Container purging device

Abstract

The present invention provides a container purging device equipped with a miniaturized inert gas supply mechanism. [Solution] The load port as a container purging device includes a discharge mechanism that discharges gas from inside the carrier (container) 10 via a discharge section provided at the bottom of the carrier (container) 10, and a supply mechanism that supplies inert gas into the carrier via an injection section 102 provided at the bottom. By operating the discharge mechanism and the supply mechanism, the concentration of inert gas inside the substrate container is increased. The supply mechanism includes an injection nozzle 55 that is provided to be vertically movable from a mounting base, and a housing 541 that houses the injection nozzle 55 so that it can be vertically movable so that the injection nozzle contacts the injection section 102 of the carrier. The injection nozzle 55 acts as a piston with the housing 541 as a cylinder, enabling the injection nozzle 55 to be driven up and down. The housing 541 has an opening 541a through which the injection nozzle 55 passes, and a part of the injection nozzle 55 is exposed outside the housing and in contact with the injection section 102.

Description

Technical Field

[0001] The present invention relates to a container purge device capable of injecting gas into a container such as a carrier cassette that houses a semiconductor wafer substrate or a glass substrate in the manufacture of devices using semiconductor devices or glass substrates.

Background Art

[0002] In the manufacture of semiconductor devices, a carrier cassette that houses a plurality of wafers is used to transfer the semiconductor wafers between manufacturing apparatuses. Some carrier cassettes are sealed types called FOUPs (Front Opening Unified Pods) configured to be filled with an inert gas to prevent oxidation of the surface of the wafers.

[0003] Patent Document 1 discloses a technique for injecting an inert gas into a container such as a FOUP installed on a load port. In this technique, the load port is provided with a door and a door opening / closing mechanism for opening and closing the door. The door holds the lid of the container, and when the door is opened by the door opening / closing mechanism, the lid is removed from the main body of the container, and an inert gas is supplied from the exposed opening of the container (see, for example, paragraphs

[0018] ,

[0020] , and

[0024] of the specification of Patent Document 1).

[0004] <00000!5>In recent years, in order to increase the concentration of the inert gas in the container with the miniaturization of wiring patterns, a technique has also been adopted in which an injection part (inlet) of an inert gas is provided at the bottom of the container, and the inert gas is injected into the container from a nozzle that ejects the inert gas through the injection part.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to provide a container purging device equipped with a miniaturized inert gas supply mechanism for injecting and discharging gas into a container. [Means for solving the problem]

[0007] To achieve the above objective, a container purging device according to one embodiment of the present invention is a container purging device equipped with a mounting platform on which a substrate storage container capable of accommodating multiple substrates is placed, The container purging device comprises a discharge mechanism that discharges gas from within the substrate container via a gas discharge section provided at the bottom of the substrate container, and a supply mechanism that supplies inert gas into the substrate container via an injection section provided at the bottom, thereby increasing the concentration of the inert gas within the substrate container by operating the discharge mechanism and the supply mechanism. The supply mechanism includes an injection nozzle that is provided to be vertically movable from the stand described above, and a housing that houses the injection nozzle so as to be vertically movable so as to bring the injection nozzle into contact with the injection portion of the substrate housing container. The injection nozzle is configured to act as a piston with the housing as a cylinder, thereby enabling the injection nozzle to be driven up and down. The housing has an opening through which the injection nozzle passes, and a portion of the injection nozzle is exposed outside the housing and in contact with the injection portion. [Effects of the Invention]

[0008] As described above, the present invention makes it possible to miniaturize the supply mechanism. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing a load port as a container purging device according to a first embodiment of the present invention. [Figure 2] Figure 2 is a plan view showing the load port. [Figure 3] Figure 3 is a schematic cross-sectional view showing the main part of the mounting platform as seen from the side. [Figure 4] Figure 4 is a magnified cross-sectional view showing the area around the injection nozzle located on the front side of the load port. [Figure 5] Figure 5 shows the bottom of the carrier. [Figure 6] Figure 6 shows the state in which the injection nozzle is raised by the drive unit and the upper end of the injection nozzle is in contact with the grommet of the injection section. [Figure 7] Figure 7 is a cross-sectional view showing a lifting drive unit according to a second embodiment of the present invention, applied to a load port. [Modes for carrying out the invention]

[0010] In the apparatus employing the inert gas injection technology described above, a nozzle is provided on the container mounting platform at the load port. After the container is placed on the mounting platform and the nozzle contacts the injection port, the inert gas is injected into the container. Positioning pins are provided on the mounting platform to ensure that the container is placed in a predetermined position, and the container is positioned by fitting the positioning pins into grooves provided on the bottom of the container. Furthermore, to improve the airtightness of the nozzle to the injection port of the container during inert gas injection, the nozzle is positioned to protrude from the mounting platform, and the nozzle is elastically attached to the mounting platform by a spring. Specifically, when the container is placed on the mounting platform, the injection port of the container contacts the nozzle, and the weight of the container pushes the nozzle down against its spring force.

[0011] However, when a container is placed on the mounting platform, there is a problem in that the nozzle gets caught on or around the injection part before the container is positioned by the positioning pin, preventing the container from being positioned in the desired location.

[0012] Furthermore, since the nozzle adheres tightly to the container's injection port due to spring force, if the spring force is too strong, it may become impossible to accurately position the container vertically.

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0014] [First Embodiment] FIG. 1 is a perspective view showing a load port as a gas injection device according to a first embodiment of the present invention. FIG. 2 is a plan view showing the load port 100.

[0015] The load port 100 has a function of an interface between manufacturing apparatuses used in various manufacturing processes of semiconductor devices.

[0016] The load port 100 has a mounting table 2 on which a carrier 10 (carrier cassette), which is a container for accommodating a plurality of semiconductor wafer substrates (hereinafter referred to as wafers) W, is placed. The carrier 10 uses a FOUP (Front Opening Unified Pod) as a sealed container.

[0017] The mounting table 2 has a base housing 22 and a plate-shaped carrier base 21 provided on the base housing 22. The carrier 10 is placed on the carrier base 21. A passage opening 16 through which the wafer W passes is provided on the front side of the carrier 10 placed on the carrier base 21, that is, on the back side in the Y-axis direction in FIG. 1. An opening / closing device 15 for opening and closing the lid 105 of the carrier 10 is provided so as to face the passage opening 16.

[0018] The opening / closing device 15 mounts a key that is inserted into a keyhole (not shown) provided in the lid 105 of the carrier 10. By unlocking and locking using the key, the opening / closing device 15 opens and closes the lid​​​The carrier base 21 is movable in the Y-axis direction by a slider mechanism (not shown) provided within the base housing 22. Thereby, the carrier base 21 can move the carrier 10 placed thereon to a position where the opening / closing device 15 performs the operation of opening and closing the lid 105 of the carrier 10 as described above.

[0020] At the peripheral portion of the carrier base 21, three injection nozzles 5 (5a, 5b, 5c) for injecting an inert gas into the carrier 10 placed on the carrier base 21 are arranged, and one discharge nozzle 5' for discharging the gas within the carrier 10 is arranged. The injection nozzle 5 and the discharge nozzle 5' are each held by a nozzle holder 6. An attachment member 9 is connected to the nozzle holder 6, and the nozzle holder 6 is attached to a predetermined position at the peripheral portion of the carrier base 21 via the attachment member 9. Thereby, the injection nozzle 5 and the discharge nozzle 5' are movable integrally with the carrier base 21 by the above-described slider mechanism.

[0021] FIG. 3 is a schematic cross-sectional view showing the main part of the mounting table 2 as viewed from the side. An opening 221 is provided on the upper surface of the base housing 22 of the mounting table 2, and the injection nozzle 5 and the discharge nozzle 5' are provided so as to be exposed upward from within the base housing 22 through this opening 221. To these injection nozzles 5, elements necessary for supplying an inert gas, such as a supply source of an inert gas such as a gas cylinder (not shown), a pipe connected to this supply source, and an on-off valve connected to this pipe, are connected. A part of the pipe, the on-off valve, etc. are housed within the base housing 22. Further, the discharge nozzle 5' is connected to a blower or a vacuum pump via a pipe and an on-off valve. As the inert gas, nitrogen, helium, argon, etc. are used.

[0022] FIG. 4 is an enlarged cross-sectional view showing the vicinity of the injection nozzle | 5a provided, for example, on the front side (the rear side of the carrier 10) of the load port 100 among the three injection nozzles 5a, 5b, and 5c. This load port 100 is provided with an elevating drive unit 4 for elevating the injection nozzle 5a, respectively.

[0023] The three injection nozzles 5a, 5b, and 5c, the nozzle holder 6, and the lifting drive unit 4 are all identical in configuration. The discharge nozzle 5' is also equipped with the same nozzle holder 6 and lifting drive unit 4. Although there are slight differences in the configuration of the injection nozzle 5 and the discharge nozzle 5' in terms of their functions, they are essentially the same.

[0024] As shown in Figure 4, the lifting drive unit 4 has air cylinders 41, which are cylinder drive mechanisms driven by fluid pressure, attached to both sides of the nozzle holder 6. A mounting plate 42 is connected to the working end of the air cylinder 41, and an injection nozzle 5a is attached to the mounting plate 42. Therefore, the air cylinder 41 drives the mounting plate 42 to move up and down, thereby driving the injection nozzle 5a up and down.

[0025] The nozzle holder 6 has a main body 62 having a cylindrical recess 62a at its lower part, and a cover 61 provided on the main body 62 so as to close the recess 62a, and holds the injection nozzle 5a so as to be able to move up and down. The injection nozzle 5a has a flange portion 51 on its side, and is held in the nozzle holder 6 such that this flange portion 51 is positioned within the recess 62a of the nozzle holder 6. The cover 61, in relation to the flange portion 51 of the injection nozzle 5a, functions as a stopper for the upper limit position when the injection nozzle 5 moves upward due to the drive of the air cylinder 41. A flow path 52 is provided inside the injection nozzle 5a, and the lower part of the flow path 52 is connected to piping (not shown).

[0026] Furthermore, flexible piping is used within the base housing 22. Additionally, a spring may be provided on the lower surface of the flange portion 51 of the injection nozzle 5a as a support member for supporting the injection nozzle 5a. In this case, the function of this spring is not to press the injection nozzle against the injection portion 102 of the carrier 10 (see Figure 5) as in the conventional design, but simply to support the injection nozzle. Therefore, high design precision, such as designing a spring constant with an appropriate balance as described later, is not required.

[0027] As shown in Figures 2-4, the carrier base 21 is provided with multiple kinematic pins 7, which serve as positioning pins for positioning the carrier 10, protruding from the top of the carrier base 21. While there are, for example, three kinematic pins 7, the number is not limited to these. Additionally, a seating sensor 8 is installed on the carrier base 21 to detect whether or not the carrier 10 is positioned and placed on the carrier base 21. There may be multiple seating sensors 8.

[0028] Figure 5 shows the bottom of the carrier 10. Positioning grooves 101 are provided on the bottom 103 of the carrier 10, into which the kinematic pins 7 fit and engage, corresponding to the arrangement of the kinematic pins 7. In addition, injection sections 102 and discharge sections 102' are provided on the bottom 103, into which the injection nozzle 5 and discharge nozzle 5' make contact, respectively, corresponding to the arrangement of the nozzles 5 and 5'.

[0029] As shown in Figure 4, for example, the injection section 102 is provided with an opening 1021 in the bottom 103 of the carrier 10 and a grommet seal 1022 fitted into this opening 1021. The outer and inner diameters of the grommet seal 1022 are predetermined in relation to the diameter and outer diameter of the flow path 52 of the injection nozzle 5. The configuration of the discharge section 102' is substantially the same as that of the injection section 102.

[0030] As shown in Figure 4, the positioning groove 101 is V-shaped in cross-section, and the carrier 10 is positioned by the upper curved surface of the kinematic pin 7 making balanced contact with the opposing wall surfaces within the positioning groove 101.

[0031] The number and arrangement of the injection nozzles 5, discharge nozzles 5', and kinematic pins 7 provided in the load port 100 may be in any configuration, as long as they are consistent with the number and arrangement of the injection section 102, discharge section 102', and positioning grooves 101 provided in the carrier 10. The number and arrangement of these shall be in accordance with the standard.

[0032] The operation of the load port 100 configured as described above will now be explained.

[0033] For example, when an OHT (Over Head Transportation) or other transport robot (not shown) transports a carrier 10 containing wafers W from another location to this load port 100, the carrier 10 is placed on the mounting platform 2 of the load port 100. At this time, as shown in Figure 3, the carrier base 21 is located on the front side (right side in Figure 3). Also, as shown in Figure 4, the injection nozzle 5a (and other injection nozzles 5b, 5c and discharge nozzle 5') are waiting at the height of the standby position.

[0034] When the carrier 10 is transferred from the transport robot to the carrier base 21, the kinematic pin 7 and the positioning groove 101 of the carrier 10 work together to position the carrier 10 in a predetermined location. At this time, the seating sensor 8 detects that the carrier 10 has been placed in the predetermined location on the carrier base 21. Even when the carrier 10 is positioned in this way, as shown in Figure 4, the upper end of the injection nozzle 5 is not yet in contact with the injection section 102 of the bottom 103 of the carrier 10. In other words, the standby position of the injection nozzle 5 is such that the upper end of the injection nozzle 5 is lower than the position of the bottom 103 (especially the injection section 102) of the carrier 10 when the kinematic pin 7 is engaged with the positioning groove 101 and the carrier 10 is placed on the carrier base 21.

[0035] After the carrier 10 is positioned, that is, after the seating state of the carrier 10 is confirmed by the seating sensor 8, the injection nozzle 5 is raised by the drive of the lifting drive unit 4 as shown in Figure 6, and the upper end of the injection nozzle 5 contacts the grommet seal 1022 of the injection section 102. Then, the on-off valve described above opens, and inert gas supplied from a supply source (not shown) is injected into the carrier 10 via the injection nozzle 5 and the injection section 102. At substantially the same timing as this injection operation, the air inside the carrier 10 is discharged via the discharge section 102' and the discharge nozzle 5'. Alternatively, the air inside the carrier 10 may be partially removed via the discharge nozzle 5' first, reducing the pressure inside the carrier 10, before the inert gas is injected into the carrier 10.

[0036] After or while inert gas is being injected into the carrier 10, the carrier base 21 moves rearward (left side in Figure 3) along the Y-axis, causing the lid 105 of the carrier 10 to come into contact with the passage opening 16. The opening / closing device 15 then unlocks the lid 105 of the carrier 10 and removes the lid 105 from the body of the carrier 10, thereby creating communication between the inside of the carrier 10 and the inside of the manufacturing equipment via the passage opening 16. As a result, a transport robot (not shown) inside the manufacturing equipment takes out the wafer W from the carrier 10, and the manufacturing equipment performs predetermined processing on the wafer W.

[0037] Furthermore, after the wafers W have been processed, a transport robot within the manufacturing apparatus places the processed wafers W into the carrier 10 via the passage opening 16. When a predetermined number of wafers W have been placed in the carrier 10, the opening / closing device 15 attaches the lid 105 to the body of the carrier 10 and locks it in place. Then, the carrier base 21 moves forward along the Y-axis, returning the carrier 10 to the position in which it was initially placed on the carrier base 21.

[0038] Thus, in this embodiment, when the carrier 10 is placed on the carrier base 21, the kinematic pin 7 engages with the positioning groove 101 provided on the bottom 103 of the carrier 10, thereby positioning the carrier 10 on the mounting table 2. From this state, the lifting drive unit 4 causes the injection nozzle 5 and discharge nozzle 5' to contact the injection section 102 and discharge section 102' of the carrier 10, respectively. Therefore, the situation in which the injection nozzle 5 (or discharge nozzle 5') gets caught on the injection section 102 (or discharge section 102') of the carrier 10 before the carrier 10 is positioned on the mounting table 2 does not occur. In other words, according to this embodiment, the carrier 10 can be reliably positioned on the mounting table 2.

[0039] Furthermore, even if the injection nozzle 5 is elastically mounted to the carrier base 21 by the aforementioned support spring, and the spring force is too strong, the carrier 10 can still be positioned vertically on the carrier base 21 by appropriately controlling the driving force of the air cylinder 41. On the other hand, if the spring force is too weak, the contact force between the injection section 102 of the carrier 10 and the injection nozzle 5 will be insufficient, as described above. In other words, if a spring is provided in the injection nozzle, high design precision is required for the spring force, but since the driving force of the air cylinder 41 is controlled, such problems do not occur according to this embodiment.

[0040] In particular, when the carrier 10 is transported from above to the load port 100 using the OHT and placed on the mounting table 2, the carrier 10 mainly swings from side to side. In the conventional load port structure where the nozzle protrudes significantly from the mounting table due to spring force, the above-mentioned problems occurred, making positioning difficult. In this embodiment, even when the carrier 10 is transported by the OHT and swings from side to side, the injection nozzle 5e does not come into contact with the carrier 10 before positioning.

[0041] Furthermore, in particular, the use of a rubber grommet seal 1022 in the injection section 102 (or discharge section 102') results in a friction coefficient between the injection nozzle 5 and the grommet seal 1022 that is greater than the friction coefficient between the kinematic pin 7 and the positioning groove 101 of the carrier 10. Consequently, conventionally, the injection nozzle was prone to getting caught in the injection section of the carrier. Incidentally, the injection nozzle 5 is made of metal, the kinematic pin 7 is made of metal or resin, and the body of the carrier 10 is made of resin.

[0042] In this embodiment, as shown in Figure 4, the upper end of the injection nozzle 5 (or discharge nozzle 5') in the standby position is lower than the injection section 102 of the carrier 10 in the positioned state. Therefore, when positioning the carrier 10 on the mounting base 2, the injection nozzle 5 (or discharge nozzle 5') and the carrier 10 do not interfere with each other. This ensures that the carrier 10 is reliably positioned on the mounting base 2.

[0043] In this embodiment, an air cylinder 41 is used in the lifting drive unit 4. Unlike spring force, the air cylinder 41 provides a constant driving force regardless of the stroke length, making it easy to bring the injection nozzle 5 (or discharge nozzle 5') into contact with the injection section 102 (or discharge section 102') of the carrier 10 with the desired force. Furthermore, compared to other drive sources using electromagnetic motors, the air cylinder 41 has a simple configuration, and since it is driven by air pressure, the control is also simple, offering advantages in terms of lightness, maintainability, and durability.

[0044] [Second Embodiment] Figure 7 is a cross-sectional view showing a lifting drive unit according to a second embodiment of the present invention, which is applied to a load port in the same manner as described above. In describing this second embodiment, the same components and functions as those included in the load port 100 according to the first embodiment will be simplified or omitted, and the differences will be the focus of the description.

[0045] The lifting drive unit 54 includes a housing 541 for raising and lowering an injection nozzle 55. The injection nozzle 55 is provided such that a portion of it is exposed through an opening 541a provided on the upper surface of the housing 541. A flange portion 551 is formed on the outer circumferential surface of the injection nozzle 55. A cylindrical bellows 542 that supports the lifting and lowering movement of the injection nozzle 55 is connected between the flange portion 551 of the injection nozzle 55 and a connection portion 547 formed on the inner wall surface of the housing 541. This bellows 542 partitions the inside of the housing 541, forming two pressure chambers (first and second pressure chambers) 545 and 546. The two pressure chambers 545 and 546 are each provided with an introduction portion 543 for introducing inert gas into the pressure chamber 545 and an exhaust portion 544 for discharging the gas from the pressure chamber 546. The inert gas flow path 552 provided inside the injection nozzle 55 communicates with the inside of the pressure chamber 545.

[0046] In such a lifting drive unit 54, an inert gas is introduced into the pressure chamber 545, and air is discharged from the pressure chamber 546. This creates a pressure difference between the two pressure chambers 545 and 546. In this case, the introduction section 543 and the exhaust section 544 function as a pressure difference generating mechanism (pressure generation mechanism). By setting the flow resistance of the flow path 552 in the injection nozzle 55 to a relatively high level, it is possible to generate a pressure difference between the two pressure chambers 545 and 546.

[0047] When a pressure difference is generated between the two pressure chambers 545 and 546, the injection nozzle 55 rises and the bellows 542 extends, contacting the injection section 102 at the bottom 103 of the carrier 10. At this time, the gas pressure in the pressure chamber 545 is increased, so the inert gas in the pressure chamber 545 is injected into the carrier 10 through the flow path 552 and injection section 102 in the injection nozzle 55.

[0048] As described above, in this embodiment, by generating a pressure difference in pressure chambers 545 and 546, the injection nozzle 55 connected to the bellows 542 is driven by that pressure difference. As a result, the injection nozzle 55 itself becomes the piston of the cylinder, which makes it possible to miniaturize the entire lifting drive unit 54.

[0049] Furthermore, since the lifting drive unit 54 drives the injection nozzle 55 by utilizing the operation of inert gas injection into the carrier 10, a separate pressure transmission medium is not required.

[0050] [Other embodiments] The embodiments of the present invention are not limited to those described above, and various other embodiments can be realized.

[0051] In the embodiments described above, an inert gas is injected into the carrier 10, but dry air may be injected into the carrier 10 instead of the inert gas.

[0052] In the above embodiments, an air cylinder 41 was used as the drive source for the lifting drive unit 4, but a ball screw, belt, rack and pinion, or electromagnetic linear actuator may also be used. Furthermore, the number of drive sources (air cylinder 41 in the above embodiments) is not limited to two, but may be one or three or more.

[0053] In the embodiments described above, the case in which the gas injection and discharge device is applied to the load port 100 has been explained, but the gas injection device can also be applied to a stocker for storing the carrier 10, or to other purge stations, etc.

[0054] In the embodiments described above, a semiconductor wafer substrate was given as an example of the object to be housed in the carrier 10, but it is not limited to this, and a glass substrate used in display devices, photoelectric conversion devices, etc., may also be used.

[0055] In the second embodiment described above, when generating a pressure difference between pressure chambers 545 and 546, active exhaust from the exhaust section 544 is not required; instead, an inert gas may simply be introduced into pressure chamber 545. In other words, the pressure chamber 546 may be naturally exhausted.

[0056] Alternatively, the introduction of inert gas from the introduction section 543 may be omitted, and exhaust gas may be performed from the exhaust section 544, with the inert gas being supplied to the injection nozzle 55 via a separate route. Furthermore, the lifting drive unit according to the second embodiment described above can also be applied to an exhaust nozzle that discharges gas. [Explanation of Symbols]

[0057] W...wafer 2… Mounting platform 4, 54... Lifting drive unit (equivalent to the drive unit) 5 (5a, 5b, and 5c), 55... Injection nozzle (equivalent to a nozzle) 5'... Discharge nozzle (equivalent to a nozzle) 7…Kinematic pin (equivalent to a positioning pin) 10…Carrier (equivalent to a container) 41... Air cylinder 100... Load port (equivalent to a device equipped with a gas injection device) 101…Positioning groove 102...Injection part 102'...Discharge section 103...bottom

Claims

[Claim 1] In a container purging device equipped with a mounting platform on which a substrate container capable of housing a substrate is placed, The container purging device is provided so as to protrude from the aforementioned stand and includes a positioning pin that engages with the bottom of the substrate housing container and an injection nozzle that can be raised and lowered from the aforementioned stand. The steps include raising the injection nozzle so as not to exceed the height of the positioning pin and bringing it into contact with the injection section provided at the bottom of the container, A method for purging a container, comprising the step of supplying an inert gas or dry air into the container through the injection port.

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