JPH11111810A - Cassette chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cassette chamber, which can perform mapping of a substrate by a small stroke in the vertically directions by providing two substrate detecting sensor parts. SOLUTION: A first substrate detecting sensor part 72, which is provided at the upper side from a substrate output/input part 20, and a second substrate detecting sensor part 74, which is provided at the lower side from the substrate output/input part, are provided. By moving a cassette mounting stage in the up and down directions, the presence or absence of a substrate W in a cassette C is detected by the first substrate detecting sensor part 72. The presence or the absence of a dummy substrate in a dummy cassette 26 is detected by the second substrate detecting sensor 74. Thus, the amount of the stroke of the cassette-mounting stage can be made less, and the height of the cassette chamber can be made small by that amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a cassette chamber directly or indirectly connected to a processing chamber for semiconductor wafers or the like.

[0002]

2. Description of the Related Art In general, a large number of substrates, for example, about 25 substrates, are provided at the front stage of a processing chamber for performing various processes on a substrate such as a semiconductor wafer, for example, a film forming process, an etching process and a thermal oxidation process. A cassette chamber for accommodating a cassette capable of accommodating substrates at one time is provided, and substrates are transferred between the cassette chamber and the processing chamber via a transfer chamber. In this case, it is important for the control system that controls the processing chamber and the transport system to know which of the 25 slots in the cassette has a substrate and which slot has no substrate. In general, a plurality of dummy substrates used for stabilizing processing conditions prior to actual processing of a product substrate or for monitoring processing contents are prepared in the cassette chamber,
It is also important from the viewpoint of processing to detect in advance which slot of the dummy cassette the dummy substrate is inserted into. The operation of detecting the presence or absence of the substrate in the cassette as described above is referred to as a mapping operation.
This mapping operation is performed by detecting the presence or absence of a substrate in the cassette using an optical sensor.

This state will be described in detail with reference to FIGS. 8 is a perspective view of a cluster tool device having a plurality of processing chambers, FIG. 9 is a plan sectional view thereof, and FIG. 10 is a sectional view showing a cassette chamber. This cluster tool device comprises two processing chambers 2, 4 and one transfer chamber 6 connected thereto, and two cassette chambers 8, 10 connected thereto.
It is mainly composed of The communication between the chambers can be shut off via a gate valve G which can be opened and closed in an airtight manner. The transfer chamber 6 is provided with, for example, a multi-joint type transfer arm 12 that can be bent and stretched and rotated, and the semiconductor wafer or the like accommodated in the cassette C in each of the chambers 8 and 10 by this one arm 12. The substrate W is loaded and unloaded.

The two cassette chambers 8 and 10 have substantially the same configuration, and FIG. 10 shows a cross section of one of the cassette chambers 8. The cassette chamber 8 has a cassette storage container 14 made of, for example, aluminum. At the lower portion on the front side, a cassette loading / unloading port 16 having a size capable of loading and unloading the cassette C is provided. Is provided with a gate door 18 which opens and closes the airtightly. Substrate loading / unloading ports 20 communicating with the transfer chamber 6 are provided substantially in the middle of the side wall substantially opposite to the cassette loading / unloading port 16, and the loading / unloading port 20 is a gate valve that opens and closes the airtightly. G is provided. In the cassette chamber 8, a cassette mounting table 24 attached to an elevating mechanism 22 provided to penetrate from the bottom in an airtight manner is provided so as to be able to move up and down, and the cassette C is placed horizontally on the cassette mounting table 24. To be mounted.

[0005] The cassette mounting table 24 includes a dummy cassette 2 accommodating a plurality of, for example, three dummy substrates DW.
6 and a cassette table 28 for directly mounting and supporting the cassette C. The lower surface of the cassette table 28 and the upper surface of the dummy cassette 26 are provided with a plurality of level adjusting screws for adjusting the horizontal level of the cassette table 28. They are connected by 30. Cassette C placed on the cassette table 28
Is configured as shown in FIG. 11 and FIG.

FIG. 11 is a perspective view showing an example of the cassette, and FIG. 12 is a sectional view showing the cassette. The cassette C is made of a resin that is hardly contaminated and hardly generates particles, for example, a Teflon resin. A front opening 32 for carrying the substrate in and out is formed in the front, and a rear opening 34 is formed in the rear on the opposite side. At the top of the cassette C, a handle 36 to be gripped when gripping the cassette C is provided. Further, on both sides of the inner side wall of the cassette C, narrow shelves 38, that is, slots are provided in multiple stages extending along the accommodation direction.
The edge of the substrate W is supported on the substrate to hold the substrate, that is, the semiconductor wafer. In the case of an 8-inch wafer, for example, 25 wafers can be accommodated in the cassette C, and in the case of a 12-inch wafer, for example, 13
One or 25 wafers can be accommodated.

In order to map the presence or absence of a substrate in the thus formed cassette C and the dummy cassette 26, an optical sensor including a light emitting element and a light receiving element is generally used. Since the side of the cassette C is covered with the side walls 40, 40, the substrate is mapped by passing the sensor light between the open front opening 32 and the rear opening 34. For this purpose, as shown in FIG. 10, for example, glass front viewports 42 and 44 are provided on a front wall 8A of the cassette chamber 8 and a rear wall 8B substantially opposed to the front wall 8A. A laser light emitting element 46 and a laser light receiving element 48 that generate light are provided. Thus, when the cassette mounting table 24 is raised, the substrate W in the cassette C and the dummy substrate DW in the dummy cassette 26 traverse the laser beam, and the presence or absence of the substrate W or the dummy substrate DW in the slot is detected. Then, mapping is performed.

[0008]

By the way, in the apparatus example as described above, in order to perform the mapping of the substrate W and the dummy substrate DW, as shown in FIG.
At least the height of the cassette C and the dummy cassette 26
And the height of the cassette mounting table 2
4 has to be raised, which causes a problem that the stroke becomes long and the overall height of the cassette chamber itself becomes considerably large. The present invention has been devised in view of the above problems and effectively solving them. An object of the present invention is to provide a cassette chamber in which two substrate detection sensor units are provided so that substrate mapping can be performed with a small vertical stroke.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has, on one side, a cassette unloading cassette which can be opened and closed for loading and unloading a cassette capable of accommodating a plurality of substrates in multiple stages. A cassette storage container having an entrance, and having a substrate loading / unloading opening which can be opened and closed to carry in / out a substrate in the cassette on the other side substantially opposite to the entrance; and a cassette for loading and unloading the cassette A first substrate detection sensor unit provided above the substrate loading / unloading port in a cassette chamber having a mounting table and a dummy cassette fixedly provided to accommodate a dummy substrate in the cassette mounting table; A second substrate detection sensor section provided below the substrate loading / unloading port, wherein the cassette mounting table is moved in the up-down direction so that the first substrate detection sensor section Wherein detecting the presence or absence of substrates in the cassette, which is constituted by the second substrate detection sensor unit to detect the presence or absence of the dummy substrate in the dummy cassette.

[0010] With this configuration, by raising the cassette by a predetermined stroke while the cassette is placed on the cassette mounting table, the first substrate detection sensor unit checks the presence or absence of the substrate in the cassette and performs this mapping. The second substrate detection sensor unit performs this mapping by checking for the presence or absence of a dummy substrate in the dummy cassette. Therefore, the stroke amount can be reduced as compared with the case where the mapping of the substrate and the dummy substrate is performed by one substrate detection sensor unit, and the height of the cassette chamber itself can be reduced accordingly. Therefore, the height of the cassette chamber can be reduced by the amount corresponding to the reduced stroke amount.

Further, the second substrate detection sensor section can also have a cassette presence / absence detection function for detecting whether or not a cassette is mounted on the cassette mounting table. Such first and second substrate detection sensors can be formed by a laser light emitting element that emits laser light and a laser light receiving element that receives this laser light. Furthermore,
When there is no dummy cassette, the presence or absence of a substrate in the cassette is determined by the first and second substrate detection sensor units.
For example, the region may be divided into upper and lower regions for detection.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the cassette chamber according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a partially cutaway perspective view showing a cassette chamber of the present invention, FIG. 2 is a schematic sectional view showing an attached state of a substrate detection sensor portion of the cassette chamber shown in FIG. 1, and FIGS. 3 to 5 are cassette chambers shown in FIG. 6 and 7 are enlarged sectional views showing a switch unit for detecting the presence / absence of a cassette. The same parts as those of the conventional apparatus described above are denoted by the same reference numerals and will be described. The major difference between the present invention and the conventional apparatus described above is that the present invention has a second substrate detection sensor unit for mapping a dummy substrate in a dummy cassette to reduce the entire stroke at the time of mapping. is there.

As shown, the cassette chamber 50 has:
It has a cassette container 52 made of, for example, aluminum and capable of vacuuming and N ₂ purging.
In the lower part of A, a cassette loading / unloading port 16 having a size capable of loading and unloading the cassette C is opened.
Is provided with a gate door 18 which opens and closes the airtightly. At a substantially middle level of the rear wall 52B substantially opposite to the cassette loading / unloading port 16, a substrate loading / unloading port 20 communicating with the transfer chamber 6 (see FIG. 9) is provided. Is provided with a gate valve G that opens and closes airtightly. The center level of the gate valve G serves as a transfer surface 54 for transferring the substrate W into and out of the transfer chamber 6, and transfers the substrate W through the substrate transfer port 20 while vertically moving the cassette C by one slot. It is supposed to do it.

In the cassette chamber 50, there is provided an elevating mechanism 22 which penetrates from the bottom portion 56 in an airtight manner. The cassette mounting table 24 is attached to the upper end of the elevating mechanism 22 so that the elevating mechanism can be moved up and down. The cassette C is placed horizontally on the cassette mounting table 24, that is, with the front opening 32 (see FIGS. 11 and 12) facing the transfer chamber 6 side. The cassette mounting table 24 includes a plurality of sheets,
For example, it comprises a dummy cassette 26 for accommodating three dummy substrates DW and a cassette table 28 for directly placing and supporting the cassette C as shown in FIGS. The structure of the dummy cassette 26 has a relatively large degree of freedom.
5 to 5, an optical path in the direction perpendicular to the paper surface can be formed through the inside of the cassette 26. The cassette table 28 and the upper surface of the dummy cassette 26 are connected by a plurality of level adjusting screws 30 for adjusting the horizontal level of the cassette table 28.

Although two level adjusting screws 30 are shown in the illustrated example, actually three level adjusting screws 30 are provided. The cassette table 28 is provided with a cassette presence / absence detection switch 58 as shown in FIGS. Specifically, the detection switch 58 fixes the base end of an elastic member 60 made of a leaf spring or the like to the lower surface of the cassette base 28 with a screw 62, and provides a push rod 64 at the tip thereof so as to stand upright. A light blocking plate 66 is attached downward. The push rod 64 penetrates the operation hole 68 formed in the cassette table 28, and the upper end thereof projects slightly upward from the horizontal level of the cassette table 28 (FIG. 6).
reference).

In the state shown in FIG. 6, an optical axis 70 of a second substrate detection sensor section, which will be described later, passes through a position where a black circle slightly below the light blocking plate 66 is located. Therefore, as shown in FIG. 7, when the cassette C is placed on the cassette table 28, the push rod 64 is pushed downward, so that the light blocking plate 66 blocks the laser beam passing through the optical axis 70. Thus, the presence or absence of the cassette C can be detected. In addition, the cassette mounting table 2
4 is merely an example, and a cassette mounting table having any structure may be used. For example, the cassette C may be finally expanded from the cassette loading / unloading port 26 to the outside by, for example, expanding the cassette table 28 or the like. 28 may be used.

A first substrate detection sensor section 72 for detecting the presence or absence of the substrate W in the cassette C is provided above the transport surface 54, more specifically, above the substrate carrying port 20. As shown in FIG. 2, the first substrate detection sensor 72 is provided on the front wall 52A at the cassette loading / unloading port 1.
The laser light emitting element 46 is provided slightly above the substrate 6 and a laser light receiving element 48 provided slightly above the substrate carrying-in / out port 20 on the rear wall 52B for receiving the laser light LA1. In order to reduce the height of the cassette chamber, it is preferable that the mounting level of the first substrate detection sensor unit 72 be as close to the substrate carrying-in / out opening 20 as possible. From the laser light emitting element 46, the laser light LA1 is emitted toward the laser light receiving element 48 located substantially in the horizontal direction, and the presence or absence of the laser light can be confirmed by the substrate W crossing the laser light.

On the walls 52A, 52B on which the light emitting element 46 and the light receiving element 48 are provided, for example, glass view ports 42, 44, which can see through the cassette chamber 50, are provided in an airtight manner. It is made to let. A second substrate detection sensor 74 (see FIGS. 1 and 2), which is a feature of the present invention, is provided below the substrate loading / unloading port 20 of the cassette storage container 52.
The second substrate detection sensor section 74 includes a laser light emitting element 76 disposed in a direction that intersects with the optical axis formed by the laser light emitting element 46 and the laser light receiving element 48.
And a laser light receiving element 78 for receiving the laser light. Specifically, the laser light emitting element 76 is provided on one side wall 52C of the cassette housing 52 via, for example, a view port 80 made of glass, and the laser light receiving element 78 is provided on the other side wall substantially opposed to the side wall 52C. 52D
Is also attached via a view port 82. The laser light LA2 from the laser light emitting element 78 at this time
Is emitted in the horizontal direction, and the optical axis 7 indicated by a black circle in FIG.
It passes through zero. In FIG. 6,
As shown in FIG. 3, the cassette mounting table 24 is in a state of being positioned at the lowermost end, that is, a position where the cassette C is loaded and unloaded.

Thus, when the dummy cassette 26 is raised, the presence / absence of the dummy substrate DW can be detected by temporarily blocking the laser beam LA2 from the laser light emitting element 76. Here, the second substrate detection sensor unit 74 is provided in a direction substantially orthogonal to the detection direction of the first substrate detection sensor unit 72, but is substantially parallel to the detection direction of the first substrate detection sensor unit 72. It may be provided as follows. In that case, the light emitting element 7 of the second substrate detection sensor unit 74
6 or the light receiving element 78 is attached to the gate door 18.

Next, the operation of the cassette chamber configured as described above will be described. First, the gate door 18 on the front side of the cassette chamber 50 is opened, and the cassette C is placed horizontally on the cassette mounting table 24 via the opened cassette carry-in / out port 16 (see FIG. 3). The placement of the cassette C may be performed by an operator or automatically by using an automatic transport mechanism or the like, and the form is not limited. When carrying in the cassette C, the cassette mounting table 24 is positioned at a predetermined position at the lowermost end by the elevating mechanism 22. Thus, the cassette C
Is supported on the cassette table 28 of the cassette mounting table 24, the push rod 64 of the cassette detecting member 58 projecting above the cassette table 28 as shown in FIG. As a result, the elastic member 60 is bent and deformed downward. Then, the light blocking plate 66 provided at the tip of the elastic member 60 cuts even the optical axis 70, and the second substrate detection sensor part 74 passing therethrough
Laser light LA from the laser light emitting element 76 (see FIG. 2)
2 will be blocked. As a result, the laser light receiving element 7
8, the laser beam LA2 does not reach, and the presence of the cassette C can be recognized.

As described above, when the presence of the cassette C is confirmed, the gate door 18 is closed, and then the operation shifts to the mapping operation. In this mapping operation, with the cassette C mounted, the cassette mounting table 24 is raised at a constant speed, for example, in the sequence shown in FIGS. Then, mapping is performed based on a change in the output of each of the board detection sensor units 72 and 74 at this time. That is, the cassette mounting table 24 is gradually raised by driving the elevating mechanism 22 from the state shown in FIG. In this case, as a matter of course, each slot in the cassette C or the dummy cassette 26 and the amount of rise are predetermined in one-to-one correspondence.

Therefore, as the cassette C rises,
If the laser light LA1 from the laser light emitting element 46 of the first substrate detection sensor unit 72 is temporarily cut off, it indicates that the substrate W is present in the corresponding slot. The substrate W does not exist. Similarly, if the laser beam LA2 from the laser light emitting element 76 of the second substrate detection sensor unit 74 is temporarily cut off, it indicates that the dummy substrate DW exists in the corresponding slot. The dummy substrate DW does not exist in the corresponding slot. In this way, the presence or absence of the substrate or the dummy substrate in each slot is confirmed, and the mapping is completed when the cassette mounting table 24 is raised to the position shown in FIG.

That is, the cassette mounting table 24 has only to be raised to a position where the bottom of the cassette C substantially reaches the horizontal level of the laser beam LA1 of the first substrate detection sensor unit 72. At this time, the dummy Mapping of the dummy substrate DW in the cassette 26 for the second substrate detection sensor unit 7
4 has been completed. Therefore, as compared with the case shown in FIG. 10, the stroke amount of the lifting mechanism 22 is reduced by the distance L1 corresponding to the height of the dummy cassette 26 and the height to the cassette table 28 supported thereon. can do. Therefore, the height of the cassette chamber 50 can be reduced by an amount corresponding to the distance L1, and
This downsizing can be achieved.

In an actual example of the apparatus, for example, when the cassette C can store 25 wafers of 8-inch size as substrates, the height L2 of the cassette C is about 200 mm and three dummy substrates are used. In the case of the dummy cassette 26 capable of storing the distance L1, the distance L1 is about 80 to 100 mm. Therefore, in this case, the height of the cassette chamber 50 can be reduced by about 100 mm at the maximum. Here, the laser light LA2 from the laser light emitting element 76 of the second substrate detection sensor unit 74 used for detecting the presence or absence of the dummy substrate DW is passed through the optical axis 70 shown in FIG. Since it is possible to determine the presence / absence of a cassette by detecting the bent state of the cassette, there is no need to separately provide a switch for determining the presence / absence of a cassette, and the apparatus can be simplified.

Further, in the embodiment, the case where the dummy substrate DW and the dummy cassette 26 are used has been described as an example, but the apparatus of the present invention can be applied even when these are not used. In this case, the laser light emitting element 76 and the laser light receiving element 78 of the second substrate detection sensor unit 74 are provided on the front wall 52A and the rear wall 52B, respectively. It is set so as to be substantially parallel to the laser light receiving element 48 (see FIG. 2).
Then, these first and second substrate detection sensor units 72,
The substrate W in the cassette C is mapped by dividing the section into sections by 74. For example, the first substrate detection sensor unit 72 detects the presence / absence of a substrate in the upper half slot in the cassette C and performs mapping, and the second substrate detection sensor unit 74 performs the remaining lower half slot in the cassette C. The mapping may be performed by detecting the presence or absence of the substrate.

Also in this case, the stroke of the cassette mounting table 24 can be reduced, and the height of the cassette chamber can be reduced accordingly. Here, the case where the cassette chamber is applied to the cluster tool device has been described as an example, but the present invention is not limited to this, and the present invention can be applied to a case where the cassette chamber is connected to a single processing chamber. Of course.
Further, although a semiconductor wafer has been described as an example of the substrate here, the present invention is not limited to this, and may be applied to an LCD substrate, a glass substrate, and the like.

[0027]

As described above, according to the cassette chamber of the present invention, the following excellent effects can be obtained. First and second substrate detection sensor units are provided at different positions in the cassette chamber, and the first substrate detection sensor unit maps the substrates in the cassette.
Since the dummy substrate in the dummy cassette is mapped by the substrate detection sensor section, the amount of stroke for raising the cassette mounting table can be reduced, and accordingly,
The height of the cassette chamber can be suppressed. Also, the second
The board detection sensor section of this product has a cassette presence / absence detection function to determine the presence / absence of a cassette to be placed on the cassette mounting table, so it is necessary to separately provide a complicated switch function to determine the presence / absence of a cassette. There is no. Furthermore, when the dummy cassette is not used, the presence and absence of the substrate in the cassette can be detected and mapped by, for example, dividing the area in the cassette into upper and lower portions by the first and second substrate detection sensor units. Also in this case, the stroke amount of the cassette mounting table can be reduced, and the height of the cassette chamber can be suppressed accordingly.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a cassette chamber of the present invention.

FIG. 2 is a schematic cross-sectional view showing a mounting state of a substrate detection sensor unit in the cassette chamber shown in FIG.

FIG. 3 is a sectional view showing the cassette chamber shown in FIG. 1;

FIG. 4 is a sectional view showing the cassette chamber shown in FIG. 1;

FIG. 5 is a sectional view showing the cassette chamber shown in FIG. 1;

FIG. 6 is an enlarged sectional view showing a switch unit for detecting the presence or absence of a cassette.

FIG. 7 is an enlarged sectional view showing a switch unit for detecting the presence or absence of a cassette.

FIG. 8 is a perspective view showing a cluster tool device having a plurality of processing chambers.

9 is a plan sectional view of the device shown in FIG.

FIG. 10 is a sectional view showing a cassette chamber.

FIG. 11 is a perspective view showing an example of a cassette.

FIG. 12 is a sectional view showing a cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 16 Cassette carrying-in / out 20 Substrate carrying-in / out 24 Cassette mounting stand 26 Dummy cassette 28 Cassette stand 46 Laser light emitting element 48 Laser light receiving element 50 Cassette room 52 Cassette storage container 72 First substrate detection sensor part 74 Second substrate detection sensor part 76 Laser light emitting element 78 Laser light receiving element LA1, LA2 Laser light DW Dummy substrate W substrate

Claims (4)

[Claims] 1. A cassette loading / unloading opening / closing port which can be opened / closed for loading / unloading a cassette capable of accommodating a plurality of substrates in multiple stages on one side, and a cassette loading / unloading opening substantially opposite to the cassette loading / unloading port. A cassette storage container having a substrate loading / unloading opening / closing port that can be opened / closed for loading / unloading a substrate, a cassette mounting table on which the cassette is mounted and moved up and down, and a cassette mounting table for accommodating dummy substrates. In a cassette chamber having a fixedly provided dummy cassette, a first substrate detection sensor section provided above the substrate carry-in / out port and a second substrate detection sensor provided below the substrate carry-in / out port The first substrate detection sensor unit detects the presence or absence of a substrate in the cassette by moving the cassette mounting table in the vertical direction, and detects the second substrate detection unit. A cassette chamber wherein the presence / absence of a dummy substrate in the dummy cassette is detected by an output sensor unit. 2. A cassette loading / unloading port which is openable and closable for loading / unloading a cassette capable of accommodating a plurality of substrates in multiple stages on one side, and a cassette loading / unloading port on the other side substantially opposed to the cassette loading / unloading port. In a cassette chamber having a cassette storage container having a substrate loading / unloading opening and closing capable of opening and closing a substrate for loading and unloading a substrate, and a cassette loading table for loading and unloading the cassette, the cassette chamber is provided above the substrate loading / unloading entrance. A first substrate detection sensor unit, and a second substrate detection sensor unit provided below the substrate carry-in / out port,
A cassette chamber, wherein the presence or absence of a substrate in the cassette is detected separately for each region by the first and second substrate detection sensor units by moving the cassette mounting table in a vertical direction. 3. The apparatus according to claim 1, wherein the second substrate detection sensor has a cassette presence / absence detection function for detecting whether a cassette is mounted on the cassette mounting table. Cassette room. 4. The apparatus according to claim 1, wherein each of the first and second substrate detection sensors comprises a laser light emitting element for emitting laser light and a laser light receiving element for receiving the laser light. Cassette room described in Crab.