JP2008069433A - Method of confirming aligning of wafer chuck and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of confirming aligning of wafer chuck which confirms whether a wafer has been chucked as being designed and corrects a little angle deviation of the wafer, and also to provide a device therefor. <P>SOLUTION: The wafer chuck is equipped with: a chuck base 5 installed on a robot hand 1; a pair of wafer arms 7 and 7 installed on the chuck base 5 and arranged left-right symmetrically with respect to the center extension line 1c of the robot hand; fingers 9 and 9 installed on the wafer arms and chucking a wafer Wf; and an arm opening/closing cylinder 15 for opening/closing the pair of wafer arms. The wafer chuck is further equipped with: a notch guide 13 provided between the pair of wafer arms 7 and 7 of the chuck base 5 to be fitted into a wafer notch 20 and arranged on the center extension line 1c of the robot hand 1; and a means for measuring the chucking interval between the both wafer arms. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer chuck used when a wafer is transported and preprocessed or electroplated, and more specifically, whether or not the wafer is held in a direction as designed. The present invention relates to a wafer chuck aligning confirmation method and apparatus therefor.

A thin film is attached to the plated surface of the wafer, and this thin film is automatically generated through a process as shown in FIG. That is,
The wafer wf stored in the wafer cassette 100 is carried to the orientation aligner 104 via the load robot 102, and alignment work is performed. In this process, the wafer notch is oriented in the design direction (alignment).

  The aligned wafer wf is sandwiched between the wafer chucks 108 of the transfer robot 106, transferred to the preprocessing apparatus 110, and placed on the wafer holder 112, and then preprocessed.

  The wafer chuck 108 includes a chuck base provided on the robot hand, a pair of wafer arms provided on the chuck base and arranged symmetrically with respect to the center line of the chuck base, and provided on the wafer arm. And a cylinder that opens and closes the pair of wafer arms, and the wafer is clamped by driving the cylinders and sliding the wafer arms. Or cancel.

  After completion of the pre-processing, the wafer wf is sandwiched between the wafer chucks 115 of the transfer robot 114, transferred to the electroplating apparatus 116, and placed on the wafer holder 118. The wafer chuck 115 has the same structure as the wafer chuck 108.

  Next, the wafer holder 118 is moved up and fitted into the bottom 120a fitting hole of the plating tank 120, and the bottom 120a is sealed. In this state, the plating bath 120 is filled with a plating solution, and when power is supplied to the anode 122 and the cathode of the cathode holder 124, the wafer wf is plated.

  At this time, a magnetic field is formed by the magnet 126 on the bottom 120 a side of the plating tank 120. Therefore, the wafer wf is positioned in the magnetic field. However, if the direction of the notch or orientation flat of the wafer is the design direction, the direction of the magnetic field matches the direction of the pattern on the wafer, and normal. The film is formed.

  In the conventional example, even when the wafer is aligned with the orientation aligner, the wafer may rotate when the wafer is sandwiched, and the position of the wafer notch may be displaced (angle deviation). When electroplating a wafer with an angular deviation in this way, the direction of the magnetic field and the direction of the pattern on the wafer become inconsistent, so that the film formation as designed cannot be obtained. For this reason, all chips on the wafer are defective and must be discarded.

  In view of the above circumstances, an object of the present invention is to confirm whether or not a wafer can be clamped as designed. Another object is to be able to correct the wafer if it is slightly misaligned.

  The present invention relates to a wafer chuck comprising a chuck base provided on a robot hand and a pair of openable and closable wafer arms provided on the chuck base; provided between the two wafer arms of the chuck base. And a guide member that contacts the notch or orientation flat of the wafer, and means for measuring a holding interval between the both wafer arms.

  The present invention provides a chuck base provided in a robot hand, a pair of wafer arms provided on the chuck base and arranged symmetrically with respect to a central extension line of the robot hand, and provided on the wafer arm. In a wafer chuck comprising a finger for holding a wafer and a driving means for opening and closing the pair of wafer arms; provided between both wafer arms of the chuck base and contacting a notch or an orientation flat of the wafer A guide member, comprising: a guide member disposed on a center line of the robot hand; and means for measuring a holding interval between the two wafer arms.

  The guide member of the present invention is a notch guide or an orientation flat guide. The holding interval of the present invention is characterized in that it is an interval between fingers of both wafer arms or between holding portions.

  The present invention relates to a wafer chuck comprising a chuck base provided on a robot hand and a pair of openable and closable wafer arms provided on the chuck base; provided between the two wafer arms of the chuck base. Alignment of a wafer using a wafer chuck alignment confirmation device comprising: a guide member that contacts a notch or orientation flat of a wafer; and a means for measuring a clamping interval between the two wafer arms. A step of moving the robot hand to a design position, causing the opened wafer arm to face the wafer on the wafer holder, and moving the robot hand in the direction of the central extension thereof, Insert the component into the wafer notch or orientation flat. A step of bringing the guide member into contact with a notch or an orientation flat of the wafer, a step of sliding the both wafer arms inward to close the wafer chuck, and holding the wafer And a step of measuring a holding interval between the wafer arms and a step of comparing the measured holding interval with a design holding interval.

  The guide member according to the present invention is a notch guide having a triangular portion at a tip, and when the triangular portion of the notch guide comes into contact with a part of the V-shaped notch, the notch guide is further fixed. The wafer is rotated in the direction and is inserted into the notch. The guide member of the present invention is an orientation flat guide, and when the horizontal portion of the orientation guide abuts a part of the orientation flat, the guide is further advanced in the same direction to rotate the wafer. It is made to move and surface-contacts with said orientation flat.

The present invention comprises a guide member provided between the wafer arms of the chuck base and abutted against the notch or orientation flat of the wafer, and means for measuring the clamping interval between the wafer arms. Therefore, it is possible to detect whether or not it is aligned by measuring the sandwiching interval in the closed state and comparing it with the design sandwiching interval.
Even if the wafer has a slight angle shift, the angle shift can be corrected by the guide member coming into contact with the notch or orientation of the wafer.

A first embodiment of the present invention will be described with reference to FIGS.
A wafer chuck 3 is provided on the robot hand 1 of the wafer transfer robot. A pair of wafer arms 7 and 7 are provided on the chuck base 5 of the wafer chuck 3 so as to face each other.

  The wafer arms 7 and 7 are arranged symmetrically with respect to the center extension line 1c of the robot hand 1, and two fingers 9 and 9 are provided at predetermined intervals on each arm 7 and 7, respectively. Is provided. The fins 9 and 9 protrude below the wafer arms 7 and 7, and wafer locking portions 11 and 11 are provided at the lower ends thereof.

  A notch guide 13 as a guide member is provided between the wafer arms 7 and 7 of the chuck base 5. The notch guide 13 is a member fitted into a V-shaped notch 20 formed on the wafer wf. As shown in FIG. 1, the base end portion 13a having a rectangular shape in plan view and the base end portion are shown. 13a, a trapezoidal portion 13b that continues to 13a, and a triangular portion 13d that continues to the trapezoidal portion 13b via an outer peripheral end surface pressing portion 13c of the wafer. The triangular portion 13d is formed in a shape that can be fitted into the notch 20, for example, a triangle similar to the V-shaped wafer notch 20.

  A center line 13C of the notch guide 13 is located on the extension line 1c and is located between the pair of wafer arms 7 and 7. The notch guide 13 extends below the chuck base 5 and has a lower end located substantially on the same plane as the lower end of the finger 9 as shown in FIG.

The chuck base 5 is provided with means for opening and closing the wafer arms 7, for example, an arm opening / closing cylinder 15.
Although not shown in the drawings, means for measuring the holding interval between the fingers 9 and 9 of the wafer arms 7 and 7, for example, means for mechanically measuring the holding interval from the sliding distance of the cylinder 15, Is provided.

The operation of this embodiment will be described.
Normal (when aligned):
When the wafer processing step, for example, the preprocessing step is completed, the wafer transfer robot moves the robot hand 1 so that the wafer chuck 3 faces the wafer holder 22 of the preprocessing apparatus.

  This facing position is such that the center line 13C of the notch guide 13, the center 20p of the wafer notch 20, and the center p of the wafer wf are located on the center extension line 1c of the robot hand 1 in plan view.

  When the robot hand 1 is moved toward the center p of the wafer wf, the triangular portion 13d of the notch guide 13 is fitted into the notch 20 of the wafer. At this time, the pressing portion 13 is in contact with the outer peripheral end surface of the wafer wf and restricts the movement of the wafer wf.

  At this time, even if the center line 13C of the notch guide 13 does not completely coincide with the center 20p of the wafer notch 20, in the case of a slight angle shift, the angle shift can be corrected. That is, when the triangular portion 13d contacts a part of the inner surface of the V-shaped touch 20, when the robot hand 1 is further advanced in the same direction, the notch 20 is pushed by the triangular portion 13d. The guide notch 13 is inserted while the direction is corrected. Therefore, the notch 20 faces the direction as designed.

  Next, the arm opening / closing cylinder 15 is driven, and the opened wafer arms 7, 7 are slid inward to be in the closed state. Then, since the wafer locking portions 11 and 11 of the fingers 9 and 9 are locked to the outer peripheral end surface of the wafer wf, the wafer wf is pinched (chucked).

  As shown in FIG. 3, the value of the clamping interval L1 between the fingers 9 and 9 of both wafer arms 7 and 7 at this time is measured using the measuring means. Then, the measured value of the holding interval L1 is compared with the design holding interval, that is, the value of the holding interval L when it is held as designed using the comparison means. As this comparing means, for example, a comparator connected to an alarm device is used.

  When the notch guide 13 is fitted in the wafer guide 20, the position of the wafer notch is normal, and the measured clamping interval L1 is equal to the design clamping interval L. Therefore, in this case, since an abnormal signal is not output from the comparator to the alarm device, it can be confirmed that it is sandwiched (aligned) as designed.

Next, the robot hand 1 is rotated and the wafer chuck 3 is made to face a wafer holder (not shown) of the electroplating apparatus. Then, the robot hand 1 is lowered and the wafer arms 7 and 7 are slid to move the wafer. The chuck 3 is opened, and the wafer wf is placed on the wafer holder as designed.
After the wafer holder is raised and fitted into the bottom fitting hole of the plating tank, electroplating is performed while applying a magnetic field to the wafer.

Abnormal (when not aligned):
Even when the robot hand 1 is moved forward as described above, if the notch 20 of the wafer is shifted in angle as shown in FIG. 4, the triangular portion 13d of the notch guide 13 is a portion 21 away from the wafer notch 20. Cannot be fitted into the V-shaped notch 20.

  When the wafer arms 7 and 7 are slid in this state to close the wafer chuck 3, the position where the front-side fingers 9 a and 9 a are locked with the wafer is when the guide notch 13 is fitted in the notch 13. Compared to the position p, the position is closer to the center p of the wafer. Therefore, the clamping interval L2 between the fingers 9a, 9a is larger than the clamping interval L1, and is larger than the design clamping interval L. Therefore, when the clamping interval L2 is input to the comparator, an abnormal signal is output to the alarm device and an abnormal alarm is issued, so that it can be known that the alignment is not performed.

A second embodiment of the present invention will be described with reference to FIG. 5. In FIG. 5, the same reference numerals as those in FIGS. 1 to 4 have the same names and functions.
The difference between this embodiment and the above embodiment is that an orientation flat guide is used as a guide member.
This guide is used when an orientation flat is provided instead of the notch.

  The orientation flat guide 30 is formed at the base end portion 30a and the tip of the free end portion, is provided with a horizontal portion 30b that contacts the orientation flat 32 of the wafer, and is provided at both ends of the horizontal portion 30b. A pressing portion 30c in contact therewith.

In this embodiment, the robot hand 1 is slid in the direction of the center extension line and the wafer wf is held by the wafer chuck 3 in the same manner as in the previous embodiment.
When the sandwiched state (closed state) is in contact with the orientation flat 32 of the wafer wf and the horizontal portion 30b of the orientation flat guide 30 as shown in FIG. Is equal to the design clamping interval L. Therefore, since no abnormal signal is output from the comparator, it can be known that the comparator is normal, that is, aligned.

  On the other hand, as shown in FIG. 5A, when the horizontal portion 30b of the orientation flat guide 30 abuts on the portion 31 away from the orientation flat 32, the clamping interval L2 becomes larger than the clamping interval L1, and It becomes larger than the design clamping interval L. Therefore, an abnormal signal is output from the comparator, and it can be known that there is no abnormality, that is, no alignment.

A third embodiment of the present invention will be described with reference to FIG. 6. In FIG. 6, the same reference numerals as those in FIGS. 1 to 4 have the same names and functions.
The difference between this embodiment and the first embodiment is that contact sensors 35 and 36 are provided on the left and right contact surfaces of the triangular portion 13 a of the notch guide 13.

  In this embodiment, as indicated by a chain line, when the guide notch 13 is inserted into the notch 20, both sensors 35 and 36 output contact signals. Therefore, when the contact signal is output, the notch guide 13 is inserted into the notch 20, and the notch 20 is in the design direction. Therefore, it is possible to double-check the direction of the notch by further measuring the clamping interval.

A fourth embodiment of the present invention will be described with reference to FIG. 7. In FIG. 7, the same reference numerals as those in FIG. 5 have the same names and functions.
The difference between this embodiment and the second embodiment is that contact sensors 45 and 46 are provided on the horizontal portion 30 b of the orientation flat guide 30. The contact sensors 45 and 46 are provided symmetrically with respect to the center extension line 1 c of the robot hand 1.

  In this embodiment, as indicated by the chain line, when the orientation flat guide 30 comes into surface contact with the orientation flat 32, both sensors 45 and 46 output contact signals. Therefore, when the contact signal is output, the guide 30 comes into contact with the orientation flat 32 to come into surface contact, and the orientation flat 32 is in the design direction. Therefore, by further measuring the clamping interval, it is possible to double-check the orientation flat 32 direction.

The embodiment of the present invention is not limited to the above, and may be as follows, for example.
(1) Instead of providing a finger on a pair of wafer arms, a wafer clamping part is provided inside both wafer arms. In this case, the holding interval is the interval between both wafer arms (wafer holding portions). When measuring the holding interval, it is not always necessary to use the portion in contact with the wafer as a reference, and for example, the inner edge or the outer edge of the wafer arm can be used as a reference.

(2) Instead of using mechanical measurement means as the clamping interval measurement means, optical measurement means such as an optical sensor is used.
(3) The guide member is not necessarily fixed to the chuck base, and may be directed to the casing of the arm opening / closing cylinder, for example. Therefore, the chuck base to which the guide member is fixed includes the casing and the like in addition to the chuck base.

It is a top view which shows 1st Embodiment of this invention. It is a front view which shows 1st Embodiment of this invention. It is a top view which shows the case where it has been aligned. It is a top view which shows the case where it is not aligned. FIG. 5A is a plan view showing a second embodiment of the present invention, FIG. 5A is a plan view showing a case where alignment is performed, and FIG. 5B is a plan view showing a case where alignment is not performed. It is an enlarged plan view which shows the principal part of 3rd Embodiment of this invention. It is an enlarged plan view which shows the principal part of 4th Embodiment of this invention. It is a flowchart which shows a prior art example.

Explanation of symbols

1 Robot Hand 3 Wafer Chuck 5 Chuck Base 7 Wafer Arm 9 Finger 13 Notch Guide 15 Arm Open / Close Cylinder 20 Wafer Notch

Claims (7)

In a wafer chuck comprising a chuck base provided on a robot hand and a pair of openable and closable wafer arms provided on the chuck base;
A guide member provided between the two wafer arms of the chuck base and contacting a notch of the wafer or an orientation flat;
Means for measuring a holding interval between the two wafer arms;
A wafer chuck aligning confirmation device characterized by comprising: A chuck base provided in the robot hand, a pair of wafer arms provided in the chuck base and arranged symmetrically with respect to the center extension line of the robot hand, and provided in the wafer arm, sandwiching the wafer A wafer chuck comprising: a finger to perform and a driving means for opening and closing the pair of wafer arms;
A guide member provided between the wafer arms of the chuck base and contacting a notch of the wafer or an orientation flat, the guide member being disposed on a central extension line of the robot hand;
Means for measuring a holding interval between the two wafer arms;
A wafer chuck aligning confirmation device characterized by comprising:   3. The wafer chuck aligning confirmation apparatus according to claim 1, wherein the guide member is a notch guide or an orientation flat guide.   3. The wafer chuck aligning confirmation apparatus according to claim 1, wherein the clamping interval is an interval between fingers of both wafer arms or between clamping units. A method for confirming wafer alignment by using the wafer chuck aligning confirmation device according to claim 1 or 2;
A process of moving the robot hand to the design position and causing the opened wafer arm to face the wafer on the wafer holder;
Moving the robot hand in the direction of the center extension line thereof, moving the guide member toward the notch or orientation flat of the wafer, and contacting the guide member with the notch or orientation flat of the wafer; ,
A step of sliding both the wafer arms inward to close the wafer chuck and sandwiching the wafer;
A step of measuring a holding interval between the two wafer arms;
A step of comparing the measured clamping interval with the design clamping interval;
A method for confirming the alignment of a wafer chuck, comprising:   The guide member is a notch guide having a triangular portion at a tip. When the triangular portion of the notch guide abuts a part of the V-shaped notch, the notch guide further advances in the same direction. 6. The wafer chuck aligning confirmation method according to claim 5, wherein the wafer is rotated and fitted into the notch.   The guide member is an orientation flat guide, and when the horizontal portion of the orientation guide is in contact with a part of the orientation flat, the guide is further advanced in the same direction to rotate the wafer. 6. The wafer chuck aligning confirmation method according to claim 5, wherein the orientation flat is brought into surface contact.

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