JPH0581177B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to semiconductor wafers (hereinafter referred to as wafers).
The present invention relates to the configuration of a wafer transfer device used in CVD processing, etching processing, or inspection processing.

[Conventional technology]

2. Description of the Related Art Conventionally, there is one shown in FIG. 7 as one of the wafer transfer devices incorporated in semiconductor manufacturing equipment to transfer wafers. Hereinafter, its structure and operation will be explained based on the drawings.

In FIG. 7, reference numeral 2 denotes a wafer cassette having a wafer storage groove 2a, in which a plurality of wafers 1 are stored, one by one, horizontally and at regular intervals with the front surface (processing side) facing upward. Also,
4 is an elevating sludge, and an elevating screw shaft 5 and a guide shaft 6 are attached to the lower part of the elevating sludge. This elevating screw shaft 5 engages with a threaded portion 8a of a gear 8 that meshes with a gear 7 rotated by a motor _M1 for elevating.
The guide shaft 6 is supported so as to fit into the fitting portion 10a of the base 10. Therefore, when the motor _M1 is driven, the elevating stage 4 is raised or lowered by the feeding action of the screw. Note that the gear 8 is connected to the wafer cassette 2.
A disc 39 is attached with a slit cut therein corresponding to the rotation angle of the gear 8 when the elevating stage 4 moves up and down by an amount corresponding to the pitch of the wafer storage groove 2a. Detected by a sensor 40 such as a type sensor,
By driving and stopping the motor _M1 based on the signal, the elevating stage 4 is raised and lowered by a distance corresponding to the wafer storage groove pitch of the wafer cassette 2.

On the other hand, 41 is a wafer support portion that supports the wafer 1 . This wafer support portion 41 is provided with a vacuum suction port 42 and an annular hole 43 communicating therewith. Further, 44 is a wafer support part 41
A moving means for moving the rotary actuator 45 in a horizontal plane, which has a rotary actuator 45 for direction change attached to the lower part of the wafer support 41 and a gear 47 fixed to one end.
a forward and backward drive motor that rotates a feed screw shaft 46 that engages with a and a gear 48 that meshes with a gear 47;
It is composed of M ₂ . For this reason, motor M ₂
When driven, the wafer support section 41 moves forward or backward.

The wafer 1 is transferred as follows by the wafer transfer device configured as described above. That is, first, the elevating stage 4 on which the wafer cassette 2 is installed is set to its highest position. At this time, the height position of the upper end of the wafer support part 41 is adjusted so that it is located below the height position of the lowest wafer 1 stored in the wafer cassette 2 by the pitch of the wafer storage groove. Next, the motor _M2 is driven, and the wafer support part 41 starts moving forward along the feed screw shaft 46, and the wafer cassette 2
enter the vehicle and stop at a designated position. Then, when the motor _M1 is driven and the elevating stage 4 is lowered by the pitch of the wafer storage groove and stopped, the wafer 1
The back surface of the wafer is in contact with the wafer support. Here, the air inside the vacuum suction port 42 that has been cooled by the wafer 1 is exhausted from the annular hole 43 by a vacuum pump (not shown) or the like, and when the inside of the vacuum suction port 42 becomes negative pressure, the wafer 1
is attracted to the vacuum suction port 42, and the wafer support part 41
Fixed. In this state, the motor _M2 is driven to rotate in reverse, and the wafer support portion 41 begins to move backward and stops at a predetermined position. Further, by rotating the rotary actuator 45 by a predetermined angle, the wafer 1 is transported to the next station. Therefore, the wafer 1 is subjected to chemical treatment, physical treatment, or the like. By repeating the above operations,
A plurality of wafers 1 in a wafer cassette 2 are transported to the next station. Note that when storing wafers in the wafer cassette 2, the above-mentioned reverse operation is performed.
The wafers 1 are sequentially inserted into the wafer storage groove of the wafer cassette 2 starting from the top.

[Problem that the invention seeks to solve]

However, in the conventional wafer transfer device as described above, the surface of the wafer 1 (processing side surface) is directed upward to prevent the processing section from coming into contact with the wafer support section 41 and becoming contaminated. Although the wafer 1 was being transported, the processing area on the surface of the wafer 1 was sometimes soiled due to falling dust and the like during the transport. In addition, the lifting and lowering of the lifting stage 4 is controlled by a disk 39 attached to the gear 8.
Since this is performed based on the signal from the sensor 40 that senses the slit of
always stops after moving by the pitch of the wafer storage groove. Therefore, if the wafer 1 in the wafer cassette 2 is missing, empty transport is performed. This caused lost time and increased work loss.

This invention was created in view of the above-mentioned problems, and it is possible to support the wafer with the surface facing downward, and to transport the wafer to the next station without damaging the processing section. It is an object of the present invention to provide a wafer transfer device that is free from the risk of transfer.

[Means for solving problems]

In order to achieve the above object, the present invention provides a wafer cassette for horizontally storing a plurality of wafers one by one with their surfaces (processing surfaces) facing downward; and a fixing means for fixing the wafers. A wafer support part supports the wafer so that the outer peripheral part of the surface of the wafer comes into contact with the fixing means, and the wafer support part is moved in a horizontal plane to move the wafer support part into and out of the wafer cassette. a wafer handler comprising a moving means; a lifting means for raising and lowering the wafer cassette; detecting the position of the wafer to be transported in the wafer cassette;
a first detection means for transmitting a drive signal for causing the moving means to move the wafer support into the wafer cassette; a first detection means for detecting that the wafer is supported by the fixing means of the wafer support; a second detection means for sending a drive signal to stop the lifting and lowering and to cause the moving means to detach the wafer support from the wafer cassette; A first recess having a surface and a bottom that aligns with the outer circumference of the wafer, and a second recess that prevents the bottom from coming into contact with a processing section of the wafer.

[Effect]

In the wafer transfer apparatus according to the present invention configured as described above, a plurality of wafers are stored horizontally one by one in a wafer cassette with the front surface (processing side) facing downward, and the first detection means When the wafer detects the position of the wafer to be transferred within the wafer cassette, the wafer transfer position between the wafer cassette and the wafer handler is set. Based on this, the moving means of the wafer handler is activated, and the fixing means provided on the wafer support section is moved to a position directly below the wafer to be transferred within the wafer cassette. Next, the elevating means for elevating the wafer cassette is operated, and when the wafer and the fixing means come into contact with each other, the wafer is fixed with its surface facing downward. At the same time, when the second detection means detects that the wafer is fixed to the fixing means of the wafer support,
The lifting means stops. Since the fixing means provided on the wafer support unit fixes the wafer so as to come into contact with the outer circumference of the wafer surface, the process processing area on the wafer surface is not contaminated. Then, the wafer fixed to the fixing means of the wafer support part is kept with its surface facing downward.
It is transported to the next station by the moving means.

Since the fixing means provided on the wafer support section has the first recess, the wafer will not fall during transportation. In addition, this first recess not only fixes the wafer at its outer periphery, but also has a guide surface that slopes downward, that is, a tapered surface, so that the wafer is reliably centered and the wafer is prevented from shifting. be done.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a block diagram of a wafer transfer apparatus according to the present invention.

In Fig. 1, 2 is a wafer cassette that horizontally stores a plurality of wafers 1 one by one with their front surfaces (processing side surfaces) facing downward, and Fig. 2 (a front view of the wafer cassette 2 seen from the direction of the arrow) As shown in FIG. 2, wafer storage grooves 2a for storing wafers 1 are provided at equal intervals inside the wafer.

Further, 3 is an elevating means, which is constructed as follows. That is, a lifting screw shaft 5 and a guide shaft 6 are installed at the bottom of the lifting stage 4 on which the wafer cassette 2 is installed.
is attached, and the lifting screw shaft 5 engages with the threaded portion 8a of the gear 8 that meshes with the gear 7 rotated by the lifting drive motor _M1 , and the base 10 is connected to the base 10 through the gear 8 and the bearing 9. The guide shaft 6 is supported so as to fit into the fitting portion 10a of the base 10. For this reason, the motor
When _M1 is driven, the elevating stage 4 is raised or lowered by the feeding action of the screw.

Reference numeral 11 denotes a first detection means for detecting the position of the wafer 1 to be transferred within the wafer cassette 2, and is attached to the upper end of a sensor support 12 fixed on the base 10. Note that as the first detection means, for example, a photoelectric sensor or a capacitive sensor is used.

Reference numeral 13 denotes a wafer handler consisting of a wafer support part 14 and a moving means 23, which is usually installed inside a vacuum container 38.

As shown in FIG. 3, the wafer support section 14 includes:
A tapered first guide surface 16a that slopes downward inward and a bottom surface 16b that aligns with the outer circumference of the wafer 1.
the recess 16, the bottom surface 16, and the bottom surface 16b.
A fixing means 15 is provided which includes a second recess 17 formed by circular processing. As a result, when the wafer 1 is transferred between the wafer cassette 2 and the wafer support section 14, when the wafer 1 comes into contact with the guide surface 16a, the guide surface 16a
a, and is positioned on the bottom surface 16b that aligns with the outer circumference of the wafer 1. Bottom surface 16b
Since the second recess 17 is provided in the wafer 1, only the outer peripheral portion of the front surface of the wafer 1 is supported, and the processing section is not contaminated. Normally, in various processing steps of the wafer 1, it is necessary to align the wafer 1 when processing the wafer 1. Therefore, in this type of wafer transfer device, the wafer 1 is always kept at a predetermined position on the wafer support 14. It is important to transport it in a fixed manner. However, since the wafers 1 in the wafer cassette 2 are stored unevenly front to back and left to right,
As described above, it is necessary to position and fix the wafer to the fixing means 15 provided on the wafer support 14. Note that the flat portion 18 is for pushing in the wafer 1 stored in the wafer cassette 2 protruding from the wafer cassette 2, and bringing the wafer 1 into contact with the guide surface 16a. Also, 22 in Figures 1 and 3
is a second detection means for detecting whether or not the wafer 1 is supported by the fixing means 15 of the wafer support portion 14, and is, for example, a photoelectric sensor or a capacitance type sensor.

On the other hand, the moving means 23 is generally called a mechanical pantograph mechanism, and its structure and operation will be explained in detail below based on FIGS. 4 and 5. In FIG. 4, 24 is a rotating shaft rotated by a telescopic drive motor _M2 ,
A pulley 25 and a gear 26 are fixed. The central part of this rotating shaft 24 is connected to the main body 2 through a bearing.
7, and the upper end is supported by the first
is connected to one end of arm 28 of. 29 is a connecting shaft 32 to which a gear 31 is fixed, and a pulley 33
The second arm has a connecting shaft 34 to which the connecting shaft 32 is attached to the wafer support 14.
4 are respectively connected to the first arm 28 via bearings. Also, 35 is pulley 2
This is a timing belt for transmitting the driving force of No. 5 to the pulley 33. Note that the arm portion 30 consisting of the first arm 28 and the second arm 29 is provided as a pair, and a pair of gears 31
and 31 and the pair of gears 26 and 26 are arranged so as to mesh with each other, so when the motor _M2 is driven, the arm portion 30 performs the telescopic movement as shown in FIGS. 5a to 5c. That is, FIG. 5a shows a state in which the arm portion 30 is fully extended, FIG. 5b shows a state in which the arm portion 30 is being contracted, and FIG. 5c shows a state in which the arm portion 30 is completely contracted. Further, the main body 27 is connected to the vacuum container 3 via the bearing.
The main body 2 is supported by a support 36 fixed to the
Since the gear 27a formed at the bottom of the rotation drive gear 27a is engaged with the gear 37 rotated by the rotation driving motor _M3 , by driving the motor _M3 ,
The main body 27 rotates and the arm portion 30 pivots.
Therefore, by controlling the driving of motor M ₂ and motor M ₃ , it is possible to move wafer support 14 within a certain range of horizontal planes. Note that a pulse motor, an induction motor, or the like is used as the motor serving as the driving source.

The wafer transfer apparatus according to the present invention configured as described above carries out wafer transfer as follows.
When transporting the wafers 1, first, the wafer cassette 2 containing a plurality of wafers 1 with their surfaces facing downward is placed on the lifting stage 4, and
Wafer handler 13 with arm part 30 retracted
is placed opposite the wafer cassette 2. Now, when the first detection means 11 detects the position of the lowest wafer 1 stored in the wafer cassette 2, the transfer position of the wafer 1 between the wafer cassette 2 and the wafer handler 13 is set. The height positional relationship between the wafer cassette 2 and the wafer handler 13 is adjusted so that the wafer support section 14 is located slightly below the wafer 1 to be transferred. Here, the motor _M2 , which is the drive source of the moving means 23, is driven and the arm section 30 is extended, so that the wafer support section 14 enters the wafer cassette 2, and is moved to a predetermined position below the wafer 1 to be transported. When the wafer support section 14 is reached, the motor _M2 is stopped and the wafer support section 14
The fixing means 15 of is positioned at that position. Next, the motor _M1 , which is the drive source of the elevating means 3, is driven, and the elevating stage 4 is lowered, so that the wafer 1 comes into contact with the fixing means 15 of the wafer support 14 and is fixed. At the same time, the second detection means 22 detects this and stops the motor _M1 . When the wafer 1 is fixed to the fixing means 15 of the wafer support 14 in this way, the motor M ₂ is driven to rotate in the opposite direction to the above, and the arm 30 contracts, causing the wafer support 14 to move backward. However, when it retreats to a preset position, motor _M2
is stopped, and the wafer support section 14 is stopped at that position. Next, the motor M ₃ is driven and the arm section 30 rotates, so that the wafer support section 14 begins to rotate toward the next station. When the wafer support section 14 faces in the direction in which the wafer 1 is to be unloaded, the motor starts to rotate. _M3 is stopped and the wafer support 14 is stopped at that position. And again, motor _M2
is driven and the arm portion 30 extends,
The wafer 1 supported by the wafer support section 14 is transferred to the next station. At this time, if a well-known elevating means (not shown) is attached to the wafer handler 13, the wafer 1 is elevated at the transferred position and placed in the vacuum container 38, e.g.
It is fixed to a wafer support stand for the CVD processing process by vacuum suction or the like. When the transfer of wafer 1 is completed,
The wafer handler 13 returns to its initial state facing the wafer cassette 2. Note that when a control signal for taking out wafer 1 is input in this state, the wafer transport device repeats the above-mentioned operation, and the wafers 1 in the wafer cassette 2 are sequentially transported to the next station, starting from the lowest one. go.

Next, the operation of this apparatus when the wafer 1 is transferred to and stored in the wafer cassette 2 will be explained. When storing the wafer 1, first, the wafer 1 is placed on the fixing means 15 of the wafer support part 14 of the wafer handler 13 facing the wafer cassette 2, and the wafer 1 is placed in the uppermost position provided in the wafer cassette 2. The wafer cassette 2 and wafer handler 13 are inserted into the center of the upper wafer storage groove 2a.
Adjust the height positional relationship. Note that at this time, the second detection means 22 detects the wafer 1 supported by the fixing means 15 of the wafer support section 14. Now, when a control signal for storing the wafer 1 is input, the wafer support section 14 advances into the wafer cassette 2 while inserting the wafer 1 into the uppermost wafer storage groove 2a, and stops at a predetermined position. Next, the elevating stage 4 rises, and the wafer storage groove 2a lifts up the wafer 1 on the fixing means 15 of the wafer support part 14. Then, when the wafer 1 floats up from the fixing means 15 and the second detection means 22 can no longer detect the wafer 1, the elevating stage 4 stops and
The wafer support section 14 begins to retreat. When the wafer support part 14 returns to its initial state, the elevating stage 4 starts to rise again, but the wafer 1 inserted into the uppermost wafer storage groove 2a is positioned above the wafer support part 14 by the pitch of the wafer storage groove. It stops when the first detection means 11 detects that this has happened. Therefore, the next wafer 1 to be stored in the wafer cassette 2 is placed in the second wafer storage groove 2 from the top.
It will be inserted into a. By repeating the above operation, the wafer 1 is placed in the uppermost wafer storage groove 2a.
The wafers are sequentially inserted and stored in the wafer cassette 2.

Furthermore, another embodiment of the present invention will be described using FIG. 6. FIG. 6 shows a fixing means 15 for the wafer support section 14 to which a vacuum suction mechanism 19 is added. This vacuum suction mechanism 19 includes a vacuum suction groove 20 provided on the bottom surface 16b that contacts the outer peripheral portion of the wafer 1.
, an annular hole 21 communicating therewith, and a vacuum pump (not shown).
The vacuum pump starts operating at the same time as it comes into contact with the wafer 6b, and the outer circumference of the wafer 1 is sucked to securely fix the wafer 1. Note that if the fixing means 15 equipped with such a vacuum suction mechanism 19 is used, the wafer 1 can be held with the surface facing downward.
It is also possible to support the wafer 1 by suctioning the back surface thereof.

In the wafer transfer device according to the present invention described above, the wafer handler 13 and the wafer cassette 2
When transferring the wafer 1 between the wafer handler 13 and the wafer cassette 2, the wafer 1 is transferred using a lifting means 3 for lifting and lowering the wafer cassette 2. , there is no problem even if the wafer 1 is transferred.

〔Effect of the invention〕

According to the present invention, as a result of adopting the above configuration,
This prevents the processing section of the wafer 1 from being contaminated due to falling dust or the like during transportation. Further, when transferring the wafer 1 between the wafer cassette 2 and the wafer handler 13, the first detection means 11 directly detects the position of the wafer 1, and based on this, the transfer position of the wafer 1 is determined. Since wafers 1 are set in the wafer cassette 2, empty conveyance is prevented when the wafers 1 are missing, and an improvement can be expected in terms of work costs.

Furthermore, the first recess of the fixing means 15 eliminates the possibility that the wafer will fall during transportation. Further, due to the downwardly inclined guide surface of the first recess, the wafer 1 is accurately centered, and no positional deviation occurs.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention, in which FIG. 1 is a configuration diagram of a wafer transfer device,
Figure 3 is a front view of the wafer cassette, Figure 3 is a side view of the fixing means of the wafer support, Figure 4 is a configuration diagram of the wafer handler, Figure 5 is a diagram of the operation of the wafer handler, and Figure 6 is a diagram of the wafer handler. FIG. 7 is a side view of a fixing means portion of a wafer supporter showing another embodiment of the present invention.
Further, FIG. 7 is a configuration diagram of a conventional wafer transfer device. 1: Wafer, 2: Wafer cassette, 3: Lifting means, 11: First detection means, 13: Wafer handler, 14: Wafer support section, 15: Fixing means, 2
2: second detection means, 23: movement means.

Claims (1)

[Claims] 1. A wafer cassette that horizontally stores a plurality of wafers one by one with their front surfaces (processing surfaces) facing downward; fixing means for fixing the wafers is provided, and the outer periphery of the front surface of the wafers comes into contact with the fixing means. a wafer handler comprising a wafer support section for supporting the wafer in this manner; and a moving means for moving the wafer support section in a horizontal plane and for moving the wafer support section into and out of a wafer cassette; for raising and lowering the wafer cassette; a lifting means; detecting the position of the wafer to be transported in the wafer cassette;
a first detection means for transmitting a drive signal for causing the moving means to move the wafer support into the wafer cassette; a first detection means for detecting that the wafer is supported by the fixing means of the wafer support; a second detection means for sending a drive signal to stop the lifting and lowering and to cause the moving means to detach the wafer support from the wafer cassette; A wafer transfer comprising: a first recess having a surface and a bottom surface aligned with the outer periphery of the wafer; and a second recess that prevents the bottom surface from coming into contact with a processing section of the wafer. Device.