Atomic layer deposition gas supply system for low saturated vapor pressure precursor source

Abstract

The invention discloses an atomic layer deposition gas supply system for a low saturated vapor pressure precursor source, and belongs to the technical field of atomic layer deposition reaction equipment. According to the system, a mass flow controller is combined with an original gas inlet pneumatic valve, so that the gas quantity in a precursor source bottle in the deposition process is accurately controlled; the pressure in the precursor source bottle is monitored in real time through a pressure meter, so that the temperature in the deposition process is accurately controlled; in addition, specific contents of precursor source gas and auxiliary gas in source gas are monitored in real time through a gas analyzer at a source outlet, so that a system is assisted to judge whether reaction gas needs to be supplemented or not; the mass flow controller, the pressure meter and the gas analyzer are all connected with the PLC, and control of all the parts is achieved through the PLC; and gas control, pressure monitoring and component monitoring of the low saturated vapor pressure precursor source in the experiment process are realized.

Description

Technical Field

[0001] The present invention relates to an atomic layer deposition gas supply system for a low saturated vapor pressure precursor source, belonging to the technical field of atomic layer deposition reaction equipment. Background Art

[0002] Atomic layer deposition technology is a special chemical vapor deposition technology. In this process, two different precursor sources are alternately introduced into a heated vacuum chamber (also known as a reaction chamber), enabling the precursor sources to alternately undergo saturated chemical adsorption on the substrate surface, thereby self-limiting the growth of a thin film with an atomic layer thickness. Atomic layer deposition technology has the advantages of low-temperature deposition, high film purity, and high coverage, making it suitable for thin film preparation in different temperature environments. In addition, this technology also has high controllability, and the generated thin film has good uniformity, playing an increasingly important role in semiconductor manufacturing and new energy technologies.

[0003] In an ideal atomic layer deposition reaction, the precursor needs to enter the vacuum chamber in the form of a gaseous reactant. Therefore, for the precursor source used in atomic layer deposition reactions, one of the most important parameters is the saturated vapor pressure. The so-called saturated vapor pressure is the pressure of the vapor in phase equilibrium with a solid or liquid in a closed condition at a certain temperature. The same substance has different saturated vapor pressures at different temperatures, and the saturated vapor pressure increases with the increase in temperature. For the same substance, the saturated vapor pressure of the solid state is less than that of the liquid state. In the classic atomic layer deposition reaction process of depositing an aluminum oxide thin film using trimethylaluminum and water as precursors, both trimethylaluminum and water are reactants with relatively high saturated vapor pressures. Therefore, the reaction can be carried out without heating the precursor source. However, with the development of atomic layer deposition technology, the types of thin films to be deposited are increasing, and thus the types of precursor sources developed are also increasing. However, not every precursor source has a high saturated vapor pressure like trimethylaluminum and water. Therefore, in order to improve the volatility of the precursor source, it is necessary to heat the precursor source. For example, Chinese Patent No. CN218321627U discloses an atomic layer deposition device and a source bottle heating device for an atomic layer deposition device, achieving a good heating effect by designing a heating device that fits the source bottle, and making disassembly and assembly more convenient using a split design.

[0004] However, for a precursor source with an extremely low saturated vapor pressure, in order to fully vaporize and volatilize the precursor source, it is usually necessary to heat the precursor source to a relatively high temperature. And in order to prevent the precursor source from condensing in the manual valve, during the heating process, the manual valve on the precursor source cylinder usually needs to be heated as well. However, the manual valve of the precursor source cylinder usually uses a diaphragm valve, and the diaphragm valve has a relatively low temperature tolerance, usually around 120 °C. Therefore, when the heating temperature of the precursor source is too high, it will cause irreversible damage to the manual valve, resulting in the loss of the sealing function of the manual valve of the precursor source cylinder. In order to reduce the heating temperature of the precursor source, Chinese Patent No. CN103710683A discloses a source bottle applied to an atomic deposition device. By inserting a bubbling tube into the source bottle and introducing an auxiliary gas into the bubbling tube, the auxiliary gas enters the source bottle through the bubbling tube and drives the precursor source to volatilize towards the source outlet. By expanding the contact area between the carrier gas and the liquid source, the carrier gas carrying efficiency is improved while reducing the ineffective loss of the liquid source, saving the liquid source resources.

[0005] However, in the actual use process of the above bubbling type source bottle and the heating device, the following problems still exist, resulting in the inability to supply gas stably and effectively:

[0006] (1) Lack of an effective gas control system, unable to control the amount of auxiliary gas entering the source bottle during the deposition process and keep it stable;

[0007] (2) Lack of an effective pressure monitoring system, unable to determine the appropriate heating temperature required for deposition;

[0008] (3) Lack of an effective component monitoring system, unable to determine whether the volatilized gas is the auxiliary gas or the precursor source itself. Moreover, even if a pressure detection device is added to the existing gas supply system, considering that the gas components cannot be distinguished, effective gas supply cannot be guaranteed. Summary of the Invention

[0009] In order to solve the problems existing in the prior art, the present invention provides an atomic layer deposition gas supply system for a low saturated vapor pressure precursor source. By improving the existing gas supply system, real-time monitoring of the precursor source entering the reaction chamber is achieved. On the premise of ensuring the supply amount of the precursor source, the amount of carrier gas entering the carrier gas-assisted precursor source bottle can be precisely controlled, and the pressure inside the precursor source bottle can be monitored in real time during the experiment, which is convenient for determining the heating temperature of the precursor source. In addition, the gas components at the source outlet can be monitored in real time during the experiment, which is convenient for judging the content of the auxiliary gas and the precursor source itself in the gas flowing out of the source outlet.

[0010] An atomic layer deposition gas supply system for a low saturation vapor pressure precursor source, which is used to provide gaseous precursors to the reaction chamber of an atomic layer deposition device, includes: a carrier gas assisted precursor source bottle, a heating device, a precursor source pressure gauge, a gas analyzer, an auxiliary gas storage tank, and a PLC controller;

[0011] Among them, the heating device is used to heat the precursor source in the carrier gas assisted precursor source bottle, the precursor source pressure gauge is used to monitor the pressure in the carrier gas assisted precursor source bottle in real time, the gas analyzer is used to analyze the gas composition in the carrier gas assisted precursor source bottle, the auxiliary gas storage tank is used to store auxiliary gas, and the PLC controller is used to control the heating temperature of the heating device and the amount of auxiliary gas entering the carrier gas assisted precursor source bottle according to the pressure and gas composition in the carrier gas assisted precursor source bottle.

[0012] Furthermore, the atomic layer deposition gas supply system includes: a carrier gas assisted precursor source bottle 1, a flexible heating sleeve 2, an inlet manual valve 4, an outlet manual valve 5, an inlet pneumatic valve 7, a PLC controller 8, an auxiliary gas storage tank 9, a storage pressure gauge 10, a mass flow controller 11, a carrier gas cylinder 12, a vacuum pump 13, a side extraction pneumatic valve 14, a precursor source pressure gauge 15, a gas analyzer 16, and an outlet pneumatic valve 17.

[0013] A flexible heating sleeve 2 is provided outside the carrier gas assisted precursor source bottle 1 (hereinafter referred to as source bottle 1) for heating source bottle 1 and indirectly heating the precursor source 3 inside source bottle 1 by means of heat conduction. An inlet and an outlet are provided above source bottle 1. The inlet extends to the bottom of source bottle 1, and the outlet extends to the top of source bottle 1. An inlet manual valve 4 is provided at the inlet, and an outlet manual valve 5 is provided at the outlet. The inlet manual valve 4 and the outlet manual valve 5 are used to achieve sealing during the installation and disassembly of source bottle 1, preventing the precursor source 3 from deteriorating after contacting air.

[0014] An inlet pneumatic valve 7 is provided outside the inlet manual valve 4. The inlet pneumatic valve 7 is connected to the PLC controller 8, and the opening time of the inlet pneumatic valve 7 can be precisely controlled by the PLC controller 8, thereby precisely controlling the time for the auxiliary gas to enter source bottle 1.

[0015] An auxiliary gas storage tank 9 is provided outside the inlet pneumatic valve 7. A storage pressure gauge 10 is provided on the auxiliary gas storage tank 9, and a mass flow controller 11 is provided outside. Both the storage pressure gauge 10 and the mass flow controller 11 are connected to the PLC controller 8. The pressure of the storage pressure gauge 10 can be monitored in real time by the PLC controller 8, and the flow rate of the mass flow controller 11 can be set by the PLC controller 8.

[0016] The mass flow controller 11 is connected to the carrier gas cylinder 12 which is used to supply the carrier gas. The carrier gas is generally an inert gas such as nitrogen or argon. A bypass pumping line connecting to the vacuum pump 13 is provided between the auxiliary gas storage tank 9 and the intake pneumatic valve 7. A bypass pneumatic valve 14 is provided on the bypass pumping line. The bypass pneumatic valve 14 is connected to the PLC controller 8. The PLC controller 8 can accurately control the opening time of the bypass pneumatic valve 14 to discharge the excess stored gas in the auxiliary gas storage tank 9.

[0017] Outside the outlet manual valve 5, a precursor source pressure gauge 15 and a gas analyzer 16 are provided. Both the precursor source pressure gauge 15 and the gas analyzer 16 are connected to the PLC controller 8. The pressure of the precursor source pressure gauge 15 can be monitored in real time through the PLC controller 8. By comparing the pressure of the gas volatilized from the source bottle 1 and the saturated vapor pressure of the precursor source 3, the heating temperature of the source bottle 1 can be determined. The composition and content of the gas volatilized from the source bottle 1 obtained by the gas analyzer 16 can be monitored in real time through the PLC controller 8. Then, it can be determined whether the content of the precursor source vapor in the mixed gas volatilized from the source bottle 1 is sufficient (which can be determined according to experience). Outside the precursor source pressure gauge 15 and the gas analyzer 16, an outlet pneumatic valve 17 is provided. The outlet pneumatic valve 17 is connected to the PLC controller 8. The opening time of the outlet pneumatic valve 17 can be accurately controlled through the PLC controller 8 to accurately control the time for the mixture of the auxiliary gas and the precursor source vapor to enter the reaction chamber 6.

[0018] Before the experiment, first start the vacuum pump 13 through the PLC controller 8 to keep the system in an ultimate vacuum state. Then open the outlet manual valve 5 and set the temperature of the flexible heating sleeve 2 through the PLC controller 8. Monitor the pressure of the gas volatilized from the source bottle 1 through the precursor source pressure gauge 15 and compare this pressure with the theoretical saturated vapor pressure of the precursor source 3. If this pressure is slightly greater than the theoretical saturated vapor pressure, the heating temperature is appropriate and the next step can be carried out. If this pressure is less than the theoretical saturated vapor pressure, the heating temperature of the flexible heating sleeve 2 needs to be increased through the PLC controller 8 to finally determine the appropriate heating temperature.

[0019] It should be noted that during the process of setting the temperature, the temperature needs to be gradually increased from low to high to avoid exceeding the appropriate heating temperature. After determining the appropriate heating temperature, open the intake manual valve 4, observe the pressure of the gas storage pressure gauge 10, and set the flow rate of the mass flow controller 11, the opening time of the intake pneumatic valve 7, the opening time of the bypass pneumatic valve 14, and the opening time of the outlet pneumatic valve 17 through the PLC controller 8 to adjust the pressure of the gas storage pressure gauge 10 to an appropriate value, and then a preliminary experiment is carried out.

[0020] During the pre-experiment, observe the data monitored by the gas analyzer 12, and set the opening time of the outlet pneumatic valve 17 through the PLC controller 8, so as to adjust the ratio of the carrier gas to the precursor source vapor in the gas volatilized from the source bottle 1.

[0021] After ensuring that there are no problems with the process, set other parameters through the PLC controller 8, such as the heating temperature of the pipeline, valve, and reaction chamber, to prevent the precursor source 3 from condensing in the system, and then conduct the formal experiment.

[0022] The beneficial effects of this application are as follows:

[0023] The atomic layer deposition gas supply system for low saturated vapor pressure precursor sources proposed by the present invention can accurately control the amount of gas entering the carrier gas-assisted precursor source bottle by adding a mass flow controller, an auxiliary gas storage tank, and a bypass extraction pneumatic valve, and combining them with the original inlet pneumatic valve, ensuring the stability of the gas volume in the precursor source bottle; further, this application adds a pressure gauge at the source outlet of the carrier gas-assisted precursor source bottle to monitor the internal pressure of the source bottle in real time, and determines the appropriate heating temperature of the source bottle by observing the pressure; further, the solution of this application adds a gas analyzer at the source outlet of the carrier gas-assisted precursor source bottle to monitor the composition of the source gas in real time. By analyzing the gas composition through the analyzer, the content of the auxiliary gas and the precursor source vapor in the source gas can be obtained, which is convenient for judging whether the source amount is sufficient, so as to determine the next operation in the deposition reaction process. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] Figure 1 It is a schematic diagram of the composition of the atomic layer deposition gas supply system for low saturated vapor pressure precursor sources provided by an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of the connection components of the PLC controller in the atomic layer deposition gas supply system for low saturated vapor pressure precursor sources provided by an embodiment of the present invention;

[0027] Figure 3 It is a flowchart of the atomic layer deposition gas supply method for low saturated vapor pressure precursor sources provided by an embodiment of the present invention;

[0028] Among them, 1. Carrier gas-assisted precursor source bottle, 2. Flexible heating jacket, 3. Precursor source, 4. Inlet manual valve, 5. Outlet manual valve, 6. Reaction chamber, 7. Inlet pneumatic valve, 8. PLC controller, 9. Auxiliary gas storage tank, 10. Storage pressure gauge, 11. Mass flow controller, 12. Carrier gas cylinder, 13. Vacuum pump, 14. Side extraction pneumatic valve, 15. Precursor source pressure gauge, 16. Gas analyzer, 17. Outlet pneumatic valve. Detailed implementation mode

[0029] To make the objectives, technical solutions and advantages of the present invention clearer, the following will further describe in detail the embodiments of the present invention with reference to the accompanying drawings.

[0030] Embodiment 1

[0031] This embodiment provides an atomic layer deposition gas supply system for a precursor source with a low saturated vapor pressure. The system is provided with a heating device and a carrier gas device for a precursor source with a relatively low saturated vapor pressure, and also provided with a gas analyzer and a pressure gauge. Based on the air pressure value and gas composition in the precursor source bottle, the PLC controller precisely controls the heating power of the heating device and the opening and closing time of the inlet pneumatic valve of the carrier gas device, so as to achieve stable gas supply for the precursor source with a low saturated vapor pressure. Considering the temperature tolerance of the manual valve on the precursor source bottle, the system determines an appropriate heating temperature on the premise of ensuring stable gas supply.

[0032] As Figure 1 and Figure 2 shown, the gas supply system includes a precursor source bottle 1, a flexible heating jacket 2, an inlet manual valve 4, an outlet manual valve 5, an inlet pneumatic valve 7, a PLC controller 8, an auxiliary gas storage tank 9, a storage pressure gauge 10, a mass flow controller 11, a carrier gas cylinder 12, a vacuum pump 13, a side extraction pneumatic valve 14, a precursor source pressure gauge 15, a gas analyzer 16, and an outlet pneumatic valve 17.

[0033] Among them, a flexible heating jacket 2 is provided outside the precursor source bottle 1 (hereinafter referred to as source bottle 1) for heating the source bottle 1 and indirectly heating the precursor source 3 inside the source bottle 1 by means of heat conduction. An air inlet and an air outlet are provided above the source bottle 1. The air inlet is connected to an auxiliary gas storage tank 9 storing auxiliary gas through an inlet pipe, and the air outlet is connected to a reaction chamber 6 of an atomic layer deposition device through an outlet pipe. The inlet pipe extends to the bottom of the source bottle 1, and the outlet pipe is located at the top of the source bottle 1. An inlet manual valve 4 is provided at the air inlet of the source bottle 1, and an outlet manual valve 5 is provided at the air outlet. The inlet manual valve 4 and the outlet manual valve 5 are used to achieve sealing during the installation and disassembly of the source bottle 1, preventing the precursor source 3 from deteriorating after contacting air. The inlet pipe is used to transport auxiliary gas into the source bottle 1, and the outlet pipe is used to transport a mixture of auxiliary gas and precursor source 3 to the reaction chamber 6. An inlet pneumatic valve 7 is provided outside the inlet manual valve 4. The inlet pneumatic valve 7 is connected to a PLC controller 8, and the opening time of the inlet pneumatic valve 7 is precisely controlled by the PLC controller 8, so as to precisely control the amount of auxiliary gas entering the source bottle 1 by precisely controlling the time when the auxiliary gas enters the source bottle 1.

[0034] A gas storage pressure gauge 10 is provided on the auxiliary gas storage tank 9, and a mass flow controller 11 is provided at the rear end. The rear end of the mass flow controller is connected to a carrier gas cylinder 12. A bypass pumping pipeline connected to a vacuum pump 13 is provided between the auxiliary gas storage tank 9 and the inlet pneumatic valve 7. A bypass pumping pneumatic valve 14 is provided on the bypass pumping pipeline. Both the gas storage pressure gauge 10 and the bypass pumping pneumatic valve 14 are connected to the PLC controller 8. The flow rate of the mass flow controller 11 and the opening time of the bypass pumping pneumatic valve 14 can be set through the PLC controller 8, so as to precisely control the amount of auxiliary gas stored in the auxiliary gas storage tank 9.

[0035] A precursor source pressure gauge 15 and a gas analyzer 16 are provided on the pipeline between the outlet manual valve 5 of the source bottle 1 and the outlet pneumatic valve 17. Both the precursor source pressure gauge 15 and the gas analyzer 16 are connected to the PLC controller 8. In the state where the outlet manual valve 5 is opened, the PLC controller 8 can real-time monitor the gas pressure in the source bottle 1 through the precursor source pressure gauge 15, and the gas analyzer 16 can real-time monitor the gas components volatilized from the source bottle 1, mainly used to determine the content of precursor source vapor and auxiliary gas in the mixed gas volatilized from the source bottle 1. The PLC controller correspondingly adjusts the heating temperature of the flexible heating jacket 2 and the intake amount of the auxiliary gas according to the pressure feedback by the precursor source pressure gauge 15 and the proportion of the precursor source vapor content in the mixed gas volatilized from the inside of the source bottle 1 feedback by the gas analyzer 16.

[0036] An outlet pneumatic valve 17 is provided outside the gas analyzer 16. The outlet pneumatic valve 17 is connected to the PLC controller 8, and the opening time of the outlet pneumatic valve 17 can be precisely controlled by the PLC controller 8, so as to precisely control the amount of the mixed gas entering the reaction chamber 6.

[0037] Example Two

[0038] This embodiment provides an atomic layer deposition gas supply method for a low saturation vapor pressure precursor source, which is implemented based on the gas supply system provided in Example One. As Figure 3 shown, this method includes:

[0039] Step 1: Close the inlet and outlet pneumatic valves and the inlet manual valve, and open the outlet manual valve.

[0040] Step 2: Use the heating device to heat the precursor source in the carrier gas-assisted precursor source bottle. The heating temperature is set to T1, and T1 is set according to the empirical value of the specific precursor source, and T1 < T0, where T0 is the maximum temperature that the inlet and outlet manual valves can withstand.

[0041] Step 3: Obtain the value P1 of the precursor source pressure gauge and compare it with the theoretical value P of the saturation vapor pressure corresponding to the temperature T1. If P1 < P, then increase the heating temperature of the heating device until the value of the precursor source pressure gauge is equal to or greater than the theoretical value of the saturation vapor pressure corresponding to the increased temperature. At this time, the temperature is recorded as T2, T2 ≤ T0, and T2 is determined as the final heating temperature.

[0042] If when the heating temperature of the heating device is increased to T0, the value of the precursor source pressure gauge is still less than its corresponding theoretical value of the saturation vapor pressure, then T0 is determined as the final heating temperature.

[0043] Step 4: After determining the final heating temperature, open the inlet manual valve and the inlet pneumatic valve of the carrier gas-assisted precursor source bottle to introduce carrier gas into the carrier gas-assisted precursor source bottle; at the same time, open the outlet pneumatic valve to supply gas to the reaction chamber.

[0044] Step 5: During the gas supply process, analyze the gas composition in the carrier gas-assisted precursor source bottle through a gas analyzer. If the precursor content ratio is lower than a preset threshold, then control the PLC controller to reduce the opening time of the inlet pneumatic valve or close the inlet pneumatic valve.

[0045] The introduction of this gas supply method in further combination with the actual deposition process is as follows:

[0046] Refer to Figure 3 , before the deposition experiment starts, first open the outlet manual valve 5, adjust the temperature of the flexible heating sleeve 2, monitor the gas pressure volatilized from the source bottle 1 through the precursor source pressure gauge 15, and compare it with the theoretical saturation vapor pressure at the corresponding temperature of the specific precursor source 3 to determine the appropriate heating temperature. The specific determination process is as follows:

[0047] First, set the heating temperature of the flexible heating sleeve 2 to T1 according to the empirical value. T1 should be lower than the maximum temperature that the inlet and outlet manual valve can withstand. Obtain the value of the precursor source pressure gauge 15 at this temperature. If the pressure monitored by the precursor source pressure gauge 15 is lower than the theoretical saturated vapor pressure of the precursor source 3, the PLC controller 8 needs to further increase the heating temperature of the flexible heating sleeve 2 until the pressure monitored by the precursor source pressure gauge 15 reaches the theoretical saturated vapor pressure corresponding to the temperature of the precursor source 3, and finally determine the appropriate heating temperature. It should be noted that if the temperature rises to the maximum temperature T0 that the inlet and outlet manual valve can withstand and the gas pressure volatilized from the source bottle 1 is still lower than the theoretical saturated vapor pressure corresponding to this temperature, the heating temperature will no longer be increased, and the carrier gas is used to accelerate the volatilization degree of the precursor source at this heating temperature. In addition, during the process of gradually increasing the heating temperature, the temperature needs to be set step by step from low to high to avoid exceeding the appropriate heating temperature.

[0048] After determining the appropriate heating temperature, the flow rate of the mass flow controller 10 can be set through the PLC controller 8, and the pressure value of the gas storage pressure gauge 10 can be observed. Usually, the specific flow rate value can be determined according to experience, and the relationship line between the flow rate and the pressure value in the auxiliary gas storage tank can be determined according to experience; during the process of introducing the carrier gas, the pressure value of the gas storage pressure gauge 10 can be compared with the preset pressure range in the auxiliary gas storage tank. If it is higher than the maximum value of the pressure range, the flow rate of the mass flow controller 10 can be reduced through the PLC controller 8, and the opening time of the bypass pneumatic valve 14 can be set through the PLC controller so that the excess gas is pumped away by the vacuum pump 13; if the pressure value of the gas storage pressure gauge 10 is lower than the minimum value of the pressure range, the flow rate of the mass flow controller 10 can be increased through the PLC controller 8, and finally the appropriate auxiliary gas storage volume can be determined.

[0049] After determining the appropriate auxiliary gas storage volume, the inlet manual valve 4 can be opened, and the opening times of the inlet pneumatic valve 7 and the outlet pneumatic valve 17 can be set through the PLC controller 8. Observe the pressure value of the precursor source pressure gauge 15 and the gas analysis data of the gas analyzer 16. If the vapor content of the precursor source is not appropriate, the opening times of the inlet pneumatic valve 7 and the outlet pneumatic valve 17 can be adjusted until the vapor content of the precursor source reaches the appropriate value. It should be noted that the opening time of the valve needs to be set step by step from short to long to avoid exceeding the appropriate time length. It should be noted that the appropriate proportion of the precursor source vapor content can be determined according to experiments or set according to empirical values. For example, by comparing the deposition conditions under different precursor source vapor content ratios, the threshold of the precursor source vapor content ratio can be determined.

[0050] After ensuring that the process is problem-free, other conventional parameters can be set through the PLC controller 8, such as the heating temperatures of the pipelines, valves, and reaction chamber, to prevent the precursor source 3 from condensing in the system, and then the formal experiment can be carried out.

[0051] To verify the effectiveness of the atomic layer deposition carrier gas-assisted real-time monitoring system for precursor sources provided in this embodiment, it is verified through two specific deposition processes. One is the process verification of depositing zirconia thin films with zirconium tetrakis(dimethylamido) and water as precursor sources, which is relatively mature in the current process. The other is the process verification of depositing scandium oxide thin films with tris(scandium N,N'-diisopropylformamide)(III) and ozone as precursor sources, which has not been reported currently.

[0052] During the process verification of the zirconia process, since zirconium tetrakis(dimethylamido) is a relatively mature precursor source, the appropriate heating temperature of the source bottle can be determined according to the recommended heating temperature and theoretical saturation vapor pressure provided by the precursor source manufacturer. During the specific experiment, the outlet manual valve 5 is opened, and the temperature of the flexible heating sleeve 2 covering the source bottle 1 is gradually increased from room temperature through the PLC controller 8, and the pressure value of the precursor source pressure gauge 15 is observed and compared with the saturation vapor pressure provided by the precursor source manufacturer. Finally, the appropriate heating temperature is determined to be 40 °C. At this time, the pressure value of the precursor source pressure gauge 15 is 37.0 pascals. Subsequently, the flow rate of the mass flow controller 11 is set to 5 sccm through the PLC controller. The pressure of the gas storage pressure gauge 10 is observed. If the pressure is too high, the opening time of the bypass extraction pneumatic valve 14 is set through the PLC controller 8, and the excess carrier gas is pumped away by the vacuum pump 13. Finally, the appropriate auxiliary gas storage volume is determined. Subsequently, the inlet manual valve 4 is opened, and the opening times of the inlet pneumatic valve 7 and the outlet pneumatic valve 5 are set for a preliminary experiment. During the preliminary experiment, the gas content of the gas analyzer 16 is observed, and it is observed that the vapor content of the precursor source in the mixed gas is reasonable. The heating temperature of the reaction chamber is set to 200 °C, the heating temperature of the pipeline is set to 150 °C, and the heating temperature of the valve is set to 120 °C through the PLC controller 8 to prevent the precursor source vapor from condensing when flowing between the pipeline and the valve. Finally, a formal experiment of 200 cycles is carried out, and the sample obtained is tested using an ellipsometer. The test results show that the thickness of the thin film is about 21 nanometers. After calculation, the deposition rate of the zirconia thin film is about 0.11 nanometers per cycle.

[0053] During the process of verifying the scandium oxide process, since tris(N,N'-diisopropylformamide)scandium(III) is a precursor source that has not been reported before, relevant data of zirconium tetrakis(dimethylamino) were referred to during the process of determining the heating temperature of the precursor source. During the specific experiment, the manual outlet valve 5 was opened, and the temperature of the flexible heating sleeve 2 covering the source bottle 1 was gradually increased from room temperature through the PLC controller 8. The pressure value of the precursor source pressure gauge 15 was observed and compared with the corresponding value of zirconium tetrakis(dimethylamino). When the temperature of the flexible heating sleeve 2 rose to 110 °C, the gas pressure inside the source bottle was about 37.4 pascals. Subsequently, the flow rate of the mass flow controller 11 was set to 5 sccm through the PLC controller 8. When observing the pressure of the gas storage pressure gauge 10, it was found that the pressure was too low, so the flow rate of the mass flow controller 11 was increased to 10 sccm, and the pressure was appropriate. Finally, the appropriate auxiliary gas storage rate was determined. Subsequently, the opening times of the inlet pneumatic valve 7 and the outlet pneumatic valve 5 were set, and the inlet manual valve 4 was opened for a preliminary experiment. During the preliminary experiment, the gas content of the gas analyzer 16 was observed, and it was observed that the content of the precursor source vapor in the mixed gas was relatively low. So, the opening times of the inlet pneumatic valve 7 and the outlet pneumatic valve 5 were adjusted through the PLC controller 8, and the gas analyzer 16 was continuously observed to monitor the content of the precursor source vapor in the mixed gas. During this process, it was found that the content of the precursor source vapor was always relatively low. It was speculated that the reason was that the saturated vapor pressures of tris(N,N'-diisopropylformamide)scandium(III) and zirconium tetrakis(dimethylamino) were different, resulting in the fact that the ideal effect could not be achieved during the preliminary experiment by referring to the relevant values of zirconium tetrakis(dimethylamino). So, the temperature of the flexible heating sleeve 2 covering the source bottle 1 was increased, and the above steps were repeated until the heating temperature rose to 140 °C. The gas analyzer 16 monitored that the content of the precursor source vapor in the mixed gas was reasonable. The heating temperature of the reaction chamber was set to 300 °C, the heating temperature of the pipeline was set to 200 °C, and the heating temperature of the valve was set to 160 °C through the PLC controller 8 to prevent the condensation of the precursor source vapor when flowing between the pipeline and the valve. Finally, a formal experiment of 500 cycles was carried out, and the sample obtained by using an ellipsometer was tested. The test result was that the film thickness was about 27 nanometers. After calculation, the deposition rate of the scandium oxide film was about 0.054 nanometers per cycle.

[0054] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An atomic layer deposition gas supply system for a low saturated vapor pressure precursor source, characterized in that: The system is used to provide a gaseous precursor to a reaction chamber of an atomic layer deposition device, and the system comprises: a carrier gas-assisted precursor source bottle, a heating device, a precursor source pressure gauge, a gas analyzer, an auxiliary gas storage tank, and a PLC controller; Among them, the heating device is used to heat the precursor source in the carrier gas assisted precursor source bottle, the precursor source pressure gauge is used to monitor the pressure in the carrier gas assisted precursor source bottle in real time, the gas analyzer is used to analyze the gas composition in the carrier gas assisted precursor source bottle, the auxiliary gas storage tank is used to store auxiliary gas, and the PLC controller is used to control the heating temperature of the heating device and the amount of auxiliary gas entering the carrier gas assisted precursor source bottle according to the pressure and gas composition in the carrier gas assisted precursor source bottle.

2. The system according to claim 1, characterized in that The carrier gas-assisted precursor source bottle is connected to the reaction chamber of the atomic layer deposition equipment and the auxiliary gas storage tank through gas pipelines respectively; the carrier gas-assisted precursor source bottle is provided with manual inlet and outlet valves; the gas pipeline connecting the carrier gas-assisted precursor source bottle and the reaction chamber of the atomic layer deposition equipment is provided with an outlet pneumatic valve, and the gas analyzer and the precursor source pressure gauge are arranged between the outlet manual valve and the outlet pneumatic valve of the precursor source bottle; the gas pipeline connecting the carrier gas-assisted precursor source bottle and the auxiliary gas storage tank is provided with an inlet pneumatic valve.

3. The system according to claim 2, characterized in that The system is also provided with an auxiliary gas supply device, including a carrier gas bottle, a mass flow controller, a gas storage pressure gauge, a vacuum pump and a side-draw pneumatic valve; wherein the carrier gas bottle is connected to the auxiliary gas storage tank through a gas pipeline, the mass flow controller is arranged on the gas pipeline between the two, and the gas storage pressure gauge is used to detect the pressure in the auxiliary gas storage tank; the vacuum pump is connected to the auxiliary gas storage tank through the side-draw pneumatic valve; the PLC controller controls the mass flow controller and the vacuum pump according to the gas storage pressure gauge value so that the pressure in the auxiliary gas storage tank is within a predetermined range.

4. The system according to claim 3, characterized in that The vacuum pump is also used to evacuate the reaction chamber of the atomic layer deposition equipment.

5. The system according to claim 4, characterized in that The heating device is a flexible heating sleeve, which is arranged outside the carrier gas assisted precursor source bottle.

6. A gas supply method for atomic layer deposition of a low saturated vapor pressure precursor source, characterized in that: The method is implemented based on the atomic layer deposition gas supply system according to any one of claims 1 to 5, and the method comprises: Step 1, close the air inlet and outlet pneumatic valves and the air inlet manual valve, and open the air outlet manual valve; Step 2, using a heating device to heat the precursor source in the carrier gas-assisted precursor source bottle, the heating temperature is set to T1, T1 is set according to the empirical value of the specific precursor source, and T1<T0, T0 is the limit temperature that the manual inlet and outlet valves can withstand; Step 3, obtain the precursor source pressure gauge value P1, and compare it with the theoretical value P of the saturated vapor pressure corresponding to the temperature T1. If P1<P, increase the heating temperature of the heating device until the precursor source pressure gauge value is equal to or greater than the theoretical value of the saturated vapor pressure corresponding to the increased temperature. At this time, the temperature is recorded as T2, T2≤T0, and T2 is determined as the final heating temperature; If the precursor source pressure gauge value is still less than the corresponding saturated vapor pressure theoretical value when the heating temperature of the heating device is increased to T0, T0 is determined as the final heating temperature; Step 4, after determining the final heating temperature, open the manual air inlet valve and the air inlet pneumatic valve of the carrier gas assisted precursor source bottle to introduce carrier gas into the carrier gas assisted precursor source bottle; at the same time, open the air outlet pneumatic valve to supply gas to the reaction chamber; Step 5, during the gas supply process, the gas composition in the carrier gas-assisted precursor source bottle is analyzed by a gas analyzer. If the precursor content ratio is lower than a preset threshold, the PLC controller is used to control the air inlet pneumatic valve to reduce the opening time or close the air inlet pneumatic valve.

7. The method according to claim 6, characterized in that When the system is provided with an auxiliary gas supply device, the method determines the gas flow rate of the mass flow controller according to the pressure in the auxiliary gas storage tank.

8. The method according to claim 7, characterized in that The method controls the gas flow rate so that the pressure in the auxiliary gas storage tank is within a predetermined pressure range, and the predetermined pressure range is set according to an empirical value.

9. The method according to claim 8, characterized in that When the heating temperature of the heating device is increased in step 3, a gradient heating method is adopted.

10. An atomic layer deposition device, characterized in that: The atomic layer deposition equipment comprises the atomic layer deposition gas supply system as described in any one of claims 1-5.

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