JP2007243014A - Method of manufacturing semiconductor device and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise through-put by rapidly removing halogen species when a cleaning process with halogen gas is included as the process of substrate processing 1. <P>SOLUTION: A method of manufacturing a semiconductor includes: a step of carrying a substrate 8 into a processing chamber 7; a step of supplying processing gas to the processing chamber and processing the substrate; a step of carrying the processed substrate out of the processing chamber; a step of supplying the halogen gas to the processing chamber and cleaning the processing chamber; and a step of supplying vapor, which is obtained by combusting oxygen gas and hydrogen gas, to the processing chamber and removing the remaining halogen species in the processing chamber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing method and a substrate processing apparatus for manufacturing a semiconductor device by performing processes such as thin film generation, impurity diffusion, annealing, and etching on a substrate such as a wafer and a glass substrate.

  There is a substrate processing step as one step for manufacturing a semiconductor device. As a substrate processing, a substrate such as a wafer or a glass substrate is subjected to processing such as generation of a thin film, diffusion of impurities, annealing processing, etching and the like by a CVD method. In addition, a cleaning process is performed for removing by-products deposited on the inner wall surface of the processing chamber or the like at every processing or periodically.

  As one of the cleaning operations, there is a dry etching method (Self-Cleaning) using a halogen-based gas containing fluorine and chlorine. When the processing chamber is cleaned by a dry etching method using a halogen-based gas, halogen species remain in the processing chamber. The halogen species is a film formation inhibiting factor in the film formation process, and the residual halogen species affects the film formation quality. For this reason, conventionally, after the processing chamber is cleaned by dry etching, the halogen species are removed.

  As a conventional halogen species removal method or a method for removing the influence of halogen species, the treatment chamber is cleaned by dry etching and then the treatment chamber is purged with N2 and NH3 for a long time, and the CVD method is used. A method of generating a SiN coating film (for example, a thickness of 4000 mm) has been performed.

  However, in the method of purging with N2 and NH3, the gas purging time takes 1 to 4 hours. Further, for example, when a 4000 N SiN film is formed as a coating film, a long-time treatment such as 5 hours is required, which hinders improvement in throughput.

JP 2003-51452 A

  In view of such circumstances, the present invention enables rapid removal of halogen species and improves throughput when a cleaning process using a halogen-based gas is included as one process of substrate processing.

  The present invention includes a step of loading a substrate into a processing chamber, a step of supplying a processing gas to the processing chamber to process the substrate, a step of unloading the processed substrate from the processing chamber, and a halogen in the processing chamber. Supplying a system gas to clean the processing chamber; and supplying a water vapor generated by burning oxygen gas and hydrogen gas to the processing chamber to remove residual halogen species in the processing chamber. The present invention relates to a method for manufacturing a semiconductor device.

  The present invention also provides a processing chamber for processing a substrate, a processing gas introduction tube for introducing a processing gas into the processing chamber, a halogen-based gas introduction tube for introducing a halogen-based gas as a cleaning gas into the processing chamber, and the processing A water vapor introducing pipe for introducing water vapor into the chamber, a water vapor generating apparatus connected to the water vapor introducing pipe for generating water vapor by burning oxygen gas and hydrogen gas, an exhaust pipe for exhausting the processing chamber, and the processing A control device for controlling so as to remove the residual halogen species in the processing chamber by introducing water vapor from the water vapor generating device into the processing chamber after introducing a halogen-based gas into the chamber and cleaning the processing chamber; The present invention relates to a substrate processing apparatus having

  According to the present invention, a step of loading a substrate into a processing chamber, a step of processing a substrate by supplying a processing gas to the processing chamber, a step of unloading the processed substrate from the processing chamber, and the processing chamber Supplying a halogen-based gas to the process chamber and cleaning the process chamber; and supplying the process chamber with water vapor generated by burning oxygen gas and hydrogen gas to remove residual halogen species in the process chamber; Therefore, rapid removal of halogen species is possible, and throughput can be improved.

  The present invention also provides a processing chamber for processing a substrate, a processing gas introduction tube for introducing a processing gas into the processing chamber, a halogen-based gas introduction tube for introducing a halogen-based gas as a cleaning gas into the processing chamber, and the processing A water vapor introducing pipe for introducing water vapor into the chamber, a water vapor generating apparatus connected to the water vapor introducing pipe for generating water vapor by burning oxygen gas and hydrogen gas, an exhaust pipe for exhausting the processing chamber, and the processing A control device for controlling so as to remove the residual halogen species in the processing chamber by introducing water vapor from the water vapor generating device into the processing chamber after introducing a halogen-based gas into the chamber and cleaning the processing chamber; Therefore, it is possible to quickly remove halogen species and to exhibit excellent effects such as an improvement in throughput.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The substrate processing apparatus in which the present invention is implemented includes a single-wafer type substrate processing apparatus that processes substrates one by one, a batch type substrate processing apparatus that processes a required number of substrates at once, and a batch type substrate processing apparatus. The substrate processing apparatus includes a vertical type substrate processing apparatus provided with a vertical type processing furnace and a horizontal type substrate processing apparatus provided with a horizontal type processing furnace.

  The following describes a batch type substrate processing apparatus including a vertical processing furnace as an example in which the present invention is implemented. FIG. 1 shows a vertical processing furnace (hereinafter referred to as a processing furnace) 1.

  The processing furnace 1 has a heater 2 as a heating means. The heater 2 has a cylindrical shape and is vertically installed by being supported by a heater base 3 as a holding plate.

  Inside the heater 2, a process tube 4 is disposed as a reaction tube concentrically with the heater 2. The process tube 4 includes an internal reaction tube 5 and an external reaction tube 6 provided concentrically on the outside thereof.

  The inner reaction tube 5 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC) and has a cylindrical shape with an upper end and a lower end opened, and the outer reaction tube 6 is formed of quartz or silicon carbide, for example. It has a cylindrical shape with a top end closed and a bottom end open.

  A processing chamber 7 is defined inside the internal reaction tube 5, and a wafer 8 as a processing substrate is held by a boat 9 in the processing chamber 7 and can be stored. The boat 9 is made of a heat-resistant material such as quartz or silicon carbide, and is configured to hold a predetermined number of wafers 8 in a horizontal posture and in a state where the centers are aligned with each other and held in multiple stages. In the lower part of the boat 9, a plurality of heat insulating plates 11, which are disk-shaped heat insulating members made of a heat resistant material such as quartz or silicon carbide, are arranged in multiple stages in a horizontal posture. It is configured so that the heat from the heat is not easily transmitted to the manifold 12 side.

  Below the external reaction tube 6, the manifold 12 is disposed concentrically with the external reaction tube 6. The manifold 12 is made of, for example, stainless steel and has a cylindrical shape with an upper end and a lower end opened. The external reaction tube 6 is installed in an airtight manner at the upper end of the manifold 12 and protrudes from the inner wall of the manifold 12. The internal reaction tube 5 is erected on the inner flange 13 formed. A reaction vessel is formed by the process tube 4 and the manifold 12.

  The lower end opening of the manifold 12 forms a furnace opening, and the furnace opening is hermetically closed by a seal cap 14. The seal cap 14 is made of a metal such as stainless steel and is formed in a disc shape. . The seal cap 14 is supported by the boat elevator 10 so as to be movable up and down, and the boat 9 is placed on the seal cap 14 via a boat cradle 46 (described later).

  The seal cap 14 is provided with a first nozzle 15, a second nozzle 16, a third nozzle 17, and a fourth nozzle 18 as gas introduction portions so as to communicate with the processing chamber 7. , 18 are connected to a first gas supply pipe 21, a second gas supply pipe 22, a third gas supply pipe 23, and a fourth gas supply pipe 24, respectively.

  The first gas supply pipe 21 is provided with a first gas flow rate controller 25, a first on-off valve 26, and a first processing gas supply source 27 toward the upstream side, from the first processing gas supply source 27. For example, SiH2 Cl2 is supplied as a processing gas. The second gas supply pipe 22 is provided with a second gas flow rate controller 28, a second on-off valve 29, and a second processing gas supply source 30 toward the upstream side, from the second processing gas supply source 30. For example, NH3 is supplied as a processing gas.

  The third gas supply pipe 23 is provided with a third gas flow rate controller 31, a third on-off valve 32, a cleaning gas supply source 33, or an inert gas supply source (not shown) toward the upstream side. The cleaning gas supply source 33 supplies a halogen-based gas as a cleaning gas, and the inert gas supply source supplies, for example, nitrogen gas as an inert gas.

  The first gas flow controller 25, the second gas flow controller 28, the third gas flow controller 31, the first on-off valve 26, the second on-off valve 29, and the third on-off valve 32 are gas It is electrically connected to the flow rate control unit 34 and controlled to be supplied at a predetermined timing so that the gas flow rate supplied by the gas flow rate control unit 34 becomes a predetermined value.

  The fourth gas supply pipe 24 is connected to a steam generator 36 which will be described later.

  An exhaust line 37 for exhausting the atmosphere of the processing chamber 7 is connected to the manifold 12, and the exhaust line 37 is a cylindrical space 38 formed between the internal reaction tube 5 and the external reaction tube 6. It communicates with the lower end of the. The exhaust line 37 includes a main exhaust line 37a and a slow exhaust line 37b. A vacuum exhaust device 42 such as a vacuum pump is connected to the exhaust line 37 via a pressure sensor 39 and a pressure adjusting device 41, and vacuum exhaust is performed so that the pressure in the processing chamber 7 becomes a predetermined pressure (degree of vacuum). It is configured to be able to.

  A pressure control unit 43 is electrically connected to the pressure adjustment device 41 and the pressure sensor 39, and the pressure control unit 43 is controlled by the pressure adjustment device 41 based on the pressure detected by the pressure sensor 39. Control is performed at a desired timing so that the pressure in the processing chamber 7 becomes a desired pressure.

  A rotation mechanism 44 that rotates the boat 9 is provided on the lower surface side of the seal cap 14. A rotation shaft 45 of the rotation mechanism 44 penetrates the seal cap 14 and is connected to the boat cradle 46, and the rotation mechanism 44 can rotate the boat 9 via the boat cradle 46. The wafer 9 is rotated by rotating the boat 9.

  The seal cap 14 is configured to be moved up and down in the vertical direction by the boat elevator 10, so that the boat 9 can be loaded into and removed from the processing chamber 7. A drive control unit 47 is electrically connected to the rotation mechanism 44 and the boat elevator 10 and is configured to control at a desired timing so as to perform a desired operation.

  In the cylindrical space 38, a temperature sensor 48 is erected from the lower part to the upper part of the internal reaction tube 5. A temperature control unit 49 is electrically connected to the heater 2 and the temperature sensor 48, and the temperature control unit 49 determines the energization state of the heater 2 based on temperature information detected by the temperature sensor 48. By adjusting the temperature, the temperature of the processing chamber 7 is controlled to have a desired temperature distribution.

  The gas flow rate control unit 34, the pressure control unit 43, the drive control unit 47, and the temperature control unit 49 also constitute an operation unit and an input / output unit, and are electrically connected to the main control unit 51 that controls the entire substrate processing apparatus. Connected. The gas flow rate controller 34, the pressure controller 43, the drive controller 47, the temperature controller 49, and the main controller 51 are configured as a controller 52.

  Next, the water vapor generator 36 will be described with reference to FIGS.

  First, FIG. 2 shows a first example. In the first example, an external combustion device is used to generate steam.

  The steam generator 36 includes a hydrogen (H 2) gas source 63, an oxygen (O 2) gas source 64, and an external combustion device 65. The external combustion apparatus 65 is connected to the fourth gas supply pipe 24, and the H2 gas source 63 and the O2 gas source 64 are connected to the external combustion apparatus 65 via gas supply pipes 66 and 67, respectively. The supply pipe 66 is provided with an opening / closing valve 68 and a flow rate controller 69, and the gas supply pipe 67 is provided with an opening / closing valve 71 and a flow rate controller 72.

  A gas flow rate controller 34 is electrically connected to the flow rate controllers 69, 72, the open / close valves 68, 71, and the external combustion device 65, and is supplied from the H 2 gas source 63 and the O 2 gas source 64. The flow rate of H2 gas and O2 gas to be generated and the flow rate of water vapor (H2 O) generated and supplied by the external combustion device 65 are controlled at a desired timing.

  In the steam generator 36 of the first example, H2 gas and O2 gas supplied from the H2 gas source 63 and the O2 gas source 64 are burned by the external combustion device 65 to generate water vapor (H2 O). The generated water vapor (H 2 O) is supplied from the external combustion device 65 to the processing chamber 7 through the fourth gas supply pipe 24.

  As a second example of a method for generating water vapor (H2 O) by the water vapor generator 36, there is a method utilizing a catalytic reaction. In the second example, a catalytic reaction device 73 is used instead of the external combustion device 65 in the method of the first example of FIG. Other configurations are the same as those in the first example.

  In the steam generator 36 of the second example, the H2 gas and O2 gas supplied from the H2 gas source 63 and the O2 gas source 64 come into contact with a catalyst such as platinum provided in the catalyst reaction device 73, and the platinum or the like. The H2 gas and O2 gas that have come into contact with the catalyst are activated by the catalytic action of platinum or the like, and the reactivity is increased. The activated H2 gas and O2 gas react at a temperature lower than the ignition temperature to generate water vapor (H2 O). The generated water vapor (H 2 O) is supplied from the catalytic reaction device 73 to the processing chamber 7 through the fourth gas supply pipe 24. According to the method of the second example, water vapor can be generated without high temperature combustion as in the first example.

  FIG. 3 shows a third example of a method for generating water vapor (H2 O) by the water vapor generator 36. In the third example, pure water is generated by bubbling with an inert gas.

  In FIG. 3, the water vapor generator 36 has an N 2 gas source 74 for supplying, for example, nitrogen (N 2) gas, which is an inert gas, and a pure water container 76 for storing pure water 75. A gas supply pipe 77 connected to the N2 gas source 74 is communicated with the pure water container 76, and a tip portion as a gas outlet is submerged in the pure water 75 of the pure water container 76. The gas supply pipe 77 is provided with an on-off valve 78 and a flow rate controller 79 from the upstream side.

  A space 81 is left above the pure water container 76, and the fourth gas supply pipe 24 communicates with the space 81. A gas flow rate controller 34 is electrically connected to the on-off valve 78 and the flow rate controller 79 so that the flow rate of the N2 gas supplied from the N2 gas source 74 becomes a desired amount at a desired timing. It is configured to control. In the steam generator 36 of the third example, steam (H2 O) is generated by bubbling pure water in the pure water container 76 with nitrogen (N2) supplied from the N2 gas source 74. The generated water vapor (H 2 O) is supplied from the upper space of the pure water container 76 to the processing chamber 7 through the fourth gas supply pipe 24.

  Next, the operation of forming a thin film on the wafer 8 by the CVD method as one step of the semiconductor device manufacturing process using the processing furnace 1 according to the above configuration will be described with reference to FIG.

  In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the control device 52.

  When a predetermined number of wafers 8 are loaded into the boat 9 (wafer charging), the boat 9 is lifted by the boat elevator 10 and loaded into the processing chamber 7 (boat loading). In this state, the seal cap 14 hermetically closes the furnace port.

  The processing chamber 7 is evacuated by the evacuation device 42 so as to have a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 7 is detected by the pressure sensor 39, and the pressure adjusting device 41 feedback-controls the pressure in the processing chamber 7 based on the detection result.

  Further, the processing chamber 7 is heated by the heater 2 so as to reach a desired temperature. At this time, the power supply to the heater 2 is feedback-controlled based on the temperature information detected by the temperature sensor 48 so that the processing chamber 7 has a desired temperature distribution. Subsequently, the boat 9 is rotated by the rotation mechanism 44. The wafer 8 is rotated integrally with the boat 9, and the processing for the wafer 8 is made uniform.

  Next, process gases such as SiH2 Cl2 and NH3 are supplied from the first process gas supply source 27 and the second process gas supply source 30, and the process gas is the first gas flow rate controller 25 and the second gas flow rate. The controller 28 controls the flow rate to a desired level. The gas whose flow rate is controlled flows through the first gas supply pipe 21 and the second gas supply pipe 22 and is introduced into the processing chamber 7 from the first nozzle 15 and the second nozzle 16. The introduced gas rises in the processing chamber 7, turns back at the upper end opening of the internal reaction tube 5, flows down the cylindrical space 38, and is exhausted from the exhaust line 37. The processing gas comes into contact with the surface of the wafer 8 when passing through the processing chamber 7, and at this time, a thin film, for example, a silicon nitride film (Si3 N4 film) is formed on the surface of the wafer 8 by a thermal CVD reaction.

  When a preset processing time has elapsed, an inert gas is supplied from an inert gas supply source, the processing chamber 7 is replaced with an inert gas, and the pressure in the processing chamber 7 is returned to normal pressure. .

  The boat 9 is lowered (boat unloaded) by the boat elevator 10 through the seal cap 14.

  The processed wafer 8 after processing is discharged by a substrate transfer machine (not shown) (wafer discharge). The unloading of the processed wafer 8 is the reverse of the above description.

  As an example, the processing conditions for processing a wafer in the processing furnace of the present embodiment include, for example, a processing temperature of 600 ° C. to 800 ° C., a processing pressure of 2 to 2 in the formation of a Si 3 N 4 film. 200 Pa, gas type, gas supply flow rate (SiH2 Cl2: 5 to 500 sccm, NH3: 15 to 5000 sccm) are exemplified, and the wafer 8 is processed by keeping each processing condition constant at a certain value within each range. Is made.

  When the above film formation is repeated, a film adheres to the inner wall of the process tube 4 (the external reaction tube 6 and the internal reaction tube 5), but when the film thickness of the attached film reaches a predetermined thickness. The inside of the process tube 4 is cleaned.

  The cleaning process will be described below.

  An empty boat 9, that is, a boat 9 not loaded with wafers 8, is lifted by the boat elevator 10 and loaded into the processing chamber 7 (boat loading). In this state, the seal cap 14 hermetically closes the furnace port.

  The processing chamber 7 is evacuated by the evacuation device 42 so as to have a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 7 is detected by the pressure sensor 39, and the pressure adjusting device 41 is feedback-controlled based on the detected pressure so that the pressure in the processing chamber 7 becomes a predetermined pressure. The processing chamber 7 is heated by the heater 2. At this time, the temperature of the processing chamber 7 is detected by the temperature sensor 48, and the heater 2 is fed back by the temperature controller 49 based on temperature information detected so that the processing chamber 7 has a desired temperature and temperature distribution. Be controlled. Subsequently, the boat 9 is rotated by the rotation mechanism 44. The boat 9 need not be rotated.

  Next, a cleaning gas is supplied from the cleaning gas supply source 33, and a halogen-based gas, for example, NF3 gas, ClF3 gas or F2 gas, which is controlled by the third gas flow rate controller 31 to have a desired flow rate, The gas is introduced into the processing chamber 7 from the third nozzle 17 through the third gas supply pipe 23. The introduced halogen-based gas ascends in the processing chamber 7, flows down the cylindrical space 38 from the upper end opening of the internal reaction tube 5, and is exhausted from the exhaust line 37. In this way, the processing chamber 7 is cleaned. The halogen-based gas comes into contact with the inner wall of the process tube 4 and the film deposited on the boat 9 in the course of flowing through the processing chamber 7, and at this time, the film is removed (cleaned) by a thermochemical reaction.

  When a preset cleaning time has elapsed, an inert gas is supplied from an inert gas supply source, and the processing chamber 7 is replaced with the inert gas. The cleaning conditions include, for example, a cleaning temperature of 200 to 650 ° C., a cleaning pressure of 10 to 26600 Pa, a cleaning gas type (NF3 gas, ClF3 gas or F2 gas), and a cleaning gas supply flow rate of 500 to 5000 sccm. Cleaning is performed by keeping the conditions constant at certain values within the respective ranges.

  After cleaning, halogen species remain in the process tube 4. Residual halogen species cause the film formation to be hindered and also adversely affect the film quality. Therefore, in the present embodiment, residual halogen species are removed after cleaning. Hereinafter, the removal of residual halogen species will be described.

  The NH3 purge process will be described below.

  After the cleaning, the processing chamber 7 is replaced with an inert gas, and then the processing chamber 7 is evacuated by the vacuum evacuation device 42 so that a desired pressure (degree of vacuum) is obtained. At this time, the pressure in the processing chamber 7 is detected by the pressure sensor 39, and the pressure adjusting device 41 is feedback-controlled based on the detected pressure. Further, the processing chamber 7 is heated by the heater 2 so as to reach a desired temperature. At this time, the energization state of the heater 2 is feedback-controlled based on the detection result of the temperature sensor 48 so that the processing chamber 7 has a desired temperature distribution. Subsequently, the boat 9 is rotated by the rotation mechanism 44. The boat 9 may be continuously rotated from the time of cleaning or may not be rotated.

  Next, the NH 3 gas supplied from the second processing gas supply source 30 and controlled to have a desired flow rate by the second gas flow rate controller 28 flows through the gas supply pipe 22 and the second gas flow rate controller 28. It is introduced into the processing chamber 7 from the nozzle 16. The introduced NH3 gas rises in the processing chamber 7, flows down the cylindrical space 38, and is exhausted from the exhaust line 37. In this way, the NH3 purge of the processing chamber 7 is performed. When the NH3 gas passes through the processing chamber 7 and reacts with the halogen species remaining in the processing chamber 7, the halogen species are removed.

  Examples of NH3 purge conditions include a purge temperature of 200 to 750 ° C., a purge pressure of 100 to 50000 Pa, and an NH3 supply flow rate of 200 to 5000 sccm. Each purge condition is kept constant at a certain value within each range. By doing so, NH3 purge is performed.

  Next, the water vapor (H2 O) purge process will be described.

  After completion of the NH3 purge of the processing chamber 7, a water vapor (H2O) purge is performed. That is, the processing chamber 7 is evacuated by the evacuation device 42 so as to have a desired pressure (degree of vacuum). At this time, the pressure of the processing chamber 7 is feedback-controlled by the pressure adjusting device 41. The heater 2 is controlled to be heated by the temperature controller 49 so that the processing chamber 7 has a desired temperature and a desired temperature distribution. Subsequently, the boat 9 is rotated by the rotation mechanism 44. The boat 9 may be continuously rotated from the time of cleaning or may not be rotated.

  Next, steam (H 2 O) whose flow rate is controlled from the steam generator 36 is introduced into the processing chamber 7 from the fourth nozzle 18 through the fourth gas supply pipe 24. The introduced water vapor (H 2 O) rises in the processing chamber 7 and flows down the cylindrical space 38 and is exhausted from the exhaust line 37. In this way, the steam (H2 O) purge of the processing chamber 7 is performed. Steam (H2 O) is more reactive with halogen species than NH3 gas, and when steam (H2 O) passes through the processing chamber 7, it reacts with the halogen species that could not be removed by NH3 gas purge. The halogen species are more completely removed.

  The steam purge conditions include, for example, a purge temperature of 150 to 750 ° C., a purge pressure of 100 to 5000 Pa, and a steam (H 2 O) supply flow rate of 50 to 2000 sccm. Each purge condition is set to a certain value within each range. The water vapor (H2 O) purge is carried out by maintaining the pressure constant.

  When a preset purge time has elapsed, an inert gas is supplied from an inert gas supply source, and the processing chamber 7 is replaced with the inert gas.

  In addition, by performing the steam (H2 O) purge following the NH3 purge, the time for completely removing the halogen residual species by the NH3 purge can be shortened, and the conventional NH3 purge was performed for 1 to 4 hours. In the present invention, it was improved in 0.5 hours or less. In the present invention, the NH3 purge time may be 0.5 hours or less (for example, 30 minutes), and the water vapor (H2 O) purge time may be 0.5 hours or less (for example, 20 minutes). Even if the total purge time of H2 O) was reduced to 1 hour or less (for example, 50 minutes). Further, since the halogen residual species are completely removed, the CVD film formation rate is not reduced, and the film quality can be improved.

  Thereafter, pre-coating of the processing chamber 7 is performed. The pre-coating process is performed as follows.

  The processing chamber 7 is evacuated by the evacuation device 42 so as to have a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 7 is detected by the pressure sensor 39, and the pressure adjusting device 41 is feedback-controlled based on the detected pressure. Further, the processing chamber 7 is heated by the heater 2 so as to reach a desired temperature. At this time, the power supply to the heater 2 is feedback-controlled based on the temperature information detected by the temperature sensor 48 so that the processing chamber 7 has a desired temperature distribution. Subsequently, the boat 9 is rotated by the rotation mechanism 44. The boat 9 may be continuously rotated from the time of cleaning or may not be rotated.

  Next, the gas is supplied from the first process gas supply source 27 and the second process gas supply source 30 and is controlled by the first gas flow rate controller 25 and the second gas flow rate controller 28 so as to obtain a desired flow rate. The SiH2 Cl2 gas and NH3 gas are introduced into the processing chamber 7 from the first nozzle 15 and the second nozzle 16 through the first gas supply pipe 21 and the second gas supply pipe 22. The introduced SiH2 Cl2 gas and NH3 gas rise in the processing chamber 7, flow down the cylindrical space 38 and are exhausted from the exhaust line 37. SiH2 Cl2 gas and NH3 gas come into contact with the inner wall of the process tube 4 and the surface of the boat 9 when passing through the processing chamber 7. At this time, the inner wall of the process tube 4 and the boat 9 are brought into contact with the inner wall of the process tube 4 by the thermal CVD reaction. Then, the same thin film as the thin film formed in the film forming process, that is, a silicon nitride film (Si3 N4 film) is deposited (precoated).

  When a pre-coating time set in advance elapses, an inert gas is supplied from an inert gas supply source (not shown), the processing chamber 7 is replaced with the inert gas, and the pressure in the processing chamber 7 is increased. Return to normal pressure.

  In addition, by performing the NH3 purge and the water vapor (H2 O) purge, the halogen species are sufficiently removed, and as a result, the pre-coating time can be shortened. For example, the film thickness of the conventional pre-coating is 4000 mm and the pre-coating time is 4 hours. In the present invention, the film thickness of the pre-coating may be 2000 mm or less, and the pre-coating time can be shortened to 2 hours or less. .

  Thereafter, the seal cap 14 is lowered by the boat elevator 10 to open the furnace port portion, and the boat 9 is unloaded from the lower end of the manifold 12 to the outside of the process tube 4 (boat unloading). The

  After the pre-coating process is completed, the film forming process is resumed.

  As described above, as a method of supplying water vapor to the processing chamber 7 by the water vapor generating device 36, a method of supplying water vapor obtained by burning hydrogen and oxygen in the external combustion device 65 shown in FIG. There is a method of supplying water vapor obtained by catalytically burning hydrogen and oxygen in the catalytic reaction device 73, and a method of supplying water vapor obtained by bubbling the pure water 75 shown in FIG. 3 with a carrier gas. .

  The water vapor obtained by the external combustion device 65 and the catalytic reaction device 73 is water vapor having a humidity exceeding 100%, and since the concentration of the reactant is high, the collision probability between molecules is high, and therefore the reaction probability with the halogen species is also high. Since it is high, halogen species can be efficiently removed. Further, since water vapor can be stably supplied and pure water vapor can be supplied, contamination can be suppressed.

  Further, when supplying water vapor obtained by bubbling pure water, water vapor can be stably supplied, and the water vapor generating device 36 is a sealed system. Can be suppressed.

  Next, a second embodiment of the present invention will be described.

  The second embodiment differs from the first embodiment in that, in the second embodiment, instead of the water vapor (H2 O) purge step in the first embodiment, the atmosphere It is a point which performs an uptake process. In the air intake process, the seal cap 14 is lowered by the boat elevator 10 to open the furnace opening so that the outside air enters the processing chamber 7.

  Hereinafter, the air intake process will be described.

  After the NH3 purge of the processing chamber 7 is completed, an inert gas is supplied from an inert gas supply source, and the processing chamber 7 is replaced with the inert gas.

  Thereafter, the seal cap 14 is lowered by the boat elevator 10 to open the furnace port, and the empty boat 9 is unloaded from the lower end of the manifold 12 to the outside of the process tube 4 (boat unloading). Is done. After the boat unloading, the empty boat 9 is again lifted by the boat elevator 10 and carried into the processing chamber 7 (boat loading).

  During the boat unloading and boat loading described above, the furnace opening is opened, and the processing chamber 7 is in communication with a substrate transfer chamber (not shown) provided below the processing chamber 7.

  By exhausting the processing chamber 7 from the slow exhaust line 37b with the furnace port portion open, the atmosphere in the substrate transfer chamber can be taken into the processing chamber 7. The air taken into the processing chamber 7 moves up the processing chamber 7 and flows down the cylindrical space 38 and is exhausted from the exhaust line 37 and the slow exhaust line 37b. In this manner, an air intake process into the processing chamber 7 is performed. In the atmospheric uptake step, residual halogen species are removed by utilizing atmospheric humidity, that is, moisture (H2 O) contained in the atmosphere. The relative humidity in the atmosphere is preferably 20 to 80%.

  When the air intake process is completed, the furnace cap is closed by the seal cap 14, and the pre-coating process is continued (see FIG. 4).

  In the air intake process, the case where the empty boat 9 is again loaded after the boat unloading has been described. However, in the air intake process, the processing chamber 7 and the substrate transfer chamber are in communication with each other. The boat 9 may be maintained while being lowered halfway. In this way, the atmosphere in the substrate transfer chamber can be taken into the processing chamber 7 without completely removing the empty boat 9 from the processing chamber 7.

  In both cases of the first embodiment and the second embodiment, the process from the cleaning process to the pre-coating process may be performed in a state where an empty boat 9 is carried into the processing chamber 7, You may carry out without carrying the empty boat 9 in the process chamber 7. FIG. When these steps are performed without carrying the empty boat 9 into the processing chamber 7, the empty boat 9 is unloaded and the furnace port portion is airtightly closed by a furnace port shutter (not shown). In this case, in the air intake process in the second embodiment, the processing chamber 7 is exhausted from the slow exhaust line 37b with the furnace port shutter opened.

(Appendix)
The present invention includes the following embodiments.

  (Supplementary Note 1) A step of carrying a substrate into a processing chamber, a step of supplying a processing gas to the processing chamber to process the substrate, a step of unloading the processed substrate from the processing chamber, and a halogen in the processing chamber Supplying a system gas to clean the processing chamber; and supplying a water vapor generated by bubbling pure water into the processing chamber with an inert gas to remove residual halogen species in the processing chamber. A method for manufacturing a semiconductor device, comprising:

  (Appendix 2) A processing chamber for processing a substrate, a processing gas introduction pipe for introducing a processing gas into the processing chamber, a halogen-based gas introduction pipe for introducing a halogen-based gas as a cleaning gas into the processing chamber, and the processing chamber A steam inlet pipe for introducing steam into the steam inlet, a steam generator connected to the steam inlet pipe for generating steam by bubbling pure water with an inert gas, an exhaust pipe for exhausting the processing chamber, and the processing chamber And a control device for controlling so that residual halogen species in the processing chamber are removed by introducing water vapor from the water vapor generating device after introducing the halogen-based gas into the processing chamber and cleaning the processing chamber. A substrate processing apparatus.

  (Supplementary Note 3) A step of loading a substrate into a processing chamber, a step of supplying a processing gas to the processing chamber to process the substrate, a step of unloading the processed substrate from the processing chamber, and a halogen in the processing chamber Supplying the system gas to clean the processing chamber, and exhausting the processing chamber from an exhaust line provided in the processing chamber in a state where the processing chamber communicates with the outside of the processing chamber. And a step of taking outside air into the processing chamber and removing residual halogen species in the processing chamber.

  (Appendix 4) A processing chamber for processing a substrate, a processing gas introduction tube for introducing a processing gas into the processing chamber, a halogen-based gas introduction tube for introducing a halogen-based gas as a cleaning gas into the processing chamber, and the processing chamber An exhaust pipe for exhausting the process chamber, a lid for closing the process chamber, and after cleaning the process chamber by introducing a halogen-based gas into the process chamber, the lid for closing the process chamber is opened and the process is performed. A control device for controlling the outside of the processing chamber to be removed by removing the residual halogen species from the processing chamber by exhausting the processing chamber from the exhaust pipe in a state where the chamber is in communication with the outside of the processing chamber And a substrate processing apparatus.

It is a schematic sectional drawing of the processing furnace which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the water vapor generator used for this invention. It is explanatory drawing which shows the other example of the water vapor generator used for this invention. It is a flowchart of the process of the substrate processing apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing furnace 2 Heater 4 Process tube 7 Processing chamber 8 Wafer 9 Boat 10 Boat elevator 15 1st nozzle 16 2nd nozzle 17 3rd nozzle 18 4th nozzle 21 1st gas supply pipe 22 2nd gas supply pipe 23 3rd gas Supply pipe 24 Fourth gas supply pipe 25 First gas flow controller 27 First process gas supply source 28 Second gas flow controller 30 Second process gas supply source 31 Third gas flow controller 33 Cleaning gas supply source 36 Water vapor Generator 63 H2 gas source 64 O2 gas source 65 External combustion device 73 Catalytic reactor 74 N2 gas source 75 Pure water 76 Pure water container

Claims (2)

  A step of carrying the substrate into the processing chamber; a step of supplying the processing gas to the processing chamber to process the substrate; a step of unloading the processed substrate from the processing chamber; and supplying a halogen-based gas to the processing chamber And cleaning the processing chamber, and supplying the steam generated by burning oxygen gas and hydrogen gas into the processing chamber to remove residual halogen species in the processing chamber. A method for manufacturing a semiconductor device.   A processing chamber for processing a substrate, a processing gas introduction tube for introducing a processing gas into the processing chamber, a halogen-based gas introducing tube for introducing a halogen-based gas as a cleaning gas into the processing chamber, and water vapor introduced into the processing chamber A steam introduction pipe that is connected to the steam introduction pipe and that generates steam by burning oxygen gas and hydrogen gas; an exhaust pipe that exhausts the treatment chamber; and a halogen-based gas in the treatment chamber And a control device that controls to remove residual halogen species from the processing chamber by introducing water vapor from the water vapor generating device into the processing chamber after cleaning the processing chamber. A substrate processing apparatus.

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