Vacuum valve, deposition system and cleaning method thereof

Abstract

The invention discloses a vacuum valve, a deposition system and a cleaning method of the deposition system. The vacuum valve comprises an airflow pipeline, a movable part and a coil. The movable part is movably arranged in the airflow pipeline. The coil is wound around the periphery of the airflow pipeline and used for applying an alternating magnetic field into the airflow pipeline. By means of the mode, blocking generated when the vacuum valve is used can be reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a vacuum valve, a deposition system and a cleaning method thereof. Background Art

[0002] In the related art, the semiconductor thin film deposition system generally includes a reaction device, a negative pressure pump connected to the reaction device, and an exhaust gas treatment device. A vacuum valve can also be set between the reaction device and the negative pressure pump to adjust the suction of the negative pressure pump. During the deposition process, the discharge of exhaust gas will cause the deposition of thin film in the vacuum valve, which is easy to cause the vacuum valve to be blocked. Summary of the invention

[0003] The embodiments of the present application provide a vacuum valve, a deposition system and a cleaning method thereof, which can reduce the blockage of the vacuum valve during use.

[0004] In a first aspect, an embodiment of the present application provides a vacuum valve. The vacuum valve includes an airflow pipeline, a movable part, and a coil. The movable part is movably arranged in the airflow pipeline. The coil is wound around the outer periphery of the airflow pipeline and is used to apply an alternating magnetic field into the airflow pipeline.

[0005] Optionally, the diameter of the coil is 1 mm-3 mm, and the number of turns of the coil is more than 50 turns.

[0006] Optionally, the airflow duct includes a first duct and a second duct extending in different directions, the first duct and the second duct are connected via a connecting duct, the movable part is movably arranged on the connecting duct, and the coil is wound around the first duct, the second duct and the connecting duct.

[0007] Optionally, at least part of the airflow duct is made of insulating material.

[0008] Optionally, the coil is wound around the outer circumference of the airflow duct made of insulating material.

[0009] Optionally, the movable member can move, rotate or swing relative to the airflow duct.

[0010] In a second aspect, an embodiment of the present application provides a deposition system. The deposition system includes a reaction device, a negative pressure pump, and an exhaust gas treatment device connected in series, the deposition system also includes the above-mentioned vacuum valve, the vacuum valve is connected in series between the reaction device and the negative pressure pump, and the deposition system also includes a radio frequency device, which is matched and connected to the coil of the vacuum valve.

[0011] In a third aspect, an embodiment of the present application provides a method for cleaning a deposition system. The method includes turning on a radio frequency power supply and a vacuum valve. A cleaning gas is introduced into the deposition system and passed through the vacuum valve. The cleaning gas includes a carrier gas and a reaction gas.

[0012] Optionally, the carrier gas is argon, and the reaction gas includes nitrogen, oxygen and nitrogen trifluoride.

[0013] Optionally, the argon gas introduction rate is 100-2000 sccm, the nitrogen gas introduction rate is 100-500 sccm, the oxygen gas introduction rate is 1000-7000 sccm, and the nitrogen trifluoride introduction rate is 100-2000 sccm.

[0014] The beneficial effect of the present application is that, different from the prior art, a coil is arranged on the periphery of the airflow pipe, so that when the radio frequency current flows through the coil, an alternating magnetic field is generated inside the vacuum valve, and the alternating magnetic field can generate an electric field sufficient to ionize the clean gas through inductive coupling. After the clean gas is ionized, the thin film deposited inside the vacuum valve can be etched, thereby reducing the blockage caused by the thin film inside the vacuum valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the deposition system of the present application;

[0016] Figure 2 It is a schematic diagram of the partial structure of the vacuum valve of the present application;

[0017] Figure 3 It is a structural schematic diagram of another embodiment of the vacuum valve of the present application;

[0018] Figure 4 It is a schematic diagram of the cleaning method of the deposition system of the present application;

[0019] Figure 5 is a schematic diagram of a vacuum valve before cleaning in one embodiment of the present application;

[0020] Figure 6 yes Figure 5 Schematic diagram of the effect of vacuum valve cleaning. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] The present application provides a deposition system 1, which is intended to improve the efficiency and quality of the thin film deposition process, while reducing equipment maintenance time and cost. The deposition system 1 can apply different deposition technologies, such as chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and is not specifically limited here. Figure 1 As shown, the deposition system 1 includes a reaction device 10, a negative pressure pump 30 and an exhaust gas treatment device 40 connected in series. The reaction device 10 has a reaction chamber, and different process gases can be introduced into the reaction chamber. The interior of the reaction chamber is where the deposition process occurs, which is usually a high vacuum environment to ensure the purity of the deposition process. Under the action of the radio frequency field, the process gas can be ionized and react with the surface of the substrate to achieve the purpose of depositing a thin film. Clean gas can also be introduced into the reaction chamber to clean and purge the reaction chamber.

[0023] The negative pressure pump 30 can provide negative pressure. On the one hand, the negative pressure pump 30 can pump different types of process gases. On the other hand, the negative pressure pump 30 can also pump out the gas in the reaction chamber to maintain a sufficient vacuum degree.

[0024] The tail gas treatment device 40 can treat the sucked tail gas, so as to recover resources and treat it harmlessly. The tail gas treatment device may include a filtering system, a cold trap or a heating system, etc., which are not specifically limited here.

[0025] The deposition system 1 may further include a gas delivery system, which may include, for example, a gas source, a mass flow controller, a pneumatic valve, and a pipeline, for precisely controlling the flow and ratio of the reaction gas.

[0026] The deposition system 1 further includes a vacuum valve 20, which is connected in series between the reaction device 10 and the negative pressure pump 30. The vacuum valve 20 can move the movable part 22 by driving operation, thereby controlling the opening or closing of the channel to achieve accurate regulation of the gas flow. The vacuum valve 20 can adjust the on-off of the passage between the reaction device 10 and the negative pressure pump 30, and can also adjust the suction force of the negative pressure pump 30 by changing the cross-section of the passage.

[0027] The deposition system 1 also includes a radio frequency device (not shown), which is matched and connected with the coil 23 of the vacuum valve 20. After the radio frequency device is connected to the coil 23, a radio frequency current can be applied to the coil 23. The coil 23 can generate an alternating magnetic field under the action of the radio frequency current, and the alternating magnetic field can generate an alternating electric field in the surrounding space after inductive coupling. Under the action of the alternating electric field, the clean gas can be ionized. In an inductively coupled plasma (ICP), the maintenance of the plasma depends on the energy continuously provided by the induction coil. The alternating magnetic field generated by the induction coil excites an induced current in the plasma. The resistance of these currents is very small, so the current is very large, which can generate high temperature, further heat and ionize the gas, and form a stable plasma torch. . The ionized clean gas can etch the thin film in the vacuum valve 20 to reduce the blockage caused by the thin film. The structure of the vacuum valve 20 is introduced as an example below.

[0028] Combination Figure 2 and Figure 3 , an embodiment of the present application provides a vacuum valve 20. The vacuum valve 20 includes an airflow duct 21, a movable part 22 and a coil 23. The vacuum valve 20 can be a butterfly valve, a ball valve, an angle valve, a diaphragm valve, a needle valve, a plug valve or an electromagnetic vacuum valve, etc. The airflow duct 21 can allow clean gas to flow through. The movable part 22 is movably arranged in the airflow duct 21. The movable part 22 can block the airflow duct 21 or limit the flow of the airflow duct 21 through movement. The coil 23 is wound around the outer periphery of the airflow duct 21, and is used to apply an alternating magnetic field to the airflow duct 21. According to the type of the vacuum valve 20, the type of the movable part 22 can be a valve plate, a valve ball, a valve stem, a diaphragm, a needle-shaped component or a flat gate, etc.

[0029] By arranging the coil 23 on the periphery of the gas flow pipe 21, an alternating magnetic field is generated inside the vacuum valve 20 when the radio frequency current flows through the coil 23. The alternating magnetic field can generate an electric field sufficient to ionize the clean gas through inductive coupling. After the clean gas is ionized, it can etch the thin film deposited inside the vacuum valve 20, thereby reducing the blockage caused by the thin film inside the vacuum valve 20.

[0030] In some embodiments, the movable member 22 can move, rotate or swing relative to the airflow duct 21. The movable member 22 can block the airflow duct 21 or limit the flow of the airflow duct 21 by moving, rotating or swinging relative to the airflow duct 21. In other words, the vacuum valve 20 can be a gate valve, a swing valve or a butterfly valve.

[0031] In some embodiments, in order to generate a sufficient alternating magnetic field under radio frequency current, the diameter of the coil 23 is 1 mm-3 mm, and the number of turns of the coil 23 is more than 50 turns.

[0032] In some embodiments, in combination Figure 2The airflow pipe 21 includes a first pipe 211 and a second pipe 212 with different extension directions. The first pipe 211 and the second pipe 212 are connected by a connecting pipe 213. The movable part 22 is movably arranged in the connecting pipe 213, and the coil 23 is wound around the first pipe 211, the second pipe 212 and the connecting pipe 213. The first pipe 211 and the second pipe 212 have different extension directions, which can enable the vacuum valve 20 to have the function of changing the airflow direction. The movable part 22 cooperates with the connecting pipe 213 to achieve the blocking of the airflow pipe 21 or limit the flow of the airflow pipe 21. The coil 23 can apply an alternating magnetic field to the inside of the airflow pipe 21 by being wound around the first pipe 211, the second pipe 212 and the connecting pipe 213. Among them, the coils 23 corresponding to the first pipe 211, the second pipe 212 and the connecting pipe 213 can be the same group of coils 23. The first pipe 211, the second pipe 212 and the connecting pipe 213 can also correspond to different groups of coils 23, and the coils 23 of different groups can have the same or different diameters and turns.

[0033] In some embodiments, the coil 23 can be wound around the outer periphery of the airflow duct 21 in a spiral winding manner. In other embodiments, a plurality of coils 23 can be arranged at intervals on the outer periphery of the airflow duct 21, wherein each coil 23 can be connected to a power source separately to generate a magnetic field separately. The magnetic pole direction of each coil 23 can be arranged along the radial direction of the airflow duct 21. Multiple coils 23 can cooperate to generate an alternating magnetic field in the airflow duct 21.

[0034] In some embodiments, the airflow duct 21 is made of an insulating material. The insulating material may be, for example, ceramic or quartz. The airflow duct 21 may also be made by depositing or coating an insulating material on the outer surface of a traditional metal material, so that the airflow duct 21 has sufficient strength while also being able to meet the process requirements proposed in the embodiments of the present application. Among them, in some embodiments, the portion of the airflow duct 21 corresponding to the movable part 22 is made of an insulating material. In addition, the coil 23 is arranged on the periphery of the airflow duct 21 made of an insulating material. In this way, the other parts of the airflow duct 21 can still use the metal material in the vacuum valve 20 technology, which can meet the requirements of the ionized clean gas in the embodiments of the present application, and can also improve the overall strength of the airflow duct 21.

[0035] In other embodiments, the entire airflow duct 21 may be made of insulating material. Further, the vacuum valve 20 further includes a main duct, which is made of metal material and connected to either end of the airflow duct 21. Alternatively, the main duct is connected to both ends of the airflow duct 21 respectively.

[0036] In some embodiments, the airflow duct 21 may also be provided with a cleaning inlet and a cleaning outlet, and the cleaning gas may also be selected to flow through the airflow duct from the cleaning inlet and the cleaning outlet of the airflow duct 21. In the deposition system 1 provided in the embodiment of the present application, the cleaning of the vacuum valve 20 requires the injection of cleaning gas. In the case where the reaction device 10 and the vacuum valve 20 need to be cleaned at the same time, the cleaning of the reaction device 10 and the cleaning of the vacuum valve 20 can be completed simultaneously by starting the entire deposition system 1. However, if a separate cleaning vacuum valve 20 is required, starting the entire deposition system 1 will cause a waste of resources and time. By setting a cleaning inlet and a cleaning outlet on the vacuum valve 20, when the deposition system 1 is not started, the cleaning gas can be introduced into the vacuum valve 20 through the cleaning inlet and the cleaning outlet, and then the coil 23 is individually controlled to generate a magnetic field to clean the vacuum valve 20.

[0037] Optionally, the air flow duct 21 may not be provided with a cleaning outlet, but the gas after cleaning the vacuum valve 20 is processed by the negative pressure pump 30 and the tail gas treatment device 40 of the above embodiment.

[0038] Combination Figure 4 The present application also provides a method for cleaning the deposition system 1. The method includes:

[0039] S10: Turn on the radio frequency power supply and the vacuum valve 20.

[0040] When the deposition system 1 is in a non-cleaning period, the deposition work is performed in the reaction device 10. In different deposition processes, the RF power supply and the vacuum valve 20 may be in an open state or in a closed state. After the deposition system 1 enters the cleaning period, the RF power supply and the vacuum valve 20 are opened to prepare for cleaning the deposition system 1.

[0041] S20: introducing a cleaning gas into the deposition system 1 and passing the cleaning gas through the vacuum valve 20. The cleaning gas includes a carrier gas and a reaction gas.

[0042] The clean gas can be discharged through the vacuum valve 20. After the RF power supply and the vacuum valve 20 are turned on, an alternating magnetic field can be generated in the airflow pipe 21 of the vacuum valve 20 under the action of the coil 23. The magnetic field will generate an electric field that changes with time through inductive coupling. The inductively coupled electric field can accelerate electrons and produce ionized collisions, and a high-density plasma will be generated when the clean gas passes through. Under the action of the plasma, the thin film deposited in the vacuum valve 20 can be etched, thereby cleaning the vacuum valve 20 and preventing blockage.

[0043] In some embodiments, the carrier gas is argon, and the reaction gas includes nitrogen, oxygen, and nitrogen trifluoride. The film deposited on the vacuum valve 20 is a carbon film. After the nitrogen, oxygen, and nitrogen trifluoride are ionized, they can react with the carbon film. After the carbon film remaining in the vacuum valve 20 is etched, valve blockage caused by the carbon film can be prevented.

[0044] In some embodiments, the argon gas is introduced at a rate of 100-2000 sccm, such as 500 sccm, 800 sccm, 1300 sccm or 1600 sccm. The nitrogen gas is introduced at a rate of 100-500 sccm, such as 160 sccm, 230 sccm, 340 sccm or 450 sccm. The oxygen gas is introduced at a rate of 1000-7000 sccm, such as 2300 sccm, 3400 sccm, 4500 sccm or 5600 sccm. The nitrogen trifluoride is introduced at a rate of 100-2000 sccm, such as 500 sccm, 800 sccm, 1300 sccm or 1600 sccm.

[0045] Combination Figure 4 and Figure 5 , Figure 4 This is the effect picture of the vacuum valve 20 before cleaning. Figure 5 2 is a diagram showing the effect of cleaning the vacuum valve 20. In one embodiment, the inventor of the present application cleaned the surface of a sample slice placed at the vacuum valve 20 under the conditions of pressure control at 2 torr, oxygen flow rate at 3000 sccm, and temperature at 180°C, and found that the cleaning efficiency under such conditions is greater than (Angstrom / second). It is proved that in the above embodiment of the present application, the vacuum valve 20 can be effectively cleaned.

[0046] In summary, through this method, the present solution not only improves the cleaning efficiency of the vacuum valve 20, but also reduces the equipment maintenance and downtime caused by carbon film blockage, thereby significantly improving the stability and production efficiency of the semiconductor manufacturing process. In addition, in the part corresponding to the airflow duct 21 and the movable part 22, the use of insulating materials such as ceramic rings instead of traditional metal rings can also improve the corrosion resistance and high temperature resistance of the vacuum valve 20, further extending the service life of the equipment. The embodiment of the present application provides an efficient and reliable method for cleaning and maintaining the vacuum valve 20 for the semiconductor manufacturing industry.

[0047] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A vacuum valve, characterized in that: include: Airflow ducts; A movable part, wherein the movable part is movably arranged in the air flow duct; The coil is wound around at least a portion of the outer circumference of the airflow duct and is used to apply an alternating magnetic field into the airflow duct.

2. The vacuum valve according to claim 1, characterized in that: The diameter of the coil is 1 mm-3 mm, and the number of turns of the coil is more than 50 turns.

3. The vacuum valve according to claim 1, characterized in that: The airflow duct includes a first duct and a second duct extending in different directions. The first duct and the second duct are connected via a connecting duct. The movable member is movably arranged on the connecting duct. The coil is wound around the first duct, the second duct and the connecting duct.

4. The vacuum valve according to any one of claims 1 to 3, characterized in that: At least a portion of the airflow duct is made of insulating material.

5. The vacuum valve according to claim 4, characterized in that: The coil is wound around the outer circumference of the airflow duct made of insulating material.

6. The vacuum valve according to claim 1, characterized in that: The movable part can move, rotate or swing relative to the air flow duct.

7. A deposition system, characterized in that: include: A reaction device, a negative pressure pump and an exhaust gas treatment device are connected in series in sequence, and the deposition system also includes a vacuum valve as described in any one of claims 1 to 6, and the vacuum valve is connected in series between the reaction device and the negative pressure pump. The deposition system also includes a radio frequency device, and the radio frequency device is matched and connected with the coil of the vacuum valve.

8. A method for cleaning a deposition system, characterized in that: include Turn on the RF power supply and vacuum valve; Introducing a clean gas into the deposition system and passing it through a vacuum valve; The cleaning gas includes a carrier gas and a reaction gas.

9. The method according to claim 8, characterized in that: The carrier gas is argon, and the reaction gas includes nitrogen, oxygen and nitrogen trifluoride.

10. The method according to claim 9, characterized in that: The argon gas introduction rate is 100-2000sccm, the nitrogen gas introduction rate is 100-500sccm, the oxygen gas introduction rate is 1000-7000sccm, and the nitrogen trifluoride introduction rate is 100-2000sccm.

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