JP2007109865A - Substrate processing apparatus and semiconductor device manufacturing method - Google Patents

Abstract

A substrate processing apparatus capable of reducing the amount of a cleaning solvent used for cleaning a liquid source supply pipe and increasing the cleaning capability of the liquid source supply pipe.
A substrate processing apparatus includes a processing container for processing a substrate, a vaporizer for vaporizing a liquid material, a liquid material supply pipe for supplying the liquid material to the vaporizer, and a gas obtained by vaporizing the liquid material. Is supplied to the processing vessel 4, at least one discharge pipe for discharging the fluid in the liquid source supply pipe 13 provided in the liquid source supply pipe 13, and conductance of the discharge pipe provided in the discharge pipe And a solvent supply mechanism 29 for supplying a cleaning solvent into the liquid raw material supply pipe 13.
[Selection] Figure 1

Description

  The present invention relates to a substrate processing apparatus for processing a substrate using a liquid source and a method for manufacturing a semiconductor device, and more particularly to an improved maintenance of a liquid source supply mechanism.

  In recent years, with the high integration of semiconductors, there is a need for a technique for forming a film with high step coverage in holes and grooves having a high aspect ratio. Therefore, a film forming method using chemical vapor deposition (CVD) is increasingly selected as a film forming method used in the substrate processing apparatus. In general, CVD has better step coverage than physical vapor deposition (PVD) such as vapor deposition and sputtering. In addition, the raw material can be used as a gas by chemically synthesizing a normal solid element, or it can be used after being synthesized into a liquid / solid which is easily gasified and then gasified. As the raw material, liquid is easier to handle than solid, so that liquid raw material is used.

  FIG. 3 is a schematic view showing a conventional single wafer CVD apparatus using such a liquid material.

  A raw material gas supply pipe 17 for supplying a raw material gas is connected to the processing container 4. Further, an inert gas supply pipe 12 for supplying an inert gas and an oxidizing gas supply pipe 16 for supplying an oxidizing gas are connected to the processing container 4.

In addition, the source gas supply pipe 17 is provided with a vent pipe 11. An exhaust device 5 b is connected to the vent pipe 11. Further, the vaporizer 3 for vaporizing the liquid raw material is connected to the raw material gas supply pipe 17. A liquid raw material supply pipe 13 is connected to the vaporizer 3, and the liquid raw material supply pipe 13 is connected to the raw material container 1 via a liquid mass flow controller (MFC) 2.
The raw material gas supply line 17 and the liquid raw material supply line 13 constitute a raw material supply line.

  The raw material container 1 is connected to a pressurized gas supply pipe 15 a that supplies a pressurized gas for extruding the liquid raw material in the raw material container to the liquid raw material supply pipe 13. A solvent supply pipe 18 is connected to the liquid source supply pipe 13. A solvent container 19 is connected to the solvent supply pipe 18. Connected to the solvent container 19 is a pressurized gas supply pipe 15 b for supplying a pressurized gas for pushing the cleaning solvent in the solvent container 19 to the solvent supply pipe 18.

  Further, a discharge pipe 25 is connected to the vent pipe 11. The discharge pipe 25 is connected to the liquid raw material supply pipe 13.

In such a configuration, when a film is formed on the substrate, a pressurized gas such as N ₂ is supplied to the raw material container 1, the liquid raw material is extruded into the liquid raw material supply pipe 13, and the extruded liquid raw material is vaporized by the vaporizer 3. It is vaporized and supplied into the processing container 4 as a raw material gas through the raw material gas supply pipe 17. After being activated, the oxidizing gas is supplied to the processing container 4 through the oxidizing gas supply pipe 16.

   By the way, when liquid raw material is used as raw material, it is necessary to replace or change the raw material, to replace part of the supply pipe or parts (liquid MFC, vaporizer, etc.), or to replace the entire pipe, before removing (after installation), etc. In many cases, maintenance such as cleaning the liquid material supply pipe is required. This is because the liquid raw material has physical properties such as weakness against oxidation and deterioration when exposed to moisture. Cleaning of the liquid raw material supply pipe is required not only when cleaning the liquid raw material supply pipe but also when exchanging the raw material container.

  A cleaning solvent is used for cleaning the liquid raw material supply pipe, but if this cleaning solvent is different from the raw material solvent, or if no solvent is used for the raw material, the cleaning solvent is not required when supplying the raw material. Therefore, in order to supply the raw material to the liquid raw material supply pipe again after cleaning, the cleaning solvent must be removed so as not to remain in the liquid raw material supply pipe. When the raw material deteriorates and deteriorates and solidifies, not only the liquid raw material supply pipe is washed, but also the liquid raw material supply pipe may be replaced, and maintenance of the liquid raw material supply pipe is important.

Conventionally, cleaning of the liquid raw material supply pipe is performed by supplying a pressure gas such as N ₂ to the solvent container 19, pushing the cleaning solvent in the solvent container 19 into the solvent supply pipe 18, and supplying the pushed cleaning solvent to the liquid raw material. While being supplied into the pipe 13, the liquid source supply pipe 13 is discharged from the discharge pipe 25 connected to the liquid source supply pipe 13 to clean the inside of the liquid source supply pipe 13. After the cleaning, the supply of the cleaning solvent into the liquid source supply pipe 13 is stopped, and the cleaning solvent is discharged from the liquid source supply pipe 13 through the discharge pipe 25.

However, the conventional substrate processing apparatus described above has the following problems.
Since the cleaning solvent pushed out to the liquid source supply pipe is discharged from the normal discharge pipe where it is difficult to adjust the conductance, the amount of the cleaning solvent used is large.
In addition, since the cleaning solvent pushed out to the liquid source supply pipe is discharged from the normal discharge pipe whose conductance is difficult to adjust, the flow rate of the cleaning solvent flowing in the liquid source supply pipe cannot be controlled, and the liquid The raw material remaining in the raw material supply pipe cannot be cleaned effectively.

  The object of the present invention is to solve the above-mentioned problems of the prior art, reduce the amount of cleaning solvent used for cleaning the liquid source supply pipe, and increase the cleaning capability of the liquid source supply pipe Another object of the present invention is to provide a substrate processing apparatus and a method for manufacturing a semiconductor device.

The first invention includes a processing vessel for processing a substrate, a vaporizer for vaporizing a liquid raw material, a liquid raw material supply pipe for supplying the liquid raw material to the vaporizer, and a gas for vaporizing the liquid raw material in the processing vessel. A raw material gas supply pipe supplied into the liquid source supply pipe, at least one discharge pipe provided in the liquid raw material supply pipe for discharging a fluid in the liquid raw material supply pipe, and a conductance provided in the discharge pipe for adjusting a conductance of the discharge pipe. A substrate processing apparatus comprising: an adjustment mechanism; and a solvent supply mechanism that supplies a cleaning solvent into the liquid source supply pipe.
According to the present invention, since the conductance of the discharge pipe can be adjusted by the conductance adjustment mechanism, when cleaning the liquid raw material supply pipe using the cleaning solvent, by adjusting the conductance of the discharge pipe to be small, The amount of the cleaning solvent used can be reduced as compared with a conventional exhaust pipe that is discharged from a normal exhaust pipe in which conductance adjustment is difficult. Moreover, since the flow rate of the solvent for cleaning can be reduced by adjusting the conductance of the discharge pipe to be small, the liquid source supply pipe can be cleaned more effectively.

The second invention includes a step of carrying a substrate into a processing container, a step of supplying a liquid source from a liquid source supply pipe to a vaporizer and supplying the vaporized gas into the processing vessel to process the substrate, A step of unloading the processed substrate from the processing container; and supplying the cleaning solvent into the liquid source supply pipe while discharging from the discharge pipe provided in the liquid source supply pipe. And a step of stopping supply of the cleaning solvent into the liquid source supply pipe and discharging the cleaning solvent from the liquid source supply pipe through the discharge pipe. In the manufacturing method, the discharge pipe in the step of discharging the cleaning solvent from the liquid source supply pipe has a conductance of the discharge pipe in the step of cleaning the inside of the liquid source supply pipe A method of manufacturing a semiconductor device, characterized in that to be smaller than conductance.
According to the present invention, since the conductance of the discharge pipe can be adjusted by the conductance adjusting mechanism, when cleaning the liquid raw material supply pipe using the cleaning solvent, by adjusting the conductance of the discharge pipe to be small, The amount of the cleaning solvent used can be reduced as compared with a conventional exhaust pipe that is discharged from a normal exhaust pipe in which conductance adjustment is difficult. Moreover, since the flow rate of the solvent for cleaning can be reduced by adjusting the conductance of the discharge pipe to be small, the liquid source supply pipe can be cleaned more effectively.

According to a third invention, in the first invention, the discharge pipe has at least two discharge pipes, and the conductance adjusting mechanism is provided in any one of the at least two discharge pipes. Is a substrate processing apparatus.
In such an apparatus, a problem tends to occur particularly in the responsiveness of the conductance adjustment mechanism. However, according to the present invention, the conductance of the conductance adjustment mechanism provided in any one discharge pipe can be adjusted in advance. So you can solve these problems.

According to a fourth invention, in the third invention, further, the conductance adjusting mechanism is provided while supplying the cleaning solvent in the liquid raw material supply pipe, and the conductance is discharged from a discharge pipe having a smaller conductance than other discharge pipes. Then, the inside of the liquid source supply pipe is cleaned, and then the supply of the cleaning solvent into the liquid source supply pipe is stopped, and the conductance adjusting mechanism is not provided from the inside of the liquid source supply pipe And a controller for controlling the cleaning solvent to be discharged through the substrate processing apparatus.
When discharging the cleaning solvent through the discharge pipe provided with the conductance adjustment mechanism used when cleaning the liquid raw material supply pipe when discharging the cleaning solvent, the conductance of the discharge pipe is reduced, Although it becomes difficult to quickly discharge the cleaning solvent remaining in the liquid raw material supply pipe from the liquid raw material supply pipe, the cleaning solvent passes through another discharge pipe not provided with a conductance adjustment mechanism by the controller. If the control is performed to discharge the cleaning solvent, the cleaning solvent remaining in the liquid source supply pipe can be quickly discharged from the liquid source supply pipe.

  ADVANTAGE OF THE INVENTION According to this invention, the usage-amount of the solvent for washing | cleaning liquid raw material supply piping can be reduced, and also the washing | cleaning capability of liquid raw material supply piping can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a schematic configuration diagram of a control system for controlling the substrate processing apparatus for carrying out the semiconductor device manufacturing method.
The substrate processing apparatus to be controlled is configured with the processing apparatus 109 having the liquid supply apparatus 110 as a structural unit, and one or a plurality of these are controlled. Note that FIG. 2 shows only the configuration of the control unit, and the actual devices such as the processing device 109 and the liquid supply device 110 are configured to correspond to the respective control units. This is indicated by a broken line.

The processing apparatus 109 performs processing such as film formation on the substrate in the processing container. For example, the Ru or RuO ₂ film is formed by using the CVD method, more specifically, the MOCVD method. The liquid supply device 110 includes a raw material supply mechanism and a solvent supply mechanism which will be described later.

  The control system includes a central control unit 101, a processing device control unit 102, and a liquid supply device control unit 103.

  The central control unit 101 performs overall control of one or a plurality of processing devices 109. In the case where there are a plurality of processing apparatuses 109, it is also possible to supply a fluid such as a liquid raw material from one liquid supply apparatus 110 to the plurality of processing apparatuses 109.

  The processing apparatus control unit 102 controls various mechanisms such as a processing furnace, a substrate transfer machine, and a cassette elevator that constitute the processing apparatus 109. Further, the processing device control unit 102 controls the exhaust device so as to discharge while supplying the raw material gas supplied into the processing furnace at the time of substrate processing, and used for cleaning the raw material remaining in the liquid raw material supply pipe at the time of maintenance and cleaning. The exhaust system is controlled to discharge the cleaning solvent.

  The liquid supply device control unit 103 can also control the liquid supply device 110 and control the plurality of liquid supply devices 110 in an integrated manner. When a plurality of types of liquids are used in one processing apparatus 109, it is possible to increase the number of pipes in the liquid supply apparatus 110. The liquid supply device control unit 103 includes a temperature control unit 104, a pressure control unit 105, and a sequencer 106.

  The temperature control unit 104 is provided to control the inside of the pipe to an optimum temperature when supplying the liquid material and during maintenance of the liquid supply device 110. The pressure control unit 105 is provided to monitor the residual state of the liquid raw material and the cleaning solvent in the pipe during maintenance. The sequencer 106 opens and closes a valve provided in the pipe according to the order given from the liquid supply device control unit 103 during substrate processing or maintenance.

The liquid supply device control unit 103 operates various valves by the sequencer 106 to control supply of the liquid raw material into the liquid raw material supply pipe during substrate processing and supply of the cleaning solvent into the liquid raw material supply pipe during maintenance. . At that time, the liquid supply device control unit 103 controls the piping to a desired temperature based on the detection value of the temperature control unit 104 and controls the inside of the piping to a desired pressure based on the detection value of the pressure control unit 105. In addition, the liquid supply device control unit 103 has a determination function for performing the shortest maintenance based on the detection values of the temperature control unit 104 and the pressure control unit 105, and in order to minimize the maintenance time when replacing the raw material container. Also determine the optimal replacement period.
The liquid supply device control unit 103 constitutes a controller that controls the cleaning and the discharge of the cleaning solvent after the cleaning.

FIG. 1 is a schematic view showing a single-wafer CVD apparatus which is an example of a substrate processing apparatus 109 having a liquid supply apparatus 110 controlled by the control system described above.
The processing container 4 that processes the substrate 30 such as a silicon wafer includes a substrate support 42 that supports the substrate 30. A heater 43 for heating the substrate 30 is embedded in the substrate support 42.

A raw material gas supply pipe 17 for supplying a gas obtained by vaporizing the liquid raw material is connected to the processing container 4 via a valve 31 as a supply port for supplying a liquid raw material containing metal atoms. Further, an inert gas supply pipe 12 for supplying an inert gas such as N ₂ and an oxidizing gas supply pipe 16 for supplying an oxidizing gas are connected to the processing container 4. A remote plasma unit 45 is connected to the oxidizing gas supply pipe 16.

  An exhaust pipe 14 for exhausting the inside of the processing container 4 is connected to the processing container 4, and an exhaust device 5 a such as a vacuum pump is connected to the exhaust pipe 14. Each gas introduced into the processing container 4 reaches the downstream equipment such as an abatement device (not shown) through the exhaust pipe 14 and the exhaust device 5a. In addition, the piping in a figure is provided with the heating apparatus which is not shown in figure.

  A transfer chamber (not shown) is adjacent to the processing container 4 via a gate valve, and a cooling chamber and a load lock chamber are connected to the transfer chamber. The transfer chamber is provided with a substrate transfer machine. The substrate is introduced from the transfer chamber into the processing container 4 and subjected to processing such as film formation in the processing container 4 and then transferred to the cooling chamber through the transfer chamber. The

  The source gas supply pipe 17 is provided with a vent pipe 11 via a valve 32. An exhaust device 5 b is connected to the vent pipe 11. Further, the vaporizer 3 for vaporizing the liquid raw material is connected to the raw material gas supply pipe 17. A liquid raw material supply pipe 13 is connected to the vaporizer 3, and the liquid raw material supply pipe 13 is connected to the raw material container 1 via a valve 33, a liquid mass flow controller (MFC) 2, a valve 34, and a valve 35. .

A pressure gas supply pipe 15 a that supplies a pressure gas for extruding the liquid raw material in the raw material container 1 to the liquid material supply pipe 13 is connected to the raw material container 1 via a valve 36. A solvent supply pipe 18 is connected between the valve 34 and the valve 35 of the liquid source supply pipe 13. A solvent container 19 is connected to the solvent supply pipe 18 via a valve 37 and a valve 38. The solvent container 19 is connected via a valve 39 to a pressurized gas supply pipe 15 b for supplying a pressurized gas for pushing the cleaning solvent in the solvent container 19 to the solvent supply pipe 18.
The raw material container 1, the liquid raw material supply pipe 13, the pressure gas supply pipe 15a, the valve 34 to the valve 36, and the like constitute the raw material supply mechanism 28. The solvent supply mechanism 29 is configured by the solvent container 19, the solvent supply pipe 18, the pressure gas supply pipe 15b, the valves 37 to 39, and the like described above.

  In addition, a discharge pipe 26 for discharging the liquid in the liquid source supply pipe 13 is connected to the liquid source supply pipe 13. The discharge pipe 26 is connected to the vent pipe 11. The discharge pipe 26 includes an upstream discharge pipe 26 </ b> A provided on the upstream side of the liquid raw material supply pipe 13 and a downstream discharge pipe 26 </ b> B provided on the downstream side of the liquid raw material supply pipe 13.

  The upstream discharge pipe 26A includes a normal first discharge pipe 25a that is not provided with a conductance adjustment mechanism and a second discharge pipe 24a that is provided with a conductance adjustment mechanism, for example, a first needle valve 20a. Has two discharge pipes. The first discharge pipe 25a and the second discharge pipe 24a are provided in parallel. That is, the first discharge pipe 25a is connected to the vent pipe 11 through the valve 21a and the valve 22a from between the valve 34 and the valve 35 of the liquid source supply pipe 13. The second discharge pipe 24a is connected to the valve 22a of the first discharge pipe 25a from between the valve 21a and the valve 22a of the first discharge pipe 25a via the valve 23a and the first needle valve 20a. Connected downstream.

  The downstream discharge pipe 26B includes a normal first discharge pipe 25b that is not provided with a conductance adjustment mechanism, and a second discharge pipe 24b that is provided with a conductance adjustment mechanism, for example, a second needle valve 20b. Has two discharge pipes. The first discharge pipe 25b and the second discharge pipe 24b are provided in parallel. That is, the first discharge pipe 25b is connected to the vent pipe 11 through the valve 21b and the valve 22b from between the MFC 2 of the liquid source supply pipe 13 and the valve 33. The second discharge pipe 24b is connected between the valve 21b and the valve 22b of the first discharge pipe 25b and the valve 22b of the first discharge pipe 25b via the valve 23b and the second needle valve 20b. Connected downstream. The first needle valve 20a and the second needle valve 20b can adjust the flow rate of the fluid manually.

  Next, using the single-wafer CVD apparatus having the configuration as shown in FIG. 1 described above, a substrate process for forming a thin film on the substrate by MOCVD applying a cycle method as one step of a semiconductor device (device) manufacturing process; A procedure for performing maintenance for cleaning the liquid source supply pipe after the substrate processing will be described.

Here, an example in which a Ru or RuO ₂ film is formed as a thin film will be described. Examples of the liquid material include Ru (C ₂ H ₅ C ₅ H ₄ ) ₂ ; Ru (EtCp) ₂ , Ru [CH ₃ COCHCO (CH ₂ ) ₃ CH ₃ ] ₃ ; Ru (OD) ₃ diluted with CH ₃ COOC ₄ H ₉ (butyl acetate), Ru (EtCp) ₂ diluted with THF (tetrahydrofuran); C ₄ H ₈ O Those having a saturated vapor pressure higher than 10 Pa at room temperature (sufficiently higher than the ultimate pressure of the exhaust device used during maintenance) such as those diluted with alcohol or the like. The oxidizing gas used in the reforming step is a gas containing oxygen or a gas containing nitrogen, and for example, O ₂ , N ₂ O, NO, N ₂ , NH ₃ or the like is used. Further, nitrogen (N ₂ ) / argon (Ar) is used as an inert gas.

  As the cleaning solvent used in the cleaning step, a solvent that is highly volatile and does not remain is preferable. For example, a solvent that easily dissolves organic raw materials such as cyclohexane, normal hexane, ethylcyclohexane, and THF is used.

  Here, in all steps of the substrate processing and maintenance procedures (carrying-in process, processing process, carrying-out process, cleaning process, discharging process), the processing apparatus control unit 102 as a controller includes the vaporizer 3, the remote plasma unit 45, The start and stop of the exhaust devices 5a and 5b, the power supplied to the heater 43 embedded in the substrate support base 42, or the flow rate of the MFC 2 are controlled. In particular, in the treatment process, the cleaning process, and the discharge process, the liquid supply device control unit 103 includes valves 21a to 23a and 21b to 23b provided in the pipes according to the order given from the liquid supply device control unit 103 to the sequencer 106. And the opening and closing of the valves 31 to 39 is operated. The first and second needle valves 20a and 20b for adjusting the conductance provided in the second discharge pipes 24a and 24b previously reduce the conductance by narrowing the flow passage area.

(1) Carry-in process The substrate 30 is carried into the processing container 4 from the transfer chamber by the substrate transfer machine.

(2) Processing Step Next, the processing apparatus controller 102 (see FIG. 2) controls the heater 43 to raise the substrate temperature to the processing temperature and adjust the pressure in the processing container 4 to be the processing pressure. The valves 36, 35, 34, 33 and 31 are opened to supply the liquid raw material into the liquid raw material supply pipe 13. As a result, when pressurized gas such as N ₂ is supplied to the raw material container 1 in which the liquid raw material is stored, the liquid raw material is pushed into the liquid raw material supply pipe 13, and the flow rate of the pushed liquid raw material is controlled by the MFC 2. Then, it is vaporized by the vaporizer 3 and supplied as a raw material gas into the processing container 4 through the raw material gas supply pipe 17 to form a Ru or RuO ₂ film on the substrate 30 (film formation step). The oxidizing gas is activated via the remote plasma unit 45 and then supplied into the processing container 4 to modify the Ru or RuO ₂ film formed on the substrate 30 (modification step). The film forming step and the modifying step are alternately repeated a plurality of times by the processing apparatus control unit 102 to form a Ru or RuO ₂ film having a desired thickness.
Note that performing the film deposition step with the raw material gas supply, between the reforming step by oxidizing gas supply, purging with N ₂ the (N ₂ purge). That is, a procedure of film formation → N ₂ purge → reformation → N ₂ purge is set as one unit (one cycle), and this is repeated any number of times to obtain a desired film thickness.

  At the end of the processing step, the valves 36 and 35 and the valve 31 are closed to stop the supply of the liquid source into the liquid source supply pipe 13 and the valve 32 of the vent pipe 11 is opened. Fluid such as liquid raw material and raw material gas remaining in the liquid raw material supply pipe 13 and the raw material gas supply pipe 17 is discharged by the exhaust device 5 b through the vent pipe 11.

(3) Unloading process The substrate 30 on which the film forming process has been completed in the processing container 4 is unloaded to the cooling chamber through the transfer chamber.

(4) Cleaning Step When the substrate 30 is unloaded from the processing container 4 in the unloading step, the valve 33 is closed and the liquid source supply pipe 13 from which the remaining liquid source is discharged is shut off from the source gas supply pipe 17. After the liquid source supply pipe 13 is shut off from the source gas supply pipe 17, the valves 39, 38, 37, 21 a, 23 a, 21 b, and 23 b are opened in order to supply the cleaning solvent into the liquid source supply pipe 13. As a result, when a pressurized gas such as N ₂ is supplied to the solvent container 19, the cleaning solvent is pushed into the solvent supply pipe 18, and the pushed cleaning solvent is supplied into the liquid source supply pipe 13.

  The cleaning solvent supplied into the liquid raw material supply pipe 13 includes an upstream discharge pipe 26A provided on the upstream side of the liquid raw material supply pipe 13 and a downstream discharge pipe provided on the downstream side of the liquid raw material supply pipe 13. It branches into 26B, flows into the vent pipe 11, and is discharged via the exhaust device 5b. Thereby, the inside of the liquid raw material supply pipe 13 is cleaned.

  The cleaning solvent branched to the upstream discharge pipe 26A is discharged from the first discharge pipe 25a to the vent pipe 11 through the second discharge pipe 24a, and the cleaning solvent discharged to the vent pipe 11 is the exhaust device 5b. It is discharged by. The cleaning solvent branched to the downstream discharge pipe 26B passes through the MFC 2 and is discharged from the first discharge pipe 25b to the vent pipe 11 through the second discharge pipe 24b and is discharged to the vent pipe 11. The working solvent is discharged by the exhaust device 5b.

At this time, the needle valves 20a and 20b for adjusting the conductance provided in the second discharge pipes 24a and 24b through which the cleaning solvent passes are adjusted in advance so that the conductance is reduced by narrowing the channel area. As a result, the amount of the solvent used for cleaning that passes through the second discharge pipes 24a and 24b can be suppressed, so that the amount of solvent used can be reduced as compared with the case of discharging from a normal discharge pipe that is difficult to adjust the conductance as in the prior art. . In order to reduce the amount of solvent used, the total of the amount of cleaning solvent used that is branched into two discharge pipes, the upstream discharge pipe 26A and the downstream discharge pipe 26B, is adjusted by adjusting the conductance. It is less than the amount of solvent used when discharging from one difficult normal discharge pipe.
In addition, since the conductance of the needle valves 20a and 20b is adjusted to be small, the flow rate of the cleaning solvent flowing in the liquid source supply pipe 13 is slowed down, so that the liquid source remaining in the liquid source supply pipe 13 is cleaned. Can be done more effectively.

  In addition, the cleaning solvent supplied into the liquid source supply pipe 13 is divided into an upstream discharge pipe 26 A provided on the upstream side of the liquid source supply pipe 13 and a downstream side provided on the downstream side of the liquid source supply pipe 13. Since the liquid is branched and discharged to the discharge pipe 26B, the liquid raw material supply pipe 13 is compared with the case where the liquid raw material supply pipe 13 is discharged from one discharge pipe provided only on the upstream side of the liquid raw material supply pipe 13. The remaining liquid raw material can be more effectively cleaned.

  The needle valves 20a and 20b are not limited to the manual type, and may be automatically controlled or automatically variable like a mass flow controller, but it is considered that precise control is often unnecessary. Therefore, a manual type is sufficient.

(5) Discharge process Next, the supply of the cleaning solvent into the liquid raw material supply pipe 13 is stopped. At the same time, the flow path area provided in parallel with the flow paths of the upstream discharge pipe 26A and the downstream discharge pipe 26B from the second discharge pipes 24a and 24b in which the flow path area is reduced to reduce the conductance. Is switched to the first discharge pipes 25a and 25b having a large conductance and the cleaning solvent is discharged from the first discharge pipes 25a and 25b.

  In order to promote the discharge of the cleaning solvent, the first discharge pipes 25a and 25b and the vent pipe 11 may be heated by a pipe heater (not shown) at the time of discharge. The heating temperature at this time may be about 20 to 100 ° C or about 20 to 30 ° C. The higher the temperature, the higher the vapor pressure, so the cleaning solution tends to be discharged, but after cleaning it is necessary to refill the liquid raw material to return to a steady state, so the temperature is necessary for the entire device and for cleaning. Set appropriately according to the overall time.

Further, in order to promote the discharge of the cleaning solvent, the inside of the liquid source supply pipe 13 may be purged with an inert gas such as nitrogen N ₂ . The purge is preferably a cycle purge in which the following two steps are alternately repeated in order to dilute the vaporized cleaning solvent.
(1) Purge by flowing an inert gas through the second discharge pipes 24a and 24b having a small flow path area.
(2) The supply of the inert gas is stopped, and the residual gas is discharged via the first discharge pipes 25a and 25b having a wide flow path.
The reason for this cycle purge is that the cleaning solvent may be reliquefied depending on the temperature, so it is more effective to expedite the vaporization of the cleaning solvent sooner. is there.

When cleaning of the liquid raw material supply pipe is completed including the discharge of the cleaning solvent, maintenance such as replacement of the raw material container 1 and replacement of the raw material supply line pipe and parts is performed as necessary. After replacing the piping and parts, confirm the vacuum sealing of the raw material supply line (leak check), and then replace the atmosphere with inert gas such as nitrogen N ₂ to reduce the pressure. If the liquid raw material being used is hydrolyzable, it is necessary to reduce the residual moisture in the piping, but otherwise it may cause quality degradation. In order to remove moisture in the atmosphere adsorbed on the open part, the vapor pressure is increased while heating, and replacement with an inert gas or solvent washing is sufficiently performed. Wash the open part of the raw material supply line with the washing solvent. The cleaning method may be the same as the cleaning method of the liquid material supply pipe in which the liquid material remains.

  After the pipe cleaning is completed in this way, the pressure is reduced and the raw material supply line is sequentially filled with the liquid raw material from the raw material container 1 side. Up to this point, the maintenance of the raw material supply line is completed. It should be noted that a series of cleaning operations is more efficient when performed automatically, but may be performed manually.

  As described above, according to the present embodiment, when supplying the cleaning solvent to the liquid source supply pipe 13 and cleaning the inside of the liquid source supply pipe 13, the liquid source supply unit 103 controls the liquid source supply. While supplying the cleaning solvent into the pipe 13, needle valves 20a and 20b are provided and discharged from the second discharge pipes 24a and 24b whose conductance is smaller than that of the first discharge pipes 25a and 25b. Since the inside of 13 is cleaned, the amount of the cleaning solvent used can be reduced as compared with the conventional case of discharging from the normal discharge pipe. Moreover, since the flow rate of the solvent can be controlled slowly, the raw material remaining in the liquid raw material supply pipe 13 can be more effectively cleaned.

  Further, when the cleaning solvent is discharged, the cleaning solvent is passed through the second discharge pipes 24a and 24b provided with the first and second needle valves 20a and 20b used when the liquid source supply pipe 13 is cleaned. Since the conductance of the second discharge pipes 24a and 24b is reduced, the cleaning solvent remaining in the liquid raw material supply pipe 13 can be quickly discharged from the liquid raw material supply pipe 13. Although difficult, according to the present embodiment, when the supply of the cleaning solvent to the liquid source supply pipe 13 is stopped and the cleaning solvent is discharged from the liquid source supply pipe 13, the liquid supply device control unit 103, the cleaning solvent is discharged through the first discharge pipes 25a and 25b having a large conductance in which the first and second needle valves 20a and 20b are not provided. Since it is, and the washing solvent remaining in the liquid raw material supply pipe 13 can be quickly discharged from the liquid material supply pipe within 13.

  Therefore, the maintenance for cleaning the liquid source supply pipe 13 can be optimized and shortened.

  Further, since the discharge pipe 26 is provided not only on the upstream side of the raw material container 1 but also between the MFC 2 and the vaporizer 3 on the downstream side, the liquid raw material supply pipe 13 can be cleaned more quickly. It becomes like this. In this case, it is preferable to increase the number of discharge pipes within a range in which the amount of solvent used can be reduced rather than discharging from conventional normal pipes.

  Further, when a conductance adjusting mechanism is provided in the discharge pipe for discharging the fluid in the liquid source supply pipe 13, when cleaning the liquid source supply pipe 13, the conductance of the discharge pipe is reduced, and the liquid source supply pipe 13 In order to increase the conductance when discharging the cleaning solvent, the conductance adjustment mechanism cannot be adjusted in advance if there is only one discharge pipe, so the responsiveness of the conductance adjustment mechanism tends to be a problem. According to the present embodiment, the upstream discharge pipe 26A has two discharge pipes 24a and 25a, and the needle valve 20a is provided in any one of the two discharge pipes 24a and 25a. . The downstream discharge pipe 26B also has two discharge pipes 24b and 25b, and the needle valve 20b is provided in any one of the two discharge pipes 24b and 25b. Therefore, the conductance of the needle valves 20a and 20b can be adjusted in advance, so that the above-described problem of responsiveness can be solved.

In the above embodiment, the case where the Ru or RuO ₂ film is formed has been described. However, the present invention may be applied to the case where, for example, a Ta ₂ O ₅ film, an HfO ₂ film, or an HfSiO film is formed. .
Moreover, the washing | cleaning solvent should just be a solvent which can melt | dissolve the raw material which is a solute. For example, when a Ta ₂ O ₅ film is formed using PETa (Ta (OC ₂ H ₅ ) ₅ : pentoethoxytantalum) as a liquid raw material, an alcohol such as ethanol may be used as a cleaning solvent. In the case where a Ru or RuO ₂ film is formed using Ru (EtCp) ₂ , Ru (OD) ₃ or the like as a liquid source as in the present embodiment, THF or the like is preferably used as a cleaning solvent. Further, for example, when forming an HfO ₂ film using Hf-MMP as a liquid source, or forming an HfSiO film using Hf-MMP and Si-MMP as a liquid source, CH ₃ (CH ₂ ) ₄ CH ₃ (hexane), C ₂ H ₅ C ₆ H ₁₁ (ethylcyclohexane), C ₈ H ₁₈ (octane) or the like may be used. Thus, there are a wide variety of types and combinations of cleaning solvents for liquid raw materials.

It is the schematic which shows an example of the single wafer type CVD apparatus in embodiment. It is a block diagram of the control system of the substrate processing apparatus in an embodiment. It is the schematic which shows the single wafer type CVD apparatus of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid raw material container 3 Vaporizer 4 Processing container 11 Vent piping 13 Liquid raw material supply piping 17 Raw material gas supply piping 19 Solvent container 20a, 20b Needle valve (conductance adjustment mechanism)
24a First discharge pipe 24b First discharge pipe 25a Second discharge pipe 25b Second discharge pipe 26 Discharge pipe 26A Upstream discharge pipe 26B Downstream discharge pipe 28 Raw material supply mechanism 29 Solvent supply mechanism 30 Substrate

Claims (2)

A processing vessel for processing a substrate;
A vaporizer for vaporizing the liquid raw material;
Liquid raw material supply piping for supplying the liquid raw material to the vaporizer;
A source gas supply pipe for supplying a gas obtained by vaporizing the liquid source into the processing container;
At least one discharge pipe provided in the liquid source supply pipe for discharging the fluid in the liquid source supply pipe;
A conductance adjustment mechanism for adjusting the conductance of the discharge pipe provided in the discharge pipe;
A solvent supply mechanism for supplying a cleaning solvent into the liquid source supply pipe;
A substrate processing apparatus comprising: Carrying a substrate into a processing container;
Supplying a liquid source to a vaporizer from a liquid source supply pipe and supplying the vaporized gas into the processing container to process the substrate;
A step of unloading the processed substrate from the processing container;
A step of cleaning the liquid source supply pipe by discharging from a discharge pipe provided in the liquid source supply pipe while supplying a cleaning solvent into the liquid source supply pipe;
Stopping the supply of the cleaning solvent into the liquid source supply pipe and discharging the cleaning solvent from the liquid source supply pipe through the discharge pipe;
In the manufacturing method of the semiconductor device having
The conductance of the discharge pipe in the step of cleaning the liquid source supply pipe is made smaller than the conductance of the discharge pipe in the step of discharging the cleaning solvent from the liquid source supply pipe. A method of manufacturing a semiconductor device.

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