JP7276090B2 - Inspection method, silicon wafer manufacturing method and inspection device - Google Patents

Description

The present invention relates to an inspection method for inspecting a plurality of wafers housed in a container, a silicon wafer manufacturing method, and an inspection apparatus.

In general, wafers such as silicon wafers are put into a dedicated shipping container after undergoing an inspection for detecting foreign matter and pattern defects. At this time, the plurality of wafers are stored in the shipping container in an aligned state.

Next, a final inspection such as confirmation of the number of wafers in the container in which the wafers are stored and deviation of the wafers is performed. As a related technique, Patent Literature 1 describes an inspection apparatus capable of inspecting the cleanliness of a container before wafers are stored therein.

Further, as a technology for automatically inspecting the position of a wafer using a sensor, Patent Document 2 discloses that a distance sensor or the like is used to store a wafer in a storage stage provided in a transport container between processes in a factory. An apparatus is disclosed that can inspect a wafer for misalignment.

JP 2012-99691 A Japanese Patent Application Laid-Open No. 2001-210699

By the way, the container that stores the wafer may differ depending on the shipping destination. The shape of the container and the material forming the container vary. For example, if there is unevenness in a part of the container, problems such as misalignment of some wafers may not be detected.
On the other hand, the inspection apparatus described in Patent Literature 1 can clean containers of various shapes, but it does not have the function of checking the number of wafers in the container and inspecting the misalignment of the wafers. Further, the inspection apparatus described in Patent Document 2 does not inspect wafers stored in a shipping container, but inspects wafers stored in an immovable storage chamber, and is compatible with containers of various shapes. It is not intended to

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inspection method, a silicon wafer manufacturing method, and an inspection apparatus capable of inspecting the positions of a plurality of wafers in a container regardless of the shape of the container.

The inspection method of the present invention is a method for inspecting a plurality of wafers which are stored in a container made of a transparent or semi-transparent material, arranged parallel to each other and at equal intervals so that the center axes of the wafers match. A first photographing step of photographing the entirety of the plurality of wafers through the container from a direction parallel to the main surface of the wafer; a second photographing step of photographing the wafers, and an inspection step of inspecting the positions of the plurality of wafers in the container using the images photographed in the first photographing step and the second photographing step; , An inspection method characterized by having

In the inspection method, in the inspection step, the number of the plurality of wafers is counted using the images captured in the first imaging step and the second imaging step, and misalignment of the plurality of wafers is inspected. may

In the inspection method, in the first photographing step, an infrared camera may be used to photograph, and infrared rays may be irradiated through the container from the opposite side of the infrared camera toward the infrared camera.

The silicon wafer manufacturing method of the present invention includes inspecting the plurality of wafers in the container using any of the inspection methods described above.

The inspection apparatus of the present invention is an inspection apparatus for a plurality of wafers arranged parallel to each other and at equal intervals so that their central axes are aligned in a container made of a transparent or translucent material. A main camera that photographs the entirety of the plurality of wafers through the container from a direction parallel to the principal surfaces of the wafers; and an analysis device for inspecting the positions of the plurality of wafers in the container using the images captured by the main camera and the sub cameras.

In the above inspection apparatus, the analysis device has a function of counting the number of the plurality of wafers using images captured by the main camera and the sub camera, and inspecting positional deviation of the plurality of wafers. you can

In the above inspection apparatus, the main camera may be an infrared camera, and the inspection apparatus may have an infrared illuminator that irradiates infrared rays toward the main camera from the opposite side of the main camera through the container.

According to the present invention, even if a part of the container has unevenness and some of the plurality of wafers cannot be imaged by the main camera due to the unevenness, the wafers that cannot be imaged by the main camera can be imaged by the sub camera. Multiple wafer positions within the can be inspected.

1 is an exploded perspective view of a first container according to an embodiment of the invention; FIG. Fig. 2 is an exploded perspective view of a second container according to an embodiment of the present invention; FIG. 4 is a cross-sectional view of the lid of the second container according to the embodiment of the present invention; 1 is a cross-sectional view of an inspection device according to an embodiment of the present invention; FIG. 1 is a system configuration diagram of an inspection apparatus according to an embodiment of the present invention; FIG. FIG. 10 is a cross-sectional view of the main parts of the second container containing the wafers, and is a view for explaining the positional relationship with the camera. It is a flow chart explaining an inspection method of an embodiment of the present invention. It is an example of an image captured by a main camera. It is an example of an image captured by a sub-camera. It is a flow chart explaining a manufacturing method of a silicon wafer of an embodiment of the present invention.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
The inspection apparatus of the present invention relates to shipping inspection of wafers such as silicon wafers manufactured using the Czochralski method, for example. It is an apparatus for inspecting a plurality of wafers that have been processed.
Each wafer is disk-shaped and is housed in a container parallel to each other and aligned at regular intervals so that their central axes are aligned.
Here, the wafer is not limited to a silicon wafer, and may be a wafer such as a germanium wafer. That is, the inspection apparatus of the present invention can inspect any wafer, which is a disk-shaped plate obtained by slicing a cylindrical ingot thinly, for example.

A container containing a plurality of wafers is made of a transparent or translucent material. The container is formed so that the peripheral edges of the plurality of wafers can be visually recognized from the outside. Since the container is formed so that the peripheral edges of the wafers can be visually recognized from the outside, it is possible to inspect the number of wafers and the misalignment of a plurality of wafers (inconsistency in the spacing between adjacent wafers) using an inspection device. .

Here, the shape of the container may differ depending on the shipping destination.
For example, one container is made of translucent plastic. If the container is made of translucent plastic, the visibility of the contained wafers is poor.
Other containers may have projections formed on the top. The protrusions are used, for example, for aligning the containers when the containers are stacked vertically. If protrusions are formed on the upper portion of the container, the protrusions impair the visibility of specific wafers.

The inspection apparatus of the present invention makes it possible to inspect the positions of a plurality of wafers housed in a container regardless of the material and shape of the container.

Here, two containers (first container 50A and second container 50B) having different shapes among the containers 50 assumed to be used will be described in detail.
First, the first container 50A will be described with reference to FIG. FIG. 1 is an exploded perspective view of the first container 50A.
As shown in FIG. 1, the first container 50A includes a cassette 56 formed with alignment slots 57 for aligning and storing a plurality of wafers (not shown), a container body 51 for storing the cassette 56, and a container body 51 for storing the wafers. It has a lid 53 that can be attached to and detached from the cassette 51 and a wafer holder 58 that holds and buffers the wafers in the cassette 56 .
The container main body 51 and the lid 53 are made of translucent plastic. Translucent is eg opalescent, textured, frosted, and objects on the other side of the translucent plastic appear cloudy.

By being held in the alignment slots 57 of the cassette 56, the stored wafers are arranged parallel to each other, the center axes of the wafers are aligned, and the center axes of the wafers are horizontal (the bottom of the container 50 and the bottom of the container 50). parallel). In other words, the alignment slots 57 are formed so that the plurality of wafers housed in the container are aligned parallel to each other and at regular intervals so that their central axes are aligned.

The lid 53 is a member that seals the top of the container body 51 .
The lid body 53 has a substantially rectangular upper surface portion 54 and side surface portions 55 protruding from the edges of the upper surface portion 54 .
The lid 53 and the container main body 51 are formed so that the side surface portion 55 of the lid 53 and the peripheral edge portion of the upper portion of the container main body 51 are engaged. The upper surface portion 54 of the first container 50A is formed flat.

Next, the second container 50B will be described with reference to FIGS. 2 and 3. FIG. In the following description, differences from the first container 50A will be described. FIG. 2 is an exploded perspective view of the second container 50B.
In the first container 50A, the container main body 51 and the lid 53 are made of translucent plastic. Made of plastic.
As shown in FIG. 2, the upper surface portion 54B of the lid 53B has two protrusions 59 formed on the upper surface of the upper surface portion 54B. Each protrusion 59 extends in a direction parallel to the stored wafers (a direction orthogonal to the arrangement direction of the wafers) and is formed parallel to each other.

As shown in FIG. 3, the upper surface portion 54B and the projection 59 are integrally formed. The cross-sectional shape of the protrusion 59 is trapezoidal.

The first container 50A and the second container 50B are made of polyolefin resin such as polyethylene (PE) and polypropylene (PP), polycarbonate (PC), polybutylene terephthalate (PBT) and other synthetic resins represented by various elastomers. can be obtained by injection molding the resin material into the desired shape of each member.
Note that the configuration of the container 50 is not limited to the configuration described above, as long as a plurality of wafers can be aligned in parallel with each other at equal intervals so that their central axes are aligned, and can be changed as appropriate. can be done.

Next, the inspection device 1 will be described. As shown in FIG. 4 , the inspection apparatus 1 includes a housing 2 , a container conveying device 3 that conveys the container 50 , an imaging device 4 that photographs the container 50 , and a control device 5 .
The inspection apparatus 1 automatically takes the container 50 into the housing 2, photographs a plurality of wafers W in the container 50 using the cameras 12 and 13 (image pickup device 4), and analyzes the images obtained by the photographing. By doing so, it has a function of inspecting the position of the wafer W.

The housing 2 is composed of a frame 7 and a cover 8 that covers the frame 7, and accommodates the imaging device 4, the control device 5, and the like that constitute the inspection apparatus 1. As shown in FIG. The housing 2 has a box shape, and the inside of the housing 2 is a dark room with a cover 8 covering the whole. The housing 2 has an opening 9 for transporting a container 50 containing a plurality of wafers W into the housing 2 .

The container transporting device 3 transports the container 50 placed at the placement position P0 outside the housing 2 to the inside of the housing 2, or transports the container 50 that has been photographed inside the housing 2 to the housing 2. It is a device for transporting to the outside of the
The container conveying device 3 has a belt conveyor 10 that conveys the container 50 inside and outside the housing 2 through the opening 9 of the housing 2, and a shutter 11 that opens and closes the opening 9 of the housing 2. there is By closing the shutter 11, the inside of the housing 2 can be made into a dark room.
The belt conveyor 10 has multiple belts. The multiple belts are spaced apart from each other at predetermined intervals in a direction orthogonal to the plane of FIG.

The container transport device 3 can move the container 50 between the placement position P0, the first imaging position P1, and the second imaging position P2. The placement position P0 is outside the housing 2 and is a position where the operator places the container 50 to be inspected.
The first imaging position P1 and the second imaging position P2 are inside the housing. The container transport device 3 is electrically connected to the control device 5 .

The photographing device 4 is a device for photographing the container 50 (a plurality of wafers W) moved inside the housing 2 .
The photographing device 4 includes a main camera 12 for photographing the container 50 arranged at the first photographing position P1 and a sub-camera 13 for photographing the container 50 arranged at the second photographing position P2. and an infrared illuminator 14 that irradiates infrared rays toward the main camera 12 from the opposite side of the main camera 12. - 特許庁The wavelength of the infrared rays emitted from the infrared illumination 14 is preferably about 700 nm to 1 mm, which is the wavelength that passes through the container 50 .

The main camera 12 and sub camera 13 are digital cameras using infrared sensors. That is, the main camera 12 and the sub camera 13 have a function of receiving infrared rays and converting them into electric signals.

The main camera 12 is a camera that captures the entirety of the plurality of wafers W inside the container 50 from above. The main camera 12 photographs a plurality of wafers W through the lid 53 of the container 50 . The main camera 12 photographs the entirety of the plurality of wafers W from a direction parallel to the main surfaces of the wafers W. As shown in FIG. The distance between the main camera 12 and the container 50 is set so that the main camera 12 can photograph the entire container 50 . Images captured by the main camera 12 are transmitted to the control device 5 .

The infrared illuminator 14 irradiates the container 50 placed at the first photographing position P1 from below the main camera 12 and below the belt conveyor 10 with infrared rays. Infrared rays pass between the belts that make up the belt conveyor 10 and reach the main camera 12 via the container 50 .

The sub camera 13 photographs the wafers W in the container 50 through the container 50 from a direction different from that of the main camera 12, and the main camera 12 is a camera for photographing a specific wafer Ws (see FIG. 6) that poses a problem in photographing. be. The sub-camera 13 photographs the wafer W from a direction inclined with respect to the direction parallel to the main surface of the wafer W.
Specifically, the sub-camera 13 preferably has an optical axis inclined from 40° to 80°, more preferably from 50° to 70° tilted.

The inspection device 1 has a plurality of contact sensors (not shown) for discriminating the container 50 . The contact sensor is provided at the placement position P0.

Next, the control device 5 of the inspection device 1 will be described.
As shown in FIG. 5, the control device 5 has a device control section 16 that controls the container conveying device 3 and the photographing device 4, and an analysis section 17 that analyzes the photographed image.

The device control unit 16 is a device that is electrically connected to the cameras 12 and 13 and the infrared illumination 14 that constitute the photographing device 4, and the belt conveyor 10 and the shutter 11 that constitute the container conveying device 3, and controls them. .

The analysis unit 17 has an analysis processing unit 18 (analysis device) that performs analysis processing, and an output unit 19 (display) that outputs the results obtained by the analysis processing unit 18 . The device control unit 16 and the analysis processing unit 18 are electrically connected. Inspection conditions are transmitted from the analysis processing unit 18 to the device control unit 16 .

The analysis processing unit 18 has a function of determining the type of the container 50 based on ON/OFF of the contact sensor.
The analysis processing unit 18 analyzes the images captured by the cameras 12 and 13 according to an image processing program. The image processing program has a function of counting the number of wafers W from the photographed image.
Specifically, the image processing program acquires lot information from the label attached to the container 50, and the number of wafers W based on the lot information matches the number of wafers W counted from the photographed image. determine whether or not
Lot information may be stored in a storage device or may be available via a computer network.
The image processing program also has a function of inspecting the positional deviation of the wafer W from the photographed image.

The image processing program also has a function of judging whether or not there is a problem with the spacing between a specific wafer Ws and the wafers adjacent to the specific wafer Ws, based on the images captured by the sub-camera 13 .

Next, arrangement setting of the sub-camera 13 will be described.
FIG. 6 is a cross-sectional view of the essential parts of the second container 50B containing the wafers W, and is a view for explaining the positional relationship with the cameras 12 and 13. As shown in FIG.
As shown in FIG. 6, when using the second container 50B, that is, when using a container having a protrusion 59 (step) on the lid 53, when the main camera 12 photographs from above, a specific wafer The projection 59 makes it difficult for Ws to be reflected.

The sub-camera 13 is a camera for photographing wafers that pose a problem when being photographed by the main camera 12, and is arranged based on the position of a specific wafer Ws that cannot be photographed clearly due to the presence of the protrusions 59. be done. The operator arranges the sub-camera 13 at a position where the specific wafer Ws and the wafers W adjacent to the specific wafer Ws before and after the specific wafer Ws can be photographed. If there are a plurality of wafers W obstructed by the protrusions 59, a corresponding number of sub-cameras 13 are installed.

The position and angle of the sub camera 13 can be changed. As a result, even if the wafer W is accommodated in the container 50 having the protrusions 59 at different positions and the wafer W interferes with the protrusions 59 in the photographed image, the position and angle of the sub-camera 13 can be changed. can respond. That is, the specific wafer Ws photographed by the sub-camera 13 can be changed as required.
A correlation table of the positions and angles of the container 50 and the sub-camera 13 may be displayed inside the inspection apparatus 1 in order to facilitate the determination of the position of the sub-camera 13 . This correlation table may be displayed on a display unit, which will be described later. Also, a positioning device may be provided so that the position and angle of the sub-camera 13 can be easily changed.

Next, an inspection method using the inspection apparatus of this embodiment will be described.
As shown in FIG. 7, the inspection method of this embodiment is a method for inspecting the position of the wafer W in the container 50, and includes a container discrimination step S81, a first imaging step S82, and a second imaging step S83. , an analysis step S84, a display step S85, a determination step S86, and a confirmation step S87.

The container discriminating step S81 is a step of discriminating the type of the container 50 based on ON/OFF of the contact sensor. In the container determination step S81, the analysis processing unit 18 acquires the ON/OFF state of the contact sensor, and based on this information, determines whether the container 50 is the first container 50A or the second container 50B.
In the present embodiment, the contact sensor is used to identify the container 50, but an image captured by a camera may be added to the identification material, or the type of the container 50 may be determined based only on the image captured by the camera. good too.

The first photographing step S82 is a step of photographing the entire plurality of wafers W housed in the container 50 through the container 50 from a direction parallel to the main surfaces of the wafers W. As shown in FIG.
In the first photographing step S82, the device control unit 16 controls the container transfer device 3 so that the container 50 moves to the first photographing position P1, and the main camera 12 so that the whole of the plurality of wafers W is photographed. and infrared illumination 14 .

The second photographing step S83 is a step of photographing a specific wafer Ws through the container 50 from a direction inclined with respect to the direction parallel to the main surface of the wafer W.
In the second photographing step S83, the device control unit 16 controls the container transfer device 3 so that the container 50 moves to the second photographing position P2, and the sub-camera 13 so that the specific wafer Ws is photographed. to control.
If the container 50 is determined to be the first container 50A in the container determination step S81, the sub-camera 13 can omit the photographing because the container has no protrusion.

In the analysis step S84, the analysis processing unit 18 counts the number of wafers W based on the images captured by the cameras 12 and 13, and inspects the positional deviation of the wafers W. FIG.
When the container is the second container 50B, the image captured by the main camera 12 is as shown in FIG. 8, and the image captured by the sub-camera 13 is as shown in FIG. As shown in FIGS. 8 and 9, in the images captured by the cameras 12 and 13, the periphery of the wafer W is displayed in a straight line suitable for image processing.

As shown in FIG. 8, some wafers W (specific wafers Ws) become unclear due to the projections 59, so the analysis processing unit 18 detects wafers W other than the specific wafers Ws from the image of the main camera 12. are counted, and the presence or absence of misalignment of wafers W other than the specific wafer Ws is inspected.
In the image shown in FIG. 8, the counted wafers W are numbered. Also, based on the image, it is determined that the wafer W numbered 9 is misaligned.

Next, the analysis processing unit 18 counts the number of specific wafers Ws based on the image captured by the sub-camera 13 and confirms the positional deviation of the specific wafers Ws.
In the image shown in FIG. 9, a specific wafer Ws is counted, and it is determined that there is no displacement from the relationship with the wafers W before and after the specific wafer Ws.

In the display step S<b>85 , the controller 5 displays the counted number of wafers W and the presence or absence of positional displacement of the wafers W on the output unit 19 . In the examples shown in FIGS. 8 and 9, the output unit 19 displays the number of wafers W and, if misalignment occurs, that fact.
In the determination step S86, the operator determines whether or not the wafer W is misaligned based on the displayed information. If there is no problem with the wafer W, the inspection ends.
If the wafer W is misaligned, the operator opens the container 50 and checks the surface condition of the wafer W to see if the wafer W is scratched or the like in a checking step S87. At this time, if there is no damage or the like, the wafer W is put back into the container 50 after correcting the positional deviation, and the wafer W in the container 50 is inspected again. After the inspection, if there is no problem such as misalignment, the inspection ends.

Next, a silicon wafer manufacturing method including the inspection method of this embodiment will be described.
The silicon wafer manufacturing method is a method of manufacturing silicon wafers using the Czochralski method, inspecting the positions of a plurality of wafers W in the container 50 by the inspection method described above, and then shipping the wafers.

As shown in FIG. 10, the method for manufacturing a silicon wafer includes a pulling step S1, a block processing step S2, a slicing step S3, a polishing step S4, a cleaning step S5, a wafer final inspection step S6, and a container storage step. It has a process S7, an in-container wafer inspection process S8, a packaging process S9, and a packing/shipping process S10.

The pulling step S1 is a step of pulling a silicon single crystal from a silicon melt using the Czochralski method. Thereby, a cylindrical single crystal ingot is obtained.
The block processing step S2 is a step of processing the single crystal ingot into blocks. In the block processing step S2, the outer periphery of the single crystal ingot is ground, and after notching according to the crystal orientation, the single crystal ingot is cut into a plurality of blocks by, for example, a band saw.

In the slicing step S3, the block is sliced into a plurality of silicon wafers having a thickness of about 1 mm, for example, by an inner peripheral blade cutting machine or a wire saw.
In the polishing step S4, rough polishing (lapping) is performed with, for example, an alumina abrasive material so that both surfaces of the wafer are parallel, and etching or the like is performed as necessary, and then the unevenness of the wafer surface is eliminated to achieve a high degree of flatness. In order to achieve a mirror finish, polishing is performed using, for example, a colloidal silica liquid.
In the cleaning step S5, each silicon wafer is cleaned with, for example, an alkaline solution.

The wafer final inspection step S6 is a step of inspecting surface particles, flaws, etc. existing on the silicon wafer using a wafer surface inspection apparatus or the like.
The container storing step S7 is a step of selecting the wafers determined to be non-defective in the wafer final inspection step S6 and storing the wafers in a container. Wafers may be loaded automatically by the apparatus or may be loaded manually. At this time, a label containing lot information and the like for wafer identification is attached to the container. Finally, the container 50 is closed by the lid 53 in the container housing step S7.

Next, as the in-container wafer inspection step S8, the above-described method for inspecting the position of the wafer W in the container 50 is performed. The in-container wafer inspection step S8 is performed after the container storage step S7. Since the in-container wafer inspection step S8 is performed without opening the lid 53, the cleanliness of the inside of the container 50 can be maintained.
The packaging step S9 is a step of packaging the shipping container. In the packaging step S9, the container 50 is preferably double-packaged, for example, with a transparent plastic film and an aluminum-containing opaque film.
The packing/shipping step S10 is a step of storing the wrapped container in a packing material such as cardboard and shipping it.

According to the above-described embodiment, there is a projection 59 (unevenness) on a part of the container 50, and even if the projection 59 prevents some of the plurality of wafers W from being photographed by the main camera 12, the main camera 12 cannot photograph a specific part of the wafer W. By photographing the wafers Ws with the sub-camera 13, it is possible to count the number of wafers W and to detect the displacement of the wafers W.

In addition, the main camera 12 is an infrared camera, and the provision of the infrared illumination 14 for irradiating infrared rays toward the main camera 12 allows the container 50 to be made of a translucent material. Also, the inspection accuracy of the obtained image can be improved.
That is, by using an infrared camera having a wavelength that passes through the container 50 as the main camera, the wafers W can be inspected even if the container 50 is not formed so that the wafers W can be visually recognized. .

In the above description, two types of containers 50A and 50B are used as the container 50, but the container 50 is not limited to this, and may correspond to more types of containers.
Also, for example, the inspection accuracy may be improved by adding a camera that takes pictures from below.

DESCRIPTION OF SYMBOLS 1... Inspection apparatus, 2... Case, 3... Container conveying apparatus, 4... Photographing apparatus, 5... Control apparatus, 7... Frame, 8... Cover, 9... Opening, 10... Belt conveyor, 11... Shutter, 12... Main camera 13 Sub camera 14 Infrared illumination 16 Apparatus control unit 17 Analysis unit 18 Analysis processing unit 19 Output unit 50 Container 50A First container 50B Second Container No. 2 51 Container body 53 Lid 54 Upper surface 54B Upper surface 55 Side surface 57 Alignment slot 58 Wafer holder 59 Protrusion P0 Placement position P1... First imaging position, P2... Second imaging position, W... Wafer, Ws... Wafer.

Claims (14)

A method for inspecting a plurality of wafers stored in a container made of a transparent or semi-transparent material, arranged parallel to each other and at regular intervals so that their central axes are aligned,
The container is a first container having a flat first top surface or a second container having a second top surface having a step,
The inspection method is
a container discrimination step of discriminating the type of container to be inspected;
a first photographing step of photographing the entirety of the plurality of wafers through the container from a direction parallel to the principal surfaces of the wafers above the container ;
a second photographing step of photographing the wafer through the container from a direction inclined with respect to the direction parallel to the main surface of the wafer on the upper side of the container ;
an inspection step of inspecting the positions of the plurality of wafers in the container using the images captured in the first imaging step and the second imaging step ;
The inspection method , wherein the first imaging step, the second imaging step, or the inspection step is performed in a state according to the determination result in the container determination step. The container is the first container, or a plurality of types of the second container having a second upper surface portion formed with steps at different positions,
In the second imaging step, when the container to be inspected is any one of the plurality of types of second containers, the imaging position and angle of the wafer are changed according to the type of the second container. 2. The inspection method according to claim 1, wherein the photographing is performed by In the inspecting step, the number of the plurality of wafers is counted using the images captured in the first imaging step and the second imaging step, and misalignment of the plurality of wafers is inspected. The inspection method according to claim 1 or 2 . When the container to be inspected is the first container, in the inspection step, only the image captured in the first imaging step is used to determine the inside of the first container without performing the second imaging step. inspecting the positions of the plurality of wafers;
When the container to be inspected is the second container, in the inspection step, the plurality of wafers in the second container are inspected using the images captured in the first imaging step and the second imaging step. 3. The inspection method according to claim 1, wherein a position is inspected. In the inspection process,
when the container to be inspected is the first container, counting the number of the plurality of wafers using only the image captured in the first imaging step, and inspecting the positional deviation of the plurality of wafers;
When the container to be inspected is the second container, the number of the plurality of wafers is counted using the images captured in the first imaging step and the second imaging step, and the positions of the plurality of wafers are counted. 5. The inspection method according to claim 4, wherein deviation is inspected. 6. The method according to any one of claims 1 to 5, wherein, in the first photographing step, photographing is performed using an infrared camera, and infrared rays are irradiated through the container from the opposite side of the infrared camera toward the infrared camera. The inspection method according to any one of the items . A method for manufacturing silicon wafers, comprising inspecting the plurality of wafers in the container using the inspection method according to any one of claims 1 to 6 . An inspection apparatus for a plurality of wafers stored in a container made of a transparent or semi-transparent material, arranged parallel to each other and at equal intervals so that their central axes are aligned,
The container is a first container having a flat first top surface or a second container having a second top surface having a step,
The inspection device is
a contact sensor for determining the type of container to be inspected;
a main camera that captures the entirety of the plurality of wafers through the container from a direction parallel to the principal surfaces of the wafers above the container ;
a sub-camera for photographing the wafer through the container from a direction inclined with respect to the direction parallel to the main surface of the wafer on the upper side of the container ;
an analysis device that inspects the positions of the plurality of wafers in the container using images captured by the main camera and the sub-camera;
An inspection device, comprising: a processing unit that performs processing related to the main camera, the sub-camera, or the inspection device in a state according to a determination result of the contact sensor. The container is the first container, or a plurality of types of the second container having a second upper surface portion formed with steps at different positions,
When the container to be inspected is any one of the plurality of types of second containers, the processing unit controls the imaging position and angle of the wafer by the sub camera according to the type of the second container. 9. The inspection apparatus according to claim 8, further comprising a positioning device for changing the . The analysis device counts the number of the plurality of wafers using the images captured by the main camera and the sub-camera, and has a function of inspecting positional deviation of the plurality of wafers. The inspection device according to claim 8 or 9 . The processing unit is composed of a device control unit that controls the main camera and the sub camera, and the analysis device,
When the container to be inspected is the first container, after the device control unit controls only the main camera to image the wafer, the analysis device detects only the image captured by the main camera. inspecting the positions of the plurality of wafers in the first container using
When the container to be inspected is the second container, after the device control unit controls the main camera and the sub camera to image the wafer, the analysis device controls the main camera and the sub camera. 10. The inspection apparatus according to claim 8, wherein an image captured by a camera is used to inspect the positions of the plurality of wafers in the second container. The analysis device is
when the container to be inspected is the first container, counting the number of the plurality of wafers using only the image captured by the main camera, and inspecting positional deviation of the plurality of wafers;
When the container to be inspected is the second container, the number of the plurality of wafers is counted using the images captured by the main camera and the sub camera, and positional deviation of the plurality of wafers is inspected. 12. The inspection apparatus according to claim 11, characterized in that: the container accommodates the plurality of wafers so that their central axes are horizontal;
13. The inspection apparatus according to any one of claims 8 to 12, wherein the sub-camera is arranged such that its optical axis is inclined by 40° to 80° with respect to the main surfaces of the plurality of wafers. The main camera is an infrared camera,
14. The inspection device according to any one of claims 8 to 13, wherein the inspection device has an infrared illuminator that irradiates infrared rays toward the main camera from the opposite side of the main camera through the container. inspection equipment.

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