JP5413529B2 - Wafer positioning apparatus and wafer bonding apparatus having the same - Google Patents

Description

  The present invention relates to a wafer positioning apparatus and a wafer bonding apparatus having the same used in the field of wafer manufacturing.

  One of the effective means for achieving an improvement in the operation speed, functional advancement, and capacity increase of a semiconductor device is a three-dimensional stack of wafers. By laminating a wafer provided with a conductive wire penetrating inside the semiconductor substrate and connecting and thinning the conductive wire, the derailment length of the circuit can be shortened, and the device can be speeded up and heat generation can be reduced. Further, by increasing the number of layers of the wafer stack, the function of the circuit can be improved and the capacity of the memory can be increased.

  To perform three-dimensional stacking of wafers, a bonding electrode is formed on the surface of the wafer after circuit formation, and positioning is performed so that the electrodes of two wafers or an already stacked wafer and the next wafer to be stacked are aligned with each other. Thus, a wafer bonding apparatus for bonding is proposed, and for this positioning, a rotary encoder that detects a rotation angle is used for a rotation drive unit that rotates the wafer (see, for example, Patent Document 1).

JP 2004-317411 A

  A rotary motor used in a conventional wafer positioning apparatus detects an encoder variation using an absolute angle tool that is a reference of the motor alone, and incorporates a numerical value for correcting the variation into a motor driver. For this reason, encoder fluctuations that occur after incorporation of the motor into the wafer positioning device, for example, encoder fluctuations due to stress, encoder fluctuations due to temperature changes, or replacement due to breakage of the rotary motor or driver must be corrected. It was difficult.

In order to solve the above-mentioned problem, the present invention is a wafer bonding apparatus for bonding a laminated wafer having a plurality of laminated wafers and another wafer, and from the outer shape of the uppermost wafer among the laminated wafers, An outer shape detecting means for detecting a predetermined position of the uppermost wafer, a positioning device for positioning the uppermost wafer with respect to a wafer holder based on a detection result of the outer shape detecting means, and the laminated wafer held by the wafer holder A bonding apparatus that bonds the uppermost wafer and the other wafer; and a transport unit that transports the wafer holder holding the laminated wafer from the positioning apparatus to the bonding apparatus. a rotation driving unit that rotates and a rotational position detection means mounted on the rotary drive unit, the mark formed on the wafer A mark position detector for measuring the position, the rotation angle variation of the rotational position detecting means when the wafer is rotated by the rotary drive unit, is derived from the positional change of the mark measured by said mark position detecting means stored as an approximate periodic function that, at the time of wafer alignment, calculates the rotational angle correction amount of the rotational position detecting means from the approximate function, the control means for correcting the rotational angle of the rotational position detecting means based on the rotational angle correction amount And a wafer bonding apparatus characterized by comprising:

  The present invention also provides a wafer bonding apparatus comprising the wafer positioning apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the wafer positioning apparatus which improved the positioning precision of the wafer, and the wafer bonding apparatus which has this can be provided.

It is a schematic block diagram of the wafer bonding apparatus concerning embodiment. 1 is a schematic configuration diagram of a wafer positioning device according to a first embodiment. It is a schematic block diagram of the wafer external shape detection apparatus concerning 1st Embodiment. It is a flow related to linearity detection and approximate function generation of a rotary encoder. An example of a detection result outside a wafer is shown. It is the figure which showed the linearity fluctuation | variation of the rotary encoder in model. An example of a wafer external shape detection result is shown. Table 1 for deriving the Fourier approximation function Explanation Table 2 for Deriving Fourier Approximation Function Explanation Table 3 for Deriving Fourier Approximation Function The schematic block diagram of the wafer external shape detection apparatus concerning 2nd Embodiment. The figure explaining a mark angle.

  Hereinafter, a wafer positioning apparatus according to an embodiment of the present invention and a wafer bonding apparatus having the same will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a wafer bonding apparatus having a wafer positioning apparatus according to an embodiment.

  In FIG. 1, a wafer bonding apparatus 1 according to an embodiment joins a wafer positioning apparatus 50 containing a wafer outer shape detection apparatus 10 to be described later and two positioned wafers via a wafer holder to form a laminated wafer. It comprises a wafer bonding part 90 to be formed.

  The wafer contour detection apparatus 10 detects the contour of the wafer corresponding to the uppermost bonding surface, the notch position of the wafer, or the orientation flat position of the wafer that has been subjected to the previous process and is loaded into the wafer contour detection apparatus 10. .

  Based on the detection result of the wafer contour detection device 10, the notch position or orientation flat position of the wafer is positioned at a predetermined position of a wafer holder described later by a wafer positioning device 50 described later.

  The wafer positioned on the wafer holder by the wafer positioning device 50 and the set of wafer holders are transferred to the wafer bonding unit 90 by the transfer robot 2, and the two wafers are bonded together by the wafer bonding unit 90 via the wafer holder. A wafer 11 (hereinafter referred to simply as a wafer) is formed.

(First embodiment)
Next, the wafer positioning apparatus 50 according to the first embodiment will be described.

  FIG. 2 is a schematic configuration diagram of the wafer positioning apparatus according to the first embodiment. FIG. 3 is a schematic configuration diagram of the wafer outer shape detection apparatus 10 according to the first embodiment.

  2 and 3, a teaching wafer 11 (hereinafter simply referred to as a wafer) is placed on a turntable 13 fixed to the rotation shaft of the rotary motor 12. Further, the rotary motor 12 incorporates a rotary encoder 14 for detecting the rotational position (rotation angle) of the rotary motor 12. In the following description, a case where the teaching wafer 11 is placed on the turntable 13 will be described. However, the wafer outline detecting device 10 is an apparatus used for detecting the outline of a product wafer.

  As shown in FIG. 12, the teaching wafer 11 is a reference wafer having marks 11A and 11B in at least two locations near the outer periphery of the wafer 11. By measuring the positions of the two marks 11A and 11B on the wafer 11, the angle between the line segment connecting the two marks 11A and 11B and the X axis (referred to as the mark angle), that is, the angle variation of the wafer 11 is measured. It measures, detects the angle fluctuation of the rotary encoder 14, and makes the angle correction of the rotary encoder 14 possible.

  As shown in FIGS. 2 and 3, in the wafer contour detection device 10, a transmission type line sensor 112 is disposed in the vicinity of the outer peripheral portion of the rotating wafer 11.

  The transmissive line sensor 112 is a commonly used wafer contour detection sensor that emits line-shaped parallel light from the light emitting unit 112a, senses the transmitted light with the light receiving unit 112b, and determines the position of the boundary between the transmissive unit and the shielding unit. It is a sensor that outputs.

  Further, as shown in FIG. 3, the control device 20 includes various control units (to be described later) for controlling the rotary motor 12, the transmission line sensor 112, and the like and processing each signal.

  The rotary motor 12 has a rotor and a stator (not shown), and the rotor can be rotated by generating torque by electromagnetic force or the like with respect to the stator.

  The rotary encoder 14 is built in the rotary motor 12 and detects the rotation angle according to the rotation angle of the rotary motor 12. Although the angle can be determined by the pulse count, a count reset is performed by an origin sensor (not shown) when the rotary motor 12 is initialized. Conversion from the count value to the motor rotation angle is performed by a data processing unit (CPU) 21. In the present embodiment, the rotary encoder 14 is built-in, but may be externally attached.

  The turntable 13 is attached to the rotor of the rotary motor 12 and has a function of attracting the wafer 11. The sucked wafer 11 rotates with the rotation of the rotary motor 12. In the embodiment, vacuum suction is used, and vacuum introduction to the turntable 13 is performed by relaying a rotary union (not shown) or the like. Note that electrostatic suction or the like can be used instead of vacuum suction.

  The rotation motor driver 23 in the control device 20 is a control driver for driving the rotation motor 12. When a rotation command is transmitted, rotation at the command rotation speed is possible, and when a position command to the target rotation angle is transmitted. Positioning to a predetermined rotation angle is possible. Various parameters such as driving conditions of the rotary motor 12 can be set, and the rotary motor can be driven according to the parameters.

  The measurement data reading unit 25 has a function of reading data in accordance with time synchronization or encoder count synchronization of output voltages of the transmission line sensor 112, the rotary encoder 14, and the like. The read data is transmitted to the data processing unit 21.

  In the case of the wafer contour detection apparatus 10, the data processing unit (CPU) 21 performs processing such as calculation processing and storage of measurement data, commands to each driver, and reading of the driver status. In addition, the state of the inserted wafer is determined and a processing command corresponding to the state is issued.

  The wafer loading robot 51 shown in FIG. 2 is a robot for loading the wafer 11 from a predetermined storage location onto the turntable 13 of the rotary motor 12. The wafer 11 is sucked and held at the tip of the arm 51a and transferred. Further, the arm 51a can be expanded and contracted with a multi-joint structure.

  The rotary motor elevating mechanism 52 is a drive unit that moves the rotary motor 12 up and down in the vertical direction.

  The wafer transfer mechanism (Y axis) 53 is a mechanism for transferring the wafer 11 from the position of the rotary motor 12 to the wafer holder stage 54. The wafer 11 is sucked and held at the tip of the arm 53a and transferred.

  The wafer transfer mechanism unit (Z axis) 55 is a drive unit that moves the wafer 11 up and down in the vertical direction. It has suction pins for holding the wafer 11 by suction.

  The wafer holder 56 is a base material that holds the wafer 11 and has a surface that detachably sucks the wafer 11.

  The wafer holder stage (θ-axis) 54 a has a mechanism that mounts a wafer transfer mechanism (Z-axis) 55 as a drive unit that rotates the wafer holder 56 and holds the wafer holder 56 by suction.

  The wafer holder stage (X-axis) 54b is a drive unit that moves the wafer holder 56 in the X-axis direction, and has a wafer holder stage (θ-axis) 54a mounted thereon.

  The wafer holder stage (Y axis) 54c is a drive unit that moves the wafer holder 56 in the Y axis direction, and has the wafer holder stage (X axis) 54b mounted thereon.

  The wafer holder loading robot 57 is a robot that transports the wafer holder 56 onto the wafer holder stage 54. The wafer holder loading robot 57 may also be used as the wafer loading robot 51.

  In addition, the respective drive controllers of the rotary motor elevating mechanism 52, wafer transfer mechanism (Y axis) 53, and wafer transfer mechanism (Z axis) 55, and the wafer holder stage (θ axis) 54a, (X axis) 54b and a drive system controller (not shown) including a driver controller for each drive mechanism of the (Y-axis) 54c and a control unit (CPU). The driver controller and the data processing unit 21 shown in FIG. 2 communicate to perform the following wafer positioning sequence control.

  The position of the mark 11 </ b> A is detected by the image position detection sensor 60 on the wafer 11 placed on the wafer holder 56. The image position detection sensor 60 is fixed to a fixing unit (not shown). The wafer 11 is moved in the XY plane by the wafer holder stage 54, and the XY coordinates of the mark 11 A are detected by the image position sensor 60 and stored in the data processing unit 21.

  Next, the linearity detection and correction processing of the rotary encoder 14 will be described with reference to the flowchart shown in FIG.

  FIG. 4 is a flow relating to linearity detection and approximate function generation of the rotary encoder 14. Hereinafter, each step will be described.

Step (S1): Initial value setting When loading the wafer 11 on the turntable 13, it is necessary to change the position of the notch of the wafer for measurement. Let M be the number divided by the notch angle pitch (θpitch: hereinafter referred to as θp) when loading one turn (360 degrees) of the turntable 13. The number of measurement M times is defined as a measurement operation for one rotation of the wafer 11, and the number of repetitions of this measurement operation is N. The notch positioning angle (hereinafter referred to as notch target angle: θt) for N repetitions is initially set.

  The notch angle pitch θp may be changed during one turn of the turntable 13, but here is a fixed value for the sake of simplicity. For example, if the notch angle pitch θp is 45 degrees, there are eight types of notch mounting positions: motor origin 0 degree, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, and 315 degrees. The positions of the marks 11A and 11B on the wafer 11 that have been rotationally moved from the notch position to the notch target angle θt are measured by the image position detection sensor 60.

  In the first embodiment, N = 2, θt = −90 degrees when N = 1, and θt = + 90 degrees when N = 2. In the embodiment, the origin of the apparatus is the turntable center, and the motor origin angle is the X axis. The detection position of the transmission line sensor 112 which is a wafer outer shape measurement sensor is on the X axis. The wafer transfer direction from the turntable 13 to the wafer holder stage 54 is taken as the Y axis.

Step (S2): Wafer mounting The wafer 11 is loaded on the turntable 13 of the rotary motor 12 by automatic robot transfer 51 or manual transfer by a person. The wafer 11 has marks 11A and 11B formed at two locations on the wafer having notches.

Step (S3): Initial wafer outer shape measurement and notch positioning Wafer outer shape data is a measurement data reading unit using the output from the transmission line sensor 112 corresponding to the value of the rotary encoder 14 built in the rotary motor 12 as a pair of data. 25. FIG. 5 shows an example of the detection result outside the wafer. Edges and notch positions over one round are detected. The notch position is detected at a rotation angle of about 3.14 rad.

  After measuring the data for one rotation, the data is transferred to the data processing unit 21, the data is recorded, and the notch angle and the eccentricity are calculated from the wafer outline data (see FIG. 5).

Step (S4): Eccentricity correction and notch initial alignment From the eccentricity coordinates of the wafer 11, the rotation motor is controlled so that the wafer eccentricity is directed in the Y direction. Thereafter, the wafer 11 is transferred to the wafer transfer mechanism (Y axis) 53, the wafer transfer mechanism (Y axis) 53 is moved, and the eccentricity in the Y direction is corrected. After the eccentricity correction, the wafer 11 is returned onto the turntable 13 and the notch position is positioned at 0 degree. After the wafer 11 is transferred from the turntable 13 to the wafer transfer mechanism (Y axis) 53 again, the origin of the rotary motor 12 is returned, and the notch position and the encoder origin are set to 0 degrees.

  Note that steps S3 and S4 are processes for reducing the measurement error in measuring the linearity of the rotary encoder 14, and therefore can be omitted when the tolerance of the rotation angle fluctuation of the rotary encoder 14 is large.

Step (S5): Repeated wafer outer shape measurement and notch positioning Wafer outer shape data is stored in the measurement data reading unit 25 as a pair of output data of the transmission line sensor 112 corresponding to the value of the rotary encoder 14 of the rotary motor 12. . When the data for one rotation is measured, the stored data is transferred to the data processing unit 21, the notch angle and the eccentricity are calculated from the wafer outer shape data, and the notch positioning rotation is performed to the notch target angle θt. When N = 1, the notch target angle θt is set to −90 degrees.

Step (S6): Transfer wafer to wafer holder stage (see FIG. 2)
Here, the wafer holder stage 54 is a stage capable of observing the marks 11A and 11B. The rotary motor 12 is lowered by the rotary motor lifting mechanism 52, and the wafer 11 attracted by the turntable 13 is transferred to the arm 53 a of the wafer transfer mechanism (Y axis) 53. Wafer suction on the turntable 13 is stopped after the suction of the wafer 11 to the arm 53a of the wafer transfer mechanism (Y axis) 53 is confirmed, and transfer to the arm 53a of the wafer transfer mechanism (Y axis) 53 is completed. . The rotary motor elevating mechanism 52 moves to the lower retracted position, and the wafer transfer mechanism (Y axis) 53 can be driven to the wafer holder stage 54 side.

  The wafer transfer mechanism (Y axis) 53 is driven in the Y direction to the delivery position with the wafer holder stage 54. After the wafer transfer mechanism (Y axis) 53 stops, the wafer transfer mechanism (Z axis) 55 is driven upward. The suction pins of the wafer transfer mechanism (Z-axis) 55 are turned on. When it is raised to the delivery position, it is finely moved upward until the suction force is generated while monitoring the suction state of the suction pin. When the suction force on the suction pin side exceeds a predetermined threshold value, the suction of the arm 53a on the wafer transfer mechanism (Y axis) 53 side is turned off. The suction pins are further raised to lift the wafer 11 to the upper standby position. Thereafter, the wafer transfer mechanism (Y axis) 53 is retracted.

  The suction pins of the wafer transfer mechanism (Z axis) 55 are lowered while being held in the wafer suction state. The wafer holder 56 is set to the suction-on state, and the suction pins are lowered to the delivery position. When the suction force of the wafer holder 56 exceeds a predetermined threshold, the suction on the suction pin side is turned off. The suction pin is further lowered and the operation ends at the lower standby position. The suction force may be confirmed by confirming the vacuum pressure. Alternatively, time-controlled conveyance that ignores the vacuum pressure confirmation may be used.

  With the above operation sequence, the wafer 11 could be positioned so that the marks 11A and 11B could be observed.

Step (S7): Mark angle calculation Since the positions of the marks 11A and 11B on the wafer 11 with respect to the notch are known in advance, the mark 11A is moved to a position where it can be observed by the image position detection sensor 60 using the wafer holder stage 54. Let The positions of the two marks 11A and 11B are measured by the image position detection sensor 60, and the mark angles shown in FIG. 12 are calculated. The mark angle is used as data for calculating the fluctuation of the rotation component of the wafer 11. Here, as shown in FIG. 12, the mark angle indicates an angle formed by a line segment connecting the center of the mark 11A and the center of the mark 11B with the X axis described above. That is, when the fluctuation of the rotation component is zero, the line connecting the center of the mark 11A and the center of the mark 11B coincides with the Y axis, and the mark angle is 90 degrees.

Step (S8): Reverse wafer transfer and turntable rotation After measurement of the positions of the marks 11A and 11B is completed, the wafer 11 is reversely transferred via the wafer transfer mechanism (Y axis) 53 and returned to the turntable 13. At this time, the wafer 11 is delivered to the turntable 13 with the turntable 13 rotated by the notch angle pitch θp. Then, it returns to step (S5) and performs an external shape measurement routine. Further, the steps (S5 to S8) are repeated a predetermined number of times (in this case, 8 times), and the position data acquisition of the mark 11A at N = 1 (notch target angle θt = −90 degrees) is completed.

  Thereafter, N = 2 is performed, and the steps (S5 to S8) are repeated in the same manner to acquire data of the marks 11A and 11B at the notch target angle θt = + 90 degrees.

  This completes the acquisition of the position data of the marks 11A and 11B while rotating the notch position of the wafer 11 by a predetermined angle. An example of the result calculated from the data thus obtained is shown in the graph of FIG. In FIG. 7, the horizontal axis indicates the notch angle θn, and the vertical axis indicates the angle formed by the measured marks 11A and 11B.

Subsequently, the linearity of the rotary encoder 14 is examined based on the acquired data. FIG. 6 is a diagram schematically showing the linearity fluctuation of the rotary encoder 14. The actual rotation angle θm changes as shown in the figure during one rotation with respect to the ideal rotation angle θi. For this reason, a rotation angle error is generated not a little. The approximate function of the linearity fluctuation is expressed by the following third-order Fourier series expansion.
f (θ) = (a0 / 2) + a1 × cos θ + b1 × sin θ + a2 × cos 2θ
+ B2 × sin 2θ + a3 × cos 3θ + b3 × sin 3θ ------- (1)
The Fourier series is a function used for a general periodic function, and an approximate function can be derived by obtaining the coefficients a1 to a3 and b1 to b3 of the equation (1).

  However, a0 of these coefficients is not necessary to be derived because it is offset in calculation when calculating the correction value.

  In order to obtain the coefficient, the notch angle for one rotation acquired at the notch target angle −90 degrees and the notch target angle +90 degrees and the mark angle data corresponding to the notch angle are required. FIG. 7 is a graph plotting data measured at the notch angle pitch θp = 30 degrees.

(Data acquired in steps S1 to S8)
Next, the measurement data with the notch target angle −90 degrees and the measurement data with the notch target angle +90 degrees shown in FIG. 7 are synthesized. Depending on the position of the image position detection sensor 60 in the apparatus, the angle formed by the mark 11A and the mark 11B is along the Y-axis, and the mark angle fluctuation is 90 degrees (π / 2 (rad)). Now, the calculation process for setting the offset to zero will be described. An example of the calculation flow is shown in Table 1 of FIG. 8, Table 2 of FIG. 9, and Table 3 of FIG.

The data of D1 to D8 at the right end of Table 1 in FIG. 8 is mark angle data for each notch angle of notch target angle −90 degrees and notch target angle +90 degrees. In the figure, (2) is an average value of mark angle data with a notch target angle of −90 degrees, and (3) is an average value of mark angle data with a notch target angle of +90 degrees.
(8) = (6) + (7) (Calculation of composite waveform)
Each data of (6) = target−90 measurement data− (2) value: removal of offset Each data of (7) = target + 90 measurement data− (3) value: removal of offset (5) is the same as that of (4) Unit conversion values from angles (degrees) to (rad) are shown.

  The calculation of the coefficients of the Fourier series expansion approximation formula will be described with reference to Table 2 shown in FIG. 9 using the synthesized waveform data obtained here.

Using (5) and (8) in Table 2, coefficient calculation corresponding to each notch angle is performed as follows.
In Table 2,
(11) Each numerical value (K01 to K08) corresponding to the notch angle (5) of the row is the same as (8).
(12) Each numerical value (KC11 to KC18) corresponding to the notch angle (5) of the row is (8) × cos ((5))
(13) Each numerical value (KC21 to KC28) corresponding to the notch angle (5) of the row is (8) × cos (2 × (5))
(14) Each numerical value (KC31 to KC38) corresponding to the notch angle (5) of the row is (8) × cos (3 × (5))
(15) Each numerical value (KS11 to KS18) corresponding to the notch angle (5) of the row is (8) × sin ((5))
(16) Each numerical value (KS21 to KS28) corresponding to the notch angle (5) of the row is (8) × sin (2 × (5))
(17) Each numerical value (KS31 to KS38) corresponding to the notch angle (5) of the row is (8) × sin (3 × (5))

  The numerical values written as (11) average to (17) average indicate the average value of the values in the above-mentioned (11) to (17) columns corresponding to the respective notch angles. Using the respective average values, the final coefficient of the formula (1) is shown by the calculation formula of Table 3 shown in FIG. In this example, the notch angle pitch θp is 45 degrees. However, if this pitch is reduced, the number of data corresponding to the corresponding notch angle (5) increases and the accuracy of the approximation function increases. A solid line f (θn) in FIG. 7 is an approximate curve based on the Fourier series expansion thus obtained.

  Next, the notch positioning sequence of the wafer 11 will be described below. First, the correction operation will be described. This correction sequence is incorporated in the notch positioning operation of the wafer 11.

The correction angle θh is expressed by the following equation using the approximate function f (θ) of equation (1).
θh = f (θn + θrs) −f (θn)
Here, θn represents the notch position. θrs represents a relative angle from the position of the transmission line sensor 112 to a target angle (a general wafer, not a teaching wafer). The approximate function (1) of the rotary encoder 14 is expressed by the coordinates of the rotary encoder 14.

Assuming that the pulse count for one round of the rotary encoder 14 is Nep, θ = 2 × π × (N / Nep) f (N) = (a0 / 2) + a1 × cos (2 × π × (N / Nep))
+ B1 × sin (2 × π × (N / Nep))
+ A2 × cos (4 × π × (N / Nep))
+ B2 × sin (4 × π × (N / Nep))
+ A3 × cos (6 × π × (N / Nep))
+ B3 × sin (6 × π × (N / Nep)) (18)

Accordingly, assuming that the rotary encoder 14 value Nn corresponding to the notch angle θn and the rotary encoder value Nrs corresponding to the relative angle θrs, θh = f (Nn + Nrs) −f (Nn)
It can be expressed. The unit of θh calculated here is (rad).

  The above correction value is added to the rotation angle to the target when the angle of the wafer is positioned. The angle of movement of the correction value-included target to the target is driven by the rotary motor 12, and the angle determination of the notch position (or orientation flat position) is completed.

  By performing the above measurement and processing, the linearity correction of the rotary encoder 14 can be performed. Thereby, it becomes possible to position the wafer 11 at the time of product bonding with higher accuracy.

  As described above, in the first embodiment, the rotation angle variation of the rotary encoder 14 built in the rotary motor 12 is calculated from the rotation variation of the mark angle formed by the marks 11 </ b> A and 11 </ b> B formed on the wafer 11. It is possible to improve the positioning accuracy of the actual wafer based on the derived approximate function.

(Second Embodiment)
FIG. 11 is a schematic configuration diagram of a wafer outline detecting device of the wafer positioning device according to the second embodiment. In the first embodiment, the marks 11A and 11B on the wafer 11 are detected by the wafer holder stage 54. However, in the second embodiment, an image position detection sensor and a servo mechanism for controlling this in the radial direction of the wafer. Is arranged on the wafer outer shape detection device 10 side, and the marks 11A and 11B can be detected on the turntable 13 of the rotary motor 12. The same configurations and operations as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, the configuration and operation of the wafer bonding apparatus 1 are the same as those in the first embodiment, and a description thereof will be omitted.

  In FIG. 11, in the wafer contour detection device 10, the wafer 11 is placed on a turntable 13 fixed to the rotation shaft of the rotary motor 12. Marks 11A and 11B are formed on the wafer 11 at predetermined positions. The rotary motor 12 has a built-in rotary encoder 14 for detecting the rotational position (rotation angle) of the rotary motor 12.

  Above the wafer 11, an image position detection sensor 15 for detecting the marks 11A and 11B on the wafer 11 and the image position detection sensor 15 are supported, and the image position detection sensor 15 is moved in the radial direction of the wafer 11. A servo mechanism 16 is arranged. The servo mechanism 16 is composed of a linear motor 18 incorporating a linear encoder 17, and moves the image position detection sensor 15 in the radial direction of the wafer 11.

  In addition, the control device 20 includes various control units (to be described later) for controlling the rotary motor 12, the image position detection sensor 15, the linear motor 18, and the like and processing each signal.

  The linear motor 18 is a mechanism that enables the image position detection sensor 15 to be driven in the radial direction of the wafer 11. The linear motor 18 has a movable part and a fixed part that generate an electromagnetic driving force using a three-phase coil and a magnet, and is fixed. The movable part is driven by an electromagnetic driving force with respect to the part. The image position detection sensor 15 is fixed to the movable part. It also has a built-in guide mechanism and has a positioning resolution of several μm.

  Note that the resolution necessary for mark detection of the wafer 11 depends on the number of sampling data, but about 10 μm is required. Therefore, any driving mode having a positioning ability of several μm can be used other than single-phase VCM driving or electromagnetic driving force. A pneumatic actuator or the like having a pneumatic driving force may be used.

  The image position detection sensor controller 17 detects the position of the image position detection sensor 15 and transmits the detection result to the measurement data reading unit 25. The position data is sent from the measurement data reading unit 25 to the data processing unit 21 and used for analysis of the rotation angle variation of the rotary encoder 14.

  The linear motor driver 22 in the control device 20 is a control driver for driving the linear motor 18 and can be positioned at a predetermined position when a position command is transmitted. When the thrust command is transmitted, the mover can be driven with a predetermined thrust. Various parameters such as driving conditions of the linear motor 18 can be set, and linear motor driving according to the parameters is enabled.

  In the wafer outer shape detection apparatus 10 having such a configuration, linearity data acquisition of the rotary encoder 14, generation of an approximate function, and angle correction of the rotary encoder 14 using the approximate function are performed in the steps shown in FIG. Note that each step shown in FIG. 4 is the same as that of the first embodiment except for the process of transporting the wafer to the wafer holder, and a description thereof will be omitted.

  In the present embodiment, compared with the first embodiment, the wafer is transported only by the wafer transport mechanism (Y axis) 53, and the transport operation to the wafer holder stage 54 is not required, so that the mark 11A can be obtained in a short time. , 11B position data acquisition can generate correction data.

  As described above, according to the wafer positioning apparatus according to the embodiment, the linearity fluctuation data of the rotary encoder can be obtained in the state in which the rotary motor is incorporated in the apparatus and the use environment, and the correction is performed based on the result. Positioning accuracy is not impaired. Further, an absolute reference tool or the like is not necessary, and correction can be easily realized. Further, when the rotary motor is broken, the linearity fluctuation data of the rotary encoder can be obtained again after exchanging the motor alone, so that it is not necessary to replace the rotary motor driver.

  As a result, the positioning accuracy in the wafer bonding apparatus is remarkably improved, and it is possible to prevent a decrease in the yield of the semiconductor manufacturing process due to a positioning failure when bonding two wafers.

  The above-described embodiment is merely an example, and is not limited to the above-described configuration and shape, and can be appropriately modified and changed within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Wafer bonding apparatus 2 Transfer robot 10 Wafer external shape detection apparatus 11 Teaching wafer (wafer)
DESCRIPTION OF SYMBOLS 12 Rotation motor 13 Turntable 14 Rotary encoder 15 Image position detection sensor 16 Servo mechanism 17 Image position detection sensor controller 18 Linear motor 20 Control apparatus 21 Data processing part (CPU)
DESCRIPTION OF SYMBOLS 22 Linear motor driver 23 Rotation motor driver 25 Measurement data reading part 50 Wafer positioning device 51 Wafer insertion robot 52 Rotation motor raising / lowering mechanism part 53 Wafer conveyance mechanism part (Y axis)
54 Wafer holder stage 55 Wafer transfer mechanism (Z axis)
56 Wafer Holder 57 Wafer Holder Loading Robot 90 Wafer Bonding Unit 112 Transmission Line Sensor

Claims (8)

A wafer bonding apparatus for bonding a laminated wafer having a plurality of laminated wafers and another wafer,
Outer shape detecting means for detecting a predetermined position of the uppermost wafer from the outer shape of the uppermost wafer of the laminated wafers
A positioning device for positioning the uppermost wafer with respect to a wafer holder based on the detection result of the outer shape detection means;
A bonding apparatus for bonding the top wafer and the other wafer of the laminated wafer held by the wafer holder;
Transport means for transporting the wafer holder holding the laminated wafer from the positioning device to the bonding device;
The positioning device includes a rotation driving unit that rotates the wafer,
A rotational position detecting means mounted on the rotary drive unit,
Mark position detecting means for measuring the position of the mark formed on the wafer;
Rotational angle variation of the rotational position detecting means when the wafer is rotated by the rotational drive unit is stored as an approximate periodic function derived from the position variation of the mark measured by the mark position detecting means , and wafer alignment And a control unit that calculates a rotation angle correction amount of the rotation position detection unit from the approximate function and corrects a rotation angle of the rotation position detection unit based on the rotation angle correction amount. Wafer bonding equipment. The wafer bonding apparatus according to claim 1, wherein the predetermined position of the wafer includes a notch position formed in the wafer. The wafer bonding apparatus according to claim 1, wherein the predetermined position of the wafer includes an orientation flat position formed on the wafer. The wafer bonding apparatus according to claim 1, wherein the outer shape detection unit includes a transmission line sensor. The control means detects the position of the mark by the mark position detection means after the predetermined position of the wafer is rotated from the initial angle position to the predetermined rotation angle position by the rotation driving unit.
5. The wafer bonding apparatus according to claim 1, wherein the predetermined rotation angle position is controlled by a relative angle from a reference angle position of the outer shape detection unit. 6. The detection of the mark position by the mark position detection means is performed in a state where the wafer is held by the wafer holder or a state where the wafer is held by the rotation driving unit. The wafer bonding apparatus according to item. The wafer bonding apparatus according to claim 5 or 6, wherein a relative angle from the reference angle position is approximately 90 degrees and approximately -90 degrees. The wafer bonding apparatus according to claim 1, wherein the rotational position detection unit includes a rotary encoder.

Images