JP2010021257A - Wafer alignment device and wafer transfer device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer-gripping-type wafer alignment device that can detect the notch position, with stable high-speed throughput and that realizes this by effectively utilizing a conventional notch detecting means. <P>SOLUTION: A device for executing alignment of a wafer is equipped with a notch detecting means provided at the contact part of each grip arm 10, 20 in contact with the outer peripheral edge of a wafer so as to detect a notch at the outer peripheral edge of the wafer, when the notch is located at the contact part of the grip arm. When there is the grip arm having the notch detecting means, detecting the notch from among the plurality of notch detecting means, the device has a release mechanism for releasing the wafer-gripping state of the grip arm having at least the notch detecting means detecting the notch, and a maintaining mechanism for maintaining the gripping state, with respect to the wafer of one or more grip arms other than the grip arm whose wafer gripping state is released. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wafer alignment apparatus for positioning a wafer based on a notch position or the like on the outer periphery of a wafer in transporting a wafer such as a mini-environment apparatus used for semiconductor manufacturing or inspection.

  In semiconductor manufacturing equipment, inspection equipment, etc. used in semiconductor manufacturing plants, the wafer center / notch position, etc. is detected from the wafer outer shape data while the wafer is being transported from the storage container into the equipment body. A pre-alignment apparatus that performs alignment or the like (generally referred to as a pre-alignment apparatus with respect to an alignment apparatus used when processing a wafer or mounting a component in a semiconductor manufacturing apparatus or the like) is used as alignment means.

  The pre-alignment apparatus includes an edge detection unit for acquiring the outer peripheral shape of the wafer, a rotation mechanism unit for aligning the detection notch position, and a control function unit for controlling and calculating each mechanism. There is a wide variety of methods in which the outer periphery shape is acquired by an edge detection unit such as a line sensor, the notch shape feature is detected from the wafer outer periphery data by the control function unit, and the rotation mechanism unit performs alignment based on the detected notch position. Known and realized.

  Conventionally, in wafer transfer devices such as semiconductor manufacturing equipment and inspection equipment, the method of adsorbing and holding the back surface of the wafer as the wafer holding method at the time of wafer transfer occupies the mainstream. Adsorption was the mainstream.

  However, in recent years, the influence of contamination on the back surface of the wafer has been regarded as a problem, and a method of gripping the outer periphery of the wafer, which replaces the back surface adsorption method, is gradually increasing, and the pre-alignment apparatus tends to adopt the same wafer holding method. It is in.

  In the conventional wafer gripping type pre-alignment device, when the gripping mechanism that grips the outer periphery of the wafer overlaps with the notch position, the notch position cannot be detected from the acquired wafer periphery data, and the gripper is re-gripped so that it does not overlap. It is known that throughput is reduced because of re-detection. In order to solve this problem, a pre-alignment device (for example, see Patent Document 1) in which the spot diameter of a detection sensor for detecting the outer peripheral shape of the wafer is devised, or a gripping claw that is a contact portion with the edge of the wafer outer periphery of the gripping mechanism portion There is a pre-alignment apparatus that realizes notch alignment without re-wafering the wafer by devising the shape (for example, see Patent Document 2).

JP 2003-243294 A JP 2007-287729 A

  However, in the pre-alignment apparatus in which the spot diameter of the detection sensor of the wafer outer peripheral shape is devised, it is necessary to reduce the detection sensor beam diameter of the edge detection unit that acquires the wafer outer peripheral shape. For this reason, the edge detection section of the outer periphery of the wafer, such as a line sensor, cannot be used in the conventional backside suction holding method, and the range of edge detection is narrowed by the aperture of the beam diameter, and the notch-shaped features (position, etc.) Becomes difficult to detect.

  In the pre-alignment device with the above-described gripping claw shape, the wafer contact part of the gripping mechanism overlaps inside the notch shape of the wafer outer periphery data, and the notch feature value changes when combined with the notch shape. It becomes difficult to detect the feature (position) of the shape.

  That is, in the conventional pre-alignment apparatus, an important part in the pre-alignment apparatus in which the notch position is detected from the wafer outer periphery data using the detection means, and the detection means employed in the conventional back surface suction holding method. In addition, the detection processing method cannot be applied, and a new means for detecting the edge (notch shape) of the wafer is required.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to detect a notch position with a stable high-speed throughput, and to use a conventional wafer-holding pre-alignment apparatus that can be easily realized by effectively using a conventional notch detection means. Provided wafer transfer device.

  In order to achieve the above object, a wafer alignment apparatus according to the present invention includes a plurality of gripping arms that grip a wafer at its outer periphery, an edge detection unit that acquires the position of a notch formed at the outer periphery of the wafer, and a grip A rotation mechanism for rotating the wafer, and aligning the wafer based on the acquired notch position, wherein a contact portion of each gripping arm that contacts the outer periphery of the wafer When a peripheral notch is at the position of the contact portion of the gripping arm, notch detection means for detecting the notch is provided, and the alignment device detects notch of the notch detection means. If there is a gripping arm having a notch detecting means for detecting at least this notch, A release mechanism for releasing the holding state of the wafer, and has a maintenance mechanism for maintaining the gripping state for the wafer of one or more gripping arms except gripping arm is released the gripping state. Moreover, the wafer conveyance apparatus which concerns on this invention is equipped with said wafer alignment apparatus.

  According to the present invention, the position of the notch can be detected with a stable high-speed throughput in the wafer holding type pre-alignment apparatus, and can be easily realized by effectively using the conventional detection means.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a side view showing a configuration of a wafer alignment apparatus (pre-alignment apparatus) of the present embodiment, and FIG. 2 is a top view thereof. As shown in FIG. 1, the pre-alignment apparatus includes a plurality of gripping arms 10 (grip mechanism units) that grip the wafer 1 at the position of its outer peripheral edge (edge) 1 a, and a rotation mechanism unit 30 that rotates the gripping arms 10. , An edge detection unit 2 that acquires the outer peripheral shape of the wafer 1, and a control unit (not shown) that performs processing of acquired data acquired by the edge detection unit 2 and drive control of each mechanism such as each gripping mechanism unit / rotation mechanism unit 30. Z)). For example, a known optical line sensor is used as the edge detection unit 2. The grip arm 10 and the rotation mechanism unit 30 are provided on the apparatus base 3. Each gripping arm 10 includes an arm base 11 connected to the rotation mechanism 30, an arm 12 extending from the arm base 11 to the outer peripheral edge 1 a of the wafer 1, and a wafer 1 provided at the tip of the arm 12. The contact portion 50 is in contact with the contact portion 50.

  As shown in FIG. 2, the plurality of gripping arms 10 are arranged at approximately equal intervals in the circumferential direction of the wafer 1, and three gripping arms 10 a, 10 b, 10 c (20 a, 20 b, 20 c) that are not adjacent to each other are arranged. One set and three gripping arms are interlocked and provided with a mechanism capable of gripping and releasing operations (described later) in units of sets. The gripping arms 10 do not need to be three in one set, and may be two or four or more, and it is not necessary to be in two sets as long as the wafer 1 can be gripped without dropping. For example, it is sufficient if the wafer 1 can be gripped without dropping even with a configuration of two sets and four sets. Further, it may be a mechanism that performs the gripping / opening operation for each gripping arm 10 instead of the operation in units of groups.

  FIG. 6 is a partial side view showing a grip / release state of the grip arm 10. As shown in FIG. 6, each gripping arm 10 is connected to the rotation mechanism unit 30 when the wafer is gripped and rotates together with the rotation mechanism unit 30, and is separated from the rotation mechanism unit 30 when the wafer is opened. Even if the part 30 rotates, it does not rotate.

  Specifically, as shown in FIG. 7, on the side surface of the rotation mechanism portion 30, a connection portion 34 for connecting the grip arm 10, and the grip arm 10 side provided in the connection portion 34 (arrow 31 a in the figure). And a connecting arm 31 that can reciprocate. A latch 32 and a connection actuator 33 that drives the latch 32 are provided at the tip of the connecting arm 31. The latch 32 rotates around the tip of the movable arm portion 31 by driving the connection portion actuator 33 (arrow 32a in the figure). A connection port 14 connected to the connecting arm 31 is formed on the inner side (rotation mechanism 30 side) 11 a of the grip arm base 11. A locking projection 14 a that engages with the latch 33 of the connecting arm 31 is formed in the connection port 14. As the latch 32 rotates, the movable arm 31 is connected (locked) to or disconnected from the grip arm 10. A slider 15 is interposed between the gripping arm 10 and the apparatus base 3, and the gripping arm 10 slides on the apparatus base 3.

  The operation of the gripping arm 10 from the open (disconnected) state to the gripping state will be described. The latch 32 is inserted into the connection port 14 by moving the connecting arm 31 to the gripping arm 10 side. After the insertion, the actuator 33 is driven to engage the latch 32 with the locking projection 14a, and the gripping arm 10 is locked as shown in FIG. After locking, the contact arm 50 of the arm gripping part 10 grips the outer peripheral edge 11 a of the wafer 1 by moving the connecting arm 31 to the rotation mechanism part 30 side. On the other hand, the operation of releasing the holding arm 10 from the holding state may be performed in the reverse order of the operation of changing the holding state from the opening state to the holding state.

  The gripping arm 10 holds the outer peripheral edge 1a of the wafer 1 by pressing each gripping arm 10 toward the center in the radial direction of the wafer, and opens the wafer outer peripheral edge 1a by performing the reverse operation. A mechanism for supporting the wafer may be provided separately from the gripping arm 10 in order to prevent the wafer from dropping when the wafer 1 is delivered from another apparatus. In addition, a device for detecting the presence or absence of a wafer may be provided separately and used for wafer confirmation.

  3 and 4 are enlarged views of a main part of a portion where the grip arm 10 and the wafer 1 are in contact, FIG. 3 is a side view thereof, and FIG. 4 is a top view thereof.

  The contact portions 50 of the plurality of gripping arms 10 are each formed in a claw shape so as to grip the wafer 1 by pushing the wafer outer peripheral edge 1 a toward the center of the wafer 1. Notch detection means (contact detection unit 55) is provided inside the contact units 50. That is, the contact detection part 55 provided in the wafer outer periphery 50 contacts the wafer outer periphery 1a.

  The contact detection unit 55 has a function of detecting the shape of the wafer outer peripheral edge 1a in the wafer horizontal direction. For example, the contact detection unit 55 is configured by means (for example, a pressure sensor or the like) that electrically acquires the pressure applied to the wafer outer peripheral edge 1a. The contact detector 55 detects a certain pressure when contacting the wafer outer peripheral edge 1a, but does not detect the pressure at the notch 1b. That is, the contact detection unit 55 can identify the position of the notch 1b by detecting the discontinuity of continuous pressure detection, and can detect the interference between the notch 1b and the grip arm 20c.

However, the relationship between the notch width Wn and the width of the wafer contact portion width Wt is
Wn <Wt
It is desirable that

  Even if the relationship between the width of the notch width Wn and the width of the wafer contact portion Wt does not satisfy the above equation (1), the notch may be detected simply by detecting the presence or absence of contact.

  Next, a wafer pre-alignment method using the present pre-alignment apparatus will be described. First, the wafer 1 is held with the six holding arms 10 (10a to 10c, 20a to 20c) held. Next, the presence or absence of the notch 1b is detected by the contact detection unit 55 of each gripping arm 10.

  When the notch 1b is not detected, the notch 1b and the gripping arm 10 are not overlapped. Therefore, the rotation mechanism unit 30 is driven to rotate the wafer 1 and the edge detection unit 2 detects the wafer outer peripheral shape data.

  On the other hand, when the notch 1b is detected by the contact detection unit 55, as shown in FIG. 5, a set of three grip arms 20a to 20c including the contact detection unit 55 that has detected the notch 1b are simultaneously released from the gripping state ( Disconnect). At this time, the wafer 1 can be held only by the pair of gripping arms 10a to 10c that are in a gripping state (not open). As described above, when the gripping arm 10 is in the gripping state, the gripping arm 10 is connected to the rotating mechanism unit 30. By rotating the rotating mechanism 30, the gripping arms 10a to 10c are also rotated, and the gripping arms 10a to 10c are rotated. The held wafer 1 can be rotated. As the wafer 1 rotates, the edge detection unit 2 interlocks to acquire the shape of the wafer outer peripheral edge 1a, and specifies the notch shape using the acquired wafer outer peripheral shape data. That is, the pre-alignment apparatus detects the overlap of the gripping arm 10 with the notch 1b in advance, and the gripping arms 20a to 20c in the opened state are disconnected from the rotation mechanism unit 30, and at the time of rotation when acquiring the wafer outer shape data The shape of the wafer outer peripheral edge 1a can be acquired without interfering with the edge detection unit 2 because it does not rotate in conjunction with it.

  Further, when the overlap between the gripping arm 10 and the notch 1b is detected, the search for the notch position can be improved by starting the search from the wafer outer periphery data in the vicinity of the gripping arm 20c that has detected the notch 1b. .

  As described above, according to the present pre-alignment apparatus, by detecting and avoiding the overlap between the notch position and the grip arm position in advance, it is possible to detect the notch position from the wafer outer periphery data without the obstruction factor of grip arm interference. In addition, pre-alignment can be easily realized by using the same detection means and detection processing method (detection algorithm) as the wafer back surface suction method for the notch position detection processing from the wafer outer periphery data.

  Next, the operation flow of the pre-alignment apparatus of the present embodiment will be described in comparison with the operation flow of the conventional pre-alignment apparatus.

  FIG. 9 is a flowchart showing the operation (control method) of the conventional pre-alignment apparatus and the operation of the pre-alignment apparatus of the present invention. As shown in FIG. 9, in the operation 500 in the conventional pre-alignment apparatus and the operation 600 in the pre-alignment apparatus of the present embodiment, the wafer to be pre-aligned is first transferred to the holding mechanism unit from some other apparatus and is held. (Step 100) is performed. At this time, the wafer transfer source is a device such as a transfer robot or a person.

  In the conventional pre-alignment apparatus operation 500, when the wafer 1 is grasped, the rotation of the wafer 1 is started (step 110), the wafer outer periphery data is acquired in conjunction with the rotation (step 120), and the wafer rotation is finished (step 130). After that, the notch position is searched from the outer circumference data (step 140). At this time, it is sufficient that the notch position can be detected without any problem. However, when the notch overlaps with the gripping arm and the notch detection fails (step 200), the gripping position is changed by gripping the wafer 1 again (step 210). ). After changing the holding position, the wafer is rotated again (step 220), the wafer outer periphery data is acquired (step 230), and the notch position is detected again after completion of the rotation of the wafer (step 240) (step 250). That is, in the conventional control method 500, as the avoidance process when the grip arm and the notch position overlap, the method of re-detecting the notch by re-gripping the wafer at a different position increases the throughput.

  After detection of the notch position, the wafer is aligned by rotating the wafer to the notch determination position (step 150), and the wafer is transferred to another apparatus (step 160).

  In the operation 600 of the pre-alignment apparatus of the present embodiment, after the wafer 1 is transferred to the gripping mechanism (the plurality of gripping arms 10), the overlap between the gripping arm 10 and the notch 1b is detected by the method described above, and the gripping arm is detected. By releasing 20c (step 300), the saving process (steps 200 to 250) when the notch positions overlap in the conventional control method can be omitted, and a reduction in throughput can be prevented.

In the operation 600 of this embodiment, steps 200 to 250 are performed for the purpose of changing the gripping position when trying to re-detect, for example, for the purpose other than avoiding the overlap between the gripping arm 10 and the notch position. You may add the process. In this case, by detecting the overlap between the grip arm 10 and the notch position and performing the grip arm avoiding process, a stable and high-throughput grip-type pre-alignment apparatus can be realized.
(Second Embodiment)
The basic configuration of the pre-alignment apparatus of the present embodiment is almost the same as the apparatus of the previous embodiment, but this embodiment is different from the apparatus of the previous embodiment in the configuration of the gripping arm.

  FIG. 10A is an enlarged side view of the main part showing the wafer gripping state of the pre-alignment apparatus of the present embodiment, and FIG. 10B is an enlarged side view of the main part showing the wafer opened state. As shown in FIGS. 10 (a) and 10 (b), the arm portion 41 of the gripping arm 40 is tilted so that the wafer contact portion 50 is separated from the wafer outer peripheral edge 1a (arrow 44a in the figure). A (hinge) 42 and an actuator for driving the joint portion 42 are provided. Further, the base 43 of the gripping arm 40 is always connected to the rotation mechanism unit 30, but when the wafer 1 is gripped or released, the movable part 44 of the gripping arm 40 (from the joint to the front outer periphery) 44 is the wafer. It is configured to be movable in the wafer radial direction (arrow 43a in the figure) so that a gripping / opening operation can be performed without damaging 1.

During the gripping operation of the gripping arm 40, the movable portion 44 is set to the gripping position, and then the base 43 is moved to the rotation mechanism portion 30 side to grip the wafer 1. When the gripping arm 40 is in an open state, the base 43 is moved in a direction away from the rotation mechanism unit 30, and then the joint unit 42 is driven by the actuator to tilt the movable unit 44 and stored under the wafer 1. In this apparatus, when the movable part 44 of the grip arm group 40 that has detected the notch by the contact detection unit 55 falls down below the wafer 1, the grip arm 40 grips and rotates the wafer 1. Interference with the gripping arm 40 and the edge detector 2 can be avoided.
(Third embodiment)
The basic configuration of the pre-alignment apparatus according to the present embodiment is almost the same as the apparatus according to the first and second embodiments, but in the present embodiment, the configuration of the rotation mechanism and the arrangement of the gripping arms are the previous embodiments. Different from the device.

  FIG. 11 is a diagram showing the configuration of the pre-alignment apparatus of the present embodiment, where (a) is a plan view thereof and (b) is a side view thereof. As shown in FIGS. 11A and 11B, the rotation mechanism unit 30 includes a rotating disk unit 35 that rotates on the apparatus base 3. The rotating disk portion 35 is formed with a diameter larger than the diameter of the wafer 1. The gripping arm 10 (the base 11, the arm 12, and the contact 50 are all) is disposed on the rotating disk portion 35 outside the wafer 1. In addition, the gripping arms 15a to 15c and 25a to 25c are provided with actuators for moving the gripping arms 15a to 15c and 25a to 25c in the wafer radial direction.

  In the drawing, grip arms 15a to 15c described on the inner side indicate a grip state, and grip arms 25a to 25c described on the outer side indicate an open state.

  When the gripping arm 10 is gripping or releasing, the actuator is driven to move the gripping arm inward (extend) to enter the gripping state. When an overlap between the gripping arm and the notch is detected, the gripping arm is moved outward. To open (shrink).

  When the rotation mechanism unit 30 is rotated, the gripping arms 15 a to 15 c in the wafer gripping state and the gripping arms 25 a to 25 c in the wafer opening state rotate together, but the gripping arm 10 in the open state 25 a to 25 c is outside the edge detection unit 2. , The gripping arms 25 a to 25 c do not interfere with the edge detection unit 2. The edge detection unit is divided and fixed above and below the wafer 1 as in 2a and 2b, so that the rotational movement of the gripping arm is not hindered regardless of the gripping / opening state of the gripping arm 10.

In the present embodiment, the rotation mechanism unit 30 and the gripping arms 15a to 15c and 25a to 25c are configured to rotate simultaneously. However, a pre-alignment device that detects the notch position without an obstruction factor of gripping arm interference can be realized. .
(Fourth embodiment)
The basic configuration of the pre-alignment apparatus of the present embodiment is almost the same as that of the apparatus of the previous embodiment, but in this embodiment, unlike the pressure-sensitive sensor that is the notch detection means of the first embodiment, It differs in that it has notch detection means of the formula.

  FIG. 12 is a side view of a contact portion between the grip arm 10 and the wafer outer peripheral edge 1a, and FIG. 13 is a top view thereof. As shown in FIGS. 12 and 13, the notch detection means 61 provided at the tip of the gripping arm 10 supports a plurality of claw portions 65 that are in contact with the outer peripheral edge 1 a of the wafer 1 and the claw portions 65, respectively, in the wafer radial direction. And a plurality of movable holding pins 60. The nail | claw part 65 is formed with resin which is easy to process and is hard to deform | transform, for example, such as PEEK (polyetheretherketone) resin. The notch detection unit 61 further includes an actuator that moves the grip pin 60 and a unit that detects the amount of movement of the grip pin 60.

  When the gripping arm 10 grips the wafer 1, all the gripping pins 60 move in the wafer center direction with the claw portions 65 contacting the outer peripheral edge 1 a of the wafer 1. The presence or absence of the notch 1b can be detected based on the amount of movement of the grip pin 60.

In order to detect the presence or absence of the notch 1b, the notch detection means 61 has a relationship between the wafer contact width Wt, the notch width Wn and the grip pin width Wc of the grip arm.
Wc <Wn <Wt
To be configured.

Further, it is desirable that the grip pin interval Ws is such that a plurality of Wc can be arranged within the notch width Wn, and when the number of grip pins 60 entering one notch 1b is M,
Wc × M + Ws × (M−1) <Wn
It is good to comprise so that.

  When the wafer 1 is held by the holding arm 10 provided with such a shape detection unit 61, the claw portion 65 moves along the shape of the outer peripheral edge 1a of the wafer. By detecting the difference in the maximum notch depth Ln with the length Lc2 along the outer periphery of the wafer, it is possible to detect the overlap between the grip arm 10 and the notch 1b. At this time, the width depending on the notch width can be estimated from the grasping pin interval Ws and the number of grasping pins, which are known in advance, and used for notch overlap determination.

  In this embodiment, the notch detection means 61 is of a type that pulls the holding pins 60 toward the wafer center, but may be configured to push from the outside of the wafer, and depending on the amount of movement when the claw portion 65 contacts the wafer outer peripheral edge 1a. If the shape of the wafer outer peripheral edge 1a can be detected, the gripping pin 60 does not stick to the expansion / contraction (movement) direction.

  As described above, in the gripping type pre-alignment apparatus, it is possible to realize the pre-alignment apparatus that detects the overlap between the grip arm and the notch position by detecting the wafer outer periphery data using the movement amount of the grip pin and performs the avoidance process. it can.

In the first to fourth embodiments, the notch detection means detects the shape based on electrical pressure such as a pressure-sensitive sensor, and detects the shape based on the mechanical movement amount of the grip pin or the like. However, as another notch detection means, a means for imaging the contact shape between the outer peripheral edge 1 a of the wafer 1 and the grip arm 10 may be provided in the grip arm 10. Further, the configuration of the gripping arm and the like for gripping / opening the wafer 1 and the configuration of the notch detection means are not limited to the above-described combinations.
(Wafer transfer device)
A wafer transfer apparatus (mini-environment apparatus) provided with the wafer alignment apparatus according to the present invention will be described.

  FIG. 14 is a schematic diagram showing the configuration of the wafer transfer apparatus. As shown in FIG. 14, the wafer transfer apparatus includes a casing 70, a load port unit 72 in which a container 71 (cassette or FOUP (Front Opening Unified Pod)) in which the wafer 1 is stored, a notch alignment, and the like. The wafer 1 is placed between the intended pre-alignment apparatus 73, the apparatus connection portion 74 connected to the semiconductor manufacturing apparatus or inspection apparatus that is the transfer destination of the wafer 1, and the container 71, the pre-alignment apparatus 73, and the apparatus connection section 74. A transport robot 75 is provided. The transport device includes an FFU (Fun Filter Unit) and the like, thereby maintaining the container 71 and the housing 70 in a clean environment. The pre-alignment apparatus 73 is the pre-alignment apparatus described in the first to fourth embodiments. At least one or more (four in the figure) containers 71 are installed in the load port unit 72, and the number of installations is appropriately determined depending on the use environment.

  Regarding the transfer of the wafer 1, first, the transfer robot 75 acquires the wafer 1 from the container 71 installed in the load port unit 72. The acquired wafer 1 is transferred to the pre-alignment device 73, the wafer 71 is aligned as described above, and is carried to the device connection portion 74 by the transfer robot 75, and the semiconductor device is opened from the opening 77 of the device connection portion 74. It is conveyed in. The wafer 1 returned from the semiconductor device is taken out by the transfer robot 75 at the apparatus connection unit 74 and transferred into the container 71 of the load port unit 72. In the middle of returning the wafer 1 from the semiconductor device to the load port unit 72, it is possible to store the wafer 1 in the container after adjusting the notch position via the pre-alignment device 73.

  As described above, the wafer transfer apparatus can transfer the wafer 1 in a state where the pre-alignment apparatus 73 matches the notch position. The wafer transfer apparatus according to the present embodiment uses the pre-alignment apparatus 73 described above, so that the wafer 1 can be aligned and transferred without lowering the throughput.

  As described above, the present invention is not limited to the above-described embodiments, and various other ones are assumed.

1 is a side view showing a pre-alignment apparatus according to a first embodiment of the present invention. It is a top view of the pre-alignment apparatus of FIG. It is a side view which shows a holding arm and a wafer contact part in the pre-alignment apparatus of FIG. It is a top view which shows a holding arm and a wafer contact part in the pre-alignment apparatus of FIG. It is a top view which shows the holding state and open state of a holding arm. It is a side view which shows the positional relationship of the holding | grip mechanism part and rotation mechanism part of 1st Embodiment. It is a side view which shows the structure of the holding | grip mechanism part and rotation mechanism part of 1st Embodiment. It is a partially transparent side view which shows the time of engagement with the holding | grip mechanism part and rotation mechanism part of FIG. It is a flowchart which each shows the control system of the conventional pre-alignment apparatus, and the control system of the pre-alignment apparatus of this invention. The pre-alignment apparatus of 2nd Embodiment is shown, (a) is a principal part side view of a wafer holding state, (b) is a principal part side view of a wafer open state. It is a figure which shows the pre-alignment apparatus of 3rd Embodiment, (a) is the top view, (b) is the sectional drawing. It is a side view which shows the holding | grip mechanism part of the pre-alignment apparatus of 4th Embodiment. It is a top view which shows the holding | grip mechanism part of the pre-alignment apparatus of 4th Embodiment. It is a schematic block diagram which shows the structure of a wafer conveyance apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 1a Wafer outer periphery 1b Notch 2 Edge detection part 3 Apparatus base 10 Grasp arm 30 Rotation mechanism part 31 Connection arm 50 Wafer contact part 55 Contact detection part 60 Grasping pin 65 Claw part

Claims (10)

The acquired notch includes a plurality of gripping arms for gripping the wafer at its outer periphery, an edge detection unit for acquiring the position of the notch formed on the outer periphery of the wafer, and a rotation mechanism unit for rotating the gripped wafer. In the wafer alignment apparatus for aligning the wafer based on the position,
The contact portion of each gripping arm that contacts the outer periphery of the wafer is provided with notch detection means for detecting the notch when the notch of the outer periphery of the wafer is at the position of the contact portion of the gripping arm,
When there is a gripping arm having notch detection means for detecting the notch among the notch detection means, at least a release mechanism for releasing the wafer gripping state of the grip arm having the notch detection means for detecting the notch; And a maintenance mechanism that maintains the gripping state of the one or more gripping arms excluding the gripping arm released from the gripping state with respect to the wafer. The wafer alignment apparatus according to claim 1,
Two sets of the gripping arms are provided,
In the case where there is a gripping arm having a notch detection means that detects the notch among the notch detection means, the release mechanism is configured to remove the wafer by the pair of gripping arms to which the gripping arm having the notch detection means that detects the notch belongs. Release the gripping state,
The other set of gripping arms is configured to maintain a gripping state with respect to the wafer via the maintaining mechanism.   3. The wafer alignment apparatus according to claim 1, wherein a gripping arm in a gripping state of the wafer is connected to the rotation mechanism unit and rotates together with the rotation mechanism unit, while gripping in a state of not gripping the wafer. The wafer alignment apparatus in which the arm is configured not to rotate by being disconnected from the rotation mechanism.   4. The wafer alignment apparatus according to claim 3, wherein the rotation mechanism is provided with a connecting arm portion that reciprocates toward the gripping arm, and the tip of the connecting arm portion and the gripping arm are provided with the rotation mechanism portion and the gripping arm. Wafer alignment apparatus provided with a connecting portion for connecting the two to each other.   3. The wafer alignment apparatus according to claim 1, wherein the gripping arm includes a joint portion that tilts so that the contact portion side is separated from the outer peripheral edge of the wafer, and an actuator that drives the joint portion.   3. The wafer alignment apparatus according to claim 1, wherein the rotation mechanism unit includes a rotating disk unit having a diameter larger than that of the wafer, and the gripping arm is disposed outside the wafer on the rotating disk unit. Wafer alignment device arranged to be movable in the radial direction.   The wafer alignment apparatus according to claim 1, wherein the notch detection unit is a unit that comes into contact with an outer peripheral edge of the wafer and electrically acquires a pressure.   7. The wafer alignment apparatus according to claim 1, wherein the notch detection unit supports a plurality of claw portions that are in contact with the outer peripheral edge of the wafer and the claw portions, and is movable in the wafer radial direction. A wafer alignment apparatus, which has a plurality of grip pins, and is a means for mechanically detecting the notches based on a movement amount of the grip pins.   7. The wafer alignment apparatus according to claim 1, wherein the notch detection unit is a unit that images a contact shape between the gripping arm and the wafer.   10. The wafer transfer apparatus comprising: a container for storing a wafer; a wafer alignment apparatus for aligning a wafer; and a wafer transfer robot for transferring a wafer from the container to the alignment. A wafer transfer apparatus using the wafer alignment apparatus described above.

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