JP2019012812A - Exhaust facility system - Google Patents

Abstract

To provide an exhaust facility in which the residual amount of by-products in an exhaust facility is reduced to further improve the operation rate of the exhaust facility.SOLUTION: In order to evacuate a chamber 14 of a semiconductor manufacturing apparatus 12, a vacuum pump 10 is installed downstream of the chamber 14. A gas supply device 18 is connected to the vacuum pump 10 and supplies a gas containing hydrogen halide and nitrogen to the vacuum pump 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exhaust system system.

  In a manufacturing apparatus that manufactures semiconductor devices, liquid crystal panels, LEDs, solar cells, and the like, various processes such as a film forming process and an etching process are performed by introducing a process gas into a process chamber evacuated to a vacuum. In order to exhaust the inside of the chamber of the manufacturing apparatus, an exhaust system facility is installed downstream of the chamber of the manufacturing apparatus. The exhaust system equipment includes a vacuum pump, an abatement device, piping for connecting them to each other, piping for connecting the chamber and the vacuum pump or the abatement device, and the like.

  The vacuum pump evacuates a process chamber that performs various processes such as a film forming process and an etching process. Process gas contains silane-based gases (SiH4, TEOS, etc.), etc., and adversely affects the human body and adversely affects the global environment such as causing global warming. . Therefore, these exhaust gases are detoxified by a detoxifying device installed on the downstream side of the vacuum pump and then released into the atmosphere.

  The vacuum pump exhausts the gas inside the chamber in order to maintain the chamber of the semiconductor manufacturing apparatus in a vacuum state. Since the gas for film formation supplied to the chamber contains gas that generates by-products, by-products flow into the vacuum pump together with the exhaust gas, or by-products are generated inside the pump. Occurs. A by-product brought into the vacuum pump or a by-product generated inside the pump is sandwiched between gaps between the rotors of the vacuum pump or between the rotor and the casing housing the rotor. For this reason, a by-product inhibits the normal rotation of the vacuum pump.

  The gas which produces | generates a by-product is gas required for the wafer film-forming process (manufacturing process) etc. which are the objectives of a semiconductor manufacturing apparatus. The function of the vacuum pump is based on the premise that all the gas supplied to the manufacturing apparatus is exhausted, and generation of by-products cannot be avoided. A user of a semiconductor manufacturing apparatus desires that the vacuum pump does not stop when the semiconductor manufacturing apparatus manufactures a product (during a film forming process). This is because if the vacuum pump is stopped during the film forming process, all the products being manufactured must be discarded, which causes undesirable costs. In addition, the user wants to extend the continuous operation time of the vacuum pump so as not to stop the vacuum pump until the pump maintenance time (for example, the periodic replacement time of the vacuum pump) in order to improve the operating rate of the manufacturing apparatus. Yes.

  In the technology described in Japanese Patent No. 5562144, in order to prevent the by-product of the process gas from accumulating before the rotation of the rotor is obstructed, it is proposed to perform a product countermeasure operation for scraping off the deposit. doing.

  As another preventive measure, the generation of by-products is suppressed or the solidification of the by-products is prevented by lowering or increasing the temperature of the pump. Specifically, products are reduced by using compression heat generated by the vacuum pump, a heater installed in the vacuum pump, and cooling water circulating outside the vacuum pump. In this case, the temperature of the pump is reduced or increased in consideration of the temperature unique to the product (reaction temperature or sublimation temperature). In the above prior art, by-products that cannot be solidified by lowering or increasing the temperature of the pump remain, and it is desired to further reduce the residual amount and improve the operating rate of the vacuum pump and the like. ing.

Patent No.5562144

  One aspect of the present invention is to solve such problems, and the object is to reduce the amount of by-products accumulated on the rotor or casing surface of the vacuum pump and to operate the exhaust system equipment. It is to provide an exhaust system facility in which the rate is further improved.

  In order to solve the above problems, in the first embodiment, in order to exhaust the inside of the chamber of the manufacturing apparatus, an exhaust system facility that can be installed downstream of the chamber and a hydrogen halide connected to the exhaust system facility. And a gas supply device capable of supplying a gas containing at least one of fluorine, chlorine, chlorine trifluoride, and fluorine radicals to the exhaust system facility. Yes.

In the present embodiment, silicon dioxide (SiO ₂ ) occupying most of the by-products remaining in the exhaust system facility is decomposed with a gas containing at least one of hydrogen halide, fluorine, and chlorine trifluoride. To do. For example, the following reaction is caused using hydrogen fluoride (HF).
SiO ₂ + 4HF → SiF ₄ + 2H ₂ O
The generated silicon fluoride (SiF ₄ ) has a low boiling point and sublimates at −95.5 ° C., so that it can be easily removed as a gas at room temperature. Therefore, the residual amount of by-products in the exhaust system facility can be reduced, and the operating rate of the exhaust system facility can be further improved.

  According to the experiment, most of the silicon dioxide remaining in the vacuum pump, which is one of the exhaust system facilities, was converted to silicon fluoride by hydrogen fluoride and could be removed from the vacuum pump. Here, the hydrogen halide is a compound of hydrogen and halogen (group 17 element of the periodic table, that is, fluorine F, chlorine Cl, bromine Br, iodine I, astatine At). The general formula of hydrogen halide is HX (X is halogen).

  The exhaust system system includes a vacuum pump, a gas supply device, an abatement device, piping for connecting these to each other, piping for connecting the chamber and the vacuum pump or the abatement device, and the like. Combinations of vacuum pump, gas supply device and abatement device include (1) gas supply device + vacuum pump + abatement device, (2) gas supply device + vacuum pump, (3) gas supply device + abatement device, etc. There is.

  Removal of a by-product by cleaning a vacuum pump using hydrogen halide gas or the like is to remove, for example, a product that inhibits rotation of the rotor by a chemical reaction with the cleaning gas. The removal of the by-product is not “reducing or suppressing the production of the by-product” but “removal of the produced by-product”. The removal of the by-product is to secure a clearance portion (that is, a gap between the pump body and the rotating body) by removing the by-product. If the clearance portion can be secured, it is not necessary to decompose or remove all by-products. There is basically no need for maintenance of the auxiliary equipment related to the exhaust system facility or the exhaust system piping.

  In a second aspect, the exhaust system facility includes a connection portion with the manufacturing apparatus, and the gas supply device is connected to the exhaust system facility at the connection portion. The configuration of the exhaust system equipment system is adopted.

In the third mode, the gas supply device has a cylinder filled with at least one of hydrogen halide, fluorine, chlorine, and chlorine trifluoride. The exhaust system according to the first or second mode is characterized in that The equipment system is adopted.

  In the fourth embodiment, the exhaust system equipment system according to any one of the first to third embodiments, which has a gas temperature control device for controlling the temperature of the gas, is employed.

  In the fifth embodiment, the gas temperature control device adopts a configuration of an exhaust system facility system according to a fourth embodiment, which controls the temperature of the gas in a range of 50 ° C. to 250 ° C.

  In the sixth aspect, there are a plurality of exhaust system facilities, and the gas is supplied from one gas supply device to the plurality of exhaust system facilities. It adopts the configuration of one exhaust system facility system.

  In a seventh aspect, the exhaust system facility system includes a water supply device that supplies water, which is gas or mist, to the gas, and a mixture of the water and the gas is supplied to the exhaust system facility. The exhaust system equipment system according to any one of the first to sixth aspects is employed. Here, mist refers to liquid fine particles dispersed in a gas, and is also referred to as mist / droplet.

  In an eighth aspect, the exhaust system facility system includes a control unit that controls supply of the gas from the gas supply device to the exhaust system facility, and the control unit outputs the manufacturing output by the manufacturing apparatus. The exhaust system system according to any one of the first to seventh embodiments is characterized in that the control is performed based on a state signal indicating an operation state of the apparatus.

In a ninth aspect, the exhaust system facility system includes a control unit that controls supply of the gas from the gas supply device to the exhaust system facility.
For the abatement device installed downstream of the exhaust system facility and detoxifying the exhaust gas discharged from the exhaust system facility, the manufacturing apparatus outputs a status signal indicating the operating state of the manufacturing apparatus And
The control unit receives the status signal from the abatement apparatus, and performs the control based on the received status signal, and the exhaust system equipment according to any one of the first to seventh aspects, The system is adopted.

  In a tenth aspect, the exhaust system facility system includes a control unit that controls supply of the gas from the gas supply device to the exhaust system facility, and the control unit outputs the exhaust system facility. The exhaust system equipment system according to any one of the first to seventh embodiments is characterized in that the control is performed based on a state signal indicating an operation state of the exhaust system equipment.

  In an eleventh aspect, any one of the first to eighth and tenth aspects is characterized in that the exhaust system facility includes a detoxification device that treats the exhaust gas discharged from the chamber and renders it harmless. It has a configuration of two exhaust system systems.

  In a twelfth aspect, the exhaust system facility has a configuration of any one exhaust system facility system according to the first to eleventh aspects, including a vacuum pump.

  Removal of by-products by cleaning with hydrogen halide gas, etc., removes by-products in the exhaust pipe that connects the vacuum pump and the abatement device provided downstream of the vacuum pump in addition to the vacuum pump. It can also be applied to. This eliminates the need for piping maintenance for preventing the back pressure of the vacuum pump from increasing, or reduces the maintenance frequency.

  The removal of the product by cleaning using hydrogen halide gas or the like can be applied not only to the vacuum pump but also to the removal of by-products inside the detoxifying device installed (downstream) on the exhaust side of the vacuum pump. This eliminates the need for maintenance for removing by-products attached to the components of the abatement apparatus, or reduces the maintenance frequency.

  In a thirteenth aspect, the manufacturing apparatus is a semiconductor manufacturing apparatus for manufacturing a semiconductor, and employs a configuration of any one exhaust system facility system according to the first to twelfth aspects. .

  In a fourteenth aspect, the gas supply apparatus includes a plasma generator, and the fluorine radical is generated by the plasma generator, and the exhaust system according to any one of the first to thirteenth aspects The equipment system is adopted.

In the embodiment using fluorine radicals, silicon dioxide (SiO 2) occupying most of the by-products remaining in the exhaust system equipment is decomposed with a gas containing fluorine radicals. For example, the following reaction is caused. In the following formula, one fluorine radical molecule is represented by FR.
SiO ₂ + 4FR → SiF ₄ + O ₂
When the case where hydrogen fluoride (HF) gas is used and the case where fluorine radicals are generated from nitrogen trifluoride (NF 3) gas are compared, there are the following differences.
Regarding the amount of gas used, F is one atom in one molecule of HF, and three atoms are in one molecule of NF3. Therefore, when nitrogen trifluoride is used, an equal amount of by-product is used. The amount of gas required to remove the is small. In other words, more by-products can be removed with the same amount of gas when nitrogen trifluoride is used.
Regarding the etching efficiency (that is, the removal efficiency of by-products with the same volume of gas), when hydrogen fluoride (HF) was used, 5 times the theoretical reaction amount was required, but nitrogen trifluoride. In the case of using, since the radical molecule is used, the required amount of gas is smaller and better.

A process suitable for gas cleaning using hydrogen fluoride (HF) (that is, removal of by-products) is as follows.
The means for supplying hydrogen fluoride gas is a gas cylinder or the like, which is simpler than the means for supplying fluorine radicals, but has a low etching efficiency. Therefore, gas cleaning using hydrogen fluoride (HF)
1) A batch process in which hydrogen fluoride gas can be supplied for a long time (there is time to supply),
2) Suitable for processes where the amount of by-products in the pump is small.

On the other hand, a process suitable for gas cleaning using fluorine radicals is as follows.
Gas cleaning using fluorine radicals has high etching efficiency but requires a plasma generator.
It is suitable for 1) a single-wafer process in which the cleaning gas can be supplied for a short time (there is no sufficient time for supply), and 2) a process in which the amount of by-products in the pump is large.

  In a fifteenth aspect, the exhaust radical equipment system according to the fourteenth aspect is adopted, wherein the fluorine radical is generated from nitrogen trifluoride or carbon tetrafluoride in the plasma generator. Yes.

According to a sixteenth aspect, the gas supply device includes an exhaust system equipment system according to the fifteenth aspect, characterized by having a cylinder filled with at least one of nitrogen trifluoride and carbon tetrafluoride. The composition is taken.

In a seventeenth aspect, there is provided a cleaning method for exhaust system equipment that can be installed downstream of the chamber in order to exhaust the inside of the chamber of the manufacturing apparatus,
Providing a gas supply device capable of supplying a gas containing at least one of hydrogen halide, fluorine, chlorine, chlorine trifluoride, and fluorine radicals;
Connecting the gas supply device to the exhaust system facility;
And a step of supplying the gas to the exhaust system equipment from the gas supply device.

  According to an eighteenth aspect, the exhaust system facility has a configuration of a cleaning method according to a seventeenth aspect, which includes a vacuum pump and / or an abatement apparatus.

It is a block diagram which shows the exhaust system equipment system which concerns on one Embodiment of this invention. It is sectional drawing of the vacuum pump shown in FIG. FIG. 3 is a block diagram showing the configuration of the gas supply device. FIG. 4 is a block diagram showing a configuration of a gas supply device having a gas temperature control device for controlling the gas temperature. FIG. 5 is a block diagram showing the configuration of an exhaust system facility system having a water supply device that supplies water, which is gas or mist, to the gas. FIG. 6 shows the weight ratio of each component to the total weight of the solid by-product in the vacuum pump and the solid by-product in the vacuum pump. FIG. 7 shows the weight ratio of each component to the total weight of the solid by-product in the vacuum pump and the solid by-product in the vacuum pump. FIG. 8 is a block diagram of an embodiment having a plurality of vacuum pumps as a plurality of exhaust system facilities. FIG. 9 shows a state signal when the semiconductor manufacturing apparatus repeats the process step, the cleaning step, and the idle step. The table in FIG. 10 shows the relationship between the process step, the cleaning step, the idle step, and the opening / closing of the valve. FIG. 11 shows the drive current value of the vacuum pump when the semiconductor manufacturing apparatus is in the process step, the cleaning step, and the idle step. FIG. 12 shows the relationship between the magnitude of the driving current value of the vacuum pump, each step, and whether or not HF gas is supplied. It is a block diagram which shows the exhaust system equipment system which concerns on one Embodiment of this invention. FIG. 14 is a block diagram showing the configuration of the gas supply device. FIG. 15 shows the configuration of the plasma generator.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted. FIG. 1 is a block diagram showing an exhaust system equipment system according to an embodiment of the present invention. In the present embodiment, the exhaust system facility system includes a vacuum pump, a gas supply device, a detoxifying device, piping that connects these to each other, piping that connects the chamber and the vacuum pump, and the like. The exhaust system equipment includes a vacuum pump, a detoxifying device, piping connecting these to each other, piping connecting the chamber and the vacuum pump, and the like. In the present embodiment, the manufacturing apparatus is a semiconductor manufacturing apparatus for manufacturing a semiconductor.

  FIG. 1 shows an example in which the vacuum pump 10 is connected to the vacuum chamber 14 of the semiconductor manufacturing apparatus 12. The exhaust system facility system 16 is configured to evacuate the vacuum chamber 14 of the semiconductor manufacturing apparatus 12. A vacuum pump 10 that can be installed downstream of the vacuum chamber 14 and a gas containing hydrogen halide connected to the vacuum pump 10. And a gas supply device 18 capable of supplying the gas to the vacuum pump 10.

  Although not shown in FIG. 1, a process gas supply source for supplying a process gas to the vacuum chamber 14 is disposed upstream of the vacuum chamber 14. The vacuum chamber 14 is connected to the vacuum pump 10 by a pipe 22.

  As shown in FIG. 2, as an example of the vacuum pump 10, a first vacuum pump 30 as a booster pump, a second vacuum pump 32 as a main pump, a first vacuum pump 30, and a second vacuum pump. And a housing 34 for housing 32. Details of the vacuum pump 10 will be described later.

  In FIG. 1, an exhaust gas abatement device 24 (abatement device) for detoxifying the exhaust gas 20 (process gas) is disposed on the downstream side of the vacuum pump 10. The exhaust gas abatement device 24 includes types such as a dry adsorption method, a wet absorption (or dissolution) method, a combustion decomposition method, and a catalyst method. The catalytic method can be applied to any of the dry adsorption method, the wet absorption (or dissolution) method, and the combustion decomposition method in order to increase the detoxification efficiency. Other examples include heating (heater type) decomposition and plasma decomposition. As the exhaust gas abatement apparatus, any one of these methods can be selected, but they may be used in combination. For example, it is possible to increase the detoxification efficiency by combining the catalytic method with any one of a dry adsorption method, a wet absorption (or dissolution) method, and a combustion decomposition method. What kind of system is adopted for the abatement apparatus can be appropriately selected in consideration of, for example, the type and amount of the gas to be treated and the utility that can be used. A first control unit 26 is connected to the vacuum chamber 14, and the first control unit 26 controls process conditions for substrate processing (hereinafter referred to as the present process) in the vacuum chamber 14. Examples of the process conditions include the ventilation time, type, and temperature of the process gas supplied to the vacuum chamber 14. In the present embodiment, the operation control items of the first control unit 26 include the timing of gas flow, the gas flow rate, the temperature, and the like when the gas type is determined. In the present embodiment, in particular, since the gas flow rate, temperature, and the like are fixed, the information necessary for control is the timing of gas flow.

  The second control unit 28 is connected to the vacuum pump 10 and the valve 82, and the operation condition of the vacuum pump 10 and the opening / closing of the valve 82 are controlled by the second control unit 28. The operating conditions of the vacuum pump 10 include, for example, the rotational speed of the pump rotor, the start timing of the first vacuum pump 30 and the second vacuum pump 32, and the like.

  Note that the semiconductor manufacturing apparatus, vacuum pump, and abatement apparatus can be operated independently. Cooperation between devices is not essential. If the pump and the abatement apparatus are started once, the semiconductor manufacturing apparatus can be operated independently. However, in a standard semiconductor factory, there are cases where cooperative operation is performed using operation signals from the viewpoint of energy saving, performance improvement, and equipment protection. In that case, the starting point of the signal (control) is the semiconductor manufacturing apparatus. The vacuum pump and the abatement device change the operating state according to the command of the semiconductor manufacturing apparatus. In addition, the semiconductor manufacturing apparatus changes operation by a signal (abnormality, failure signal, etc.) from the vacuum pump and the abatement apparatus. In that sense, the communication signal is generally a bidirectional signal.

  In the present embodiment, the second control unit 28 is independent from the vacuum pump 10, but the second control unit 28 is attached to the control device or the gas supply device 18 included in the vacuum pump 10. It is good also as a control part. The second control unit 28 need not be a separate device.

  The second control unit 28 is connected to the first control unit 26, and process conditions are sent from the first control unit 26 to the second control unit 28 as state signals. The second control unit 28 controls the vacuum pump 10 and the valve 82 based on the state signal. In the present embodiment, the second control unit 28 is not a control device above the vacuum pump 10 but a control unit below the vacuum pump 10. That is, the gas supply device 18 is positioned as an auxiliary facility of the vacuum pump 10, and the second control unit 28, which is a control unit of the gas supply device 18, is a lower-level control unit of the vacuum pump 10.

  In FIG. 2, the first vacuum pump 30 is an example of a roots-type vacuum pump having a pair of root-type pump rotors 36 (only one pump rotor is shown in FIG. 2). This is a Roots-type vacuum pump having a pair of Roots-type pump rotors 38 (only one pump rotor is shown in FIG. 2). The first vacuum pump 30 and the second vacuum pump 32 have pump rotors with different numbers of stages, respectively. The first vacuum pump 30 and the second vacuum pump 32 are installed in parallel with each other in the housing 34, and the first vacuum pump 30 is disposed above the second vacuum pump 32.

  An intake pipe 40 is provided at the intake port of the first vacuum pump 30, and the intake pipe 40 is connected to the vacuum chamber 14 via the pipe 22. Examples of the semiconductor manufacturing apparatus 12 include a film forming apparatus and an etching apparatus that perform a film forming process or an etching process on a substrate such as a semiconductor wafer or a liquid crystal panel. An exhaust port is provided in the lower portion of the first vacuum pump 30, and this exhaust port is connected to the intake port of the second vacuum pump 32 via a connection pipe 42. An exhaust pipe 44 is connected to the exhaust port of the second vacuum pump 32, and a gas (process gas or the like) is exhausted to the outside through the exhaust pipe 44. In addition to the process gas, the gas includes a cleaning gas and an inert gas for dilution. Thus, the first vacuum pump 30 and the second vacuum pump 32 are connected in series, and the second vacuum pump 32 is disposed on the downstream side of the first vacuum pump 30. That is, the first vacuum pump 30 is disposed on the vacuum side with respect to the second vacuum pump 32, and the second vacuum pump 32 is disposed on the atmosphere side.

  As shown in FIG. 2, the first vacuum pump 30 includes a pair of multistage pump rotors 36 that face each other. Each pump rotor 36 includes a first-stage root rotor 36a (intake-side rotor) disposed on the intake side, a second-stage root rotor 36b (exhaust-side rotor) disposed on the exhaust side, and the root rotors 36a, 36a, And a rotating shaft 46 to which 36b is fixed. A motor M <b> 1 that drives the first vacuum pump 30 is fixed to the end of the rotating shaft 46. (Comment: The description of timing gears 48 and 52 will be deleted from the description and Fig. 2.)

  The second vacuum pump 32 is different from the first vacuum pump 30 in that it includes a five-stage pump rotor. Other configurations of the second vacuum pump are the same as those of the first vacuum pump, and redundant description thereof is omitted. As shown in FIG. 2, the second vacuum pump 32 includes a pair of multistage pump rotors 38 that face each other. Each pump rotor 38 includes a first-stage root rotor 38a, a second-stage root rotor 38b, a third-stage root rotor 38c, and a fourth-stage root rotor 38d that are arranged in order from the intake side to the exhaust side. A fifth stage root rotor 36e and a rotating shaft 50 to which these root rotors are fixed are provided. The motor M <b> 2 that drives the second vacuum pump 32 is fixed to the end of the rotating shaft 50.

Small gaps are formed between the pump rotors 36 and 38 and between the pump rotors 36 and 38 and the inner surface of the rotor casing 34, so that the pump rotors 36 and 38 are not contacted in the rotor casing 34. It can be rotated. If a by-product such as SiO ₂ is caught in the minute gap, the rotation of the pump rotors 36 and 38 becomes defective or stops. In this embodiment, a roots type is used as the rotor, but the present invention is not limited to this, and a screw type, a claw type, or the like may be used. In either case, a multistage pump rotor in which a plurality of rotors are arranged in the axial direction is used. Further, the number of stages of the pump rotors 36 and 38 is not limited to two or five, but may be three or more, or five or more or five or less, respectively.

  The exhaust system facility system 16 includes an intake pipe 40 that is a connection portion with the semiconductor manufacturing apparatus 12. The gas supply device 18 is connected to the exhaust system facility system 16 in the intake pipe 40. The reason for connecting to the intake pipe 40 is that since the intake pipe 40 is located upstream of the vacuum pump 10, if the HF gas is supplied from the intake pipe 40, the entire vacuum pump 10 can be cleaned.

  As a place for supplying the HF gas, the HF gas may be supplied from a connection pipe 42 connecting the first vacuum pump 30 and the second vacuum pump 32. Moreover, you may supply HF gas from the arbitrary places of the 2nd vacuum pump 32 which is a main pump. The reason for supplying the HF gas only to the second vacuum pump 32 is that the second vacuum pump 32 has a higher internal pressure and higher temperature than the first vacuum pump 30 and may easily generate a product. Because. Depending on the manufacturing process or the like of the semiconductor manufacturing apparatus 12, the place where the by-product is likely to be caught or the place where the by-product is easily generated varies.

  Next, the gas supply device 18 will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the gas supply device 18. FIG. 3A shows a case where HF gas and N 2 gas are supplied to the gas supply device 18 from the outside of the exhaust system system 16. HF gas is supplied via a pipe 56 and N 2 gas is supplied via a pipe 58. FIG. 3B shows a case where the gas supply device 18 has a cylinder 54 filled with hydrogen halide, and N 2 gas is supplied from the outside of the exhaust system system 16.

  N2 gas is used to adjust the concentration of HF gas. The HF gas supply device 18 supplies the HF gas and the N 2 gas supplied to the gas supply device 18 to the vacuum pump 10 at an optimal HF concentration, a flow rate, and an optimal supply timing. HF gas and N 2 gas are mixed and then sent to the vacuum pump 10. MFC in the figure is a mass flow controller. Before and after the MFC, a valve 90 for opening and closing the pipe is provided. Instead of the MFC, a similar function may be realized by using an ONOFF valve such as a mass flow meter and a remotely operated solenoid valve and a flow rate adjusting valve. When the cylinder 54 is used, it becomes unnecessary to supply HF gas from the outside of the exhaust system system 16, and a long pipe for supplying HF gas from the outside becomes unnecessary. For this reason, the installation work becomes easy and the cost is reduced.

  Next, another embodiment of the gas supply device 18 will be described with reference to FIG. FIG. 4 is a block diagram showing a configuration of the gas supply device 18 having a heater 60 (gas temperature control device) for controlling the gas temperature. FIG. 4A shows a case where HF gas and N 2 gas are supplied to the gas supply device 18 from the outside of the exhaust system system 16. FIG. 4B shows a case where the gas supply device 18 has a cylinder 54 filled with hydrogen halide, and N 2 gas is supplied from the outside of the exhaust system system 16.

  The heater 60 automatically controls the heating of the HF gas to the optimum temperature for cleaning. The optimum temperature for cleaning is 50 ° C. to 250 ° C. in the case of the above-described reaction for producing silicon fluoride from silicon dioxide. Below this temperature range, the reaction is weak, and above this temperature range, the operation of the apparatus is affected. If the reaction is weak, silicon dioxide cannot be removed sufficiently. The influence on the device means that each part of the device may be damaged by deformation or corrosion due to local heating.

The heater 60 is wound around the outer periphery of the pipe 62. The HF gas temperature is measured by the temperature sensor, and the second control unit 28 controls the output of the heater 60 based on the measured temperature. The gas temperature control device may be arranged in the vacuum pump 10 in addition to the gas supply device 18.

  Next, another embodiment of the exhaust system facility system 16 will be described with reference to FIG. FIG. 5 is a block diagram showing a configuration of an exhaust system facility system 16 having a water supply device for supplying water, which is gas or mist, to the gas. In the exhaust system facility system 16, a mixture of water and gas is supplied to the vacuum pump 10. Water is entrained in the HF gas supplied to the vacuum pump 10, and a by-product inside the vacuum pump 10 is reacted with the HF gas using water. A moderate amount of moisture improves the efficiency of the reaction for producing silicon fluoride from silicon dioxide as described above.

  In FIG. 5A, a spray nozzle 64 that discharges water as mist is disposed in a pipe 62 that connects the gas supply device 18 and the vacuum pump 10. The water supply device includes a spray nozzle 64, a flow rate controller 74 (FIC) that adjusts the amount of water discharged from the spray nozzle 64, and a valve 76. Water is supplied to the flow controller 74 from the outside of the exhaust system system 16. The spray nozzle 64 discharges water in a direction 68 opposite to the direction 66 in which the HF gas flows. The reason for releasing water in the opposite direction 68 is to mix HF gas and water well.

  In FIG. 5B, the water supply device has a water tank 72 provided with a heating device 70. Water is supplied to the water tank 72 from outside the exhaust system system 16. A pipe 88 extending from the upper part of the water tank 72 provided with the heating device 70 is connected to the pipe 62 connecting the gas supply device 18 and the vacuum pump 10. Since the inside of the pipe 62 is evacuated by the vacuum pump 10, the inside of the water tank 72 is kept in a vacuum. For this reason, in the water tank 72, water vapor | steam generate | occur | produces and the inside of the water tank 72 becomes low temperature by evaporation heat. A heating device 70 is provided to prevent the water from cooling down until the water changes to ice. The steam is supplied to the by-product inside the vacuum pump 10 together with the HF gas.

  Next, in this embodiment, how much by-product remaining in the vacuum pump 10 is removed by hydrogen halide when a gas containing hydrogen halide is supplied to the vacuum pump 10. FIG. 6 shows the result of confirming the above by the test. In this test, the remaining solid by-product was collected in the container from the inside of the vacuum pump 10 actually used. A gas containing hydrogen halide was supplied to the by-product in the container. The weight of the solid by-product in the container was measured before supplying the gas and after the test was completed. In the test, a gas containing hydrogen halide was supplied for a set time.

FIG. 6 shows the weight ratio of each component to the total weight of the solid by-product in the container and the solid by-product in the container before supplying the gas. Before supplying gas, silicon dioxide accounted for 95%. When the weight of the silicon dioxide was measured after the reaction with the gas was completed, the weight of the silicon dioxide was greatly reduced below the detectable weight. The solid by-product in the container almost disappeared visually. Most of the solid silicon dioxide is thought to have changed to gaseous silicon fluoride (SiF ₄ ) and ammonium silicofluoride ((NH ₄ ) ₂ SiF ₆ ).

  FIG. 7 shows the test results for a process different from FIG. This test is a test using a solid by-product remaining in the vacuum pump 10 used in a semiconductor manufacturing process different from FIG. Solid by-products remaining in the vacuum pump 10 used in the semiconductor manufacturing process different from that shown in FIG. 6 were collected in a container. A gas containing hydrogen halide was supplied into the container, and the weight of the solid by-product in the container was measured before supplying the gas and after the reaction with the gas was completed.

  In FIG. 7, the weight ratio of each component with respect to the total weight of the component contained in the solid by-product in a glass container before filling with gas and the solid by-product in a container is shown. Before supplying gas, silicon dioxide accounted for 71%. When the weight of the silicon dioxide was measured after the reaction with the gas was completed, the weight of the silicon dioxide was greatly reduced below the detectable weight. Si, F, O content accounted for 17%. After the reaction with the gas was completed, the weight of the Si, F, O-containing material was measured. As a result, the weight of the Si, F, O-containing material was significantly reduced to a detectable weight or less. The solid by-product in the container almost disappeared visually. Most of the solid silicon dioxide and Si, F, O-containing materials are considered to have changed to gaseous silicon fluoride (SiF4) or the like.

  Next, an embodiment of an exhaust system facility system that supplies gas to a plurality of exhaust system facilities from one gas supply device will be described with reference to FIG. FIG. 8 is a block diagram of an embodiment having a plurality of vacuum pumps 10 as a plurality of exhaust system facilities. HF gas is supplied from one HF gas supply device 18 to a plurality of vacuum pumps 10. The vacuum pump 10 has a connection part with the piping 62 in order to receive HF gas. The connection part is a screw-type connector or the like.

  Next, a control method for supplying gas from the gas supply device to the exhaust system facility will be described with reference to FIG. The exhaust system facility system 16 includes a second control unit 28 that controls the supply of gas from the gas supply device 18 to the vacuum pump 10. The second control unit 28 performs control based on a state signal 78 indicating the operation state of the semiconductor manufacturing apparatus 12 output from the semiconductor manufacturing apparatus 12.

  The state signal 78 indicating the operation state of the semiconductor manufacturing apparatus 12 will be described below. For example, in the process performed by the semiconductor manufacturing apparatus 12 that forms a film on a wafer, the “process process” for forming the film and the environment in the semiconductor manufacturing apparatus 12 contaminated by the “process process” are brought into a clean state. There is a “cleaning process” performed for returning, and an “idle process” which is a standby state other than those. The removal of by-products in the vacuum pump 10 by HF gas is not affected by the operating state of the semiconductor manufacturing apparatus 12. Removal of by-products inside the vacuum pump 10 is possible in any of the above steps. However, during the process steps, it is necessary to eliminate the possibility that removal of by-products inside the vacuum pump 10 will affect the operating state of the semiconductor manufacturing apparatus 12 (deposition quality). For this reason, it is necessary to prevent mixing of HF gas from the vacuum pump 10 to the semiconductor manufacturing apparatus 12. During the process steps, it is not desirable to perform cleaning of the vacuum pump 10 with HF gas. Therefore, in order to avoid supply of HF gas to the vacuum pump 10 when the semiconductor manufacturing apparatus 12 is a process step, it is desirable to perform cleaning of the vacuum pump 10 with HF gas other than the process step. In order to determine whether the process is a process step, a state signal 78 indicating the operation state of the semiconductor manufacturing apparatus 12 is used.

  By the way, the status signal 78 can be used as follows. The gas types and gas flow rates used in the semiconductor manufacturing apparatus 12 differ depending on the “process step”, “cleaning step”, and “idle step”. In the case of the exhaust gas abatement device 24, particularly a combustion type abatement device, depending on the gas type and gas flow rate, it is necessary to perform combustion under optimum combustion conditions. That is, it is necessary to optimize the removal efficiency of the processing target gas in the exhaust gas abatement apparatus 24. Therefore, the exhaust gas abatement apparatus 24 receives a state signal 78 indicating which process is being performed by the semiconductor manufacturing apparatus 12 from the first control unit 26 of the semiconductor manufacturing apparatus 12, and the operating state of the semiconductor manufacturing apparatus 12. The combustion conditions corresponding to it are realized.

An example of the status signal 78 is shown in FIG. FIG. 9A shows a state signal 78 when the semiconductor manufacturing apparatus 12 repeats the process step, the cleaning step, and the idle step in this order. The status signal 78 can be, for example, a digital signal “0”, “1”, or “2” to identify a process step, a cleaning step, or an idle step. Further, the status signal 78 can be an analog signal, and the signal level of the analog signal can be a three-stage signal. In FIG. 9B, after repeating the process step and the idle step a plurality of times (FIG. 9B shows the case of four times), the semiconductor manufacturing apparatus 12 performs the cleaning step. FIG. 9B shows a state signal 78 when the semiconductor manufacturing apparatus 12 repeats this order. FIG. 9C shows a state signal 78 when the semiconductor manufacturing apparatus 12 repeats only the process step and the idle step in this order.

  Whether the HF gas is supplied to the vacuum pump 10 when the semiconductor manufacturing apparatus 12 performs each of the process step, the cleaning step, and the idle step will be described with reference to a table shown in FIG. The table of FIG. 10 shows the relationship between each process, the presence or absence of HF gas supply, and the opening and closing of the valve 82. As shown in the table of FIG. 10, HF gas is not supplied in the process step. HF gas is supplied in the cleaning process and the idle process. In each step, the second control unit 28 outputs a signal 86 for controlling the opening and closing of the valve 82 that is a valve for supplying HF gas to the valve 82. Based on the signal 86, the second controller 28 closes the valve 82 in the process step and opens it in the cleaning step and the idle step.

  The second control unit 28 receives the status signal 78 from the first control unit 26, but the second control unit 28 can also receive the status signal 78 via another path. That is, since the exhaust gas abatement device 24 has received the status signal 78 from the first control unit 26, the second control unit 28 receives the status signal 84 that is the same as the status signal 78 from the exhaust gas abatement device 24. Can be received. The second control unit 28 controls the valve 82 as shown in FIG. 10 based on the state signal 84 output from the exhaust gas abatement apparatus 24.

  Next, another embodiment of the control method by the second control unit 28 will be described with reference to FIG. In this embodiment, the control for supplying or stopping the HF gas from the gas supply device 18 to the vacuum pump 10 is performed by determining the operation state of the semiconductor manufacturing device 12 from the state signal of the vacuum pump 10. The second control unit 28 performs supply control of HF gas based on a state signal 88 indicating an operation state of the exhaust system equipment, for example, the vacuum pump 10 output from the vacuum pump 10. FIG. 11 shows the drive current value of the vacuum pump 10 when the semiconductor manufacturing apparatus 12 is in the process step, the cleaning step, and the idle step. In the figure, the horizontal axis represents time, and the vertical axis represents drive current value (A: ampere). In the present embodiment, the drive current value is the state signal 88 of the vacuum pump 10.

  The magnitude of the drive current value of the vacuum pump 10 is A3 in the process step, A2 in the cleaning step, and A1 in the idle step. In the present embodiment, the magnitude decreases in the order of the process step, the cleaning step, and the idle step. The relationship between the semiconductor manufacturing process and the pump current is conceptually shown in FIG. Actually, it is not always a simple pulse waveform as shown in FIG. However, the process step, the cleaning step, and the idle step can be distinguished by the magnitude of the drive current value of the vacuum pump 10.

  Whether the HF gas is supplied to the vacuum pump 10 when the semiconductor manufacturing apparatus 12 performs each of the process step, the cleaning step, and the idle step will be described with reference to a table shown in FIG. The table of FIG. 12 shows the relationship between the magnitude of the drive current value of the vacuum pump 10, each step, the presence / absence of HF gas supply, and the opening / closing of the valve 82. As shown in the table of FIG. 12, HF gas is not supplied in the process step. HF gas is supplied in the cleaning process and the idle process. In each step, the second control unit 28 outputs a signal 86 for controlling the opening / closing of the valve 82 to the valve 82. Based on the signal 86, the second controller 28 closes the valve 82 in the process step and opens it in the cleaning step and the idle step.

In the exhaust system facility system 16 shown in FIG. 1, a method for cleaning the vacuum pump 10 that can be installed downstream of the chamber 14 to exhaust the inside of the chamber 14 of the semiconductor manufacturing apparatus 12 is as follows. A gas supply device 18 capable of supplying a gas containing hydrogen halide is provided in the exhaust system system 16. The gas supply device 18 is connected to the vacuum pump 10. Gas is supplied to the vacuum pump 10 from the gas supply device 18.

  Next, an embodiment in which the gas supply apparatus has a plasma generator and fluorine radicals are generated by the plasma generator will be described with reference to FIGS. Fluorine radicals are generated in a plasma generator, for example from nitrogen trifluoride or carbon tetrafluoride. In FIG. 13, the exhaust system facility system 16 includes a gas supply device 118 that can supply a gas containing fluorine radicals to the vacuum pump 10.

  Next, the gas supply device 118 will be described with reference to FIG. FIG. 14 is a block diagram showing a configuration of the gas supply device 18. The case where NF3 gas and N2 gas (and / or Ar gas) are supplied to the gas supply device 118 from the outside of the exhaust system system 16 is shown. The NF 3 gas is supplied via the pipe 156 and the N 2 gas is supplied via the pipe 58. N2 gas is used to adjust the concentration of NF3 gas.

  The NF3 gas and N2 gas supplied to the gas supply device 18 are supplied to the plasma generator 92 at an optimal NF3 concentration, flow rate, and optimal supply timing. The NF 3 gas and the N 2 gas are mixed and then sent to the plasma generator 92. The plasma generator 92 generates a fluorine radical gas 94 and supplies the fluorine radical gas 94 to the vacuum pump 10.

  Next, the plasma generator 92 will be described with reference to FIG. There are various methods for generating plasma. A method of generating an arbitrary plasma can be applied to this embodiment. Examples of a method for generating plasma include a barrier discharge method, a creeping discharge method, and a high frequency discharge method. FIG. 15 shows a kind of barrier discharge method. The plasma generator 92 includes a high voltage electrode 96 provided with a V-shaped trench groove 102, a dielectric plate 98, and a ground electrode 100. A small gap (gap) is provided between the trench groove 102 of the high-voltage electrode 96 and the dielectric plate 98 to form a discharge space 104. The trench groove 102 is filled with a dielectric. The discharge space 104 is supplied with NF3 gas and N2 gas.

  A high frequency high voltage is applied between the high voltage electrode 96 and the ground electrode 100 by the high voltage AC power source 106. When a high frequency high voltage is applied, corona discharge (silent discharge) occurs in the discharge space 104. In the NF3 gas guided to the discharge space 104, fluorine becomes a fluorine radical due to discharge energy. The barrier discharge method is advantageous in that the discharge start voltage is low, the amount of fluorine radicals generated is large, and the concentration of fluorine radicals is high.

  As mentioned above, although the example of embodiment of this invention was demonstrated, above-described embodiment of this invention is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention naturally includes equivalents thereof. In addition, any combination or omission of each constituent element described in the claims and the specification is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect is achieved. It is.

DESCRIPTION OF SYMBOLS 10 ... Vacuum pump 12 ... Semiconductor manufacturing apparatus 14 ... Vacuum chamber 16 ... Exhaust system equipment 18 ... Gas supply apparatus 20 ... Exhaust gas 22 ... Piping 24 ... Exhaust gas abatement apparatus 26 ... 1st control part 28 ... 2nd control part

Claims (18)

In order to exhaust the inside of the chamber of the manufacturing apparatus, exhaust system equipment that can be installed downstream of the chamber;
A gas supply device connected to the exhaust system facility and capable of supplying a gas containing at least one of hydrogen halide, fluorine, chlorine, chlorine trifluoride, and fluorine radicals to the exhaust system facility. A featured exhaust system system. The exhaust system facility has a connection portion with the manufacturing apparatus,
The exhaust system equipment system according to claim 1, wherein the gas supply device is connected to the exhaust system equipment at the connection portion.   The exhaust system system according to claim 1 or 2, wherein the gas supply device includes a cylinder filled with at least one of hydrogen halide, fluorine, chlorine, and chlorine trifluoride.   The exhaust system equipment system according to any one of claims 1 to 3, further comprising a gas temperature control device that controls a temperature of the gas.   5. The exhaust system system according to claim 4, wherein the gas temperature control device controls the temperature of the gas in a range of 50 ° C. to 250 ° C. 6.   The exhaust system according to any one of claims 1 to 5, wherein there are a plurality of exhaust system facilities, and the gas is supplied from one gas supply device to the plurality of exhaust system facilities. System system.   The exhaust system facility system includes a water supply device that supplies water, which is gas or mist, to the gas, and a mixture of the water and the gas is supplied to the exhaust system facility. Item 7. The exhaust system system according to any one of Items 1 to 6.   The exhaust system facility system includes a control unit that controls supply of the gas from the gas supply device to the exhaust system facility, and the control unit indicates an operation state of the manufacturing apparatus that is output by the manufacturing apparatus. The exhaust system system according to any one of claims 1 to 7, wherein the control is performed based on a state signal. The exhaust system facility system has a control unit that controls supply of the gas from the gas supply device to the exhaust system facility,
For the abatement device installed downstream of the exhaust system facility and detoxifying the exhaust gas discharged from the exhaust system facility, the manufacturing apparatus outputs a status signal indicating the operating state of the manufacturing apparatus And
The exhaust according to any one of claims 1 to 7, wherein the control unit receives the status signal from the abatement apparatus and performs the control based on the received status signal. System system.   The exhaust system facility system includes a control unit that controls the supply of the gas from the gas supply device to the exhaust system facility, and the control unit operates the exhaust system facility output by the exhaust system facility. The exhaust system equipment system according to any one of claims 1 to 7, wherein the control is performed based on a state signal indicating the following. The exhaust system facility according to any one of claims 1 to 8, and 10, wherein the exhaust system facility includes a detoxifying device that processes the exhaust gas discharged from the chamber to render it harmless. system.   The exhaust system equipment according to any one of claims 1 to 11, wherein the exhaust system equipment includes a vacuum pump.   The exhaust system system according to any one of claims 1 to 12, wherein the manufacturing apparatus is a semiconductor manufacturing apparatus for manufacturing a semiconductor.   The exhaust system system according to any one of claims 1 to 13, wherein the gas supply device includes a plasma generator, and the fluorine radicals are generated by the plasma generator.   15. The exhaust system system according to claim 14, wherein the fluorine radical is generated from nitrogen trifluoride or carbon tetrafluoride in the plasma generator.   16. The exhaust system system according to claim 15, wherein the gas supply device has a cylinder filled with at least one of nitrogen trifluoride and carbon tetrafluoride. An exhaust system cleaning method that can be installed downstream of the chamber to exhaust the interior of the chamber of the manufacturing apparatus,
Providing a gas supply device capable of supplying a gas containing at least one of hydrogen halide, fluorine, chlorine, chlorine trifluoride, and fluorine radicals;
Connecting the gas supply device to the exhaust system facility;
And a step of supplying the gas from the gas supply device to the exhaust system facility.   The cleaning method according to claim 17, wherein the exhaust system facility includes a vacuum pump and / or a detoxification device that treats exhaust gas discharged from the chamber and renders it harmless.

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