JPH076754U - Appearance inspection device - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to provide a visual inspection apparatus that automates the transition from macro observation to micro observation and simplifies coordinate input of defects. [Structure] This appearance inspection apparatus includes stages 14 and 15 that are movable in the observation regions of a macro observation system 17, a micro observation system 18, a macro observation system 17, and a micro observation system 18,
First image input means 2 for capturing an image of the macro observation system 17
2, second image input means 27 for capturing an image of the micro observation system 18, and monitor means 39 for visualizing the captured image. Further, the attention site of the image captured and displayed by the macro observation system 18 is designated by the coordinate designating means 41, and the input coordinates are converted into the coordinates on the stage by the stage controlling means,
Further, the stage control amount for moving the attention site to the optical axis position of the micro observation system 18 is calculated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a visual inspection apparatus used for visual inspection of an object such as a wafer or a liquid crystal glass substrate. More specifically, a macro observation system and a micro observation system are arranged on the same stage, and the macro observation system to the micro observation system are arranged. The present invention relates to a visual inspection device capable of switching to.

[0002]

[Prior art]

 In the manufacturing process of wafers, liquid crystal glass substrates, etc., the existence of defects on the substrate is inspected at each film forming process, pattern baking process and etching process. For example, in the inspection of a liquid crystal TFT substrate, macroscopic observation is performed in each process to detect defects on the substrate, and if a defect is found on the substrate, the defective portion is marked. Next, the defects found by macro observation were inspected in detail by micro observation with a microscope.

However, the macro observation and the micro observation are performed separately on each stage, and in the micro observation, the defects (marks) on the substrate can be visually observed by relying on the marks made in the macro observation. ) Had to be positioned at the optical axis position of the objective lens provided in the micro observation system, and the work was extremely complicated.

[0004]

[Problems to be solved by the device]

 Under the above technical background, in the Japanese Patent Application No. 4-132577, the present applicant arranges a macro observation system and a micro observation system on the same stage so that the defect portion found by macro observation can be easily micro observed. We are proposing a visual inspection device that can be moved below the optical axis of the system.

As shown in FIG. 13, such an apparatus includes an apparatus body 1, a stage 2 movably attached to the apparatus body 1 in the X direction, and a macroscopic observation held by the apparatus body 1 and arranged on the stage 2. Coordinate display device for displaying relative coordinates among the micro observation system 4, the macro observation system 3, and the micro observation system 4, which are held on the system 3 and the apparatus body 1 and arranged on the stage 2 adjacent to the macro observation system 3. It has 5 mag.

In such an apparatus, the defective portion found in the macro observation system 3 is sequentially arranged at the spot illumination position S of the spot illumination device 6, and the foot switch 7 is pressed each time to display the defect on the coordinate display device 5. Enter the coordinates. When moving the defective portion to the micro observation system, the stage 2 is moved to the micro observation system while the substrate is still mounted on the stage 2, and the stage 2 is moved so that the relative coordinates displayed on the coordinate display device 5 become zero. By moving, the defective portion can be aligned with the optical axis position of the objective lens 8.

However, in the above-described appearance inspection apparatus, in order to input the coordinates of the defective portion found on the substrate, the defective portion must be arranged at the spot illumination position S. In reality, it is necessary to move the large stage 2 to superimpose the defective portion on the spot dropped on the substrate. Such a work imposes a great burden on the observer because the large stage 2 must be finely adjusted.

Further, the work of superposing the defective portion on the spot dropped on the substrate involves searching for the defect in such a posture as to cover the substrate on the stage 2, so that dust can drop on the substrate from the operator. There is a problem that the property is high.

The present invention has been made in view of the above-mentioned circumstances, can automate the transition from macro observation to micro observation, and can reduce the stage operation at the time of inputting the coordinates of the defect portion, It is an object of the present invention to provide an appearance inspection device that can reduce the possibility of dust falling on a substrate from an operator and can acquire data necessary for quality control of processes such as classification and number of defects. .

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the appearance inspection apparatus of the present invention comprises a macro observation system that captures object light from a subject placed in a macro observation area and forms a subject image enlarged or reduced at a predetermined magnification. , A micro observation system that captures the object light from the subject placed in the micro observation region and forms a magnified image at a magnification greater than that of the macro observation system, and the macro observation while the subject is mounted A stage movable in the observation areas of both the optical system and the micro optical system, first image input means for converting an object image formed by the macro observation system into an image signal, and the micro observation system. Second image input means for converting the formed subject image into an image signal, and visualizing the image signal of each subject image converted by the first image input means and the second image input means. Monitoring means, The coordinate designation means for designating the coordinates of the region of interest of the subject image captured by the macro observation system and displayed by the monitor means and storing each designated coordinate, and the optical axis position of the micro observation system with respect to the stage origin. Is stored in advance, and the designated coordinates of the region of interest stored in the coordinate designating means are converted into coordinates on the stage, and the region of interest is identified from the converted coordinates, the optical axis position of the micro observation system, and the current position of the stage. Stage control means for calculating a stage control amount for moving to the optical axis position of the micro observation system.

Further, in addition to the above-mentioned configuration, the appearance inspection apparatus of the present invention has one of the areas adjacent to the area which is the current coordinate input target on the monitor screen on which the object image is displayed by the monitor means. Area display means for displaying up to a part, and if there is a target site whose coordinates have already been designated by the coordinate designating means outside the area for the coordinate input target, the coordinate input mark is displayed on the target site, and If there is a coordinate input by the coordinate designating means in the area, a mark displaying means for sequentially displaying the coordinate input completed mark is provided at that portion.

[0012]

[Action]

 According to the appearance inspection apparatus of the present invention, the subject image formed by the macro observation system is converted into the image signal by the first image input means, and the image signal is visualized by the monitor means. When the coordinates of the region of interest of the subject image displayed on the monitor means are designated by the coordinate designation means, the designated coordinates are stored. The stage control means converts the designated coordinates of the region of interest into coordinates on the stage, and the stage for moving the region of interest to the position of the optical axis of the micro observation system from the transformed coordinates, the position of the optical axis of the micro observation system, and the stage position. The controlled variable is calculated. If the stage is driven with this calculated stage control amount, the region of interest can be moved to the optical axis position of the micro observation system.

Further, according to the appearance inspection apparatus of the present invention, a part of the adjacent area is also displayed in the coordinate input target area by the area display means on the monitor screen of the monitor means. The mark display means performs the following processing on this display screen. That is, if there is a region of interest that has already been coordinate-designated by the coordinate designating means outside the coordinate input target area, the coordinate-designated mark is displayed on the target region. Further, if there is a coordinate input by the coordinate designating means in the designated area, the coordinate input completed mark is successively displayed at that portion.

[0014]

【Example】

 Embodiments of the present invention will be described below. FIG. 1 shows a functional configuration of an appearance inspection apparatus according to an embodiment of the present invention, and FIG. 2 shows an appearance of the apparatus.

In the appearance inspection apparatus of this embodiment, a pair of guide rails 12 are arranged on the upper end surface of a microscope base 11 in the Y direction, and a Y stage 13 is slidable on the guide rails 12. It is placed in. The central portion of the Y stage 13 is opened in a rectangular shape, and a pair of guide rails 14 are arranged so as to sandwich the opening in the X direction. An X stage 15 is mounted on the guide rail 14 so as to be movable in the X direction. Hereinafter, when the Y stage 14 and the X stage 15 are collectively referred to, they are referred to as an XY stage.

An arm 16 fixed to the microscope base 11 is provided above the XY stage. Above the moving area of the X stage 15, a macro observation system 17 held by the arm 16 is arranged at one end side in the X direction, and a micro observation system 18 held by the arm 16 is arranged at the other end side in the X direction. ing.

The macro observation system 17 includes a macro illumination device 19 for macro-illuminating the macro observation area S around the observation optical axis, a wide field of view, and a low-magnification (about 1/40 to 1/5) TV lens 21, It is provided with a macro TV camera 22 which converts a board image taken in through the TV lens 21 into a TV signal.

The micro-observation system 18 is incorporated from the objective lens 25, a microscope including a micro-illuminator 23 for illuminating a micro-observation region around the observation optical axis (objective optical axis), an objective lens 24 and an eyepiece lens 25, and the like. A micro TV camera 27 for projecting the defective image onto a light receiving surface through a TV camera lens 26 and converting it into a TV signal is provided.

As shown in FIG. 1, the appearance inspection apparatus includes a motor 31 that serves as a power source for moving the XY stage. When the computer 32 gives a command to the controller 33, the controller 33 controls the driving amount of the motor 31 via the driver 34.

A scale 35 is provided on the side surface of the XY stage, and a scale of the scale 35 is read by a sensor 36 and output to a scale counter 37. The count value of the scale counter 37 is input to the computer 32 via the controller 33.

Each TV signal from the macro TV camera 22 and the micro TV camera 27 is input to the switch 38. The switch 38 selects one of the TV signals according to the switching signal given from the computer 32 and sends it to the display device 39.

A mouse 41 forming part of the coordinate designating means is connected to the computer 32, and a mouse mark is displayed on the screen of the display device 39 by the image processing circuit 42. It should be noted that, in the present embodiment, the term "coordinates" means the position from the origin set in advance for the XY stage.

The mouse 41 is provided with an input button 41a for instructing coordinate input and a cancel button 41b for canceling input coordinates. Further, a floppy disk 43 and a keyboard 44 are connected to the computer 32.

The illumination area S of the macro illumination device 19 has a diameter of about 100 mm. If the magnification of the TV lens 21 of the macro TV camera 22 is 1/10 and the size of the image pickup tube of the macro TV camera 22 is 2/3 inch, the actual light receiving surface is about 8 × 6 mm. It is a value obtained by multiplying the diagonal length of an 8 × 6 mm rectangle by 10 mm by the lens magnification. However, this setting should be set considering the moire caused by the liquid crystal pattern and the size of the camera, and the above setting is used here for the sake of clarity. The actual size of one area is 80 × 60 mm (corresponding to 8 × 6 mm on the light receiving surface of the TV camera 22).

In the present embodiment, as shown in FIG. 5, the substrate 10 is divided into a matrix of 6 × 5, and macroscopic observation is sequentially performed in the order of A1, A2, ..., F5, F6. Put the ram together. Therefore, the distance L1 between the optical axis of the macro observation system 17 and the optical axis of the object lens 24 of the micro observation system 18 and the origin coordinates set in the X stage 13 and the Y stage 15 are stored in the computer 32 in advance. Further, regarding each area, the coordinates at which the center of the area matches the center of the optical axis of the TV camera 22 (matches the center of the monitor screen) are obtained and set in advance in the computer 32.

Next, the operation of this embodiment configured as described above will be described with reference to FIGS. 3 and 4. When the computer 32 receives the macro observation request from the keyboard 44, it determines the current coordinates of the XY stage from the value of the scale counter 37 and instructs the controller 33 to match the coordinates of the XY stage with the center coordinates of the area A1. The controller 33 controls the driver 34 by sending a command. At the same time, a switching signal is sent to the switching device 38 to select the TV signal from the macro TV camera 22 and input it to the display device 39. As a result, as shown in FIG. 6, on the monitor screen M of the display device 39, a macro observation image (substrate image) in which the center of the area A1 comes to the monitor center O is displayed. Also, a mouse mark Q is displayed on the same screen M.

Here, the observer operates the mouse 41 to overlay the mouse mark Q on the defective portion on the monitor screen M, and presses the input button 41 a of the mouse 41. When the input button 41a of the mouse 41 is pressed, the distance L2 between the mouse mark position on the monitor screen M and the monitor center O is read by the image processing circuit 42. The read distance L2 is converted into a value corresponding to the magnification of the TV lens 21, and converted into coordinates on the XY stage. The input coordinates of the defective portion thus obtained are stored in the storage unit together with the defective portion number. The defective part number shall be numbered by the serial number. The computer 32 accepts the type of defect from the keyboard 44 at the same time when the coordinates of the defective portion are input. For example, the defect types are assigned in advance to the numeric keys (1 to 30) of the keyboard. The computer recognizes the type of defect, such as "scratch" for the 1st key and "particles" for the 2nd key.

In the computer 32, marks having different shapes stored in advance according to the type of defect are displayed so as to be superimposed on the defective portion on the monitor screen. In the example shown in FIG. 6, a defective portion recognized as a “scratch” is indicated by a round mark R.

Next, if there is an instruction to end the coordinate input in the area A1, the process moves to the next area A2. In changing the area, the current coordinates of the XY stage and the coordinates after movement are known in advance, so a stage control amount that allows the center of the adjacent area to coincide with the center of the monitor screen is set in advance. By driving the motor 31 by the stage control amount, the XY stage moves as much as the center of the adjacent area coincides with the center of the monitor screen.

When the macro observation of all areas is completed as described above, the micro observation is executed while waiting for the micro observation request. When the computer 32 receives the micro observation request from the keyboard 44, it sends a switching signal to the switch 38 to input the TV signal of the micro TV camera 27 to the display device 39, and to detect the defective portion stored during macro observation. Input coordinates are read in order from the smallest defect number. Then, based on the count value of the scale counter 37, the optical axis position coordinates of the micro observation system with respect to the origin of the XY stage, and the input coordinates of the read defect portion, the defect portion is moved to the optical axis position of the micro observation system. The amount of stage control required for this is calculated, and the motor 31 is driven according to the calculated amount of stage control.

When the defective portion comes directly below the optical axis of the microscopic observation system by the XY stage driven by the above-mentioned stage control amount, the defective portion arranged on the optical axis is spot-illuminated by the illumination device 23. An image of the illuminated defect portion is magnified at a high magnification by the observation optical system (objective lens 24 etc.) of the microscope and forms an image on the light receiving surface of the micro TV camera 27.

Here, in reality, the image is not captured by the high-magnification objective lens 24 in one stage control, and a relatively low magnification is used in the first stage control in consideration of the coordinate accuracy in macro observation. Focusing is performed with a (5 ×, 10 ×) objective lens. Next, bring the defect image projected on the monitor screen to the center of the monitor screen, switch to a high-magnification object lens, and perform detailed observation.

Next, the computer 32 waits for an instruction to change the defective portion from the keyboard 44, judges whether or not the stored defective portion remains if the change instruction is input, and if it remains, Read the input coordinates of the next defective part number. If all the coordinates input in macro observation are read out and there are no remaining coordinates, micro observation ends.

When the coordinates and type of the defect portion are input as described above, an application program that creates a histogram, pie chart, etc. is started as necessary, and the machining data is fed back to the previous process. , Used for preparation of post-process.

As described above, according to this embodiment, the macro observation image is displayed on the monitor screen, the defective portion is designated by using the mouse 41 on the screen, and the position of the designated defective portion is displayed on the stage. The coordinates of the defect are automatically converted and stored, and when the micro observation is performed, the XY stage is controlled so that the defect is sequentially moved to the position directly below the optical axis of the micro observation system, so it is extremely easy to input the coordinates of the defect. In addition, since it is not necessary to look for a defective portion with the naked eye at the time of microscopic observation, dust and the like do not fall on the substrate 10 from the observer, so that the contamination property is improved.

Further, according to the present embodiment, since the defect type is also input at the time of inputting the coordinates of the defect portion in macro observation, it is possible to acquire data necessary for quality control such as the type and number of defects.

By the way, if the macro observation area (coordinate input range) is displayed on the entire surface of the monitor screen, it is difficult to observe the defect at the boundary between the relevant area and the adjacent area, and it is also possible to display up to the adjacent area. There is a possibility that you may not know whether or not it has been completed.

Therefore, such a problem can be solved by adopting the coordinate input screen system as shown in FIGS. In the above embodiment, the TV lens 21 of the macro TV camera having a magnification of 1/10 × was used to display a single area on the entire monitor screen. However, in this modification, for example, the TV lens 21 has a 1/15 × magnification. The area corresponding to the corresponding area (80 mm × 60 mm) is surrounded by a frame on the monitor screen and the coordinate input target range and the other area are divided.

Processing when the area C4 is displayed as a coordinate input target area on the monitor will be described with reference to FIGS. 7 and 9. In this modification, the center of the area C4 is arranged at the optical axis position of the macro observation system, and the macro observation image is captured via the TV lens having a real visual field larger than one area. The captured macro observation image is displayed on the monitor screen with the center of the area C4, which is the area for coordinate input, as the monitor center.

Next, on the monitor screen M, a frame indicating the area N of the area C4 that is the coordinate input target area is displayed in an overlapping manner. The observer can recognize that the area N is a coordinate input target area.

On the other hand, in the macro image displayed on the monitor screen M, it is determined whether or not there is a defective portion that has been input in an area other than the area C4. Since macro observations have been made for A1 to C3, there is a possibility that there is a defective portion that has already been input in those areas. When there is a defective portion that has already been input in an area other than the area C4, the input mark R is displayed over the corresponding defective portion.

If the coordinates of the defective portion are input to the area C4, the input coordinates are stored together with the defective portion number, and the input completed mark is displayed at the relevant portion. According to this modification, the surrounding area of the coordinate input target area is displayed on the same screen, and if there is any defective area coordinate input in the surrounding area, the input mark is displayed. In addition, it becomes easy to judge whether or not the input has been completed at the boundary between the adjacent areas, and it is possible to prevent an input error or an error such as double input.

Further, as shown in FIG. 8, the movement amount per step when changing the area is made smaller than that in the above-described embodiment, and a part of the adjacent area is displayed. In this case, a 1/10 × TV lens can be used as in the above embodiment. In FIG. 8, the shaded area A2 is the coordinate input target area, and it can be recognized from the screen that the defect A at the boundary between the areas A1 and A2 has been input at the time of the inspection of the area A1.

In the macro observation system of the above-mentioned embodiment, the substrate 10 is irradiated with the focused light, but the illumination light not particularly focused may be used. 10 to 11 (a) and (b) show modifications of the illuminating device in the macro observation system of the above embodiment.

The modified example shown in FIG. 10 is an example of an interference optical system in which the light emitted from the optical fiber 51 is incident on the lens 53 by the half mirror 52 and the interference light is applied to the substrate 10. The reflected light from the substrate 10 illuminated by the interference optical system is captured by the TV camera and displayed.

In this modification, the film unevenness is mainly inspected. Further, when the TV lens 21 is arranged at a distance from the light emitted from the fiber 51 to the collimator lens 53, that is, at a position conjugate with the focal length of the collimator lens 53, the TV lens 21 has a filament image from an illuminating device (not shown). It is impossible to inspect the film for unevenness because it takes in. Therefore, the TV lens 21 is not arranged at the conjugate position, but is arranged at a position farther from the optical axis of the collimator lens 53 than the conjugate position.

In the modification shown in FIGS. 11A and 11B, a fiber group 54 in which a large number of optical fibers are linearly bundled is irradiated at an angle nearly parallel to the substrate 10. The reflected light of the light obliquely incident on the substrate 10 is condensed by the lens 55 and incident on the TV lens 21 to obtain a macro observation image.

According to this modification, the LCD pattern on the substrate 10 disappears, and only the reflected light at the dust and scratch portions enters the TV camera. Therefore, the influence of moire on the light receiving surface of the TV camera 22 can be eliminated. There are advantages.

FIG. 12 shows a modification of the coordinate input means which replaces the mouse in the above embodiment. In this modification, in a box 56 with a built-in trackball 55, alphabet keys A to D, numeric keys 1 to 4, keys A-1 to A-4 for classifying defect types, and coordinate input. It has an input button for instructions and a cancel button for cancellation. For example, on the computer side, A-1 is recognized as a large scratch, A-2 is recognized as a small scratch, A-3 is recognized as a large dust, and A-4 is recognized as a small dust. The specified individual processing is executed.

Alternatively, the numbers 1 to 30 corresponding to the types of defects are displayed on the monitor screen, and after the defect is input, the matching mark is input to the number and the computer recognizes the type of the defect from this input. Also, it may be configured so that the observer can recognize it later.

The coordinate input means is not limited to the mouse, and a panel called a digitizer having a signal line may be used. By applying a probe to the panel, a mark will appear at the corresponding position on the monitor screen corresponding to the probe position on the panel. The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

[0052]

[Effect of device]

 As described above in detail, according to the present invention, the transition from macro observation to micro observation can be automated, the stage operation can be reduced when inputting the coordinates of the defect portion, and the operator can change the position on the substrate. It is possible to provide a visual inspection apparatus that can reduce the possibility of dust falling and can acquire data necessary for quality control of processes such as classification and number of defects.

[Brief description of drawings]

FIG. 1 is a functional configuration diagram of a visual inspection apparatus according to an embodiment of the present invention.

FIG. 2 is an external view of the appearance inspection device shown in FIG.

3 is a flowchart showing a part of the operation contents of the appearance inspection device shown in FIG.

FIG. 4 is a flowchart showing another part of the operation content of the appearance inspection device shown in FIG.

FIG. 5 is a diagram showing a divided state when macro-observing a substrate.

FIG. 6 is a diagram showing a monitor screen on which a macro observation image is displayed.

FIG. 7 is a diagram showing a modification of the display method of the macro observation image on the monitor screen.

FIG. 8 is a diagram showing another modification of the display method of the macro observation image on the monitor screen.

9 is a flowchart showing a main part of the operation content of the modified example shown in FIG.

10 is a diagram showing a modified example of the illumination device in the visual inspection device shown in FIG.

FIG. 11 is a diagram showing another modification of the illumination device in the visual inspection device shown in FIG. 1.

12 is a diagram showing a modified example of the coordinate input means in the visual inspection apparatus shown in FIG.

FIG. 13 is a perspective view of an appearance inspection apparatus in which a macro observation system and a micro observation system are linked.

[Explanation of symbols]

10 ... Substrate, 13 ... Y stage, 15 ... X stage, 1
7 ... Macro observation system, 18 ... Micro observation system, 19 ... Macro illumination device 21, 26 ... TV lens, 22 ... Macro TV
Camera, 23 ... Micro illumination device, 24 ... Objective lens, 2
7 ... Micro TV camera, 32 ... Computer, 39 ... Display device, 41 ... Mouse.

Claims (2)

[Scope of utility model registration request] 1. A macro observation system that takes in object light from a subject arranged in a macro observation region to form a subject image enlarged at a predetermined magnification, and an object from the subject arranged in a micro observation region. A micro observation system that captures light and forms a magnified image at a magnification greater than that of the macro observation system, and the observation areas of both the macro observation system and the micro optical system in a state where the subject is mounted. A movable stage, a first image input unit that converts an object image formed by the macro observation system into an image signal, and a second image input unit that converts the object image formed by the micro observation system into an image signal Image input means, monitor means for visualizing the image signals of the respective subject images converted by the first image input means and the second image input means, and the monitor means taken in by the macro observation system. Displayed in The coordinate designation means for designating the coordinates of the designated region of the subject image and storing each designated coordinate, and the optical axis position of the micro observation system with respect to the origin of the stage are stored in advance, The designated coordinates are converted into coordinates on the stage, and the stage control amount for moving the attention site to the optical axis position of the micro observation system is calculated from the converted coordinates, the optical axis position of the micro observation system, and the current position of the stage. An external appearance inspection device comprising: 2. An area display means for displaying a part of an area adjacent to an area which is a current coordinate input target on a monitor screen on which the subject image is displayed by the monitor means, and the coordinate input target. If there is a target area whose coordinates have already been designated by the coordinate designating means outside the area, a mark with coordinates input is displayed on the target location, and if there is coordinate input by the coordinate designating means in the area for coordinate input. 2. The appearance inspection apparatus according to claim 1, further comprising mark display means for sequentially displaying the coordinate input mark at that portion.