JP2008004663A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve yield in manufacture of a semiconductor device which uses a decompression treatment device equipped with an atmospheric pressure sensor. <P>SOLUTION: A boat 13 is inserted in a tube 12 while the tube 12 is opened. While the tube 12 is opened, a trigger signal is transmitted to a meter relay 22, and the pressure in the tube 12 which is detected by an atmospheric pressure sensor 17 is stored as a reference value. Then, after the inside of the tube 12 is depressurized while the tube 12 is closed, a semiconductor wafer is subjected to a film forming process. Then, with the tube 12 closed, the pressure in the tube 12 is restored to a specified value. The specified pressure is the reference value that is stored in the meter relay 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing technique, and more particularly to a technique that is effective when applied to the manufacture of a semiconductor device using a decompression processing apparatus having an atmospheric pressure sensor.

  In the manufacture of semiconductor devices such as LSI (Large Scale Integration), a CVD (Chemical Vapor Deposition) method is used for forming a polycrystalline silicon film, a silicon oxide film, a silicon nitride film, or the like. The low pressure CVD (LP-CVD) method, which is one of the CVD methods, has better film thickness distribution in the semiconductor wafer and better productivity than the film formed by the atmospheric pressure CVD method. It has the characteristics.

  Japanese Patent Application Laid-Open No. 5-283367 (Patent Document 1) discloses a technique for easily and accurately detecting the pressure in the hermetic treatment and satisfactorily opening the door of the hermetic chamber when the hermetic chamber is restored to normal pressure. ing.

Japanese Patent Application Laid-Open No. 6-349759 (Patent Document 2) discloses a technique for suppressing generation of particles and intrusion of air when opening a cap body of a heat treatment furnace after heat treatment of an object to be processed.
JP-A-5-283367 JP-A-6-349759

  The present inventors are examining a semiconductor device manufactured using a vertical LP-CVD apparatus 100 as shown in FIG.

  In the housing 11 of the LP-CVD apparatus 100, a processing chamber tube 12 to be sealed and a boat 13 for transporting semiconductor wafers into and out of the tube 12 are provided. An opening 14 serving as an entrance / exit of the boat 13 is provided below the tube 12, and a shutter 15 that opens and closes the tube 12 is provided in the vicinity of the opening 14. In addition, a cap 16 that closes the tube 12 when the boat 13 is inserted into the tube 12 is provided below the boat 13.

  On the other hand, outside the housing 11 of the LP-CVD apparatus 100, a vacuum pump 19 that depressurizes the inside of the tube 12 via an atmospheric pressure sensor 17 that detects whether or not the pressure in the tube 12 is atmospheric pressure, and a pipe 18. In addition, a device control unit 20 that performs control such as a film forming process in the tube 12 and a detection switch 24 that detects that the shutter 15 is open are provided.

  The atmospheric pressure sensor 17 has a zero-point adjustment (reference value setting) function that can be adjusted with a predetermined pressure as a reference, a display function that displays the pressure in the tube 12, and when the pressure in the tube 12 is atmospheric pressure. A meter relay 22 having a contact 21 for outputting a signal is connected.

  In addition, a vacuum pump 19 is connected to the pipe 18 via a main valve 23, and an atmospheric pressure sensor 17 is connected to be branched. In addition, a contact 21 and a detection switch 24 are connected to the device control unit 20. Although not shown, a valve (VENT valve) and piping for a system (VENT line) for opening the inside of the tube 12 to the atmosphere are connected to the tube 12.

  Next, a process of forming a film on the main surface of the semiconductor wafer using the LP-CVD apparatus 100 will be described. First, from a state where the shutter 15 is closed so that dust does not enter the tube 12, the boat 13 loaded with semiconductor wafers is inserted into the tube 12 with the shutter 15 opened, ie, with the tube 12 opened. . Next, after reducing the pressure in the tube 12 with the cap 16 closed, that is, with the tube 12 closed, a film forming process is performed on the semiconductor wafer. Next, an inert gas is introduced into the tube 12 with the cap 16 closed with the cap 16, and the atmospheric pressure sensor 17 is used so that the pressure inside the tube 12 becomes the same as the pressure outside the tube 12. To do. That is, the reduced pressure in the tube 12 is restored to the atmospheric pressure. Next, the boat 13 loaded with semiconductor wafers is pulled out from the tube 12 with the tube 12 opened.

  In a semiconductor device manufactured using the LP-CVD apparatus 100, appearance defects and characteristic defects may occur in inspection after processing of the LP-CVD apparatus 100 and inspection after completion of the semiconductor device. When such a defect occurs, the manufacturing yield of the semiconductor device is lowered.

  One possible cause of the occurrence of these defects is that foreign matter (particles) generated during film formation on the semiconductor wafer adheres to the tube 12 of the LP-CVD apparatus 100. For example, when the cap 16 is opened in order to take out the semiconductor wafer after film formation from the tube 12, the foreign matter may roll up and adhere to the semiconductor wafer. It is considered that the foreign matter is rolled up as described above when the cap 16 is opened with a large difference (pressure difference) between the pressure inside and outside the tube 12 being influenced by the air flow generated by the pressure difference. In order to prevent a pressure difference, the LP-CVD apparatus 100 is provided with the atmospheric pressure sensor 17 so that the pressure inside the tube 12 becomes the pressure outside the tube 12 and then the cap 16 is opened.

  However, when the zero point adjustment (reference value setting) of the atmospheric pressure sensor 17 is shifted to the minus side (decompression side), the atmospheric pressure (outside atmospheric pressure) is restored even if the pressure in the tube 12 is in a depressurized state. As a result, the VENT valve was opened and foreign matter was rolled up by the airflow from the VENT line and adhered to the semiconductor wafer. Further, when the atmospheric pressure sensor 17 is adjusted to the zero point and is shifted to the minus side (decompression side) and the main valve 23 is causing a minute leak, the boat 13 is pulled out of the tube 12 while the tube 12 is in a depressurized state. When the tube 12 was opened, an air flow was generated on the tube 12 side, and foreign matter rolled up and adhered to the semiconductor wafer. For this reason, in the inspection after the processing of the LP-CVD apparatus 100 and the inspection after the completion of the semiconductor device, an appearance defect and a characteristic defect occur, and the manufacturing yield of the semiconductor device is lowered.

  An object of the present invention is to provide a technique capable of improving the manufacturing yield of a semiconductor device using a decompression processing apparatus provided with an atmospheric pressure sensor.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The present invention relates to a sealed processing chamber, a boat for transferring semiconductor wafers to and from the processing chamber, a sensor for detecting atmospheric pressure in the processing chamber, and a pressure connected to the sensor to display the pressure in the processing chamber. A semiconductor device manufacturing technique using a decompression processing device having a meter relay for storing a pressure in the processing chamber by an external trigger signal. First, the boat is inserted into the processing chamber with the processing chamber open. Here, when the processing chamber is open, the trigger signal is sent to the meter relay, and the pressure in the processing chamber detected by the sensor is stored as a reference value. Next, after reducing the pressure in the processing chamber with the processing chamber closed, a film forming process is performed on the semiconductor wafer. Next, the pressure in the processing chamber is returned to a predetermined pressure with the processing chamber closed. The predetermined pressure is the reference value stored in the meter relay.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  According to the semiconductor device manufacturing technique of the present invention, it is possible to improve the manufacturing yield of a semiconductor device using a decompression processing apparatus having an atmospheric pressure sensor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
In the first embodiment, a manufacturing technique using a vertical LP-CVD apparatus in manufacturing a semiconductor device will be described with reference to FIGS. FIG. 1 is an explanatory view schematically showing a configuration of a vertical LP-CVD apparatus 10 shown in the first embodiment. FIG. 2 is a time chart of the LP-CVD apparatus shown in FIG. 1, and includes a wafer charging process, a boat loading process, a vacuuming process, a purging process, a film forming process, a purging process, an atmospheric pressure return process, a boat unloading process, and It is shown that the process is performed in the order of the wafer discharge process.

  Inside the housing 11 of the LP-CVD apparatus 10 are provided a tube 12 in a sealed processing chamber and a boat 13 for transporting semiconductor wafers into and out of the tube 12. An opening 14 serving as an entrance / exit of the boat 13 is provided below the tube 12, and a shutter 15 that opens and closes the tube 12 is provided in the vicinity of the opening 14. In addition, a cap 16 that closes the tube 12 when the boat 13 is inserted into the tube 12 is provided below the boat 13.

  On the other hand, outside the housing 11 of the LP-CVD apparatus 10, a vacuum pump 19 that depressurizes the inside of the tube 12 via an atmospheric pressure sensor 17 that inspects whether or not the pressure in the tube 12 is atmospheric pressure, and a pipe 18. In addition, an apparatus control unit 20 that performs control such as a film forming process in the tube 12 is provided. In addition, a zero point adjustment (reference value setting) function that can be adjusted based on a predetermined pressure, a display function that displays the pressure in the tube 12, and a signal when the pressure in the tube 12 is atmospheric pressure. A meter relay 22 having a contact 21 for output and a relay mechanism 25 having a relay 26 and a relay 27 are provided. The LP-CVD apparatus 10 is provided with a detection switch 24 that detects the open / closed state of the shutter 15.

  In addition, a vacuum pump 19 is connected to the pipe 18 via a main valve 23, and an atmospheric pressure sensor 17 is connected to be branched. In addition, a contact 21 and a detection switch 24 are connected to the device control unit 20. Although not shown, a valve (VENT valve) and piping for a system (VENT line) for opening the inside of the tube 12 to the atmosphere are connected to the tube 12.

  As shown in FIG. 2, the detection switch 24 is turned on when the shutter 15 is open. When the detection switch 24 is in the ON state, a zero set trigger signal is issued, and the relay 26 of the relay mechanism 25 is in the ON state. Since the contacts 26a and 26b operate in conjunction with the relay 26, when the relay 26 is in the ON state, the contacts 26a and 26b are also in the ON state. When the contact 26a is in the ON state, the relay 27 is in the ON state. Here, the contact 26b is connected to the device control unit 20, and the device control unit 20 can grasp the state of the contact 26b. In other words, when the contact 26b is in the ON state, the device control unit 20 can grasp that the shutter 15 is open.

  Thus, when the detection switch 24 is in the ON state, the relay 27 of the relay mechanism 25 is in the ON state. Since the contact 27a operates in conjunction with the relay 27, the contact 27a is also turned on when the relay 27 is turned on. The contact 27a is a time-decreasing contact that is turned off after a predetermined time (t seconds) from the ON state. For this reason, this contact point 27a connected to the meter relay serves as a trigger signal for setting the zero point (reference value) of the atmospheric pressure sensor 17.

  When the contact point 27a changes from the ON state to the OFF state after t seconds, the atmospheric pressure indicated by the display function of the meter relay 22 is adjusted to zero as the pressure in the tube 12 when the tube 12 is opened (reference value setting). To do. Here, when the pressure in the tube 12 is higher than the reference pressure (atmospheric pressure), the contact 21 of the meter relay 22 is in the ON state, and when lower than the reference value of atmospheric pressure, the contact 21 of the meter relay 22 is turned on. Is in an OFF state. Further, the contact 21 is connected to the device control unit 20, and the device control unit 20 can grasp the state of the contact 21. In other words, when the contact 21 is in the ON state, the device control unit 20 can grasp that the pressure in the tube 12 is atmospheric pressure.

  Next, a process of forming a film on the main surface of the semiconductor wafer using the LP-CVD apparatus 10 will be described. First, in the wafer charging process, a semiconductor wafer is mounted on the boat 13 with the shutter 15 closed (standby state) so that dust does not enter the tube 12. Next, in the boat loading process, the boat 13 on which the semiconductor wafer is mounted is inserted into the tube 12 with the shutter 15 opened, that is, with the tube 12 opened. Here, when the detection switch 24 is turned ON when the shutter 15 is opened, a trigger signal is sent to the meter relay 22, and the meter relay 22 sets the pressure in the tube 12 detected by the atmospheric pressure sensor 17 to zero ( As a reference value).

  Subsequently, in the evacuation step, the inside of the tube 12 is depressurized while the cap 16 is closed, that is, the tube 12 is closed. For this reason, the contact 21 of the meter relay 22 is turned off. Next, after purging, a source gas for film formation is supplied into the tube 12, and a film formation process is performed on the semiconductor wafer in the film formation process.

  Subsequently, in the atmospheric pressure recovery step, after purging and evacuation are repeatedly performed, an inert gas (for example, nitrogen gas) is continuously supplied into the tube 12. At this time, when the pressure in the tube 12 becomes the pressure of the zero point (reference value) stored in the meter relay 22, the contact 21 is turned on, and the apparatus control unit 20 has the pressure in the tube 12 at atmospheric pressure. Recognize that there is.

  Subsequently, in the boat unloading process, the boat 13 loaded with semiconductor wafers is pulled out from the tube 12 with the tube 12 opened. Next, in the wafer discharge process, the shutter 15 is closed and the semiconductor wafer is taken out from the boat 13.

  Since the LP-CVD apparatus 10 having such a configuration can automatically adjust the zero point for each batch, the pressure fluctuation at the time of detecting the atmospheric pressure return of the tube 12 after film formation and the pressure fluctuation at the time of opening the tube 12 are detected. Can be prevented. As a result, the generation of foreign matter due to pressure fluctuations in the tube 12 on the semiconductor wafer can be prevented, and the manufacturing yield of the semiconductor device can be improved.

(Embodiment 2)
In the second embodiment, a manufacturing technique using a vertical LP-CVD apparatus in manufacturing a semiconductor device will be described with reference to FIGS. FIG. 3 is an explanatory view schematically showing a configuration of the vertical LP-CVD apparatus 30 shown in the second embodiment. FIG. 4 is a time chart of the LP-CVD apparatus shown in FIG. 3, and includes a wafer charging process, a boat loading process, a vacuuming process, a purging process, a film forming process, a purging process, an atmospheric pressure return process, a boat unloading process, and It is shown that the process is performed in the order of the wafer discharge process. 5-8 is explanatory drawing which shows typically the LP-CVD apparatus in a manufacturing process. In the figure, reference numeral 31 is an isolation valve, reference numeral 33 is a supply pipe, reference numeral 34 is a valve, reference numeral 35 is a VENT pipe, reference numeral 36 is a VENT valve, reference numeral 37 is a pressure sensor, reference numeral 38 is an isolation valve, and reference numeral 39 is a pressure. Controller 40 is a valve.

  As shown in FIG. 3, the LP-CVD apparatus 30 of the second embodiment has an isolation valve 31 in the vicinity of the atmospheric pressure sensor 17 as compared with the LP-CVD apparatus 10 of the first embodiment. Is different. The isolation valve 31 is turned off when the source gas is supplied into the tube 12 in the film forming process, and is used to prevent the atmospheric pressure sensor 17 from being exposed to the source gas. is there. In addition, the description which overlaps with the said Embodiment 1 is abbreviate | omitted.

  Next, a process of forming a film on the main surface of the semiconductor wafer using the LP-CVD apparatus 30 will be described. First, in the wafer charging process, as shown in FIG. 5, a semiconductor wafer (not shown) is mounted on the boat 13 from a state where the shutter 15 is closed (standby state) so that dust does not enter the tube 12. At this time, the valve 34, the VENT valve 36, and the isolation valve 31 are open, and the main valve 23, the isolation valve 38, and the valve 40 are closed. Moreover, the vacuum pump 19 is always rotating. Further, the valve 34 and the VENT valve 36 are in an open state, and an inert gas (for example, nitrogen gas) is supplied into the tube 12 through the supply pipe 33, and the inert gas in the tube 12 passes through the VENT pipe. Exhausted.

  Subsequently, in the boat loading process, as shown in FIG. 6, the boat 13 on which the semiconductor wafer 1W is mounted is inserted into the tube 12 with the shutter 15 opened, that is, with the tube 12 opened. At this time, the valve 34, the VENT valve 36, and the isolation valve 31 are open, and the main valve 23, the isolation valve 38, and the valve 40 are closed. Moreover, the vacuum pump 19 is always rotating. Further, the valve 34 and the VENT valve 36 are in an open state, and an inert gas (for example, nitrogen gas) is supplied into the tube 12 through the supply pipe 33, and the inert gas in the tube 12 passes through the VENT pipe. Exhausted.

  When the detection switch 24 is turned on when the shutter 15 is opened in this way, a trigger signal is sent to the meter relay 22, and the meter relay 22 sets the pressure in the tube 12 detected by the atmospheric pressure sensor 17 to zero ( As a reference value).

  Subsequently, in the vacuuming step, the semiconductor wafer 1W is transferred into the tube 12, and the pressure in the tube 12 is reduced. First, the boat 13 is inserted into the tube 12 with the tube 12 opened, and the tube 12 is closed with the cap 16. Next, the vacuum pump 19 is evacuated with the valve 34 and the VENT valve 36 closed and the main valve 23 opened. The vacuum pump 19 is always rotating.

  Subsequently, in the film forming process, as shown in FIG. 7, after purging, a source gas for film forming is supplied into the tube 12, and the film forming process is performed on the semiconductor wafer. First, when evacuation is started and a certain pressure is exceeded, the isolation valve 38 of the pressure sensor 37 is opened. Next, the valve 40 is opened in order to obtain the film forming pressure, and the set pressure is maintained by receiving a signal from the pressure sensor 37 and controlling the flow rate of nitrogen by the pressure controller 39. Thereafter, the source gas is supplied into the tube 12 through the supply pipe 33 to perform film formation. At this time, the main valve 23, the valve 34, the isolation valve 38 and the valve 40 are in an open state, and the isolation valve 31 and the VENT valve 36 are in a closed state. Moreover, the vacuum pump 19 is always rotating.

  Here, an isolation valve 31 that operates in reverse to the isolation valve 38 of the pressure sensor 37 is installed on the tube 12 side of the atmospheric pressure sensor 17 (for example, when the isolation valve 38 is normally open, the isolation valve 31 is normally closed). The air for driving the valve branches from that of the isolation valve 38. Thereby, since the tube 12 and the atmospheric pressure sensor 17 are separated during film formation, reaction product adhesion to the atmospheric pressure sensor 17 can be prevented. Therefore, it is possible to prevent the zero-point adjustment shift of the meter relay 22 of the atmospheric pressure sensor 17 due to the reaction product adhesion.

  Subsequently, in the atmospheric pressure return process, after purging and evacuation are repeated, the main valve 23 is closed, an inert gas (for example, nitrogen gas) is supplied into the tube 12, and the pressure in the tube is changed to atmospheric pressure. Return to. At this time, the isolation valve 31, the valve 34, and the VENT valve 36 are open, and the main valve 23, the isolation valve 38, and the valve 40 are closed. Moreover, the vacuum pump 19 is always rotating.

  In the LP-CVD apparatus 100 examined by the present inventors, when the zero point adjustment (reference value setting) of the atmospheric pressure sensor 17 is shifted to the minus side (decompression side), the pressure in the tube 12 is reduced. Even so, it was recognized that the atmospheric pressure was restored, and the VENT valve 36 was opened and foreign matter was rolled up by the air flow from the VENT pipe 35 and adhered to the semiconductor wafer. However, since the LP-CVD apparatus 30 of the second embodiment can automatically adjust the zero point for each batch, it is possible to prevent pressure fluctuations when detecting return to atmospheric pressure of the tube 12 after film formation. . Further, even if the zero point adjustment shift is due to adhesion of reaction products, the isolation valve 31 is provided in the second embodiment, and therefore the zero point of the meter relay 22 of the atmospheric pressure sensor 17 is provided. Misalignment can be prevented.

  Subsequently, in the boat unloading step, as shown in FIG. 8, the boat 13 loaded with the semiconductor wafer 1 </ b> W is pulled out from the tube 12 with the tube 12 opened. At this time, the isolation valve 31, the valve 34, and the VENT valve 36 are open, and the main valve 23, the isolation valve 38, and the valve 40 are closed. Moreover, the vacuum pump 19 is always rotating.

  In the LP-CVD apparatus 100 studied by the present inventors, when the atmospheric pressure sensor 17 is shifted to the minus side (decompression side) in the zero point adjustment, and the main valve 23 causes a minute leak, the tube 12 is Since the boat 13 is pulled out from the tube 12 in a reduced pressure state, when the tube 12 is opened, an air flow is generated toward the tube 12 and foreign matter rolls up and adheres to the semiconductor wafer 1W. However, since the LP-CVD apparatus 30 of the second embodiment can automatically adjust the zero point for each batch, it is possible to prevent pressure fluctuations when detecting return to atmospheric pressure of the tube 12 after film formation. .

  Subsequently, in the wafer discharge process, the shutter 15 is closed and the semiconductor wafer 1W is taken out from the boat 13.

  Since the LP-CVD apparatus 30 having such a configuration can automatically adjust the zero point for each batch, the pressure fluctuation at the time of detecting the atmospheric pressure return of the tube 12 after film formation and the pressure fluctuation at the time of opening the tube 12 are detected. Can be prevented. Further, since the isolation valve 31 is provided, it is possible to prevent the zero-point adjustment shift of the meter relay 22 of the atmospheric pressure sensor 17 due to the reaction product adhesion. As a result, the generation of foreign matter due to pressure fluctuations in the tube 12 on the semiconductor wafer can be prevented, and the manufacturing yield of the semiconductor device can be improved.

(Embodiment 3)
In the third embodiment, a manufacturing technique using a vertical LP-CVD apparatus in manufacturing a semiconductor device will be described with reference to FIGS. FIG. 9 is an explanatory diagram schematically showing the configuration of the vertical LP-CVD apparatus 50 shown in the third embodiment.

  As shown in FIG. 9, the LP-CVD apparatus 50 according to the third embodiment has a PLC (programmable controller) 51, an AD input mechanism 52, and an alarm as compared with the LP-CVD apparatus 10 according to the first embodiment. It differs in that it has a mechanism 53 and does not have a meter relay 22. The PLC 51 and the AD input mechanism 52 operate in the same manner as the meter relay 22. The PLC 51 is connected to the device control unit 20, the detection switch 24, and the alarm mechanism 53, and the AD input mechanism 52 includes An atmospheric pressure sensor 17 is connected. Further, the alarm mechanism 53 warns the operator or the like to notify that the apparatus is in an abnormal state. In addition, the description which overlaps with the said Embodiment 1 is abbreviate | omitted.

  Next, a process of forming a film on the main surface of the semiconductor wafer using the LP-CVD apparatus 50 will be described with reference to FIG. FIG. 10 is a process flow of the PLC 51 included in the LP-CVD apparatus 50.

  First, whether or not the shutter 15 is open is determined by the detection switch 24. When the shutter 15 is open, the pressure in the tube 12 is detected by the atmospheric pressure sensor 17, and the pressure indicated by the atmospheric pressure sensor is detected by the PLC 51. DATA1 is stored with 0 as a reference point (reference value). That is, the boat 13 loaded with semiconductor wafers is inserted into the tube 12 from a state where the shutter 15 is closed so that dust does not enter the tube 12, with the shutter 15 opened (a state where the tube 12 is opened). When the inside of the tube 12 is open, the pressure in the tube 12 is stored as a reference value (DATA1).

  Subsequently, when the pressure in the tube 12 detected by the atmospheric pressure sensor 17, that is, DATA 1 is not within the measurement range of the atmospheric pressure sensor 17, specifically when it is ± 10% or less of the measurement range of the atmospheric pressure sensor 17. An alarm is issued. At this time, it is considered that the reaction product is excessively attached to the atmospheric pressure sensor 17. Therefore, maintenance, inspection, etc. of the atmospheric pressure sensor 17 are performed so as to be within a normal measurement range, and adhesion of the reaction product to the atmospheric pressure sensor 17 is prevented. Misalignment of point adjustment can be prevented.

  Subsequently, when the pressure in the tube 12 is within the normal measurement range, it is detected that the pressure in the tube 12 is atmospheric pressure. Next, after reducing the pressure in the tube 12 with the cap 16 closed, that is, with the tube 12 closed, a film forming process is performed on the semiconductor wafer. During film formation, the pressure in the tube 12 is monitored by a pressure sensor (not shown) different from the atmospheric pressure sensor 17.

  Subsequently, an inert gas is introduced into the tube 12 in a state where the tube 12 is closed with the cap 16, and the atmospheric pressure sensor 17 is used so that the pressure inside the tube 12 becomes approximately the same as the pressure outside the tube 12. To. That is, the pressure in the tube 12 is detected by the atmospheric pressure sensor 17 and returned to the pressure (atmospheric pressure) of the reference value (DATA1) stored previously.

  Subsequently, with the tube 12 opened, the boat 13 loaded with semiconductor wafers is pulled out of the tube 12 and the semiconductor wafer is taken out. At this time, the PLC 51 waits until the next trigger signal.

  Since the LP-CVD apparatus 50 having such a configuration can detect the abnormality of the atmospheric pressure sensor 17 for each batch, the pressure fluctuation at the time of detecting the atmospheric pressure return of the tube 12 after film formation and the pressure when the tube 12 is opened. Variations can be prevented. As a result, the generation of foreign matter due to pressure fluctuations in the tube 12 on the semiconductor wafer can be prevented, and the manufacturing yield of the semiconductor device can be improved.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, in the above-described embodiment, the case where the vertical LP-CVD apparatus is applied has been described. However, if the apparatus performs processing in a state where the inside of the processing apparatus is decompressed (decompression processing apparatus), the horizontal LP-CVD apparatus is used. The present invention can also be applied to an apparatus, a vacuum deposition apparatus, and the like.

  The present invention is widely used in the manufacturing industry for manufacturing semiconductor devices.

It is explanatory drawing which shows typically the structure of the vertical LP-CVD apparatus used at the manufacturing process of the semiconductor device shown in Embodiment 1 of this invention. It is a time chart of the manufacturing process using the LP-CVD apparatus shown in FIG. It is explanatory drawing which shows typically the structure of the vertical LP-CVD apparatus used at the manufacturing process of the semiconductor device shown in Embodiment 2 of this invention. It is a time chart of the manufacturing process using the LP-CVD apparatus shown in FIG. It is explanatory drawing which shows typically the LP-CVD apparatus in the manufacturing process of this Embodiment 2. FIG. It is explanatory drawing which shows typically the LP-CVD apparatus in the manufacturing process following FIG. It is explanatory drawing which shows typically the LP-CVD apparatus in the manufacturing process following FIG. It is explanatory drawing which shows typically the LP-CVD apparatus in the manufacturing process following FIG. It is explanatory drawing which shows typically the structure of the vertical LP-CVD apparatus used at the manufacturing process of the semiconductor device shown in Embodiment 3 of this invention. It is a processing flow of PLC shown in FIG. It is explanatory drawing which shows typically the structure of the vertical LP-CVD apparatus used in the manufacturing process of the semiconductor device which the present inventors examined.

Explanation of symbols

1W Semiconductor wafer 10 LP-CVD apparatus 11 Housing 12 Tube 13 Boat 14 Opening part 15 Shutter 16 Cap 17 Atmospheric pressure sensor 18 Pipe 19 Vacuum pump 20 Device control part 21 Contact 22 Meter relay 23 Main valve 24 Detection switch 25 Relay mechanism 26 Relay 26a, 26b Contact 27 Relay 27a Contact 30 LP-CVD apparatus 31 Isolation valve 33 Supply pipe 34 Valve 35 VENT pipe 36 VENT valve 37 Pressure sensor 38 Isolation valve 39 Pressure controller 40 Valve 50 LP-CVD apparatus 51 PLC
52 AD Input Mechanism 53 Reporting Mechanism 100 LP-CVD Equipment

Claims (5)

A sealed processing chamber;
A boat for transferring semiconductor wafers into and out of the processing chamber;
A sensor for detecting atmospheric pressure in the processing chamber;
A pressure reducing device having a meter relay connected to the sensor and displaying the pressure in the processing chamber and storing the pressure in the processing chamber by an external trigger signal,
(A) inserting the boat into the processing chamber with the processing chamber open;
(B) After the step (a), a step of reducing the pressure in the processing chamber with the processing chamber closed.
(C) After the step (b), performing a film forming process on the semiconductor wafer;
(D) after the step (c), the step of returning the pressure in the processing chamber to a predetermined pressure with the processing chamber closed;
(E) After the step (d), the step of pulling out the boat from the processing chamber with the processing chamber opened.
A method of manufacturing a semiconductor device including:
In the state in which the processing chamber of the step (a) is open, the trigger signal is sent to the meter relay, and the pressure in the processing chamber detected by the sensor is stored as a reference value.
The method for manufacturing a semiconductor device, wherein the reference value is the predetermined pressure in the step (d).   2. The semiconductor according to claim 1, wherein in the step (a), the trigger signal is sent to the meter relay when an inert gas is introduced into the processing chamber and the pressure in the processing chamber is stable. Device manufacturing method. Between the sensor and the processing chamber, an isolation valve is disposed on the sensor side,
2. The method of manufacturing a semiconductor device according to claim 1, wherein in the step (c), the isolation valve is closed.   4. The method of manufacturing a semiconductor device according to claim 3, wherein the isolation valve is closed while the source gas used in the film forming process in the step (c) is present in the processing chamber. A sealed processing chamber;
A boat for transferring semiconductor wafers into and out of the processing chamber;
A sensor for detecting atmospheric pressure in the processing chamber;
Using a decompression device connected to the sensor and having a controller having a reporting mechanism,
(A) inserting the boat into the processing chamber with the processing chamber open;
(B) After the step (a), a step of reducing the pressure in the processing chamber with the processing chamber closed.
(C) After the step (b), performing a film forming process on the semiconductor wafer;
(D) after the step (c), the step of returning the pressure in the processing chamber to a predetermined pressure with the processing chamber closed;
(E) After the step (d), the step of pulling out the boat from the processing chamber with the processing chamber opened.
A method of manufacturing a semiconductor device including:
A method of manufacturing a semiconductor device, characterized in that, when the processing chamber in the step (a) is open, the pressure is detected when the pressure in the processing chamber detected by the sensor is not within the measurement range of the sensor.

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