Load port

Abstract

To calculate a deflection amount of a substrate in a container without rotating a container.SOLUTION: A load port 4 comprises: a support frame 43; a mounting part 44 to which a FOUP 100 in which a plurality of wafers W is housed is mounted; a scanner part 45; and a control part 46. In the scanner part 45, the FOUP 100 is mounted onto the mounting part 44, and a first part Wb1, a second part Wb2, and a third part Wb3 of an end surface Wb of the wafer W are detected while maintaining a fixing state where an angle of a vertical shaft circumference to the support frame 43 of the FOUP 100 is fixed. The control part 46 uses information on a first position of the first part Wb1 and information on a second position of the second part Wb2, and determines whether or not each wafer W is normally housed in the FOUP 100. The control part 46 uses the information on the first position or the information on the second position or both of the information, and information on a third position of the third part Wb3 to calculate a deviation amount in a vertical direction of the wafer W normally housed in the FOUP 100.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] A load port on which a container that contains a plurality of wafers (hereinafter, substrates) arranged vertically is placed has been conventionally known. Many of the load ports in recent years have a mapping function for detecting the state of each substrate in the container. For example, the portion corresponding to the load port in the substrate loading / unloading device disclosed in Patent Document 1 has a placement section on which a cassette (hereinafter, container) is placed, a substrate detector, and a drive section (called a shutter drive mechanism in Patent Document 1). The substrate detector has a transmission type optical sensor including a light irradiating means and a light detecting means, and is driven to move in the vertical direction by the drive section. The light irradiating means and the light detecting means are arranged on opposite sides to each other in the horizontal direction, separated by an end of the substrate in the container near the substrate detector. When the light irradiated from the light irradiating means is blocked in a certain area in the vertical direction during the vertical movement of the substrate detector, it is determined that the substrate is present in the area.

[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 be able to measure the amount of deflection of each substrate due to its own weight. More specifically, the pitch measurement device has 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 substrate 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 a scanning operation of moving the photoelectric element from a predetermined upper end position to a predetermined lower end position multiple times. The rotating base changes the rotation angle of the container at the timing between one scanning operation and the next scanning operation. This detects the height positions of multiple positions of each substrate in the circumferential direction of the rotating base. The amount of deflection is measured by calculating the difference between the height position of the highest point and the height position of the lowest point for each substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-7182 A [Patent Document 2] Publication No. 3177757 Summary of the Invention [Problem to be solved by the invention]

[0005] With the recent trend of further thinning of substrates, the inventors of the present application are considering measuring the deflection amount of a substrate in a load port as well. One of the purposes is to utilize information on the deflection amount in the operation control of a substrate transport device that transports a substrate in a container placed on a load port. However, in the substrate detector described in Patent Document 1, the light irradiated from the light irradiating means moving up and down is blocked for a similarly long time in both cases where the substrate is simply deflected or where the substrate is stored in the container in an abnormal tilted state. For this reason, the substrate detector cannot distinguish whether the substrate normally stored in the container is simply deflected or whether the substrate is stored in the container in an abnormal state. Therefore, it is considered to detect the end face of the substrate using the photoelectric element described in Patent Document 2. However, in the load port described in Patent Document 1, the container cannot be rotated between one scanning operation and the next scanning operation. For this reason, the invention described in Patent Document 2 cannot be directly applied to the load port.

[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. [Means for solving the problem]

[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 judgment portion configured to make a judgment regarding a state of each of the plurality of substrates detected by the scanner portion, wherein the scanner portion detects the angle of the container about a vertical axis relative to the base portion in an extension direction of each of the end faces of the plurality of substrates while the container is placed on the placement portion and a fixed state is maintained in which the angle of the container about a vertical axis relative to the base portion is fixed. 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 position of the first part in the vertical direction, and information on a second position, which is the position of the second part in the vertical direction, to judge whether each substrate is normally contained in the container, and calculates the amount of vertical deflection of a substrate among the plurality of substrates that is normally 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 position of the third part in the vertical direction.

[0008] In the present invention, the scanner unit can detect the vertical positions of the first, second and third parts of the end face of each substrate in a fixed state with the angle of the container relative to the base unit.Then, the determination unit can 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 a substrate is properly accommodated in the container and to calculate the amount of deflection of the substrate without rotating the container.

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

[0010] In the present invention, the first sensor, the second sensor, and the third sensor can be moved vertically at the same time. This allows the first position information, the second position information, and the third position information to be obtained at the same time 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 part for supporting each of the multiple 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 multiple 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.

[0012] In the present invention, the first portion arranged relatively close to the first support and the second portion arranged relatively close to the second support hardly bend. Therefore, by using the information on the first position and the information on the second position, it is possible to accurately determine whether each substrate is arranged in a correct position in the container. Furthermore, since the portion arranged relatively far from the first support and the second support in the container width direction is likely to bend under its own weight, the third portion is likely to sag more than the first and second portions. Therefore, by using the information on the third position and the information on the first position and / or the information on the second position, the amount of bending of each substrate can be accurately calculated.

[0013] The load port of the fourth invention is characterized in that, in the first or second invention, the scanner unit has a reflective optical sensor including an optical emitter configured to emit detection light for detecting the end face and a optical receiver 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 optical emitter about a vertical axis.

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

[0015] The load port of the fifth invention is characterized in that, in the fourth invention, 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 disposed substantially perpendicular to the end face is particularly effective in a load port that handles containers that house substrates including wafers. [Brief description of the drawings]

[0017] [Figure 1]FIG. 1 is a schematic plan view of an EFEM equipped with a load port according to the present embodiment and its surroundings. [Diagram 2] 1A is a side cross-sectional view of the FOUP, and FIG. 1B is a rear view of the FOUP with the lid removed. [Diagram 3] 13(a) and 13(b) are diagrams showing wafers stored in an abnormal state in a FOUP. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] 5(a) and 5(b) are diagrams illustrating the operation of a load port. [Figure 8] 5(a) and 5(b) are diagrams illustrating the operation of a load port. [Figure 9] FIG. 2A is a diagram showing the arrangement of the scanner units, and FIG. 2B is a diagram showing portions of the edge surface of the wafer that are detected by each of a plurality of sensors. [Figure 10] 1 is a flowchart showing the entire mapping process; [Figure 11] 13 is a flowchart showing a judgment process for each wafer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] An embodiment of the present invention will be described. For ease of explanation, the directions shown in FIG. 1 are defined as the front-rear and left-right directions. More specifically, the direction in which the EFEM 1 (described later) and the 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 parallel to the vertical direction in which gravity acts.

[0019] (Overview of the load port and its surroundings) The schematic configuration of the load port 4 and its periphery according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic diagram of an EFEM 1 equipped with a plurality of load ports 4 and its periphery. "EFEM" is an abbreviation of "Equipment Front End Module". The EFEM 1 is a device for transporting a wafer W between a FOUP 100 (described later) placed on each load port 4 and a processing device 6. The wafer W is, for example, a substantially disk-shaped semiconductor substrate. The diameter of the wafer W accommodated in the FOUP 100 is, for example, about 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 disposed 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. Behind the EFEM 1, a processing device 6 is disposed.

[0021] The EFEM 1 is installed at a predetermined position in, for example, a semiconductor factory. The EFEM 1 transfers the wafer W between the processing device 6 and a FOUP 100 placed on a load port 4 by a transfer robot 3 arranged in a transfer space 9 in a housing 2. "FOUP" is an abbreviation for "Front-Opening Unified Pod." The FOUP 100 is a container capable of accommodating 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 wafer W is 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 wafer 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 detachably attach a lid 102 (described later) to a FOUP body 101 (described later) 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 later.

[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 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 (sputtering, dry etching, etc.), or may be another process. As shown in FIG. 1, the processing apparatus 6 has, for example, a load lock chamber 7 and a processing chamber 8. The load lock chamber 7 is a room for temporarily waiting the wafer W. The load lock chamber 7 is disposed between the transfer space 9 and the processing chamber 8. The processing chamber 8 is a room for performing a predetermined process on the wafer W.

[0026] (FOUP) An example of the configuration of the 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-rear, left-right, top-bottom 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 FIG. 2(a) and FIG. 2(b), the FOUP 100 has a FOUP body 101 and a lid 102. The FOUP body 101 is a member having a generally rectangular parallelepiped shape. 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 having a generally rectangular shape when viewed from the rear.

[0028] The plurality of support parts 113 are for supporting the plurality of wafers W substantially horizontally. Each of the plurality of support parts 113 is, for example, a substantially flat plate-shaped member. Each of the support parts 113 extends long in the front-rear direction. The thickness direction of each of the support parts 113 is substantially parallel to the up-down direction. Each end of the wafer W in the left-right direction is placed on the upper surface of one of the support parts 113. As shown in FIG. 2(b), the plurality of support parts 113 are arranged in a substantially rectangular parallelepiped space surrounded by the FOUP body 101. Each of the plurality of support parts 113 is fixed, for example, to an inner surface of one of both ends in the left-right direction of the outer wall part 111. For convenience of explanation, the plurality of support parts 113 fixed to the inner surface of the left end part of the outer wall part 111 among the plurality of support parts 113 will be referred to as a plurality of support parts 113L hereinafter. The plurality of support parts 113L are arranged to the left of the center in the left-right direction of the FOUP 100. The multiple support parts 113L are arranged side by side in the vertical direction. Each of the multiple support parts 113L corresponds to a second support part of the present invention. Of the multiple support parts 113, the multiple support parts 113 fixed to the inner surface of the right end part of the outer wall part 111 will be referred to as multiple support parts 113R below for convenience of explanation. The multiple support parts 113R are arranged to the right of the center in the left-right direction of the FOUP 100. The multiple support parts 113R are arranged side by side in the vertical direction. Each of the multiple support parts 113R corresponds to a first support part of the present invention.

[0029] The number of the multiple support parts 113L is the same as the number of the multiple support parts 113R. That is, the multiple support parts 113L and the multiple support parts 113R correspond one-to-one. One support part 113L and one support part 113R corresponding to each other are arranged at approximately the same position in the vertical direction. Such a pair of support part 113L and support part 113R are 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 aid in the following explanation, the state of the wafers W accommodated in the FOUP 100 will be briefly explained 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. Figs. 3(a) and 3(b) show only one or more wafers W accommodated in one of the multiple slots.

[0032] When each wafer W is accommodated in the FOUP 100 in a normal state, as shown in FIG. 2(b), the multiple wafers W are placed on the multiple pairs of 113L and 113R. Such a state of the wafer W is called a single state. On the other hand, the wafer W may be accommodated in the FOUP 100 in an abnormal state. For example, as shown in FIG. 3(a), the wafer W may be placed on a certain support 113L and a support 113R that is arranged at a position shifted in the vertical direction from the support 113L. Such a state of the wafer W is called a cross state. Alternatively, for example, as shown in FIG. 3(b), two wafers W may be accommodated in the same slot in a state where they are overlapped in the vertical direction. Such a state of the 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] (Loading 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 FIGS. 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 plate-shaped member. The base 41 has a substantially rectangular shape when viewed from the front-rear direction. The base 41 is arranged to extend in the up-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 an upper portion of the base 41. The opening 41a has a size that allows the lid 102 of the FOUP 100 to pass through in the front-rear direction. The opening 41a is opened and closed by a door main body 50 described below.

[0037] The door mechanism 42 is configured so that the lid 102 can be attached to and detached from the FOUP body 101. As shown in Figures 4 and 5, the door mechanism 42 has, 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-like member. When viewed from the front and rear directions, 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 for suctioning and holding 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 by 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 and 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 fixing device (not shown). The door support portion 53 extends in the up-down 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 is moved in the front-rear direction to move the door body 50 between a closed position (see FIG. 7(b)) and an open position (see FIG. 8(a)). The closed position is a 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 behind the closed position, and is a 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-down direction. The lifting block 55 movably supports the door support part 53 by a guide rail 54. The lifting block 55 is guided in the up-down direction along the guide rail 56. The lifting block 55 is driven to move in the up-down direction by a motor 58. The lifting block 55 is moved in the up-down direction to move the door main body 50 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-down direction. The guide rail 56 is attached to, for example, the base 41. The guide rail 56 extends in the up-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 lift 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.) 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 middle portion 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-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 between a predetermined delivery position and a cover opening / closing position rearward of the delivery position by a driving mechanism (not shown). The delivery position is a position of the placement unit 44 when the FOUP 100 is in a state where it can be delivered to and from a FOUP conveying device (not shown). The placement unit 44 may be further 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 has a detection unit 61, a support member 62, and a front-rear drive unit 63.

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

[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 member that is generally C-shaped 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 that extends downward from the left end of the upper end 62a, and a lower end 62c that extends 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 to this, 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 supported to be swingable by, for example, the door support portion 53. The swing axis direction of the support member 62 may be, for example, approximately parallel to the left-right direction. The support member 62 may be swingably driven by, for example, the front-rear drive portion 63.

[0047] The front-rear drive unit 63 is for driving 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, a ROM, and a 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 of 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 clamp mechanism (not shown) that presses the FOUP body 101 against the base 41. Details of these will be omitted.

[0050] (Basic operation of the 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 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 pin 44a and fixed to the placement unit 44 by the lock claw 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)). As a result, each of the multiple latch keys 52 (see FIG. 4) approaches the FOUP 100 relatively and is inserted into each of the multiple keyholes formed in the lid 102. When the placement unit 44 is located at the lid opening / closing position, it does not move or rotate. That is, the angle of the FOUP 100 around the vertical axis relative to the support frame 43 is maintained in a fixed state. For convenience of explanation, such a state of the FOUP 100 is called a fixed state. When the FOUP 100 is in the fixed state, the width direction of the opening 112a (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, and 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 purging process for replacing 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 adsorb 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. 7(b)) to the scan position (see FIG. 8(a)). 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 multiple wafers W arranged vertically in order from above. The control unit 46 performs a mapping process based on the position information of the multiple wafers W detected by the detection unit 61. In this embodiment, the mapping process is a process that includes a determination of whether the multiple wafers W are normally 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 to 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 further moves it 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 opening / closing position to the delivery position. In this manner, a series of processes from when the FOUP 100 is transported to the load port 4 until it is ready for removal is completed.

[0058] (Wafer deflection) Here, in recent years, the wafer W has been further thinned. The thickness of a conventional wafer W is, for example, 0.775 mm. In recent years, the thickness of the wafer W has tended to be very thin, such as 0.1 mm to 0.2 mm. Accordingly, bending of the wafer W mainly due to its own weight has become evident. The bending 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 bend. In either pattern, it is understood that the portion of the wafer W that is not supported by the support portion 113 is bent due to its own weight.

[0059] From the above circumstances, it is required to calculate the amount of deflection of the wafer W during the mapping process in the load port 4. For example, JIS-3177757 discloses an apparatus for calculating the amount of deflection of a substrate (not shown) in a container (not shown). However, in this apparatus, the angular position of the container about the vertical axis needs to be changed during the mapping process. In the load port 4, when the placement unit 44 is located at the cover opening / closing position (FIG. 7(b)), even if the placement unit 44 is rotated during the mapping process, the FOUP 100 interferes with the base 41. Therefore, in this embodiment, in order to measure the amount of deflection of the wafer W in the FOUP 100 without rotating the FOUP 100, the load port 4 has the following configuration. More specifically, the scanner unit 45 has the following configuration.

[0060] (Details of the scanner section) The detailed configuration of the scanner unit 45 will be described with reference to Figures 9(a) and 9(b). Figure 9(a) is a plan view that shows a schematic arrangement of the scanner unit 45. Figure 9(b) is a view showing a portion of the edge Wb of the wafer W that is detected by each of a plurality of sensors 72, which will be described later. The direction shown in Figure 9(b) is the same as the direction shown in Figure 2(b). Please note that the left-right direction in this embodiment is opposite to the left-right direction on the paper in Figures 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. 9(a), 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 the 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 roughly parallel to the left-right direction. The main body 71 supports the three sensors 72. The main body 71 corresponds to the support section 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 device 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 composed of the same member.

[0063] As shown in FIG. 9(a), 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 on the rear side of the FOUP 100 on the placement portion 44. In the left-right direction, the center position of the long portion 71a is substantially equal to the center position of the placement portion 44 (i.e., the center position of the FOUP 100 on the placement 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 portion 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, for example, from the left end portion of the long portion 71a.

[0064] Each of the three sensors 72 is configured to be able to detect the end face 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 light for detecting the end face Wb. The reflective laser sensor corresponds to the reflective optical sensor of the present invention. It is preferable that the three sensors 72 are disposed at approximately equal positions in the vertical direction.

[0065] Each sensor 72 has a light emitting unit 81 and a light receiving unit 82. The light emitting unit 81 has a light emitting element (not shown) capable of emitting laser light (see the two-dot chain line arrow in FIG. 9(a)). The light emitting unit 81 is arranged 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 arranged substantially horizontal. Also, the optical axis A of the light emitting unit 81 is arranged to be substantially perpendicular to a part 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 shape of the beam may be a shape other than substantially circular, such as an ellipse or a substantially rectangular shape. It is preferable that the length of the beam in the vertical direction is smaller than, for example, the thickness of the wafer W (i.e., the design length in the vertical direction of the end face Wb). The light receiving unit 82 has a light receiving element (not shown) capable of sensing the laser light (see the two-dot chain line arrow in FIG. 9(a)). 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 has a plurality of angle adjustment units 83. The plurality of angle adjustment units 83 are configured to independently adjust the angles of the optical axes A of the plurality of sensors 72 about the vertical axis. Each angle adjustment unit 83 may have, for example, a screw (not shown) for fixing the sensor 72 to the main body 71. The angle of the sensor 72 about 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 have, for example, a rotating shaft (not shown), a gear (not shown), and a knob (not shown). The rotating shaft may support the sensor 72 so as to be rotatable about the vertical axis. The gear may be provided coaxially with the rotating shaft and fixed to the rotating shaft. The knob may have a member that meshes with the gear. The knob may be configured to be able to be turned by an operator. The knob may be configured to rotate the sensor 72 gradually about the vertical axis via the gear. Alternatively, the angle adjustment unit 83 may have a motor (not shown) including a rotating shaft instead of a knob. 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 of the three sensors 72 will be described. Assume that the placement section 44 on which the FOUP is placed is located in the cover opening / closing position (see FIG. 7(b)). As shown by the dashed line in FIG. 9(b), an imaginary line extending in the vertical direction passing through the center in the left-right direction of the FOUP 100 when viewed from the front-rear direction is defined as an imaginary center line LC. As shown by the dashed line in FIG. 9(b), an imaginary line extending in the vertical direction passing through the left ends of the multiple support parts 113R is defined as a first right line L1R. An imaginary line extending in the vertical direction passing through the right ends of the multiple support parts 113L is defined as a first left line L1L. An imaginary line extending in the vertical direction passing through a position exactly midway between the imaginary center line LC and the first right line L1R in the left-right direction is defined as a second right line L2R. An imaginary line extending in the vertical direction passing through a position exactly midway between the imaginary center line LC and the first left line L1L in the left-right direction is defined as a second left line L2L.

[0068] As shown in Fig. 9(a), the three sensors 72 include a first sensor 73, a second sensor 74, and a third sensor 75. The first sensor 73 is attached, for example, to the front end of the protrusion 71b. The optical axis A1 of the first sensor 73 is disposed so as to be approximately perpendicular to a first portion Wb1 (see Figs. 9(a) and 9(b)) which is a part of the end surface 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 later.

[0069] The second sensor 74 is attached to, for example, the front end of the protruding portion 71c. The optical axis A2, which is the optical axis A of the second sensor 74, is disposed so as to be approximately perpendicular to the second portion Wb2 (see FIGS. 9(a) and 9(b)). The second portion Wb2 is a part of the end face Wb of the wafer W, and is a part different from the first portion Wb1. The second portion Wb2 is located rearward of the center in the front-rear direction of the wafer W. 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 later.

[0070] The third sensor 75 is attached, for example, to the center of the long 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 protruding portion 71b and the protruding portion 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. 9(a) and 9(b)). The third portion Wb3 is a part of the end surface Wb of the wafer W, and is a part different 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 later.

[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. 9(b), the first portion Wb1 is located to the right of the virtual center line LC. It is preferable that the first portion Wb1 is located to the left of the first right straight line L1R (in other words, on the inside in the left-right direction). It is more preferable that the first portion Wb1 is located between the first right straight line L1R and the second right straight line L2R in the left-right direction. That is, 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 end surface Wb of the wafer W that is less likely to bend. The second portion Wb2 is located to the left of the virtual center line LC. More specifically, it is preferable that the second portion Wb2 is located to the right of the first left straight line L1L (in other words, on the inside in the left-right direction). It is more preferable that the second portion Wb2 is 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 113L in the left-right direction. Therefore, the second portion Wb2 is a portion of the end surface Wb of the wafer W that is less likely to bend, similar to the first portion Wb1. 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 is disposed, for example, on the virtual center line LC. That is, the third portion Wb3 is disposed at a position far from both the support 113R and the support 113L in the left-right direction. Therefore, the third portion Wb3 is a portion of the end 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 Fig. 10 and Fig. 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 multiple wafers W is placed on the placement portion 44. The placement portion 44 is located in the lid opening / closing 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 portion 61 is located in the scan position (see FIG. 8(a)).

[0074] First, the control unit 46 executes a scan of 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 unit 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. It is preferable that the length of each step in the vertical direction (step length) when the detection unit 61 moves is shorter than the length of the optical axis A of each sensor 72 in the vertical direction, for example. The control unit 46 calculates the position information of the detection unit 61 in the vertical direction by using the information of the step length and the information of the number of pulse signals sent to the motor 58. When the first sensor 73 detects the detection light, it sends a detection signal indicating that the first portion Wb1 has been detected to the control unit 46. The control unit 46 stores the position information of the detection unit 61 in the vertical direction and the information of the detection signal from the first sensor 73 in association with each other.

[0075] After completing the scan of the first sensor 73, the control unit 46 executes a scan of 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 moves the detection unit 61 to the lower end position again. When the second sensor 74 detects 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 the position information of the detection unit 61 in the up-down direction with the information of the detection signal from the second sensor 74 and stores them. Alternatively, when returning the detection unit 61 from the lower end position to the upper end position, the control unit 46 may associate the position information of the detection unit 61 in the up-down direction with the information of the detection signal from the second sensor 74 and store them.

[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 in the same manner 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 stores the position information of the detection unit 61 in the up-down direction and the information of the detection signal from the third sensor 75 in association with each other.

[0077] Next, the control unit 46 sequentially performs a judgment process (details will be described later) including a process of calculating the amount of deflection for each wafer W. More specifically, the control unit 46 inputs, for example, 1 into a predetermined variable N (step S104) and performs a judgment process for the wafer W accommodated in the first slot (step S105). The control unit 46 judges whether the judgment process for all wafers W has been completed (step S106). If there is a wafer W for which the judgment 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 judgment process for the wafer W next to the wafer W for which the judgment has been completed immediately before (i.e., the wafer W related to the Nth slot) (step S105). After the judgment process for all wafers W has been completed (step S106: Yes), the control unit 46 ends the mapping process.

[0078] While the mapping process is being performed, the placement 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] (Decision making process) The judgment process for each wafer W will be described with reference to Fig. 11. In summary, the control unit 46 judges whether the wafer W to be judged (the wafer W associated with the Nth slot described above) is normally accommodated in the FOUP 100, and then calculates the amount of deflection of the wafer W.

[0080] First, the control unit 46 judges whether or not the wafer W to be judged 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, the central position is called 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, the central position is called the second position. The control unit 46 judges, for example, whether at least one of the first position and the second position of the wafer W is within a predetermined set range. The predetermined set range is a range of positions in the vertical direction corresponding to the wafer W to be judged. For example, the upper limit value and the lower limit value of the 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 limit value and the lower limit value may be stored in advance in the control unit 46 or another computer device by, for example, a predetermined teaching. When at least one of the first position and the second position of the wafer W falls within the set range, the control unit 46 determines that the wafer W to be judged is present (step S201: Yes) and proceeds to the next step. On the other hand, when the wafer W is not accommodated in the Nth slot, neither the first part Wb1 nor the second part Wb2 is detected within the set range. When neither the first position nor the second position is included 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 judges that "substrate is not present" (step S202). When the judgment of "substrate is not present" is made, the control unit 46 ends the judgment 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 judges whether the wafer W to be judged is in a cross state. The control unit 46 judges whether the difference value (absolute value) between the first position and the second position of the wafer W is larger than a predetermined reference value (step S203). The reference value is a threshold value for judging whether the wafer W is accommodated in the FOUP 100 in an inclined state. The reference value is input in advance to the control unit 46 or another computer device when the load port 4 is set up. Alternatively, the reference value may be stored in advance in the control unit 46 or another computer device by, for example, predetermined teaching. The reference value may be, for example, half the value of the pitch in the vertical direction of the multiple slots of the FOUP 100. If the difference value is larger than the reference value (step S203: Yes), the control unit 46 performs a cross judgment to judge that the state of the wafer W is in a cross state (step S204). If the cross judgment is performed, the control unit 46 ends the judgment process for the wafer W.

[0083] When the difference value is equal to or smaller than the reference value (step S203: No), the control unit 46 then judges whether the wafer W is in a double state. More specifically, the control unit 46 acquires information on the length of the wafer W in the vertical direction (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 any one or more sensors 72. The control unit 46 may use, for example, information on the length of the first portion Wb1 in the vertical direction as information on the thickness of the wafer W. The control unit 46 judges whether the thickness of the wafer W is larger than a predetermined reference thickness using the information (step S205). The reference thickness is a threshold value for judging whether two or more wafers W are accommodated in the same slot of the FOUP 100. The value of the reference thickness is also stored in advance in the control unit 46 or another computer device, like the above reference value. The value of the reference thickness may be, for example, 1.5 times the specification value of the thickness of the wafer W. Note that the value of the reference thickness is not limited to this. If the thickness of the wafer 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] When the thickness of the wafer W is equal to or smaller than the reference thickness (step S205: No), the control unit 46 performs a single determination (step S207). The single determination is a determination indicating that the wafer W is in a single state in which the wafer W is normally accommodated in the FOUP 100. Furthermore, the control unit 46 calculates the amount of deflection of the wafer W (step S207). More specifically, the control unit 46 calculates the center position of the third portion Wb3 of the wafer W in the vertical direction based on the position information in the vertical direction of the detection unit 61 and the detection signal from the third sensor 75. For convenience of explanation, the center position is called the third position. The control unit 46 uses (i) the information on the first position and / or the information on the second position of the wafer W, and (ii) the information on the third position. For example, the control unit 46 calculates the value obtained by subtracting the value of the third position from the average value of the value of the first position and the value of the second position as the amount of deflection of the wafer W. 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, in a fixed state in which the angle of the FOUP 100 relative to the support frame 43 is 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 end face 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 the wafer W properly accommodated in the FOUP 100. Therefore, it is possible to determine whether the 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] Moreover, the first portion Wb1 arranged at a position relatively close to the support portion 113R and the second portion Wb2 arranged at a position relatively close to the support portion 113L are hardly warped. The first portion Wb1 and the second portion Wb2 may be considered to be substantially not warped. Therefore, by using the information on the first position and the information on the second position, it is possible to accurately determine whether each wafer W is arranged at a normal position in the FOUP 100. Furthermore, since the portion arranged at a position relatively far from the support portion 113R and the support portion 113L in the left-right direction is likely to warp due to its own weight, the third portion Wb3 is likely to sag more than the first portion Wb1 and the second portion Wb2. Therefore, by using the information on the third position and the information on the first position and / or the information on the second position, the amount of warping 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 the angle adjustment unit 83. As a result, even when wafers W of various shapes and / or sizes are handled on the load port 4, the end face Wb of each wafer W can be reliably detected by adjusting the angle of the optical axis A about the vertical axis.

[0088] Moreover, the configuration capable of adjusting 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, a cross section of the wafer W parallel to the vertical direction (see, for example, FIG. 2(a)) is assumed. In the cross section, the end face Wb of the wafer W extends linearly in the vertical direction. In the cross section, for example, when the end face Wb is linear, a portion of the end face Wb that is approximately perpendicular to the optical axis A extends long in the vertical direction. For this reason, 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, in the cross section, when the upper end and the lower end of the end face Wb are rounded, for example, the portion of the end face Wb that is approximately perpendicular to the optical axis A is relatively short in the vertical direction. For this reason, there is a risk that the laser light reflected by the end face Wb is difficult to detect by the light receiving unit 82. In this respect, in this embodiment, the angle of the optical axis A around the vertical axis can be adjusted. For this reason, when viewed from above and below (see, for example, FIG. 9(a)), 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 above cross section, this disadvantage can be compensated for. Therefore, the end face Wb can be reliably detected.

[0089] Moreover, the wafer W generally has 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 disposed substantially perpendicular to the end face Wb is particularly effective for the load port 4 that handles the FOUP 100 containing the wafer W.

[0090] Next, a modified example of the embodiment will be described, in which the same reference numerals will be used to designate components similar to those in 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 the above. The control unit 46 may be configured to simultaneously store information on the detection results of all three sensors 72 in association with position information of the detection unit 61 in the up-down direction 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, it is possible to reduce the time required to obtain information on the positions of the first portion Wb1, the second portion Wb2, and the third portion Wb3 in the up-down direction.

[0092] (2) In the above embodiment, the three sensors 72 are substantially equal in position 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 position of the other sensors 72. In this case, the control unit 46 may be configured to be able 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 the basic position information of the detection unit 61 in the vertical direction. In this case, it is preferable that the control unit 46 stores, for example, the following first distance information and second distance information in advance. 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 by using the basic position information and the first distance information. It is preferable that the control unit 46 corrects the vertical position information of the third sensor 75 using the basic position information and the second distance information. Such a correction can suppress the occurrence of erroneous determination caused by vertical positional deviation of the three sensors 72. The above process is effective when it is necessary to vary the vertical arrangement positions of the three sensors 72 due to design or other reasons. Alternatively, the above correction is also effective when the vertical arrangement positions of the three sensors 72 unintentionally deviate slightly due to design errors.

[0093] (3) In the above embodiments, the control unit 46 uses information on the length of the first portion Wb1 in the up-down direction (hereinafter, 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 up-down direction (hereinafter, 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 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 accommodated in the open cassette is, for example, about 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 about the vertical axis. In this case, the angle adjustment unit 83 described above is particularly effective. In addition, the substrate accommodated 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 is slightly deflected, the amount of deflection of the substrate can be detected. Alternatively, a substrate other than the wafer W and the frame (for example, a glass substrate, etc.) may be accommodated in the container. The shape of the substrate may be a shape other than a substantially circular plate shape. For example, the substrate may be substantially rectangular when viewed from the top and bottom.

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

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

[0098] (8) In the above 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 multiple sensors 72. For example, a known reflective ultrasonic sensor capable of emitting and detecting ultrasonic waves as a detection medium may be applied to the sensor 72.

[0100] (10) Detection unit 61 may have, for example, three or more cameras (not shown) instead of three or more sensors 72. Detection unit 61 may have any device as long as it is configured to be able to detect three or more portions of edge surface Wb of 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 vertically 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 vertically by a drive source (not shown) other than the motor 58.

[0102] (12) In the above 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 embodiment, the scanner unit 45 including the detector 61 is provided on the load port 4. However, this is not limited to the above. 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 be configured to support the detector 61 and move the detector 61 in the vertical and front-rear directions. 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. Also, 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. [Explanation of symbols]

[0105] 4. Loading port 43 Support frame (base) 44 Placement section 45 Scanner section 46 Control section (judgment section) 58 Motor (drive unit) 71 Main body (support part) 73 First Sensor 74 Second Sensor 75 3rd Sensor 81 Light emitting part 82 Light receiving section 100 FOUP (container) 113L Support part (2nd support part) 113R Support part (1st support part) A optical axis W Wafer (substrate) Wb end face Wb1 1st part Wb2 2nd part Wb3 3rd part

Claims

1. A base part whose installation position is fixed; a placement section attached to the base section, on which a container for accommodating a plurality of substrates arranged vertically is placed; a scanner unit configured to be able to detect the plurality of substrates contained in the container; a determination unit configured to be able to execute a determination regarding a state of each of the plurality of substrates detected by the scanner unit, The scanner unit includes: the container is placed on the placement section and a fixed state in which an angle of the container with respect to the base section about a vertical axis is fixed is maintained, the device is configured to be able to detect a first portion, a second portion and a third portion of the end face that are arranged apart from each other in an extension direction of the end face of each of the plurality of substrates, The determination unit is determining whether each substrate is properly accommodated in the container by using information on a first position, which is a position of the first portion in the vertical direction, and information on a second position, which is a 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 scanner unit includes: A first sensor configured to be able to detect the first portion; a second sensor separate from the first sensor configured to detect the second portion; a third sensor configured to detect the third portion and separate from the first sensor and the second sensor; a support portion supporting the first sensor, the second sensor, and the third sensor; 2. The load port according to claim 1, further comprising a drive unit configured to be able to drive and move the support unit in a vertical direction.

3. When the container is in the fixed state, a first support portion for supporting each of the plurality of substrates within the container is disposed on one side of a center of the container in a predetermined container width direction perpendicular to a vertical direction; a second support portion for supporting each of the plurality of substrates within the container is disposed on the other side of the center of the container in the container width direction; the first portion is disposed closer to the first support portion than the center of the container in the container width direction, The second portion is disposed closer to the second support portion than the center of the container in the container width direction, 3. The load port according to claim 1, wherein the third portion is disposed between the first portion and the second portion in the container width direction.

4. The scanner unit includes: 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; 3. The load port according to claim 1, further comprising an angle adjustment unit configured to adjust an angle of the optical axis of the detection light emitted from the light emitting unit about a vertical axis.

5. the plurality of substrates includes a plurality of wafers that are semiconductor substrates; 5. The load port according to claim 4, wherein the reflective optical sensor is disposed so that the optical axis is perpendicular to the end face of each of the plurality of substrates.

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