JP5074313B2 - Board inspection equipment - Google Patents

Description

  The present invention relates to a substrate inspection apparatus provided with a stage capable of moving a substrate.

  2. Description of the Related Art Conventionally, there is known a substrate inspection apparatus that performs a macro inspection by transferring a substrate taken out from a storage cassette to a mounting table for macro inspection by a transfer device, and then transferring the substrate to a stage for micro inspection. (For example, refer to Patent Document 1). The stage for micro-inspection is an XYθ stage capable of carrying in the XY directions along the substrate surface and rotating around the normal line of the substrate.

  In addition, a rotation motor for rotating the substrate and a sensor for detecting the outer peripheral edge of the substrate are provided on such a micro inspection stage, and the notch and the orientation flat of the substrate are detected by this sensor, and the rotation angle is aligned by the rotation motor. There is known a method of performing (see, for example, Patent Document 2).

Next, consider a case where the movement in the X and Y directions is performed electrically, and the rotation operation around the normal line of the substrate is performed manually without a rotation motor. In micro-inspection, a plurality of chips on a substrate are sampled and inspected. In many cases, a chip that is specified in advance has a position that is symmetrical with respect to the center line. When the tip is specified symmetrically with respect to the line connecting the two, if the rotation angle is misaligned, the observation position may be misaligned in the vertical direction due to the right / left operation. Therefore, in order to adjust the deviation of the rotation angle, a method of aligning the rotation angle by providing a rod-like knob protruding on the stage and manually operating the knob while looking through the microscope can be considered.
JP 2005-268530 A JP-A-10-70173

However, in the method of providing a rotation motor for rotating the substrate and a sensor for detecting the outer peripheral edge of the substrate, the rotation motor and its control device must be installed on the stage for micro inspection, which greatly increases the apparatus cost.
In addition, in the method of manually rotating the substrate around the normal line, in recent years, the defect of the substrate due to the adhesion of dust has become a problem, and an apparatus that isolates the substrate transfer unit from the inspector is required.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate inspection apparatus capable of performing alignment of the rotation angle of a substrate at a low cost while isolating a substrate transport unit from an inspector. .

In order to solve the above problems, the present invention employs the following means.
The present invention provides a rotary mounting table for mounting a substrate and rotatably supporting the substrate around a normal line, a stage unit for supporting the rotary mounting table and moving in a plane parallel to the substrate, An operation unit for moving the stage unit, a lever unit fixed to the rotary mounting table and extending in the radial direction of the substrate, an observation unit for observing the surface of the substrate on the rotary mounting table, and the stage unit A substrate inspection apparatus including a contact portion that is fixed with respect to the observation portion and extends in a normal direction of the substrate within an operation range of the lever portion is employed.

  According to the present invention, the stage unit is operated by the operation unit to move the rotary mounting table, and the lever unit fixed to the rotary mounting table is abutted against the abutting unit fixed to the observation unit, thereby A rotational force around the normal line of the substrate can be applied to the transfer table, and the substrate that is rotatably supported can be rotated. As a result, the substrate can be rotated without the need for a rotating motor or the like for rotating the substrate, and the surface of the substrate can be observed by the observation unit at an angle that is easy for the operator to observe.

In the above invention, the rotation angle of the substrate may be calculated based on the pattern of the substrate surface observed by the observation unit, and the stage unit may be moved based on the rotation angle.
By calculating the rotation angle of the substrate from the pattern on the surface of the substrate, and rotating the substrate by moving the stage unit based on this rotation angle, the substrate can be easily set at an angle that is easy for an operator to observe.

In the above invention, a sensor that is fixed with respect to the rotation direction of the substrate and that detects the rotation angle of the substrate may be provided, and the stage unit may be moved based on the rotation angle detected by the sensor.
For example, a specific shape such as a notch or an orientation flat provided at a predetermined position of the substrate is detected by a sensor fixed with respect to the rotation direction of the substrate, and the rotation angle of the substrate is calculated. Based on this rotation angle, the stage is calculated. By moving the part and rotating the substrate, it is possible to easily set the substrate at an angle at which the operator can easily observe the substrate.

  According to the present invention, it is possible to perform the alignment of the rotation angle of the substrate at a low cost while isolating the transport portion of the substrate from the inspector.

[First Embodiment]
A substrate inspection apparatus according to a first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the substrate inspection apparatus 1 includes a cassette 10 for storing wafers (substrates) 7, a transfer robot (not shown) that takes out the wafers 7 from the cassette 10 and places them in the macro inspection apparatus 11. A rotary transfer device (not shown) that moves to perform a micro inspection from the macro inspection position, and a wafer mounting table (rotary mounting table) 5 on which the wafer 7 that has been rotated and transferred is rotatably mounted about the rotation axis 9. A stage 40 that supports the wafer mounting table 5 so as to be movable in a uniaxial direction that is parallel to the surface of the wafer 7 and that is in the left-right direction of the inspector; A stage 4 that moves in the direction, a base 16 that supports the stage 4, a microscope (observation unit) 3 that is fixed to the base 16 and observes the surface of the wafer 7, and a wafer that is fixed to the wafer mounting table 5. A knob (lever part) 6 extending substantially in the radial direction of the c, a pin (abutting part) 8 fixed to the microscope 3 and extending in the normal direction of the wafer 7, and a joystick (operating the operation of the stage 4) (Operation unit) 2.

  The wafer mounting table 5 does not have a rotating mechanism such as a motor, and is normally fixed by frictional resistance or the like, and rotates when a force is applied to the knob 6 in the tangential direction of the outer circumference of the wafer 7. Yes.

The stage 4 and the stage 40 are configured to move the wafer 7 placed thereon with respect to the base 16. Specifically, as shown in FIG. 4, the stage 4 includes a guide rail 41, a moving mechanism using a motor and a ball screw (not shown), and the stage 40 is moved along the guide rail 41 with the arrow X with respect to the stage 4. The stage moves in the direction shown. The base 16 includes guide rails 51 and 52 and a moving mechanism using a motor and a ball screw (not shown), and the stage 4 moves along the guide rails 51 and 52 in the direction indicated by the arrow Y with respect to the base 16. It has become.
That is, the stage 40 and the stage 4 constitute an electric XY stage (stage part). The electric XY stage can be automatically moved to a preset coordinate position by a control unit such as a PC (not shown). Further, the coordinate position of the center of the observation image of the current microscope 3 can be detected by the rotational speed of the motor with the position of the rotation shaft 9 as the origin, and is stored in the storage unit of the control unit.

The pin 8 is fixed with respect to the microscope 3, and the knob 6 moves within a predetermined range that can contact the pin 8 by moving the stage 4 and the stage 40.
The joystick 2 is an operating device for an electric XY stage. The joystick 2 can move the stage 4 in the Y direction with respect to the base 16 and can move the wafer mounting table 5 (stage 40) in the X direction with respect to the stage 4. It is like that. Hereinafter, since the wafer mounting table 5 and the stage 40 moving in the X-axis direction can be regarded as one body, the wafer mounting table 5 will be described as a representative.

The operation of the substrate inspection apparatus 1 having the above configuration will be described below with reference to the flowchart shown in FIG.
First, as an initial operation, the stage 4 is operated to move the wafer mounting table 5 to the receiving position (initial position) of the wafer 7 (S0). At this time, for example, by applying a pin (not shown) fixed to the wafer mounting table 5 to a V groove (not shown) fixed to the base 16, the rotation angle of the wafer mounting table 5 is in the initial direction, that is, A predetermined angle with respect to the base 16 (for example, a direction along an arrow X in FIG. 4) is set.

The wafer 7 transferred by the rotary transfer device is mounted on the wafer mounting table 5 on the stage 4 (S1). Here, since the wafer mounting table 5 has mounting parts 17 and 18 shaped to be dropped along the outer peripheral portion of the wafer 7, the center of the wafer 7 and the rotation shaft 9 of the wafer mounting table 5 are one. I'm doing it. If there is a deviation in the rotational direction, it is necessary to detect the deviation and align it.
The stage 4 is a button on an operation panel (not shown) so that the alignment point A on the wafer 7 set in advance is the center position of the image observed by the microscope 3, that is, the optical axis position of the objective lens of the microscope 3. By the operation, the wafer mounting table 5 is automatically moved based on the pre-input coordinate information (S2). Here, the alignment point A will be described as the upper left corner of the upper left chip of the pattern on the surface of the wafer 7 when the notch position is in the negative Y-axis direction. In addition, for the alignment point A, it is assumed that coordinates when there is no deviation in the rotation direction are input in advance by the input device and stored in the storage unit of the control unit. It is assumed that the eyepiece of the microscope 3 is provided with a cross reticle so that the center position (optical axis position) can be seen.

  If there is a displacement between the center position of the observed image and the position of the alignment point A (S3), the center position of the observed image and the position of the alignment point A are matched by operating the joystick 2 ( S4). Further, the coordinates of the alignment point A at this time are stored.

  Next, the stage 4 automatically moves the wafer mounting table 5 so that the alignment point B on the wafer 7 becomes the center position of the observation image of the microscope 3 based on the reticle that indicates the optical axis of the microscope 3. (S5). Here, description will be made assuming that the alignment point B is a position facing the alignment A turned back by a line connecting the center of the wafer 7 and the notch, that is, the upper right corner of the upper right chip of the pattern on the surface of the wafer 7. In this description, the uppermost chip is used, but it is desirable that the farthest chip in the same row be at the same height in the Y-axis direction. Similarly to the alignment point A, the alignment point B is preliminarily input with coordinates when there is no deviation in the rotation direction and stored in the storage unit of the control unit.

  If there is a displacement between the center position of the observed image and the position of the alignment point B (S6), the center position of the observed image and the position of the alignment point B are matched by operating the joystick 2 ( S7). Then, the coordinates are stored.

  Here, when moving from the alignment point A to the alignment point B, if there is no angular shift in the rotation direction, the alignment point B should come to the center position of the observation image only by moving in the X direction. However, as shown in FIG. 4, the alignment point B is deviated from the center position of the observation image, and it may be necessary to match the position of the alignment point B with the center position of the observation image by operating the joystick 2. This means that the vertical and horizontal arrangement directions of the pattern on the surface of the wafer 7 do not match the movement direction of the electric XY stage, that is, the alignment is not achieved. In this case, in order to perform observation with the microscope 3, it is necessary to align the rotation angle of the wafer 7.

Therefore, the rotation angle of the wafer 7 is calculated based on the coordinates of the alignment point A and the alignment point B, and the wafer mounting table 5 is rotated based on the rotation angle (S8). A specific method in this case will be described below with reference to FIG.
The coordinates of the alignment point A and the alignment point B in the ideal state when there is no deviation of the rotation angle are input in advance. In S3 or S4, the point A is aligned with the center of the observation image as the alignment point A, and the coordinates are registered by the operation unit. In S5, according to the relative coordinate information of the input alignment point B with the alignment point A, only the wafer mounting table 5 is moved and moved to the B point where the alignment point B should be. There is an alignment point B at the point. Therefore, the stage 4 and the wafer mounting table 5, that is, the electric XY stage are moved by the joystick 2, the center of the observation image is aligned with the point B ', and the coordinates are registered by the operation unit. In S8, the deviation θ (degrees) in the rotation angle is derived from the coordinates of the points A and B ′. Then, by rotating the wafer 7 clockwise by θ (degrees), it is possible to know the deviation of the rotation angle, so that the wafer mounting table 5 is automatically moved by a preset program, and the wafer mounting table 5 The pin 6 fixed to the microscope 3 and the pin 8 fixed to the microscope 3 are brought into contact with each other to apply a rotational force to the wafer mounting table 5. Rotate around 9.

FIG. 5 shows a state where the pin 8 is brought into contact with the knob 6 to correct the rotational angle deviation. As shown in FIG. 5, by bringing the knob 6 and the pin 8 into contact with each other, alignment of the pattern arrangement direction on the surface of the wafer 7 and the movement direction of the electric XY stage can be achieved.
Thereafter, as shown in FIG. 6, the wafer mounting table 5 is moved again to the observation position of the microscope 3, and the wafer 7 is observed with the microscope 3.

  As described above, according to the substrate inspection apparatus 1 according to the present embodiment, the electric XY stage is operated by the joystick 2 so that the knob 6 fixed to the wafer mounting table 5 is fixed to the pin 8 fixed to the base 16. By abutting, it is possible to apply a rotational force around the rotation axis 9 to the wafer mounting table 5 and to rotate the wafer mounting table 5 supported rotatably. Accordingly, the rotation angle alignment can be performed by rotating the wafer mounting table 5 and the wafer 7 mounted thereon without requiring a rotation motor or the like for rotating the wafer mounting table 5.

[Second Embodiment]
Next, a second embodiment of the present invention will be described below.
The substrate inspection apparatus according to the present embodiment is different from the first embodiment in that the rotation angle of the wafer 7 is detected by a sensor and the rotation angle is aligned. Hereinafter, with respect to the substrate inspection apparatus according to the present embodiment, description of points that are the same as those of the first embodiment will be omitted, and differences will be mainly described.

  As shown in FIG. 8, the substrate inspection apparatus 20 according to this embodiment includes a notch sensor 21 that is fixed with respect to the rotation direction of the wafer mounting table 5 and detects a notch provided at a predetermined position of the wafer 7. Yes. The notch sensor 21 is a transmission sensor in which a light emitting element and a light receiving element are provided so as to sandwich an end portion of the wafer 7, and is provided on the stage 4. As shown in FIG. 13, the notch sensor 21 shields light from the light emitting element at the outer peripheral portion of the wafer 7 when the rotational angle is misaligned. Further, as shown in FIG. 14, when there is no deviation of the rotation angle, the light from the light emitting element passes through the notch and is detected by the light receiving element. In the case where there is a problem up to a minute angle deviation, the alignment may be taken when the amount of transmitted light exceeds a predetermined amount.

The operation of the substrate inspection apparatus 20 having the above configuration will be described below in accordance with the flowchart shown in FIG.
First, the wafer mounting table 5 is moved to the receiving position of the wafer 7, and the wafer 7 is mounted on the wafer mounting table 5 on the stage 4 (S11).
In step S <b> 12, the control unit moves the stage 4 and the wafer mounting table 5 to bring the knob 6 and the pin 8 into contact with each other. At this time, the position of the wafer mounting table 5 is set to a preset position. Then, the stage 4 is moved in the Y direction, and a rotational force is applied to the wafer mounting table 5. As a result, the wafer mounting table 5 that is rotatably supported is rotated about the rotation axis 9. By the rotation, the notch sensor 21 detects a change in the light amount as shown in FIG. 12, and detects the peak angle as a notch (S12).
Here, assuming that the position of the wafer mounting table 5 in the X-axis direction is a set position, the relationship between the position of the stage 4 in contact with the knob 6 and the pin 8 in the Y-axis direction and the rotation angle of the wafer mounting table 5 is determined in advance. It shall be created as a lookup table.

Then, in order to make the angle detected as a notch by the control unit, by bringing the knob 6 into contact with the pin 8 again, as shown in FIG. 9, the pattern arrangement direction on the surface of the wafer 7 and the movement direction of the electric XY stage. Can be easily matched (S13).
Thereafter, as shown in FIG. 10, the wafer mounting table 5 is moved again to the observation position of the microscope 3, and the wafer 7 is observed by the microscope 3.

  As described above, according to the substrate inspection apparatus 20 according to the present embodiment, the notch sensor 21 detects the rotation angle of the notch provided at a predetermined position of the wafer 7, and the electric XY stage is installed based on this rotation angle. By rotating the wafer mounting table 5 by operating it, alignment of the rotation angle can be performed.

As mentioned above, although each embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and includes design changes and the like without departing from the gist of the present invention. It is.
For example, in the first embodiment, the alignment points A and B have been described as being the outer edge of the pattern on the surface of the wafer 7, but any positional relationship that can calculate the rotation angle of the wafer 7 may be used. For example, the alignment points A and B may be point symmetric with respect to the center of the wafer 7. Further, the shift of the rotation angle may be detected by adjusting with the joystick 2 after moving from the alignment point A to the alignment point B based on the design data.

In the second embodiment, it has been described that the notch of the wafer 7 is detected. For example, in the case of orientation flat, the relationship between the rotation angle and the amount of light is graphed, and the midpoint of the detected high amount range is obtained. Thus, the rotation angle of the wafer 7 may be aligned.
Further, in each embodiment, it has been described that one pin 8 is provided. However, two or more pins 8 may be arranged at intervals in the Y-axis direction to reduce the operation of the electric XY stage. In other words, when one is rotated in the reverse direction, it is necessary to detour the pin 8 once so as to push the non-contact side of the knob 6, whereas it is reversed only by moving in the reverse direction in the Y-axis direction. Rotation is possible. The same effect can be obtained by using two knobs 6 and one pin 8.
Further, the pin 8 has been described as having a shape extending in the normal direction of the wafer 7, but instead of this, for example, it may be a V-groove provided in the base 16, and the wafer mounting table 5 is brought into contact with the knob 6. Any shape can be used as long as a rotational force can be applied thereto.

1 is a plan view of a substrate inspection apparatus according to a first embodiment of the present invention. It is a front view of the board | substrate inspection apparatus of FIG. It is a flowchart which shows operation | movement of the board | substrate inspection apparatus which concerns on 1st Embodiment. It is a figure explaining operation | movement of step S4 of FIG. It is a figure explaining operation | movement of step S8 of FIG. It is a figure explaining the operation | movement after the process completion | finish of FIG. It is a flowchart which shows operation | movement of the board | substrate inspection apparatus which concerns on 2nd Embodiment. It is a figure explaining operation | movement of step S11 of FIG. It is a figure explaining operation | movement of step S13 of FIG. It is a figure explaining the operation | movement after completion | finish of the process of FIG. It is a figure explaining the calculation method of a rotation angle. It is a figure explaining the change of the light quantity at the time of detecting a notch. It is a figure explaining the state with the shift | offset | difference of a rotation angle. It is a figure explaining the state without the shift | offset | difference of a rotation angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Board | substrate inspection apparatus 2 Joystick 3 Microscope 4,40 Stage 5 Wafer mounting stand 6 Knob 7 Wafer 8 Pin 10 Cassette 16 Base 21 Notch sensor

Claims (3)

A rotary mounting table for mounting a substrate and rotatably supporting the substrate around a normal line;
A stage unit that supports the rotary mounting table and moves in a plane parallel to the substrate;
An operation unit for moving the stage unit;
A lever portion fixed to the rotary mounting table and extending in a radial direction of the substrate;
An observation unit for observing the surface of the substrate on the rotary mounting table;
A substrate inspection apparatus comprising: an abutting portion that is fixed with respect to the observation portion within an operating range of the lever portion by the stage portion and extends in a normal direction of the substrate.   The substrate inspection apparatus according to claim 1, wherein a rotation angle of the substrate is calculated based on a pattern of the substrate surface observed by the observation unit, and the stage unit is moved based on the rotation angle. A sensor that is fixed with respect to the rotation direction of the substrate and detects a rotation angle of the substrate;
The substrate inspection apparatus according to claim 1, wherein the stage unit is moved based on a rotation angle detected by the sensor.

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