JP2992854B2 - Substrate single wafer detection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-wafer detecting apparatus for a substrate, and more particularly, to detecting the presence, number, and arrangement of a plurality of substrates such as wafers arranged at appropriate intervals. The present invention relates to an apparatus for detecting a single-wafer substrate.

[0002]

2. Description of the Related Art Generally, semiconductor devices and liquid crystal display devices (L
In the manufacturing process of CD), a plurality of wafers are arranged and accommodated in a cassette and transported, or a plurality of wafers taken out of the cassette are transported in an arranged state, and each wafer is appropriately processed. Has been given. Therefore, in the wafer transfer process, it is important in wafer processing to grasp the number of wafers and to arrange the wafers in an appropriate state.

Therefore, conventionally, as means for detecting the number of wafers and the arrangement of the wafers, the number of wafers and the like are detected based on the presence / absence of the arranged wafers by using a transmitted light detecting means comprising a light emitting portion and a light receiving portion. I have. In this case, as the transmitted light detection means, a light-emitting portion and a light-receiving portion are arranged corresponding to the number of wafers to be arrayed (Japanese Utility Model Application Laid-Open No. 61-1264).
Japanese Patent Application Laid-Open No. 61-71383 and Japanese Patent Application Laid-Open No. 61-71383, which detect a number of wafers by scanning a set of a light emitting unit and a light receiving unit in the arrangement direction of wafers.
No. 99344, JP-A-61-99345, JP-A-61-129340 and JP-A-1-2868.
No. 3) is known.

[0004]

However, in the former case, that is, in the case of arranging the light emitting units and the light receiving units for each wafer, the number of the light emitting units and the light receiving units is required to be equal to the number of wafers, so that the apparatus becomes large. There was a problem of becoming.
Further, the latter, that is, the one that scans a pair of light emitting unit and light receiving unit in the wafer arrangement direction requires a moving mechanism,
The apparatus has become complicated and large in size, and required accuracy for scanning.

Therefore, recently, as an improvement of the former, half the number of light-emitting portions and light-receiving portions, which are half the number of arranged wafers, are alternately arranged on both sides of the row of wafers so as to correspond to the positions between adjacent wafers. ) sheet detecting device of a wafer having a transmission light type detecting means comprising in sequence has been proposed. According to this improved device, the detection means can be constituted by the minimum number of light-emitting parts and light-receiving parts required without mechanically scanning the detection means, thereby simplifying the structure of the whole apparatus. And the size of the device can be reduced.

However, in this improved device, when the light emitting section and the light receiving section are selectively operated to detect the presence or absence of an individual wafer, light from the light emitting section is arranged together with the wafer to be detected. There is a possibility that the light may be reflected by another wafer and enter the light receiving unit, thereby causing a detection malfunction. In particular, when detecting a transparent or translucent object such as a quartz wafer, the light transmitted through the wafer is reflected by an adjacent wafer, and a large amount of reflected light is generated, making detection impossible. Therefore, further improvement has been desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a transparent or translucent wafer with a simple device configuration in which a required minimum number of light emitting units and light receiving units are arranged without scanning a detection unit. It is another object of the present invention to provide a single-wafer detection apparatus capable of detecting the presence, number, and arrangement state of the wafers with high accuracy.

[0008]

In order to achieve the above object, a first substrate single-wafer detecting apparatus of the present invention comprises a substrate for detecting presence / absence, number, and arrangement state of substrates arranged at appropriate intervals. A plurality of light emitting units and light receiving units of the transmitted light type detecting means are alternately arranged on both sides of the substrate row, and a polarizing filter is provided on at least one of these light emitting units and light receiving units. It is. In this case, the directions of the transmission axes of the polarizing filters on the light emitting unit side and the light receiving unit side are both set parallel to the substrate surface in the proper arrangement state.

The second substrate single-wafer detecting apparatus according to the present invention, similarly to the first aspect, comprises a substrate for detecting the presence / absence, number, and arrangement state of substrates arranged at appropriate intervals. Assuming a leaf detecting device, a plurality of light emitting portions and light receiving portions are alternately arranged on both sides of a substrate row, and transmitted light type detection means, and the light emitting portions individually emit light when the substrate is not arranged at all. The storage means for storing in advance the data of the amount of received light detected by the light receiving section when the light is received, and the storage means for storing the amount of received light when the substrate is actually detected. A correction means is provided for subtracting a constant value from the value of the amount of received light detected by the light receiving units located on both sides of the light receiving unit that detects the amount of received light when the value exceeds the data value.

Further, the third substrate single-wafer detecting apparatus of the present invention detects the presence / absence, number, and arrangement state of substrates arranged at appropriate intervals, similarly to the first and second inventions. Assuming a single-substrate detection device for a substrate, a transmitted-light type detection unit in which a plurality of light-emitting units and light-receiving units are alternately arranged on both sides of a substrate row, and a state in which the substrate is not arranged at all.
When the light emitting sections are individually lit,
Data of the amount of received light detected by the light receiving unit is stored in advance.
Storage means, moving means for relatively moving the substrate and the detecting means, and when the end of the substrate passes through the optical axis of light from the light emitting part to the light receiving part of the detecting means by the moving means. While detecting the change in the amount of light received by the light receiving section,
A detecting means for detecting the presence or absence of the substrate from the detection signal and the information stored in advance by the storage means .

[0011]

According to the first substrate single-wafer detecting apparatus constructed as described above, the light emitting portion of the transmitted light type detecting means is provided with a polarizing filter so as to be linearly polarized parallel to the substrate, for example, the wafer surface. By making only the reflected light incident on the wafer, the reflection of light by the wafer is suppressed as much as possible, and the presence or absence of the wafer can be reliably detected based on the intensity of the transmitted light from the wafer to be detected. In other words, even when light from the light emitting unit is incident on a wafer surface other than the wafer to be detected, most of the light is transmitted as it is without being reflected, so that light is prevented from entering the light receiving unit. Thus, the wafer can be detected with high accuracy.

Further, by providing a polarizing filter in the light receiving section so that only light linearly polarized in parallel to the substrate, for example, the wafer surface, is received, reflected light (most of the reflected light is reflected on the wafer surface). Is partially polarized perpendicular to the wafer, and the intensity of the transmitted light from the wafer to be detected (most of the transmitted light is partially polarized parallel to the wafer surface) is used to detect the intensity of the wafer. Presence or absence can be reliably detected.
That is, even when the light from the light emitting unit is incident on a wafer surface other than the wafer to be detected, the light reflected on the wafer surface is blocked by the polarizing filter, so that the sneak of the light to the light receiving unit is suppressed and the light is reduced. The wafer can be detected with high accuracy.

Accordingly, by providing the polarizing filters in both the light emitting section and the light receiving section, the detection accuracy of the substrate can be further improved.

Next, according to the second substrate single-wafer detecting device configured as described above, the light-emitting portions of the transmitted light type detecting means individually emit light when no substrates, for example, wafers are arranged. The amount of received light detected by each of the light receiving sections is determined in advance, and the data is stored in the storage means, and the value of the corresponding data stored in the storage means is actually compared with the value of the wafer. By comparing the value of the received light amount at the time of detection with the value of the received light amount, it can be seen that erroneous detection due to sneak light has occurred. That is, the amount of received light detected in a state where no wafers are arranged is the maximum amount of received light of only direct light that is not affected by the sneak light, and the value of the maximum amount of received light is the value of the actual amount of received light. By exceeding, it is understood that sneak light is incident on the light receiving portion in addition to the direct light from the light emitting portion. This wraparound is a phenomenon that occurs remarkably when there is a wafer misalignment, particularly when there is a missing wafer (missing teeth), and thus the location of the missing wafer is detected by the above comparison. Then, when a wafer omission has occurred, it can be assumed that the sneak light also affects the light receiving portions on both sides of the occurrence location. Therefore,
By subtracting a constant value corresponding to the influence of the sneak light from the value of the received light amount detected by the adjacent light receiving units, the light reception amount of the two light receiving units is corrected, and thereby the presence or absence of the wafer due to the influence of the sneak light is corrected. Detection can be prevented.

Further, according to the third substrate single-wafer detecting device configured as described above, when the moving means relatively moves the substrate, for example, the wafer, and the detecting means, the light emitting part of the detecting means changes to the light receiving part. When the optical axis of the light changes due to the passage of the edge of the wafer, the change in the amount of light can be detected. The detected light quantity is compared with information stored in advance, and is taken in as information on the presence or absence of a wafer. Therefore, the transmittance is 10 without being affected by disturbance light.
The presence / absence or posture of a transparent wafer or the like close to 0% can be stably detected.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing a case where the first embodiment of the substrate single-wafer detecting apparatus of the present invention is applied to a wafer cleaning apparatus. FIG. 2 is a single-wafer detecting apparatus according to the first embodiment. FIG. 3 is a cross-sectional perspective view of main parts of FIG. 2, FIG. 4 is a cross-sectional view of main parts of FIG. 2, and FIG. 5 is a schematic configuration diagram of a single-wafer detecting apparatus of the first embodiment. I have.

A cleaning apparatus having a single-wafer detecting apparatus according to the present invention includes a cleaning tank 1 for storing a cleaning treatment liquid, and a substrate such as a semiconductor wafer 3 (hereinafter, referred to as a wafer) which is provided in the cleaning tank 1 so as to be able to come and go. ) Holding the wafer chuck 2a. The wafer chuck 2a is configured such that a pair of left and right holding portions 2f having two upper and lower holding rods 2c having a plurality of wafer holding grooves 2b provided at appropriate intervals in the longitudinal direction can be opened and closed. The plurality of wafers 3 held by the wafer chuck 2a are transferred above the cleaning tank 1 by the wafer transfer body 2d, then lowered and transferred to a wafer holding unit (not shown) in the processing tank 1. It is supposed to be.

The single-wafer detecting apparatus according to the present invention is provided with a pair of corrosion-resistant devices disposed on both sides of the wafer chuck 2a while being supported horizontally and in parallel with each other by brackets 2e provided upright on both sides of the wafer carrier 2d. A light-emitting unit (specifically, light-emitting element 7) and a light-receiving unit (specifically, light-receiving element 8) are arranged in a tube such as a quartz tube 5a that is a transparent tube. The light-emitting element 7 and the light-receiving element 8 are made of metal disposed longitudinally in a quartz tube 5a attached to a bracket 2e via an O-ring 5b, as shown in FIGS. Alternatively, it is buried in a through hole 5d provided at an appropriate interval in a holder 5c made of synthetic resin, and is connected to a printed circuit board 5e extending above or below the holder 5c by a lead wire 5f. ing. An O-ring 5g is provided at the open end of the quartz tube 5a opposite to the bracket 2e side.
, And an end cap 5h is attached thereto, and the connector 5 is connected to the bracket 2e via an O-ring 5i.
j and the printed board 5e are connected by a cable 5k.

The light-emitting elements 7 and the light-receiving elements 8 respectively disposed in the pair of quartz tubes 5a provided on both sides of the wafer chuck 2a are arranged and held by the wafer chuck 2a, and are arranged between the adjacent wafers 3. Are arranged alternately corresponding to the positions of the gaps 11. That is, as shown in FIG. 5, the light emitting elements 7 are arranged at every other gap 11 between the wafers 3, and the light receiving elements 8 are arranged at the gap positions between the wafers 3 where the light emitting elements 7 are not located. Are arranged to face each other. Further, as shown in FIG. 4, the single-wafer detecting apparatus according to this embodiment includes a sensor holder 5 on the light receiving element 8 side.
A polarizing filter 17 is attached to the front surface of the light-receiving element c, and the openings of all the through holes 5d in which the light receiving elements 8 are embedded are closed by the polarizing filter 17. The polarizing filter 17 is formed by interposing a polarizing film between transparent plastic sheets, and its transmission axis direction (the direction of vibration of the electric field vector) is aligned with the wafer surface of the wafer 3 arranged and held by the wafer chuck 2a. It is attached so as to be parallel with respect to it.

The light emitting element 7 arranged as described above is connected to a light emission control unit 12 for selectively switching the light emitting element, and the light receiving element 8 is a light beam corresponding to the switching operation of the light emitting element 7. The light receiving control unit 13 for detecting the system is connected. A central processing unit (CPU) 14 for comparing and calculating the signals of the light emission control unit 12 and the light reception control unit 13 and outputting a detection display signal is connected to the light emission control unit 12 and the light reception control unit 13. The CPU 14 sends a signal for switching the light emitting element 7 based on information stored in advance to the light emission control unit 12.
And receives a signal from the light emission control unit 12,
After comparing the stored information with the signal from the light receiving control unit 13, the presence / absence at each position of the wafers 3 arranged and held on the wafer chuck 2a, the display of the number of wafers, and the output signal of the wafer 3 are detected. You can do it.

Next, a description will be given of an operation mode of the single-wafer detection of the wafer 3 by the single-wafer detection apparatus of this embodiment with reference to FIG. Here, in order to make the operation easy to understand, a plurality of wafers 3 are arranged in the order of arrangement,..., Three light emitting elements 7 are A, B, and C, and three light receiving elements 8 are a, a, and c. I do.

First, when the light emission control section 12 is operated by the signal from the CPU 14 and the light emitting element 7 of A emits light,
The wafer 3 is detected by the light receiving element 8. The signal detected by the light receiving element 8 is transmitted from the light receiving control unit 13 to the CPU 14, and the CPU 14 compares the output signal to the light emission control unit 12 with the light receiving signal from the light receiving control unit 13, and Is detected, and the number "1" is counted. In this case, even if the light from the light emitting element 7 of A is reflected by the adjacent wafer 3 as shown by, for example, a two-dot chain line arrow L and sneak into the light receiving element 8 of A, the light after reflection is still Since the light is partially polarized perpendicular to the wafer surface, it is cut off by the polarization filter 17. Therefore, the presence or absence of the wafer 3 is reliably detected.

Next, when the second light emitting element 7 emits light in response to a signal from the CPU 14, the wafer 3 is detected by the light receiving element 8a, and the wafer 3 is detected by the light receiving element 8a. Then, the light receiving element 8 of A and B
The signal detected by the CPU 1 is transmitted from the light receiving control unit 13 to the CPU 1.
The output signal to the light emission control unit 12 and the light reception signal from the light reception control unit 13 are compared and processed by the CPU 14, and the presence or absence of the wafer 3 is detected. Be counted. Even in this case, even if the light from the light emitting element 7 of B is reflected on the wafer 3 (for example,) other than the wafer 3 to be detected and sneak into the light receiving element 8 of A and B, Since the wraparound light is blocked by the polarizing filter 17, the presence or absence of the wafer 3 is surely detected.

Next, when the third light emitting element 7 emits light in response to a signal from the CPU 14, the wafer 3 is detected by the light receiving element 8 and the wafer 3 is detected by the light receiving element 8 of c. Then, the light receiving elements 8 of A and C
The signal detected by the CPU 1 is transmitted from the light receiving control unit 13 to the CPU 1.
The CPU 14 compares the output signal to the light emission control unit 12 with the light reception signal from the light reception control unit 13 in the CPU 14 to detect the presence or absence of the wafer 3, and further reduces the number of wafers “3”. Be counted. Even in this case, even if the light from the light emitting element 7 of C is reflected on the wafer 3 other than the wafer 3 to be detected and wraps around the light receiving element 8 of A and C, the wraparound light is polarized. Since the wafer 3 is shut off by the filter 17, the presence or absence of the wafer 3 is reliably detected.

Hereinafter, similarly, the fourth and subsequent light emitting elements 7
And the presence or absence and the number of the plurality of wafers 3 can be detected. By providing the polarizing filter 17 on the light receiving element 8 side, when detecting a transparent or translucent wafer, malfunction due to sneak light generated by reflection on the wafer surface can be prevented. Can also be detected with high accuracy.

In the above embodiment, the case where the polarizing filter 17 is provided on the light receiving element 8 side has been described. However, the polarizing filter 17 is provided on the light emitting element 7 side instead of the light receiving element 8 side, and is parallel to the wafer surface. Alternatively, light that has been linearly polarized in advance may be emitted. In this case, since the reflection of light by the transparent or translucent wafer is suppressed as much as possible (most of the incident light passes through the wafer as it is), it is possible to prevent the light from entering the light receiving element 8 and detect the wafer with high accuracy. It can be performed. Therefore, the light emitting element 7 side and the light receiving element 8
By providing the polarization filters 17 on both sides, the detection accuracy can be further increased.

Second Embodiment FIG. 6 is a schematic block diagram of a single-wafer detecting apparatus according to a second embodiment of the present invention. FIG. 5 is the same as FIG.
However, in the single-wafer detection apparatus of the second embodiment, a member corresponding to the polarization filter 17 of the first embodiment is not provided. In other words, the single-wafer detection apparatus according to the second embodiment is not a hardware improvement but mainly a CPU.
14 enables highly accurate detection by the data processing.

In the sheet detecting apparatus according to the second embodiment, the CP
When no wafers 3 are arranged in the memory 14a (storage means) in the data area in U14, A,
When the light-emitting elements 7 emit light one by one in the order of B, C,..., The data (reference data ) of the amount of light received by the respective light-receiving elements 8 of A, A, C,. Is
Information} is stored, also, the memory 14b of the calculation region
The (storage means) stores the value of the amount of light received by each light receiving element 8 when the wafer 3 is actually detected and the value of the corresponding data stored in the memory 14a in the data area. In comparison, when the detected value of the actual amount of received light exceeds the value of the stored data, that is, it is affected by the sneak light.
The detected value of the actual amount of received light is
When the value exceeds the value, it also affects the light receiving elements located on both sides of the light receiving element that detected the amount of received light.
From the value of the light-receiving amount detected by the light receiving element, wraparound light
A program for performing a series of data processing for correcting the detection values of both light receiving elements by subtracting a constant value corresponding to the influence of the above is stored. That is, the CPU 14 performs various functions in the first embodiment (a function of detecting the presence or absence of each position of the wafer 3 via the light emission control unit 12 and the light reception control unit 13, display of the number of wafers, and detection of an abnormal arrangement of the wafer 3). Signal output function, etc.), and also functions as storage means for correction reference data and correction means for detected values.

The reference data stored in the memory 14a in the data area is, for example, when the output (light emission power) of the light emitting element 7 of A is 8 and the light receiving sensitivity of the light receiving element 8 of A is 10. The value of the amount of received light in the set of the light emitting element 7 and the light receiving element 8 of A and A is approximately 80 (= 8 × 10),
When the light receiving sensitivity of the light receiving element 8 of A is 7, the value of the amount of received light in the set of the light emitting element 7 and the light receiving element 8 of A and A is approximately 56 (= 8 × 7) . Other light emitting element 7
The value of the amount of received light in the set of the light receiving element 8 and the light receiving element 8 is also roughly estimated based on the capability value of each element.

The CPU 14 controls the light emission control unit 12 and the light reception control unit 13 to operate the light emitting element 7 and the light receiving element 8 individually, and determines the value of the received light amount in the state where the wafers 3 are arranged and By comparing the value of the amount of received light in each set of the light emitting element 7 and the light receiving element 8 obtained in advance for each corresponding pair of the light emitting element 7 and the light receiving element 8, light emission in which false detection due to sneak light occurs has occurred. A pair of the element 7 and the light receiving element 8 is detected, and it is determined that the wafer 3 located between the light emitting element 7 and the light receiving element 8 is missing. A value obtained by subtracting a constant value corresponding to the influence of the sneak light from the value of the received light amount detected at 8 is used as a detection value of both light receiving elements 8 to detect the wafer 3.

Here, the constant values (correction amounts) to be subtracted from the values of the amounts of received light detected by the light receiving elements 8 on both sides of the location where the wafer is missing are stored in the memory 14 of the data area.
The value of the corresponding data stored in a and the value of 1/2 of the value of the actual amount of received light with respect to the light receiving element 8 can be used. This means that when a wafer dropout occurs, the light reflected by the wafers 3 on both sides enters the light receiving elements 8 on both sides of the wafer dropout location.
This is because the amount of incident light is estimated to be about half the amount of light directly incident on the light receiving element 8 from the light emitting element 7. Therefore, for example, when the reference value of the amount of received light in the set of the light emitting element 7 of B and the light receiving element 8 of A is 70, the value of the actual amount of received light in this set is 140
Is detected, the CPU 14 determines that the wafer 3 is missing, and thereafter, from the values of the amounts of received light of A and C located on both sides of the light receiving element 8 of A, 35 ((140-
The values obtained by subtracting the respective values 70) / 2) are used as the detection values of the light receiving elements 8 of (a) and (c) to detect the wafer 3.
In this case, the value of the corresponding data stored in the memory 14a in the data area and the rate of increase of the value of the actual amount of received light with respect to the light receiving element 8 (the value of the actual amount of received light / reference value) are corrected. As the amount, a predetermined ratio (20 to 50%) may be subtracted from the value of the amount of received light located on both sides of the light receiving element 8 where the wafer omission is detected.

As described above, by correcting the detected value of the actual amount of received light using the value corresponding to the influence of the sneak light as a correction amount, erroneous detection of the presence or absence of a wafer due to the influence of the sneak light can be prevented. By performing data processing in the CPU 14, the wafer 3 can be reliably detected without being affected by the sneak light, so that the presence / absence and the number of wafers can be determined with high accuracy even for a quartz wafer or the like which is likely to sneak due to reflection. Can be detected.

As described above, when the light-emitting elements 7 emit light one by one, the values of the amounts of received light detected by the respective light-receiving elements 8 are used as reference data in advance by the CPU 14.
And the actual received light amount is corrected based on the corresponding reference data, so that the light emitting efficiency and light receiving efficiency of each light emitting element 7 and light receiving element 8 vary. Even in some cases, the presence or absence of a wafer can be stably detected.

Third Embodiment FIG. 7 is a schematic perspective view of a single-wafer detection apparatus according to a third embodiment of the present invention, and FIG. 8 is a schematic configuration diagram of the principle of a detection unit of the single-wafer detection apparatus.

The single-wafer detecting apparatus according to the third embodiment is a case in which the presence or absence or the posture is detected based on a change in the amount of light of the optical axis passing through the edge of the wafer. That is, based on a change in the amount of light when the optical axis of light passes through the edge of the wafer when the transmitted light detecting means including the light emitting unit and the light receiving unit and the wafer are relatively moved, the presence / absence or posture of the wafer is determined. Is detected.

In this case, the sheet detecting device is a sensor stay 15 which can be moved up and down by an elevating device 15 which is moving means.
a pair of quartz tubes 5 projecting horizontally and parallel from each other
The light emitting element 7 and the light receiving element 8 are alternately arranged between the first and second embodiments in the same manner as in the first and second embodiments. Thus, the wafers are arranged on both sides of a row of wafers (wafer row) arranged on a wafer boat 16 which can be moved up and down. The light emitting element 7 and the light receiving element 8 are connected to a host computer 19 via a control circuit 18 as a detecting means.
It is connected to the.

As shown in FIG. 8, the control circuit 18 selectively performs the switching operation of the light emitting element 7, and controls the light receiving element 8 to detect the light beam (optical axis) in response to the switching operation. A logic 18a, a bus 18b for transmitting and receiving a control signal and information on the amount of received light between the light emission / light reception control logic 18a, and the memory 1 of the second embodiment.
4a (storage means), information stored in advance in the memory 18c , that is, a state where the wafers 3 are not arranged at all.
When the light-emitting elements 7 emit light one by one in the state
Data on the amount of light received by each light receiving element 8 (reference
Processing unit (CPU) 18 d for comparing and calculating the received light amount and the detected amount of received light, and a host computer 19.
And an input / output unit (I / O) 18e for transferring data processed by the arithmetic processing unit 18d and a command signal from the photo computer 19. Since the received light amount data from the light emission / light reception control logic 18a is an analog signal, it is analog / digital (A
/ D) The signal is converted into a digital signal by the converter 18f and transmitted to the bus 18b.

In the single-wafer detecting apparatus according to the third embodiment, the sensor stay 15a is moved by the elevating device 15 or the wafer boat 16 or the sensor stay 15a and the wafer boat 1 are moved by moving means (not shown).
When the light source 6 moves relatively to the detection point of the wafer 3 by moving or passing the same, the optical axis of the light from the light emitting element 7 to the light receiving element 8 of the detection means of the switching means which is sequentially switched as in the first and second embodiments. Is changed by the passage of the edge of the wafer 3 (see FIG. 9), and the change in the light amount is detected by the control circuit 18. The received light amount data detected by the control circuit 18 is compared with information previously stored in a memory 18c in an arithmetic processing unit 18d, and when the detection level falls below a certain level, it is determined that a wafer is present and the detection is performed. The data is taken into the host computer 19 as information on the presence or absence of a wafer. The detection level can be continuously monitored based on a signal from the host computer 19.
After moving (or passing) the wafer 3 and / or the detecting means, the monitor is stopped, and data on the presence or absence of the wafer 3 is taken out. If the cycle time for the CPU to detect and determine all the wafers 3 is 50 msec. The width of scattering light from the light emitting element 7 to the light receiving element 8 at the wafer edge is 1 mm and the margin is doubled, the moving speed is 10 mm. / Sec.

As described above, by detecting the change in the optical axis of the light passing through the edge of the wafer 3, the presence or absence or posture of the transparent wafer or the like having a transmittance close to 100% can be stabilized without being affected by disturbance light. Can be detected.

The sheet detecting apparatus of the present invention configured as described above is used, for example, by being incorporated in a cleaning apparatus shown in FIG. As shown in FIG. 10, the cleaning processing apparatus includes a loading unit 21 that stores a wafer 3 that is an unprocessed object to be processed, a cleaning processing unit 22 that performs a cleaning process on the wafer 3,
The main part is constituted by the carry-out part 33 for accommodating the washed wafer 3.

The carry-in section 21 has a standby section 25 for a carrier 24 for accommodating the wafers 3, a loader section 26 for taking out the wafers 3 from the carrier 24, aligning the orientation flat, detecting the number of wafers 3, and the like. Carrier 24 to be carried in
And a carrier transport arm 27 for transferring the carrier 24 to the standby unit 25 and the carrier 24 between the standby unit 25 and the loader unit 26.

The cleaning section 22 includes a first chuck cleaning / drying processing chamber 20a, a first chemical processing chamber 20b, a first water cleaning processing chamber 20c, and a linear cleaning chamber 22a. A second washing processing chamber 20d, a second chemical processing chamber 20e, a third washing processing chamber 20f, a fourth washing processing chamber 20g, a second chuck cleaning / drying processing chamber 20h, and a wafer drying processing chamber 20i are arranged. In each of these cleaning processing chambers (hereinafter, simply referred to as processing chambers) 20a to 20i, processing tanks 29 are provided. Further, on the side of the cleaning section 22, a guide section 30 is provided along each of the processing chambers 20a to 20i. The guide section 30 is mounted on the guide section 30 and horizontally (X direction) and vertically (Z direction). A wafer transfer device 35 is provided as a wafer transfer means composed of three movable wafer transfer blocks 31. The wafer transfer block 11 is provided with a wafer chuck 32 for holding a plurality of wafers 3 arranged in rows at appropriate intervals. The wafers held by the wafer chuck 32 are transferred to the processing chambers 20a to 20i. It is supposed to be.
In each of the processing chambers 20a to 20i, with the wafer 3 held by the wafer chuck 32, the single-wafer detecting apparatus of the present invention operates as described above to detect the presence / absence of a plurality of wafers 3 and the number of wafers 3. Is done. When there is no abnormality, the wafer 3 is processed and transferred to the next step. Note that a carrier transport unit 33 that transports empty carriers and full carriers is provided above the cleaning processing unit 22.
A processing liquid / piping region 34 including a tank and a piping group for storing a processing liquid such as a chemical liquid is provided on the back side of the cleaning processing unit 22.

In the above embodiment, the case where the single-wafer detecting apparatus of the present invention is applied to a wafer cleaning apparatus has been described. However, it is not always necessary to provide a plurality of wafers standing and held on the wafer holding arm 2 or the wafer boat 16. It is needless to say that the present invention can be applied not only to the detection of the single wafer of the wafer 3 but also to the detection of the single wafer of the wafer stored in the wafer cassette, or to a process of arranging and transporting other wafers. Further, a plate-like body other than a wafer, for example, an LCD
The present invention can also be applied to single-sheet detection when a plurality of substrates, printed boards, and the like are arranged.

[0045]

As described above, according to the substrate single-wafer detecting apparatus of the present invention, the following excellent effects can be obtained.

1) According to the apparatus for detecting a single substrate on a substrate according to the first aspect of the present invention, a polarizing filter is provided on at least one of the plurality of light emitting units and the light receiving unit of the transmitted light type detecting means, so that the light receiving element by reflection or the like This prevents harmful light from entering the transparent substrate, and enables the presence or absence and the number of transparent or translucent substrates to be reliably detected.

According to the second aspect of the present invention, the detection value of the actual amount of received light is corrected by using the value corresponding to the influence of the sneak light as a correction amount, thereby obtaining the influence of the sneak light. This can prevent erroneous detection of the presence or absence of the substrate due to this. By performing data processing without making any hardware improvements, the substrate can be reliably detected without being affected by the sneaking light, and the presence and number of transparent or translucent substrates that are likely to sneak due to reflection. Can be detected with high accuracy.

According to the third aspect of the present invention, a change in the amount of light in which the optical axis of the light from the light-emitting portion to the light-receiving portion of the detecting means changes by passing through the edge of the substrate is detected. The detected light amount can be compared with information stored in advance and taken in as information on the presence or absence of the substrate, so that the presence or absence or posture of a transparent substrate or the like whose transmittance is close to 100% without being affected by disturbance light can be determined. It can be detected stably.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view when a first embodiment of a substrate single-wafer detecting apparatus of the present invention is applied to a wafer cleaning apparatus.

FIG. 2 is a cross-sectional view illustrating a main part of the single-wafer detecting apparatus according to the first embodiment.

FIG. 3 is a sectional perspective view showing a main part of FIG. 2;

FIG. 4 is a sectional view showing a main part of FIG. 2;

FIG. 5 is a schematic configuration diagram illustrating a main part of the single-wafer detection apparatus according to the first embodiment.

FIG. 6 is a schematic configuration diagram showing a main part of a single-wafer detecting apparatus according to a second embodiment of the present invention.

FIG. 7 is a schematic perspective view when a third embodiment of the substrate single-wafer detecting apparatus of the present invention is applied to a wafer cleaning apparatus.

FIG. 8 is a schematic configuration diagram illustrating a principle of a detection unit in a third embodiment.

FIG. 9 is a characteristic curve diagram showing a light amount change in the third embodiment.

FIG. 10 is a perspective view showing a cleaning apparatus provided with the single-wafer detecting apparatus of the present invention.

[Explanation of symbols]

Reference Signs List 3 wafer (substrate) 7 light emitting element (light emitting section) 8 light receiving element (light receiving section) 14 CPU (storage means, correction means) 14a memory 14b memory 15 elevating device (moving means) 17 polarizing filter 18 control circuit (detection means) 18c Memory (storage means) 19 Host computer

Claims (3)

(57) [Claims] An apparatus for detecting the presence, number, and arrangement of substrates arranged at appropriate intervals, wherein a plurality of light-emitting portions and light-receiving portions of a transmitted light detecting means are arranged on both sides of a substrate row. And a polarizing filter is provided on at least one of the light emitting unit and the light receiving unit. 2. In a single-wafer detecting apparatus for detecting presence, number, and arrangement of substrates arranged at appropriate intervals, a plurality of light emitting units and light receiving units are alternately arranged on both sides of a substrate row. And transmitted light detection means, and storage for previously storing data of the amount of received light detected by the respective light receiving sections when the light emitting sections are individually lit in a state where the substrates are not arranged at all. A light receiving unit located on both sides of a light receiving unit that detects the amount of received light when the amount of received light when the substrate is actually detected exceeds the value of the corresponding data stored in the storage unit. And a correcting means for subtracting a constant value from the value of the amount of received light detected by the unit. 3. A single-wafer detecting apparatus for detecting presence / absence, number and arrangement of substrates arranged at appropriate intervals, wherein a plurality of light emitting units and light receiving units are alternately arranged on both sides of a substrate row. Transmitted light detection means, and the light emission in a state where the substrate is not arranged at all.
Each of the above light-receiving sections is detected when the
Storage means for storing in advance the data of the amount of received light to be output
When the moving means for relatively moving the said substrate and the detection means, the light receiving unit when the end of the substrate by the moving means passes through the optical axis of the light to the light receiving portion from the light emitting portion of the detecting means It detects a change in the amount of light received by the detection signal and the upper
A single-wafer detection apparatus for a substrate, comprising: detection means for detecting the presence or absence of a substrate from information stored in advance by a storage means .