Compact mocvd high temperature rapid deposition apparatus for liquid organic sources

Abstract

A compact MOCVD high-temperature rapid deposition device for liquid organic sources relates to chemical vapor deposition technology.The present application comprises a reaction chamber, a spraying device and a deposition table, characterized in that the reaction chamber is provided with an atomizing device and an evaporation chamber, the evaporation chamber has a temperature adjusting device, and the evaporation chamber is a semi-closed structure with an outlet; the atomizing device has a liquid inlet pipe and an air inlet pipe, and the outlet of the atomizing device is arranged in the evaporation chamber; the outlet of the evaporation chamber is arranged on one side close to the deposition table, and the evaporation chamber outlet is provided with a spraying plate.The present application improves the stability of the equipment and is easier to maintain.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical vapor deposition technology. BACKGROUND

[0002] Metal-organic Chemical Vapor Deposition (MOCVD) is a new type of vapor growth technology based on the development of vapor growth, which is convenient to control, and is suitable for both laboratory research and large-scale production. When preparing different materials, the growth temperature and growth rate need to be set differently according to the characteristics of the materials. For YBa2Cu3O 7-δ The traditional MOCVD equipment has poor high-temperature rapid growth film capability.

[0003] In addition, for the preparation of thin films by MOCVD method, the evaporator of the traditional MOCVD equipment is arranged outside the reaction chamber, and the liquid metal organic source needs to be flashed into a gaseous state in the evaporator outside the reaction chamber, and then transported to the shower head in the reaction chamber through the gas conveying pipe, and then sprayed onto the substrate surface by the shower head. In the process of transporting the gaseous evaporation source, a part of the evaporation source will inevitably adhere to the inner wall of the gas conveying pipe. The concentration and composition of the organic source reaching the substrate surface are quite different from those of the liquid organic source entering the evaporation chamber, and the difference will gradually increase with the use time. The utilization rate of the metal organic source is low, and the growth rate and composition of the thin film will also be seriously affected. Even the gas conveying pipe is completely blocked by the organic source, causing damage to the equipment. In the process of high-temperature rapid deposition, the concentration of the evaporation source is high, and the adsorption of part of the evaporation source on the gas conveying pipe will have a great influence on the growth rate and thickness of the thin film. The evaporator, shower head and gas inlet pipe need to be continuously heated to a high temperature during the growth of the thin film, which requires high consistency and stability of temperature control, and the energy consumption is also large. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a MOCVD high-temperature rapid deposition device with low energy consumption and high consistency.

[0005] The technical solution adopted by the present application to solve the technical problem is a compact MOCVD high-temperature rapid deposition device for liquid organic source, comprising a reaction chamber, a spraying device and a deposition table, characterized in that the reaction chamber is provided with an atomizing device and an evaporation chamber, the evaporation chamber has a temperature adjusting device, and the evaporation chamber is a semi-closed structure with an outlet; the atomizing device has a liquid inlet pipe and a gas inlet pipe, and the outlet of the atomizing device is arranged inside the evaporation chamber; the outlet of the evaporation chamber is arranged on one side close to the deposition table, and there is a spraying plate at the outlet of the evaporation chamber.

[0006] The evaporation chamber is arranged above the deposition table. The temperature adjusting device is a cooling pipe arranged around the evaporation chamber.

[0007] The liquid inlet pipe and the air inlet pipe of the atomizing device are arranged in a concentric sleeve pipe mode, the liquid inlet pipe is arranged inside the air inlet pipe, and the pipe diameter of the air inlet pipe gradually converges towards the outlet of the atomizing device. A dispersion baffle with holes is arranged in the evaporation chamber, the dispersion baffle divides the evaporation chamber into an atomizing area and a spraying area, the spraying area is between the dispersion baffle and the spraying plate, and the outlet of the atomizing device is located in the atomizing area.

[0008] Further, the evaporation chamber is cylindrical, the atomizing device penetrates through the closed top surface of the cylinder and is arranged inside the cylinder, and the bottom surface of the cylinder is the spraying plate.

[0009] By using the technology of the present application, high-temperature rapid preparation of a compact MOCVD for liquid organic sources can be realized. The evaporation chamber of the present application is adjustable in distance from the deposition table. During the high-temperature rapid deposition of a thin film, only the deposition table needs to be heated, and the heat radiation of the deposition table can complete the heating of the evaporation chamber, without the need for additional heating of the evaporation chamber, thereby saving energy. The evaporation chamber integrated with the shower head is redesigned, the MOCVD equipment is simplified, the stability of the equipment is improved, and the equipment is easier to maintain. The liquid metal organic source enters the evaporation chamber in the deposition cavity, is directly sprayed uniformly onto the substrate through the spraying port after being flashed into a gaseous organic source, the transport path of the liquid organic source to the substrate is shorter, the high-temperature rapid growth of a thin film of multiple compounds can be realized, the composition of the thin film is more stable and controllable, the growth uniformity is better, and the utilization rate of the metal organic source is improved. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is an embodiment schematic diagram of a high-temperature rapid deposition cavity of a compact MOCVD for liquid organic sources of the present application.

[0011] Figure 2 is Figure 1 is an installation schematic diagram of a MOCVD air inlet pipe and a liquid inlet pipe and an upper partition plate of an evaporation chamber.

[0012] Figure 3 is a structure schematic diagram of a high-temperature rapid deposition equipment of an embodiment.

[0013] Figure 4 is an X-ray diffraction 2theta scan diagram of a sample of an embodiment.

[0014] Figure 5 is a half-height width value of an X-ray diffraction omega scan curve of a sample of an embodiment.

[0015] Figure 6 is a half-height width value of an X-ray diffraction phi scan curve of a sample of an embodiment.

[0016] Figure 7 is a simple diagram of an evaporation chamber of embodiment 1.

[0017] Figure 8 is a simplified diagram of the evaporation chamber of Example 2.

[0018] Reference numerals: 100 - evaporation chamber top plate, 101 - cooling pipe, 102 - shower plate, 103 - evaporation chamber upper layer partition, 104 - connecting flange, 105 - evaporation chamber upper metal pipe, 106 - evaporation chamber, 107 - gas inlet pipe, 108 - dispersion partition, 109 - liquid inlet pipe, 110 - evaporation chamber upper layer partition center hole. 201 - sample table, 202 - deposition table, 203 - heating wire, 204 - connecting piece, 205 - rotating shaft, 206 - reaction chamber structure. DETAILED DESCRIPTION

[0019] As Figures 1-3 , the compact MOCVD high-temperature rapid deposition device for liquid organic sources includes a reaction chamber (formed by the reaction chamber structure 206), a shower plate 102 and a deposition table 202, an atomization device and an evaporation chamber 106 are arranged in the reaction chamber, a cooling pipe 101 is used as a temperature adjusting device of the evaporation chamber 106, and the evaporation chamber 106 is a semi-closed structure with an outlet; the atomization device has a liquid inlet pipe 109 and a gas inlet pipe 107, and the outlet of the atomization device is arranged inside the evaporation chamber 106; the outlet of the evaporation chamber 106 is arranged on the side close to the deposition table 202, and the evaporation chamber outlet is provided with the shower plate 102.

[0020] The evaporation chamber is arranged above the deposition table 202. The liquid inlet pipe and the gas inlet pipe of the atomization device are arranged in a concentric sleeve manner, the liquid inlet pipe is arranged inside the gas inlet pipe, and the pipe diameter of the gas inlet pipe gradually converges towards the outlet of the atomization device.

[0021] The evaporation chamber is provided with a dispersion partition 108 with holes, which divides the evaporation chamber into an atomization area and a spraying area, and the spraying area is between the dispersion partition 108 and the shower plate 102, and the pipeline of the atomization device passes through the center hole of the evaporation chamber upper layer partition to enter the atomization area.

[0022] Further, the evaporation chamber is cylindrical, the top is closed, the bottom is a shower plate, and the atomization device is arranged inside the cylinder through the top of the cylinder.

[0023] The first alternative way (Example 1) is that the pipeline of the atomization device passes through the evaporation chamber top plate 100 and the evaporation chamber upper layer partition 103, and enters the atomization area through the center hole 110 of the evaporation chamber upper layer partition, as shown in Figure 2 and Figure 7 .

[0024] The second alternative way (Example 2) is that the upper layer partition of the evaporation chamber is the top plate of the evaporation chamber, as shown in Figure 8 .

[0025] The heating wire in the deposition table uniformly heats the deposited sample and radiantly heats the evaporation chamber. The gas inlet pipe of the atomizing device is inserted into the small hole of the evaporation chamber partition, and the liquid pipe is nested in the gas inlet pipe.

[0026] During the thin film growth, the liquid metal organic source is blown into fine and uniform mist under the action of gas into the two-layer partition sandwich space of the evaporation chamber. The outer wall of the evaporator of the evaporation chamber partition to the spray plate is uniformly wound with a cooling pipe to control the temperature of the evaporation chamber, so that the mist metal organic source is evaporated into a uniform gaseous evaporation source. The gaseous evaporation source is further improved in uniformity by the dispersion partition, and is sprayed through the spray plate below the evaporation chamber.

[0027] Figure 4 It is shown in Table 2 that the diffraction peaks of the two samples grown by high-temperature rapid deposition are very sharp and have no impurity peaks, and the crystalline quality of the sample surface is very good.

[0028] Figure 5 It is shown in Table 3 that the omega scan half-width values of the two samples are small, indicating that the sample out-of-plane orientation is good.

[0029] Figure 6 It is shown in Table 4 that the phi scan half-width values of the two samples are small, indicating that the sample in-plane orientation is good.

[0030] Finally, the device of the application is used as Figure 1 The distance between the deposition table and the evaporation chamber is adjusted to 3 cm. A piece of strontium titanate substrate with a diameter of 3 inches, a thickness of 0.5 mm and a c-axis tilt of 12° is placed on the sample table of the deposition table. The reaction cavity of the MOCVD system is vacuumed to 3 Pa. The La source, the Ca source and the Mn source are dissolved in tetrahydrofuran according to a molar ratio of 1.8:4.2:6.5, and after being stirred sufficiently, a uniform and clear metal organic source solution is formed. The power supply is turned on to heat the deposition table to 830℃, the water cooling is turned on to reduce the temperature of the evaporation chamber to 330℃, and the rotation of the deposition table is turned on. After the temperature and the pressure are stable, the metal organic source solution is mixed with the reaction gas by using a peristaltic pump, and is sent into the evaporation chamber to flash into metal organic source vapor. The metal organic source vapor is sprayed on the surface of the crystal substrate by the spray plate, and a La 1-x Ca x MnO3 thin film is grown at a rate of 200 nm / min. After the deposition is completed, the heating power supply is turned off, and after the substrate is cooled, the thin film sample is taken out for annealing treatment. One experiment is repeated, and the thin film sample is characterized. The structure and morphology of the prepared thin film are shown in Figures 4-6 It can be seen from the figure that the thin film prepared by using the high-temperature deposition device of the application has high crystalline quality and good orientation.

[0031] The application redesigns the MOCVD deposition cavity, the distance between the redesigned integrated evaporation spray chamber and the deposition table is closer, which can be used for high-temperature rapid growth of large-size substrate film, only the deposition table needs to be heated during film growth, the heat radiation of the deposition table can complete the heating of the evaporation chamber, the evaporation chamber does not need to be additionally heated, the evaporation chamber side wall is uniformly wound with cooling pipes to assist temperature control, which can effectively save energy; the liquid metal organic source enters the evaporation chamber in the deposition cavity, is directly sprayed to the substrate through the spray port after being flashed into gaseous organic source, the transport path of the liquid organic source to the substrate is shorter, the high-temperature rapid growth of various compound films can be realized, the film composition is more stable and controllable, the growth uniformity is better, and the utilization rate of the metal organic source is improved.

Claims

1. A compact MOCVD high temperature rapid deposition device for liquid organic sources, comprising a reaction chamber, a spraying device and a deposition table, characterized in that, The reaction chamber is provided with an atomizing device and an evaporation chamber, the evaporation chamber is provided with a temperature adjusting device, and the evaporation chamber is a semi-closed structure with an outlet; the atomizing device is provided with a liquid inlet pipe and an air inlet pipe, and the outlet of the atomizing device is arranged in the evaporation chamber; the outlet of the evaporation chamber is arranged on the side close to the deposition table, and the evaporation chamber outlet is provided with a spray plate; the liquid inlet pipe and the air inlet pipe of the atomizing device are arranged in a concentric sleeve pipe mode, the liquid inlet pipe is arranged in the air inlet pipe, and the pipe diameter of the air inlet pipe gradually converges towards the outlet of the atomizing device; the evaporation chamber is provided with a perforated dispersion partition plate, the dispersion partition plate divides the evaporation chamber into an atomizing area and a spraying area, the spraying area is between the dispersion partition plate and the spray plate, and the outlet of the atomizing device is located in the atomizing area; the evaporation chamber is in a cylindrical shape, the atomizing device penetrates through the closed top surface of the cylinder and is arranged in the cylinder, and the bottom surface of the cylinder is the spray plate; the evaporation chamber is adjustable in distance from the deposition table, and only the deposition table needs to be heated in the high-temperature rapid deposition process of the thin film.

2. The compact MOCVD high temperature rapid deposition apparatus for liquid organic sources of claim 1, wherein, The evaporation chamber is arranged above the deposition table.

3. The compact MOCVD high temperature rapid deposition apparatus for liquid organic sources of claim 1, wherein, The temperature adjusting device is a cooling pipe arranged around the evaporation chamber.

4. The compact MOCVD high temperature rapid deposition apparatus for liquid organic sources of claim 1, wherein, The deposition table is installed in the reaction chamber through a rotating shaft and a bearing.

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