JP2014038888A - Mini-environment device, and inner atmosphere replacement method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to rapidly stabilize fluctuation in an atmosphere and suppress a use amount of a substitutional gas, while making it possible to consider a yield of wafers exposed to an atmosphere out of a threshold.SOLUTION: A mini-environment device comprises: a load port for opening/closing a cover of a closed vessel accommodating a wafer to retract the wafer from a conveyance path for the wafer; a conveyance robot for conveying the wafer from the closed vessel to a processing chamber for processing the wafer; a fan filter unit for cleaning a conveyance region for the wafer; a supply port for supplying a gas except the air by which an atmosphere in the device is replaced; and switching means which has a duct for circulating the atmosphere in the device inside the device and an exhaust port for ejecting the atmosphere outside the device, and switches a passage to the duct and the exhaust port.

Description

  The present invention relates to a mini-environment apparatus and an internal atmosphere replacement method thereof, and more particularly, to take out a wafer in a clean environment from a sealed container for storing the wafer and transport the taken-out wafer to a processing chamber. The present invention relates to a mini-environment device suitable for the above and a method for replacing the internal atmosphere thereof.

  In general, in a semiconductor manufacturing process using a wafer, fine foreign matter on the wafer causes various problems such as disconnection of a wiring pattern, short circuit, or change in semiconductor characteristics. Therefore, production is performed in a very clean clean room. For example, a φ300 mm wafer is housed in a sealed container with a lid filled with a clean atmosphere called FOUP (Front Opening Unified Pod) and transported between apparatuses.

  The FOUP is composed of a FOUP shell and a FOUP lid, and the FOUP lid is provided with a packing to shield the atmosphere in the FOUP from the outside air. The FOUP includes an IC tag and a barcode, and information on the FOUP and wafers in the FOUP is managed.

  In the mini-environment device, an opener called a load port that opens and closes the lid of the FOUP is installed, and in the load port, a bar code reader and an RFID (Radio Frequency Identification) reader are installed to identify the FOUP. .

  In the atmospheric transfer system between the processing chamber and stage that performs inspection and processing from the load port, it is shut off from the outside air by the processing chamber, and is managed in the space of the mini-environment device that is locally cleaned by the down flow by the fan filter unit. The wafer is transferred by the transfer robot.

  Since the wafer is transported in an atmosphere that is locally and extremely cleanly managed by the FOUP, load port, and mini-environment device, the cleanliness of the cleanroom itself can be reduced and the operating cost of the cleanroom can be reduced. In the semiconductor manufacturing process, in addition to the cleanliness of the atmosphere, there are a process that hates humidity and a process that hates oxygen. In these steps, the atmosphere in the apparatus is replaced with a gas that has little influence on the process, for example, nitrogen, dry air, or an inert gas, and the wafer is transferred and processed. In order to manage the substitution state of the atmosphere, judgment is made by measuring humidity and oxygen concentration according to the substitution gas.

  Further, with the miniaturization of semiconductor processes, the influence of pattern corrosion due to moisture and oxygen in the atmosphere increases, and the yield decreases. In order to prevent corrosion of this pattern, efforts are being made to replace the atmosphere of the wafer transfer path with nitrogen, dry air, or inert gas, which is a gas that has little influence on the process.

  In particular, in order to reduce the influence of corrosion due to the process of hating humidity and oxygen and the miniaturization of process patterns, the atmosphere in the FOUP is replaced with the atmosphere in the mini-environment apparatus.

  A technique for replacing the atmosphere in the FOUP by injecting and discharging the replacement gas from the lower surface of the FOUP with the FOUP disposed is disclosed in Patent Document 1, and when the FOUP door is opened with an opener, the atmosphere inside the FOUP is changed. The replacement technique is described in Patent Document 2 and Patent Document 3. Patent Document 4 describes a technique for replacing the atmosphere in the transport path of a mini-environment device that transports the inside of the device from the FOUP.

JP 2007-5604 A JP 2009-38073 A JP 2009-111404 A Japanese Patent Application Laid-Open No. 2004-200669

  By the way, the FOUP has its FOUP lid opened and closed by a load port, and the load port is controlled by a command from the mini-environment device. Since the FOUP and the load port are standardized by the standard of the semiconductor industry, the FOUP and the load port used for the mini-environment device can be freely combined.

  However, the method for replacing the atmosphere inside the FOUP has not been standardized. An injection port and an exhaust port are prepared on the bottom surface of the FOUP, and the interior atmosphere is replaced by using the replacement port and the exhaust port on the bottom surface of the FOUP of the load port. There are individual methods such as a lower surface replacement method and a front surface replacement method in which gas is injected into the FOUP to replace the atmosphere when the FOUP lid is opened.

  On the semiconductor device side, the FOUP to be used in the production line cannot be specified, and the load port and the mini-environment device must maintain the replacement performance of the atmospheric transfer atmosphere in the combination thereof.

  Further, the completion of the replacement of the atmosphere in the FOUP is monitored by the injection flow rate and time, or the oxygen concentration and humidity of the discharged FOUP internal atmosphere. However, the atmosphere in the FOUP is not uniform due to the number of wafers stored in the FOUP. Therefore, the FOUP combined with the mini-environment device and the influence on the atmosphere of the mini-environment device when carrying out the wafer from the FOUP by the load port are not the same.

  In addition, in the method of replacing the atmosphere from the atmosphere inside the mini-environment device, a discharge method in which a replacement gas flows in from above the fan filter unit and flows out from below the wafer transfer area, and a replacement gas flows from above the fan filter unit. There is a circulation system that flows in and leads from below the wafer transfer area to the upper part of the fan filter unit. Even in these combinations, the influence on the atmosphere of the mini-environment device is different when the FOUP atmosphere and the mini-environment atmosphere are connected. .

  In the lower surface replacement method, the internal atmosphere is replaced without opening the FOUP lid. Therefore, when the FOUP lid is opened and the atmosphere in the FOUP and the atmosphere in the mini environment are mixed, the influence on the internal atmosphere of the mini-environment device is small. On the other hand, in the front replacement method, replacement is performed in a state where the FOUP lid is opened and connected to the atmosphere in the mini-environment, so the atmosphere discharged from the FOUP also flows into the mini-environment device.

  If the air replacement method of the mini-environment device is the discharge method, even if air flows into the mini-environment device from the load port, it will be exhausted by the down flow by the fan filter unit, so the effect is small. However, there is a drawback that the amount of replacement gas used is large.

  In addition, if the atmosphere replacement method of the mini-environment device is a circulation system, there is an advantage that the amount of replacement gas used is small. However, the atmosphere flowing into the mini-environment device from the load port is circulated upstream of the fan filter unit. Therefore, there is a difficulty that has a great influence.

  As described above, it is a problem to stably replace the internal atmosphere of the mini-environment apparatus with the atmosphere and reduce the amount of the replacement gas used. Further, since one or more load ports are installed in the mini-environment apparatus and a plurality of FOUPs are processed, when an abnormality in the mini-environment apparatus atmosphere is detected, there is already a wafer being processed. In a device that replaces the internal atmosphere of the mini-environment device, the oxygen concentration and humidity are monitored and transportation is permitted.If the oxygen concentration and humidity deviate from the specified threshold values, the device stops. Therefore, there is a problem that the wafer being processed is exposed to the atmosphere deviating from the specified threshold value by stopping the conveyance. Furthermore, when the apparatus becomes abnormal and maintenance work is required, the danger of oxygen deficiency arises for the operator due to the replacement of the air atmosphere inside the mini-environment apparatus.

  The present invention has been made in view of the above-mentioned points, and the object of the present invention is to quickly stabilize the fluctuation of the atmosphere and to suppress the use amount of the replacement gas. It is an object of the present invention to provide a mini-environment apparatus and a method for replacing the internal atmosphere of the wafer that has been exposed to the above.

  In order to achieve the above object, the mini-environment apparatus of the present invention opens and closes a lid of a sealed container in which a wafer is housed, and loads the wafer from the sealed container. A transfer robot for transferring to a processing chamber for processing the wafer, a fan filter unit for cleaning the transfer area of the wafer, and a supply port for supplying a gas for replacing the atmosphere in the apparatus with a gas other than the atmosphere And a duct for circulating the atmosphere inside the apparatus and a discharge port for discharging the atmosphere to the outside of the apparatus, and switching means for switching the flow path to the duct and the discharge port.

  Further, the internal atmosphere replacement method of the mini-environment apparatus of the present invention, in order to achieve the above object, a load port that opens and closes a lid of a sealed container in which a wafer is housed and retreats from the wafer transfer path, Replacing the internal atmosphere of a mini-environment device comprising a transfer robot for transferring the wafer from the sealed container to a processing chamber for processing the wafer, and a fan filter unit for cleaning the transfer area of the wafer. When the oxygen concentration in the mini-environment device rises above a predetermined value, the atmosphere in the mini-environment device is discharged from the discharge port, and the oxygen concentration in the mini-environment device is predetermined. When lower than the value, the atmosphere in the mini-environment device is internally circulated through the duct, One, and supplying the replacement gas into the mini-environment within the apparatus from a supply port said connected above the fan filter unit. In addition, when the atmosphere in the mini-environment apparatus deviates from a predetermined threshold, the risk is judged based on the exposure time of the wafer and the amount deviating from the threshold, and the mini-environment apparatus reports to the host apparatus. An environment device and an internal replacement method thereof are proposed.

  According to the present invention, it is possible to quickly stabilize the fluctuation of the atmosphere and suppress the use amount of the replacement gas, and it is possible to examine the yield of the wafer exposed to the atmosphere out of the threshold. There is a possible effect.

1 is a side view showing a partial cross-sectional view of a schematic configuration of an atmospheric transfer system in a general semiconductor wafer processing apparatus to which a mini-environment apparatus of the present invention is applied. It is a side view showing a general schematic configuration of a load port lower surface replacement system in a partial cross section. It is a side view which shows a general schematic structure of the front face substitution system of a load port partially in section. It is a side view which shows a partial cross section of the general schematic configuration of the circulation type replacement system in the mini-environment device. It is a side view which shows a general schematic structure of the discharge type replacement system in a mini-environment device in a partial cross section. BRIEF DESCRIPTION OF THE DRAWINGS It is Example 1 of the mini-environment apparatus of this invention, and is a side view which shows the state combined with the load port of a lower surface replacement system partially in cross section. It is Example 2 of the mini-environment apparatus of this invention, and is a side view which shows the state combined with the load port of a front displacement system in partial cross section. It is a figure which shows the relationship between the miniviriment device of this invention, and a process management control part. It is a figure which shows the relationship between the replacement system and management value in this invention. It is a graph for demonstrating the risk evaluation at the time of abnormality in this invention. It is a top view which shows partially Example 1 of the mini-environment apparatus of this invention. It is a logic circuit diagram for demonstrating the safety measure in this invention. It is a perspective view which shows the detail of the louver mechanism used in Examples 1 and 2 of the mini-environment device of the present invention. It is a perspective view which shows the detail of the valve mechanism used in Example 1 and 2 of the mini-environment apparatus of this invention.

  Hereinafter, an embodiment of a mini-environment device and an internal atmosphere replacement method thereof according to the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is used for the same component.

  FIG. 1 shows a schematic configuration of an atmospheric transfer system in a general semiconductor wafer processing apparatus to which the present invention is applied.

  As shown in the figure, the atmospheric transfer system in the semiconductor wafer processing apparatus includes a FOUP shell 3 and a FOUP lid 5, a FOUP 2 for transferring the wafer 1, a load port 6 for opening and closing the FOUP lid 5 of the FOUP 2, and the inside of the FOUP 2 A mini-environment having a fan filter unit 9 comprising a transfer robot 12 for transferring the wafer 1, a frame 14 for isolating from the external atmosphere, a fan 10 for generating a clean downflow in the isolated atmosphere, and a filter 11. The apparatus 100 is schematically configured by an apparatus 100 and a processing chamber 13 for performing inspection and processing as a transfer destination. Further, the FOUP lid 5 has a packing 4 so that the atmosphere in the FOUP 2 is sealed. Depending on the apparatus, the processing chamber 13 may be a stage or a vacuum preparatory chamber for performing processing or inspection in a vacuum.

  FIG. 2 shows a general schematic configuration of the lower surface replacement method of the load port 6.

  As shown in the figure, the FOUP 2 is installed and held on the mount base 7 of the load port 6 and the FOUP lid 5 is closed. In addition, it is provided with an injection port 21 from the mount base 7 to the bottom surface of the FOUP 2 and an exhaust port 23 for exhausting the replacement gas 22 from the bottom surface of the FOUP 2 to the mount base 7, and by opening the valve of the injection port 21. The replacement gas 22 is injected into the FOUP 2 from the injection port 21 and the internal atmosphere in the FOUP 2 is discharged as the exhaust gas 24 from the exhaust port 23, whereby the internal atmosphere in the FOUP 2 is replaced. Most of the exhaust gas 24 is initially the atmosphere, and most of the exhaust gas 24 becomes the replacement gas 22 as time passes.

  FIG. 3 shows a general schematic configuration of the front face replacement method of the load port 6.

  As shown in the figure, the FOUP 2 is installed and held on the mount base 7 of the load port 6, and after the FOUP lid 5 has advanced to the open / close position, it is attracted to the vacuum chuck of the door 8 to lock the FOUP lid 5. To unlock. The description of the vacuum chuck and the lock opening / closing mechanism is omitted.

  In FIG. 3, the FOUP lid 5 is opened, the transfer robot 12 is retracted downward so that the wafer 1 in the FOUP 2 can be accessed, and the replacement gas 26 is injected from the injection nozzle 25 through the opening of the FOUP shell 3. The exhaust gas 27 is discharged from the three openings by the down flow of the mini-environment device 100. Most of the exhaust gas 27 is initially air, and most of the exhaust gas 27 becomes a replacement gas with the passage of time.

  FIG. 4 shows a general schematic configuration of the circulation type replacement method in the mini-environment apparatus. The figure shows that the load port 6 of the lower surface replacement type is connected to the mini-environment device 100, the replacement of the internal atmosphere in the FOUP 2 is completed, the injection port 21 and the exhaust port 23 are accommodated in the mount base 7, and the FOUP lid 5 The FOUP cover 5 is opened to the open / close position, and the transfer robot 12 is retracted downward so that the wafer 1 in the FOUP 2 can be accessed.

  In FIG. 4, a supply port 32 for injecting a replacement gas is connected above the fan filter unit 9, and a pressure gauge 31 and an injection valve 30 for monitoring the supply state of the replacement gas are connected. The pressure gauge 31 may be a flow meter.

  Then, the replacement gas is injected upstream of the fan filter unit 9 to create a clean downflow. The base 15 of the mini-environment device 100 is formed with an opening connected to the duct 33 on the wall surface, and the replacement gas is circulated upstream of the fan filter unit 9 through the duct 33 on the wall surface. The atmosphere inside the mini-environment device 100 is monitored by the oxygen concentration meter 19, and the replacement valve 10 is controlled while observing the oxygen concentration meter 19, and the interior of the mini-environment device 100 is cleaned in the atmosphere. Maintained. The oxygen concentration meter 19 may be a hygrometer.

  FIG. 5 shows a general schematic configuration of the discharge type replacement method in the mini-environment apparatus. The figure shows that the front-replacement type load port 6 is connected to the mini-environment device 100, the FOUP 2 is installed and held on the mount base 7, and the FOUP lid 5 is advanced to the open / close position, and is then attracted to the vacuum chuck of the door 8. The FOUP lid 5 is unlocked by the lock opening / closing mechanism, the FOUP lid 5 is opened, the transfer robot 12 is retracted downward so that the wafer 1 in the FOUP 2 can be accessed, and the injection nozzle 25 is opened from the opening of the FOUP shell 3. The replacement gas 22 is injected from above, and the exhaust gas 27 is discharged from the opening of the FOUP shell 3. Most of the exhaust gas 27 is initially air, and most of the exhaust gas 27 becomes a replacement gas with the passage of time. The description of the vacuum chuck and the lock opening / closing mechanism is omitted.

  In FIG. 5, a supply port 32 for injecting the replacement gas 22 is connected above the fan filter unit 9, and a pressure gauge 31 and an injection valve 30 for monitoring the supply state of the replacement gas 22 are connected. The pressure gauge 31 may be a flow meter.

  A clean down flow is created by the fan filter unit 9, and the exhaust gas 27 exhausted from the opening of the FOUP shell 3 is exhausted through the exhaust port 36 of the base 15. The atmosphere of the mini-environment apparatus 100 is monitored by the oxygen concentration meter 19, and the replacement atmosphere injection valve 30 is controlled while observing the oxygen concentration meter 19, and the interior of the mini-environment device 100 is cleaned with the atmosphere replaced. Maintained. The oxygen concentration meter 19 may be a hygrometer.

  FIG. 6 shows a first embodiment of the mini-environment device according to the present invention, which is combined with the load port 6 of the lower surface replacement type, and is a diagram in which the FOUP 2 is transported and installed in the first embodiment of the mini-environment device 200 according to the present invention. Yes, the lower surface replacement type load port 6 is connected to the mini-environment device 200, the replacement of the atmosphere in the FOUP 2 is completed, the injection port 21 and the exhaust port 23 are accommodated in the mount base 7, and the FOUP lid 5 is opened and closed. The FOUP lid 5 is opened and the transfer robot 12 is retracted downward so that the wafer 1 in the FOUP 2 can be accessed.

  As shown in the figure, the mini-environment apparatus 200 according to the present embodiment stores the wafer 1 in the FOUP 2 with the FOUP lid 5, opens and closes the FOUP lid 5 in the FOUP 2 with the FOUP lid 5, and retreats from the transfer path of the wafer 1. A transfer port 12 for transporting the wafer 1, a transport robot 12 for transporting the wafer 1 from the FOUP 2 with the FOUP lid 5, and transporting the wafer 1 to a processing chamber (not shown) for processing the wafer 1. The fan filter unit 9 to be cleaned, and in this embodiment, has a gas supply port 32 for replacing the atmosphere in the mini-environment device 200 with a gas other than the atmosphere, and the mini-environment device 200 It has a duct 33 that circulates the inside atmosphere inside the device and an exhaust port 36 that exhausts it outside the device. A valve 35 and louvers 34 for switching the flow path to those ducts 33 and the outlet 36, characterized in that is. The details will be described below.

  In FIG. 6, the atmosphere in the frame 14 is downflowed by the fan filter unit 9 and flows downward while managing the transfer area of the wafer 1 cleanly and sucked by the fan 10 of the fan filter unit 9 through the duct 33. Circulates upstream of unit 9. On the other hand, an injection valve 30 for supplying a replacement gas when the oxygen concentration increases, a pressure gauge 31 for monitoring the state of the replacement gas, and an external replacement gas supply port 32 are connected above the fan filter unit 9. . The pressure gauge 31 may be a flow meter.

  The duct 33 for circulating the atmosphere in the mini-environment device 200 is provided with a valve 35. By opening and closing the valve 35, the circulating atmosphere can be flowed or stopped. In addition, a controllable louver 34 is installed on the bottom surface of the base 15, and by opening and closing the louver 34, the internal atmosphere of the frame 14 is discharged from the exhaust port 36 by the down flow of the fan filter unit 9, or stopped. can do. The atmosphere in a state where the louver 34 closes the exhaust port 36 and the valve 35 of the duct 33 is open is a state in which control is performed while circulating inside the frame 14. Further, an upper oxygen concentration meter 38 is installed in the transfer region of the wafer 1 and a lower oxygen concentration meter 39 is installed in the lower portion of the transfer region of the wafer 1 inside the frame 14 to monitor the atmospheric substitution state inside the mini-environment device 200. doing.

  The oxygen concentration meter has a threshold A, threshold B, threshold C, and threshold D from the lowest concentration, as shown in FIG. When the oxygen concentration in the circulating atmosphere rises to the threshold value B, the injection valve 30 for injecting the replacement gas is opened, the replacement gas is supplied to the inside of the frame 14, and when the oxygen concentration returns to the threshold value A, the replacement is performed. Stop supplying gas.

  By adopting such a configuration of the present embodiment, the atmosphere inside the mini-environment device 200 is discharged or circulated, so that the change in the atmosphere can be quickly stabilized and the amount of replacement gas used can be suppressed. It becomes possible.

  FIG. 7 shows a second embodiment of the mini-environment device according to the present invention, and is a view in which the FOUP 2 is transported to the second embodiment of the mini-environment device 300 according to the present invention in combination with the front-replacement type load port 6. .

  In this embodiment shown in the figure, the FOUP 2 is installed and held on the mount base 7, the FOUP lid 5 is advanced to the open / close position, and is attracted to the vacuum chuck of the door 8, and the FOUP lid 5 is unlocked by the lock opening / closing mechanism. After the FOUP lid 5 is opened and the transfer robot 12 is retracted downward so that the wafer 1 in the FOUP 2 can be accessed, the replacement gas 22 is injected into the FOUP 2 from the injection nozzle 25 through the opening of the FOUP shell 3, and the FOUP shell 3 shows a state in which the replacement gas is discharged as the exhaust gas 24 from the opening 3. Most of the exhaust gas 24 is initially air, and most of the exhaust gas 24 becomes a replacement gas as time passes. The description of the vacuum chuck and the lock opening / closing mechanism is omitted.

  Similarly to the first embodiment, the mini-environment device 300 of the present embodiment also has a gas supply port 32 that replaces the atmosphere in the mini-environment device 300 with a gas other than the atmosphere, and the mini-environment device 300 Characterized in that it has a duct 33 that circulates the atmosphere in the apparatus and an exhaust port 36 that discharges the atmosphere to the outside of the apparatus, and a valve 35 and a louver 34 that switch the flow path to the duct 33 and the exhaust port 36. To do. The details will be described below.

  In FIG. 7, the exhaust gas 24 discharged from the FOUP 2 flows into the frame 14. Most of the exhaust gas 24 is initially air, and most of the exhaust gas 24 becomes a replacement gas as time passes. The air flowing into the frame 14 flows down the transfer area of the wafer 1 by the downflow by the fan filter unit 9 and is detected by the lower oxygen concentration meter 39, and the oxygen concentration increases and reaches the threshold value C. At this time, there is no change in the upper oxygen concentration meter 38 installed in the transfer area of the wafer 1. When the lower oxygen concentration meter 39 senses an increase in oxygen concentration below the frame 14, the louver 34 on the bottom surface of the base 15 opens and an atmosphere containing a large amount of air is discharged from the exhaust port 36.

  Furthermore, the valve 35 installed in the duct 33 that circulates the atmosphere upstream of the fan filter unit 9 from the lower transfer area of the wafer 1 is closed, and the replacement gas injection valve 30 installed upstream of the fan filter unit 9 is opened. The downflow is generated by the injected replacement gas. At this time, the increase in the oxygen concentration of the upper oxygen concentration meter 38 installed in the transfer region of the wafer 1 can be made extremely small compared to the lower oxygen concentration meter 39 installed in the lower portion of the transfer region of the wafer 1.

  In other words, the transfer area of the wafer 1 is managed with almost no influence of the air discharged from the FOUP 2, and the oxygen concentration in the lower part is lowered to become the threshold value B over time. When the oxygen concentration reaches the threshold value B, the louver 34 at the bottom of the base 15 is closed, the valve 35 in the duct 33 is opened, and the atmosphere circulates inside the frame 14. When the oxygen concentration further decreases and reaches the threshold value A, the injection valve 30 is closed and the supply of the replacement gas is stopped.

  The atmosphere in the frame 14 is evaluated by the upper oxygen concentration meter 38 in the transfer area of the wafer 1, and the circulation system of the atmosphere of the mini-environment apparatus 300 is in the transfer area of the wafer 1 and the transfer area of the wafer 1. By performing both the upper oxygen concentration meter 38 and the lower oxygen concentration meter 39 installed at the lower side, it is possible to stably perform atmospheric replacement of the transfer region of the wafer 1.

  FIG. 8 shows the relationship between the mini-viroment apparatus of the present invention and the process management control unit. In FIG. 8, the process management control unit 48 instructs the ceiling suspended automatic transport vehicle 44 to carry the FOUP 2 to the load port 6 of the apparatus 47. The FOUP 2 includes a barcode 16 and an IC tag 17, and the FOUP 2 is identified by the barcode reader and the RFID reader 18 installed in the load port 6.

  The identification information of the FOUP 2 is sent from the load port 6 to the mini-environment transport system 45 and sent to the process management control unit 48 via the control unit of the apparatus main body 46. The process management control unit 48 instructs processes such as processing contents performed by the apparatus 47. From the apparatus 47, the result of the process and the content of the error that has occurred are sent to the process management controller 48.

  When the upper oxygen concentration meter 38 in the transfer area of the wafer 1 rises above the threshold value D, which is a specified value, the movement during the operation is terminated and the transfer is stopped. The status of the wafer 1 in the apparatus 47 is confirmed, the wafer 1 is stored in the same number of stages of the FOUP 2 that has been unloaded, and the FOUP lid 5 is closed. When the load port 6 has a purge function, the atmosphere in the FOUP 2 is replaced.

  As shown in FIG. 10, threshold values E and F in which the oxygen concentration has increased from the threshold value D are set, and the time required for storing the wafer 1 (exposure time) and the risk level from the atmospheric concentration are determined. From the low risk (level 1) of the error linked to the FOUP 2 that has been processed, the medium risk (level 2) and high risk (level 3) are issued. When the load port 6 does not have a replacement function, or when the load port 6 with the replacement function cannot replace the specified value, a risk extra large (level 4) is transmitted.

  At this time, if there is no abnormality in the fan filter unit 9 or the supply replacement gas amount, the replacement gas is injected by the discharge method. If there is an abnormality in the fan filter unit 9 or the supply gas amount, oxygen is used as the circulation method. Maintain the concentration. By sending the degree of error risk from the apparatus 47 to the process management control unit 48, the yield of the wafer 1 in the FOUP 2 can be predicted and the production volume can be managed.

  In FIG. 11, the top view of the mini-environment apparatus 200 of Example 1 mentioned above is shown.

  As shown in the figure, the frame 14 is provided with two load ports 6 on which the FOUP 2 is placed. FIG. 11 is a diagram in which the fan filter unit 9 is partly cut, showing an arrangement relationship of the safety switch 41 for monitoring the states of the transfer robot 12, the exhaust port 36, the duct 33, and the maintenance cover 40. On the upper surface of the unit 9, the arrangement relationship of the injection valve 30, the pressure gauge 31 and the supply port 32 can be seen.

  By the way, the safety switch 41 described above is prepared in the maintenance cover 40 of the mini-environment device 200, and the state of the maintenance cover 40 is monitored. In particular, when an error occurs in the mini-environment device 200 or the load port 6, in the mini-environment device 200 that performs air replacement, it is necessary to inform the worker that there is a risk of oxygen deficiency in the work atmosphere. There is.

  When the maintenance cover 40 is open, the apparatus cannot automatically operate. When the safety switch 41 detects that the maintenance cover 40 is open, the replacement gas injection valve 30 is closed. When the maintenance cover 40 is open and the oxygen concentration inside the mini-environment device 200 is 18% or less, which is a risk of oxygen deficiency as defined by regulations such as oxygen deficiency, a warning sound is emitted from the buzzer 43. The operator is informed of the danger through the flow and warning light 42.

  When the maintenance cover 40 is opened, the supply of the replacement gas is stopped, and the oxygen concentration in the atmosphere of the mini-environment apparatus 200 is restored to 18% or more, both the warning sound and the warning lamp are stopped. If there is an abnormality in the fan filter unit 9, there is a possibility that the exhaust inside the mini-environment device 200 may not be exhausted. Therefore, even if the oxygen concentration returns to 18% or more, a warning sound by the buzzer 43 and a warning light 42 A warning is issued.

  When the maintenance cover 40 is closed, the transfer robot 12 and the load port 6 perform an origin return operation, and accept automatic transfer when the atmosphere of the mini-environment device 200 returns to a specified value within a specified time. The logic circuit showing these is shown in FIG.

  FIG. 13 shows details of the louver mechanism used in the mini-environment devices 200 and 300 according to the first and second embodiments described above.

  As shown in the figure, the louver 34 constituting the louver mechanism opens and closes the exhaust port 36 formed in the base 15 of the mini-environment devices 200 and 300, but the cylinder 50 provided in the base 15 includes When the louver is lowered, the louver arm 52 is pulled downward while the cylinder shaft 51 slides in the louver arm 52, so that the louver 34 connected to the louver arm 52 rotates around the louver shaft 53. The exhaust port 36 is opened and closed. Another pair of louvers 34 are symmetrically installed on the cylinder shaft 51, and the other exhaust port 36 is also opened and closed in synchronization with the movement of the cylinder 50.

  FIG. 14 shows details of the valve mechanism used in the mini-environment devices 200 and 300 according to the first and second embodiments described above.

  As shown in the figure, the valve 35 constituting the valve mechanism opens and closes the duct 33 formed in the mini-environment devices 200 and 300. The operation is performed when the rotary actuator 56 rotates. Rotates, the valve 35 operates to open and close the duct opening 37 installed in the duct 33.

  According to such a present Example, the fluctuation | variation of the atmosphere inside a mini-environment apparatus can be rapidly stabilized by controlling the injection | pouring flow volume and discharge amount of a replacement gas, and the circulation amount.

  In addition, when an abnormal atmosphere in the mini-environment apparatus is detected, the wafer transfer is stopped, the wafer is being transferred and the wafer being processed is stored in the FOUP, and the atmosphere replacement operation in the FOUP is performed. The risk to the sample is ranked according to the state and time of the atmosphere exposed at that time and output to a higher-level device, and information on the risk to the wafer is sent to the control unit that manages the production process. The yield can be predicted and the production volume can be managed.

  Also, during maintenance, it is possible to judge the danger of the work atmosphere by detecting the cover status for maintenance, the status of the fan filter unit, and the status of the atmosphere inside the mini-environment device. Can inform you.

  Therefore, according to the present embodiment, it is possible to quickly stabilize the fluctuation of the atmosphere and suppress the use amount of the replacement gas, as well as to examine the yield of the wafer exposed to the atmosphere outside the threshold. It is also possible to protect the worker from the danger of oxygen deficiency due to the replacement gas during maintenance.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... FOUP, 3 ... FOUP shell, 4 ... Packing, 5 ... FOUP lid, 6 ... Load port, 7 ... Mount base, 8 ... Door, 9 ... Fan filter unit, 10 ... Fan, 11 ... Filter, DESCRIPTION OF SYMBOLS 12 ... Transfer robot, 13 ... Processing chamber, 14 ... Frame, 15 ... Base, 16 ... Bar code, 17 ... IC tag, 18 ... Bar code reader and RFID reader, 19 ... Oxygen meter, 21 ... Injection port, 22 ... Replacement gas, 23 ... Exhaust port, 24, 27 ... Exhaust gas, 25 ... Injection nozzle, 26 ... Replacement gas, 30 ... Injection valve, 31 ... Pressure gauge, 32 ... Supply port, 33 ... Duct, 34 ... Louver, 35 ... Valve, 36 ... Exhaust port, 37 ... Duct opening, 38 ... Upper oxygen meter, 39 ... Lower oxygen meter, 40 ... Maintenance cover, 41 ... Foot switch, 42 ... Warning light, 43 ... Buzzer, 44 ... Ceiling-suspended automatic transport vehicle, 45 ... Mini-environment transport system, 46 ... Main body, 47 ... Device, 48 ... Process management control unit, 50 ... Cylinder, DESCRIPTION OF SYMBOLS 51 ... Cylinder shaft, 52 ... Louver arm, 53 ... Louver shaft, 56 ... Rotary actuator, 58 ... Valve shaft, 100, 200, 300 ... Mini-environment device.

Claims (14)

  A load port that opens and closes a lid of a hermetic container in which the wafer is stored, and retreats from the wafer conveyance path; a conveyance robot that conveys the wafer from the hermetic container and conveys the wafer to a processing chamber for processing the wafer; A fan filter unit for cleaning the wafer transfer area, a supply port for supplying a gas for replacing the atmosphere in the apparatus with a gas other than the atmosphere, a duct for circulating the atmosphere in the apparatus inside the apparatus, and the outside of the apparatus A mini-environment device having a discharge port for discharging, and switching means for switching the flow path to the duct and the discharge port. The mini-environment device according to claim 1,
The switching means includes a louver mechanism that opens and closes the discharge port formed in a base of the mini-environment device and a valve mechanism that opens and closes the duct formed in the mini-environment device. Mini-environment device. The mini-environment device according to claim 2,
In the louver mechanism, when the cylinder provided in the base is lowered, the louver arm is pulled downward while the cylinder shaft slides in the louver arm, and the louver connected to the louver arm is centered on the louver shaft. A mini-environment device, wherein the exhaust port is opened and closed by rotating. The mini-environment device according to claim 2,
When the rotary actuator rotates, the valve mechanism rotates the valve shaft so that the valve operates to open and close the duct opening portion installed in the duct. The mini-environment device according to claim 1,
The supply port is connected above the fan filter unit, and an injection valve for supplying a replacement gas when the oxygen concentration in the apparatus rises, and a pressure gauge or a flow rate for monitoring the state of the replacement gas. A mini-environment device characterized in that a meter is installed. The mini-environment device according to any one of claims 1 to 5,
An upper oxygen concentration meter and a hygrometer are installed in the wafer transfer region, and a lower oxygen concentration meter is installed below the wafer transfer region, respectively, and the upper oxygen concentration meter, the hygrometer and the lower oxygen concentration meter are used to replace the atmosphere inside the apparatus. A mini-environment device characterized by monitoring a state. The mini-environment device according to claim 6,
In the upper and lower oxygen concentration meters, threshold A, threshold B, and threshold C are set from the lowest oxygen concentration. When the threshold is A, the atmosphere inside the apparatus is circulated. When the threshold is B, the atmosphere inside the apparatus is circulated. Then, when the threshold gas is at the threshold value C, the replacement gas is injected while the atmosphere inside the device is discharged, and when the circulating oxygen concentration rises to the threshold value B, the replacement gas is injected. When the injection valve is opened, a replacement gas is supplied to the inside of the apparatus, and when the oxygen concentration returns to the threshold A, the supply of the replacement gas is stopped, and the oxygen concentration in the apparatus is minimized while minimizing the consumption of the replacement gas. Mini-environment device characterized by rapidly stabilizing The mini-environment device according to claim 7,
The threshold value E and threshold value F in which the oxygen concentration is increased from the threshold value D of the oxygen concentration are set, and the risk of error associated with the sealed container that has been processed from the time required for storing the wafer and the concentration of the atmosphere is set to a level. A mini-environment device characterized in that the degree of risk of this error is divided and sent to the host device. The mini-environment device according to any one of claims 1 to 8,
The mini-environment device is provided with a maintenance cover, and a safety switch that monitors the state of the maintenance cover is installed. The safety switch detects that the maintenance cover is open, and the oxygen concentration inside the device is detected. A mini-environment device comprising a warning means for informing the danger when the value is 18% or less. The mini-environment device according to claim 9,
The mini-environment device, wherein the warning means is a buzzer through which a warning sound flows and / or a warning sound that generates a warning. A load port that opens and closes a lid of a sealed container in which the wafer is stored and retracts from the wafer transport path; a transport robot that transports the wafer from the sealed container and transports the wafer to a processing chamber for processing the wafer; When replacing the internal atmosphere of the mini-environment device provided with a fan filter unit for cleaning the wafer transfer area,
When the oxygen concentration in the mini-environment device has risen above a predetermined value, the atmosphere in the mini-environment device has been discharged from the outlet, and the oxygen concentration in the mini-environment device has dropped below the predetermined value. In this case, the atmosphere in the mini-environment device is internally circulated through a duct, and a replacement gas is supplied into the mini-environment device from a supply port connected above the fan filter unit. An internal atmosphere replacement method for a mini-environment device characterized by The internal environment replacement method for a mini-environment device according to claim 11,
The discharge of the atmosphere in the mini-environment device from the discharge port is performed by opening and closing a louver, and the internal circulation of the atmosphere in the mini-environment device through the duct closes the louver. A method for replacing the internal atmosphere of a mini-environment device, which is performed by opening and closing the duct with a valve. In the internal atmosphere replacement method of the mini-environment device according to claim 11 or 12,
An upper oxygen concentration meter and a lower oxygen concentration meter are respectively installed in the wafer transfer region and a lower region of the wafer transfer region, and the upper and lower oxygen concentration meters have threshold values A, B, Threshold C and threshold D are set, and when the circulating oxygen concentration rises to reach threshold B, the injection port for injecting the replacement gas is opened, and the replacement gas is supplied into the mini-environment device, When the oxygen concentration returns to the threshold A, the supply of the replacement gas is stopped. In the mini-environment device internal atmosphere replacement method according to any one of claims 11 to 13,
The mini-environment device is provided with a maintenance cover, and a safety switch that monitors the state of the maintenance cover is installed. The safety switch detects that the maintenance cover is open, and the oxygen concentration inside the device is detected. A method for replacing the internal atmosphere of a mini-environment device, wherein a warning is given by warning means when the value is 18% or less.

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