber 211, the second gas chamber 212, and the third gas chamber 213 through the first nozzle 231, the second nozzle 232, and the third nozzle 233, respectively. Specifically, the first nozzle 231 is filled with ammonia, the second nozzle 232 is filled with MO source gas and carrier gas, and the third nozzle 233 is filled with ammonia.

[0075] Step 1.2: MO source gas and ammonia gas enter the reaction assembly 3 through carrier gas pipe 22.

[0076] Ammonia in the first gas chamber 211, MO source gas and carrier gas in the second gas chamber 212, and ammonia in the third gas chamber 213 enter the reaction assembly 3 through the bottom through-holes via the first carrier gas pipe 221, the second carrier gas pipe 222, and the third carrier gas pipe 223, respectively.

[0077] The first air carrier pipe 221, the second air carrier pipe 222, and the third air carrier pipe 223 are horizontally stacked in the water box 24, and the cooling water in the water box 24 cools the first air carrier pipe 221, the second air carrier pipe 222, and the third air carrier pipe 223.

[0078] The second carrier gas pipe 222 is higher than the third carrier gas pipe 223 and lower than the first carrier gas pipe 221 at the jet end of the reaction assembly 3.

[0079] Step 2 includes: Step 2.1: Driven by the motor, the rotating component 4 rotates; The rotating component 4 rotates, causing the substrate 33 to rotate. The airflow enters from one side of the reaction space and forms a spiral airflow when the substrate 33 and the reaction space rotate, achieving a lateral uniform distribution of the covered area, effectively improving the uniformity of thin film deposition and reducing local accumulation.

[0080] Step 2.2: The independent temperature control electrode 5 starts heating to form a gradient heating area; The independent temperature control electrode 5 starts heating. Since the independent temperature control electrode 5 is distributed at different radii, the substrate 33 forms different annular temperature rings, forming a three-zone gradient heating. The three zones are temperature controlled separately, and the temperature parameters of each zone are adjusted according to the actual growth requirements.

[0081] Since the deposition rate of the compound is related to the height in the reaction space, the upper and lower layers are inlet gas for ammonia, and the middle layer is inlet gas for MO. The lower layer has a higher temperature and preferentially mixes and reacts with the middle layer. After a certain distance, the density of ammonia in the lower layer decreases, and ammonia in the upper layer compensates for it, which enables the material to grow well even at a position far away from the jet end of the carrier gas pipe 22.

[0082] By dynamically adjusting the power distribution of the independent temperature control electrode 5, the temperature field gradient deviation caused by the air intake direction is compensated, enabling the substrate 33 to achieve spatial thermal equilibrium during continuous rotation. The coupling effect of the flow field and temperature field achieves a lateral average distribution over the covered area, effectively improving the uniformity of thin film deposition and achieving a thin film non-uniformity of <2%.

[0083] Step 2.3: After the reaction is complete, the exhaust gas is discharged from the exhaust pipe 11.

[0084] During rotation, cooling water continuously flows through the water box 24 to cool the carrier gas pipe 22 and the gas inside it, preventing pre-reaction of the gas. The exhaust pipe 11 promptly discharges reaction byproducts to avoid backflow contamination. The entire deposition process is carried out under the coordinated control of a gradient temperature field and spiral airflow to ensure film composition consistency and thickness uniformity.

[0085] Example 3 To address the issue that the support structure of tray 41 and substrate 33 cannot accommodate trays 41 and substrate 33 of various sizes, this embodiment is an improvement upon Embodiment 1. For example... Figure 4 As shown, in this embodiment, a gear set 44 and a retractable carrier disk 45 are configured to engage with the tray 41 to improve adaptability to substrates 33 and trays 41 of different sizes and increase the utilization rate of the rotating component 4. The gear set 44 achieves stable rotation of the carrier disk 45 through meshing transmission. The retractable structure adjusts the support range according to the size of the substrate 33, making the center of gravity coincide with the axis of rotation and reducing airflow disturbance caused by eccentricity. In order to accommodate the carrier disk 45 and the gear set 44, the heating component in this embodiment is an independent annular heating element (not shown in the figure) located at the bottom of the tray 41, which is controlled by an external power distribution module.

[0086] In this embodiment, the tray 41 is adapted to the substrate 33. The substrate 33 is snapped onto the tray 41, becoming an integral part of the tray 41. The carrier tray 45 is disposed at the lower part of the tray 41. The carrier tray 45 is connected to the tray 41 through a telescopic structure, adapting to substrates 33 and trays 41 of different diameters, improving the versatility of the equipment. The carrier tray 45 is driven to rotate by a gear set 44, ensuring stable transmission and reducing the impact of vibration on thin film growth.

[0087] like Figure 4 As shown, the carrier plate 45 includes a support frame 451 coaxially arranged with the rotation axis of the rotating assembly 4 and a telescopic rod 452 slidably connected to the support frame 451. Figure 5 As shown, the support frame 451 is centrally fitted outside the rotating shaft, and multiple protruding rods 4511 are radially arranged around it. Each protruding rod 4511 has an upward-opening T-shaped groove along its length. The telescopic rod 452 includes an arc-shaped portion 4521 and a telescopic portion 4522. The telescopic portion 4522 of the telescopic rod 452 is disposed within the T-shaped groove and can slide within the T-shaped groove to expand or shrink the carrier plate 45. The upper part of the T-shaped groove limits the telescopic rod 452.

[0088] The height of the edge of the arc-shaped part 4521 is greater than the height of the telescopic part 4522 of the telescopic rod 452, so as to fix the trays 41 of different sizes.

[0089] The gear set 44 includes a gear disk 442 and a drive gear 441. The gear disk 442 meshes with the drive gear 441, and the rotation of the drive gear 441 drives the gear disk 442 to rotate. The central shaft of the drive gear 441 has an extension, which can be manually rotated to rotate the drive gear 441 and drive the gear disk 442 to rotate. The extension has threads and is locked with a nut after adjustment.

[0090] like Figure 5 As shown, the support frame 451 has a protrusion 4512 between the two extension rods 4511, and the drive gear 441 is disposed on the protrusion 4512.

[0091] The gear disk 442 is centrally fitted onto the rotating shaft of the rotating assembly 4 and supported by a bearing (not shown). The gear disk 442 has multiple arc-shaped through slots 4421, exemplarily with a central angle of 45°. The arc-shaped through slots 4421 extend obliquely outward from the central axis of the gear disk 442. Each arc-shaped through slot 4421 includes a first end and a second end.

[0092] Furthermore, a pin is fixed to the upper part of the portion of the telescopic rod 452 that is located in the T-shaped groove. Multiple pins are disposed within corresponding arc-shaped through grooves 4421 and are able to move within the arc-shaped through grooves 4421. When the pin is located at the first end, the telescopic rod 452 is at its shortest; when the pin is located at the second end, the telescopic rod 452 is at its longest.

[0093] When the gear disk 442 rotates, multiple pins move in the corresponding arc-shaped through grooves 4421, driving multiple telescopic rods 452 to slide in the T-shaped grooves, so that the multiple telescopic rods 452 extend or shorten synchronously, so that the carrier disk 45 expands or shrinks to adapt to substrates 33 of different sizes.

[0094] When the drive gear 441 rotates, power is transmitted to the gear disk 442, causing it to rotate synchronously. The pin slides along an inclined path within the arc-shaped through groove 4421, pushing the telescopic rod 452 to move outward or inward, thus achieving continuous adjustment of the diameter of the carrier disk 45. The inclination angle of the arc-shaped through groove 4421 matches the movement trajectory of the pin, ensuring that the telescopic rods 452 extend and retract in unison. This allows for clamping substrates 33 and trays 41 of different sizes, and the carrier disk 45 remains balanced even when clamping substrates 33 and trays 41 of different sizes. The ends of the arc-shaped portions can fit snugly against the edges of the trays 41, providing stable support. By adjusting the forward and reverse rotation of the drive gear 441, it is possible to quickly switch between substrates 33 and trays 41 of different diameters.

[0095] In this embodiment, the rotation shaft of the drive gear 441 is manually rotated to drive the gear disk 442 to rotate, thereby causing the telescopic rod 452 to extend and retract synchronously. Compared with the poor stability and complex structure of power drive structures such as power supply and electronic control, the gear drive structure of this embodiment has high stability and simple structure. The drive gear 441 is a small gear, which drives the large gear disk, which can amplify the torque and avoid the phenomenon that the extension and retraction cannot work due to insufficient load when the motor is driven. Moreover, the power is directly transmitted without power loss. The drive gear 441 is a small gear, which is set on one side of the gear disk 442. After being eccentrically arranged, it will not affect the radial rotation radius of the carrier disk 45, will not occupy the central rotation shaft space of the gear disk 442, and will not interfere with the rotation shaft or the telescopic rod 452. The accuracy of the telescopic rod 452's extension and retraction directly determines the concentricity of the substrate 33 and the clamping position accuracy. The manual drive gear meshing accuracy is higher, and the telescopic rod 452 can be extended and retracted slightly with a small angle rotation. It can precisely adjust the clamping radius and adapt to precision substrates 33 and trays 41 of different sizes. It does not rely on the electrical control accuracy of motor encoders and drivers, and there will be no adjustment deviation caused by electrical control signal delay or motor step loss.

[0096] Furthermore, the arc-shaped through groove 4421 can adapt to the multi-station requirements of the carrier tray 45 and accommodate the clamping of different specifications of trays 41 and substrates 33. The extension and retraction of each telescopic rod are consistent, so that the clamping radius of all stations of different specifications of trays 41 and substrates 33 is consistent, thereby improving the overall balance of the carrier tray 45.

[0097] In this embodiment, the gear set 44 and the carrier plate 45 jointly support the tray 41 and the substrate 33, so that the substrate 33 rotates smoothly, improving the uniformity of gas mixing and thin film deposition. Combined with the zoned control of the annular heating plate, the temperature distribution uniformity of substrates 33 of different sizes is improved during rotation.

[0098] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An MOCVD reactor for atmospheric pressure growth, characterized in that, It includes a reaction chamber (1), an air intake assembly (2), and a reaction assembly (3); The reaction assembly (3) is located at the center of the reaction chamber (1), and the gas inlet assembly (2) is located on the first side of the reaction assembly (3) to provide reaction gas to the reaction assembly (3); The reaction chamber (1) is provided with an exhaust pipe (11), which is located on the second side of the reaction assembly (3), with the first side and the second side opposite to each other.

2. The MOCVD reactor for atmospheric pressure growth according to claim 1, characterized in that, The air intake assembly (2) includes a carrier gas pipe (22), through which the reaction gas enters the reaction assembly (3).

3. The MOCVD reactor for atmospheric pressure growth according to claim 2, characterized in that, It also includes a nozzle (23) which is connected to the carrier gas pipe (22).

4. The MOCVD reactor for atmospheric pressure growth according to claim 1, characterized in that, The exhaust pipe (11) has its opening facing downwards; the exhaust pipe (11) is an inverted conical structure and is used to discharge the waste gas generated by the reaction assembly (3).

5. The MOCVD reactor for atmospheric pressure growth according to claim 1, characterized in that, It also includes a rotating component (4); the reaction component (3) includes a substrate (33), the rotating component (4) is disposed at the lower part of the substrate (33), and the substrate (33) rotates with the rotating component (4).

6. The MOCVD reactor for atmospheric pressure growth according to claim 5, characterized in that, The rotating component (4) includes a rotating magnetofluid (43) disposed outside the rotating component (4).

7. The MOCVD reactor for atmospheric pressure growth according to claim 6, characterized in that, The rotating assembly (4) includes a gear set (44) and a carrier disk (45); the carrier disk (45) is used to fix the tray (41) and the substrate (33), and the gear set (44) is used to adjust the size of the carrier disk (45).

8. The MOCVD reactor for atmospheric pressure growth according to claim 5, characterized in that, It also includes a heating component disposed inside the rotating component (4); the heating component is radially distributed along the substrate (33).

9. The MOCVD reactor for atmospheric pressure growth according to claim 8, characterized in that, The heating component is an independent temperature control electrode (5).

10. A method for growing a thin film, characterized in that, The MOCVD reactor used for atmospheric pressure growth according to any one of claims 1-9 specifically includes the following steps: Step 1: Introduce MO source gas, carrier gas, and ammonia according to the set ratio; Step 2: Ammonia and MO source gas react in the reaction component (3) and exhaust gas is discharged.

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