JPH08148543A - Substrate pad, and substrate drawing out/containing device and substrate transfer device with it - Google Patents

Abstract

PURPOSE: To provide a substrate drawing out/containing device and a substrate transfer device which ensure drawing out operation of a substrate from a cassette by preventing the cassette from rising and a substrate pad to be used for each device. CONSTITUTION: Receiving grooves 40d, 40e, etc., for receiving a substrate provided parallel to a substrate pad 40 which is made to pass through in a cassette and thereby draws out a substrate from a cassette are divided into a plurality of division parts 41 to 45 in a substrate alignment direction and is formed to have a step between division parts mutually. Thereby, the number of substrates to be raised simultaneously is reduced and friction force generated between a substrate and a cassette is also relaxed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer operation for extracting a substrate such as a silicon wafer or a liquid crystal glass substrate housed in a cassette in a line and transferring it to another cassette. Regarding the device. Also,
The present invention relates to a substrate extraction / accommodation device that is installed in the substrate transfer device or the like to perform the operation of extracting and accommodating a substrate from a cassette, and the substrate transfer device and the substrate extraction / accommodation device for extracting and accommodating the substrate from the cassette And a substrate pedestal to be used in the device.

[0002]

2. Description of the Related Art Conventionally, a substrate transfer device of this type is shown in FIG.

As shown in the figure, this conventional substrate transfer apparatus is provided with a pair of first traverse bases 2 of substantially the same shape which are horizontally arranged in parallel with each other, and are arranged in parallel with each traverse base 2. And a second traverse stand 3 disposed below the base. The first traverse base 2 and the second traverse base 3 are mutually connected and integrated,
This combined body is collectively referred to as the movable base 5. 10 and 11 show the planar shapes of the first traverse base 2 and the second traverse base 3. The movable base 5 is
It is driven by a base driving means (not shown) to move forward and backward (indicated by an arrow F), and is appropriately positioned at a position indicated by a chain double-dashed line and a solid line in the figure.

As shown in FIG. 9, one first cassette 7 is mounted on each first traverse table 2,
Two second cassettes 8 are mounted on the second traverse table 3. More specifically, as shown in FIG. 10, the first traverse base 2 is formed with an opening 2a that opens at one end side in the moving direction thereof, and the first cassette 7
Is placed so that the bottom portion corresponds to the opening 2a.
Further, as shown in FIG. 11, the second traverse table 3 has two openings 3a opened at one end side in the moving direction and another two openings 3b opened at the other end side.
Are formed, and the second cassette 8 is placed so that the bottom portion corresponds to the opening portion 3a on the one end side.
Further, the opening 3b on the other end side is formed so as to vertically match the opening 2a provided on the first traverse base 2. In FIG. 9, reference numeral 2
Shown by b is the first traverse table 2 on the first traverse base 2.
Is a positioning piece that engages with the lower end of the cassette 7 to position the cassette 7. Although not shown, a similar positioning piece is provided on the second traverse table 3 to position the second cassette 8.

The first cassette 7 and the second cassette 8 will be described.

The first cassette 7 and the second cassette 8 include a plurality of, for example, 25 silicon wafers 10.
That is, the substrates can be accommodated in an array at equal intervals so that their principal surfaces are parallel to each other. The first cassette 7 is provided for cleaning the contained silicon wafer 10. Here, the situation when the silicon wafer 10 is cleaned using the first cassette 7 will be briefly described with reference to FIG.

FIG. 12 shows an outline of a cleaning processing apparatus for automatically cleaning the silicon wafer 10. As shown in the figure, the cleaning processing apparatus includes, for example, three processing tanks 11 to 13. The pre-cleaning processing liquid 11a is stored in the processing tank 11, and the etching processing liquid 12a is stored in each of the other processing tanks 12 and 13 subsequent thereto.
And the post-cleaning treatment liquid 13a is stored. However, the number of processing tanks equipped and the type of processing liquid stored in each of them are appropriately set according to the processing content.

Further, the cleaning processing apparatus is provided with a transfer means (not shown), and the first cassette 7 is transferred by the transfer means, and the processing liquid stored in each of the processing tanks 11 to 13 in the process of the transfer. Then, each silicon wafer 10 contained in the cassette 7 is washed.

As described above, since the first cassette 7 is immersed in various processing liquids together with the silicon wafer 10 accommodated therein, it is formed of a necessary material such as Teflon in order to avoid corrosion due to the processing liquids. There is.

On the other hand, the second cassette 8 is for transporting the silicon wafer 10 which has been cleaned as described above to the subsequent step, and like the first cassette 7, the corrosion resistance and the like are taken into consideration. It is not necessary and is molded from a relatively inexpensive general material.

The shapes of the first cassette 7 and the second cassette 8 are as follows. However, in this case, the first cassette 7 and the second cassette 8 are made of different materials,
The shapes of the first cassette 7 are the same as each other, so the shape of the first cassette 7 will be described.

As shown in FIGS. 13 and 14, the first cassette 7 is open at the top for loading and unloading the silicon wafers 10, and the inner wall is engaged with the outer peripheral portion of each silicon wafer 10. Support grooves 7a are arranged in parallel.
By engaging the support grooves 7a, the silicon wafers 10 are aligned and held so that their principal surfaces are parallel to each other. An overhanging portion 7b is formed on the upper end of the first cassette 7 so as to face outward. The transporting means included in the above-described cleaning processing device suspends and transports the cassette 7 at the projecting portion 7b.

An opening 7c is formed at the bottom of the first cassette 7. The opening 7c discharges the processing liquid that has entered the cassette 7 during the cleaning process described above, and also transfers the silicon wafer 10 from the first cassette 7 to the second cassette 8 as described later. At this time, the substrate pedestal (described later) passes through.

As shown in FIG. 9, the first cassette 7 is used.
The second cassette 8 and the second cassette 8 are mounted so that the respective bottom openings thereof correspond to the openings 2a and 3a formed in the first traverse table 2 and the second traverse table 3, respectively.

As shown in FIG. 9, the openings 2a, 3a of the first traverse base 2 and the second traverse base 3 are formed.
A pair of substrate pedestals 15 are arranged at predetermined positions corresponding to 3b. These substrate pedestals 15 are provided with the openings 2a,
The cassettes 3a, 3b and the first and second cassettes 7 and 8 can be inserted into the both cassettes through the bottom openings thereof, and can receive the silicon wafers 10 in the respective cassettes in an aligned state. More specifically, as shown in FIG. 15, the substrate pedestal 15 is formed in a substantially rectangular plate shape as a whole, and three longitudinal projections 15a, 15b and 15c are formed in parallel along the longitudinal direction thereof. Has been done. The projections 15a to 15c are provided with receiving grooves 15d, 15e, and 15f, which can be engaged with the outer peripheral portion of each silicon wafer 10, in parallel over the entire length. As a result, the silicon wafers 10 are aligned and supported so that their principal surfaces are parallel to each other. As is clear from FIG. 15, the receiving grooves 15d, 15e and 15f are
Its cross-sectional shape is substantially Y-shaped.

The substrate pedestals 15 are carried by pedestal driving means (not shown) and driven to move up and down.
Thereby, the first cassette 7 and the second cassette 8
Is inserted into and removed from. The pedestal driving means and the substrate pedestal 15 pull out the silicon wafer 10 from the first cassette 7 and the second cassette 8
A substrate extraction / accommodation device for performing the accommodating work is configured.

As shown in FIG. 9, above the substrate extracting / accommodating device, the silicon wafers 10 are once received from the ascending substrate receiving bases 15 and are transferred in reverse, that is, the transfer is performed. Delivery means 18 is provided. As shown in the figure, the delivery means 18 includes two shafts 19 that are rotatably provided, and each of the shafts 19.
A drive means 20 for relatively rotating the arm and an arm member 2 attached to the tip of each shaft 19 in a suspended state.
1, a total of four support shafts 22 connected to the free ends of the arm members 21, two at one end, and extending horizontally in parallel with each other, and supporting the other end of each support shaft 22. At the same time, it has a guide member 24 for smoothly guiding it in the direction in which it should operate. Each of the support shafts 22 includes
Support grooves (not denoted by reference numerals) that engage with the outer peripheral portion of the silicon wafer 10 are arranged in parallel along the longitudinal direction, for example, 50 rows, and 50 silicon wafers, that is, two silicon wafers 10 for a cassette are aligned. Maintain and support the state.

Next, the operation of the substrate transfer device having the above structure will be described. The following operations are controlled by a control unit including a microcomputer or the like included in the substrate transfer apparatus.

In FIG. 9, two first cassettes 7 containing the cleaned silicon wafers 10 are placed on the first traverse table 2, respectively. Also, two empty second cassettes 8 are placed on the second draft stand 3. Then, the movable base 5 composed of the first traverse base 2 and the second traverse base 3 is moved forward from the position indicated by the chain double-dashed line by the operation of the base driving means (not shown) to reach the position indicated by the solid line. . As a result, the two first cassettes 7 are positioned at a predetermined position, that is, immediately above each substrate pedestal 15.

In this state, the pedestal driving means (not shown) is activated to raise both substrate pedestals 15. Both board pedestal 1
5 is a second traverse stand 3 and a first traverse stand 2
Through the openings 3b and 2a formed in the first cassette 7, the first cassette 7 is inserted through the bottom opening. Therefore, each silicon wafer 10 in the first cassette 7 is supported by the substrate pedestal 15 and extracted upward.
At this time, with respect to the delivery means 18 disposed above, both arm members 21 included in the delivery means 18 are rotated in the mutually separated directions, and two support shafts 22 each of which should support the silicon wafer 10 are provided. It is open.

The above-mentioned two substrate pedestals 15 are further raised together with the supported silicon wafers 10, reach the maximum raised position, and are stopped. In this state, the silicon wafers 10 are located between the support shafts 22. Then, the delivery means 18 is operated and the respective support shafts 22 are closed, that is, chucked. When this chucking operation is completed, both of the substrate supporters 15 are lowered. As a result, each silicon wafer 10 engages with the support groove formed in each support shaft 22 and is received by each support shaft 22.

When both of the descending substrate receiving bases 15 pass through the first cassette 7, the first traverse base 2 and the third traverse base 3 and reach the lowest position, the movable base 5 is moved back. 9 reaches the position shown by the chain double-dashed line in FIG. As a result, the first cassette 7 is detached from directly above the substrate pedestal 15, and the second cassette 8 is positioned directly above the substrate pedestal 15 instead.

After that, both of the above-mentioned board supports 15 are raised again. Therefore, the substrate pedestal 15 passes through the opening 3a of the second traverse table 3 and the second cassette 8 to reach the highest position. As a result, the silicon wafers 10 supported by the support shafts 22 of the transfer means 18 are slightly lifted by the substrate pedestals 15 and passed to the substrate pedestals 15. Then, each support shaft 22 is opened, that is, counter-chucked.

When this anti-chucking operation is completed, both substrate pedestals 15 are lowered together with each silicon wafer 10 held by them. Therefore, each of the silicon wafers 10 is stored in the second cassette 8 and only the two substrate holders 15 further descend to reach the lowest position.

[0025]

The substrate transfer device having the above-mentioned structure has the following problems.

As described above, the first cassette 7 is formed with the support groove 7a, and the silicon wafers 10 are brought into alignment by engaging the support groove 7a at the outer peripheral portion thereof. The support groove 7a is provided for the purpose of facilitating the entry of the silicon wafer 10 into the support groove 7a and improving the cleaning efficiency of the cleaning processing apparatus shown in FIG.
It is set to be slightly larger than the thickness dimension of 0. Therefore, as shown in FIG. 16, the silicon wafer 10 can be tilted within the groove width of the support groove 7a.

In this case, the above-mentioned substrate pedestal 15 is the first
The following events may occur when holding each silicon wafer 10 inserted through the bottom opening of the cassette 7.

That is, as shown in FIG. 15, a large number of receiving grooves 15d, 15e, 15f are formed in the substrate pedestal 15, and these receiving grooves are formed in the silicon wafer 10 as the substrate pedestal 15 moves up. The silicon wafer 10 is brought into a state of being engaged with the outer peripheral portion on the lower end side and lifting the silicon wafer 10. At this time, as shown in FIG. 17, the receiving groove 15e is formed on the lower end portion of the silicon wafer 10 (the other receiving grooves 15d and 15f are not shown, but the same phenomenon occurs).
The corner portion 15g or the inclined surface portion 15h having a Y-shaped cross section is engaged. However, in detail, the corner portion 15g is engaged with the chamfered portion 10a of the silicon wafer 10. Therefore, as shown in FIG. 16, the silicon wafer 10 has its own weight W and the inclined surface portion 15h or the chamfered portion 10a.
Since the lower end portion receives a component force Wh in the substantially horizontal direction based on the inclination angle of the upper wall portion 10b, which is in substantially point contact with the inner wall surface of the support groove 7a of the first cassette 7, the upper wall portion 10b is against the inner wall surface. It is pressed with this component force Wh. Further, since the silicon wafer 10 inclines itself in the support groove 7a, a pressing force P based on its own weight W and its inclination angle is exerted on the inner wall surface of the support groove 7a at the upper portion 10b. . Regarding the component force Wh and the pressing force P, in this case, the three receiving grooves 15 provided in the substrate pedestal 15 for receiving one silicon wafer 10 in cooperation with each other.
The values generated for d, 15e, and 15f are combined values.

Therefore, if the coefficient of friction between the silicon wafer 10 and the inner wall surface of the support groove 7a in contact with the silicon wafer 10 is μ, then when the silicon wafer 10 is lifted by the substrate pedestal 15, A frictional force μ (Wh + P) is generated between them. This frictional force acts as a force for lifting the first cassette 7 as the silicon wafer 10 is lifted. Although the frictional force generated in one silicon wafer 10 is relatively small, the substrate pedestal 15 lifts, for example, 25 silicon wafers 10 contained in the first cassette 7 at the same time. As a result, the frictional force will be quite large.

On the other hand, in addition to the above causes, frictional force is also generated due to the following causes.

That is, the supporting groove 7a formed in the first cassette 7 and the receiving grooves 15d of the substrate receiving table 15
The pitches of 15e and 15f are set to be equal to each other, and in the device shown in FIG. 9, the first groove is formed so that the support groove 7a and the receiving grooves 15d to 15f coincide with each other.
The cassette 7 is positioned with respect to the substrate pedestal 15 with high accuracy. However, the substrate pedestal 15 that is kept at room temperature
On the other hand, since the first cassette 7 is exposed to the temperature change by being immersed in the processing liquid, the pitch of the support groove 7a and the receiving grooves 15d to 15f are not aligned as shown in FIG. there is a possibility.

When such a deviation occurs, as shown in the drawing, when the respective receiving grooves 15d to 15f of the substrate pedestal 15 are engaged with the silicon wafer 10, the silicon wafer 1
0 is slightly elastically deformed into a bow, and as a result, as shown in FIG. 18, the support groove 7 of the first cassette 7 is
Silicon wafer 1 in contact with the inner wall surface of a at two points
The upper part 10b of 0 has a pressing force Q /
2 will be exerted on the inner wall surface. Therefore, when the silicon wafer 10 is lifted by the substrate pedestal 15, a frictional force μQ is generated between the silicon wafer 10 and the inner wall surface of the support groove 7a. This frictional force also acts to lift the first cassette 7, and is similarly generated in each silicon wafer 10 containing 25 sheets,
The overall power is quite large.

As described above, the substrate pedestal 15 allows the first
When a frictional force is generated between each silicon wafer 10 and the cassette 7 when the silicon wafer 10 is removed from the cassette 7, the cassette 7 is relatively lightweight and the friction against its own weight. If the strength is overcome, the first cassette 7 itself may float up from the first traverse table 2. As a result, the substrate transfer device becomes inoperable.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and is used in a substrate unloading / accommodating device and a substrate transfer device for reliably performing a substrate unloading operation from a cassette, and the respective devices. The object is to provide a substrate pedestal to be used.

[0035]

In order to achieve the above object, a substrate pedestal according to the present invention is provided with receiving grooves arranged in parallel with each other so that the outer peripheral portions of the substrates can be engaged with each other so that the main surfaces of the substrates are substantially parallel to each other. Each of the receiving grooves is divided into a plurality of divisions in the substrate alignment direction, and each of the divisions is formed with a step between them. In addition, the substrate extracting and accommodating apparatus according to the present invention allows the substrates to be aligned and held so that their main surfaces are substantially parallel to each other, and can be inserted through the bottom opening of the cassette and the substrates can be aligned. A substrate pedestal that receives the substrate while maintaining the state, and a pedestal drive means that carries the substrate pedestal and moves it so as to insert into and remove from the cassette, and the outer peripheral portion of the substrate is engaged with the substrate pedestal. Receiving grooves that can be fitted are arranged in parallel, each receiving groove is divided into a plurality of dividing portions in the substrate alignment direction, and the dividing portions are formed with a step therebetween. Also,
A substrate transfer apparatus according to the present invention includes a movable base that mounts a first cassette and a second cassette on different portions, each of which is capable of holding a substrate in an array such that its principal surfaces are substantially parallel to each other, and a movable base. Base driving means for moving the movable base so as to position the first cassette and the second cassette at predetermined positions; and the cassette for each of the first cassette and the second cassette provided at the predetermined position. A substrate pedestal that can be inserted through the bottom opening and receives each of the substrates in an aligned state, and a substrate pedestal that carries the substrates and moves to insert and remove the first cassette and the second cassette. A pedestal driving means, and a delivery means for delivering the substrate to the substrate pedestal,
Receiving grooves that can be engaged with the outer peripheral portion of the substrate are arranged in parallel on the substrate pedestal, and each of the receiving grooves is divided into a plurality of dividing portions in the substrate alignment direction, and the dividing portions are stepped from each other. It is formed by.

[0036]

In such a structure, when the substrate holder is inserted into the cassette so as to receive the substrate, the receiving groove for each of the dividing portions engages with the substrate in the order of the step from the higher step. .

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A substrate transfer apparatus as an embodiment of the present invention will be described below with reference to the accompanying drawings. The substrate transfer apparatus is configured in the same manner as the conventional substrate transfer apparatus described with reference to FIGS. 9 to 18 except for the portions described below, and therefore the description of the entire apparatus is omitted. Only explain. Further, in the following description, the same reference numerals are used for the same components as those of the conventional substrate transfer apparatus, and for silicon wafers and cassettes (second cassettes) as substrates to be handled.

As shown in FIG. 1, in the substrate transfer apparatus, a first cassette 31 which is a small-sized and low-height self-standing cassette is used, which is mounted on the first traverser table 2. The first cassette 31
Is used for cleaning processing by the cleaning processing apparatus shown in FIG.

As shown in FIG. 2, the first cassette 3
Reference numeral 1 denotes a total of four longitudinal substrate supporting members 32 provided in parallel so as to correspond to two on the lower left and right sides of the silicon wafer 10 to be held, and interposed between the end portions of the respective substrate supporting members 32. And a pair of flat plate-shaped side members 36 for connecting the ends to each other.

As shown in FIG. 3, each of the substrate supporting members 3 is
2 has a substantially cylindrical shape as a whole, and support grooves 32a that engage with the outer peripheral portion of the silicon wafer 10 are arranged in parallel in the longitudinal direction at equal pitches. As shown in the figure, the support groove 32a has a substantially trapezoidal cross section, and in this embodiment, 26 rows are formed. Therefore, 26 silicon wafers 10 can be held, and each silicon wafer 10 can be held.
By being engaged with the support groove 32a, are aligned and held so that their principal surfaces are parallel to each other. Note that the second cassette 8 shown in FIG.
It is possible to accommodate six silicon wafers 10.

In FIG. 1, the substrate pedestal 40 provided for removing the silicon wafer 10 from the first cassette 31 and accommodating the silicon wafer 10 in the second cassette 8 is as follows. Is formed in.

As shown in FIGS. 2 and 4, the substrate pedestal 40
Is formed in a flat rectangular parallelepiped shape as a whole, and three longitudinal projections 40a, 40b are arranged in parallel along the longitudinal direction.
And 40c are formed. And these protrusions 40
In each of a to 40c, receiving grooves 40d, 40e and 40f with which the outer peripheral portion of each silicon wafer 10 can engage are arranged side by side in 26 rows. As a result, the silicon wafers 10 are aligned and supported so that their principal surfaces are parallel to each other. In addition, each of these receiving grooves 40d to 4
0f has a substantially Y-shaped cross section.

As is apparent from FIG. 5, the receiving groove 40 is formed.
Each of d, 40e, and 40f is divided into a plurality of, in this case, five division parts 41 to 45 in the silicon wafer alignment direction (substrate alignment direction). Since FIG. 5 is a longitudinal sectional view, the receiving groove 40f on one side of the substrate pedestal 40 is not shown, but the receiving groove 40f is on the other side.
And the shape is symmetrical.

Each of the dividing portions 41 to 45, except for the central dividing portion 43, has each of the receiving grooves 40d, 40e, 4 described above.
5 of each 0f are included, and the central dividing portion 43
6 includes each of the receiving grooves. And
As is clear from the figure, each of the receiving grooves 40d, 40e, 40
f is formed so as to have a step between each of the division parts 41 to 45. Specifically, in the present embodiment, it is set so that it gradually lowers from the dividing section 41 toward the dividing section 45. However, in each of the division parts 41 to 45, there are five or six receiving grooves 40d, 4 included therein.
0e and 40f are formed with the same level.

Next, the operation of the substrate transfer device having the above structure will be described. First, the operation of the entire apparatus will be briefly described.

In FIG. 1, two first cassettes 31 each containing 26 cleaned silicon wafers 10 are placed on the first traverse table 2. Also, two empty second cassettes 8 are placed on the second traverse table 3. Then, the movable base 5 composed of the first traverse base 2 and the second traverse base 3 is moved forward from the position indicated by the chain double-dashed line by the operation of the base driving means (not shown) to reach the position indicated by the solid line. . As a result, the two first cassettes 31 are positioned at predetermined positions, that is, directly above the substrate pedestals 40.

In this state, the pedestal driving means (not shown) is activated to raise both substrate pedestals 40. Both board support 4
0 is the second traverse table 3 and the first traverse table 2
Through the openings 3b and 2a formed in the first cassette 31, the first cassette 31 is inserted through the bottom opening. Therefore, each silicon wafer 10 held by the first cassette 31 is supported by the substrate pedestal 40 and extracted upward. At this time, with respect to the delivery means 18 disposed above, both arm members 21 provided therein are rotated in the mutually separating direction, and two support shafts 22 each of which should support the silicon wafer 10 are provided. It is open.

Both of the above-mentioned substrate pedestals 40 are further raised together with the supported silicon wafers 10, reach the maximum raised position, and are stopped. In this state, the silicon wafers 10 are located between the support shafts 22. Then, the delivery means 18 is operated and the respective support shafts 22 are closed, that is, chucked. When this chucking operation is completed, both of the substrate supporters 40 are lowered. As a result, the silicon wafers 10 engage with the support grooves formed in the support shafts 22 and are received by the support shafts 22 in an aligned state. The support groove is formed with 52 threads.

The first and the second board pedestals 40 that descend are emptied
When it reaches the lowest position after passing through the cassette 31, the first traverser base 2 and the third traverser base 3, the movable base 25 is moved back to reach the position shown by the chain double-dashed line in FIG. As a result, the first cassette 31 is horizontally detached from directly above the substrate pedestal 40, and the second cassette 8 is positioned directly above the substrate pedestal 40 instead.

After that, both of the substrate supporters 40 are raised again. Therefore, the substrate pedestal 40 passes through the opening 3a of the second traverse table 3 and the second cassette 8 to reach the highest position. Thereby, each silicon wafer 1 supported by each support shaft 22 of the delivery means 18
0 is in a state of being slightly lifted by each substrate pedestal 40 and passed to each substrate pedestal 40. Then, each support shaft 22 is opened, that is, counter-chucked.

When this anti-chucking operation is completed, both substrate pedestals 40 are lowered together with the held silicon wafers 10. Therefore, each of the silicon wafers 10 is stored in the second cassette 8 and only the two substrate holders 40 further descend to reach the lowest position.

Next, the operation when the respective silicon wafers 10 in the first cassette 31 are extracted upward by the substrate support 40 will be described in detail.

As described above, the receiving grooves 40d, 40e, 40f arranged in parallel on the substrate pedestal 40 are divided into five dividing portions 41 to 45 in the alignment direction of the silicon wafer, and between the dividing portions. Are formed with steps. Therefore, when the substrate pedestal 40 is inserted into the first cassette 31 from below to receive the respective silicon wafers 10, the receiving grooves 40d, 40e, 40f of each of the dividing portions 41 to 45 become high. The silicon wafers 10 are engaged with each other in the order from the step to the step. That is, in the substrate pedestal 40 of the present embodiment, the division section 41
To the partitioning portion 45 in order, they are engaged in this order. Therefore, as described below, the first cassette 3
In the case where a frictional force is generated between each silicon wafer 10 and the cassette 31 due to various causes such as the inclination of the silicon wafer 10 in the cassette 1, all of the 26 silicon wafers 10 accommodated in the cassette 31 The frictional force does not act at the same time, and the above-mentioned division parts 4
A relatively small frictional force generated on the silicon wafer 10 every 1 to 45 acts sequentially with a time difference. Therefore, even if the first cassette 31 is small and lightweight as in the present embodiment, it does not float up due to the frictional force, and the work of extracting the silicon wafer 10 by the substrate pedestal 40 is surely performed.

Here, the frictional force generated between the silicon wafer 10 and the first cassette 31 will be described.

As described above, the first cassette 31 has four
It has a substrate support member 32 of a book, and each substrate support member 32 is formed with a support groove 32a. The outer peripheral portions of the respective silicon wafers 10 are brought into alignment by engaging with the support grooves 32a. The support groove 32a is
The thickness of the silicon wafer 10 is set to be slightly larger than the thickness of the silicon wafer 10 for the purpose of facilitating the smooth entry of the silicon wafer 10 into the support groove 32a and enhancing the efficiency of cleaning by the cleaning apparatus shown in FIG. Has been done. Therefore, as shown in FIG. 6, the silicon wafer 10 can be tilted within the groove width of the support groove 32a.

When the silicon wafer 10 is tilted in this way, the above-mentioned substrate pedestal 40 is used for the first cassette 3 described above.
The following events may occur when holding each silicon wafer 10 inserted through the bottom opening of No. 1.

That is, as described above, the substrate pedestal 40
A large number of receiving grooves 40d, 40e, 40f are formed on the substrate 10. When the substrate pedestal 40 is raised, these receiving grooves engage with the outer peripheral portion of the lower end side of the silicon wafer 10 to lift the silicon wafer 10. It becomes a state. At this time, as shown in FIG. 7, the receiving groove 40e (other receiving grooves 40d and 4d) is formed on the lower end portion of the silicon wafer 10.
Y is not shown for 0f but causes similar events)
The corner portion 40g or the inclined surface portion 40h having a V-shaped cross section is engaged. However, more specifically, the corner portion 40g is engaged with the chamfered portion 10a of the silicon wafer 10. Therefore, as shown in FIG. 6, the silicon wafer 10 receives at its lower end a substantially horizontal component force Wh based on its own weight W and the inclination angle of the inclined surface portion 40h or the chamfered portion 10a. The upper portion 10b, which is substantially in point contact with the inner wall surface of the support groove 32a of the substrate support members 32 provided above the one substrate 31 of the first cassette 31, presses against the inner wall surface with this component force Wh. To be done. Further, since the silicon wafer 10 inclines itself within the support groove 32a, a pressing force P based on its own weight W and its inclination angle is exerted on the inner wall surface of the support groove 32a at the upper portion 10b. Become. Regarding the component force Wh and the pressing force P, in this case, each of the three receiving grooves 40d, 40e and 40f provided in the substrate pedestal 40 to receive one silicon wafer 10 in cooperation with each other. The values that occur with respect to are combined values.

Therefore, if the coefficient of friction between the silicon wafer 10 and the inner wall surface of the support groove 32a with which the silicon wafer 10 is in contact is μ, then when the silicon wafer 10 is lifted by the substrate pedestal 40, A frictional force μ (Wh + P) is generated between them. This frictional force acts as a force for lifting the first cassette 31 as the silicon wafer 10 is lifted. The frictional force generated in one silicon wafer 10 is relatively small, but if the number of silicon wafers 10 that are simultaneously lifted is large, the total frictional force becomes large, and if this exceeds the weight of the first cassette 31. The cassette 31 will be lifted. In the substrate transfer apparatus, as described above, the total number of silicon wafers 10 that can be simultaneously lifted by the substrate pedestal 40 is limited to 5 and 6 so that the total frictional force can be kept small.

On the other hand, in addition to the above causes, frictional force is also generated by the following causes.

That is, the support groove 32a formed in the first cassette 31 and each receiving groove 40 of the substrate pedestal 40.
The pitches of d, 40e and 40f are set to be equal to each other, and in the device shown in FIG. 1, the support groove 32a and the receiving grooves 40d to 40f are aligned with each other.
The first cassette 31 is positioned with high accuracy with respect to the substrate pedestal 40. However, since the first cassette 31 is exposed to the temperature change with respect to the substrate pedestal 40 kept at room temperature by being immersed in the processing liquid, as shown in FIG. 8, the supporting groove 32a and each receiving groove 40d are formed. There is a possibility that the pitches of 40 f to 40 f are not aligned and a deviation occurs.

When such a deviation occurs, as shown in the drawing, when the respective receiving grooves 40d to 40f of the substrate pedestal 40 are engaged with the silicon wafer 10, the silicon wafer 1
0 is slightly elastically deformed in a bow shape, and as a result, as shown in FIG.
Upper part 1 of the silicon wafer 10 which is in contact at a point
0b exerts a pressing force Q / 2 based on this elastic deformation on the inner wall surface. Therefore, when the silicon wafer 10 is lifted by the substrate pedestal 40, a frictional force μQ is generated between the silicon wafer 10 and the inner wall surface of the support groove 32a, and this frictional force also causes the first cassette 31 to float. It will be the power to This frictional force is also small for one silicon wafer 10, but the total frictional force becomes large when the number of silicon wafers that can be lifted at one time is large. As described above, in the substrate transfer apparatus, since the number of silicon wafers 10 that can be simultaneously lifted by the substrate pedestal 40 is limited to a small number, the total frictional force can be kept small.

As is clear from the above, in the substrate transfer apparatus, the substrate pedestal 40 allows the first cassette 3
The frictional force generated when the respective silicon wafers 10 in 1 are extracted is suppressed to a low level. Therefore, the first cassette 31
Therefore, the work of extracting the silicon wafer 10 by the substrate holder 40 is surely performed.

The above effect is particularly remarkable when the receiving grooves 40d, 40e, 40f formed in the substrate receiving table 40 have a substantially Y-shaped cross section as in this embodiment.

Further, the above effect is that when the support groove 32a engaging with the outer peripheral portion of the silicon wafer is provided in parallel with the first cassette 31 as in the present embodiment, the silicon wafer 10 and the support groove 32a are formed. Since the frictional force may be generated between the inner wall surface and the inner wall surface, the frictional force is particularly remarkable. However, even if such a supporting groove 32a is not formed in the cassette 31, a frictional force that causes the cassette to float up may be generated between the silicon wafer 10 and the cassette for some reason. Even in that case, the above configuration according to the present invention is useful.

Further, in this embodiment, FIG. 4 and FIG.
As shown in FIG.
e and 40f are set so as to gradually lower as going from the division 41 to the division 45, but the order of the steps is not limited to such a uniform change, and a low division next to the high division is provided. After the portion is provided, the height difference may be appropriately changed by, for example, providing the next higher division portion.

[0066]

As described above, according to the present invention, the receiving grooves juxtaposed on the substrate pedestal are divided into a plurality of divisions in the substrate alignment direction, and the divisions are mutually separated. It is formed with steps. According to this structure, when the substrate pedestal is inserted into the cassette to receive the substrate, the receiving groove for each of the dividing portions engages with the substrate in the order of the step from the higher step. Therefore, when a frictional force is generated between each substrate and the cassette due to various causes such as the inclination of the substrate in the cassette, the frictional force on all the substrates in the cassette does not act at the same time, and each of the division parts A relatively small frictional force generated on each substrate acts sequentially with a time difference. Therefore, even if the cassette is small and lightweight, it does not float up due to frictional force, and the work of extracting the substrate is surely performed. The above effect is particularly remarkable when the receiving groove formed in the substrate pedestal has a substantially Y-shaped cross section. Further, the above effect is particularly remarkable when a supporting groove that engages with the outer peripheral portion of the substrate is juxtaposed in the cassette because a frictional force may be generated between the substrate and the inner wall surface of the supporting groove. It However, even if such a support groove is not formed in the cassette, it is considered that a frictional force that causes the cassette to float up is generated between the substrate and the cassette for some reason, and even in that case. The present invention is useful.

[Brief description of drawings]

FIG. 1 is a perspective view of a substrate transfer device as an embodiment of the present invention.

FIG. 2 is a perspective view showing a substrate pedestal included in the substrate transfer device shown in FIG. 1 and a first cassette into which the substrate pedestal is to be inserted.

FIG. 3 is a front view showing a substrate supporting member included in the first cassette shown in FIG. 2 and a silicon wafer engaged with the substrate supporting member.

FIG. 4 is an enlarged perspective view of the substrate pedestal shown in FIG.

5 is a vertical cross-sectional view of the substrate pedestal shown in FIG.

6 is a front view showing an engagement state between a support groove formed in each substrate supporting member included in the first cassette shown in FIG. 2 and a silicon wafer.

7 is a diagram showing an engagement state between a silicon wafer and a receiving groove formed in the substrate pedestal shown in FIG.

FIG. 8 is a plan view showing an engagement state between the first cassette and the substrate pedestal shown in FIG. 2 and the silicon wafer.

FIG. 9 is a perspective view of a conventional substrate transfer device.

FIG. 10 is a plan view of a first traverser table included in the substrate transfer device shown in FIG.

11 is a plan view of a second traverser base included in the substrate transfer device shown in FIG. 9. FIG.

FIG. 12 is a perspective view showing a first cassette to be handled by the substrate transfer apparatus shown in FIG. 9 and a cleaning processing apparatus for cleaning a silicon wafer in the first cassette. is there.

13 is a vertical cross-sectional view of a first cassette handled by the substrate transfer apparatus shown in FIG. 9 and a silicon wafer housed in the first cassette.

FIG. 14 is a view taken along the line AA in FIG.

15 is a perspective view of a substrate pedestal included in the substrate transfer device shown in FIG.

16 is a front view showing an engagement state between a support groove formed in the first cassette shown in FIGS. 13 and 14 and a silicon wafer.

FIG. 17 is a diagram showing an engagement state between a silicon wafer and a receiving groove formed in the substrate pedestal shown in FIG.

FIG. 18 is a plan view showing an engagement state between the first cassette and the substrate pedestal shown in FIGS. 13 to 15 and the silicon wafer.

[Explanation of symbols]

 2 First Traverse Table 3 Second Traverse Table 5 Movable Base 8 Second Cassette 10 Silicon Wafer (Substrate) 18 Delivery Means 22 Support Shaft (of Delivery Means 18) 31 First Cassette 32 (First Cassette 31) Substrate support member 32a support groove 36 (first cassette 31) side member 40 substrate pedestal 40d, 40e, 40f receiving groove 41, 42, 43, 44, 45 partition section

Claims (6)

[Claims] 1. A receiving groove, which can engage with an outer peripheral portion of the substrate, is arranged in parallel, and the substrate can be aligned and supported so that its main surfaces are substantially parallel to each other. Each of the receiving grooves is arranged in the substrate alignment direction. A substrate pedestal characterized in that it is divided into a plurality of division parts, and each of the division parts is formed with a step. 2. The substrate pedestal according to claim 1, wherein the receiving groove has a substantially Y-shaped cross-sectional shape. 3. A substrate which can be inserted through a bottom opening of the cassette into a cassette capable of holding the substrates aligned such that their principal surfaces are substantially parallel to each other and receiving each of the substrates in an aligned state. The substrate pedestal is provided with a pedestal and a pedestal driving means for carrying the substrate pedestal and moving the substrate pedestal so that the cassette can be inserted into and removed from the cassette. A substrate extracting and accommodating device, wherein the receiving grooves are arranged in parallel, and each of the receiving grooves is divided into a plurality of dividing portions in the substrate alignment direction, and the dividing portions are formed with a step therebetween. 4. The substrate ejection / accommodating device according to claim 3, wherein the cassette is provided with a supporting groove that is engaged with an outer peripheral portion of the substrate. 5. A movable base for mounting a first cassette and a second cassette on different parts, each of which is capable of holding the substrates in alignment so that their main surfaces are substantially parallel to each other, and the first base.
Drive means for moving the movable base to position the first cassette and the second cassette at predetermined positions, and a bottom portion of each of the cassettes with respect to the first cassette and the second cassette provided at the predetermined position. A substrate pedestal that can be inserted through the opening and receives each of the substrates in an aligned state, and a receiver that carries the substrate pedestal and moves the first cassette and the second cassette so as to be inserted and removed. A base driving means and a delivery means for delivering the substrate to the substrate pedestal are provided, and the substrate pedestal is provided with receiving grooves in parallel with which the outer peripheral portion of the substrate can be engaged. A substrate transfer device, wherein each of the plurality of divisions is formed in the substrate alignment direction, and each division is formed with a step. 6. A support groove that engages with an outer peripheral portion of the substrate is formed in at least one of the first cassette and the second cassette in which the substrate is extracted. The substrate transfer device according to claim 5.