JPH07147316A - Detector - Google Patents

Abstract

PURPOSE:To surely detect a storage state of treatment target substrates in a compartment by providing a translucent projection plate above the compartment, an image pickup device above this projection plate, and a light emitter emitting light toward treatment target substrates in the compartment below an opening. CONSTITUTION:A carrier C storing every twenty-five pieces is mounted in the station in a mount stage 5. When a light emitting tube 47 is lighted, the shadow of each wafer W is projected on a projection plate 51. An image pickup device 52 is actuated in this state to pick up the shadow of each wafer W on the projection plate 51 and makes image processing and arithmetic processing for detection. In the case where the third of wafers W stored in the carrier C jumps the slot to have its right side unstored in the slot of the carrier C, only a detection point R3 can not be detected with the result that a signal 'nothing' is outputted. Therefore, it is identified that the third wafer W jumps the slot.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection device for detecting the storage state of substrates to be processed stored in a storage body.

[0002]

2. Description of the Related Art An example of manufacturing a semiconductor wafer (hereinafter referred to as a "wafer") having a semiconductor device such as an LSI formed on the surface thereof will be described as an example. In a state of being stored in a storage body called a carrier that is aligned and stored in a state, the sheet is conveyed to a processing device that performs various types of processing and subjected to predetermined processing.

This type of carrier has a substantially box-like shape as a whole with an open upper surface, so that the wafers are vertically aligned and held in slots (grooves) formed facing each other in the carrier. Further, at the bottom of the carrier, there is provided an opening having a length extending over all the accommodated wafers, which is used for, for example, exchanging with a wafer chuck and alignment of an orientation flat (orientation flat). .

If each wafer is not properly stored in the slot in the carrier, there is a possibility that the wafers in the carrier are collectively processed. For example, when a wafer is delivered obliquely to a slot such as a jump slot, or when the edges of two wafers are delivered in one slot, a carrier such as a wafer chuck is used to hold the carrier. The wafers inside cannot be held together, and the wafers may be damaged. Therefore, it is necessary to detect in advance whether each wafer in the carrier is correctly stored in the corresponding slot.

In this regard, conventionally, such a detection is performed by scanning the upper end portion of the aligned wafer from above the carrier by a proper optical reading device in the carry-in portion of the processing apparatus. Was doing.

[0006]

However, according to the method as described above, first, the device configuration becomes extremely complicated,
Moreover, there is a problem in the design of the processing device to be adopted, such that the scan space of the optical reading device must be provided in the carry-in section. In addition, particles may be generated during scanning, and thus it cannot be used in a processing apparatus that needs to maintain a clean atmosphere.

The present invention has been made in view of the above points, and can reliably detect the storage state of a substrate to be processed in a storage body with a simple configuration, facilitate the subsequent arithmetic processing, and can further process the substrate to be processed in the storage body. It is an object of the present invention to solve the above-mentioned problems by providing a detection device capable of simultaneously counting the number of sheets.

[0008]

In order to achieve the above object, according to the present invention, an opening is formed in the bottom and at least one substrate to be processed is housed in a predetermined vertical state. A device for detecting a storage state of the substrate to be processed in a storage body, wherein a translucent projection plate is provided above the storage body, and the projection plate on the projection plate is provided above the projection plate. An image pickup device for picking up an image is provided, and a light emitting device that emits light toward the substrate to be processed in the housing is
A detection device is provided which is provided below the opening.

[Action]

According to the present invention, the light emitted from the light emitting device projects the shadow of each substrate to be processed in the housing on the projection plate, and the shadow of each substrate to be processed is further imaged by the image pickup device. At this time, for example, if there is a jump slot, the substrate to be processed is in an oblique state when viewed from above, and therefore the shadow of the edge of the substrate to be processed, which should originally be at the position corresponding to each slot, exists at that position. Disappear.
Therefore, such a jump slot can be detected by appropriately performing image processing on the state of the projection plate imaged by the imaging device. In such cases,
Since it is determined by the presence or absence of a shadow at a predetermined position, the process is performed under an image with clear contrast, and accurate detection can be performed by the binarization process.

As for counting the number of substrates to be processed housed in the housing, the number of shadows of each substrate to be processed projected on such a projection plate may be counted by appropriate arithmetic processing. , It is possible to do this easily and accurately.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. This embodiment is an example used in a semiconductor wafer (hereinafter referred to as "wafer") cleaning apparatus. To explain the whole, as shown in FIG. 1, the cleaning apparatus 1 is roughly classified into a carrying-in section 2 for loading a wafer before cleaning processing in carrier C units, and a cleaning processing section for performing various cleaning processing of wafers. 3 and a carry-out section 4 for taking out the wafer after the cleaning process in units of carrier C,
It is composed of a total of three zones.

Into the carrying-in part 2, a carrier 5 for carrying a predetermined number, for example, 25, of uncleaned wafers C, when carrying the carrier C, and a carrier 5 mounted thereon are mounted. A transfer device 7 for transferring C to the alignment section 6 is provided. Further, the cleaning processing section 3 has three transfer devices 11, 1 on the front side (front side in FIG. 1).
2 and 13 are arranged, and each of these transport devices 11 and 1
Wafer chucks 14 and 15 respectively corresponding to 2 and 13;
16 are provided. In addition, also in the carry-out section 4,
A mounting table 8 having substantially the same configuration as the mounting table 5, an alignment section (not shown) having the same configuration as the alignment section 6, and a transfer device (not shown) having the same configuration as the transfer device 7 are provided. Has been.

In the cleaning processing section 3, a chuck cleaning / drying processing tank 21 for cleaning and drying the wafer chuck 14 of the transfer device 11 in order from the mounting table 5 side, organic contaminants on the wafer surface, metal impurities, Chemical solution cleaning processing tank 22 for cleaning impurities such as particles with a chemical solution, two water cleaning cleaning tanks 23, 24 for cleaning wafers cleaned in the chemical solution cleaning processing tank 22 with pure water, and the chemical solution cleaning processing tank 22, a chemical solution cleaning treatment tank 25 for performing cleaning treatment with a chemical solution different from the chemical solution in 22, and the chemical solution cleaning treatment tank 2
Two water washing / cleaning treatment tanks 26, 27 for washing the wafer washed in step 5 with pure water, a chuck washing / drying treatment tank 28 for washing and drying the wafer chuck 16 of the transfer device 13, and each of the above treatment tanks. A drying treatment tank 29 for vapor-drying the wafer from which impurities have been removed by the cleaning treatment in (1) is vapor-deposited with, for example, IPA (isopropyl alcohol) or the like.

The detecting apparatus according to the present embodiment is provided in the front carry-in section 2. First, the structure of the mounting table 5 installed in the carry-in section 2 is shown in FIGS. To explain based on this, on the stage 31 on the upper surface of the mounting table 5, stations 32, 33, 34 having substantially rectangular openings having mounting pieces at the four corners so that the bottom of the carrier C can be mounted.
Are provided in order from the front side, and between the stations 32, 33 and between the stations 33, 34, passage portions 35, 36 each having an opening narrower than the stations 32, 33, 34 are formed. Are formed.

Further, each of these stations 32, 33, 3
Near each corner of 4 is provided a locking member 37 that is substantially L-shaped in a plane and serves as a positioning for mounting the carrier C and locks the corner.

On the other hand, inside the mounting table 5, a moving mechanism 41 as shown in FIGS. 2 and 3 is provided. The moving mechanism 41 includes a mounting member 42 which is located on the upper surface and directly mounts the carrier C, and the mounting member 42 in the vertical direction (Z
(Direction), and a base 45 that supports the lift unit 43 and moves on the Y stage 44 in the Y direction.

A transparent plate 46 made of, for example, acrylic is provided on the upper surface of the mounting member 42, and an appropriate number of arc tubes 47 for creating a surface light source are provided in a space below the transparent plate 46. Light is emitted from directly under the ₂₅ wafers W _{1 to} W ₂₅ accommodated in the carrier C through the opening 48 on the lower surface of the carrier C placed on the transparent plate 46. In this case, since it is a surface light source, it is possible to clearly project the shadow of the wafer in the carrier C.

Above the station 32,
For example, a projection plate 51 made of white translucent acrylic is suspended from the top plate of the carry-in section 2 so as to be horizontal and parallel to the transparent plate 46 of the moving mechanism 41.
In such a case, it may be provided on the side plate of the carry-in section 2 via an appropriate support so that it is located above the station 32, for example, without being suspended from the top plate.

Above the projection plate 51, for example, a CCD (Char
An image pickup device 52 utilizing a ge-Coupled-Device) is arranged. The image pickup device 52 may be hung from the top plate of the carry-in section 2 or may be provided on the side plate of the carry-in section 2 via an appropriate support. The image signal from the image pickup device 52 is input to an appropriate arithmetic processing device (not shown) and subjected to detection processing.

Further, inside the mounting table 5, a device (not shown) for aligning the orientation flat of the wafer W in the carrier C is provided.
Carrier C set in the above stations 33 and 34
It is configured to do this for the wafer within.
A known technique can be used for a device for performing such orientation flat alignment. Of course, the device for performing the orientation flat alignment may be provided in the alignment unit 6 described later.

The transfer device 7 located behind the mounting table 5 is
A pair of arms 61 and 62 configured to be able to approach and separate from each other
And a lifter 6 that horizontally supports the arms 61 and 62.
3, a Z base 64 for moving the lifter 63 in the vertical direction (Z direction), and an X base 65 for moving the Z base 64 itself in the longitudinal direction (X direction) of the cleaning processing apparatus. As shown in FIG. 2, while holding the upper side edges of the carrier C on the arms 61 and 62, the carrier C is clamped by the arms 61 and 62, It is configured so that it can be transferred to a predetermined position of the projecting and aligning section 6.

As shown in FIG. 2, a holder 73 fixed to an up-and-down support column 72 projecting from an opening of the substrate 71 and fixed to another vertically opening of the substrate 71 in the aligning section 6. A holder 75 fixed on an elevating post 74 that projects and is movable to the side of the elevating post 72 and movable up and down,
Each of them is provided in series in the Y direction. In the figure,
The lift columns 72 and 74 are in a raised state (so-called push-up state).

Each of the holders 73 and 75 has a shape which can pass through the lower opening of the carrier C, and the lower end peripheral portions of the wafer W are inserted into the upper surfaces of the holders 73 and 75, respectively. A predetermined number of, for example, 25 holding grooves 76 are formed. In the vicinity of the opening corners, locking members 77 for locking the corners of the lower end of the carrier C are provided at four locations.

Elevating columns 72, 7 on the substrate 71
4, a light emitting member 83 and a light receiving member 84 of the optical sensor are arranged to face each other via support columns 81 and 82, and detection light from the light emitting member 83, for example, laser light is received by the light receiving member. It is configured to be received by 84.

The wafers W held by the holding sections 73 and 75 are collectively held by the wafer chuck 14 of the above-described transfer device 11 and transferred to a predetermined chemical cleaning tank 22. Is configured.

The cleaning apparatus 1 in which this embodiment is used is constructed as described above. Next, its operation will be described. First, the carrier C containing 25 unprocessed wafers W each is transferred by a transfer robot (see FIG. (Not shown), as shown in FIG. 1, it is mounted on the station 32 of the mounting table 5. Then, the moving mechanism 41 is positioned below the station 32 to light the arc tube 47. Then, on the projection plate 51, the shadow of each wafer W stored in the carrier C is projected on the projection plate 51. In this state, the image pickup device 52 is operated to pick up the shadow of each wafer W on the projection plate 51, and image processing and arithmetic processing for detection are performed.

The detection process is performed as follows, for example. First, as shown in FIG. 4, detection points L and R in an image are preset. The detection point L is for detection on the left side of the image, and the detection point R is for detection on the right side of the image. In each case, L _{1 to} L ₂₅ and R _{1 to} R ₂₅ are set corresponding to the number of slots in the carrier C, respectively.

The respective detection points L and R are set on the same X coordinate axis so as to correspond to each other. Further, the intervals on the Y coordinate axis of the respective detection points L _{1 to} L ₂₅ and R _{1 to} R ₂₅ may be equal intervals, and the angle of view of the lens used in the imaging device 52, the lens and the projection plate. The interval may be appropriately corrected based on the distance to 51 and the slot interval in the carrier C. Further, the positions of these detection points L and R on the Y coordinate axis do not have to be fixed, and may be automatically determined under the above-mentioned interval, for example, by the position of L ₁ .

Further, each of the detection points L _{1 to} L ₂₅ , R ₁ to
In R ₂₅ , the program is configured to detect the presence or absence of a shadow and output a binary value signal based on the presence or absence of the shadow, for example, a “present” or “absent” signal.

Then, for example, 2 provided in the carrier C
When all the ₂₅ wafers W _{1 to} W ₂₅ are correctly stored in the five slots, the shadow in the state as shown in FIG. 5 is projected on the projection plate 51. If the first detection points L ₁ and R ₁ are set so as to be located at both ends of the shadow WS ₁ of the wafer W ₁ , each of the detection points L ₁ to
For L ₂₅ and R _{1 to} R _{25, it} is confirmed that the shadows WS _{1 to} WS ₂₅ of the wafer are present, and all the signals “present” are output. Therefore, it can be detected that the wafers W in the carrier C are all properly aligned and held.

Further, by counting the output signal of "Yes", it can be detected at the same time that 25 wafers are stored in the carrier C.

However, among the wafers W accommodated in the carrier C, for example, when the third wafer W ₃ causes a jump slot and the right side thereof is not accommodated in the slot in the carrier C, FIG. The image as shown in FIG. 2 is projected on the projection plate 51. At this time, only the detection point R ₃ cannot detect the shadow, and a “none” signal is output. Therefore, the carrier C
It can be confirmed that the third wafer in the table has a jump slot.

In this case, since the detection is performed based on the sharp shadow of the contrast projected on the projection plate 51, the lens used for the image pickup device 52 can be a wide-angle lens having a large angle of view. It is possible to set the image pickup device 52 close to the projection plate 51.

If the jump slot is detected in this way, for example, by displaying it appropriately by a warning means, or by displaying it externally, and at the same time, stopping the movement by the moving mechanism 41 and the orientation flat alignment, the wafer It is possible to prevent damage to the product.

Since the moving mechanism 41 is constructed so as to be able to move up and down by the elevating part 43, the carrier C placed on it is moved.
Can be raised to approach the projection plate 51, and in such a case, a clear shadow of the wafer W is projected on the projection plate 51. Therefore, it is possible to perform detection with extremely high accuracy. Of course, the projection plate 51 side may be lowered.

If it is confirmed that the wafer is correctly stored in the carrier through the above detection process, the first carrier C ₁ is moved to the station 34 by the moving mechanism 41, and the next carrier C ₂ is moved. Is mounted on the station 32 of the mounting table 5 and, after undergoing a similar detection process, the second carrier C ₂ is moved to the station 33.

After the predetermined orientation flat alignment is completed for the wafers in the _two carriers C ₁ and C ₂ , these carriers C ₁ and C ₂ are moved to the arms 61 and 62 of the above-mentioned transfer device 7.
Are clamped at the same time, and are moved to a predetermined position defined by a locking member 77 provided on the substrate 71 of the above-mentioned alignment section 6 and placed there.

[0038] Then turn the holder 73, 75 raised by lifting columns 72, 74, through the opening 48 of the carrier C _1, C ₂ bottom, only a wafer housed in the carrier C _1, the C ₂ An operation is performed in which the lower ends of the wafers are pushed up and held in the holding grooves 76 of the holders 73 and 75, and the respective wafers are directly taken out above the carriers C ₁ and C ₂ .

At this time, for example, when a jump slot is generated due to the orientation flat alignment performed in the previous step and the wafers in the carriers C ₁ and C ₂ are not correctly held in the holding groove 76, this alignment portion is formed. 6 is detected by the light emitting member 83 and the light receiving member 84 of the optical sensor described above.

That is, as shown in FIG. 7, for example, when the wafer W ₀ has a jump slot, the upper end thereof is located higher than the other wafers W. Therefore, it is preset so that the optical axes between the light emitting members 83 and the light receiving members 84 are located slightly above the correctly accommodated wafers W at positions where the holders 73 and 75 are raised to some extent. And if the wafer W ₀ as described above
If there is a jump slot, the wafer W ₀ will block the detection light, as shown in FIG.
As a result, the light receiving member 84 cannot receive light. Therefore, it can be confirmed that there is a jump slot.

In this case, since the holders 73 and 75 are not a conventional two-piece type that is divided into left and right but a single member, the total length of the groove is long and the holder is in an oblique state. It is possible to refuse the delivery of the wafer into the holding groove 76 and surely make this wafer pop out higher than other normal wafers, which is a highly reliable detection.

As described above, according to the cleaning apparatus 1 described above, the jump slot of the wafer in the carrier C can be detected at the stage of being carried into the carry-in section 2, and after the orientation flat alignment is completed, the carrying apparatus is carried out. 11 wafer chucks 1
The jump slot can be detected even immediately before the batch-holding of the wafers by 4. Therefore, it is possible to prevent wafer damage, device accident, etc. due to the jump slot.

Although the above embodiment is an example applied to a transfer device in a wafer cleaning device, the present invention is not limited to this, and various processes are carried in while the non-processed substrate is stored in a storage body such as a carrier. It is also applicable to devices.

[0044]

According to the present invention, if there is an abnormality such as a jump slot in the storage state of the substrate to be processed stored in the storage body, it can be immediately detected.
At the same time, it is possible to count the number of substrates to be processed contained in the container. Further, since such detection and counting can be performed by processing the image of the shadow of the object to be processed projected on the projection plate, it is extremely accurate and its reliability is high.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a cleaning device in which an embodiment of the present invention is used.

FIG. 2 is a perspective view of an essential part of an embodiment of the present invention.

FIG. 3 is an explanatory view schematically showing a vertical cross section of an example of the present invention.

FIG. 4 is a diagram showing an operation of the embodiment of the present invention, and an explanatory diagram showing a state of arrangement of detection points on an image.

FIG. 5 is a diagram showing an operation of the embodiment of the present invention, and an explanatory diagram showing a state when all the wafers are normally stored in the carrier.

FIG. 6 is a diagram showing the operation of the embodiment of the present invention, and is an explanatory diagram showing a state when the third wafer raises a jump slot.

FIG. 7 is a perspective view of an optical sensor provided in an alignment unit of a cleaning device in which an embodiment of the present invention is used.

[Explanation of symbols]

1 cleaning device 2 carrying unit 5 mounting table 41 moving mechanism 42 mount member 47 arc tube 48 opening 51 projection plate 52 imaging device C Carrier _{L 1 ~L 25, R 1 ~R} 25 detection point W wafer WS ₁ to WS ₂₅ Shadow

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinji Tadakuma 4175 Nishishinmachi, Tosu City, Saga Prefecture 41 Electron Kyushu Co., Ltd. Saga Works

Claims (1)

[Claims] 1. A storage body, which has an opening at the bottom and is configured to store at least one substrate to be processed therein in a predetermined vertical state, for detecting the housed state of the substrate to be processed. An apparatus, wherein a translucent projection plate is provided above the storage body, and an image pickup device for picking up an image on the projection plate is further provided above the projection plate. A detecting device, characterized in that a light emitting device for emitting light toward is provided below the opening.