JP2001093964A - Wafer detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer detector capable of quickly detecting the housed condition of wafers in a wafer carrier in which many wafers are housed. SOLUTION: This wafer detector 100 comprises a light emitter 110, capable of irradiating two or more wafer housings 12 at the same time with light for a wafer carrier 10 having a plurality of wafer housing 12, 12, etc., formed therein, a CCD121 having two or more detectors for detecting an image obtained by the irradiating light which pass through the wafer carrier 10 and an electronic control unit 130 for detecting wafers 11, 11, etc., in the wafer carrier 10, based on signals obtained by the CCD121.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer detecting device, and more particularly to a wafer detecting device for detecting a position of a wafer housed in a wafer carrier.

[0002]

2. Description of the Related Art In the field of semiconductor manufacturing technology, semiconductor wafers to be processed (hereinafter, referred to as "wafers") are usually housed in wafer carriers. When a semiconductor device is manufactured by performing various processes (for example, annealing, ion implantation, etc.) on the wafer, the wafer is taken out of the wafer carrier, temporarily mounted on a wafer transport device, and then various processing devices ( For example, it is carried into a processing chamber).

[0003] When a wafer is mounted on a wafer carrier, a wafer detecting device detects in advance which position of the wafer carrier the wafer is stored in. Then, based on the detection result, the wafer is efficiently removed from the wafer carrier to the wafer transport device. A conventionally proposed wafer detection device scans the entire wafer carrier with light, or scans the wafer carrier itself, and forms an image (light pattern corresponding to the presence or absence of a wafer) represented by light passing through the wafer carrier. The light is detected by the light receiving element, and based on the detection result, it is detected which of the wafer storage units in the wafer carrier contains the wafer.

[0004]

By the way, in recent semiconductor manufacturing technology, in order to increase the throughput,
It is desired to reduce the time required for processing a wafer. However, the position detection of a wafer using a conventional wafer detection device has to scan the entire wafer carrier with light or scan the wafer carrier itself, and it takes a long time to detect the wafer position. .

In particular, a wafer carrier provided with a large number of wafer accommodating sections has a long scanning width (height) and a long detection time. If it takes a long time to detect the wafer position in this way, processing on the wafer must be stopped and waited during that time, which hinders an increase in throughput. The present invention has been made in view of such circumstances, and even when a large number of wafer storage units are provided in a wafer carrier, the position of a wafer, the position of a gap between wafers, It is an object of the present invention to provide a wafer detection device capable of detecting a storage state such as a gap amount.

[0006]

According to a first aspect of the present invention, there is provided a wafer detecting apparatus, comprising: a wafer carrier having a plurality of accommodation sections for accommodating wafers; Irradiation means capable of irradiating,
Detecting means for detecting, with two or more detection units, an image obtained by irradiation light passing through the storage unit or light reflected by the wafer when the wafer carrier is irradiated with light; and There is provided a wafer detection means for detecting a housing state such as a position of a wafer in a wafer carrier, a position of a gap between wafers, and an amount of a gap between wafers based on a signal obtained by the detection unit. By the operation of the irradiating means and the detecting means, it is possible to detect at least two or more housing portions the housing state such as the position of the wafer, the gap position, and the gap amount at a time.

In the wafer detecting device according to the present invention, the irradiating means may include a light source and a light emitting unit for converting the light from the light source into parallel light capable of simultaneously irradiating the two or more housing units. Lens. With this light emitting unit lens, the width of the light generated from one light source can be increased or the area irradiated with the light can be increased to irradiate two or more housing units with light for wafer detection. .

In a third aspect of the present invention, the detecting means includes a plurality of light receiving elements (preferably, a CCD);
A light receiving unit lens for forming an image obtained by the irradiation light or the reflected light on a light receiving unit provided with the plurality of light receiving elements. By using the light receiving unit lens, even if the detecting unit (for example, CCD) having a relatively small light receiving area and including a plurality of light receiving elements, the position of the wafer, the gap position, and the gap for at least two or more storage units. It is possible to detect the storage state such as the amount.

According to a fourth aspect of the present invention, the irradiating means and the detecting means are interlocked with each other by a driving means, and are relatively movable in the vertical direction with respect to the housing. . Since the irradiating means and the detecting means can move in conjunction with each other, even if the height of the wafer carrier is high or the irradiating means and the detecting means are relatively small, by moving these, the entire wafer carrier can be moved. Of the wafer, the gap position, the gap amount, and the like in the accommodation section can be detected.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. This first embodiment is described in claim 1,
This corresponds to claims 2 and 4. As shown in FIG. 1, the wafer detection apparatus 100 according to the first embodiment includes a light emitting unit (irradiation unit) 110 installed so that irradiation light is directed to the wafer carrier 10, and
A light receiving unit (detection unit) 120 facing the light emitting unit 110;
An electronic control unit (wafer detecting means) 130 for processing a signal sent from the light receiving unit 120 is provided.

As shown in FIG. 1, a wafer carrier 10 in which the position of the wafer 11, the position of the gap between the wafers 11, and the amount of the gap are detected by the wafer detecting apparatus 100, as shown in FIG.
Are provided in the vertical direction in a plurality of stages (nine stages in the illustrated example).
The light emitting section 110 of the wafer detection apparatus 100 includes a holding section 113 having a light source 111 and a light emitting section lens 112 therein, a light emitting section support 114 for supporting the holding section 113 movably in the vertical direction (the direction of the arrow in the figure). And a motor (driving means) 115 disposed on the light emitting portion support 114 to move the entire holding portion 113 up and down along the guide groove 114A. The light emitting unit lens 112 emits the irradiation light from the light source 111 to the wafer accommodation unit 1 in the wafer carrier 10.
Are converted into parallel light that is simultaneously irradiated to 2, 12,.

On the other hand, the light receiving section 120 includes a holding section 123 on which a CCD (plural light receiving elements) 121 is arranged, and a light receiving section support for supporting the holding section 123 movably in the vertical direction (the direction of the arrow in the figure). And a motor (driving means) 125 which is arranged on the light receiving portion support 124 and moves the entire holding portion 123 up and down along the guide groove 124A.

Here, the CCD 121 of the light receiving section 120 is
When light is emitted from the light emitting unit 110 to the wafer carrier 10, the light passing through the wafer storage units 12, 12... In the wafer carrier 10 is applied to the light receiving surface of the CCD 121. Appeared images (bright and dark patterns according to the presence or absence of the wafer 11) are detected at two or more points.

A signal representing an image (light / dark pattern) obtained by the CCD 121 is sent to an electronic control unit 130. The electronic control unit 130 includes an amplifier 131 for amplifying an electric signal representing an image (light / dark pattern) from the CCD 121, an A / D converter 132 for digitally encoding the signal amplified by the amplifier 131, a digitally encoded signal 133, an arithmetic circuit 134 for processing data imported to the memory 133, and an arithmetic circuit 1
An output circuit 135 for outputting the signal processed at 34
And is constituted by.

The electronic control unit 130 further includes an input circuit 137 for inputting an external command signal to the arithmetic circuit 134, a signal for irradiating the light source 111 of the light emitting unit 110 with light, and a motor 115 of the light emitting unit 110. Light receiving unit 120
Circuit 13 for outputting a signal for driving the motor 125
6. In the wafer detecting device 100 configured as described above, the motors 115 and 125 built in the light emitting unit 110 and the light receiving unit 120 respectively include the electronic control unit 1.
Driven by a signal from the light source 30, the holding unit 113 of the light emitting unit 110 and the holding unit 123 of the light receiving unit 120 can move relatively in the vertical direction with respect to the wafer accommodation units 12. At this time, the holding units 113 and 123
The optical axis L1 of the light emitting unit lens 112 moves up and down in conjunction with each other so as to be always at the same height as the center S1 of the CCD 121.

When the wafer detecting device 100 detects the wafers 11, 11,... Accommodated in the wafer accommodating portions 12, 12,... Of the wafer carrier 10, the electronic control unit 130 first controls the motors 115, 125. Driven. By driving the motors 115 and 125, the holding unit 113 and the holding unit 123 are moved to predetermined positions.
Next, light from the light source 111 is emitted toward the wafer carrier 10. At this time, the light from the light source 111 is converted into parallel light by the light emitting unit lens 112, and the parallel light is used to convert the light into a plurality of wafer accommodating parts 12, 12,.
) Are illuminated simultaneously.

The wafer accommodating portion 12 of the wafer carrier 10
The image (bright and dark pattern) corresponding to the presence or absence of the wafer 11 appears on the light receiving surface of the CCD 121 with the light having passed through. CC
D121 detects this image (light and dark pattern) that has appeared on the light receiving surface. The CCD 121 generates an electric signal representing a light and dark pattern, and converts the electric signal into an electronic control unit 130.
Send to

Based on the electric signal, the electronic control unit 130 controls the wafer accommodating section 12 of the wafer carrier 10,
12 and the gap position between the wafers 11, 11 and the amount of the gap are detected. The wafer 11 in the wafer carrier 10,
When the position and the like of 11 are detected, the electronic control unit 13
0 outputs a drive signal to the motors 115 and 125 to move the holding units 113 and 123 in the vertical direction by a fixed amount. Then, at the position after the movement, the position and the like of the wafers 11, 11,... Are detected again according to the above procedure.

FIG. 2 is a perspective view showing a transfer section of a semiconductor processing apparatus 200 using the wafer detection apparatus 100.
On the substrate 201 of the semiconductor processing apparatus 200, the wafer carrier 10, the wafer detection apparatus 100, the wafer transport apparatus 21
0, a wafer receiving device 220 is arranged. The substrate 201 of the semiconductor processing apparatus 200 has a wafer transport device 2
There are provided guide grooves 202 for moving 10 in the X-axis direction (indicated by an arrow X in the figure).

The wafer conveying device 210 is provided with the guide groove 20.
2, 202, and a Y-axis stage 213, which moves on the X-axis stage 211 along the guide grooves 212, 212 on the X-axis stage 211.
And the support 21 integrally provided on the Y-axis stage 213
4 and a wafer suction portion 215 that can move up and down with respect to the column 214 along the guide groove 216.

The wafer suction section 215 has two suction surfaces so that two wafers 11 can be loaded simultaneously. On the other hand, the wafer receiving device 220
2 so that two receiving surfaces 221A can be processed simultaneously.
221A, and is attached to the pedestal 223 so as to be able to rotate around the support column 222.

The semiconductor processing apparatus 20 constructed as described above
The loading / unloading operation of the wafers 11, 11,... At 0 is described with reference to the timing chart of FIG. In this timing chart, the time from t00 to t14 is
The first wafer unloading / loading operation is shown, and the time after t21 indicates the second wafer unloading / loading operation. First, t
Between 00 and t01, the motors 115 and 125 are driven to move the holding unit 113 of the light emitting unit 110 and the holding unit 123 of the light receiving unit 120 of the wafer detection device 100.

Next, between the time points t02 and t03, the light emitting section 110 sends the wafer accommodating sections 12 and 1 of the wafer carrier 10 to each other.
2 (for example, light is irradiated toward the wafer accommodating section 12 from the top of FIG. 1 to the third stage), and an image (light and dark pattern according to the presence or absence of the wafer 11) obtained by the irradiation of the light is shown. An electric signal is generated at the CCD 121, and this electric signal is
Input to the electronic control unit 130. Then, based on this electric signal, the electronic control unit 130 detects the position, gap position, and gap amount of the wafers 11, 11,... In the wafer carrier 10.

The wafer 11 from the electronic control unit 130
The main controller (not shown), which has received a signal indicating the housing state such as the position of the gap, the gap position, the gap amount, etc., removes the specific wafer (processing target) 11 from the wafer carrier 10 by the wafer suction unit 215. Is raised to a predetermined height in accordance with the height of the wafer accommodating section 12 in which the wafer 11 is accommodated (between t03 and t04).

Next, the main control unit controls the Y-axis stage 21
3 is moved in the Y-axis direction on the X-axis stage 211 so that the wafer 11 to be processed is sucked by the wafer suction unit 215. After sucking the wafer 11, the Y-axis stage 213 is moved again in the Y-axis direction and returned to the original position (t05 to t
06). Then, the wafer 11 is moved to the wafer suction unit 21.
The main controller is mounted on the X-axis stage 2
11 is moved in the X-axis direction, and the wafer 11 on the wafer suction unit 215 is moved to the receiving surface 221A of the wafer receiving device 220.
(Between t06 and t09).

Thereafter, the wafer 11 mounted on the receiving surface 221A is carried out into another processing apparatus (processing chamber) and subjected to predetermined processing such as annealing (t09 to t09).
11 time points). Meanwhile, on the wafer carrier 10 side, the holding units 113 and 123 are moved up and down so as to face the wafer storage units 12, 12... Of the next stage (fourth stage in FIG. 1) (between t06 and t07). ).

In this state, the wafer carrier 10
Of the wafer storage units 12, 12,... Are irradiated with light, and the wafers 1 in the wafer storage units 12, 12,.
, The gap position, and the gap amount are detected (t
08 to t10).

When the processing on the transferred wafer 11 is completed (time t11), a series of processing for returning the wafers 11, 11,... From the wafer receiving device 220 to the wafer carrier 10 is performed in the reverse order (t11). X stage movement between time t12 and Y stage movement between time t13 and t14). In the subsequent processing (t21 to t32), the wafers 11, 11
.. Have already been detected, the wafers 11, 11
Are carried out continuously.

As described above, in the first embodiment, the position, gap position, gap amount, and the like of the wafers 11, 11,... In the wafer accommodating section 12 can be detected in a short time by the wafer detection device 100. Wafer 11,1 needed
Waiting time during the detection of the positions of 1... Is not required, and the throughput of processing on the wafer 11 is improved. still,
As in the present embodiment, if the accommodation state of the wafer 11 (the position of the wafer, the position of the gap between the wafers, the amount of the gap between the wafers, etc.) is detected by transmitting the light from the light emitting unit 110 through the wafer carrier 10 ( The light reaching the light receiving unit 120 as in the case of using reflected light is detected by the wafers 11, 11,.
Can be accurately detected without being affected by the direction of the notch (orientation or notch).

(Second Embodiment) Next, a second embodiment of the present invention will be described.
A description will be given of the wafer detecting apparatus 300 according to the embodiment with reference to FIG. This second embodiment is described in claim 1
To claim 3. Note that the wafer carrier 10 to be detected by the wafer detection device 300 of this embodiment is the same as the wafer carrier 10 of the first embodiment,
Further, the semiconductor processing apparatus using the wafer detection apparatus 300 is the same as the semiconductor processing apparatus 200 (FIG. 2) of the first embodiment, and a detailed description thereof will be omitted.

The wafer detecting device 3 according to the second embodiment
00 is that the light emitting unit 310 is configured so that the light from the light source 311 can irradiate all the wafer accommodating sections 12, 12... Of the wafer carrier 10 at a time, and that the wafer accommodating sections 12, 12,. After passing the irradiation light, a relatively small C
The point that the light receiving section lens 322 is provided in the light receiving section 320 so that the CD (plural light receiving elements) 321 can detect at one time is that the wafer detecting apparatus 10 of the first embodiment described above.
Different from 0.

Specifically, as shown in FIG. 4, the light emitting section 310 of the wafer detecting apparatus 300 includes a light source 311 and a light source 3
And a light emitting unit lens (condensing lens) 312 for condensing the light from the light source 11 and converting it into parallel light that is simultaneously irradiated toward all the wafer accommodating parts 12, 12,. On the other hand, the light receiving unit 320 includes a CCD 321 and a CCD.
And a light receiving unit lens 322 for forming an image (bright and dark pattern) obtained by the irradiation light passing through the wafer accommodating units 12, 12.

With the provision of the light receiving lens 322 in this manner, the wafer accommodating portions 12, 12.
An image (light and dark pattern) appearing by the irradiation light passing through the CCD 321 is formed on the light receiving surface of the CCD 321.
Can detect the entire image. CCD
321 converts the detected result into an electric signal, and sends the electric signal to the electronic control unit 330.

The electronic control unit 330 includes a CCD 321
An electric signal representing an image (light / dark pattern) from the
The signal is amplified by 1 and digitally encoded by the A / D converter 332, and is fetched into the memory 333 as data. The data fetched into the memory 333 is processed by the arithmetic circuit 334, and then output to an external main controller (not shown) via the output circuit 335.

As described above, according to the wafer detecting apparatus 300 of the second embodiment, the irradiation light from the light emitting section 310 irradiates the entire wafer carrier 10 at a time, and the light passing through the wafer carrier 10 at this time is used. Since the entire obtained image (light and dark pattern) is detected at once by the CCD 321, the wafers 11, 1 in the wafer carrier 10 can be quickly moved without moving the light source 311 or the CCD 321.
.., The gap position, and the gap amount can be detected. As a result, the processing throughput for the wafers 11, 11,... Is further improved.

The light source 311 of the electronic control unit 330
The functions of the input circuit 337 and the drive circuit 336 that perform control of the electronic control unit 130 are substantially the same as those of the electronic control unit 130 according to the first embodiment, and a detailed description thereof will be omitted. still,
Also in the present embodiment, the accommodation state of the wafer 11 (the position of the wafer, the position of the gap between the wafers, the amount of the gap between the wafers, etc.) is detected by transmitting the light from the light emitting unit 310 through the wafer carrier 10 ( The light reaching the light receiving section 320 as in the case of using the reflected light is detected by the wafer 11, 11 as in the case of using the reflected light.
.. Are not affected by the direction of the notch (orientation or notch), and accurate wafers 11, 11.
Can be detected.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
The embodiment will be described with reference to FIG. 5 and FIG. Note that the third embodiment corresponds to claims 1 to 4. The wafer detection device 400 according to the third embodiment includes a wafer 11, 11 in a wafer carrier 40 whose back surface 40C (FIG. 6) is covered with a material that does not transmit light.
... is to be detected.

[0038] Wafer detection apparatus 400 of the third embodiment
As shown in FIGS. 5 and 6, the light emitting unit 410 is arranged so that the irradiation light is incident on the wafer carrier 40 at a certain angle, and the light emitting unit 410 is arranged so that the reflected light from the wafer 11 can be incident. It comprises a light receiving unit 420 and an electronic control unit 430 that processes a signal sent from the light receiving unit 420 and detects the position of the wafer 11 in the wafer carrier 40 based on the processed signal.

As shown in FIGS. 5 and 6, the light emitting section 410 includes a holding section 413 having a light source 411 and a light emitting section lens 412 built therein, and a light emitting section for supporting the holding section 413 movably in the vertical direction. Part support 414 and light emitting part support 414
And a motor 415 for vertically moving the holding portion 413 along the guide groove 414A.

Here, the light emitting unit lens 412 is
1 is converted into parallel light that simultaneously irradiates the wafer accommodating portions 42, 42,... In the wafer carrier 40. On the other hand, as shown in FIGS. 5 and 6, the light receiving section 420 includes a holding section 423 in which the CCD 421 is disposed,
The light receiving portion support 424 supports the holding portion 423 in a vertically movable manner, and a motor 425 provided on the light receiving portion support 424 to move the holding portion 423 up and down along the guide groove 424A. .

Here, the CCD 421 has a plurality of light receiving elements (detection units),
The purpose of this is to detect, at two or more points, an image (a light / dark pattern corresponding to the presence / absence of the wafer 11, 11,...) That appears on the light receiving surface of the CCD 421 by the reflected light from 1, 11,. When the wafers 11, 11,... In the wafer carrier 40 are detected by the wafer detection device 400 configured as described above, first, as in the first embodiment,
The holding units 413 and 423 of the light emitting unit 410 are moved to predetermined positions.

Next, light is emitted from the light emitting section 410 toward the wafer carrier 40. Due to this irradiation, the irradiated light is applied only to the portion where the wafer 11 is present.
And the reflected light is imaged on the light receiving surface of the CCD 421 of the light receiving section 420 arranged on the optical path. This image appears as a light and dark pattern according to the presence or absence of the wafer 11. The CCD 421 detects this image (bright and dark pattern), converts it into an electric signal, and sends it to the electronic control unit 430.

In the electronic control unit 430, the CCD 42
1 is amplified by an amplifier 431 and is digitally encoded by an A / D converter 432.
3 The data fetched into the memory 433 is processed by the arithmetic circuit 434, and then the output circuit 43
5 to an external main controller (not shown). As a result, the electronic control unit 430 can detect the positions of the wafers 11, 11,...

As described above, according to the wafer detecting device 400 of the third embodiment, even if the wafer carrier 40 whose back surface 40C is covered with a material that does not transmit light, the wafer housed inside the wafer carrier 40, 11, 11... Position and the like can be detected quickly. In the above-described first to third embodiments, an example has been described in which an image is detected by the CCDs 121, 321 and 421. However, an optical sensor other than the CCD having a plurality of light receiving elements is used. You may.

[0045]

According to the above-described wafer detecting apparatus of the first aspect, the irradiation means simultaneously irradiates two or more receiving portions of the wafer carrier with light, and reflects the irradiation light when the light is irradiated or the wafer. Since the image obtained by the reflected light is detected by two or more detection units of the detection means at the same time, the two or more wafers in the wafer carrier are detected based on the signal obtained by the detection means. The position, the gap position, the gap amount and the like can be simultaneously detected. As a result, when a wafer is carried in / out of a wafer carrier, the time required for wafer detection is reduced, and the throughput of processing on the wafer is improved.

According to a second aspect of the present invention, there is provided a wafer detecting apparatus comprising:
The illuminator lens allows a single light source to simultaneously illuminate two or more receiving portions of the wafer carrier with parallel light. Further, according to the wafer detecting device of the present invention, it is possible to detect the wafer accommodation state such as the position, the gap position, and the gap amount of a large number of wafers with a small CCD.

According to a fourth aspect of the present invention, there is provided a wafer detecting apparatus comprising:
By moving the irradiation unit and the detection unit up and down in conjunction with each other, the irradiation unit smaller than the wafer carrier and the detection unit allow the wafer accommodation state such as the position of the wafer in the wafer carrier, the gap position, the gap amount, and the like. Can be detected.

[Brief description of the drawings]

FIG. 1 is a wafer detection apparatus 1 according to a first embodiment of the present invention.
It is a figure which shows the whole structure of 00.

FIG. 2 is a perspective view showing a semiconductor processing apparatus 200 using the wafer detection apparatus 100 of the present invention.

FIG. 3 is a timing chart showing unloading / loading in of a wafer 11 in the semiconductor processing apparatus 200.

FIG. 4 shows a wafer detecting device 3 according to a second embodiment of the present invention.
It is a figure which shows the whole structure of 00.

FIG. 5 shows a wafer detecting device 4 according to a third embodiment of the present invention.
It is a perspective view which shows the whole structure of 00.

FIG. 6 shows a wafer detecting apparatus 4 according to a third embodiment of the present invention.
It is a figure which shows the whole structure of 00.

[Explanation of symbols]

10, 40 Wafer carrier 11 Wafer 12, 42 Wafer accommodating section (accommodating section) 100, 300, 400 Wafer detecting device 110, 310, 410 Light emitting section (irradiating means) 112, 312, 412 Light emitting section lens (detecting means) 121, 321,421 CCD 120,320,420 Light receiving unit 130,330,430 Electronic control unit (wafer detecting means) 322,422 Light receiving unit lens

Claims (4)

[Claims] An irradiation unit configured to simultaneously irradiate two or more accommodation units with light on a wafer carrier having a plurality of accommodation units for accommodating a wafer; and Detecting means for detecting an image obtained by irradiation light passing through the storage unit or reflected light reflected by the wafer by two or more detection units; and based on signals obtained by the two or more detection units. A wafer detecting means for detecting a wafer accommodation state such as a position of a wafer in a wafer carrier, a gap position between wafers, and a gap amount between wafers. 2. The irradiating means includes a light source and a light emitting unit lens for converting light from the light source into parallel light capable of simultaneously irradiating the two or more housing units. The wafer detection device according to claim 1. 3. The detecting means includes: a plurality of light receiving elements; and a light receiving section lens for forming an image obtained by the irradiation light or the reflected light on a light receiving section provided with the plurality of light receiving elements. The wafer detection device according to claim 1 or 2, wherein: 4. The apparatus according to claim 1, further comprising a driving unit that moves the irradiation unit and the detection unit relative to each other in an up-down direction relative to the storage unit. Item 4. The wafer detection device according to any one of Items 3.