Load port

Abstract

According to the present invention, the amount of deflection of a substrate in a container is calculated without rotating the container.　A load port 4 comprises: a support frame 43; a placement unit 44 on which a FOUP 100, in which a plurality of wafers W are accommodated, is placed; a scanner unit 45; and a control unit 46. The scanner unit 45 detects a first portion Wb1, a second portion Wb2, and a third portion Wb3 of an end surface Wb of a wafer W while maintaining a fixed state in which the FOUP 100 is placed on the placement unit 44 and the angle of the FOUP 100 around a vertical axis with respect to the support frame 43 is fixed. The control unit 46 determines whether each wafer W is normally accommodated in the FOUP 100 by using information of a first position of the first portion Wb1 and information of a second position of the second portion Wb2. The control unit 46 calculates the amount of deflection in the vertical direction of the wafer W normally stored in the FOUP 100 by using the information of the first position and / or the information of the second position, and information of the third position of the third portion Wb3.

Description

Loading Port

[0001] The present invention relates to a load port.

[0002] Load ports on which containers containing multiple wafers (hereinafter, "substrates") arranged vertically are placed have been known for some time. Many recent load ports have a mapping function for detecting the status of each substrate in the container. For example, a substrate loading / unloading device disclosed in Patent Document 1 (JP-A-2005-102626) has a load port-equivalent component including a placement unit on which a cassette (hereinafter, "container") is placed, a substrate detector, and a drive unit (referred to as a shutter drive mechanism in Patent Document 1). The substrate detector has a transmission-type optical sensor including a light irradiation unit and a light detection unit, and is driven to move vertically by the drive unit. The light irradiation unit and the light detection unit are disposed horizontally on opposite sides of the end of the substrate in the container near the substrate detector. When light irradiated from the light irradiation unit is blocked in a certain vertical region during vertical movement of the substrate detector, it is determined that a substrate is present in that region.

[0003] Patent Document 2 discloses a pitch measurement device that performs mapping of multiple substrates housed in a container, which is different from the load port described above. The pitch measurement device is configured to measure the amount of deflection of each substrate due to its own weight. More specifically, the pitch measurement device includes a photoelectric element, a scanning device, and a rotating base on which the container is placed. The photoelectric element includes a light emitter and a light receiver. The photoelectric element detects the substrate by emitting light to the substrates in the pod using the light emitter and receiving the light reflected from the substrate using the light receiver. In mapping, the scanning device performs multiple scanning operations, moving the photoelectric element from a predetermined upper end position to a predetermined lower end position. The rotating base changes the rotation angle of the container between one scanning operation and the next scanning operation. This detects the height positions of each substrate at multiple points around the rotating base. For each substrate, the amount of deflection is measured by calculating the difference between the height positions of the highest and lowest points.

[0004] JP 2001-7182 A

[0005] With the recent trend toward thinner substrates, the present inventors have been considering measuring the amount of deflection of substrates in load ports. One of the objectives is to utilize deflection information in the operational control of a substrate transport device that transports substrates in a container placed on a load port. However, in the substrate detector described in Patent Document 1, the light emitted from the light emitting means during vertical movement is blocked for a similarly long period of time whether the substrate is simply deflected or is housed in the container in an abnormal tilted state. As a result, the substrate detector cannot distinguish whether a substrate normally housed in the container is simply deflected or whether the substrate is housed in the container in an abnormal state. Therefore, it is considered to use the photoelectric element described in Patent Document 2 to detect the edge of the substrate. However, the load port described in Patent Document 1 does not allow the container to be rotated between one scanning operation and the next. Therefore, the invention described in Patent Document 2 cannot be directly applied to load ports.

[0006] An object of the present invention is to determine whether a substrate is normally accommodated in a container and to calculate the amount of deflection of the substrate without rotating the container.

[0007] A load port of a first invention is a load port comprising: a base portion having a fixed installation position; a placement portion attached to the base portion on which a container for containing a plurality of substrates arranged vertically is placed; a scanner portion configured to detect the plurality of substrates contained in the container; and a determination portion configured to make a determination regarding the state of each of the plurality of substrates detected by the scanner portion, wherein the scanner portion, while the container is placed on the placement portion and is maintained in a fixed state in which the angle of the container about a vertical axis relative to the base portion is fixed, detects the following in the direction of extension of each end face of the plurality of substrates: The device is configured to be able to detect specific first, second, and third parts of the end face that are arranged at a distance from each other, and the judgment unit uses information on a first position, which is the vertical position of the first part, and information on a second position, which is the vertical position of the second part, to judge whether each substrate is properly contained in the container, and calculates the amount of vertical deflection of a substrate among the plurality of substrates that is properly contained in the container using information on the first position, information on the second position, or both, and information on a third position, which is the vertical position of the third part.

[0008] In the present invention, the scanner unit can detect the vertical positions of the first, second, and third portions of the end face of each substrate while the container is fixed at a fixed angle relative to the base. The determination unit can then determine whether each substrate is properly accommodated in the container. Furthermore, the determination unit can calculate the amount of deflection of a substrate properly accommodated in the container. Therefore, it is possible to determine whether the substrate is properly accommodated in the container and calculate the amount of deflection of the substrate without rotating the container.

[0009] The load port of a second invention is the load port of the first invention, characterized in that the scanner unit has a first sensor configured to be able to detect the first portion, a second sensor configured to be able to detect the second portion and separate from the first sensor, a third sensor configured to be able to detect the third portion and separate from the first sensor and the second sensor, a support unit that supports the first sensor, the second sensor, and the third sensor, and a drive unit configured to be able to move and drive the support unit in a vertical direction.

[0010] In the present invention, the first sensor, the second sensor, and the third sensor can be moved simultaneously in the vertical direction. This allows the first position information, the second position information, and the third position information to be acquired simultaneously depending on the function of the determination unit. In this case, the operating time of the scanner unit can be shortened.

[0011] The load port of the third invention is characterized in that, in the first or second invention, when the container is in the fixed state, a first support portion for supporting each of the plurality of substrates within the container is arranged on one side of the center of the container in a predetermined container width direction perpendicular to the vertical direction, and a second support portion for supporting each of the plurality of substrates within the container is arranged on the other side of the center of the container in the container width direction, the first portion is arranged on the first support portion side of the center of the container in the container width direction, the second portion is arranged on the second support portion side of the center of the container in the container width direction, and the third portion is arranged between the first portion and the second portion in the container width direction.

[0012] In the present invention, the first portion located relatively close to the first support and the second portion located relatively close to the second support hardly deflect. Therefore, by using the first position information and the second position information, it is possible to accurately determine whether each substrate is located in the correct position within the container. Furthermore, because the portions located relatively far from the first and second support portions in the container width direction are prone to deflection due to their own weight, the third portion is prone to sagging more than the first and second portions. Therefore, by using the third position information and the first position information and / or the second position information, the amount of deflection of each substrate can be accurately calculated.

[0013] The load port of a fourth invention is the load port of the first or second invention, characterized in that the scanner unit has a reflective optical sensor including a light-emitting unit configured to emit detection light for detecting the end face and a light-receiving unit configured to sense the detection light reflected by the end face, and an angle adjustment unit configured to adjust the angle around a vertical axis of the optical axis of the detection light emitted from the light-emitting unit.

[0014] In the present invention, even when substrates of various shapes and / or sizes are handled on the load port, the edge of each substrate can be reliably detected by adjusting the angle of the optical axis around the vertical axis.

[0015] A fifth aspect of the load port is the fourth aspect of the present invention, characterized in that the plurality of substrates include a plurality of wafers which are semiconductor substrates, and the reflective optical sensor is arranged so that the optical axis is perpendicular to the end face of each of the plurality of substrates.

[0016] Wafers generally have a substantially circular cross section, and therefore a configuration in which the angle of the optical axis of the reflective optical sensor around the vertical axis is adjusted so that the optical axis is positioned substantially perpendicular to the end face is particularly effective in a load port that handles containers that house substrates, including wafers.

[0017] 1 is a schematic plan view of an EFEM equipped with a load port according to an embodiment of the present invention and its surroundings; (a) is a side cross-sectional view of a FOUP, and (b) is a rear view of the FOUP with the lid removed; (a) and (b) are views showing wafers stored in an abnormal state in the FOUP; (a) is a perspective view of the load port; (b) is a right side view of the load port; and (b) is a rear view of the load port. (a) and (b) are views showing the operation of the load port; (a) is a view showing the arrangement of a scanner unit, and (b) is a view showing portions of the edge surface of a wafer that are detected by each of a plurality of sensors; and (b) is a flowchart showing the judgment process for each wafer, which is a flowchart showing the entire mapping process.

[0018] An embodiment of the present invention will be described. For convenience of explanation, the directions shown in FIG. 1 are defined as the front-rear and left-right directions. More specifically, the direction in which an EFEM 1 (described later) and a processing device 6 (described later) are arranged is defined as the front-rear direction. In the front-rear direction, the EFEM 1 side is defined as the front side. In the front-rear direction, the processing device 6 side is defined as the rear side. The direction perpendicular to the front-rear direction, in which multiple load ports 4 are arranged, is defined as the left-right direction. The direction perpendicular to both the front-rear direction and the left-right direction is defined as the up-down direction. The up-down direction is a direction parallel to the vertical direction in which gravity acts.

[0019] (Schematic Configuration of Load Port and Its Surrounding Area) The schematic configuration of the load port 4 and its surrounding area according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic diagram of an EFEM 1 equipped with multiple load ports 4 and its surrounding area. "EFEM" is an abbreviation for "Equipment Front End Module." The EFEM 1 is a device for transporting wafers W between a FOUP 100 (described below) placed on each load port 4 and the processing device 6. The wafer W is, for example, a substantially circular semiconductor substrate. The diameter of the wafer W accommodated in the FOUP 100 is, for example, approximately 300 mm. The wafer W has an upper surface Wa1, a lower surface Wa2, and an end surface Wb (see FIGS. 2(a) and 2(b)). The upper surface Wa1 is a surface facing substantially upward. The lower surface Wa2 is a surface facing substantially downward. The end surface Wb is a surface located between the upper surface Wa1 and the lower surface Wa2 in the vertical direction. In this embodiment, the wafer W corresponds to the substrate of the present invention.

[0020] 1, the EFEM 1 includes a housing 2, a transfer robot 3, a plurality of load ports 4, and a control device 5. A processing device 6 is disposed behind the EFEM 1.

[0021] The EFEM 1 is installed at a predetermined position in, for example, a semiconductor factory. The EFEM 1 transfers wafers W between a FOUP 100 placed on a load port 4 and a processing device 6 using a transfer robot 3 arranged in a transfer space 9 within a housing 2. "FOUP" is an abbreviation for "Front-Opening Unified Pod." The FOUP 100 is a container that can accommodate multiple wafers W arranged vertically. The FOUP 100 is transferred by, for example, a FOUP transfer device (not shown). The FOUP 100 is transferred between the FOUP transfer device and the load port 4.

[0022] The housing 2 is a box-shaped member having a transfer space 9 in which the wafers W are transferred. The transfer space 9 is separated from an external space 10 mainly by the housing 2. The external space 10 is a space outside the EFEM 1 and the processing device 6. A plurality of load ports 4 are connected to the front end of the housing 2. A load lock chamber 7 (described later) of the processing device 6 is connected to the rear end of the housing 2. The transfer robot 3 is configured to be able to transfer the wafers W between the FOUP 100 and the load lock chamber 7.

[0023] The multiple load ports 4 are arranged, for example, side by side in the left-right direction. The multiple load ports 4 are attached to the front end of the housing 2. Each load port 4 is configured to receive a FOUP 100. Each load port 4 is configured to attach and detach a lid 102 (described below) to a FOUP body 101 (described below) of the FOUP 100. Each load port 4 is configured to be able to perform mapping of the multiple wafers W accommodated in the FOUP body 101. The configuration of the load port 4 will be described in more detail below.

[0024] The control device 5 is electrically connected to a control unit (not shown) of the transfer robot 3, a control unit 46 (described later) of the load port 4, and a control unit (not shown) of the processing device 6. The control device 5 is configured to communicate with these control units. As shown in FIG. 1, the control device 5 may also be electrically connected to a higher-level host computer 200.

[0025] The processing apparatus 6 is an apparatus that performs a predetermined process on the wafer W. The predetermined process may be, for example, a process performed in a vacuum chamber (such as sputtering or dry etching), or may be another process. As shown in FIG. 1 , the processing apparatus 6 includes, for example, a load lock chamber 7 and a processing chamber 8. The load lock chamber 7 is a room in which the wafer W is temporarily placed on standby. The load lock chamber 7 is disposed between the transfer space 9 and the processing chamber 8. The processing chamber 8 is a room in which the predetermined process is performed on the wafer W.

[0026] (FOUP) An example of the configuration of a FOUP 100 will be described with reference to Figures 2(a) and 2(b). Figure 2(a) is a side cross-sectional view of the FOUP 100. Figure 2(b) is a rear view of the FOUP 100 with the lid 102 removed. The front, back, left, right, up and down directions shown in Figures 2(a) and 2(b) are directions when the FOUP 100 is placed on the load port 4 for the sake of convenience of explanation.

[0027] The FOUP 100 is a container having a generally rectangular parallelepiped shape. The FOUP 100 is configured to be able to accommodate, for example, 25 wafers W. The number of wafers W that the FOUP 100 can accommodate is not limited to this. As shown in FIGS. 2( a) and 2(b) , the FOUP 100 has a FOUP body 101 and a lid 102. The FOUP body 101 is a generally rectangular parallelepiped member. The FOUP body 101 has an outer wall portion 111, an opening portion 112, and a plurality of support portions 113 (see FIG. 2(b) ). The outer wall portion 111 is disposed so as to surround the internal space of the FOUP 100. The opening portion 112 is disposed at the rear end portion of the FOUP body 101. The opening portion 112 has an opening 112a that is generally rectangular when viewed from the rear.

[0028] The multiple support members 113 are configured to support the multiple wafers W in a substantially horizontal position. Each of the multiple support members 113 is, for example, a substantially flat plate-shaped member. Each support member 113 extends longitudinally in the front-rear direction. The thickness direction of each support member 113 is substantially parallel to the up-down direction. Each left-right end of the wafer W is placed on the upper surface of one of the support members 113. As shown in FIG. 2B , the multiple support members 113 are arranged in a substantially rectangular parallelepiped space surrounded by the FOUP main body 101. Each of the multiple support members 113 is fixed, for example, to the inner surface of one of both left-right end portions of the outer wall member 111. Hereinafter, for convenience of explanation, the multiple support members 113 fixed to the inner surface of the left end portion of the outer wall member 111 will be referred to as multiple support members 113L. The multiple support members 113L are arranged to the left of the left-right center of the FOUP 100. The multiple support portions 113L are arranged side by side in the vertical direction. Each of the multiple support portions 113L corresponds to a second support portion of the present invention. Of the multiple support portions 113, the multiple support portions 113 fixed to the inner surface of the right end portion of the outer wall portion 111 will be referred to as multiple support portions 113R below for ease of explanation. The multiple support portions 113R are arranged to the right of the center of the FOUP 100 in the left-right direction. The multiple support portions 113R are arranged side by side in the vertical direction. Each of the multiple support portions 113R corresponds to a first support portion of the present invention.

[0029] The number of the plurality of support portions 113L is the same as the number of the plurality of support portions 113R. That is, the plurality of support portions 113L and the plurality of support portions 113R correspond one-to-one. One corresponding support portion 113L and one corresponding support portion 113R are arranged at approximately the same position in the vertical direction. Such a pair of support portion 113L and support portion 113R is arranged to support one wafer W. The space for supporting one wafer W is called a slot. That is, the FOUP 100 has multiple slots.

[0030] The lid 102 is configured to open and close the opening 112a. The lid 102 is attached to and detached from the FOUP body 101 by the load port 4, as will be described later.

[0031] (Wafer in FOUP) To facilitate the following explanation, the state of wafers W accommodated in the FOUP 100 will be briefly described with reference to FIGS. 2(a) to 3(b). FIGS. 3(a) and 3(b) are views showing wafers W accommodated in an abnormal state in the FOUP 100. FIG. 3(a) is a view showing a wafer W in a cross state, which will be described later. FIG. 3(b) is a view showing a wafer W in a double state, which will be described later. In FIGS. 3(a) and 3(b), only one or more wafers W accommodated in one slot out of the multiple slots are shown.

[0032] When each wafer W is stored in the FOUP 100 in a normal state, as shown in FIG. 2( b), multiple wafers W are placed on multiple pairs of wafers 113L and 113R. This state of wafers W is called a single state. On the other hand, wafers W may be stored in the FOUP 100 in an abnormal state. For example, as shown in FIG. 3( a), a wafer W may be placed on a certain support 113L and a support 113R that is positioned vertically offset from the support 113L. This state of wafers W is called a cross state. Alternatively, as shown in FIG. 3( b), two wafers W may be stored in the same slot while overlapping vertically. This state of two wafers W is called a double state.

[0033] As shown by the two-dot chain line in Fig. 2(a) and the two-dot chain line in Fig. 2(b), each wafer W in the single state may be warped. Details will be described later.

[0034] (Load Port) The configuration of the load port 4 will be described with reference to Figures 4 to 6. Figure 4 is a perspective view of the load port 4. Figure 5 is a right side view of the load port 4. Figure 6 is a rear view of the load port 4.

[0035] The load port 4 is configured to remove the lid 102 of the FOUP 100 from the FOUP body 101 and perform mapping of the multiple wafers W accommodated in the FOUP body 101. As shown in Figures 4 to 6, the load port 4 has, for example, a base 41, a door mechanism 42, a support frame 43, a placement unit 44, a scanner unit 45, and a control unit 46.

[0036] The base 41 is a substantially flat member. The base 41 has a substantially rectangular shape when viewed from the front-to-rear direction. The base 41 is arranged to extend in the up-and-down direction. The base 41 is fixed to the EFEM 1. The base 41 is part of a partition wall that separates the transfer space 9 from the external space 10. The base 41 has a substantially rectangular opening 41a. The opening 41a is arranged in the upper part of the base 41. The opening 41a is large enough to allow the lid 102 of the FOUP 100 to pass through in the front-to-rear direction. The opening 41a is opened and closed by a door main body 50, which will be described later.

[0037] The door mechanism 42 is configured to enable the lid 102 to be attached to and detached from the FOUP body 101. As shown in Figures 4 and 5 , the door mechanism 42 includes, for example, a door body 50, a plurality of suction holding portions 51, a plurality of latch keys 52, a door support portion 53, a guide rail 54, a lifting block 55, a guide rail 56, a motor 57, and a motor 58.

[0038] The door body 50 is a plate-shaped member. When viewed from the front and rear, the door body 50 has a substantially rectangular shape. The door body 50 is supported by a door support portion 53. The plurality of suction holding portions 51 are configured to suction and hold the lid 102 to the front surface of the door body 50. The plurality of suction holding portions 51 are connected to a vacuum pump (not shown). When the vacuum pump operates, negative pressure is generated inside the piping, and the lid 102 is suctioned and held to the door body 50. The latch key 52 is configured to unlock and lock the lid 102 of the FOUP 100. The latch key 52 has a size and shape that allows it to be inserted into a keyhole (not shown) of the lid 102. The latch key 52 is driven by an opening / closing mechanism (not shown) to unlock or lock the lid 102 attached to the FOUP body 101.

[0039] The door support portion 53 is a member that supports the door body 50. The door support portion 53 is disposed outside the movable range of the transport robot 3 in the transport space 9. The door body 50 is fixed to the door support portion 53 by a fixture (not shown). The door support portion 53 extends in the vertical direction. The door support portion 53 is supported by a guide rail 54 so as to be movable in the front-rear direction. The door support portion 53 is driven to move in the front-rear direction by a motor 57. The door support portion 53 moves in the front-rear direction to move the door body 50 between a closed position (see FIG. 7B) and an open position (see FIG. 8A). The closed position is the position of the door body 50 when the door body 50 blocks the opening 41a of the base 41. The open position is a position rearward of the closed position and is the position of the door body 50 when the door body 50 opens the opening 41a. The guide rail 54 is a member that guides the door support portion 53 in the front-rear direction. The guide rail 54 is provided on the lift block 55. The guide rail 54 extends in the front-rear direction.

[0040] The lifting block 55 is a member for moving the door main body 50 in the up and down direction. The lifting block 55 movably supports the door support portion 53 by means of a guide rail 54. The lifting block 55 is guided in the up and down direction along a guide rail 56. The lifting block 55 is driven to move in the up and down direction by a motor 58. By moving the lifting block 55 in the up and down direction, the door main body 50 is moved between the above-mentioned open position (see FIG. 8( a)) and a retracted position (see FIG. 8( b)) that is lower than the open position. The guide rail 56 is a member for guiding the lifting block 55 in the up and down direction. The guide rail 56 is attached to, for example, the base 41. The guide rail 56 extends in the up and down direction.

[0041] The motor 57 is configured to drive the door support portion 53 to move in the front-rear direction. The motor 57 is, for example, a known stepping motor driven by a pulse signal. The motor 57 is configured to be able to control the position of the door support portion 53 in the front-rear direction. The motor 58 is configured to drive the lifting block 55 to move in the up-down direction. The motor 58 is, for example, a known stepping motor driven by a pulse signal. The motor 58 is configured to be able to control the position of the door support portion 53 in the up-down direction. In other words, the motor 58 is also configured to be able to control the position of a detection portion 61 (see FIG. 5 , etc.), which will be described later, in the up-down direction.

[0042] The support frame 43 is a member for supporting the mounting portion 44. The support frame 43 has a substantially rectangular shape when viewed from the top-bottom direction. The support frame 43 is fixed to the base 41. That is, the installation position of the support frame 43 is fixed. The support frame 43 is disposed so as to protrude forward from a midpoint of the base 41 in the top-bottom direction. The support frame 43 corresponds to the base portion of the present invention.

[0043] The placement unit 44 is a platform-like member on which the FOUP 100 is placed. The placement unit 44 is supported by the support frame 43. The placement unit 44 is configured to be movable in the front-to-rear direction relative to the support frame 43. The placement unit 44 has a positioning pin 44a and a locking claw 44b. The positioning pin 44a is a member for positioning the FOUP 100. The locking claw 44b is a member for fixing and releasing the FOUP 100 to the placement unit 44. The placement unit 44 is configured to be movable by a drive mechanism (not shown) between a predetermined transfer position and a lid opening / closing position behind the transfer position. The transfer position is the position of the placement unit 44 when the FOUP 100 can be transferred to and from a FOUP transport device (not shown). The placement unit 44 may also be configured to be rotatable around a vertical axis.

[0044] The scanner unit 45 is for detecting a plurality of wafers W. The scanner unit 45 is disposed, for example, in the transfer space 9. As shown in FIG. 6 , the scanner unit 45 includes a detection unit 61, a support member 62, and a front-rear drive unit 63.

[0045] The detector 61 is for detecting a plurality of wafers W. The detector 61 is disposed, for example, above the door body 50. The detector 61 is supported by a support member 62. The detector 61 is movable between a predetermined standby position (see FIGS. 7( a) and 7(b)) and a scan position (see FIG. 8(a)) by a front-rear drive unit 63. The scan position is, for example, a position where at least a part of the detector 61 protrudes forward from the door body 50. The structure of the detector 61 will be described in more detail below.

[0046] The support member 62 is a member that supports the detection unit 61. As shown in FIG. 6 , the support member 62 is a generally C-shaped member when viewed from the front-rear direction. The support member 62 has, for example, an upper end 62a to which the detection unit 61 is fixed, an extension portion 62b extending downward from the left end of the upper end 62a, and a lower end 62c extending rightward from the lower end of the extension portion. In this embodiment, the support member 62 opens to the right. However, this is not limited thereto, and the support member 62 may open to the left. The support member 62 is disposed, for example, so as to bypass the door main body 50. The lower end 62c of the support member 62 may be swingably supported, for example, by the door support portion 53. The swing axis direction of the support member 62 may be, for example, substantially parallel to the left-right direction. The support member 62 may be swingably driven, for example, by a front-rear drive unit 63.

[0047] The front-rear drive unit 63 drives the detection unit 61 to move in the front-rear direction. The front-rear drive unit 63 may have, for example, a motor (not shown). Alternatively, the front-rear drive unit 63 may have, for example, an air cylinder (not shown). The front-rear drive unit 63 may drive the support member 62 to swing, for example, to move the detection unit 61 in the front-rear direction. The front-rear drive unit 63 is electrically connected to the control unit 46.

[0048] The control unit 46 includes a CPU, ROM, and RAM (not shown). The control unit 46 controls each mechanism of the load port 4 by the CPU in accordance with a program stored in the ROM. The control unit 46 also communicates with the control device 5 of the EFEM 1, the host computer 200, etc. The control unit 46 corresponds to a determination unit in the present invention.

[0049] Additionally, the load port 4 may have a replacement unit (not shown) that replaces the gas inside the FOUP 100. The load port 4 may have a clamping mechanism (not shown) that presses the FOUP body 101 against the base 41. Details of these will be omitted.

[0050] (Basic Operation of Load Port) The basic operation of the load port 4 having the above configuration will be described with reference to Figures 7(a) to 8(b). Figures 7(a) to 8(b) are right side views of the load port 4 in operation. Here, the operation of the load port 4 from when the FOUP 100 is placed on the placement unit 44 until the multiple wafers W are detected at least once by the scanner unit 45 will be described.

[0051] First, the FOUP 100 is placed on the placement unit 44 (see FIG. 7( a)). The FOUP 100 is positioned by the positioning pins 44a and secured to the placement unit 44 by the locking claws 44b. Next, the control unit 46 moves the placement unit 44 from the delivery position (see FIG. 7( a)) to the lid opening / closing position (FIG. 7( b)). This causes each of the multiple latch keys 52 (see FIG. 4) to approach the FOUP 100 relatively and be inserted into a corresponding one of the multiple keyholes formed in the lid 102. When the placement unit 44 is in the lid opening / closing position, it neither moves nor rotates. In other words, the angle of the FOUP 100 around the vertical axis relative to the support frame 43 is maintained fixed. For ease of explanation, this state of the FOUP 100 is referred to as the fixed state. When the FOUP 100 is in a fixed state, the width direction of the opening 112a (the container width direction of the present invention) is approximately parallel to the left-right direction. The right side corresponds to one side in the container width direction of the present invention. The left side corresponds to the other side in the container width direction of the present invention.

[0052] After the FOUP 100 is placed on the placement unit 44, the control unit 46 may control a replacement unit (not shown) to perform a purge process to replace the gas inside the FOUP 100. The control unit 46 may control a clamping mechanism (not shown) to press the rear end surface of the FOUP body 101 against the base 41.

[0053] Next, the control unit 46 controls a vacuum pump (not shown) to suck and hold the lid 102 to the suction holding portion 51 of the door body 50. The control unit 46 controls the operation of the latch key 52 to unlock the lid 102. The control unit 46 controls the motor 57 to move the door support portion 53 rearward (see the rightward arrow in FIG. 8( a)). This moves the door body 50 from a predetermined closed position (see FIG. 7( b)) to an open position (see FIG. 8( a)). As a result, the lid 102 is removed from the FOUP body 101.

[0054] Next, the control unit 46 controls the front-rear drive unit 63 to move the detection unit 61 from the standby position (see FIG. 7B) to the scan position (see FIG. 8A). This operation is a preparatory operation for the detection unit 61 to detect a plurality of wafers W.

[0055] Next, the control unit 46 controls the motor 58 to move the door body 50 from the open position (see FIG. 8( a)) to the retracted position (see FIG. 8( b)). Accordingly, the detection unit 61 can detect the plurality of wafers W arranged vertically in order from the top. The control unit 46 performs a mapping process based on the position information of the plurality of wafers W detected by the detection unit 61. In this embodiment, the mapping process is a process that includes determining whether the plurality of wafers W are properly accommodated in the FOUP body 101. The mapping process will be described in detail later.

[0056] After the mapping process is completed, the transfer robot 3 starts transferring the wafers W between the FOUP 100 and the processing device 6. The processing device 6 sequentially performs predetermined processing on some or all of the wafers W. The processed wafers W are returned into the FOUP 100 by the transfer robot 3.

[0057] After all the wafers W have been returned into the FOUP 100, the control unit 46 causes the door mechanism 42 and the like to perform the reverse operation of that performed when opening the lid 102. That is, the control unit 46 moves the door body 50 from the retracted position to the open position, and then from the open position to the closed position. Next, the control unit 46 controls the operation of the latch key 52 to lock the lid 102. The control unit 46 releases the suction of the lid 102 to the door body 50. Thereafter, the control unit 46 moves the placement unit 44 from the lid open / close position to the transfer position. In this manner, a series of processes from when the FOUP 100 is transferred to the load port 4 until it is ready for removal is completed.

[0058] (Wafer Deflection) In recent years, wafers W have been further thinned. The thickness of a conventional wafer W is, for example, 0.775 mm. In recent years, the thickness of wafers W has tended to be significantly thinner, ranging from 0.1 mm to 0.2 mm. Accordingly, deflection of the wafer W, mainly due to its own weight, has become apparent. The deflection patterns of the wafer W include, for example, the following two patterns. As a first pattern, as shown by the two-dot chain line in FIG. 2( a), the rear end portion of the wafer W may sag. As a second pattern, as shown by the two-dot chain line in FIG. 2( b), the entire central portion in the left-right direction may sag. In either pattern, it is understood that the portion of the wafer W that is not supported by the support portion 113 is deflected due to its own weight.

[0059] In light of the above, there is a need to calculate the amount of deflection of the wafer W during the mapping process in the load port 4. For example, JIS No. 3177757 describes an apparatus for calculating the amount of deflection of a substrate (not shown) in a container (not shown). However, this apparatus requires that the angular position of the container about the vertical axis be changed during the mapping process. In the load port 4, when the placement unit 44 is in the lid open / close position (see FIG. 7B ), even if an attempt is made to rotate the placement unit 44 during the mapping process, the FOUP 100 will interfere with the base 41. Therefore, in this embodiment, the load port 4 has the following configuration in order to measure the amount of deflection of the wafer W in the FOUP 100 without rotating the FOUP 100. More specifically, the scanner unit 45 has the following configuration.

[0060] (Detailed Configuration of Scanner Unit) The detailed configuration of the scanner unit 45 will be described with reference to FIGS. 9( a) and 9(b). FIG. 9(a) is a plan view schematically showing the arrangement of the scanner unit 45. FIG. 9(b) is a view showing portions of the edge Wb of the wafer W that are detected by each of a plurality of sensors 72, which will be described later. The direction shown in FIG. 9(b) is the same as the direction shown in FIG. 2(b). It should be noted that the left-right direction in this embodiment is opposite to the left-right direction on the paper in FIGS. 9(a) and 9(b).

[0061] As described above, the scanner unit 45 has the detection unit 61, the support member 62, and the front-rear drive unit 63. As shown in Fig. 9A, the detection unit 61 has, for example, a main body 71 and three sensors 72.

[0062] The main body 71 is a member to which three sensors 72 are attached. The main body 71 is, for example, a roughly rod-shaped member. The main body 71 extends, for example, in a direction substantially parallel to the left-right direction. The main body 71 supports the three sensors 72. The main body 71 corresponds to the support portion of the present invention. For example, the left end of the main body 71 is fixed to the support member 62 by, for example, a fixing tool (not shown). Alternatively, the main body 71 and the support member 62 may be fixed to each other by a different means or may be formed from the same member.

[0063] As shown in FIG. 9A , the main body 71 has, for example, a long portion 71a, a protruding portion 71b, and a protruding portion 71c. The long portion 71a is, for example, a substantially rod-shaped portion. The long portion 71a extends, for example, in a direction substantially parallel to the left-right direction. The long portion 71a is disposed behind the FOUP 100 on the mounting portion 44. In the left-right direction, the center position of the long portion 71a is substantially equal to the center position of the mounting portion 44 (i.e., the center position of the FOUP 100 on the mounting portion 44). The protruding portion 71b is, for example, a substantially rod-shaped portion. The protruding portion 71b is shorter than the long portion 71a. The protruding portion 71b protrudes forward, for example, from the right end of the long portion 71a. The protruding portion 71c is, for example, a substantially rod-shaped portion. The protruding portion 71c has a length substantially equal to that of the protruding portion 71b in the front-rear direction. The protruding portion 71c protrudes forward from, for example, the left end portion of the long portion 71a.

[0064] Each of the three sensors 72 is configured to be able to detect the edge Wb of the wafer W. Each sensor 72 is, for example, a known reflective laser sensor. That is, each sensor 72 is configured to be able to emit and detect, as detection light, a laser beam for detecting the edge Wb. The reflective laser sensor corresponds to a reflective optical sensor of the present invention. It is preferable that the three sensors 72 are arranged at approximately equal positions in the vertical direction.

[0065] Each sensor 72 includes a light-emitting unit 81 and a light-receiving unit 82. The light-emitting unit 81 includes a light-emitting element (not shown) capable of emitting laser light (see the two-dot chain arrow in FIG. 9A). The light-emitting unit 81 is positioned to emit the laser light in a direction that is substantially horizontal and perpendicular to the end face Wb. In other words, the optical axis A of the light-emitting unit 81 is positioned substantially horizontal. The optical axis A of the light-emitting unit 81 is also positioned to be substantially perpendicular to a portion of the end face Wb of the wafer W in the FOUP 100. The shape of the laser beam may be, for example, substantially circular. Alternatively, the beam shape may be a shape other than substantially circular, such as an ellipse or a substantially rectangular shape. The vertical length of the beam is preferably smaller than, for example, the thickness of the wafer W (i.e., the designed vertical length of the end face Wb). The light-receiving unit 82 includes a light-receiving element (not shown) capable of detecting the laser light (see the two-dot chain arrow in FIG. 9A). The light receiving section 82 is disposed so as to sense the laser light reflected by the end face Wb.

[0066] The scanner unit 45 preferably includes multiple angle adjustment units 83. The multiple angle adjustment units 83 are configured to independently adjust the angles of the optical axes A of the multiple sensors 72 around the vertical axis. Each angle adjustment unit 83 may include, for example, a screw (not shown) for fixing the sensor 72 to the main body 71. The angle of the sensor 72 around the vertical axis may be changeable when the screw is loosened, and the sensor 72 may be fixed to the main body 71 by tightening the screw. Alternatively, the angle adjustment unit 83 may include, for example, a rotation shaft (not shown), a gear (not shown), and a knob (not shown). The rotation shaft may support the sensor 72 rotatably around the vertical axis. The gear may be coaxial with the rotation shaft and fixed to the rotation shaft. The knob may include a member that meshes with the gear. The knob may be configured to be turnable by an operator. Rotating the knob may gradually rotate the sensor 72 around the vertical axis via the gear. Alternatively, the angle adjustment unit 83 may have a motor (not shown) including a rotation shaft instead of a knob, for example. This allows the angle of the optical axis A about the vertical axis to be adjusted by the operation of the motor. Alternatively, the scanner unit 45 may have any angle adjustment unit 83 that can adjust the angle of the optical axis A of each sensor 72 about the vertical axis.

[0067] An example of the arrangement positions of the three sensors 72 will be described. Assume that the placement section 44 on which a FOUP is placed is in the lid open / close position (see FIG. 7B ). As shown by the dashed-dotted line in FIG. 9B , when viewed from the front-to-rear direction, an imaginary line extending vertically through the center of the FOUP 100 in the left-to-right direction is defined as an imaginary center line LC. As shown by the dashed-dotted line in FIG. 9B , an imaginary line extending vertically through the left ends of the multiple support sections 113R is defined as a first right-side line L1R. An imaginary line extending vertically through the right ends of the multiple support sections 113L is defined as a first left-side line L1L. An imaginary line extending vertically through a position exactly midway between the imaginary center line LC and the first right-side line L1R in the left-to-right direction is defined as a second right-side line L2R. An imaginary line extending in the up-down direction and passing through a position exactly midway between the imaginary center line LC and the first left straight line L1L in the left-right direction is defined as a second left straight line L2L.

[0068] As shown in FIG. 9A, the three sensors 72 include a first sensor 73, a second sensor 74, and a third sensor 75. The first sensor 73 is attached to, for example, the front end of the protrusion 71b. The optical axis A1 of the first sensor 73 is disposed so as to be substantially perpendicular to a first portion Wb1 (see FIGS. 9A and 9B), which is a part of the edge Wb of the wafer W. The first portion Wb1 is located rearward of the center of the wafer W in the front-rear direction. The position of the first portion Wb1 will be described in more detail below.

[0069] The second sensor 74 is attached to, for example, the front end of the protrusion 71c. The optical axis A2, which is the optical axis A of the second sensor 74, is disposed so as to be substantially perpendicular to the second portion Wb2 (see FIGS. 9A and 9B). The second portion Wb2 is a part of the end face Wb of the wafer W and is a separate portion from the first portion Wb1. The second portion Wb2 is located rearward of the center of the wafer W in the front-rear direction. The second portion Wb2 is disposed at a position separated from the first portion Wb1 in the extension direction of the end face Wb (in this embodiment, the circumferential direction of the wafer W). The position of the second portion Wb2 will be described in more detail below.

[0070] The third sensor 75 is attached, for example, to the center of the elongated portion 71a in the left-right direction. In other words, the third sensor 75 is disposed at a position approximately in the center between the protrusions 71b and 71c in the left-right direction. The optical axis A3, which is the optical axis A of the third sensor 75, is disposed so as to be approximately perpendicular to the third portion Wb3 (see FIGS. 9A and 9B). The third portion Wb3 is a part of the end surface Wb of the wafer W and is separate from both the first portion Wb1 and the second portion Wb2. The third portion Wb3 is located at the rear end of the wafer W. The third portion Wb3 is disposed at a position separated from both the first portion Wb1 and the second portion Wb2 in the extending direction of the end surface Wb. The position of the third portion Wb3 will be described in more detail below.

[0071] The positions of the first portion Wb1, the second portion Wb2, and the third portion Wb3 in the left-right direction will be described in more detail. As shown in FIG. 9B, the first portion Wb1 is located to the right of the imaginary center line LC. It is preferable that the first portion Wb1 be located to the left of the first right-side straight line L1R (in other words, on the inside in the left-right direction). It is even more preferable that the first portion Wb1 be located between the first right-side straight line L1R and the second right-side straight line L2R in the left-right direction. In other words, the first portion Wb1 is located near the support portion 113R in the left-right direction. Therefore, the first portion Wb1 is a portion of the edge surface Wb of the wafer W that is less likely to bend. The second portion Wb2 is located to the left of the imaginary center line LC. More specifically, it is preferable that the second portion Wb2 be located to the right of the first left-side straight line L1L (in other words, on the inside in the left-right direction). It is more preferable that the second portion Wb2 be disposed between the first left straight line L1L and the second left straight line L2L in the left-right direction. That is, the second portion Wb2 is disposed near the support portion 113L in the left-right direction. Therefore, like the first portion Wb1, the second portion Wb2 is a portion of the edge surface Wb of the wafer W that is less likely to bend. The third portion Wb3 is disposed, for example, between the second right straight line L2R and the second left straight line L2L in the left-right direction. It is more preferable that the third portion Wb3 be disposed, for example, on the imaginary center line LC. That is, the third portion Wb3 is disposed farther from both the support portion 113R and the support portion 113L in the left-right direction. Therefore, the third portion Wb3 is a portion of the edge surface Wb of the wafer W that is more likely to sag under its own weight than the first portion Wb1 and the second portion Wb2.

[0072] (Mapping Process) Next, the mapping process in the load port 4 will be described with reference to Figs. 10 and 11. Fig. 10 is a flowchart showing the entire mapping process. Fig. 11 is a flowchart showing the determination process for each wafer W.

[0073] The initial state is as follows: A FOUP 100 containing a plurality of wafers W is placed on the placement unit 44. The placement unit 44 is located in the lid open / close position. The lid 102 of the FOUP 100 is opened by the door mechanism 42. The door body 50 is located in the open position (see FIG. 8(a)). The detection unit 61 is located in the scan position (see FIG. 8(a)).

[0074] First, the control unit 46 scans the first sensor 73 (step S101 shown in FIG. 10 ). More specifically, the control unit 46 controls the motor 58 to move the door support 53 and the detection unit 61 together in the vertical direction. The control unit 46 moves the detection unit 61, for example, from a predetermined upper end position to a predetermined lower end position. The vertical length of each step (step length) taken by the detection unit 61 during its movement is preferably shorter than the vertical length of the optical axis A of each sensor 72. The control unit 46 calculates vertical position information of the detection unit 61 using information on the step length and information on the number of pulse signals sent to the motor 58. When the first sensor 73 detects the detection light, it sends a detection signal to the control unit 46 indicating that the first portion Wb1 has been detected. The control unit 46 associates the vertical position information of the detection unit 61 with information on the detection signal from the first sensor 73 and stores the information.

[0075] After completing the scan with the first sensor 73, the control unit 46 scans the second sensor 74 (step S102). The control unit 46 controls, for example, the motor 58 to return the detection unit 61 to the upper end position and then move the detection unit 61 back to the lower end position. When the second sensor 74 senses the detection light, it sends a detection signal indicating that the second portion Wb2 has been detected to the control unit 46. The control unit 46 associates and stores information about the vertical position of the detection unit 61 with information about the detection signal from the second sensor 74. Alternatively, when returning the detection unit 61 from the lower end position to the upper end position, the control unit 46 may also associate and store information about the vertical position of the detection unit 61 with information about the detection signal from the second sensor 74.

[0076] After completing the scan with the second sensor 74, the control unit 46 executes a scan with the third sensor 75 (step S103). The control unit 46 moves the detection unit 61, as in steps S101 and S102. When the third sensor 75 senses the detection light, it sends a detection signal indicating that the third portion Wb3 has been detected to the control unit 46. The control unit 46 associates and stores information about the vertical position of the detection unit 61 with information about the detection signal from the third sensor 75.

[0077] Next, the control unit 46 sequentially performs a determination process (details of which will be described later) for each wafer W, including a process for calculating the amount of deflection. More specifically, the control unit 46 inputs, for example, 1 into a predetermined variable N (step S104) and performs a determination process for the wafer W accommodated in the first slot (step S105). The control unit 46 determines whether the determination process for all wafers W has been completed (step S106). If there is a wafer W for which the determination process has not yet been performed (step S106: No), the control unit 46 adds, for example, 1 to the variable N (step S107). As a result, the control unit 46 performs a determination process for the wafer W next to the wafer W for which the determination was previously completed (i.e., the wafer W associated with the Nth slot) (step S105). After the determination process for all wafers W has been completed (step S106: Yes), the control unit 46 terminates the mapping process.

[0078] While the mapping process is being performed, the mounting unit 44 does not move or rotate. That is, the fixed state described above is maintained while the mapping process is being performed. While the fixed state is maintained, the scanner unit 45 detects the first portion Wb1, the second portion Wb2, and the third portion Wb3 of each of the multiple wafers W.

[0079] (Determination Process) The determination process for each wafer W will be described with reference to Fig. 11. In summary, the control unit 46 determines whether the wafer W to be determined (the wafer W associated with the Nth slot described above) is properly accommodated in the FOUP 100, and then calculates the amount of deflection of the wafer W.

[0080] First, the control unit 46 determines whether or not the wafer W to be determined is present (step S201 shown in FIG. 11 ). More specifically, the control unit 46 calculates, for example, the vertical center position of the first portion Wb1 of the wafer W based on the vertical position information of the detection unit 61 and the detection signal from the first sensor 73. For convenience of explanation, this center position is referred to as the first position. The control unit 46 also calculates the vertical center position of the second portion Wb2 of the wafer W based on the vertical position information of the detection unit 61 and the detection signal from the second sensor 74. For convenience of explanation, this center position is referred to as the second position. The control unit 46 determines, for example, whether at least one of the first position and the second position of the wafer W falls within a predetermined set range. The predetermined set range is a range of vertical positions corresponding to the wafer W to be determined. For example, the upper and lower limit values ​​of this set range are input in advance to the control unit 46 or another computer device when the load port 4 is set up. Alternatively, the upper and lower limits may be pre-stored in the control unit 46 or another computer device, for example, by predetermined teaching. When at least one of the first and second positions of the wafer W falls within the set range, the control unit 46 determines that the wafer W to be evaluated is present (step S201: Yes) and proceeds to the next step. On the other hand, when a wafer W is not accommodated in the Nth slot, neither the first portion Wb1 nor the second portion Wb2 is detected within the set range. When neither the first position nor the second position falls within the set range, the control unit 46 determines that the wafer W associated with the Nth slot is not present (step S201: No). In this case, the control unit 46 determines that a "substrate is not present" (step S202). When a "substrate is not present" determination is made, the control unit 46 terminates the evaluation process for the wafer W.

[0081] The definitions of the first position and the second position may be different from those described above. For example, the control unit 46 may treat the position where the upper end of the first portion Wb1 is detected as the first position, and the position where the upper end of the second portion Wb2 is detected as the second position. Alternatively, the control unit 46 may treat the position where the lower end of the first portion Wb1 is detected as the first position, and the position where the lower end of the second portion Wb2 is detected as the second position. The above setting range is required to be set in advance in accordance with the definitions of the first position and the second position.

[0082] In the next step, the control unit 46 determines whether the wafer W to be determined is in a cross state. The control unit 46 determines whether the difference (absolute value) between the first position and the second position of the wafer W is greater than a predetermined reference value (step S203). The reference value is a threshold value for determining whether the wafer W is accommodated in the FOUP 100 in an inclined state. The reference value is input to the control unit 46 or another computer device in advance when the load port 4 is set up. Alternatively, the reference value may be pre-stored in the control unit 46 or another computer device, for example, by predetermined teaching. The reference value may be, for example, half the value of the vertical pitch of the multiple slots in the FOUP 100. If the difference value is greater than the reference value (step S203: Yes), the control unit 46 performs a cross determination to determine that the state of the wafer W is in a cross state (step S204). If a cross determination is performed, the control unit 46 terminates the determination process for the wafer W.

[0083] If the difference value is equal to or less than the reference value (step S203: No), the control unit 46 then determines whether the wafer W is in a double state. More specifically, the control unit 46 acquires information about the vertical length of the wafer W (i.e., the thickness of the wafer W) based on the number of times the wafer W is detected by the detection unit 61 during scanning by one or more sensors 72. The control unit 46 may, for example, use information about the vertical length of the first portion Wb1 as information about the thickness of the wafer W. The control unit 46 uses this information to determine whether the thickness of the wafer W is greater than a predetermined reference thickness (step S205). The reference thickness is a threshold value for determining whether two or more wafers W are accommodated in the same slot of the FOUP 100. Like the reference value, the reference thickness value is also stored in advance in the control unit 46 or another computer device. The reference thickness value may be, for example, 1.5 times the specified thickness of the wafer W. Note that the reference thickness value is not limited to this. If the thickness of the wafer W is greater than the reference thickness (step S205: Yes), the control unit 46 performs a double determination to determine that the state of the wafer W is a double state (step S206). If a double determination is performed, the control unit 46 ends the determination process for the wafer W.

[0084] If the thickness of the wafer W is equal to or less than the reference thickness (step S205: No), the control unit 46 performs a single determination (step S207). The single determination indicates that the wafer W is properly accommodated in the FOUP 100 and is in a single state. Furthermore, the control unit 46 calculates the amount of deflection of the wafer W (step S207). More specifically, the control unit 46 calculates the vertical center position of the third portion Wb3 of the wafer W based on the vertical position information of the detection unit 61 and the detection signal from the third sensor 75. For convenience of explanation, this center position is referred to as the third position. The control unit 46 uses (i) information on the first position and / or information on the second position of the wafer W, and (ii) information on the third position. For example, the control unit 46 calculates the amount of deflection of the wafer W by subtracting the value of the third position from the average value of the first position and the second position. Alternatively, the control unit 46 may calculate the value obtained by subtracting the value of the third position from the value of the first position (or the value of the second position) as the amount of deflection of the wafer W. In this manner, the determination process for the wafer W is completed.

[0085] As described above, with the angle of the FOUP 100 relative to the support frame 43 fixed, the scanner unit 45 can detect the vertical positions of the first portion Wb1, the second portion Wb2, and the third portion Wb3 of the edge surface Wb of each wafer W. Then, the control unit 46 can determine whether each wafer W is properly accommodated in the FOUP 100. Furthermore, the control unit 46 can calculate the amount of deflection of a wafer W properly accommodated in the FOUP 100. Therefore, it is possible to determine whether a wafer W is properly accommodated in the FOUP 100 and calculate the amount of deflection of the wafer W without rotating the FOUP 100.

[0086] Furthermore, the first portion Wb1, which is located relatively close to the support portion 113R, and the second portion Wb2, which is located relatively close to the support portion 113L, hardly sag. The first portion Wb1 and the second portion Wb2 may be considered to be substantially unsag. Therefore, using the first position information and the second position information, it is possible to accurately determine whether each wafer W is located in the correct position within the FOUP 100. Furthermore, because portions located relatively far from the support portions 113R and 113L in the left-right direction are more likely to sag due to their own weight, the third portion Wb3 is more likely to sag than the first portion Wb1 and the second portion Wb2. Therefore, using the third position information and the first position information and / or the second position information, the amount of sag of each wafer W can be accurately calculated.

[0087] Furthermore, each sensor 72 can adjust the angle of the optical axis A of the detection light about the vertical axis by an angle adjustment unit 83. This allows the edge Wb of each wafer W to be reliably detected by adjusting the angle of the optical axis A about the vertical axis, even when wafers W of various shapes and / or sizes are handled on the load port 4.

[0088] Furthermore, a configuration that allows adjustment of the angle of the optical axis A around the vertical axis is even more effective when the end face Wb of the wafer W is not straight in the vertical direction. More specifically, consider a cross section of the wafer W parallel to the vertical direction (see, for example, FIG. 2A ). In this cross section, the end face Wb of the wafer W extends linearly in the vertical direction. For example, if the end face Wb is linear in this cross section, the portion of the end face Wb that is approximately perpendicular to the optical axis A extends long in the vertical direction. Therefore, the laser light reflected by the end face Wb is easily detected by the light receiving unit 82, and the end face Wb can be easily detected by the sensor 72. On the other hand, if the upper and lower ends of the end face Wb are rounded in the cross section, the portion of the end face Wb that is approximately perpendicular to the optical axis A is relatively short in the vertical direction. Therefore, the laser light reflected by the end face Wb may be difficult to detect by the light receiving unit 82. In this regard, in this embodiment, the angle of the optical axis A around the vertical axis is adjustable. Therefore, when viewed from above and below (see, for example, FIG. 9A), the portion of the end face Wb that is approximately perpendicular to the optical axis A can be secured as wide as possible. In other words, even if there is a disadvantage due to the end face Wb not being linear in the cross section, this disadvantage can be compensated for. Therefore, the end face Wb can be reliably detected.

[0089] Furthermore, wafers W generally have a substantially circular cross section. Therefore, the configuration of this embodiment, in which the angle of the optical axis A of each sensor 72 around the vertical axis is adjusted and the optical axis A is arranged substantially perpendicular to the end face Wb, is particularly effective for load ports 4 that handle FOUPs 100 containing wafers W.

[0090] Next, a modified example of the embodiment will be described, with the same reference numerals being used to designate components having the same configuration as the embodiment, and the description thereof will be omitted as appropriate.

[0091] (1) In the above embodiment, the control unit 46 sequentially scans the first sensor 73 (step S101), the second sensor 74 (step S102), and the third sensor 75 (step S103). However, this is not limited to this. The control unit 46 may be configured to simultaneously store information on the detection results of all three sensors 72 in association with vertical position information of the detection unit 61 when the detection unit 61 is initially moved from the upper end position to the lower end position. If the control unit 46 has such a function, the time required to obtain information on the vertical positions of the first portion Wb1, the second portion Wb2, and the third portion Wb3 can be reduced.

[0092] (2) In the above-described embodiment, the three sensors 72 are positioned approximately equal in the vertical direction. However, this is not limited to this. The vertical position of one or more of the first sensor 73, the second sensor 74, and the third sensor 75 may be different from the vertical positions of the other sensors 72. In this case, the control unit 46 may be configured to correct the vertical position information of the three sensors 72. More specifically, the control unit 46 may treat the vertical position information of a specific sensor 72 (e.g., the first sensor 73) as information on the base vertical position of the detection unit 61. In this case, it is preferable that the control unit 46 pre-stores, for example, the following first distance information and second distance information. The first distance information is information on the relative distance between the first sensor 73 and the second sensor 74 in the vertical direction. The second distance information is information on the relative distance between the first sensor 73 and the third sensor 75 in the vertical direction. It is preferable that the control unit 46 corrects the vertical position information of the second sensor 74 using the base position information and the first distance information. The control unit 46 preferably corrects the vertical position information of the third sensor 75 using the basic position information and the second distance information. Such correction can reduce the occurrence of erroneous determinations due to vertical positional deviations of the three sensors 72. The above process is effective when, for example, it is necessary to vary the vertical positions of the three sensors 72 due to design or other reasons. Alternatively, the above correction is also effective when, for example, a design error unintentionally causes a slight deviation in the vertical positions of the three sensors 72.

[0093] (3) In the above-described embodiments, the control unit 46 uses information on the length of the first portion Wb1 in the vertical direction (hereinafter referred to as the first thickness) as information on the thickness of the wafer W. However, this is not limited to this. For example, the control unit 46 may use information on the length of the second portion Wb2 in the vertical direction (hereinafter referred to as the second thickness) as information on the thickness of the wafer W. The control unit 46 may use both the information on the first thickness and the information on the second thickness as information on the thickness of the wafer W. When both pieces of information are used as information on the thickness of the wafer W, the control unit 46 may, for example, compare the average value of the first thickness and the second thickness with a reference thickness.

[0094] (4) In the above-described embodiments, the detection unit 61 has three sensors 72. However, this is not limited to this. The detection unit 61 may have four or more sensors 72. This may provide more detailed information about the deflection of the wafer W. Alternatively, the detection unit 61 may have only one or two sensors 72. In this case, the scanner unit 45 needs to have a left-right movement mechanism (not shown) that drives the detection unit 61 to move in the left-right direction.

[0095] (5) The container placed on the load port 4 is not limited to the FOUP 100. For example, a publicly known open cassette (not shown) may be placed on the load port 4. The diameter of the wafer W contained in the open cassette is, for example, approximately 200 mm. When multiple types of containers are placed on the load port 4 in this manner, it may be necessary to change the angle of the optical axis A of each sensor 72 around the vertical axis. In this case, the angle adjustment unit 83 described above is particularly effective. Furthermore, the substrate contained in the container may include something other than the wafer W. The substrate may include, for example, a frame (not shown) to which the wafer W is fixed. Even if such a frame bends slightly, the amount of bending of the substrate can be detected. Alternatively, a substrate other than the wafer W and the frame (e.g., a glass substrate) may be placed in the container. The shape of the substrate may be a shape other than a substantially circular plate. For example, the substrate may be substantially rectangular when viewed from above.

[0096] (6) In the above-described embodiment, each sensor 72 is configured so that the angle of the optical axis A about the vertical axis can be adjusted by the angle adjustment unit 83. However, this is not limited to this. For example, the angle of the optical axis A about the vertical axis may be adjustable only in the first sensor 73 and / or the second sensor 74. Alternatively, the angle of the optical axis A about the vertical axis of each sensor 72 may be fixed.

[0097] (7) In the above-described embodiment, the angle of the optical axis A of each sensor 72 around the vertical axis is set to be approximately perpendicular to the edge Wb of the wafer W in the FOUP 100. However, this is not limited to this. That is, the optical axis A may be tilted from the normal (not shown) to the edge Wb, provided that each sensor 72 is capable of detecting the edge Wb.

[0098] (8) In the above-described embodiment, each sensor 72 is a laser sensor that uses laser light as detection light. However, this is not limited to this. One or more of the multiple sensors 72 may be a known photoelectric sensor that uses light other than laser light as detection light.

[0099] (9) A sensor other than a laser sensor or a photoelectric sensor may be applied to one or more of the sensors 72. For example, a known reflective ultrasonic sensor that can emit and sense ultrasonic waves as a detection medium may be applied to the sensor 72.

[0100] (10) The detection unit 61 may have, for example, three or more cameras (not shown) instead of the three or more sensors 72. The detection unit 61 may have any device as long as it is configured to be able to detect three or more portions of the edge surface Wb of the wafer W that are spaced apart from each other in the left-right direction.

[0101] (11) In the above-described embodiment, the detection unit 61 is driven to move up and down integrally with the door support unit 53 by the motor 58. However, this is not limited to this. The detection unit 61 may be driven to move up and down by a drive source (not shown) separate from the motor 58.

[0102] (12) In the above-described embodiments, the load port 4 has a control unit 46. However, this is not limited to this. For example, the control device 5 of the EFEM 1 may control the load port 4. In this case, the control device 5 corresponds to the determination unit of the present invention.

[0103] (13) The load port 4 may be mounted on equipment other than the EFEM 1.

[0104] (14) In the above-described embodiments, the scanner unit 45 including the detector 61 is provided on the load port 4. However, this is not limited to this. For example, in the EFEM 1, the transport robot 3 may have the detector 61 instead of the load port 4. The transport robot 3 may support the detector 61 and drive it to move up and down and back and forth. In this case, the EFEM 1 is a mapping device having a mapping function. In addition, in this case, the transport robot 3 corresponds to the scanner unit of the present invention. The control device 5 may function as the determination unit of the present invention and perform the mapping process. As described above, the load port 4 may be mounted on equipment other than the EFEM 1. In other words, a mapping device (not shown) separate from the EFEM 1 may include a load port (not shown) that does not have the scanner unit 45, a scanner unit (not shown) provided separately from the load port, and a determination unit (not shown). The mapping device may include components corresponding to the base unit and placement unit of the present invention instead of the load port.

[0105] 4 Load port 43 Support frame (base) 44 Placement section 45 Scanner section 46 Control section (determination section) 58 Motor (drive section) 71 Main body (support section) 73 First sensor 74 Second sensor 75 Third sensor 81 Light emitter 82 Light receiver 100 FOUP (container) 113L Support section (second support section) 113R Support section (first support section) A Optical axis W Wafer (substrate) Wb End face Wb1 First section Wb2 Second section Wb3 Third section

Claims

1. A load port comprising: a base portion having a fixed installation position; a placement portion attached to the base portion on which a container containing a plurality of substrates arranged vertically is placed; a scanner portion configured to detect the plurality of substrates contained in the container; and a judgment portion configured to make a judgment regarding the state of each of the plurality of substrates detected by the scanner portion, wherein the scanner portion is configured to detect a predetermined first portion, a second portion and a third portion of the end face of each of the plurality of substrates, the first portion and the second portion being spaced apart from each other in the extension direction of the end face of each of the plurality of substrates, while the container is placed on the placement portion and a fixed state is maintained in which an angle of the container about a vertical axis relative to the base portion is fixed; and the judgment portion judges whether each substrate is normally contained in the container by using information on a first position, which is the position of the first portion in the vertical direction, and information on a second position, which is the position of the second portion in the vertical direction, and A load port characterized by calculating an amount of vertical deflection of a substrate among the plurality of substrates that is normally contained in the container by using information on the first position, information on the second position, or both of the first position, and information on a third position, which is the vertical position of the third portion.

2. The load port described in claim 1, characterized in that the scanner unit has: a first sensor configured to be able to detect the first portion; a second sensor separate from the first sensor configured to be able to detect the second portion; a third sensor separate from the first sensor and the second sensor configured to be able to detect the third portion; a support unit that supports the first sensor, the second sensor, and the third sensor; and a drive unit configured to be able to drive the support unit to move in a vertical direction.

3. A load port as described in claim 1 or 2, characterized in that when the container is in the fixed state, a first support part for supporting each of the plurality of substrates within the container is arranged on one side of the center of the container in a predetermined container width direction perpendicular to the vertical direction, and a second support part for supporting each of the plurality of substrates within the container is arranged on the other side of the center of the container in the container width direction, the first part is arranged on the first support part side of the center of the container in the container width direction, the second part is arranged on the second support part side of the center of the container in the container width direction, and the third part is arranged between the first part and the second part in the container width direction.

4. A load port as described in claim 1 or 2, characterized in that the scanner unit has a reflective optical sensor including a light-emitting unit configured to emit detection light for detecting the end face and a light-receiving unit configured to sense the detection light reflected by the end face, and an angle adjustment unit configured to adjust the angle of the optical axis of the detection light emitted from the light-emitting unit about the vertical axis.

5. The load port according to claim 4, characterized in that the plurality of substrates include a plurality of wafers which are semiconductor substrates, and the reflective optical sensor is positioned so that the optical axis is perpendicular to the end face of each of the plurality of substrates.

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