JP2009302353A - Semiconductor manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform film deposition processing of high quality by removing microparticles of submicron size. <P>SOLUTION: The microparticles produced from a reaction by-product deposited film 20 in a reaction furnace are forcibly removed and discharged before the film deposition processing by removing particles with a purge gas to which an elastic wave 21 is applied, so production of the microparticles is suppressed in the film deposition processing and the film deposition processing of high quality is carried out. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor manufacturing apparatus for manufacturing a semiconductor element by a CVD process.

  In the process of manufacturing a semiconductor element, a film-forming process is performed on a substrate to be processed such as a wafer by chemical vapor deposition (CVD) (Chemical Vapor Deposition).

Hereinafter, a conventional semiconductor manufacturing apparatus will be described with reference to FIG.
FIG. 6 is a schematic diagram showing the configuration of a conventional semiconductor manufacturing apparatus.
First, a conventional semiconductor manufacturing apparatus that performs CVD film formation while reducing particles will be described with reference to FIG.

  The semiconductor manufacturing apparatus shown in FIG. 6 is a batch processing type semiconductor manufacturing apparatus, in particular, a load lock type semiconductor manufacturing apparatus including a load lock chamber 101 as a spare chamber. A reactor 102 is connected to the upper surface of the airtight load lock chamber 101 in an airtight manner, and a substrate transfer chamber (not shown) is connected to the load lock chamber 101 through a gate valve (not shown) in an airtight manner. Yes. The reactor 102 is provided with a furnace port flange 104 hermetically attached to the upper surface of the load lock chamber 101, an outer tube 105 installed upright in the furnace port flange 104, and concentrically installed in the outer tube 105. The inner tube 106, a heater (not shown) provided so as to surround the outer tube 105, and the like. Further, gas introduction lines 107 and 108 for introducing a reaction gas communicate with the inside of the reaction furnace 102 and an exhaust device 109 communicates with the inside of the reaction furnace 102. The load lock chamber 101 is provided with a boat elevator (not shown), and the boat 110 is moved up and down, and the boat 110 is loaded and withdrawn into the reaction furnace 102. Wafers 111, which are substrates to be processed, are loaded into the boat 110 in a horizontal posture in multiple stages. A gas purge nozzle 112 is provided upright in the load lock chamber 101 so as to be parallel to the boat 110 in the lowered state, and a vacuum exhaust device 113 is communicated with the load lock chamber 101. The inside of the load lock chamber 101 is evacuated by 113, and further, nitrogen gas, which is one of inert gases, is supplied by the gas purge nozzle 112 to return to atmospheric pressure.

Hereinafter, wafer processing will be described.
The boat 110 is lowered (unloaded) when the load lock chamber 101 and the reaction furnace 102 are at atmospheric pressure, and a predetermined number of wafers 111 are loaded into the boat 110 by a substrate transfer machine (not shown) while the boat 110 is lowered. Is done. The inside of the reaction furnace 102 is maintained at a film forming temperature during operation, the boat 110 is raised by a boat elevator (not shown), and the wafer 111 is loaded into the reaction furnace 102. The inside of the reaction furnace 102 is evacuated by the exhaust device 109, a reaction gas is introduced from the gas introduction lines 107 and 108, and a film forming process is performed on the wafer 111. After the film forming process is completed, the inside of the reaction furnace 102 is returned to the atmospheric pressure, and the boat 110 is unloaded by a boat elevator (not shown) and pulled out into the load lock chamber 101. The boat 110 is cooled in the load lock chamber 101, and the wafer 111 is discharged by a substrate transfer machine (not shown). When the unloading is completed, unprocessed wafers are further loaded into the boat 110, and then the load lock chamber 101 is once evacuated by the evacuation device 113 to remove moisture and oxygen in the air. Thereafter, nitrogen gas is introduced from the gas purge nozzle 112, the load lock chamber 101 is returned to atmospheric pressure, and is made substantially the same pressure as the reaction furnace 102. Next, the boat is loaded into the reaction furnace 102, and the processing is continued (see, for example, Patent Document 1).

  A conventional semiconductor manufacturing apparatus is a semiconductor element manufacturing method in which a gas is purged by lowering the temperature in the reaction furnace to a temperature lower than the film forming temperature in a state where the substrate is unloaded from the inside of the reaction furnace for forming a film on the substrate to be processed. In addition, the temperature drop and the gas purging step relate to a method of manufacturing a semiconductor device performed after unloading a processed substrate from the reaction furnace and before loading a substrate to be processed next. The descent is related to a method of manufacturing a semiconductor device in which the temperature drop caused when the substrate to be processed is loaded into the reaction furnace, and after the temperature drop, the substrate to be processed next is loaded into the reaction furnace. In the meantime, the present invention relates to a method of manufacturing a semiconductor device having a step of raising the temperature in the reaction furnace, and the temperature in the reaction furnace at the time of the temperature rise loads the substrate to be processed next into the reaction furnace. Temperature in the reactor The present invention relates to a method for manufacturing a semiconductor device that is equal to or higher than the temperature at the time of the temperature drop. In addition, the boat is unloaded from the reaction furnace after batch processing in the reaction furnace with a plurality of substrates to be processed loaded in the boat. The processed substrate is taken out of the boat, and the unprocessed substrate to be processed next is loaded into the boat and loaded again into the reactor. The present invention relates to a method of manufacturing a semiconductor device, and in the process of unloading a boat from a reactor to a preliminary chamber, cooling a processed substrate on the boat in the preliminary chamber, and removing the processed substrate from the boat. In the process of lowering the temperature in the reactor and evacuating and purging the gas, and then loading the unprocessed substrate to be processed next in the spare chamber into the boat, the temperature in the reactor is increased and the reactor is The present invention relates to a method for manufacturing a semiconductor device in which the pressure is substantially the same as that of a preliminary chamber, and relates to a method for manufacturing a semiconductor device in a nitride film forming process in which the film thickness during film formation is 1000 mm or more. The gas purging method relates to a method for manufacturing a semiconductor device in which evacuation is performed while introducing a small amount of an inert gas into a reaction furnace.

  A reaction furnace for performing a film forming process on the substrate to be processed, a reaction gas introduction / exhaust means, an inert gas introduction means for purging the inside of the reaction furnace, and a temperature control means for controlling the temperature in the reaction furnace; After the substrate to be processed is processed in the reaction furnace, the inside of the reaction furnace is unloaded from the reaction furnace, and the temperature in the reaction furnace is lowered so that the temperature is lower than the film formation temperature. The present invention relates to a semiconductor manufacturing apparatus configured as described above, and also relates to a semiconductor manufacturing apparatus in which the temperature in the reaction furnace is increased before the substrate to be processed next is loaded into the reaction furnace after the temperature is lowered. It is.

In addition, with no substrate to be processed in the reaction furnace, the temperature in the reaction furnace is lowered, the stress of the reaction by-product deposited film adhering to the reaction furnace is increased, and cracks are forcibly generated in the deposited film. The present invention relates to a semiconductor manufacturing apparatus that forcibly discharges fine particles generated when cracks occur by gas purge.
JP 2003-306904 A

  When a CVD process is performed on a wafer, for example, a SiN film is generated, a reaction by-product is deposited on the reaction chamber wall surface to form a film. The deposited film grows every time the substrate processing is repeated. When the thickness exceeds a predetermined thickness, a crack is generated, peeled off, becomes particles, floats in the reaction chamber, and adheres to the substrate to be processed.

  If the number of particles increases and the number of particles adhering to the substrate to be processed increases, the yield decreases and the product quality also decreases. Further, cleaning with a cleaning gas is a problem because of the reason that the influence of deterioration on the quartz member becomes very large.

Furthermore, with the miniaturization, removal of fine particles of submicron size, which has not been a problem until several years ago, has become a problem.
It has been difficult to remove fine particles generated in a deposited film that has been forcedly cracked due to a conventional vacuum break or a temperature drop by simply ejecting a purge gas.

  In order to solve the above-described problems, an object of the semiconductor manufacturing apparatus of the present invention is to remove fine particles of submicron size and perform a high quality film forming process.

  In order to achieve the above object, a semiconductor manufacturing apparatus of the present invention performs a CVD film formation process on a substrate to be processed using a reaction gas, a reaction furnace for performing the film formation process on the substrate to be processed, and the reaction A board for holding the substrate to be processed in a furnace, a reaction gas introduction line for introducing the reaction gas into the reaction furnace, a purge gas introduction line for introducing purge gas into the reaction furnace, and a gas in the reaction furnace An exhaust pipe, a heater for controlling the temperature in the reaction furnace, and an elastic wave application device for applying an elastic wave to the purge gas, and the inner wall of the reaction furnace by the purge gas to which the elastic wave is applied Particles deposited on the surface and the board surface are removed.

Further, the elastic wave applying device is a Karman vortex generator for generating Karman vortices.
Further, one or a plurality of the elastic wave applying devices are provided inside the reaction furnace.

Further, the elastic wave applying device is provided in the vicinity of the inner wall of the reaction furnace and in the vicinity of the board.
Further, the elastic wave applying device is provided outside the reaction furnace of the purge gas introduction line.

Further, in order to change the frequency of the elastic wave applied to the purge gas, a mechanical function for changing the flow rate and flow path of the purge gas is provided.
The exhaust pipe may further include a mechanical adjustment function for adjusting the pressure of the gas exhausted from the exhaust pipe.

  As described above, fine particles of submicron size can be removed, and high-quality film formation processing can be performed.

  As described above, according to the present invention, fine particles generated from the reaction by-product deposited film in the reaction furnace are forcibly removed and discharged before the film forming process by removing the particles with the purge gas to which the elastic wave is applied. Therefore, the generation of fine particles can be suppressed during the film forming process, and a high quality film forming process can be performed.

A semiconductor manufacturing apparatus using a low pressure CVD apparatus according to the first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic diagram showing the configuration of a semiconductor manufacturing apparatus using a low pressure CVD apparatus according to the first embodiment. FIG. 3 is a diagram showing a state in which elastic waves are generated from a Karman vortex generator, FIG. 4 is a diagram for explaining a state in which deposits attached to the reactor are removed by elastic waves, and FIG. 5 is a semiconductor of the present invention. It is a flowchart which shows the process process in a manufacturing apparatus.

  In FIG. 1, 1 is a vacuum exhaust pipe, 2 is a reaction gas introduction line, and 3 is a purge gas introduction line. Reference numeral 4 denotes a quartz board on which a substrate to be processed is placed. Reference numeral 5 denotes a reactor. Reference numeral 6 denotes a portion for generating an elastic wave, which is the Karman vortex generator of the present invention. Reference numeral 7 denotes a board turntable. Reference numeral 8 denotes an exhaust opening / closing valve. Reference numeral 9 denotes a suction valve. Reference numeral 10 denotes a gas introduction pipe. Reference numeral 50 denotes a heater.

The vacuum exhaust pipe 1 is connected to the reaction furnace 5 via an intermediate exhaust opening / closing valve 8, and the reaction gas introduction line 2 and the purge gas introduction line 3 are connected via an intermediate intake valve 9.
Inside the reaction furnace 5, a gas introduction pipe 10 connected from the suction valve 9 extends to the upper part inside the reaction furnace 5. A plurality of Karman vortex generators 6 are connected from the middle of the gas introduction pipe 10.

The reaction furnace 5 is hermetically sealed with the board rotating disk 7, the quartz board 4 on which the substrate to be processed is placed, and the heater 50 for heating the reaction furnace 5 is installed outside.
The operation of the semiconductor manufacturing apparatus using the low pressure CVD apparatus configured as described above will be described below with reference to FIGS.

  First, in general, in order to form a film on a substrate to be processed with a low pressure CVD apparatus, the reaction furnace 5 and the board turntable 7 are opened, and the quartz board 4 on which the substrate to be processed is loaded is loaded into the reaction furnace 5 (step). 1).

  Thereafter, the inside of the reaction furnace 5 is evacuated from the vacuum exhaust pipe 1, and the reaction gas is introduced from the reaction gas introduction line 2 at a low speed (step 2). In the low pressure CVD apparatus, the reaction gas pressure in the reaction furnace 5 is controlled, and the temperature in the reaction furnace 5 is controlled by the heater 50 to perform the film forming process on the substrate to be processed (step 3). After the film forming process is completed, an inert gas is gradually introduced into the reaction furnace 5 from the purge gas introduction line 3, while the reaction gas is exhausted from the vacuum exhaust pipe 1 (step 4). In this operation, the quartz board 4 is cooled at the same time. After the cooling, the quartz board 4 is taken out from the reaction furnace 5 and the substrate to be processed is taken out from the quartz board 4 by a transfer machine or the like. Further, a new unprocessed substrate is inserted into the quartz board 4, and the film forming process of the description operation is continuously repeated.

  Although the film forming process is repeatedly performed on the substrate to be processed by the above-described operation, when the film forming process is performed several times, the deposited film 20 is formed on the inner wall of the quartz board 4 or the reaction furnace 5 as shown in FIG. Will stick. Finally, the deposited film 20 peels off during the film forming process of the substrate to be processed and falls off.

  In order to prevent the deposition film 20 from peeling off or falling off, the exhaust opening / closing valve 8 is opened and deactivated in a state where there is no substrate to be processed in the reaction furnace 5 after the substrate is processed several times. The gas is allowed to flow at high speed from the purge gas introduction line 3 to the Karman vortex generator 6 through the gas introduction line 10 (step 5).

  When an inert gas flows into the Karman vortex generator 6 at a high speed, Karman vortices 14 are generated and elastic waves 21 are generated. The quartz board 4 and the deposited film 20 that is about to peel off from the inner wall of the reaction furnace 5 are forcibly peeled off by the inert gas to which the elastic wave 21 is applied, and are discharged from the vacuum exhaust pipe 1 (step 6).

  In addition, the purge gas introduction line 3 is closed, the exhaust on-off valve 8 is opened, the degree of vacuum in the reaction furnace 5 is increased, a vacuum break is instantaneously generated, and the stress of the deposited film adhering to the reaction furnace 5 is increased. To forcibly generate cracks in the deposited film. At the same time, an inert gas is allowed to flow through the Karman vortex generator 6 and an elastic wave 21 is applied to the inert gas, thereby facilitating breakage from the cracked portion of the deposited film. The deposited film 20 which is about to be peeled off can be forcibly peeled off and discharged from the vacuum exhaust pipe 1. Further, by repeating this series of operations several times, fine particles can be removed more effectively.

In addition, a plurality of Karman vortex generators 6 may be installed in the reaction furnace 5, and it is desirable that the ejection pipe 13 that hits the tip of the Karman vortex generator 6 is in the vicinity of the reaction furnace 5 and in the vicinity of the quartz board 4.
Hereinafter, a method of applying an elastic wave to the purge gas of this embodiment will be described with reference to FIG. FIG. 3 shows how the elastic wave 21 is generated by the Karman vortex 14 in the semiconductor manufacturing apparatus using the low-pressure CVD apparatus of the present invention. A plurality of Karman vortex generators 6 as shown in FIG. 3 are connected to the gas introduction pipe 10. Reference numeral 10 denotes a gas introduction pipe, which is connected to each Karman vortex generator 6. In each Karman vortex generator 6, a vibrating object 11 is located at the center of the ejection pipe 13.

  When performing the gas purge operation, the gas 12 flows from the gas introduction pipe 10 to each Karman vortex generator 6. In the Karman vortex generator 6, the oscillating object 11, which is a stationary object, is in the flowing gas, so that a periodic vortex (Karman vortex 14) is generated in the subsequent flow.

Each of the Karman vortices 14 generates an elastic wave 21. The frequency f at this time is equal to the number of Karman vortices 14 emitted from the vibrating object 11 and is expressed by the following equation.
f = St · V / d Equation 1
St is the Strahull number and varies depending on the shape of the vibrating object 11. In the case of a cone, St = 0.255.

V is an air velocity m / s, and d is a representative dimension of the vibrating object 11.
In actual calculation, when the vibrating object 11 is a cone, the diameter d = 1.5 mm, the diameter Φ of the tube through which the gas flows Φ = 6.37 mm, and the flow rate V = 26.1 m / s when the flow rate is 50 slm. f is 4.44 kHz.

Since the frequency f changes in proportion to the air velocity from Equation 1, it can be adjusted to the desired frequency f by controlling the flow diameter, flow rate, and pressure with each adjusting valve.
The flow diameter can be realized by providing a mechanical restriction in the ejection pipe 13, and the flow rate and pressure can be realized by providing a mechanical adjustment function in the exhaust pipe opening / closing valve 8 and the suction valve 9. Since the frequency f of the elastic wave 21 applied to the gas can be adjusted, as shown in FIG. 4, the adhesion force of the deposited film 20 adhering to the inner wall of the reaction furnace 7 becomes weak, and the deposited film 20 When the elastic wave 21 is irradiated at a place where the film is peeled off and is likely to fall off, it can be easily and forcibly removed depending on the size of the dropping off part.

  In the case of the first embodiment having the configuration of FIG. 1, when the substrate to be processed is placed on the quartz board 4 and processed, the reaction gas also passes through a plurality of Karman vortex generators 6, so that Karman vortices are generated. In the case of the above calculation example, when the vibrating object 11 is a cone, the diameter d = 1.5 mm, the diameter Φ = 6.37 mm of the tube through which the gas flows, and the flow rate is 0.1-1 slm, the flow velocity V = 5. The frequency f generated at 2 to 52 cm / s is 8.8 to 88 Hz, which is a level that is not affected by applying the Karman vortex to the reaction gas. Further, since a plurality of Karman vortex generators 6 are used, a flow rate necessary for filling the reactor 5 can be secured.

  On the other hand, when the purge gas is sucked, since the frequency f for removing particles must be as high as several KHz, the flow velocity must be as high as V = several tens m / s from the above calculation. In this case, in order to ensure the flow rate of one Karman vortex generator 6, one or several of the Karman vortex generators 6 are opened, and the remaining many are temporarily closed and purged. Good. For example, the Karman vortex generator 6 located in the upper part of the reaction furnace 5 may be opened at the beginning of the purge, and the part opened to the lower part of the reaction furnace 5 may move over time. By repeating this operation, the elastic wave generated by the Karman vortex generator 6 in the reaction furnace 5 can be uniformly applied to the reaction furnace 5, so that the particle exclusion process can be made uniform.

  As described above, according to this embodiment, the reactive gas introducing means, the purge gas introducing means for purging, the means for exhausting the gas, and the means for applying the elastic wave to the purge gas are provided, so that the purge gas to which the elastic wave is applied is provided. By removing particles, the fine particles generated from the deposited film in the reaction furnace are forcibly removed and discharged before the film formation process, so that the generation of fine particles can be suppressed during the film formation process, resulting in high quality film formation. Processing can be performed. In addition, since the reactor must be cleaned before the deposited film is completely peeled off, the cleaning time interval becomes longer, the maintainability is improved, the operating rate is improved, and the processing time is also longer than before. Exhibits excellent effects such as never.

A second embodiment of the present invention will be described below with reference to FIG.
FIG. 2 is a schematic diagram showing the configuration of a semiconductor manufacturing apparatus using a low pressure CVD apparatus according to the second embodiment.

The semiconductor manufacturing apparatus according to the second embodiment shown in FIG. 2 differs from the first embodiment in the following points.
A plurality of Kalman generators 6 connected to the gas introduction line 10 in the reaction furnace 5 provided in the first embodiment are not installed, but a plurality of open ports 30 exist instead. On the other hand, there is a Karman vortex generator 6 in the middle of the purge gas introduction line 3 and the suction valve 9, and an elastic wave is applied to the purge gas at this portion. The configuration of the other parts is the same as that of the first embodiment. The operation is also the same as in the first embodiment.

  The elastic wave generation process by the Kalman generator 6 is the same as that of the first embodiment. In the first embodiment, an elastic wave is generated by the Kalman generator 6 when introduced into the reaction furnace 5, but in the second embodiment, the Kalman generator 6 provided in the purge gas introduction line 3 is used. An elastic wave is generated, and the elastic wave is introduced into the reaction furnace 5 through the gas introduction line 10.

  As described above, also in this embodiment, by removing particles with the purge gas to which the elastic wave is applied, the fine particles generated from the deposited film in the reaction furnace are forcibly removed and discharged before the film forming process. Generation of fine particles can be suppressed during the film forming process, and a high quality film forming process can be performed.

  In each of the embodiments described above, the method of generating Karman vortices using a Kalman generator has been described as an example of a method for generating elastic waves. However, Karman vortices may be generated by methods other than those described above. Elastic waves may be generated by methods other than vortices.

  INDUSTRIAL APPLICABILITY The present invention is useful for a semiconductor manufacturing apparatus or the like that can remove fine particles of submicron size and perform a high quality film forming process and manufacture a semiconductor element by a CVD process.

Schematic showing the configuration of a semiconductor manufacturing apparatus using a low pressure CVD apparatus according to the first embodiment Schematic which shows the structure of the semiconductor manufacturing apparatus by the low pressure CVD apparatus which concerns on a 2nd Example. Diagram showing how an elastic wave is generated from a Karman vortex generator Diagram for explaining how deposits attached to the reactor are removed by elastic waves The flowchart which shows the processing process in the semiconductor manufacturing apparatus of this invention Schematic diagram showing the configuration of a conventional semiconductor manufacturing equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum exhaust pipe 2 Reaction gas introduction line 3 Purge gas introduction line 4 Quartz board 5 Reactor 6 Karman vortex generator 7 Board rotation board 8 Discarding on-off valve 9 Suction valve 10 Gas introduction pipe 11 Oscillator 12 Gas 13 Jet pipe 14 Karman vortex 20 Deposit 21 Elastic wave 30 Opening port 50 Heater 101 Load lock chamber 102 Reactor 104 Furnace port flange 105 Outer tube 106 Inner tube 107 Gas introduction line 108 Gas introduction line 109 Exhaust device 110 Boat 111 Wafer 112 Gas purge nozzle 113 Vacuum exhaust apparatus

Claims (7)

Perform the CVD film formation process on the substrate to be processed using the reaction gas,
A reactor for performing a film forming process on the substrate to be processed;
A board for holding the substrate to be processed in the reaction furnace;
A reaction gas introduction line for introducing the reaction gas into the reaction furnace;
A purge gas introduction line for introducing purge gas into the reaction furnace;
An exhaust pipe for exhausting the gas in the reactor;
A heater for controlling the temperature in the reactor;
An apparatus for applying an elastic wave to the purge gas, and removing particles deposited on the inner wall surface of the reactor and the board surface by the purge gas to which the elastic wave is applied. .   2. The semiconductor manufacturing apparatus according to claim 1, wherein the elastic wave applying device is a Karman vortex generator for generating Karman vortices.   3. The semiconductor manufacturing apparatus according to claim 1, wherein one or a plurality of the elastic wave applying devices are provided inside the reaction furnace. 4.   4. The semiconductor manufacturing apparatus according to claim 3, wherein the elastic wave applying device is provided in the vicinity of an inner wall of the reaction furnace and in the vicinity of the board.   The semiconductor manufacturing apparatus according to claim 1, wherein the elastic wave applying device is provided outside the reaction furnace of the purge gas introduction line.   3. The semiconductor manufacturing apparatus according to claim 2, further comprising a mechanical function of changing a flow rate and a flow path of the purge gas in order to change a frequency of the elastic wave applied to the purge gas.   The semiconductor manufacturing apparatus according to claim 2, further comprising a mechanical adjustment function for adjusting a pressure of the gas exhausted by the exhaust pipe.

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