JP2006032528A - Single wafer stocker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single wafer stocker in which flat members such as a plurality of wafers can be stored in a minimum space for each sheet, and hence the flat members can be easily carried in and out.
Rotating members (15a, 15b) disposed in upper and lower portions on both sides of a flat plate member (3) in a transfer direction in a casing (10) provided with a carry-in port (11) and a carry-out port (12) of the flat plate member (3). The endless members 17a and 17b spanned between the rotating members and a plurality of support members 18a and 18b horizontally spanned across the transfer direction at a plurality of positions between the endless members on both sides. The pair of support devices 13a and 13b are installed at intervals so as to support both ends in the transfer direction of the flat plate member 3 by support members 18a and 18b adjacent to each other in the transfer direction, and the rotation member 15a of these support devices. , 15b is provided with a driving means for synchronously rotating in the reverse direction, so that the flat plate member 3 supported by the support members 18a, 18b is moved up and down.
[Selection] Figure 1

Description

  The present invention relates to a single wafer stocker for temporarily storing flat members such as semiconductor wafers one by one.

  For example, in a factory for manufacturing glass substrates for flat panel displays such as semiconductor wafers, LCDs (liquid crystal displays), PDPs (plasma displays), ELs (electroluminescent displays), etc., the semiconductor wafers, glass substrates, etc. A clean stocker is provided for temporarily storing them for time adjustment and the like in the process of transporting from one manufacturing process to another manufacturing process.

  A conventional clean stocker of this type is provided with a carry-in port and a carry-out port, and a plurality of shelves for storing cassettes containing wafers and the like on both sides of the interior filled with clean air (clean air). In the central part between these shelves, a stacker crane for loading and unloading cassettes to and from the shelves is provided between the shelves and the carry-in and carry-out ports, and on the rear side of each shelf, A fan filter unit is provided for flowing purified air into the building.

By the way, when storing wafers or the like in the clean stocker, there is a batch type transport / storage form using a cassette 1 whose inside is divided into a plurality of stages in the vertical direction by cassette pins 2 as shown in FIG. It has been adopted.
When the wafers 3 are stored in the clean stocker, first, in the previous process, a plurality of the wafers 3 carried out from the apparatus are stored between the cassette pins 2 of the cassette 1 to store the clean stocker. In addition, when the wafer is unloaded from the clean stocker, the wafers 3 and the like 3 are again taken out from the cassette 1 and transferred to an apparatus for a subsequent process.
JP 2003-249538 A JP-A-8-340043

  In such a batch-type transport / storage form using the cassette 1, a plurality of wafers 3 and the like 3 are stored in the same cassette 1 and are transported in a batch. 2 and the wafer 3 are in contact with each other at the portion A in the figure, and the wafer 3 is charged with static electricity.

In addition, every time it is stored in the clean stocker, it is necessary to store and take out the wafers 3 and the like from the cassette 1, and there is a problem that the process and apparatus become complicated.
For this reason, in recent years, in the transfer of these wafers and the like, there is an increasing demand for shifting from the batch method using the conventional cassette 1 to a so-called single wafer transfer method in which wafers or the like are transferred one by one.

  However, depending on the storage form using the stacker crane as in the above-described conventional clean stocker, the conveyance frequency is several tens of times higher than the case where the cassette 1 is used. There is a problem of requiring area and volume.

  The present invention has been made in view of such circumstances, and it is possible to store a plurality of wafers and other flat plate members with a minimum space for each one, and therefore it is easy to carry in and out the flat plate members. It is an object of the present invention to provide a single wafer stocker.

  In order to solve the above-mentioned problems, the invention described in claim 1 is arranged in upper and lower portions on both sides in the transport direction of the flat plate member in a casing provided with the flat plate member inlet and outlet. A rotation member provided, an endless member spanned between the rotation members, and a plurality of support members horizontally laid across the transfer direction at a plurality of positions between the endless members on both sides. At least two sets of support devices are installed at intervals so as to support both ends in the transfer direction of the flat plate member by the support members adjacent to each other in the transfer direction, and the rotating members of these support devices are reversed. By providing drive means for synchronously rotating in the direction, the flat plate member supported by the support member is raised and lowered.

  According to a second aspect of the present invention, in the lower part of the casing according to the first aspect, a roller that conveys while supporting both sides of the flat plate member from the carry-in port toward the carry-out port, and the flat plate A plate-like member conveying device provided in parallel with the roller on the back side of the plate-like member, and provided with a floating unit that floats the plate-like member by the jetting gas, and the endless member of the support device The support member is disposed between the rollers.

  Further, in the invention described in claim 3, the casing described in claim 2 is provided with a second casing that encloses the conveying device and the adjacent support member, and the second casing includes the second casing. A first clean dry air supply pipe filled with clean dry air (hereinafter referred to as ultra-low dew point air) having an atmospheric pressure dew point of −100 ° C. or less in which molecular contaminants have been removed to 10 ppb or less; The unit is provided with a second clean dry air supply pipe for supplying the clean dry air as a floating gas for the flat plate member.

  If the flat plate member is extremely disliked by molecular contaminants, it is more preferable to use the ultra low dew point air from which molecular contaminants of 5 ppb or less have been removed.

  Here, the ultra-low dew point air is provided with a plurality of disk-shaped members having high water absorption, such as silica gel, for example, and the plurality of stages of disk-shaped members are rotated from the blower while rotating the disk-shaped members. Passing through one section of the member, the dew point is lowered in sequence, and the disk-shaped member that has absorbed moisture is dried by a known ultra-low dew point air supply device in other sections in the rotational direction by a heater or the like. Obtainable.

  According to the above ultra-low dew point air supply device, contaminants such as organic matter contained in the air are also collected and removed when passing through a disk-shaped member such as silica gel arranged in a plurality of stages. However, by installing a predetermined ULPA filter in the final stage, it is possible to obtain clean ultra-low dew point air from which molecular contaminants have been removed to 10 ppb or less.

  According to the invention described in any one of claims 1 to 3, first, a flat plate member introduced into the inside from the carry-in port of the casing is passed between the support members of the support device, and both ends in the transport direction are set to 2 The pair of supporting devices are stopped by being positioned above the supporting members adjacent to each other in the transfer direction. Next, the above-mentioned supporting members are raised by synchronously rotating the rotating members in opposite directions by the driving means.

  Thereby, the both ends in the transport direction of the flat plate member are scooped up and raised by the support member. Next, another plate-like member introduced into the inside from the carry-in port of the casing is passed between the support members positioned below the support member, and the rotation member of the support device is reversed in the reverse direction by the driving means. By rotating synchronously, both end portions of the flat plate member are lifted and raised.

By repeating the above steps, a plurality of flat members can be stored one by one between a plurality of support members of adjacent support devices.
Further, when carrying out the flat plate member stored between the supporting devices, the above-described ascending process is repeated, and the upper flat plate member is sequentially discharged to the carry-out port of the casing using a pusher or the like, or By rotating the rotating member in the opposite direction to the above-described ascending process by the driving means to lower the supporting member, the rotating member can be sequentially sent from the lower flat plate member to the carry-out port of the casing.

  As a result, according to the single-wafer type stocker according to the present invention, it is possible to store a plurality of wafers and other flat plate-like members with a minimum space with simple equipment, and a conventional cassette. Compared with a batch-type transport / storage form using the above, the plate-like member can be carried in and out more easily.

  At this time, various forms of conveying means can be used as means for introducing the flat plate member into the casing from the carry-in port and for sending the flat plate member between the support members to the carry-out side. However, for example, a plate-like member conveying apparatus such as that described in claim 2 is preferably used. According to this transport device, the both ends of the flat plate member can be transported between the support members while being supported by the rollers, and the back surface side of the flat plate member is supported by the floating unit in a non-contact manner. It is also possible to prevent bending during conveyance while preventing the conveyance traces from being attached to the surface.

  Further, since the support member of the support device is disposed between the rollers, interference between the two can be prevented, and the support member is positioned below the roller, so that the support member can easily form a flat plate shape. It becomes possible to scoop and raise both ends of the member.

  Further, when the flat plate member is the wafer or the like, when moisture is adsorbed on the front and back surfaces during transportation and storage, the growth of a natural oxide film is promoted, or the metal or organic matter is dissolved therein. It can be a new source of contamination. In particular, it is also known that when a corrosive gas comes into contact with moisture on the surface in the process chamber, gas molecules dissolve into the moisture layer and become active ions to corrode the metal surface.

In addition, when contaminants such as fine organic substances contained in the compressed air adhere to the wafer or the like, when a metal film is formed in a subsequent process, insulation resistance cannot be obtained or the metal film is peeled off. May be incurred.
These adverse effects have become remarkable with the recent increase in size and size of the semiconductor wafer and flat display glass substrate.

  In this regard, according to the third aspect of the present invention, the second casing that encloses the transport device and the support member is provided, and the second casing is filled with the ultra-low dew point air, and in the levitation unit. Since the ultra-low dew point air is supplied as a levitation gas for the flat plate member, there is no possibility that contaminants such as moisture and organic matter which are harmful to the flat plate member are attached during transportation and storage. The production yield and quality of the flat plate member can be improved.

1 to 3 show an embodiment in which a single-wafer stocker according to the present invention is applied to a stocker for storing the wafer 3 or the like. Reference numeral 10 in the figure denotes an outer casing.
A carry-in port 11 and a carry-out port 12 are formed at both lower ends of the outer casing 10, and first support devices 13a and 13b and second support devices 14a and 14b are installed therein. Yes.

  The first support devices 13a and 13b are sequentially arranged in the transfer direction of the wafer 3 and the like, and a pair of sprockets (rotating members) 15a arranged opposite to the upper portions on both sides in the transfer direction. , 15b and a pair of sprockets (rotating members) 16a, 16b arranged opposite to each other, and between these upper and lower sprockets 15a, 16a and between the sprockets 15b, 16b, a chain (endless member) ) 17a and 17b are bridged.

  A large number of support rods (support members) 18a, 18b are installed horizontally between the chains 17a, 17b facing both sides in the transport direction at equal intervals over the entire circumference so as to cross the transfer direction. . Here, in the first support devices 13a and 13b, the distance between the support rods 18a and 18b adjacent to each other is somewhat shorter than the length dimension in the transfer direction of the assumed maximum length wafer 3 or the like. It is installed at intervals. And the 2nd support apparatus 14a, 14b is arrange | positioned so that each 1st support apparatus 13a, 13b may be enclosed.

  In these second support devices 14a and 14b, two sets of sprockets (rotating members) 19a to 19d are provided on both sides in the transport direction and above the sprockets 15a and 15b, respectively, so as to sandwich them. Are arranged opposite to each other. On the other hand, two sets of sprockets (rotating members) 20a to 20d are provided below the sprockets 16a and 16b and directly below the two sets of sprockets 19a to 19d, respectively.

  Then, chains (endless members) 21a (21b) between the upper and lower two sets of sprockets 19a (19b), 19c (19d), 20a (20b), and 20c (20d) in each second support device 14a (14b). ) Is wound. In addition, a large number of support rods (support members) 22a and 22b are installed horizontally between the chains 21a and 21b facing both sides in the transport direction at equal intervals over the entire circumference so as to cross the transfer direction. .

These second support devices 14a and 14b are such that the distance between the support rods 22a and 22b on the adjacent sides is somewhat shorter than the length dimension in the transfer direction of the assumed minimum length of the wafer 3 or the like. Are installed at intervals.
Further, a sensor for detecting the height of the support rods 18a, 18b, 22a, 22b in the first support devices 13a, 13b and the second support devices 14a, 14b at the height position of the transfer device described later (FIG. Not shown).

  The first support devices 13a, 13a and the second support devices 14a, 14b are linked to the sensors, respectively, and sprockets (15a, 16a), (15b, 16b), (19a, 19c, 20a, 20c), (19b, 19d, 20b, 20d) are provided with servo motors (drive means) (not shown) for synchronously driving the rotation.

  Here, the servo motor is controlled so that the first support devices 13a and 13a rotate the sprockets 15a and 16a and the sprockets 15b and 16b synchronously and in the opposite directions. Similarly, for the second support devices 14a and 14b, the servo motor rotates the sprockets 19a, 19c, 20a and 20c and the sprockets 19b, 19d, 20b and 20d synchronously and in the reverse direction. It is controlled.

  Further, in the outer casing 10, between the upper and lower sprockets 15a, 16a, 15b, 16b of the first support devices 13a, 13b, the support rods 18a, 18b adjacent to the first support devices 13a, 13b and An inner casing (second casing) 25 that includes only the supporting rods 22a and 22b adjacent to the second supporting devices 14a and 14b is provided. A slit 26 that allows the support rods 18a, 18b, 22a, and 22b to pass therethrough is formed on the side surface and the upper surface of the inner casing 25.

In addition, in the inner casing 25, an ultra-low dew point air supply pipe is filled with clean dry air (ultra low dew point air) having an atmospheric pressure dew point of −100 ° C. or less from which molecular contaminants are removed to 10 ppb or less. A first clean dry air supply pipe (not shown) is connected.
On the other hand, the lower part of the inner casing 25 is introduced into the carry-in port 11 from the device in the previous process and the like, and the device in the next process from the carry-out port 12 through the lower portions of the first and second support devices 13a, 13b, 14a, 14b. 3 is continuously provided.

  The transport device 30 includes a roller conveyor 32 that transports the wafer 3 and the like 3 to the carry-out port 12 side in a transport path casing 31 that is closed on the ceiling and both sides, and a guide for the roller conveyor 32. A floating unit 33 that supports the wafer 3 or the like 3 in a non-contact manner from the back surface side is provided at two locations with a predetermined interval between the attached conveying rollers 32a.

  Here, as shown in FIG. 3, each floating unit 33 has a porous ceramic plate 35 attached to the upper surface of a chamber 34 made of a metal casing having a rectangular shape in plan view, and the lower surface of the chamber 34 has the above-mentioned An ultra-low dew point air supply pipe (second clean dry air supply pipe) 36 is connected. A plurality of independent levitation units 33 are arranged so as to form two rows in parallel with the transport roller 32a.

  Furthermore, between the conveyance roller 32a and the levitation unit 33 and between the levitation units 33, each extends in the form of a strip in the conveyance direction to form the lower surface of the conveyance path casing 31 and float by ultra-low dew point air. A blocking member 37 for improving the effect is interposed. A motor that is a driving source of the roller conveyor 32 is provided outside the conveyance path casing 31.

  In the single wafer stocker having the above-described configuration, the inner casing 25 is continuously introduced by introducing the ultra-low dew point air into the inner casing 25 by the ultra-low dew point air supplied from the ultra-low dew point air supply pipe. In addition, the inside of the conveyance path casing 31 is held in an atmosphere of ultra-low dew point air. In this state, by forming an air film of 0.1 to 0.2 mm between the wafer 3 and the like by the ultra-low dew point air supplied from the ultra-low dew point air supply pipe 36 to the levitation unit 33, While supporting the wafer 3 or the like 3 from the back surface side in a non-contact manner, the wafer or the like 3 is carried into the inner casing 25 by the roller conveyor 32 from the apparatus or the like of the previous process.

  At this time, based on the detection signal from the height detection sensor, the servomotor is driven to rotate the sprockets 15a, 16a, 15b, 16b, 19a to d, and 20a to d, thereby supporting the support rods 18a, 22a is positioned somewhat below the upper surface of the conveying roller 32a of the conveying device 30.

  Next, when both ends of the wafer 3 or the like in the conveyance direction are positioned on the adjacent support bars 18a and 18b of the first support devices 13a and 13b, the conveyance by the roller conveyor 32 is stopped and the servo motor is operated. The sprockets 15a, 16a, 15b, 16b, 19a to d and 20a to d are rotated synchronously so that the moving speeds of the support rods 18a, 18b, 22a and 22b are constant.

  At this time, for the first and second support devices 13a, 14a on the left in FIG. 1, the sprockets 15a, 16a, 19a, 19c, 20a, 20c are rotated counterclockwise, For the first and second support devices 13b and 14b, the sprockets 15b, 16b, 19b, 19d, 20b, and 20d are rotated in the clockwise direction. Then, the wafer 3 is lifted up from the back side by the total of four support rods 18a, 18b, 22a, and 22b and then lifted.

Next, after raising one pitch of the support rods 18a, 18b, 22a, 22b in the vertical direction, the servo motor is once stopped and the roller conveyor 32 is operated, and the lower support rods 18a, 18b, The next wafer 3 or the like is positioned between 22a and 22b.
Then, by repeating the above steps, a plurality of wafers 3 and the like 3 are stored and supported one by one between the support rods 18a, 18b, 22a, and 22b upward in the inner casing 25.

  Thus, when unloading the wafer 3 or the like stored in the single wafer stocker, the servo motor causes the sprocket to move in the direction opposite to the above-described ascending step, that is, the first and the left in FIG. As for the second support devices 13a and 14a, the sprockets 15a, 16a, 19a, 19c, 20a and 20c are rotated in the clockwise direction, and the first and second support devices 13b and 14b on the right side in FIG. The sprockets 15b, 16b, 19b, 19d, 20b, and 20d are rotated counterclockwise.

  As a result, the support bars 18a, 18b, 22a, 22b supporting the wafer 3 are lowered. Therefore, by sequentially repeating the placement of the lowermost wafer 3 or the like 3 on the transfer roller 32a of the transfer apparatus 30 and the transfer to the carry-out port 12 side, a plurality of sheets stored in the single wafer stocker are stored. The wafer 3 or the like 3 can be transferred to a subsequent process apparatus or the like by the transfer device 25.

  Thus, according to the single wafer stocker, a plurality of wafers 3 and the like 3 can be stored in a minimum space for each piece with simple equipment, and a batch type using a conventional cassette. Compared with the transfer / storage mode, it becomes easier to carry in and out the wafer 3 and the like.

  In addition, the outer casing 10 is provided with an inner casing 25 that includes a portion to be engaged with the transfer device 30 and support rods 18a, 18b, 22a, and 22b that support the wafer 3 and the like adjacent thereto. The casing 25 is filled with ultra-low dew point air, and the above-mentioned ultra-low dew point air is supplied as a floating gas for the wafer 3 etc. in the levitation unit 33, which is harmful to the wafer etc. 3 during transportation and storage. Therefore, there is no risk of adhering contaminants such as moisture and organic matter, so that the production yield and quality of the wafer 3 can be improved.

In the above embodiment, the present invention has been described only when applied to a single wafer stocker used for storing wafers 3 and the like. However, the present invention is not limited to this. It is possible to apply to storage of a flat member.
Moreover, although the case where the chain 17a, 17b, 21a, 21b was spanned over the sprocket as an endless member was described, it replaces with the said chain and a wire, a belt, etc. can also be used.

  Further, in the above embodiment, when the carry-in port 11 and the carry-out port 12 are provided in the lower part of the casing and the wafer 3 or the like once stored is taken out, the above-described lifting process of the sprocket is reversed by the servo motor. The support rods 18a, 18b, 22a, and 22b are moved downward in order to be sequentially sent from the lower wafers 3 to the carry-out port. However, the present invention is not limited to this. In addition to providing the carry-out port 12 at the top, when carrying out the wafer 3 stored between the support rods, the above-described ascending process is repeated to sequentially carry out the carry-out port from the upper wafer etc. 3 using a pusher or the like. It is also possible to pay out to 12.

It is a longitudinal cross-sectional view which shows one Embodiment of the single wafer type stocker concerning this invention. It is a top view of FIG. It is a cross-sectional view of the conveying apparatus of FIG. It is a front view which shows the cassette currently used for conveyance of the conventional wafer etc.

Explanation of symbols

10 Outer casing (casing)
11 carry-in port 12 carry-out port 13a, 13b first support device 14a, 14b second support device 15a, 15b, 16a, 16b, 19a, 19b, 19c, 19d, 20a, 20b, 20c, 20d sprocket (rotating member)
17a, 17b, 21a, 21b Chain (endless member)
18a, 18b, 22a, 22b Support rod (support member)
25 Inner casing (second casing)
30 Conveying Device 32 Roller Conveyor 32a Conveying Roller 33 Floating Unit 36 Ultra Low Dew Point Air Supply Pipe (Second Clean Dry Air Supply Pipe)

Claims (3)

  Rotating members respectively disposed on the upper and lower sides on both sides of the plate-shaped member in the transfer direction in the casing provided with the plate-like member carrying-in port and carrying-out port, and endlessly spanned between these rotating members At least two sets of support devices each including a member and a plurality of support members laid horizontally so as to cross the transfer direction at a plurality of locations between the endless members on both sides are adjacent to each other in the transfer direction. The supporting member is supported by the supporting member by providing a driving means for rotating the rotating member of the supporting device in the reverse direction by installing the supporting member at intervals so as to support both ends in the transport direction of the flat plate member. A single wafer stocker characterized in that the flat plate-like member is moved up and down.   In the lower part of the casing, a roller that conveys while supporting both sides of the flat plate member from the carry-in port toward the carry-out port, and a roller arranged in parallel with the back surface side of the flat plate member, A flat plate member conveying device including a floating unit that levitates the flat plate member with a jetting gas is provided, and the endless member and the support member of the support device are disposed between the rollers. The single wafer stocker according to claim 1.   The casing is provided with a second casing that encloses the transport device and the adjacent support member, and the second casing has an atmospheric pressure in which molecular contaminants are removed to 10 ppb or less. A first clean dry air supply pipe to be filled with clean dry air having a dew point of −100 ° C. or less; a second clean dry air supply pipe for supplying the clean dry air to the floating unit as a floating gas for the flat plate member; The single-wafer type stocker according to claim 2, wherein:

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