A silicon wafer position detection device

Abstract

The application provides a silicon wafer position detection device, wherein the device comprises a base, a vertical support, a moving piece arranged on the vertical support, a placing table, a motor, a signal transmitter, a signal receiver and a controller, one end of the vertical support is fixedly connected with the base, the other end of the vertical support is fixedly provided with the signal transmitter and the signal receiver respectively, the signal transmitter and the signal receiver are arranged in alignment, a movable space is formed between the signal transmitter and the signal receiver, the placing table is used for supporting a silicon wafer box, a plurality of silicon wafers are placed in the silicon wafer box, the placing table is connected with the moving piece, the moving piece is driven to move under the rotation of the motor to control the placing table to move in the vertical direction, so that the plurality of silicon wafers in the silicon wafer box pass through the movable space in turn, and the controller determines the placing condition of the plurality of silicon wafers in the silicon wafer box according to the corresponding detection time of the signal receiver. The effect of accurately detecting the placing condition of the silicon wafers in the silicon wafer box is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a wafer position detection device. BACKGROUND

[0002] In the process of manufacturing semiconductor integrated circuits, a photolithography device is the most important device, which exposes a circuit diagram on a silicon wafer with a photosensitive coating, and then performs processes such as deposition, etching, and doping to finally form an integrated circuit. Before the wafer is transported to the photolithography device for exposure, the wafer is stored in a wafer box, and therefore, the storage state of the wafer in the wafer box, including whether the wafer is included, stacked, or inserted obliquely, is detected to provide a prerequisite for the subsequent process.

[0003] At present, the existing technical solutions are all methods of installing a reflective laser sensor on the side of the wafer box to detect the time of wafer side shielding. The specific operation is as follows: start the wafer box lifting, the laser irradiation continues to irradiate, the laser is shielded by the wafer side, and is reflected back to the sensor, and the sensor state can be changed from low level to high level, and finally the state of the wafer is calculated by detecting the fixed wafer slot position level state and time.

[0004] However, the performance of laser reflection is greatly affected by the state of the wafer side surface, and when the wafer side surface smoothness and shape deviation are large, the laser reflection intensity is greatly deviated, which greatly affects the sensor detection accuracy, and thus the wafer state inspection is not accurate. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a wafer position detection device, which can control the movement of the placement table, so that the wafers in the wafer box pass through the movable space between the signal transmitter and the signal receiver, and determine the placement of the wafers in the wafer box according to the detection time of the signal receiver received by the controller. The problem that the performance of laser reflection is greatly affected by the state of the wafer side surface, and when the wafer side surface smoothness and shape deviation are large, the laser reflection intensity is greatly deviated, which greatly affects the sensor detection accuracy, and thus the wafer state inspection is not accurate, is solved, and the wafer placement in the wafer box is accurately detected.

[0006] The embodiment of the present application provides a silicon wafer position detection device, the device comprises a base, a vertical support, a moving part arranged on the vertical support, a placing table, a motor, a signal transmitter, a signal receiver and a controller, one end of the vertical support is fixedly connected with the base, the other end of the vertical support is fixedly provided with the signal transmitter and the signal receiver respectively, the signal transmitter and the signal receiver are arranged in alignment, and a movable space is formed between the signal transmitter and the signal receiver, the placing table is used for supporting a silicon wafer box, a plurality of silicon wafers are placed in the silicon wafer box, the placing table is connected with the moving part, the moving part is driven to move under the rotation of the motor, the placing table is controlled to move in the vertical direction, so that the plurality of silicon wafers in the silicon wafer box pass through the movable space in turn, and the controller determines the placing condition of the plurality of silicon wafers in the silicon wafer box according to the detection time corresponding to the signal receiver.

[0007] Optionally, the silicon wafer box comprises an upper panel, a lower panel, a first side panel and a second side panel, a first side edge of the first side panel is fixedly connected with a first side edge of the upper panel, a second side edge of the first side panel is fixedly connected with a first side edge of the lower panel, a first side edge of the second side panel is fixedly connected with a second side edge of the upper panel, and a second side edge of the second side panel is fixedly connected with a second side edge of the lower panel, wherein the first side edge of the first side panel and the second side edge of the first side panel are two opposite side edges, the first side edge of the second side panel and the second side edge of the second side panel are two opposite side edges, the first side edge of the upper panel and the second side edge of the upper panel are two opposite side edges, and the first side edge of the lower panel and the second side edge of the lower panel are two opposite side edges, silicon wafer placing grooves are arranged at a plurality of preset positions of the first side panel, and silicon wafer placing grooves are arranged at positions where the second side panel is aligned with the plurality of preset positions of the first side panel, and the plurality of silicon wafers are respectively placed in a plurality of slots formed between the plurality of placing grooves of the first side panel and the plurality of placing grooves of the second side panel.

[0008] Optionally, the interval between the plurality of preset positions of the first side panel is a standard interval value, and the interval between the plurality of preset positions of the second side panel is the standard interval value.

[0009] Optionally, the controller is connected with the motor, and the controller controls the motor to rotate to drive the moving part to control the placing table to move in the vertical direction in the following manner: the motor is controlled to rotate to drive the placing table to move to a first height; the motor is controlled to rotate at a predetermined rotation speed and in a predetermined rotation direction to drive the moving part to control the placing table to move in the vertical direction at a predetermined speed; it is judged whether the placing table moves to a second height; and if the placing table moves to the second height, the motor is controlled to stop rotating.

[0010] Optionally, the detection time comprises a plurality of valid signal detection time periods and a plurality of invalid signal detection time periods, wherein the valid signal detection time period is used to indicate that a wafer passes through the movable space during the time period, and the invalid signal detection time period is used to indicate that no wafer passes through the movable space during the time period.

[0011] Optionally, the controller determines the placement of each wafer in the wafer box according to the detection time corresponding to the signal receiver by: determining whether each wafer detection time period comprises a valid signal detection time period; and for each wafer detection time period, if the wafer detection time period does not comprise a valid signal detection time period, determining the position of the wafer slot corresponding to the wafer detection time period according to the wafer detection time period, and determining that the wafer slot at the position is an empty slot.

[0012] Optionally, the controller further performs the following steps: for each wafer detection time period, if the wafer detection time period comprises a valid signal detection time period, calculating the time length of the valid signal detection time period, and determining whether the time length of the valid signal detection time period exceeds a reference time length; and for each wafer detection time period, if the time length of the valid signal detection time period exceeds the reference time length, determining the position of the wafer slot corresponding to the wafer detection time period, and determining that the wafer in the wafer slot at the position is placed in a stacking manner.

[0013] Optionally, the controller further performs the following steps: for each wafer detection time period, if the time length of the valid signal detection time period does not exceed the reference time length, determining whether the valid signal detection time period is contained in a reference time period within the wafer detection time period; if the valid signal detection time period is contained in the reference time period within the wafer detection time period, determining the position of the wafer slot corresponding to the wafer detection time period, and determining that the wafer in the wafer slot at the position is normally placed; and if the valid signal detection time period is not contained in the reference time period within the wafer detection time period, determining the position of the wafer slot corresponding to the wafer detection time period, and determining that the wafer in the wafer slot at the position is placed in a wrong slot.

[0014] Optionally, the controller determines each wafer detection time period by: determining the movement speed of the placement table according to the predetermined rotation speed of the motor; determining the time length of the wafer detection time period according to the movement speed of the placement table and the standard interval value; and determining each wafer detection time period according to the position of each slot, the time length of the wafer detection time period, the first height, and the second height.

[0015] Optionally, the controller further performs the following steps: judging whether the silicon wafer in each silicon wafer slot position in the silicon wafer box is normally placed; if the silicon wafer in each silicon wafer slot position in the silicon wafer box is not normally placed, determining the silicon wafer box as an abnormal silicon wafer box.

[0016] The silicon wafer position detection device provided by the embodiment of the present application can control the movement of the placement table, so that the silicon wafers in the silicon wafer box pass through the movable space between the signal transmitter and the signal receiver, and the placement of the silicon wafers in the silicon wafer box is determined according to the detection time of the signal receiver received by the controller. The problem that the performance of laser reflection is greatly affected by the state of the side surface of the wafer in the prior art is solved. When the wafer side surface smoothness and shape deviation are large, the laser reflection intensity is also large, which greatly affects the detection accuracy of the sensor, and thus the wafer state check is not accurate. The silicon wafer position detection device provided by the embodiment of the present application can accurately detect the placement of the silicon wafers in the silicon wafer box.

[0017] In order to make the above objectives, characteristics and advantages of the present application more apparent, the following will describe a preferred embodiment in detail, and the accompanying drawings will be described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0019] Figure 1 A schematic diagram of a silicon wafer detection device provided by the embodiment of the present application;

[0020] Figure 2 A schematic diagram of a silicon wafer box provided by the embodiment of the present application;

[0021] Figure 3 A flowchart of the controller controlling the motor provided by the embodiment of the present application;

[0022] Figure 4 A flowchart of the controller determining the placement of each silicon wafer in the silicon wafer box provided by the embodiment of the present application;

[0023] Figure 5 A silicon wafer position schematic diagram in the silicon wafer box provided by the embodiment of the present application. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0025] First, the applicable scenarios for this application will be introduced. This application can be applied to the field of semiconductor manufacturing technology.

[0026] Research has shown that photolithography equipment is the most crucial piece of equipment in the semiconductor integrated circuit manufacturing process. It exposes the circuit pattern onto a silicon wafer coated with a photosensitive layer, followed by deposition, etching, doping, and other processes to ultimately form the integrated circuit. Before being transported to the photolithography equipment for exposure, the silicon wafers are stored in wafer cassettes. Therefore, monitoring the storage status of the wafers in the cassettes, including their presence, stacking, and angled insertion, provides a prerequisite for subsequent processes.

[0027] Currently, existing technical solutions all involve installing a reflective laser sensor on the side of the wafer cassette to detect the duration of side occlusion on the wafer. The specific operation is as follows: the wafer cassette is raised and lowered, and the laser continuously illuminates the wafer. When the laser is blocked by the side of the wafer, it is reflected back to the sensor, causing the sensor's state to change from low to high. Finally, the state of the silicon wafer is calculated by detecting the voltage level at a fixed wafer slot position and the duration of the illumination.

[0028] However, the performance of laser reflection is greatly affected by the surface condition of the wafer side. When the surface finish and shape of the wafer side deviate significantly, the laser reflection intensity deviates accordingly, which greatly affects the detection accuracy of the sensor and thus makes the inspection of the silicon wafer condition inaccurate.

[0029] Based on this, embodiments of this application provide a silicon wafer position detection device.

[0030] Please see Figure 1 , Figure 1 This is a schematic diagram of a silicon wafer inspection device provided in an embodiment of this application. Figure 1As shown in the figure, the silicon wafer inspection device provided in this application embodiment includes: a base 101, a vertical support 102, a movable part 103 disposed on the vertical support, a placement platform 104, a motor 105, a signal transmitter 106, a signal receiver 107, a controller (not shown in the figure), and a silicon wafer box 108.

[0031] Specifically, one end of the vertical bracket 102 is fixedly connected to the base 101, and the other end of the vertical bracket 102 is fixed with a signal transmitter 106 and a signal receiver 107 respectively.

[0032] The signal transmitter 106 and the signal receiver 107 are aligned and a movable space is formed between them.

[0033] It should be noted that the signal transmitter 106 and the signal receiver 107 are respectively connected to the controller. In order to adapt to the deformation of the silicon wafer within a certain range, the signal transmission and signal reception angles of the signal transmitter 106 and the signal receiver 107 can be finely adjusted according to the control of the controller so that the signal transmitter 106 and the signal receiver 107 can accurately detect the position of the silicon wafer.

[0034] Please see Figure 1 The placement platform 104 is used to hold the silicon wafer box 108, which contains multiple silicon wafers (not shown in the figure).

[0035] The placement stage 104 is connected to the moving part 103. The moving part 103 is moved by the rotation of the motor 105 to control the movement of the placement stage 104 in the vertical direction, so that multiple silicon wafers (not shown in the figure) in the silicon wafer box 108 pass through the movable space in sequence. The controller (not shown in the figure) determines the placement of the multiple silicon wafers in the silicon wafer box according to the detection time corresponding to the signal receiver.

[0036] Please see Figure 2 , Figure 2 This is a schematic diagram of a silicon wafer cassette provided in an embodiment of this application. Figure 2 As shown in the figure, the silicon wafer cassette provided in this application embodiment includes: an upper panel 202, a lower panel 201, a first side panel 203, a second side panel 204, a handle 206, and a silicon wafer 205, wherein a plurality of silicon wafer placement slots 207 are formed on the first side panel 203 and the second side panel 204.

[0037] The first side of the first side panel 203 is fixedly connected to the first side of the upper panel 202, the second side of the first side panel 203 is fixedly connected to the first side of the lower panel 201, the first side of the second side panel 204 is fixedly connected to the second side of the upper panel 202, and the second side of the second side panel 204 is fixedly connected to the second side of the lower panel 201.

[0038] Among them, the first side edge and the second side edge of the first side panel 203 are two opposite sides, the first side edge and the second side edge of the second side panel 204 are two opposite sides, the first side edge and the second side edge of the upper panel 202 are two opposite sides, and the first side edge and the second side edge of the lower panel 201 are two opposite sides.

[0039] like Figure 2 As shown, silicon wafer placement slots are provided at multiple preset positions on the first side panel 203, and silicon wafer placement slots 207 are provided at positions on the second side panel 204 that are aligned with multiple preset positions on the first side panel 203. Multiple silicon wafers 205 are respectively placed in multiple slots formed between the multiple placement slots of the first side panel 203 and the multiple placement slots 207 of the second side panel 204.

[0040] The spacing between multiple preset positions of the first side panel 203 is a standard spacing value, and the spacing between multiple preset positions of the second side panel 204 is a standard spacing value.

[0041] In this way, when the silicon wafer is moved in the wafer cassette, the wafer is placed in the slot of the wafer cassette. Before the wafer is transported to the photolithography equipment for exposure, the storage status of the wafer in the wafer cassette can be determined by detecting the position of each wafer in the wafer cassette.

[0042] The controller is connected to the motor so that the motor's movement can be controlled by the controller.

[0043] Specifically, when determining the storage status of silicon wafers in the wafer cassette, it is necessary to control the placement stage to move at a preset speed and direction to ensure the accuracy of silicon wafer position detection.

[0044] For example, please refer to Figure 3 , Figure 3 This is a flowchart illustrating the controller controlling the motor provided in an embodiment of this application. Figure 3 The flowchart shown in the embodiment of this application illustrates the controller controlling the motor, including:

[0045] S301. Control the motor to rotate so that the placement platform moves to the first height.

[0046] In this step, the placement platform can be moved to the first height by controlling the motor to run at a predetermined speed for a predetermined time, or by using a limit switch for detection.

[0047] S302. Control the motor to rotate at a predetermined speed and in a predetermined direction, driving the moving part to control the placement platform to move vertically at a predetermined speed.

[0048] For example, the predetermined rotation speed can be 150 revolutions per minute, and the predetermined rotation direction can be forward rotation, so as to drive the moving part to control the placement table to move vertically from top to bottom at a speed of five millimeters per second.

[0049] S303. Determine whether the placement platform has moved to the second height.

[0050] In this step, it can be determined whether the placement platform has moved to the second height based on the motor's rotation time, the limit switch set at the second height, or other methods.

[0051] S304. If the placement platform moves to the second height, the motor is controlled to stop rotating.

[0052] In this way, the controller can control the motor to rotate and drive the moving parts to move at a predetermined speed along a predetermined vertical direction.

[0053] During the process of the controller controlling the motor to rotate and drive the moving parts to control the vertical movement of the placement platform, the signal transmitter continuously transmits signals and the signal receiver continuously receives signals. The controller determines the placement of each silicon wafer in the silicon wafer box based on the detection time corresponding to the signal receiver.

[0054] For details, please refer to Figure 4 , Figure 4 This is a flowchart illustrating how the controller provided in this embodiment determines the placement of each silicon wafer within the wafer cassette. Figure 4 As shown in the flowchart, the controller provided in this application embodiment determines the placement of each silicon wafer within the wafer cassette, including:

[0055] S401. Determine whether the detection time period for each silicon wafer includes a valid signal detection time period.

[0056] It should be noted that the detection time includes multiple valid signal detection time periods and multiple invalid signal detection time periods. The valid signal detection time periods are used to indicate that a silicon wafer passes through the movable space during the time period, and the invalid signal detection time periods are used to indicate that no silicon wafer passes through the movable space during the time period.

[0057] The silicon wafer inspection time period is determined based on the moving speed of the placement stage and the distance between the preset positions of each slot.

[0058] For example, please refer to Figure 5 , Figure 5This is a schematic diagram showing the position of the silicon wafers within a wafer cassette provided in an embodiment of this application. Figure 5 As shown in the figure, the silicon wafer positions in the silicon wafer cassette provided in this application embodiment include: silicon wafer 501, silicon wafer 502, silicon wafer 503, silicon wafer 504, silicon wafer 505, position A, position B, position C, position D, position E, and position F.

[0059] Here, each silicon wafer is placed in a slot in the wafer cassette, and the distance between each adjacent silicon wafer is the distance between the preset positions of each adjacent silicon wafer placement slot.

[0060] It should be noted that when the placement stage moves to the first height, position A inside the silicon wafer box is between the signal transmitter and the signal receiver. The distance between position A and position B is the spacing value between multiple preset positions, which is the standard spacing value; the distance between position B and position C is the standard spacing value; the distance between position C and position D is the standard spacing value; the distance between position D and position E is the standard spacing value; and the distance between position E and position F is the standard spacing value.

[0061] Thus, when the controller controls the placement platform to move from the first height to the second height at a preset speed, the detection time period for silicon wafer 501 is the time period during which the placement platform moves at the preset speed to the standard spacing value. For example, if the time to move at the preset speed to the standard spacing value is 1 second, the silicon wafer detection time period for silicon wafer 501 is 0-1 seconds, the silicon wafer detection time period for silicon wafer 502 is 1-2 seconds, the silicon wafer detection time period for silicon wafer 503 is 2-3 seconds, the silicon wafer detection time period for silicon wafer 504 is 3-4 seconds, and the silicon wafer detection time period for silicon wafer 505 is 4-5 seconds.

[0062] For each silicon wafer detection time period, if the silicon wafer detection time period does not include the effective signal detection time period, then according to the silicon wafer detection time period, step S402 is executed to determine the position of the silicon wafer slot corresponding to the silicon wafer detection time period, and the silicon wafer slot at that position is determined to be an empty slot.

[0063] For each silicon wafer detection time period, if the silicon wafer detection time period includes an effective signal detection time period, then step S403 is executed: calculate the length of the effective signal detection time period, and determine whether the length of the effective signal detection time period exceeds the reference time length.

[0064] For each silicon wafer detection time period, if the length of the effective signal detection time period exceeds the reference time length, then step S404 is executed to determine the position of the silicon wafer slot corresponding to the silicon wafer detection time period, and to determine that the silicon wafers in the silicon wafer slot at that position are stacked.

[0065] For each silicon wafer detection time period, if the length of the effective signal detection time period does not exceed the reference time length, then step S405 is executed to determine whether the effective signal detection time period is included in the reference time period within the silicon wafer detection time period.

[0066] If the effective signal detection time period is included in the reference time period within the silicon wafer detection time period, then step S407 is executed to determine the position of the silicon wafer slot corresponding to the silicon wafer detection time period, and to determine that the silicon wafer in the silicon wafer slot at that position is normally placed.

[0067] If the effective signal detection time period is not included in the reference time period within the silicon wafer detection time period, then step S406 is executed to determine the position of the silicon wafer slot corresponding to the silicon wafer detection time period, and to determine that the silicon wafer in the silicon wafer slot at that position is misplaced.

[0068] A silicon wafer position detection device can control the movement of a placement stage to allow silicon wafers within a wafer cassette to pass through a movable space between a signal transmitter and a signal receiver. Based on the detection time of the signal receiver received by the controller, the device determines the placement of multiple silicon wafers within the wafer cassette. This solves the problem in existing technologies where laser reflection performance is significantly affected by the surface condition of the wafer side. When there are large deviations in the smoothness and shape of the wafer side, the laser reflection intensity also deviates significantly, resulting in a substantial impact on sensor detection accuracy and inaccurate wafer condition checks. The device achieves accurate detection of the placement of silicon wafers within the wafer cassette.

[0069] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described actions. Figure 3 as well as Figure 4 The control steps executed by the controller in the method embodiment shown are specifically implemented in the method embodiment and will not be repeated here.

[0070] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0071] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0072] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0073] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0074] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0075] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A silicon wafer position detection device, characterized in that, The device includes a base, a vertical support, a movable component mounted on the vertical support, a placement platform, a motor, a signal transmitter, a signal receiver, and a controller. One end of the vertical support is fixedly connected to the base, and a signal transmitter and a signal receiver are respectively fixed to the other end of the vertical support. The signal transmitter and the signal receiver are aligned and a movable space is formed between them. The placement platform is used to hold a silicon wafer box containing multiple silicon wafers. The placement platform is connected to the moving component. The moving component is driven by the rotation of the motor to control the vertical movement of the placement platform, so that the multiple silicon wafers in the silicon wafer box pass through the movable space in sequence. The controller determines the placement of the plurality of silicon wafers within the silicon wafer cassette based on the detection time corresponding to the signal receiver. The silicon wafer cassette includes a top panel, a bottom panel, a first side panel, and a second side panel. A first side edge of the first side panel is fixedly connected to a first side edge of the top panel, and a second side edge of the first side panel is fixedly connected to a first side edge of the bottom panel. The first side edge of the second side panel is fixedly connected to a second side edge of the top panel, and a second side edge of the second side panel is fixedly connected to a second side edge of the bottom panel. Specifically, the first side edge and the second side edge of the first side panel are opposite sides; the first side edge and the second side edge of the second side panel are opposite sides; the first side edge and the second side edge of the top panel are opposite sides; and the first side edge and the second side edge of the bottom panel are opposite sides. A silicon wafer placement slot is provided at multiple preset positions on the first side panel, and a silicon wafer placement slot is provided at a position on the second side panel that is aligned with multiple preset positions on the first side panel. Multiple silicon wafers are respectively placed in multiple slots formed between the multiple placement slots on the first side panel and the multiple placement slots on the second side panel. The spacing between multiple preset positions on the first side panel is a standard spacing value, and the spacing between multiple preset positions on the second side panel is a standard spacing value.

2. The apparatus according to claim 1, characterized in that, The controller is connected to the motor. The controller controls the vertical movement of the placement platform by controlling the rotation of the motor to drive the moving parts: Control the motor to rotate so that the placement platform moves to a first height; The control motor rotates at a predetermined speed and in a predetermined direction, driving the moving parts to control the placement platform to move vertically at a predetermined speed; Determine whether the placement platform has moved to the second height; If the placement platform moves to the second height, the control motor stops rotating.

3. The apparatus according to claim 1, characterized in that, The detection time includes multiple valid signal detection time periods and multiple invalid signal detection time periods. The valid signal detection time period is used to indicate that a silicon wafer passes through the movable space during that time period, while the invalid signal detection time period is used to indicate that no silicon wafer passes through the movable space during that time period.

4. The apparatus according to claim 3, characterized in that, The controller determines the placement of each silicon wafer within the wafer cassette based on the detection time corresponding to the signal receiver in the following manner: Determine whether each silicon wafer detection time period includes a valid signal detection time period; For each silicon wafer detection time period, if the detection time period does not include the effective signal detection time period, then the position of the silicon wafer slot corresponding to the detection time period is determined based on the detection time period, and the silicon wafer slot at that position is determined to be an empty slot.

5. The apparatus according to claim 4, characterized in that, The controller also performs the following steps: For each silicon wafer detection time period, if the silicon wafer detection time period includes an effective signal detection time period, then the length of the effective signal detection time period is calculated, and it is determined whether the length of the effective signal detection time period exceeds the reference time length. For each silicon wafer detection time period, if the length of the effective signal detection time period exceeds the reference time length, the position of the silicon wafer slot corresponding to that silicon wafer detection time period is determined, and the silicon wafers in the silicon wafer slot at that position are determined to be stacked.

6. The apparatus according to claim 5, characterized in that, The controller also performs the following steps: For each silicon wafer detection time period, if the length of the effective signal detection time period does not exceed the reference time length, then it is determined whether the effective signal detection time period is included in the reference time period within the silicon wafer detection time period. If the effective signal detection time period is included in the reference time period within the silicon wafer detection time period, then the position of the silicon wafer slot corresponding to the silicon wafer detection time period is determined, and the silicon wafer in the silicon wafer slot at that position is determined to be normally placed. If the effective signal detection time period is not included in the reference time period within the silicon wafer detection time period, then the position of the silicon wafer slot corresponding to the silicon wafer detection time period is determined, and the silicon wafer in the silicon wafer slot at that position is determined to be misplaced.

7. The apparatus according to claim 1 or 5, characterized in that, The controller determines the detection time period for each silicon wafer through the following steps: The moving speed of the placement platform is determined based on the predetermined rotation speed of the motor; The time length of the silicon wafer inspection period is determined based on the moving speed of the placement stage and the standard spacing value. The detection time period for each silicon wafer is determined based on the location of each slot, the length of the silicon wafer detection time period, the first height, and the second height.

8. The apparatus according to claim 6, characterized in that, The controller also performs the following steps: Determine whether the silicon wafers in each silicon wafer slot within the silicon wafer cassette are properly positioned. If the silicon wafers in each silicon wafer slot within the silicon wafer box are not all properly placed, then the silicon wafer box is identified as an abnormally placed silicon wafer box.

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