JP2010050270A - Method for cleaning thin-film forming device, thin-film forming method, thin-film forming device, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method of a thin-film forming device for suppressing an occurrence of particles, and to provide a thin-film forming method, a thin-film forming device, and a program. <P>SOLUTION: When a silicon nitride is deposited in a reaction tube 2, various jigs or the like, the inside of the reaction tube 2 is set to the predetermined pressure and temperature, and NF<SB>3</SB>and H<SB>2</SB>as the predetermined amount of cleaning gas are supplied to the reaction tube 2 from a processing gas introduction tube 17, and the predetermined amount of N<SB>2</SB>as the diluent gas is supplied to the reaction tube 2. The supplied cleaning gas is heated in the reaction tube 2 and fluorine gas in the cleaning gas is activated, in other words, being in the state having a number of free atoms having reactive property, then supplied to an exhausting tube 5 from the reaction tube 2 through a top part 3 and the exhausting opening 4. This removes the silicon nitride adhered in the inside of a heat treatment device 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thin film forming apparatus cleaning method, thin film forming method, thin film forming apparatus, and program.

  In the manufacturing process of a semiconductor device, a thin film forming process for forming a thin film such as a silicon oxide film or a silicon nitride film on an object to be processed, for example, a semiconductor wafer, is performed by a process such as CVD (Chemical Vapor Deposition). In such a thin film forming process, for example, a thin film is formed on a semiconductor wafer as follows.

  First, the inside of the reaction tube of the heat treatment apparatus is heated to a predetermined load temperature, and a wafer boat containing a plurality of semiconductor wafers is loaded. Next, the inside of the reaction tube is heated to a predetermined processing temperature, the gas in the reaction tube is exhausted, and the inside of the reaction tube is reduced to a predetermined pressure. When the inside of the reaction tube is maintained at a predetermined temperature and pressure, a film forming gas is supplied into the reaction tube. When the film-forming gas is supplied into the reaction tube, for example, the film-forming gas causes a thermal reaction, the reaction product generated by the thermal reaction is deposited on the surface of the semiconductor wafer, and a thin film is formed on the surface of the semiconductor wafer. Is formed.

  By the way, the reaction product generated by the thin film forming process is deposited (attached) not only on the surface of the semiconductor wafer but also inside the heat treatment apparatus such as the inner wall of the reaction tube and various jigs. If the thin film forming process is continuously performed in a state where the reaction product is adhered in the heat treatment apparatus, the reaction product is eventually peeled off to easily generate particles. And when this particle adheres to a semiconductor wafer, the yield of the semiconductor device manufactured will be reduced.

  For this reason, after performing the thin film forming process a plurality of times, a cleaning gas, for example, a mixed gas of fluorine gas and halogen-containing acidic gas is supplied into the reaction tube heated to a predetermined temperature by the heater, and the inner wall of the reaction tube, etc. A cleaning method for a heat treatment apparatus that removes (dry etching) reaction products adhering in the heat treatment apparatus has been proposed (see, for example, Patent Document 1).

JP-A-3-293726

  By the way, if the cleaning gas is supplied into the reaction tube, the cleaning gas may damage the reaction tube or the wafer boat. When the reaction tube is damaged, there is a problem that powder (quartz powder) is peeled off from the reaction tube and causes generation of particles. Moreover, there is a problem that the surface area of the reaction tube or the like increases, and for example, the film formation rate (deposition) decreases.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a thin film forming apparatus cleaning method, thin film forming method, thin film forming apparatus, and program capable of suppressing the generation of particles.
It is another object of the present invention to provide a thin film forming apparatus cleaning method, thin film forming method, thin film forming apparatus, and program capable of suppressing a decrease in deposition rate.

In order to achieve the above object, a method for cleaning a thin film forming apparatus according to the first aspect of the present invention comprises:
A method of cleaning a thin film forming apparatus for supplying a processing gas into a reaction chamber of a thin film forming apparatus to form a thin film on an object to be processed and then removing deposits attached to the inside of the apparatus,
A heating step of heating the reaction chamber to a predetermined temperature;
A cleaning step of cleaning the inside of the apparatus by removing the deposits by supplying a cleaning gas containing a perfluoro compound gas and a hydrogen-containing gas into the reaction chamber heated to a predetermined temperature by the heating step; ,
It is characterized by comprising.

The perfluoro compound gas is, for example, NF ₃ , CF ₄ , C ₂ F ₆ , C ₅ F ₈ , or SF ₆ , and the gas containing hydrogen is, for example, H ₂ , H ₂ O, or H ₂ O ₂ .
In the heating step, for example, the reaction chamber is heated to 300 ° C. to 500 ° C.

In the cleaning step, for example, the cleaning gas is diluted with a diluent gas, and the diluted cleaning gas is supplied into the reaction chamber.
For example, an inert gas is used as the dilution gas.
The thin film formed on the object to be processed is, for example, a silicon oxide film, a silicon nitride film, or a polysilicon film.

The thin film forming method according to the second aspect of the present invention is:
A cleaning step of cleaning the thin film forming apparatus by the cleaning method of the thin film forming apparatus according to the first aspect of the present invention;
A film forming step of heating the reaction chamber containing the object to be processed to a predetermined temperature, supplying a processing gas into the heated reaction chamber, and forming a thin film on the object to be processed;
It is characterized by comprising.

A thin film forming apparatus according to a third aspect of the present invention is:
A thin film forming apparatus that forms a thin film on a target object by supplying a processing gas into a reaction chamber that houses the target object,
Heating means for heating the reaction chamber to a predetermined temperature;
Cleaning means for removing the deposits and cleaning the inside of the apparatus by supplying a cleaning gas containing a perfluoro compound gas and a gas containing hydrogen into the reaction chamber heated to a predetermined temperature by the heating means;
It is characterized by comprising.

The program according to the fourth aspect of the present invention is:
A program that functions as a thin film forming apparatus that supplies a processing gas into a reaction chamber containing a target object to form a thin film on the target object,
Computer
Heating means for heating the reaction chamber to a predetermined temperature;
A cleaning means for removing the deposits and cleaning the inside of the apparatus by supplying a cleaning gas containing a perfluoro compound gas and a hydrogen-containing gas into the reaction chamber heated to a predetermined temperature by the heating means;
It is made to function as.

  According to the present invention, the generation of particles can be suppressed.

  The thin film forming apparatus cleaning method, thin film forming method, thin film forming apparatus, and program of the present invention will be described below. In the present embodiment, the present invention will be described by taking as an example the case where the batch type vertical heat treatment apparatus 1 shown in FIG. 1 is used as the thin film forming apparatus of the present invention.

  As shown in FIG. 1, the heat treatment apparatus 1 includes a reaction tube 2 that forms a reaction chamber. The reaction tube 2 is formed in, for example, a substantially cylindrical shape whose longitudinal direction is directed in the vertical direction. The reaction tube 2 is made of a material excellent in heat resistance and corrosion resistance, for example, quartz.

  At the upper end of the reaction tube 2 is provided a top portion 3 formed in a substantially conical shape so as to reduce in diameter toward the upper end side. An exhaust port 4 for exhausting the gas in the reaction tube 2 is provided at the center of the top 3, and an exhaust tube 5 is connected to the exhaust port 4 in an airtight manner. The exhaust pipe 5 is provided with a pressure adjusting mechanism such as a valve (not shown) and a vacuum pump 127 described later, and controls the inside of the reaction pipe 2 to a desired pressure (degree of vacuum).

  A lid 6 is disposed below the reaction tube 2. The lid 6 is made of a material excellent in heat resistance and corrosion resistance, for example, quartz. The lid 6 is configured to be movable up and down by a boat elevator 128 described later. When the lid 6 is raised by the boat elevator 128, the lower side (furnace port portion) of the reaction tube 2 is closed, and when the lid 6 is lowered by the boat elevator 128, the lower side (furnace port portion) of the reaction tube 2. Is opened.

  A heat insulating cylinder 7 is provided on the top of the lid 6. The heat retaining cylinder 7 includes a planar heater 8 made of a resistance heating element that prevents a temperature drop in the reaction tube 2 due to heat radiation from the furnace port portion of the reaction tube 2, and the heater 8 from a top surface of the lid 6 to a predetermined amount. It is mainly comprised from the cylindrical support body 9 supported to height.

  A rotary table 10 is provided above the heat insulating cylinder 7. The turntable 10 functions as a mounting table for rotatably mounting an object to be processed, for example, a wafer boat 11 that accommodates a semiconductor wafer W. Specifically, a rotary column 12 is provided at the lower part of the rotary table 10, and the rotary column 12 is connected to a rotary mechanism 13 that rotates through the central portion of the heater 8 and rotates the rotary table 10. The rotation mechanism 13 is mainly composed of a motor (not shown) and a rotation introduction portion 15 including a rotation shaft 14 that is penetrated and introduced in an airtight manner from the lower surface side to the upper surface side of the lid body 6. The rotary shaft 14 is connected to the rotary column 12 of the rotary table 10 and transmits the rotational force of the motor to the rotary table 10 via the rotary column 12. For this reason, when the rotating shaft 14 is rotated by the motor of the rotating mechanism 13, the rotating force of the rotating shaft 14 is transmitted to the rotating column 12 and the rotating table 10 rotates.

  A wafer boat 11 is placed on the turntable 10. The wafer boat 11 is configured to accommodate a plurality of semiconductor wafers W at a predetermined interval in the vertical direction. For this reason, when the turntable 10 is rotated, the wafer boat 11 is rotated, and the semiconductor wafer W accommodated in the wafer boat 11 is rotated by this rotation. The wafer boat 11 is made of a material excellent in heat resistance and corrosion resistance, for example, quartz.

  Further, around the reaction tube 2, for example, a temperature raising heater 16 made of a resistance heating element is provided so as to surround the reaction tube 2. The inside of the reaction tube 2 is heated to a predetermined temperature by the temperature raising heater 16, and as a result, the semiconductor wafer W is heated to a predetermined temperature.

  A processing gas introduction tube 17 for introducing a processing gas (for example, a film forming gas or a cleaning gas) into the reaction tube 2 is inserted in a side surface near the lower end of the reaction tube 2. The processing gas introduction pipe 17 is connected to a processing gas supply source (not shown) via a mass flow controller (MFC) 125 described later.

As the deposition gas, a gas corresponding to the type of thin film formed on the semiconductor wafer W, for example, a silicon nitride film, a silicon oxide film, or a polysilicon film is used. For example, when a silicon nitride film is formed on the semiconductor wafer W, hexachlorodisilane (HCD: Si ₂ Cl ₆ ) and ammonia (NH ₃ ) or dichlorosilane (DCS: SiH ₂ Cl ₂ ) are used as film forming gases. ) And gases such as ammonia are used.

As the cleaning gas, for example, perfluoro compound gas such as NF ₃ , CF ₄ , C ₂ F ₆ , C ₅ F ₈ , SF ₆ , hydrogen (H ₂ ), water (H ₂ O), hydrogen peroxide ( A gas containing hydrogen such as H ₂ O ₂ ) is used.

  In FIG. 1, only one processing gas introduction pipe 17 is drawn, but in the present embodiment, a plurality of processing gas introduction pipes 17 are inserted depending on the type of gas introduced into the reaction pipe 2. Yes.

  A purge gas supply pipe 18 is inserted through the side surface near the lower end of the reaction tube 2. A purge gas supply source (not shown) is connected to the purge gas supply pipe 18, and a desired amount of purge gas, for example, nitrogen gas, is supplied from the purge gas supply source through the purge gas supply pipe 18 into the reaction tube 2.

  Moreover, the heat processing apparatus 1 is provided with the control part 100 which controls each part of an apparatus. FIG. 2 shows the configuration of the control unit 100. As shown in FIG. 2, the control unit 100 includes an operation panel 121, a temperature sensor (group) 122, a pressure gauge (group) 123, a heater controller 124, an MFC control unit 125, a valve control unit 126, a vacuum pump 127, a boat An elevator 128 or the like is connected.

  The operation panel 121 includes a display screen and operation buttons, transmits an operation instruction of the operator to the control unit 100, and displays various information from the control unit 100 on the display screen.

The temperature sensor (group) 122 measures the temperature of each part in the reaction tube 2, the exhaust pipe 5, the processing gas introduction pipe 17, etc., and notifies the control unit 100 of the measured values.
The pressure gauge (group) 123 measures the pressure of each part in the reaction tube 2, the exhaust pipe 5, the processing gas introduction pipe 17, etc., and notifies the control unit 100 of the measured values.

  The heater controller 124 is for individually controlling the heater 8 and the heater 16 for raising temperature. In response to an instruction from the control unit 100, the heater controller 124 energizes them to heat them. Are measured individually and notified to the control unit 100.

  The MFC control unit 125 controls a mass flow controller (MFC) (not shown) provided in the processing gas introduction pipe 17 and the purge gas supply pipe 18 so that the flow rate of the gas flowing through them is controlled by the control unit 100. At the same time, the flow rate of the gas that actually flows is measured and notified to the control unit 100.

  The valve control unit 126 controls the opening degree of the valve disposed in each pipe to a value instructed by the control unit 100. The vacuum pump 127 is connected to the exhaust pipe 5 and exhausts the gas in the reaction pipe 2.

  The boat elevator 128 lifts the lid 6, loads the wafer boat 11 (semiconductor wafer W) placed on the rotary table 10 into the reaction tube 2, and rotates the lid 6 to lower the lid 6. The wafer boat 11 (semiconductor wafer W) placed on the table 10 is unloaded from the reaction tube 2.

  The control unit 100 includes a recipe storage unit 111, a ROM 112, a RAM 113, an I / O port 114, a CPU 115, and a bus 116 that interconnects them.

  The recipe storage unit 111 stores a setup recipe and a plurality of process recipes. At the beginning of the manufacture of the heat treatment apparatus 1, only the setup recipe is stored. The setup recipe is executed when generating a thermal model or the like corresponding to each heat treatment apparatus. The process recipe is a recipe prepared for each heat treatment (process) actually performed by the user. For example, each part from loading of the semiconductor wafer W to the reaction tube 2 until unloading of the processed wafer W is performed. The temperature change, the pressure change in the reaction tube 2, the start and stop timing and supply amount of the process gas supply are defined.

The ROM 112 is a recording medium that includes an EEPROM, a flash memory, a hard disk, and the like, and stores an operation program of the CPU 115 and the like.
The RAM 113 functions as a work area for the CPU 115.

  The I / O port 114 is connected to the operation panel 121, temperature sensor 122, pressure gauge 123, heater controller 124, MFC control unit 125, valve control unit 126, vacuum pump 127, boat elevator 128, etc. Control the output.

A CPU (Central Processing Unit) 115 constitutes the center of the control unit 100, executes a control program stored in the ROM 112, and stores recipes (for process) stored in the recipe storage unit 111 in accordance with instructions from the operation panel 121. The operation of the heat treatment apparatus 1 is controlled along the recipe. That is, the CPU 115 includes the temperature sensor (group) 122, the pressure gauge (group) 123, the MFC control unit 125, and the like in the reaction tube 2, the processing gas introduction tube 17, and the temperature and pressure of each unit in the exhaust tube 5. Based on the measurement data, control signals and the like are output to the heater controller 124, the MFC control unit 125, the valve control unit 126, the vacuum pump 127, and the like, and the respective units are controlled to follow the process recipe. .
The bus 116 transmits information between the units.

Next, a thin film forming method including a cleaning method for the heat treatment apparatus 1 configured as described above will be described. FIG. 3 shows a recipe for explaining the thin film forming method of the present embodiment. In the present embodiment, as shown in FIG. 3, a silicon nitride film having a predetermined thickness is formed on the semiconductor wafer W using HCD and ammonia as the film forming gas (film forming process), and NF is used as the cleaning gas. _The present invention will be described by taking as an example a cleaning method (cleaning process) that uses ₃ and H ₂ to remove silicon nitride adhering to the inside of the heat treatment apparatus 1 by a film forming process.

  In the following description, the operation of each part constituting the heat treatment apparatus 1 is controlled by the control unit 100 (CPU 115). Further, as described above, the controller 100 (CPU 115) is controlled by the heater controller 124 (heater 8 and the temperature raising heater 16) and the MFC controller 125 for the temperature, pressure, gas flow rate, etc. in the reaction tube 2 in each process. By controlling the valve control unit 126, the vacuum pump 127, etc., the conditions according to the recipe shown in FIG.

  First, as shown in FIG. 3A, the inside of the reaction tube 2 is set to a predetermined temperature. Further, as shown in FIG. 3C, a wafer in which a predetermined amount of nitrogen is supplied from the purge gas supply pipe 18 into the reaction pipe 2 and a semiconductor wafer W as an object to be processed for forming a silicon nitride film is accommodated. The boat 11 is placed on the lid body 6. Then, the lid 6 is raised by the boat elevator 128, and the semiconductor wafer W (wafer boat 11) is loaded into the reaction tube 2 (loading step).

  Next, as shown in FIG. 3 (c), a predetermined amount of nitrogen is supplied from the purge gas supply pipe 18 into the reaction tube 2, and the reaction tube 2 is given a predetermined temperature, for example, as shown in FIG. 3 (a). Set to 600 ° C. Further, the gas in the reaction tube 2 is discharged, and the reaction tube 2 is depressurized to a predetermined pressure, for example, 65.5 Pa (0.5 Torr) as shown in FIG. And the inside of the reaction tube 2 is stabilized at this temperature and pressure (stabilization step).

When the inside of the reaction tube 2 is stabilized at a predetermined pressure and temperature, the supply of nitrogen from the purge gas supply tube 18 is stopped. Subsequently, a predetermined amount of film forming gas is introduced into the reaction tube 2 from the processing gas introduction tube 17. In the present embodiment, for example, DCS is supplied at 0.1 liter / min as shown in FIG. 3 (d), and NH ₃ is supplied at 1.0 liter / min as shown in FIG. 3 (e). To do. When the film forming gas is introduced into the reaction tube 2, the film forming gas is heated in the reaction tube 2 to form a silicon nitride film on the surface of the semiconductor wafer W (film forming step).

  When a silicon nitride film having a predetermined thickness is formed on the surface of the semiconductor wafer W, the introduction of the deposition gas from the processing gas introduction pipe 17 is stopped. Then, the gas in the reaction tube 2 is discharged, and as shown in FIG. 3C, a predetermined amount of nitrogen is supplied from the purge gas supply tube 18, and the gas in the reaction tube 2 is discharged to the exhaust tube 5. (Purge process). In addition, in order to discharge | emit the gas in the reaction tube 2 reliably, it is preferable to repeat discharge | emission of the gas in the reaction tube 2, and supply of nitrogen gas in multiple times.

  Subsequently, as shown in FIG. 3 (c), a predetermined amount of nitrogen is supplied into the reaction tube 2 from the purge gas supply pipe 18, and the pressure in the reaction tube 2 is kept constant as shown in FIG. 3 (b). Return to pressure. Further, as shown in FIG. 3A, the inside of the reaction tube 2 is set to a predetermined temperature. Then, the lid 6 is lowered by the boat elevator 128 to unload the semiconductor wafer W (wafer boat 11) from the reaction tube 2 (unload process). Thereby, the film forming process for forming the silicon nitride film is completed.

  When the film forming process as described above is performed a plurality of times, silicon nitride generated by the film forming process is deposited (attached) not only on the surface of the semiconductor wafer W but also in the reaction tube 2 and various jigs. . For this reason, after performing the film forming process a predetermined number of times, a cleaning process is performed as a cleaning method for the heat treatment apparatus 1 for removing silicon nitride adhering to the inside of the heat treatment apparatus 1.

  First, as shown in FIG. 3C, after supplying a predetermined amount of nitrogen from the purge gas supply pipe 18 into the reaction tube 2, the wafer boat 11 in which the semiconductor wafer W is not accommodated is placed on the lid body 6. Then, the reaction tube 2 is sealed by raising the lid 6 by the boat elevator 128. Next, a predetermined amount of nitrogen is supplied from the purge gas supply pipe 18 into the reaction tube 2, and the inside of the reaction tube 2 is set to 300 ° C. to 500 ° C., for example, 400 ° C. as shown in FIG. . Further, the gas in the reaction tube 2 is discharged, and the reaction tube 2 is depressurized to a predetermined pressure, for example, 53200 Pa (400 Torr) as shown in FIG. And the inside of the reaction tube 2 is stabilized at this temperature and pressure (stabilization step).

When the inside of the reaction tube 2 is stabilized at a predetermined pressure and temperature, the supply of nitrogen from the purge gas supply tube 18 is stopped. Subsequently, a predetermined amount of cleaning gas is introduced into the reaction tube 2 from the processing gas introduction tube 17. In the present embodiment, for example, NF ₃ and H ₂ are supplied into the reaction tube 2 as shown in FIGS. 3 (f) and 3 (g) and diluted as shown in FIG. 3 (c). A predetermined amount of nitrogen (N ₂ ) as a gas is supplied into the reaction tube 2. The introduced cleaning gas is heated in the reaction tube 2, and the fluorine gas in the cleaning gas is activated, that is, has a state of having many free atoms having reactivity. Further, since the cleaning gas contains a gas (H ₂ ) containing hydrogen, activation of the fluorine gas is promoted. Then, cleaning gas containing activated fluorine gas is supplied from the reaction tube 2 to the exhaust pipe 5 through the top 3 and the exhaust port 4, thereby contacting the silicon nitride adhering to the inside of the heat treatment apparatus 1. The silicon nitride is etched. Thereby, the silicon nitride adhering to the inside of the heat treatment apparatus 1 is removed (cleaning step).

  Here, the temperature in the reaction tube 2 in the washing step is preferably set to 300 ° C to 500 ° C. This is because if the temperature in the reaction tube 2 is higher than 500 ° C., the quartz and SiC constituting the reaction tube 2 and the jig may be deteriorated. Further, when the temperature in the reaction tube 2 is lower than 300 ° C., the cleaning gas is not easily activated, and the silicon nitride may not be easily etched by the cleaning gas.

  The cleaning gas preferably contains nitrogen as a dilution gas. By diluting the cleaning gas with nitrogen gas, the cleaning process time can be easily set. This is because the reactivity increases if the cleaning gas does not contain nitrogen, so that the time for the cleaning process must be set strictly, and the time for the cleaning process becomes difficult to set. Furthermore, it is because it is preferable to dilute the cleaning gas with nitrogen also from an economical aspect.

  When the silicon nitride adhering to the inside of the heat treatment apparatus 1 is removed, the supply of the cleaning gas from the processing gas introduction pipe 17 is stopped. Then, the gas in the reaction tube 2 is discharged, and as shown in FIG. 3C, a predetermined amount of nitrogen is supplied from the purge gas supply tube 18, and the gas in the reaction tube 2 is discharged to the exhaust tube 5. (Purge process). In addition, in order to discharge | emit the gas in the reaction tube 2 reliably, it is preferable to repeat discharge | emission of the gas in the reaction tube 2, and supply of nitrogen gas in multiple times.

  Finally, as shown in FIG. 3C, a predetermined amount of nitrogen is supplied from the purge gas supply pipe 18, and the pressure in the reaction pipe 2 is returned to normal pressure (normal pressure return step). Then, the lid body 6 is lowered by the boat elevator 128, the lid body 7 is lowered by the boat elevator 8, and the wafer boat 11 containing the semiconductor wafers W is placed on the lid body 6. It is possible to perform a film forming process for forming a silicon nitride film on the semiconductor wafer W in a state where no silicon nitride is adhered to the inside.

As described above, according to the present embodiment, since the gas containing NF ₃ and H ₂ is used as the cleaning gas, silicon nitride adhering to the inside of the heat treatment apparatus 1 can be removed. For this reason, generation | occurrence | production of a particle can be suppressed. Further, it is possible to suppress a decrease in deposition rate.

  In addition, this invention is not restricted to said embodiment, A various deformation | transformation and application are possible. Hereinafter, other embodiments applicable to the present invention will be described.

In the above embodiment, the present invention has been described by taking as an example the case where a gas containing NF ₃ and H ₂ is used as the cleaning gas. However, NF ₃ , CF ₄ , C ₂ F ₆ , C ₅ F _{8 are used.} The perfluoro compound gas such as SF ₆ may contain a gas containing hydrogen such as hydrogen (H ₂ ), water (H ₂ O), and hydrogen peroxide (H ₂ O ₂ ). Also in these cases, silicon nitride adhering to the inside of the heat treatment apparatus 1 can be removed.

  In the present embodiment, the present invention has been described by taking as an example the case of removing silicon nitride adhering to the inside of the heat treatment apparatus 1, but the deposits adhering to the inside of the heat treatment apparatus 1 are not limited to silicon nitride. For example, silicon oxide or polysilicon may be used. Moreover, such deposits are not limited to reaction products, and may be reaction byproducts.

  In the present embodiment, the present invention has been described by taking as an example the case where the cleaning gas contains nitrogen as a diluent gas. However, the cleaning gas may not include the diluent gas. However, it is preferable to include the dilution gas in the cleaning gas because the cleaning process time can be easily set by including the dilution gas. The diluent gas is preferably an inert gas, and in addition to nitrogen gas, for example, helium gas (He), neon gas (Ne), and argon gas (Ar) can be applied.

  In the present embodiment, the present invention has been described by taking as an example the case where the pressure inside the reaction tube 2 is set to 53200 Pa (400 Torr) and the inside of the heat treatment apparatus 1 is cleaned, but the pressure inside the reaction tube 2 is It is not limited to this. The frequency of cleaning may be performed every several film formation processes, but may be performed every film formation process, for example. When cleaning is performed for each film forming process, the lifetime of the material inside the apparatus composed of quartz, SiC, or the like can be further extended.

  In the above embodiment, the present invention has been described by taking as an example the case where a silicon nitride film is formed by using HCD and ammonia as the film forming gas and setting the temperature in the reaction tube 2 to 600 ° C. The temperature in the reaction tube 2 is preferably set so as to be in a range corresponding to the type of film forming gas to be used. For example, when DCS and ammonia are used as the film forming gas, 600 ° C. to 800 ° C. It is preferable to set to ° C.

  In the above embodiment, the present invention has been described by taking the case where the inside of the reaction tube 2 is set to 65.5 Pa (0.5 Torr) as an example, but the pressure in the reaction tube 2 is low, for example, 1.33 Pa (0. 01 Torr) to 1330 Pa (10 Torr), more preferably 13.3 Pa (0.1 Torr) to 133 Pa (1 Torr).

  In the above embodiment, the present invention has been described by taking the case of a batch type heat treatment apparatus having a single tube structure as the heat treatment apparatus. For example, a double tube structure in which the reaction tube 2 is composed of an inner tube and an outer tube. It is also possible to apply the present invention to the batch type vertical heat treatment apparatus. In addition, the present invention can be applied to a single wafer heat treatment apparatus.

  The control unit 100 according to the embodiment of the present invention can be realized using a normal computer system, not a dedicated system. For example, the control unit 100 that executes the above-described processing is configured by installing the program from a recording medium (such as a flexible disk or a CD-ROM) that stores the program for executing the above-described processing in a general-purpose computer. be able to.

  The means for supplying these programs is arbitrary. In addition to being able to be supplied via a predetermined recording medium as described above, for example, it may be supplied via a communication line, a communication network, a communication system, or the like. In this case, for example, the program may be posted on a bulletin board (BBS) of a communication network and provided by superimposing it on a carrier wave via the network. Then, the above-described processing can be executed by starting the program thus provided and executing it in the same manner as other application programs under the control of the OS.

It is a figure which shows the heat processing apparatus of embodiment of this invention. It is a figure which shows the structure of the control part of FIG. It is the figure which showed the recipe explaining the formation method of the silicon nitride film of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat processing apparatus 2 Reaction tube 3 Top part 4 Exhaust port 5 Exhaust pipe 6 Lid body 7 Heat insulation cylinder 8 Heater 9 Support body 10 Rotary table 11 Wafer boat 12 Rotation support | pillar 13 Rotation mechanism 14 Rotation shaft 15 Rotation introduction part 16 Heating heater 17 Process gas introduction pipe 18 Purge gas supply pipe 100 Control unit 111 Recipe storage unit 112 ROM
113 RAM
114 I / O port 115 CPU
116 Bus 121 Operation Panel 122 Temperature Sensor 123 Pressure Gauge 124 Heater Controller 125 MFC Control Unit 126 Valve Control Unit 127 Vacuum Pump 128 Boat Elevator W Semiconductor Wafer

Claims (9)

A method of cleaning a thin film forming apparatus for supplying a processing gas into a reaction chamber of a thin film forming apparatus to form a thin film on an object to be processed and then removing deposits attached to the inside of the apparatus,
A heating step of heating the reaction chamber to a predetermined temperature;
A cleaning step of cleaning the inside of the apparatus by removing the deposits by supplying a cleaning gas containing a perfluoro compound gas and a hydrogen-containing gas into the reaction chamber heated to a predetermined temperature by the heating step; ,
A method for cleaning a thin film forming apparatus, comprising: The perfluoro compound gas is NF ₃ , CF ₄ , C ₂ F ₆ , C ₅ F ₈ , or SF ₆ , and the gas containing hydrogen is H ₂ , H ₂ O, or H ₂ O ₂ . The method for cleaning a thin film forming apparatus according to claim 1.   The method for cleaning a thin film forming apparatus according to claim 1, wherein, in the heating step, the reaction chamber is heated to 300 ° C. to 500 ° C. 3.   4. The thin film forming apparatus according to claim 1, wherein in the cleaning step, the cleaning gas is diluted with a diluent gas, and the diluted cleaning gas is supplied into the reaction chamber. 5. Cleaning method.   The cleaning method for a thin film forming apparatus according to claim 4, wherein an inert gas is used as the dilution gas.   6. The thin film forming apparatus cleaning method according to claim 1, wherein the thin film formed on the object to be processed is a silicon oxide film, a silicon nitride film, or a polysilicon film. A cleaning step of cleaning the thin film forming apparatus by the cleaning method of the thin film forming apparatus according to any one of claims 1 to 6;
A film forming step of heating the reaction chamber containing the object to be processed to a predetermined temperature, supplying a processing gas into the heated reaction chamber, and forming a thin film on the object to be processed;
A thin film forming method characterized by comprising: A thin film forming apparatus that forms a thin film on a target object by supplying a processing gas into a reaction chamber that houses the target object,
Heating means for heating the reaction chamber to a predetermined temperature;
Cleaning means for removing the deposits and cleaning the inside of the apparatus by supplying a cleaning gas containing a perfluoro compound gas and a gas containing hydrogen into the reaction chamber heated to a predetermined temperature by the heating means;
A thin film forming apparatus comprising: A program that functions as a thin film forming apparatus that supplies a processing gas into a reaction chamber containing a target object to form a thin film on the target object,
Computer
Heating means for heating the reaction chamber to a predetermined temperature;
A cleaning means for removing the deposits and cleaning the inside of the apparatus by supplying a cleaning gas containing a perfluoro compound gas and a hydrogen-containing gas into the reaction chamber heated to a predetermined temperature by the heating means;
Program to function as.

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