JP2013191890A - Positioning device and positioning method, and semiconductor manufacturing device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positioning device and a positioning method that prevent positioning precision from deteriorating by detecting a position shift amount of a detection device and correcting positioning amounts of a wafer and a wafer holder, and a semiconductor manufacturing device with the same.SOLUTION: There are provided: a positioning device 50 that includes a holder stage 6 capable of holding a wafer 1 positioned at a wafer holder 2 and moving in XYθ directions, a detection device 8 which detects respective reference marks of the wafer and wafer holder, and a control section 9 measuring variation amounts of position coordinates of the detection device and holder stage on the basis of results of detection of position coordinates of a reference point 7b formed at the holder stage by the detection device, the control section correcting positioning amounts of the wafer and wafer holder through the holder stage on the basis of the measured variation amounts of the position coordinates; and a semiconductor manufacturing device 100 having the same.

Description

  The present invention relates to a wafer positioning apparatus, a positioning method, and a semiconductor manufacturing apparatus having these in a wafer stacking process.

  In recent years, portable electronic devices such as mobile phones, notebook computers, portable audio devices, and digital cameras have made remarkable progress. Along with this, in addition to improving the performance of the chip itself as well as the performance of the chip itself, improvements in the chip mounting technology are also sought. There is a need for improved packaging technology.

  In order to reduce the chip mounting area, stacking chips is used to increase the amount of mounted chips without increasing the mounting area, thereby reducing the effective mounting area. For example, a chip-to-chip or wire-bonding system that connects the chip and the mounting board with a wire, or a flip-chip system that connects the chip to the chip or the chip and the mounting board via a micro bump provided on the back surface of the chip Or a chip-to-chip or a chip-to-mounting board connected by using both a wire bond method and a flip-chip method.

  In addition, when a heat treatment or a pressure treatment is involved in an electrode bonding process between wafers, the process is generally performed in a state where the wafer is attracted to a wafer holder. In the case of using a wafer holder, it is disclosed that two sets of wafer holders in a state in which wafers are attracted are prepared, a highly accurate positioning process is performed in a wafer bonding apparatus, and a bonding process is performed while facing each other. (For example, refer to Patent Document 1).

JP 2005-302858 A

  Conventionally, a pre-alignment apparatus (positioning apparatus) is used as an apparatus for positioning a wafer with respect to a wafer holder. This positioning device detects the respective reference marks formed on the wafer and the wafer holder by a detection device supported above the wafer holder stage, and moves the wafer through the holder stage based on the detection result to the wafer holder. Position.

  However, since the detection device for detecting the reference mark is disposed via a support member disposed above the holder stage with a gap, it is caused by thermal expansion of the support member accompanying a change in the ambient temperature of the positioning device. There is a problem in that the positioning accuracy of the wafer and the wafer holder is deteriorated because of deviation from a predetermined position.

  The present invention has been made in view of the above problems, a positioning device that detects a positional deviation amount of a detection device and corrects a positioning amount of a wafer and a wafer holder, and prevents deterioration of positioning accuracy, and a positioning method. Another object is to provide a semiconductor manufacturing apparatus having these.

  In order to solve the above problems, the present invention provides a holder stage that holds a wafer positioned in a wafer holder and is movable in the XYθ direction, a detection device that detects respective reference marks of the wafer and the wafer holder, and the holder Based on the result of detecting the position coordinates of the reference point formed on the stage by the detection device, the control unit that measures the amount of change in the position coordinates of the detection device and the holder stage, the control unit, Provided is a positioning apparatus that corrects a positioning amount between the wafer and the wafer holder through the holder stage based on the measured change amount of the position coordinates.

  The present invention also provides a detection device for holding a wafer positioned on a wafer holder and detecting the position coordinates of a reference point disposed on a holder stage movable in the XYθ directions for the respective reference marks of the wafer and the wafer holder. The amount of change in the position coordinates between the detection device and the holder stage is measured based on the result detected in step, and the amount of positioning between the wafer and the wafer holder is determined based on the amount of change in the measured position coordinates. The positioning method is characterized in that correction is performed via

  The present invention also provides a semiconductor manufacturing method comprising the positioning device and the positioning method.

  According to the present invention, there are provided a positioning apparatus, a positioning method, and a semiconductor manufacturing apparatus having these, which detect a positional deviation amount of a detection apparatus and correct a positioning amount of a wafer and a wafer holder to prevent deterioration of positioning accuracy. be able to. In particular, it has a great effect when the apparatus is not arranged in the temperature control chamber and the temperature change around the apparatus is large.

1 is a schematic configuration diagram of a semiconductor manufacturing apparatus including a positioning apparatus according to an embodiment and a wafer bonding apparatus having the positioning apparatus. It is a side view of a positioning device. It is a schematic block diagram of a positioning device. It is a harm figure which shows the amount of misalignment measurement state of the detecting device in a positioning device. The schematic control flow of a positioning apparatus is shown, (a) shows the whole flow, (b) shows the deviation amount measurement flow of the detection apparatus (camera), and (c) shows the positioning correction flow of the wafer and the wafer holder.

  Hereinafter, a positioning device and a semiconductor manufacturing apparatus having the same according to an embodiment of the present invention will be described.

  FIG. 1 is a schematic configuration diagram of a semiconductor manufacturing apparatus including a positioning apparatus according to an embodiment and a wafer bonding apparatus having the positioning apparatus. FIG. 2 is a schematic side view of the positioning device. FIG. 3 is a schematic configuration diagram of the positioning device. FIG. 4 is a schematic diagram illustrating a state of measuring a displacement amount of the detection device in the positioning device. FIG. 5 shows a schematic control flow of the positioning apparatus. (A) is an overall flow, (b) is a detection amount (camera) shift amount measurement flow, and (c) is a wafer and wafer holder positioning correction flow. Each is shown. In FIG. 3, the XYZ axes are defined as shown.

  Referring to FIG. 1, a semiconductor manufacturing apparatus 100 according to an embodiment includes a positioning device 50 having a built-in wafer outer shape detection device 10 and wafer bonding for bonding two positioned wafers via a wafer holder to form a laminated wafer. And a mating unit 90.

  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 the wafer holder by a positioning device 50 described later.

  A set (workpiece) of the wafer and the wafer holder positioned on the wafer holder by the wafer positioning device 50 is transferred to the wafer bonding unit 90 by the transfer robot 60, and the two wafers are joined by the wafer bonding unit 90 via the wafer holder. Thus, the bonded wafer 1 is formed.

  In FIG. 2, in the wafer positioning device 50, an image pickup unit 8 supported by a support unit 51 is disposed above the wafer stage 6, as will be described later.

  Hereinafter, the positioning device 50 will be described with reference to FIG.

  In FIG. 3, a wafer 1 (both a single wafer and a bonded wafer are referred to as a wafer) is placed on a turntable fixed to the rotating shaft of the wafer rotating table 3. The motor 3a of the wafer turntable 3 has a built-in rotary encoder 3b for detecting the rotation position (rotation angle) of the motor 3a.

  The wafer 1 has alignment marks 1a and 1b and a notch n in at least two locations near the outer periphery of the wafer 1. By measuring the positions of the two alignment marks 1a and 1b on the wafer 1, the angle between the line segment connecting the two marks 1a and 1b and the X axis, that is, the angle variation of the wafer 1 is measured.

  In the wafer contour detection device 10, a transmission line sensor 4 is disposed in the vicinity of the outer peripheral portion of the rotating wafer 1 and detects the position of the notch n.

  The transmissive line sensor 4 is a commonly used wafer contour detection sensor that emits line-shaped parallel light from a light emitting unit, senses the transmitted light with a light receiving unit, and outputs the position of the boundary between the transmissive unit and the shielding unit. It is a sensor.

  In addition to controlling the wafer turntable 3, the transmission line sensor 4, and the like, it has a controller 9 composed of various control units to be described later for processing each signal.

  The motor 3a of the wafer turntable 3 has a rotor and a stator (not shown), and the rotor can rotate by generating torque by electromagnetic force or the like with respect to the stator.

  The rotary encoder 3b is built in the motor 3a and detects the rotation angle according to the rotation angle of the motor 3a. Although the angle can be determined by the pulse count, the count is reset by an origin sensor (not shown) when the motor 3a is initialized. Conversion from the count value to the motor rotation angle is performed by the data processing unit (controller 9). The rotary encoder 3b may be internal or external.

  The wafer turntable 3 is attached to the rotor of the motor 3a and has a function of sucking the wafer 1. The sucked wafer 1 rotates with the rotation of the wafer turntable 3. In the embodiment, vacuum suction is used, and vacuum introduction up to the wafer turntable 3 is performed via a rotary union or the like. Note that electrostatic suction or the like can be used instead of vacuum suction.

  The motor driver in the controller 9 is a control driver for driving the wafer rotation table 3. 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, a predetermined rotation is performed. Positioning to the corner becomes possible. Various parameters such as the driving conditions of the wafer turntable 3 can be set, and the wafer turntable 3 can be driven according to the parameters.

  The controller 9 has a function of reading data in accordance with time synchronization or encoder count synchronization of output voltages of the transmission line sensor 4 and the rotary encoder 3b. The read data is processed.

  Further, in the case of the wafer contour detection apparatus 10, the controller 9 performs processing such as calculation processing and storage of measurement data, instructions 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.

  A wafer loading robot 11 shown in FIG. 3 is a robot for loading the wafer 1 onto the wafer turntable 3 from a predetermined storage location. The wafer 1 is sucked and held at the tip of the arm and transferred. Further, the arm can be expanded and contracted with a multi-joint structure.

  The wafer turntable lifting mechanism 3c is a drive unit that moves the wafer turntable 3 up and down in the vertical direction.

  The transfer mechanism unit (Y axis) 5 is a mechanism unit for transferring the wafer 1 from the wafer rotary table 3 to the wafer holder stage 6. The wafer 1 is sucked and held at the tip of the arm and transferred.

  The wafer transfer unit (Z-axis) 6a is a drive unit that moves the wafer 1 up and down in the vertical direction. It has suction pins for holding the wafer 1 by suction.

  The wafer holder 2 is a base material that holds the wafer 1 and has a surface that detachably sucks the wafer 1.

  The wafer holder stage (θ-axis) 6 b has a mechanism for mounting the wafer transfer unit (Z-axis) 6 a as a drive unit for rotating the wafer holder 2 and holding the wafer holder 2 by suction.

  Wafer holder stage (X axis) 6c is mounted with a wafer holder stage (θ axis) 6b as a drive unit that moves wafer holder 2 in the X axis direction.

  Wafer holder stage (Y-axis) 6d is a drive unit that moves wafer holder 2 in the Y-axis direction, and has wafer holder stage (X-axis) 6c mounted thereon.

  The wafer holder loading robot 12 is a robot that transports the wafer holder 2 onto the wafer holder stage 6. The wafer holder loading robot 12 may also be used as the wafer loading robot 11.

  Further, the controller 9 includes a driver controller for each of the drive mechanisms of the rotary motor elevating mechanism 3c, the wafer transfer unit (Y axis) 6d, and the wafer transfer unit (Z axis) 6a, and a wafer holder stage (θ axis) 6b, (X A wafer positioning sequence control is performed including a driver controller and a control unit (CPU) for each of the drive mechanisms of the (axis) 6c and (Y-axis) 6d.

  The wafer 1 placed on the wafer holder 2 detects the positions of the alignment marks 1 a and 1 b by the image pickup unit 8. The image capturing unit 8 is fixed to a fixing unit (not shown). The wafer 1 is moved in the XY plane by the wafer holder stage 6, and the XY coordinates of the alignment marks 1 a and 1 b are detected by the image capturing unit 8.

  In the positioning device 50 according to the embodiment, as shown in FIG. 2, the image capturing unit 8 is supported by the tip of the support member 51 and is installed above the holder stage 6. Since the ambient temperature of the positioning device 50 is placed in an environment such as a clean room, a predetermined temperature control is performed. However, since the support member 51 is in the shape of a bar that is long in one axis direction, image capturing can be performed with a slight temperature change. Deviation occurs in the position of the portion 8, and as a result, deviation occurs in the positioning of the reference marks of the wafer 1 and the wafer holder 2.

  In the positioning device 50 according to the embodiment, the positional deviation of the image pickup unit 8 is calculated by measuring the reference point coordinates of the holder stage 6 and is used as correction data when positioning the wafer 1 and the wafer holder 2. The accuracy is improved.

  Hereinafter, description will be given with reference to the control flow shown in FIG. 4 and FIG.

  In FIG. 5A, as a control flow, the shift amount of the image pickup unit (also referred to as a camera) 8 is measured in step 1, and this shift amount is used as a correction amount. In step 2, the reference marks 1a and 1b on the wafer 1 are measured. The wafer holder 2 reference marks 2a and 2b are detected, and the wafer 1 and the wafer holder 2 are positioned. Note that the measurement of the deviation amount is performed by selecting any one of the initial time point, a predetermined time interval, or every positioning.

  FIG. 5B shows a flow of measuring the deviation amount of the image capturing unit 8. Here, a case where the deviation amount measurement is performed for each positioning will be described, but it is needless to say that the present invention is not limited to this.

Step S11
The wafer holder stage (X axis) 6c and (Y axis) 6d are driven so that the reference lift pin (PUP) 7b in FIG.

Step S12
The wafer transfer unit (Z-axis) 6a is driven up and down to focus the tip of the reference lift pin 7b on the image pickup unit 8.

Step S13
The position of the reference lift pin 7b is detected by processing the image obtained from the image capturing unit 8.

Step S14
Based on the coordinates of the reference lift pin 7b obtained in step S13, the deviation amount (ΔX, ΔY) of the reference lift pin 7b is calculated by the controller 9 and stored in the memory of the controller 9.

  With the above steps, the measurement of the deviation of the image pickup unit (camera) 8 is completed.

  Next, positioning correction of the wafer (WH) 1 and the wafer holder 2 is performed based on FIG.

Step S21
The holder stage 6 is XY-driven so that the reference mark of the wafer (WH) 1 or the wafer holder 2 comes to the center of the visual field of the image pickup unit 8.

Step S22
The reference mark position of the wafer 1 or the wafer holder 2 is detected by image processing.

Step S23
The controller 9 calculates deviation amounts X1 and Y1 between the detected reference mark position coordinates and the design value.

Step S24
The deviation amount is calculated and stored using the coordinate correction amount (X0, Y0) = (X1−ΔX, Y1−ΔY). This correction amount is used when the coordinates of the wafer 1 or the wafer holder 2 are detected, the shift amount of the image pickup unit 8 is corrected, and the alignment of the reference marks of the wafer 1 and the wafer holder 2 is performed.

  In the above description, the lift pin 7b is used as the reference lift pin, but other lift pins 7a and 7c may be used.

  Hereinafter, the positioning process of the positioning device 50 will be described. For the coordinate value, the above correction amount is applied to correct the deviation of the image capturing unit 8.

  The wafer 1 loaded from the outside by the positioning device 50 is subjected to contour detection processing in the wafer rotation table 3 constituting the wafer contour detection device 10 and the contour detection unit 4 provided in the vicinity of the wafer rotation table 3. Thereafter, the wafer is transferred onto the wafer holder 2 held on the holder stage 6 via the transfer mechanism 5 with high accuracy.

  The wafer 1 carried into the positioning device 50 by the wafer loader unit 11 is transferred onto the wafer turntable 3. The wafer turntable 3 holds the back surface of the wafer 1 by vacuum suction.

  On the other hand, the wafer holder 2 carried into the apparatus by the holder loader unit 12 is vacuum-sucked and held on the holder stage 6. When the reference marks 2a and 2b for positioning the holder are present on the carried wafer holder 2, the holder stage 6 is driven so that the reference marks 2a and 2b are directly below the image pickup unit 8. Drive to detect images of the respective reference marks 2a and 2b. Here, coordinate correction amounts (X0, Y0) are used.

  The controller unit 9 takes displacement data of at least one rotation while rotating the wafer turntable 3 from the outer shape detection unit 4 and analyzes the data, whereby the amount of deviation in the XY direction (Xw, Yw) and notch position angle (θw) are detected. Since a known method is used for this detection algorithm, description thereof is omitted.

  The controller unit 9 calculates the eccentricity amount of the wafer holder 2 relative to the holder stage 8 relative to the holder stage coordinate center and the deviation amount of the rotation component from the detection coordinates 2a and 2b.

  When the positional deviation amount of the wafer 1 and the positional deviation amount of the wafer holder 2 are obtained, the operation of transferring the wafer 1 to the wafer holder 2 is performed next. The coordinate correction amounts (X0, Y0) are also used in the subsequent processing.

  First, in order to align the notch n position of the wafer 1 with the 0 degree position (apparatus X coordinate), the wafer rotation table 3 is rotated by −θw. At this time, since the center position of the wafer 1 is also rotated by −θw, the shift amount in the XY directions after the notch n position is adjusted to 0 degree is calculated.

  Next, in order to pass the wafer 1 held on the wafer rotation table 3 to the transfer unit 5, the wafer rotation table 3 is lowered to the position of the transfer mechanism unit 5, and the transfer mechanism unit 5 performs wafer suction at that position. After confirming the predetermined suction pressure, the vacuum suction of the wafer turntable 3 is turned off. Thereafter, the wafer turntable 3 is lowered to a retracted position (a position that does not interfere with conveyance).

  The wafer 1 delivered to the transport mechanism unit 5 is transported to a position directly above the holder stage 6 by driving the transport mechanism unit 5 to a predetermined feeding position in the Y direction.

  In order to transfer the wafer 1 transported to the position just above the holder stage 6 to the wafer holder 2, the controller 9 instructs the holder stage 6 to move to the receiving position.

  After the holder stage 6 is moved to the target position, the controller 9 raises the lift pins 7a to 7c attached to the holder stage 6 to a position where the lift pins 7a to 7c come into contact with the back surface of the wafer 1 held by the transfer mechanism unit 5, and the lift pins 7a to 7c. The wafer 1 is held with the vacuum suction by 7c turned ON.

  After confirming that the wafer 1 is securely held by the lift pins 7a to 7c, the controller 9 turns off the wafer suction of the transfer mechanism unit 5, further raises the lift pins 7a to 7c, and the transfer mechanism unit 5 is driven. Wait at a possible retreat position.

  After confirming that the lift pins 7 a to 7 c have moved to the standby position, the controller 9 drives the transfer mechanism 5 to the retracted position, and then the lift pins 7 a to 7 c holding the wafer 1 are held on the holder stage 6. The wafer holder 2 is lowered to a position where the suction surface of the wafer holder 2 comes into contact with the wafer.

  Next, the controller 9 applies an electrostatic holding voltage to the wafer holder 2 to electrostatically attract the wafer 1 to the wafer holder 2. After applying the holding voltage and waiting for a predetermined time and confirming that the wafer 1 has been sucked with an appropriate holding force, the vacuum suction of the lift pins 7a to 7c is turned off, and further lowered, and stopped at the retracted position.

  At this time, the wafer 1 has been transferred to the wafer holder 2, but the eccentricity of the wafer 1 and the amount of positional deviation of the wafer holder 2 that occurred on the wafer turntable 3 at the time of transfer can be obtained by a single movement process. The greatest feature is that it is corrected.

  At the time of the first transfer process, the center of the outer shape of the wafer 1 coincides with the center of the wafer holder 2, and the notch n position is also positioned at the 0 degree position.

  Next, it is inspected whether the alignment marks 1a and 1b formed on the wafer 1 are within a predetermined range. Since the positions where the alignment marks 1a and 1b exist on the wafer 1 differ depending on the wafer 1, the operator registers them with apparatus constants or recipes before starting the processing.

  The controller 9 detects the images of the alignment marks 1 a and 1 b by driving the holder stage 6 so that the alignment mark formed on the wafer 1 is directly below the image capturing unit 8. When at least two alignment marks 1a and 1b are detected, the controller unit 9 calculates a wafer coordinate shift amount and a rotation component shift amount with respect to the holder stage coordinate center from the detected coordinates.

  Next, the controller 9 confirms whether the amount of deviation of the wafer coordinates with respect to the wafer holder coordinates is within a specified range. If the amount of deviation of the wafer coordinates is within a specified range, it is determined that the wafer transfer is completed, and the wafer holder 2 is conveyed to a subsequent process apparatus (such as a bonding apparatus) while the wafer 1 is adsorbed.

  If the deviation amount of the wafer coordinates exceeds the specified range, correction is performed according to the following procedure.

  First, the holder stage 6 is moved again to the position where the wafer is received at the time of the first transfer. After the movement is completed, the lift pins 7a to 7c are driven upward, temporarily stopped at a position where they contact the back surface of the wafer 1, and the vacuum suction of the wafer by the lift pins 7a to 7c is turned on.

  Next, the electrostatic chucking voltage applied to the wafer holder 2 is turned off, and after the holding force is sufficiently reduced, the lift pins 7a to 7c are raised to stop the wafer 1 at the upper standby position.

  Next, the transport mechanism unit 5 that has been moved to the retreat position is moved to the feed position, and is placed on standby under the wafer 1. Next, the lift pins 7a to 7c are lowered to the wafer delivery position with the transfer mechanism unit 5, the wafer 1 is vacuum-sucked to the transfer mechanism unit 5, and then the vacuum suction of the lift pins 7a to 7c is turned off and the lowermost part is retracted. Lower to position.

  Next, the holder stage 6 is corrected and driven. In the correction drive, first, the θ rotation axis, and then the X axis and the Y axis are corrected and driven.

  When the correction driving of each axis of the holder stage 6 is completed, the wafer 1 temporarily retracted on the transport mechanism unit 5 is lowered as it is in the same procedure as the first transfer process, and is held and attracted to the wafer holder 2. Since the wafer coordinate deviation amount can be set within a specified range by this processing, the wafer holder 2 is transported to a subsequent process apparatus (such as a bonding apparatus) while the wafer 1 is adsorbed. This completes the wafer transfer process.

  As described above, according to the positioning device according to the embodiment, it is possible to correct the coordinate deviation by detecting in advance the positional deviation of the image pickup unit (camera) 8 due to a temperature change around the apparatus. it can. Further, since the deviation correction is possible, the positioning accuracy of the wafer and the wafer holder can be improved. As a result, it is possible to reduce the bonding failure of the semiconductor device.

  Further, since one of the lift pins can be used for camera displacement measurement, there is no need to newly provide a reference position, and the camera can be configured at low cost.

  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 1a, 1b Alignment mark 2 Wafer holder 2a, 2b Reference mark 3 Wafer rotation table 4 External shape detection part 5 Conveyance mechanism part 6 Holder stage 7a, 7b, 7c Lift pin 8 Image pick-up part 9 Controller part 10 Wafer external shape detection apparatus 11 Wafer loader Part 12 Holder loader part 50 Positioning device 51 Supporting part 60 Transfer robot 90 Wafer needle alignment apparatus 100 Semiconductor manufacturing apparatus

Claims (1)

A holder stage that holds the wafer positioned in the wafer holder and is movable in the XYθ direction;
A detection device for detecting the respective reference marks of the wafer and the wafer holder;
Based on the result of detecting the position coordinates of the reference point formed on the holder stage by the detection device, a control unit that measures the amount of change in the position coordinates of the detection device and the holder stage,
The controller is configured to correct a positioning amount between the wafer and the wafer holder via the holder stage based on the measured change amount of the position coordinates.

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