TW201945689A - Appearance inspection device and appearance inspection method - Google Patents

Abstract

The present disclosure provides an appearance inspection device comprising: a visual designation means for indicating a visual designation position of a main surface of a large photomask; a visual designation information acquisition means for acquiring visual designation information; a two-dimensional coordinate calculation means for calculating two-dimensional coordinates of the main surface indicating the visual designation position from the visual designation information; a microscope capable of moving each position of the main surface to an observable position; a microscope driving means for moving the microscope to a position where the position of the main surface indicated by the two-dimensional coordinates can be observed; and a two-dimensional coordinate input means for inputting a two-dimensional coordinate indicating an arbitrary position of the main surface of the large photomask.

Description

Appearance inspection device and appearance inspection method

The invention relates to an appearance inspection device and an appearance inspection method used for the appearance inspection of a large-scale photomask.

The large photomask is used for various pattern formation in, for example, a photolithography process at the time of manufacturing a flat panel display or a color filter, and more specifically, an exposure process.

In the manufacturing process of large photomasks, there may be cases where the transfer pattern is uneven due to the line width or formation position of the transfer pattern slightly deviating from the design. In addition, in the manufacturing process or the washing process, spots, dirt, and foreign matter may adhere to the transfer pattern or form a scar. There are cases in which defects such as unevenness and spots are more easily detected using a macroscopic observation, which is observed globally with visual observation, rather than a microscopic observation, which is observed in detail with a microscope. Therefore, in the inspection of these defects, for example, as described in Patent Document 1, it is often the case that a macroscopic observation is performed using an appearance inspection device.

As an appearance inspection device that performs macroscopic observation, there are known devices that inspect glass substrates for liquid crystal displays in addition to large photomasks. In such an appearance inspection device, a defect in the main surface of a sample to be inspected is detected by macroscopic observation, and the defect is analyzed in detail by microscopic observation.

For example, Patent Documents 2 to 4 describe appearance inspection devices that detect such defects by microscopic observation and macroscopic observation.

[Prior technical literature]
[Patent Literature]
[Patent Document 1] Japanese Patent Laid-Open No. 2013-45797
[Patent Document 2] Japanese Patent Laid-Open No. 2008-175548
[Patent Document 3] Japanese Patent Laid-Open No. 4-151547
[Patent Document 4] Japanese Patent Laid-Open No. 2005-164610

[Problems to be solved by the invention]

In the macro observation, it is necessary to obtain the defect position with high accuracy. Furthermore, after a defect of the main surface of a large mask is detected by microscopic observation, the macroscopic observation may be used again to inspect the defect or its corrected portion. However, in the visual inspection device and the visual inspection method using the same as described above, the defect or its corrected portion detected by microscopic observation cannot be indicated visually. Therefore, it is not easy to macroscopically observe the defect or its correction portion.

The main object of the present invention is to provide an appearance inspection device and an appearance inspection method that can accurately obtain the position of a defect in macroscopic observation, and can visually indicate a defect detected by microscopic observation or a correction portion thereof.
[Technical means to solve the problem]

In order to solve the above problems, the present invention provides an appearance inspection device, which is characterized by including: a visual designation device that indicates a visual designation position of a main surface of a large mask indicated based on visual observation; a visual designation information acquisition device that acquires a visual designation Information; a two-dimensional coordinate calculation device that calculates two-dimensional coordinates of the main surface of the large-scale photomask representing the visually-designated position according to the visually-designated information; a microscope that can be moved to positions capable of observing the main surface of the large-scale photomask Position of a microscope driving device that moves the microscope to a position where the main surface of the large-scale photomask shown by the two-dimensional coordinates can be observed; and a two-dimensional coordinate input device whose input represents the main of the large-scale photomask The two-dimensional coordinates of the arbitrary position of the face.

According to the present invention, it is possible to easily perform a defect inspection using an appearance inspection including both macro observation and micro observation.

In the above invention, it is preferable to include a visual designation information calculation device that calculates the visual designation information based on the two-dimensional coordinates inputted through the two-dimensional coordinate input device.

In the above invention, it is preferable that the visual designation information acquisition device acquires the visual designation information indicating an area having an area. The reason is that it is more effective to investigate the cause of unevenness, dirt, etc. caused by the line width of the transfer pattern, designate the area of the defect, and measure the line width, reflectance, and transmittance.

In the above invention, it is preferable to further include a plurality of observation illuminations having different types of light sources. The reason is that it is easy to detect a variety of defects in visual observation.

Further, in the above invention, it is preferable to further include a rotation mechanism for rotating the large-sized photomask around a rotation axis parallel to the main surface of the large-sized photomask, and to enable the main surface of the large-sized photomask to automatically rotate. The angle parallel to the floor surface about the rotation axis is 90 ° or more. The reason for this is that visual observation of the front side of the large photomask becomes easy.

In the above invention, the rotatable angle is preferably 270 ° or more. The reason is that visual observation of the back surface of the large-sized photomask becomes easy.

Moreover, in the said invention, it is preferable that it is further equipped with the imaging device which images the main surface of the said large reticle. The reason is that the state of the main surface of the large photomask can be known.

In addition, the present invention provides an appearance inspection method, which is characterized by comprising: a step of obtaining visual designation information, which is to obtain visual designation information of a defect of a main surface of a large mask indicated based on visual observation; a two-dimensional coordinate calculation step, The two-dimensional coordinates of the main surface of the large-scale photomask representing the visually-designated position are calculated according to the above-mentioned visually-designated information; and the microscopic observation step is to observe the position of the main surface of the large-scale photomask shown by the two-dimensional coordinates with a microscope. .

According to the present invention, it is easy to microscopically observe defects detected by macroscopic observation.

Further, in the appearance inspection method, it is preferable that the visually designated information acquisition step is performed in a defect inspection step that inspects the presence or absence of defects existing on the main surface of the large-scale mask by observation of the appearance, and the defect inspection is performed. The steps include irradiating observation illumination at a fixed irradiation angle on the main surface of the large photomask, and setting an irradiation area on the main surface of the large photomask, and inspecting the large photomask by moving the irradiation area up, down, left, and right. The entire surface inspection of the main surface, and the entire surface inspection is performed at least twice by changing the irradiation angle of the observation illumination with respect to the main surface of the large mask.

Furthermore, the present invention provides an appearance inspection method, which is characterized by: a defect correction step for correcting a defect on a main surface of a large photomask; and a visual designation information calculation step for the large light based on the large light indicating a correction part of the defect. The two-dimensional coordinates of the main surface of the mask are used to calculate the visually designated information; and the macroscopic observation step is to visually observe the correction part of the defect according to the visually designated information.
According to the present invention, it is easy to macroscopically observe a defect detected by microscopic observation or a correction portion thereof.

In addition, the present invention provides a defect inspection method, which is characterized in that the main surface of the large photomask is irradiated with observation illumination at a fixed irradiation angle, and an irradiation area is provided on the main surface of the large photomask. The irradiation area is moved up and down and left and right to perform a whole surface inspection for inspecting the entire surface of the main surface of the large-scale photomask, thereby inspecting the presence or absence of defects existing on the main surface of the large-scale photomask, and the entire surface inspection is to change the observation The illumination was performed at least twice with respect to the irradiation angle of the main surface of the large-scale photomask.

In the above defect inspection method, it is preferable that the entire surface inspection includes a low-irradiation angle entire surface inspection performed at an angle in the range of 15 ° to 45 °, and the irradiation angle is 45 ° to 75 °. The whole surface is inspected at a high irradiation angle at an angle within the range.

Furthermore, it is preferable that the entire surface inspection is an entire surface inspection of the entire surface of the large-scale mask by repeating the following steps, that is, irradiating the above-mentioned side from one side of the large-scale mask in a direction orthogonal to the one side. Observation lighting, while moving while inspecting in parallel with the one side, after inspecting the length of the one side, the irradiation area is moved by a specific distance in a direction orthogonal to the one side, and it is particularly preferable for the large light The four sides of the hood are inspected over the entire surface.

In the defect inspection method, it is preferable that the moving speed of the irradiation area in the entire surface inspection is in a range of 5 cm / sec to 9 cm / sec.
In the step of obtaining the visual designation information, it is preferable that the observation illumination alternately repeats the irradiation state and the non-irradiation state of the irradiation light with respect to the main surface of the large-scale photomask by the control unit. Among them, it is preferable to use a control unit to set the above-mentioned observation illumination to the above-mentioned non-irradiated state, and use a laser pointer to obtain a visually designated position of a defect on the main surface of the large photomask, or to alternately switch at high speed. A method for obtaining a visually designated position of a defect on a main surface of a large photomask using a laser pointer in a state where the brightness of the irradiated light on the large photomask is reduced in the above-mentioned irradiated state and non-irradiated state.
[Effect of the invention]

In the present invention, an effect is achieved in that a defect inspection using an appearance inspection including both macro observation and micro observation can be easily performed.

Hereinafter, the appearance inspection device and the appearance inspection method of the present invention will be described in detail.

A. Visual inspection device The visual inspection device of the present invention is characterized by including: a visual designation device that indicates the visual designation position of the main surface of the large-scale mask indicated based on visual observation; a two-dimensional coordinate calculation device that calculates based on the visual designation information The two-dimensional coordinates of the main surface of the large-scale photomask representing the above-mentioned visually designated position; a microscope that can be moved to a position where each position of the main surface of the large-scale photomask can be observed; and a microscope driving device that moves the microscope Observe the position of the position of the main surface of the large photomask shown by the two-dimensional coordinates; and a two-dimensional coordinate input device that inputs a two-dimensional coordinate representing an arbitrary position of the main surface of the large photomask. Here, in the present invention, the "main surface of the large-scale mask" means the front and back surfaces of the large-scale mask.

The structure and operation of an example of an appearance inspection device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view showing an example of an appearance inspection apparatus of the present invention. Furthermore, in FIG. 1, the X1 direction refers to a direction parallel to the floor surface 2, the Y1 direction refers to a direction parallel to the floor surface 2 and is perpendicular to the X1 direction, and the Z1 direction refers to a direction perpendicular to the floor surface 2 direction.

First, the configuration of the visual inspection device 100 shown in FIG. 1 will be described.
As shown in FIG. 1, the visual inspection device 100 includes a base 5 provided on the floor surface 2, a stand 10 provided movably on the base 5, and a substrate support frame 14 provided on the stand 10 via a rotation shaft 12. . As shown in FIG. 1, the appearance inspection device 100 includes a stage 16 provided on the floor surface 2, a laser pointer 20 and a microscope 50 which are mounted on the stage 16, an operation unit 30, and a computer 40. The computer 40 includes a display section 40a, a control section 40b, and a memory section 40c.

The substrate support frame 14 has openings 14a penetrating from the front surface to the back surface. The front surface 70a and the back surface 70b of the large photomask 70 fixed to the substrate support frame 14 can be viewed from the front side and the back surface of the substrate support frame 14 through the opening portions 14a. . The gantry 10 can be moved in the direction of ± Y1 with respect to the base portion 5 by giving a specific instruction to the control portion 40b by the key operation of the operation portion 30. The substrate support frame 14 is given a specific instruction to the control unit 40b by the key operation of the operation unit 30, and can be moved in the ± Z1 direction by the drive of the gantry 10, and can be rotated about a rotation axis 12 parallel to the X1 direction . The laser pointer 20 can be moved to various positions in the ± X1 direction and the ± Z1 direction on the front surface 16a of the stage 16, and can indicate the positions of the front surface 70a and the back surface 70b of the large-scale photomask 70. The position of the laser pointer 20 on the front surface 16a of the stage 16 and the following directions of the laser pointer 20 can be controlled by giving a specific instruction to the control unit 40b by the key operation of the operation unit 30.

The microscope 50 can be moved to various positions of the ± X1 direction and the ± Z1 direction on the front surface 16 a of the stage 16. Therefore, the microscope 50 can be moved to a position to observe each position of the front face 70 a and the back face 70 b of the large-size photomask 70 which are arranged at positions that can be observed by the movement of the gantry 10 and the movement and rotation of the substrate support frame 14.

Next, the operation of the visual inspection device 100 shown in FIG. 1 will be described.
The operation of the appearance inspection device 100 is the first operation in which the observer 200 performs the appearance inspection of the large-size mask 70 in the order of macroscopic observation by visual observation and microscopic observation by detailed observation with a microscope, and the observer 200 Two types of the second action in the case of macro observation using the information of defects obtained by micro observation.

FIG. 2 is a schematic diagram illustrating a first operation of the visual inspection device 100 shown in FIG. 1. FIG. 2 (a) is a diagram schematically showing the laser pointer 20 and the large-sized mask 70 shown in FIG. 1, and FIG. 2 (b) is a diagram schematically showing the microscope 50 and the large-sized mask 70 shown in FIG. Figure. Further, in FIG. 2, the X2 direction refers to a direction parallel to one side of the front surface 70 a of the large-sized mask 70, and the Y2 direction refers to a direction parallel to the front surface 70 a of the large-sized mask 70 and is perpendicular to the X2 direction. The Z2 direction refers to a direction perpendicular to the front surface 70 a of the large-sized mask 70. In FIG. 1, when the angle θx of the front surface 70 a and the back surface 70 b of the large-size mask 70 around the rotation axis 12 from a direction parallel to the floor surface 2 is 0 °, the X2 direction and the Y2 direction in FIG. 2. , And Z2 directions are consistent with the X1 direction, the Y1 direction, and the Z1 direction in FIG. 1.

When the first operation of the visual inspection device 100 shown in FIG. 1 is performed, first, the observer 200 performs a macroscopic observation by visually and globally observing, thereby detecting the front surface 70a of the large-scale photomask 70. Defect 72.
At this time, the macroscopic observation by visual observation can be performed by using the observation illumination fixed as observation illumination 80a to 80c as shown in FIG. 1, but it is preferable that the observer 200 holds the observation illumination as shown in FIG. 7. 80. The observation illumination 80 is irradiated at a specific angle with respect to the front surface 70a of the large-sized mask 70, and is observed while moving left and right, thereby inspecting the defect 72.

Then, as shown in FIG. 1 and FIG. 2 (a), the observer 200 gives a specific instruction to the control unit 40 b by using the key operation of the operation unit 30, and thereby uses the laser pointer 20 of the laser pointer 20 to instruct the large-scale mask 70. Location of defect 72 on front side 70a.

Then, as shown in FIG. 1 and FIG. 2 (a), in a state where the position of the defect 72 is indicated by the laser, the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, thereby, The appearance inspection device 100 obtains the directions (P _θx , P _θy ) of the laser pointer 20 on the front surface 16 a of the stage 16 and the position of the large-size mask 70 by the control unit 40 b, and stores them in the memory unit 40 c.
Here, when the macro observation is performed as shown in FIG. 7, the operation unit 30 is preferably a portable controller that is held by the observer 200 and can perform the above operations on the spot when a defect 72 is found. Type.

Here, the indication directions (P _θx , P _θy ) of the laser pointer 20 refer to an angle of P _θx toward the X2 direction with respect to the reference direction of the Z2 direction as shown in FIG. 2 (a) and toward the Y2 direction. The direction of the angle of inclination P _θy . In addition, the reference direction does not necessarily need to be set to the Z2 direction, for example, it may be set to an arbitrary direction as the Y1 direction in FIG. 1.

Then, the observer 200 gives a specific instruction to the control unit 40 b by using the key operation of the operation unit 30, whereby the appearance inspection device 100 determines the position of the laser pointer 20 and the laser pointer 20 on the front surface 16 a of the stage 16. The geometrical relationship between the indicated directions (P _θx , P _θy ) and the position of the large mask 70, and the two-dimensional coordinates (Mx, My) of the front surface 70a of the large mask 70 indicating the position of the defect 72 are calculated by the control section 40b. And stored in the memory section 40c.

Then, as shown in FIG. 1 and FIG. 2 (b), the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, thereby moving the large-scale photomask 70 to After the substrate supporting frame 14 is moved and rotated to a position where it can be observed, the microscope 50 is moved from the reference position to a position where the front surface 70a of the large-scale mask 70 shown by the two-dimensional coordinates (Mx, My) can be observed. With this, the observer 200 can perform microscopic observation of the defects 72 on the front surface 70 a of the large-size mask 70 using the microscope 50 after adjusting the focus of the microscope 50. Specifically, in FIG. 1, θx is set to 90 °, and the large-size reticle 70 is rotated in the parallel direction of the stage 16 to move the microscope 50 in the two-dimensional direction (Mx, My) of the defect 72.

As described above, in the first operation of the visual inspection device 100, the directions (P _θx , P _θy ) of the laser pointer 20 and the position of the large-size mask 70 are acquired as the large-size mask 70 instructed by visual observation. After visually specifying the defect 72 of the front surface 70a, the two-dimensional coordinates (Mx, My) of the front surface 70a of the large-scale mask 70 can be calculated. As a result, a two-dimensional coordinate (Mx, My) of the front surface 70a of the large-size mask 70 indicating the position of the defect detected by macroscopic observation can be obtained.

Furthermore, for example, when the position of the laser pointer 20 in the front surface 16a of the stage 16 is fixed, as shown in FIG. 1 and FIG. 2 (a), the indication direction of the laser pointer 20 is obtained ( P _θx , P _θy ), and the position of the large reticle 70 determined by the Y1 direction position, the height H, and the rotation angle θx of the pedestal 10, the large reticle representing the position of the defect 72 can be calculated based on the position information The two-dimensional coordinates (Mx, My) of 70a on the front side of 70. The calculation method of the two-dimensional coordinates (Mx, My) indicating the position of the defect 72 is not limited to this method.

FIG. 3 is a schematic diagram showing a second operation of the visual inspection device 100 shown in FIG. 1. FIG. 3 (a) is a diagram showing the large-scale mask 70 shown in FIG. 1, and FIG. 3 (b) is a diagram showing the laser pointer 20 and the large-scale mask 70 shown in FIG. Furthermore, the X2 direction, Y2 direction, and Z2 direction in FIG. 3 are consistent with the X2 direction, Y2 direction, and Z2 direction in FIG. 2.

When the second operation of the visual inspection device 100 shown in FIG. 1 is performed, first, as shown in FIG. 1 and FIG. 3 (a), a large photomask is automatically detected by an visual inspection machine that automatically performs microscopic observation. After defect 74 of front face 70a of 70, defect 74 is corrected. At this time, the two-dimensional coordinates (Mx, My) of the front surface 70a of the large-scale photomask 70 indicating the defect correction portion 74c or the position of the defect 74 on the front surface 70a of the large-scale photomask 70 are documented together with the type of the defect and the like. Then, the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, and thereby, the two-dimensional coordinates (Mx) of the front face 70a of the large-scale mask 70 indicating the correction portion 74c of the defect or the position of the defect 74 , My) is input to the memory section 40c.

In this way, the appearance inspection device of the present invention is provided with a device that not only acquires the two-dimensional coordinates of the main surface of a large photomask indicating the position of a defect detected by macro observation, but also inputs and indicates the defect detected by micro observation. The two-dimensional coordinates of the location of the correction site or defect. This makes it possible to easily perform inspection of defects detected by both macro observation and micro observation.

Then, as shown in FIG. 1 and FIG. 3 (a), according to the setting position of the laser pointer 20 in the front surface 16 a of the stage 16 and the two-dimensional coordinates of the front surface 70 a of the large-scale mask 70 indicating the defect correction portion 74 c. (Mx, My) and the geometric relationship of the position of the large mask 70, the control unit 40b calculates the direction (P _θx , P _θy ) of the laser pointer 20 indicating the correction portion 74c of the defect, and stores it in the memory.部 40c. 40c.

Then, as shown in FIG. 1 and FIG. 3 (b), the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, whereby the visual inspection device 100 uses the direction indicated by the laser pointer 20 ( P _θx , P _θy ) indicates the correction portion 74 c of the defect by using the laser of the laser pointer 20 in a visual manner by the observer 200. Thereby, the observer 200 can visually observe the correction portion 74c of the defect.

As described above, in the second operation of the visual inspection device 100, after the defect 74 of the front surface 70a of the large-size mask 70 detected by microscopic observation is corrected, the defect of the large-size mask 70 of the correction portion 74c showing the defect can be corrected. The two-dimensional coordinates (Mx, My) of the front face 70a calculate the indication direction (P _θx , P _θy ) of the laser pointer 20 indicating the correction portion 74c of the defect as the visually designated information for the correction portion 74c of the defect. Therefore, the correction direction 74c of the defect can be visually indicated using the directions (P _θx , P _θy ) of the laser pointer 20. Thereby, the correction portion 74c of the defect detected by the microscopic observation can be macroscopically observed.

Therefore, according to the present invention, it is possible to obtain the two-dimensional coordinates of the main surface of the large-scale mask representing the position of the defect detected by macroscopic observation. Furthermore, it is possible to visually indicate a defect detected by microscopic observation or a correction portion thereof. This makes it possible to easily perform a defect inspection based on an appearance inspection including both macro observation and micro observation.

1. Visually designated information acquisition device The visually designated information acquisition device described above is a device that obtains visually designated information of the visually designated position of the main surface of the large mask indicated based on visual observation.

As the visually designated information acquisition device, there is no particular limitation. For example, as shown in FIG. 1 and FIG. 2 (a), the defect 74 of the front surface 70a of the large-scale photomask 70 is indicated by the laser of the laser indicator 20 In the state of the position, a specific instruction is given to the control unit 40b, whereby the control unit 40b is used to obtain the position of the laser pointer 20 on the front surface 16a of the stage 16 and the direction ( _Pθx , P _θy ) and the position of the large mask 70.

Here, FIG. 4 is a schematic diagram showing an example of the laser irradiation position of the laser pointer 20 on the front surface 70 a of the large-size mask 70 viewed from the observer 200 shown in FIG. 1. As the above-mentioned visually designated information acquisition device, it may be a device that captures the position of a defect as a point and then designates a point indicated by the laser pointer 20 of the laser pointer. It may also be a device that captures the position of the defect as a rectangular area or a circular area. After the ellipse area, the device of rectangle designation, circle designation, and ellipse designation using the laser pointer of the laser pointer 20 is used to indicate the position of the defect as a straight line. The device designated by the indicated line.

The observer 200 appropriately selects a method for specifying the position of the defect according to the shape and distribution of the defect. The above-mentioned visually designated information acquisition device designated by using the above points indicates the position of the defect as a point to the control section 40b, and obtains the direction ( _Pθx , P) of the laser pointer when the position 411 of the point is indicated as shown in FIG. _θy ). In addition, the visually designated information acquisition device designated by using the rectangle described above indicates to the control unit 40b that the position of the defect is a rectangular area, and acquires lasers at positions 412 and 413 indicating the diagonal positions of the rectangular area as shown in FIG. 4, respectively. Direction of the indicator (P _θx , P _θy ). In addition, the visually designated information acquisition device designated by using the circle described above indicates to the control unit 40b that the position of the defect is a circular area, and obtains the position 414 and the two ends of the center of the diameter of the circular area, as shown in FIG. 4, respectively. The directions of the laser pointers at positions 415 and 416 (P _θx , P _θy ). Furthermore, the device can also obtain the direction (P _θx , P _θx ) of the laser pointer at the two points that indicate only the center position 414 of the diameter of the circular area and the positions 415 and 416 at both ends. P _θy ). In addition, the above-mentioned visually designated information acquisition device designated using an ellipse instructs the control unit 40b to indicate that the position of the defect is an elliptical area, and obtains the position 417 indicating the center of the elliptical area and both ends of the long axis as shown in FIG. The directions of the laser pointer (P _θx , P _θy ) when the positions 418 and 419 of the short axis and the positions 420 and 421 of the two ends of the short axis are sufficient. Furthermore, the device can also obtain one of the position 417 indicating only the center of the elliptical region, one of the positions 418 and 419 of the two ends of the long axis, and one of the positions 420 and 421 of the two ends of the short axis, respectively. Those at 3 o'clock indicate the direction of the laser pointer (P _θx , P _θy ). Further, the above-mentioned visually designated information acquisition device designated using a straight line instructs the control unit 40b to indicate the position of the defect as a straight line, and respectively acquires laser pointers at positions 422 and 423 indicating both ends of the straight line as shown in FIG. 4. _Just indicate the direction (P _θx , P _θy ).

Table 1 shows the visually designated information. The "attribute" indicates the area designation method of the laser pointer 20. “Inclination” indicates the angle θx in FIG. 1, and “indicating direction” indicates the indicating direction of the laser pointer 20.

[Table 1]

As the visually designated information acquisition device, it is not limited to the device using the above method, as long as it can specify the area containing defects in the main surface of the large-scale photomask. The method for specifying the position of the defect is not limited to point designation, rectangle designation, circle designation, ellipse designation, and line designation, as long as the position of the defect can be optimally specified. Furthermore, as the above-mentioned visually designated information acquisition device, it may be a device that obtains the point or straight line visually designated information in the main surface of the large-scale photomask as the above-mentioned visually-designated information, or may be the main surface of the large-scale photomask. A device for visually specifying information of an area having an area, such as a rectangular area, a circular area, or an oval area, but is preferably a device for obtaining the visually specifying information of the area having an area.

2. Visually-designated device The visually-designated device in the present invention is a device that instructs the visually-designated position of the main face of the large-scale photomask that is indicated based on visual observation.

The visual designation device is not particularly limited, and examples thereof include a laser pointer and a pointer in a display image of a touch panel.
As the above-mentioned laser pointer, it is preferable to be arranged above the head of the observer 200 as shown in FIG. 1. The reason is that the large mask 70 does not become an obstacle when the observer 200 visually observes the large mask 70.

Examples of the laser include red light and green light, but red light is preferred. The reason is that it is easy to recognize visually.
In place of the laser pointer, a high-intensity lamp having a diameter of, for example, about 5 mm when irradiated onto the front surface of the large-sized photomask may be used. If the laser pointer is used, visual observation is performed while illuminating the observation illumination. When a defect is found, the brightness in the illuminated area of the observation illumination is high, so it may not be possible to confirm the lightning indicating the defective part. Laser pointer. In this case, by using the high-intensity lamp instead of the laser pointer, the high-intensity lamp is overlapped and irradiated to the vicinity of the defective portion in the irradiation area of the observation illumination capturing the defective portion, and thereafter, After the observation illumination is turned off, the above-mentioned high-intensity lamp is used to identify the defective part and irradiate the position, thereby obtaining position information of the defective part.

Such a high-intensity lamp may also be a person capable of changing the area of the illuminated area on the front side of a large-scale mask. The reason is that the high-intensity lamp is irradiated with the irradiated portion of the above-mentioned observation illumination that catches the defective portion, and then the irradiation area of the high-intensity lamp is reduced to obtain the position information of the defective portion.

Examples of such high-intensity lamps include LSP68x240W-ST (trade name, light source: LED (Light Emitting Diode), color temperature: 6500 K) manufactured by Aitec System Co., Ltd., and PS-NP1 (made by POLARION) Product name, light source: Xenon HID (High-intensity discharge) lamp, color temperature: 4300 K), 370TFI / R (product name, light source: halogen lamp, color temperature: about 3000 K) manufactured by S-vans Co., Ltd. )Wait.
In addition, as the visually designated information acquisition device, it may be a device that illuminates the front side of the large photomask with the observation illumination, and when a defective portion is found, a shadow is generated to indicate the defective portion, and the shadow is specified. Its location.

As a method of generating the shadow, for example, a method including preparing a member having a front end portion such as an indicator rod and inserting it between the above-mentioned observation illumination and the front face of the large-sized mask to generate a shadow indicating the defective portion can be cited. ; Or detachably arrange a filter such as a cross to generate a shadow in the observation lighting, observe it without a filter, and when the defect is found, place the filter in the irradiation portion of the observation lighting. Shadow the defective part.
The location of the shadow can be specified by the following methods: use the laser of the laser pointer to indicate the location of the shadow, use the above method to specify the location; or use the following camera to capture the shadow and The image is analyzed to identify the location.

Furthermore, for example, a light-shielding object may be arranged before the light source for observation illumination, and the irradiation state and non-irradiation state of the irradiation light with respect to the main surface of the large-scale photomask may be alternately repeated, thereby enabling visual designation position.
Specifically, it can be enumerated as follows: using a laser pointer in a non-irradiated state to obtain a visually designated position of a defect on the main surface of a large photomask; or by alternately switching the high-speed irradiation state and the non-irradiated state to make the above When the brightness of the irradiated light on the large photomask is reduced, the laser pointer is used to obtain the visually designated position of the defect on the main surface of the large photomask.
The above-mentioned "high-speed switching" is preferably 70 Hz or more, and more preferably 100 Hz or more.

As a device for realizing the above method, a device capable of rotating a light-shielding object in front of the light source for observation illumination can be cited. When a defective part is found, the light-shielding object is rotated at a low speed, and specifically, the light-shielding object The object is rotated below 1 Hz, and the irradiation and non-irradiation on the front side of the large mask illuminated by observation are repeated, thereby making it easy to detect defects and identify the laser pointer, or to rotate it at high speed to illuminate The reduced surface illumination makes it possible to confirm the position of the laser of the laser pointer.
In addition, it is also possible to repeat the irradiation and non-irradiation on the front side of a large photomask by turning on / off the light source of observation illumination at a low speed when a defective portion is found, or by opening it at high speed. / Turn off to reduce the illuminance on the irradiation surface, and the position of the laser pointer can also be confirmed. In addition, the intensity of the illumination can be repeated at intervals of 0.5 seconds or more, and the intensity of the illuminated surface can be adjusted by adding intensity.

As such a device, the device shown in FIG. 14 and FIG. 15 is mentioned, for example.
The device shown in FIG. 14 (a) includes a light box 1 and a light guide 2 for guiding light from the light box. The light box 1 includes a lamp 3 and a concave mirror 4 that reflects light from the lamp 3, and includes a light shielding plate 5 that can block the light path from the concave mirror 4 and a driving portion 6 that rotates the light shielding plate 5. A control section for adjusting the rotation speed of the light shielding plate 5 is incorporated in the driving section 6. FIG. 14 (b) shows an example of the form of the light-shielding plate 5 described above. The light-shielding plate 5 in this form has a light-shielding area 7 of 270 ° and a light-transmitting area 8 of 90 °. On the other hand, FIG. 14 (c) shows another form of the light-shielding plate 5 having a light-shielding area 7 of 180 ° and a light-transmitting area 8 of 180 °.

The device shown in Fig. 14 can be used in two forms. First, in the case of defects that can be grasped with high-brightness light, first, the light-shielding plate 3 is arranged at a position that does not block light from the light path of the concave mirror 4 and is inspected by light radiated from the front end of the light guide 2 The existence of defects. When a defect is found, the above-mentioned driving part 6 is used to rotate the light-shielding plate 3 at a low speed, and repeatedly irradiate and non-irradiate to the front of the large photomask. In the non-irradiation state, that is, the light-shielding plate 3 When the optical path is blocked, the laser pointer can be used to indicate the defect, so as to identify the position.

On the other hand, when the defect can be visually recognized even if the brightness is reduced, when the defect is found by the light irradiated from the front end of the light guide 2 in the same manner as described above, the light shielding plate 3 can be rotated at a high speed to make the front of the large photomask The brightness is reduced. In this state, the above-mentioned laser pointer is used to indicate a defect, thereby identifying the position.

The device shown in FIG. 15 is provided with a control unit 9 that controls the on / off of the lamp 1 instead of the light shielding plate 5 and the drive unit 6 of the device shown in FIG. 14. In the case of the device shown in FIG. 15, an LED is used as the lamp 1.

The device shown in FIG. 15 can also be used in two forms in the same manner as the device shown in FIG. 14. That is, the case where the opening / closing control is performed at a low speed is a state where the light shielding unit 3 is rotated at a low speed, and the case where the opening / closing control is performed at a high speed is a state where the light shielding unit 3 is rotated at a high speed.

3. Two-dimensional coordinate calculation device The above-mentioned two-dimensional coordinate calculation device is a device that calculates two-dimensional coordinates of the main surface of the large-scale photomask representing the above-mentioned visually specified position according to the above-mentioned visually designated information.

The above-mentioned two-dimensional coordinate calculation device is not particularly limited. For example, the following devices may be cited: the position of the laser pointer 20 in the front surface 16a of the carrier 16 and the pointing direction of the laser pointer 20 (P _θx , P _θy ) and the position of the large reticle 70 as the above-mentioned visually designated information, as shown in FIG. 1 and FIG. 2 (a), a specific instruction is given to the control unit 40 b. The geometrical relationship between the position of the laser pointer 20 in the front face 16a, the direction of the laser pointer 20 (P _θx , P _θy ), and the position of the large mask 70 is calculated by the control unit 40 b. In addition, for example, a large photomask can be photographed, and a two-dimensional coordinate of a defect indicated by the touch panel is calculated based on a mark such as an alignment mark on the main surface of the large photomask.

FIG. 11 is a structural diagram of obtaining two-dimensional coordinates using a touch panel. Use a camera to take a photo of the photomask. Based on the coordinates of the alignment marks on the photomask and the position of the alignment marks on the image data, find the light corresponding to the defect position (x, y) touched by the observer on the display. The two-dimensional coordinates (Mx, My) on the mask.

In addition, if the visual designation information indicates a position of a point in the main surface 70a of the large-size photomask 70 shown in FIG. 4, the two-dimensional coordinate calculation device only needs to calculate a two-dimensional coordinate indicating the point. In addition, if the above-mentioned visually designated information indicates a position of an area having an area such as a rectangular area, a circular area, or an elliptical area in the main surface 70a of the large mask 70 shown in FIG. The coordinate calculation device only needs to calculate the two-dimensional coordinates such as the diagonal positions of the rectangular area, the two-dimensional coordinates of the center position and the two ends of the diameter of the circular area, the central position of the ellipse area, and the long axis, respectively. A plurality of two-dimensional coordinates, such as the two-dimensional coordinates of the positions of the two ends of the short axis and the two ends of the positions of the short axis.

4. Microscope The microscope can be moved to a position where each position of the main surface of the large-scale mask can be observed.

The microscope is not particularly limited, but it is preferably one or two or more functions having a size measurement function for measuring a size, a transmittance measurement function for measuring transmittance, and a reflectance measurement function for measuring reflectance.

5. Microscope driving device The microscope driving device is a device that moves the microscope to a position where the main surface of the large photomask shown in the two-dimensional coordinates can be observed.

The microscope driving device is not particularly limited, and examples thereof include a stage 16 that can be drivably disposed in the appearance inspection device like the stage 16 shown in FIG. 1 and that can hold the stage of the microscope and is provided to the control unit 40b. The specific instruction moves the microscope 50 to a stage or the like where the position of the main surface of the large-scale photomask 70 indicated by the two-dimensional coordinates can be observed. In addition, as the microscope driving device, as long as the stage 16 and the gantry 10 and the substrate supporting frame 14 shown in FIG. 1 are used, the microscope is moved to a position where the relative position of the microscope and the large photomask is moved. It is sufficient to observe the device at the position of the main surface of the large photomask shown by the two-dimensional coordinates. Therefore, the microscope driving device may be a device including a device that moves the large photomask to the microscope side.

The microscope driving device may be a device that moves the microscope to the above-observable position by giving an instruction to the control unit to move the microscope by manually inputting a moving direction and a moving distance, or may be a control The device is provided with an instruction to automatically move the microscope to the observable position and a device to automatically move the microscope to the observable position, but is preferably a device to automatically move the microscope to the observable position. .

6. Two-dimensional coordinate input device The two-dimensional coordinate input device described above is a device that inputs two-dimensional coordinates representing an arbitrary position of the main surface of the large-scale photomask.

As the two-dimensional coordinate input device, for example, as shown in FIG. 1 and FIG. 3 (a), a large mask 70 that gives a correction portion 74c indicating a defect by the control portion 40b by giving a specific instruction to the control portion 40b may be cited. The two-dimensional coordinates (Mx, My) of the front surface 70a are input to a device or the like of the memory portion 40c.

7. Other Other features of the visual inspection device of the present invention will be described in detail.

(1) Visually designated information computing device The visual inspection device described above is preferably a person who has a visually designated information computing device, and the visually designated information computing device is used to visually calculate the two-dimensional coordinate input based on the two-dimensional coordinate input device described above. Visually specify information at any of the above locations.

The visually designated information calculation device is not particularly limited as long as it is a person who calculates the visually designated information of the laser pointer 20. For example, as shown in FIG. 1 and FIG. 3 (a), according to the position of the laser pointer 20 in the front surface 16a of the stage 16, the two-dimensional coordinates of the front surface 70a of the large-scale mask 70 indicating the defect correction portion 74c ( Mx, My) and the geometrical relationship of the position of the large reticle 70, the control unit 40b calculates the direction (P _θx , P _θy ) of the laser pointer 20 that visually indicates the correction portion 74c of the defect.

FIG. 12 shows a process of calculating visual designation information based on an arbitrary two-dimensional coordinate (Mx, My) on the reticle. Input arbitrary two-dimensional coordinates (Mx, My) into the memory section 40c (step 1), and calculate the visually designated information (P _θx , P _θy ) of the laser pointer 20 based on the two-dimensional coordinates (Mx, My) (step 2) ).

FIG. 13 shows a process of calculating visually designated information using a touch panel. The large reticle is photographed, and the defect displayed on the display is designated by the touch panel, and the defect position (x, y) is obtained (step 1). Marks such as alignment marks of the photographed mask are extracted (step 2). The defect position (Mx, My) on the mask is calculated based on marks such as alignment marks, and the visually designated information (P _θx , P _θy ) is obtained (step 3).

(2) Illumination for Observation The above-mentioned appearance inspection device usually further includes observation illumination for visual observation.

As the above-mentioned observation illumination, for example, a plurality of observation illuminations having different types of light sources of the observation illuminations 80a to 80c shown in FIG. 1 are preferable. The reason is that by using such a plurality of observation illuminations, it is easy to detect various defects (unevenness, spots, dirt, scars, foreign matter, etc.) in visual observation. Examples of the type of the light source include fluorescent lamps, high-intensity halogen projectors, high-intensity LEDs, HID (POLARION), and Na lamps. Furthermore, if a light source obtained by combining a short-wavelength cut filter with a Na lamp is used as a light source, the coating unevenness inspection can also be performed. In addition, as the above-mentioned observation lighting, a fixed type may be used, or a type that allows an observer to move freely while holding it.

(3) Rotating mechanism The visual inspection device usually further includes a rotating mechanism that rotates the large photomask around a rotation axis parallel to the main surface of the large photomask.

The appearance inspection device 100 shown in FIG. 1 includes a rotation shaft 12 fixed to a stand 10 provided on the floor surface 2, and a substrate support frame 14 fixed to the stand 10 via the rotation shaft 12 and rotatable about the rotation shaft 12. The rotation mechanism can rotate the large-sized photomask 70 provided on the substrate support frame 14 about a rotation axis 12 parallel to the front surface 70 a of the large-sized photomask 70.

As the rotation mechanism, it is preferable that the angle of rotation of the main surface of the large-scale mask around the rotation axis from a direction parallel to the floor surface is 90 ° or more. The reason is that, for example, as shown in FIG. 1, the angle θx of the front surface 70 a of the large-scale mask 70 rotating about the rotation axis 12 from a direction parallel to the floor surface 2 is 90 ° or more, so that the large-scale light In a state where the front surface 70a of the cover 70 is inclined in a direction perpendicular to the floor surface 2, the observer 200 can perform visual observation of the front surface 70a, and therefore, visual observation of the front surface 70a becomes easy. Among them, the above-mentioned rotatable angle is preferably 270 ° or more. The reason is that, for example, the observer 200 can perform the back surface 70b in a state where the back surface 70b of the large-size mask 70 is tilted in a direction perpendicular to the floor surface 2 by the angle θx shown in FIG. 1 being 270 ° or more. Visual observation makes it easy to visually observe the back surface 70b.

(4) An imaging device As the appearance inspection device, it is preferable that the imaging device further includes an imaging device that photographs a main surface of the large-scale photomask.

For example, the appearance inspection apparatus 100 shown in FIG. 1 includes a digital camera 90 that photographs the front surface 70 a or the back surface 70 b of a large-sized mask 70. Thereby, for a person other than the observer 200 who directly observes the front surface 70 a or the back surface 70 b of the large-size mask 70, the control portion 40 b can display the image captured by the digital camera 90 on the display portion 40 a. The reason for this is that the state of the main surface of the large photomask can be made known. Furthermore, by displaying the captured image on a touch panel, the display image of the touch panel can be used in the two-dimensional coordinate calculation device, the visual designation information calculation device, and the visual designation device. In addition, as the imaging device, for example, in addition to a digital camera, a TV (television) camera or the like may be mentioned.

In addition, as the imaging device, a digital camera 90 as shown in FIG. 1 is preferably arranged above the head of the observer 200. The reason is that the large mask 70 does not become an obstacle when the observer 200 visually observes the large mask 70.

(5) Other above-mentioned visual inspection devices generally include control devices such as the control unit 40b shown in FIG. 1 that control the components, devices, and mechanisms of the visual inspection device. In addition, the appearance inspection device may include an operation device such as the operation unit 40b shown in FIG. 1 that gives a specific instruction to the control device from the outside in order to control the constituent elements.

In addition, the appearance inspection device usually has two-dimensional coordinates that memorize the visual designation information, a main surface of the large photomask indicating the visually designated position, a two-dimensional coordinate indicating an arbitrary position of the main surface of the large photomask, and the above. The memory device of the memory portion 40c shown in FIG. 1 is any one or two or more types of information for visual position information.

In addition, the above-mentioned appearance inspection apparatus usually includes a display device of a display section 40a as shown in FIG. Examples of the display device include a liquid crystal display and an organic EL (Electroluminescence) display. The display device can also be used as a touch panel used in the visual designation information acquisition device described in the item of "1. Visual designation information acquisition device".

Furthermore, the appearance inspection device may further include an input device for externally inputting a two-dimensional coordinate representing an arbitrary position of the main surface of the large photomask, and the microscope driving device may move the microscope to be able to observe the input using the input device. The position of the main surface of the large photomask shown by the two-dimensional coordinates. Thus, for example, a two-dimensional coordinate representing the position of a defect on the main surface of a large photomask automatically acquired by a microscopic appearance inspection machine that automatically performs microscopic observation can be inputted from the microscopic appearance inspection machine to the above-mentioned appearance inspection device, and then The microscope is moved to a position where the principal surface indicated by the two-dimensional coordinates can be observed, thereby observing the defect in detail. In addition, after inputting the two-dimensional coordinates indicating the positions of the alignment marks or various marks such as the product name recorded on the main surface of the large-scale mask to the above-mentioned appearance inspection device from outside, the microscope can be moved to the place where the two-dimensional coordinates can be observed. The position of the above-mentioned main surface is shown so that various marks can be observed in detail.

B. Appearance inspection method The appearance inspection method of the present invention is roughly divided into the first aspect used when the appearance inspection of a large photomask is performed in the order of macro observation and micro observation, and the order of micro observation and macro observation. The second aspect is used for the appearance inspection of a large photomask.

I. The first aspect The appearance inspection method of the first aspect is characterized by having: a step of obtaining visually designated information, which is to obtain the visually designated information of the defect of the main surface of the large mask indicated based on visual observation; two-dimensional coordinates The calculation step is to calculate the two-dimensional coordinates of the main surface of the large-scale photomask indicating the position of the defect according to the visual designation information; and the microscopic observation step is to observe the large-scale photomask shown by the two-dimensional coordinate with a microscope. Position of the main face.

An example of the appearance inspection method of the first aspect will be described with reference to the drawings. FIG. 5 is a flowchart showing an example of the appearance inspection method of the first aspect.

In the visual inspection method of this example, first, step S11 of obtaining visual designated information is performed as shown in FIG. 5. For example, first, as shown in FIG. 1, the observer 200 performs a macroscopic observation by observing the whole with visual observation, thereby detecting a defect 72 on the front surface 70 a of the large-scale mask 70. Next, as shown in FIG. 1 and FIG. 2 (a), the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, and thereby instructs the large-scale photomask by using the laser of the laser pointer 20. The position of the defect 72 on the front side 70a of 70. Then, as shown in FIG. 1 and FIG. 2 (a), in a state where the position of the defect 72 is indicated by the laser, the observer 200 gives a specific instruction to the control unit 40 b by using the key operation of the operation unit 30. The appearance inspection device 100 obtains the directions (P _θx , P _θy ) of the laser pointer 20 on the front surface 16 a of the stage 16 and the position of the large-size photomask 70 by the control unit 40 b, and stores them in the memory unit 40 c.

Then, a two-dimensional coordinate calculation step S12 is performed as shown in FIG. 5. For example, as shown in FIG. 1 and FIG. 2 (a), the observer 200 gives a specific instruction to the control section 40 b by using the key operation of the operation section 30, whereby the appearance inspection device 100 performs a lightning operation on the front surface 16 a of the stage 16. The geometrical relationship between the position of the laser pointer 20, the direction of the laser pointer 20 (P _θx , P _θy ), and the position of the large photomask 70 is calculated by the control unit 40 b. The two-dimensional coordinates (Mx, My) of the front face 70a of 70 are stored in the memory portion 40c.

Then, a microscopic observation step S13 is performed as shown in FIG. 5. For example, as shown in FIG. 1 and FIG. 2 (b), the observer 200 gives a specific instruction to the control section 40b by using the key operation of the operation section 30, thereby, by moving the gantry 10 and the substrate support frame 14 and After rotating the large mask 70 to a position where it can be observed with the microscope 50, the microscope 50 is moved from the reference position to a position where the front surface 70a of the large mask 70 shown by the two-dimensional coordinates (Mx, My) can be observed. position. Next, after the observer 200 adjusts the focus of the microscope 50, a microscopic observation of the defect 72 of the front surface 70a of the large-size mask 70 by the microscope 50 is performed.

As described above, in the visual inspection method of this example, the indication direction (P _θx , P _θy ) of the laser pointer 20 indicating the position of the defect 72 in the front surface 16 a of the stage 16 and the large photomask 70 are acquired. After visually specifying the position of the defect 72 on the front surface 70a of the large mask 70 indicated based on visual observation, the front surface 70a bis of the large mask 70 indicating the position of the defect 72 can be calculated based on the visual designation information of the defect 72. Dimensional coordinates (Mx, My).

Therefore, according to the first aspect, the two-dimensional coordinates of the main surface of the large mask representing the position of the defect detected by macro observation can be obtained, and therefore, it is easy to microscopically observe the defect detected by macro observation.

1. Steps of Obtaining Visual Designation Information In the above-mentioned step of obtaining visual designation information, obtain visual designation information of defects on the main surface of the large mask indicated based on visual observation.

The method for obtaining the above-mentioned visually designated information is not particularly limited. For example, the method for obtaining the above-mentioned visually designated information using the visually designated information acquisition device described in the item "A. Visual inspection device 1. Visually designated information acquisition device" mentioned above can be listed. Method, etc. The visual designation information is not particularly limited, and examples thereof include visual designation information described in the item "A. Appearance Inspection Device 1. Visual Designation Information Acquisition Device".

2. Two-dimensional coordinate calculation step In the above-mentioned two-dimensional coordinate calculation step, the two-dimensional coordinates of the main surface of the large photomask representing the position of the defect are calculated according to the visually designated information.

The method for calculating the two-dimensional coordinates is not particularly limited. For example, a method for calculating the two-dimensional coordinates using the two-dimensional coordinate calculation device described in the item "A. Appearance inspection device 2. Two-dimensional coordinate calculation device" may be mentioned. Wait.

3. Microscopic observation step In the above microscopic observation step, the position of the main surface of the large photomask shown by the two-dimensional coordinates is observed with a microscope.

The microscope is not particularly limited. For example, as shown in FIG. 1, the microscope described in the item “A. Appearance Inspection Device 3. Microscope” may be mentioned.

4. Appearance Inspection Method The appearance inspection method of the first aspect is generally implemented using the appearance inspection device described in the item of "A. Appearance Inspection Device" above.

5. In the appearance inspection method of the first aspect, there is usually a defect inspection step in which a defect is found by observation of the appearance before the above visually designated information acquisition step. The above-mentioned visually designated information acquisition step is performed on the defects found through the above-mentioned defect inspection steps.
This defect inspection step is not particularly limited, and is usually performed as follows, as shown in FIG. 7, the observer 200 holds the observation illumination 80 and, with respect to the front surface 70 a of the large-size mask 70, the observation illumination 80 A specific angle is irradiated at an oblique angle, and observation is performed while moving up, down, left, and right, thereby inspecting the defect 72.
The defect inspection step in this aspect is not particularly limited, and it is preferable to use the following "C. Defect inspection method".

II. The second aspect The appearance inspection method of the second aspect is characterized by: a defect correction step that corrects a defect on the main surface of a large photomask; and a visually designated information calculation step that is based on the correction portion indicating the above defect. The two-dimensional coordinates of the main surface of the large mask are used to calculate the visual designation information of the correction part of the defect; and a macro observation step is to use the visual designation information to indicate the correction position of the defect, thereby correcting the defect. Visual observation of the site.

An example of the appearance inspection method of the second aspect will be described with reference to the drawings. FIG. 6 is a flowchart showing an example of a visual inspection method of the second aspect.

In the visual inspection method of this example, first, a defect correction step S21 is performed as shown in FIG. 6. For example, first, as shown in FIG. 1, a defect 74 on the front surface 70 a of the large-size mask 70 is automatically detected by an external inspection machine that automatically performs microscopic observation, and then the defect 74 is corrected. At this time, the two-dimensional coordinates (Mx, My) of the front surface 70a of the large photomask 70 indicating the defect correction portion 74c or the position of the defect 74 on the front surface 70a of the large photomask 70 are documented together with the type of the defect and the like.

Next, as shown in FIG. 6, a visual designation information calculation step S22 is performed. For example, as shown in FIG. 1 and FIG. 3 (a), the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, thereby increasing the size of the correction portion 74c or the position of the defect 74, which indicates the defect. The two-dimensional coordinates (Mx, My) of the front surface 70a of the mask 70 are input to the memory portion 40c. Then, the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, and thereby, according to the position of the laser pointer 20 in the front surface 16a of the stage 16, the large light of the correction portion 74c indicating the defect The geometrical relationship between the two-dimensional coordinates (Mx, My) of the front face 70a of the mask 70 and the position of the large mask 70 is calculated by the control section 40b. The direction of the laser pointer 20 (P _θx , P _θy ) and are stored in the memory portion 40c.

Then, a macro observation step S23 is performed as shown in FIG. 6. For example, as shown in FIG. 1 and FIG. 3 (b), the observer 200 gives a specific instruction to the control unit 40b by using the key operation of the operation unit 30, whereby the visual inspection device 100 uses the direction indicated by the laser pointer 20 ( P _θx , P _θy ), using the laser of the laser pointer 20 to indicate the correction portion 74 c of the defect in a manner that can be visually observed by the observer 200. Then, the observer 200 visually observes the correction portion 74c of the defect indicated by the laser.

As described above, in the visual inspection method of this example, after the defect 74 of the front surface 70a of the large-size mask 70 detected by microscopic observation is corrected, the defect of the large-size mask 70 of the correction portion 74c indicating the defect can be corrected. The two-dimensional coordinate (Mx, My) of the front 70a calculates the direction (P _θx , P _θy ) of the laser pointer 20 indicating the correction portion 74c indicating the defect as the visual observation of the correction portion 74c indicating the defect visually. Targeting information. Therefore, the direction (P _θx , P _θy ) of the laser pointer 20 can be used to visually indicate the correction portion 74 c of the defect. Thereby, the correction portion 74c of the defect detected by the microscopic observation can be macroscopically observed.

Therefore, according to the second aspect, it is possible to visually indicate a defect or a correction portion thereof detected by microscopic observation, and therefore, it is easy to observe the defect or the correction portion macroscopically.

1. Defect Correction Step In the above defect correction step, the defects on the main surface of the large photomask are corrected.

The method for correcting the above-mentioned defects is not particularly limited, but in the case where the above-mentioned defects are black defects, for example, the black particles may be irradiated with a charged particle beam while the auxiliary gas is supplied to the black defects to etch the black defects Method, etc. When the defect is a white defect, for example, a method of irradiating a charged particle beam while supplying the deposition gas to the white defect to accumulate a correction film may be mentioned.

Furthermore, in the present invention, the so-called black defect refers to an unnecessary unnecessary portion in a mask pattern of a large photomask. The white defect is a defect in a mask pattern of a large mask.

2. Calculation step of visual designation information In the above calculation step of visual designation information, the two-dimensional coordinates of the main surface of the large photomask representing the correction portion of the defect are calculated to indicate the correction portion of the defect in a visual manner. Visually specify information.

The method for calculating the above-mentioned visually designated information is not particularly limited. For example, examples of the method include the visual position described in the item "A. Appearance inspection device 6. Other (1) Visually designated information calculation device and visually designated device". The information calculation device calculates the above-mentioned visual position information.

3. Macroscopic observation step In the above macroscopic observation step, a visual observation of the correction portion of the defect is performed by using the visual designation information to indicate the correction portion of the defect.

The method of using the visually designated information to indicate the above-mentioned defect correction location is not particularly limited, and examples thereof include the above-mentioned "A. Appearance inspection device 6. Other (1) Visually designated information calculation device and visually designated device" The method of visually designating the designated device to indicate the above-mentioned defect correction part is described.

4. Appearance Inspection Method The appearance inspection method of the second aspect is generally implemented using the appearance inspection device described in the item "A. Appearance Inspection Device" above.

III. Other Aspects As other aspects of the appearance inspection method of the present invention, the following methods can be enumerated: a defect representing the front side of a large photomask that is automatically acquired by a microscopic appearance inspection machine that automatically performs microscopic observation; The two-dimensional coordinates of the position are inputted from the microscopic appearance inspection machine to the appearance inspection device described in the item "A. Appearance inspection device", and then the microscope in the above-mentioned appearance inspection device is moved to observe the above-mentioned two-dimensional coordinates The position of the main surface of the large photomask was used to observe the defect in detail.

C. Defect inspection method The defect inspection method of the present invention is characterized in that the main surface of the large photomask is irradiated with observation illumination at a fixed irradiation angle, and an irradiation area is provided on the main surface of the large photomask. The whole area of the main surface of the large photomask is checked by moving the irradiation area up, down, left and right, so as to check whether there are defects existing in the main surface of the large photomask, and the whole surface inspection is to change the observation. The illumination is performed at least twice with respect to the irradiation angle of the main surface of the large-scale mask.

Examples of defects existing on the main surface of the large-scale photomask, that is, the front surface, include so-called uneven areas, spots, dirt, and foreign matter that are different from the surroundings. Furthermore, the patterns formed on the large-size photomask are listed. The edge of the bad. These defects are difficult to find in ordinary visual inspections. Therefore, since previously, for example, inspection methods using observation lighting as shown in FIG. 7 have been performed.
That is, as shown in FIG. 7, the observer 200 holds the observation illumination 80 and inclines the observation illumination 80 at a specific angle with respect to the front surface 70 a of the large-size mask 70 to illuminate the observation illumination 80. The moving side is observed to inspect the defect 72.

However, the current situation is that even in the case of inspection by the above-mentioned method, there may be omissions of defects, which cannot be fully satisfied as the reliability of the inspection.
The present inventors conducted diligent research in order to solve the above-mentioned problems, and found that there are cases where the discoverable defects are different depending on the angle of the observation illumination with respect to the main surface of the large photomask. By using the above-mentioned defect inspection method, the effect of greatly reducing omissions in defect inspection of a large mask can be exhibited.
Hereinafter, the defect inspection method of the present invention will be described in detail.

1. Irradiation angle The present invention is characterized in that, when inspecting a defect of a large photomask, the angle of irradiation of the observation illumination with respect to the main surface of the large photomask is changed at least twice. The reason for reducing the number of missed defects by performing the irradiation angle change at least twice is estimated as follows.
That is, according to research by the inventors, the possibility that a foreign object that is one of the above-mentioned defects or the edge of a pattern formed on a large mask is equal to the above-mentioned can be found when the irradiation angle is small. On the other hand, the unevenness, spots, and dirt are more likely to be detected when the irradiation angle is increased and the illuminance of the irradiation area is somewhat high. Furthermore, the unevenness can be found at different angles depending on the type, and there is a possibility that the inspection may be overlooked at one angle. In terms of the above, as described above, by performing the entire surface inspection at least twice or more by changing the angle, it is possible to reduce the omission of defects.

Specifically, as shown in FIG. 8, a low-irradiation-angle whole-surface inspection is performed at a low-irradiation angle A with a small irradiation angle A where the irradiation angle of the observation illumination 80 with respect to the main surface of the large mask 70 is small, and an observation is performed. The entire surface inspection is performed at a high irradiation angle B with a high irradiation angle B where the illumination angle of the illumination 80 with respect to the main surface of the large-scale mask 70 is large.
Here, the irradiation angle A in the whole inspection of the low irradiation angle is centered on 30 °, preferably in a range of 15 ° to 45 °, and preferably in a range of 20 ° to 40 °, particularly preferably 25. Within the range of ° ~ 35 °.

On the other hand, the irradiation angle B in the entire inspection of the high irradiation angle is centered on 60 °, preferably in a range of 45 ° to 75 °, and preferably in a range of 50 ° to 70 °, particularly preferably 55 ° to 65 °.
In the present invention, as described above, the angle of the whole-surface inspection may be changed to perform at least two whole-surface inspections. Therefore, the whole-surface inspection may be performed more than three times.

In addition, the irradiation angle in each of the entire surface inspections is preferably fixed, and is preferably performed within a range of at least ± 10 °, and more preferably ± 5 °.

2. Whole-surface inspection The whole-surface inspection in the present invention is not particularly limited as long as it is a method capable of inspecting the entire surface of the large-scale mask, but the above-mentioned entire-surface inspection is preferably performed by repeating the following steps to inspect the large-scale mask Inspection of the entire surface and the entire surface, that is, illuminating the observation illumination from a side of one of the large photomasks in a direction orthogonal to the one side, and inspecting one side while moving the side parallel to the one side. After the amount of length, the irradiation area is moved at a specific distance in a direction orthogonal to the one side.

That is, as shown in FIG. 9, the observation illumination 80 is irradiated from one side 71 side of the large-scale mask 70 in a direction orthogonal to the one side 71 to form an irradiation area 81. Then, the inspection illumination 80 is moved in parallel to the one side 71 while the irradiation area 81 is moved in the direction P parallel to the one side 71. After checking the length of the one side 71, the irradiation area 81 is moved by a specific distance in the direction R orthogonal to the one side 71. By repeating this operation, the entire surface of the large-size mask 70 can be inspected. In addition, the entire surface inspection by this method is set as the side entire surface inspection.

When the irradiation area is moved in the direction r orthogonal to the above-mentioned one side 71, it is preferable to move the irradiation area so as to overlap by about 20 mm from the viewpoint of preventing the defect from being missed.
In the present invention, it is preferable to perform the above-mentioned side entire surface inspection on two orthogonal sides, and it is particularly preferable to perform the above-mentioned side entire surface inspection on all four sides as shown in FIG. 10.
The reason is that, depending on the direction of the pattern drawn on the large photomask, there is a possibility that the defect may be overlooked in the entire surface inspection of only one side.

In the above-mentioned full-surface inspections, as described above, at least two full-surface inspections are performed by changing the angle. Therefore, at least eight full-surface inspections are performed when all four sides are subjected to full-surface inspections, which should be performed at least eight times. The entire inspection is best from the viewpoint of minimizing the omission of defects.

3. Movement speed of the irradiation area The movement speed of the irradiation area irradiated by the above-mentioned observation illumination is preferably 5 cm / second to 9 cm / second, of which 6 cm / second to 8 cm / second is preferable, and 7 is particularly preferable. cm / s. The reason is that in the case where the speed is faster than the above range, the possibility of missing the defect becomes higher, and the reason is that in the case where the speed is slower than the above range, when the uneven defect is found, the intensity of the reflected light changes. It becomes gentle, making it difficult to make uneven judgments.

4. Other items mentioned in "C. Defect inspection method", such as the type of illumination for observation or the fixing method of large photomasks, can be used in the description of "A. Visual inspection device" and "B. Visual inspection method" By.
D. Manufacturing method of large photomask The manufacturing method of large photomask of the present invention is characterized by having an inspection step using the above-mentioned "B. appearance inspection method" or "C. defect inspection method".
The large photomask in the present invention is, for example, a user in a photolithography process at the time of manufacturing a flat panel display or a color filter, and more specifically, in an exposure process.

The manufacturing method of the large-scale photomask of the present invention is characterized in that: in the appearance inspection step, there is an inspection step using the above-mentioned appearance inspection method or defect inspection method, and the other steps are the same as the previously performed steps, so the description here is omitted. .

The present invention is not limited to the embodiments described above. The above-mentioned embodiment is exemplified, and those having substantially the same configuration and exhibiting the same effect as the technical idea described in the patent application scope of the present invention are included in the technical scope of the present invention.

1‧‧‧ Lightbox

2‧‧‧ floor

3‧‧‧ Shading plate

4‧‧‧ concave mirror

5‧‧‧base / shading plate

6‧‧‧Driver

7‧‧‧ shading area

8‧‧‧ Translucent area

9‧‧‧ Control Department

10‧‧‧stand

12‧‧‧rotation axis

14‧‧‧ substrate support frame

14a‧‧‧ opening

16‧‧‧ carrier

16a‧‧‧front

20‧‧‧laser indicator

30‧‧‧Operation Department

40‧‧‧Computer

40a‧‧‧Display

40b‧‧‧Control Department

40c‧‧‧Memory Department

50‧‧‧ microscope

70‧‧‧large photomask

70a‧‧‧front

70b‧‧‧ back

71‧‧‧ side

72‧‧‧ defects

74‧‧‧ defects

74c‧‧‧ Correction

80‧‧‧observation lighting

80a‧‧‧observation lighting

80b‧‧‧observation lighting

80c‧‧‧observation lighting

81‧‧‧ Irradiated area

90‧‧‧ digital camera

100‧‧‧Appearance inspection device

100‧‧‧Appearance inspection device

200‧‧‧ Observer

411‧‧‧Laser indicator irradiation position

412‧‧‧Laser indicator irradiation position

413‧‧‧Laser indicator irradiation position

414‧‧‧Laser indicator irradiation position

415‧‧‧Laser indicator irradiation position

416‧‧‧Laser indicator irradiation position

417‧‧‧Laser indicator irradiation position

418‧‧‧Laser indicator irradiation position

419‧‧‧Laser indicator irradiation position

420‧‧‧Laser indicator irradiation position

421‧‧‧Laser indicator irradiation position

422‧‧‧Laser indicator irradiation position

423‧‧‧Laser indicator irradiation position

A‧‧‧low irradiation angle

B‧‧‧High Irradiation Angle

H‧‧‧ height

P‧‧‧direction

P _{θ x} ‧‧‧ angle

P _{θ y} ‧‧‧ angle

R‧‧‧ direction

S11‧‧‧ Steps to Obtain Visually Specified Information

S12‧‧‧Two-dimensional coordinate calculation steps

S13‧‧‧Micro observation steps

S21‧‧‧ Defect Correction Procedure

S22‧‧‧Calculation steps of visual specified information

S23‧‧‧Macro observation steps

X1‧‧‧ direction

Y1‧‧‧ direction

Z1‧‧‧ direction

X2‧‧‧ direction

Y2‧‧‧ direction

Z2‧‧‧ direction

θx‧‧‧rotation angle

FIG. 1 is a schematic side view showing an example of an appearance inspection apparatus of the present invention.

2 (a) and 2 (b) are schematic diagrams illustrating the first operation of the visual inspection device shown in FIG.

3 (a) and 3 (b) are schematic diagrams showing a second operation of the visual inspection device shown in FIG. 1.

FIG. 4 is a schematic view showing a large reticle as viewed from the viewer shown in FIG. 1. FIG.

FIG. 5 is a flowchart showing an example of the appearance inspection method of the first aspect.

FIG. 6 is a flowchart showing an example of a visual inspection method of the second aspect.

FIG. 7 is an explanatory diagram for explaining a defect inspection method.

FIG. 8 is an explanatory diagram showing an example of a defect inspection method of the present invention.

FIG. 9 is an explanatory diagram showing an example of a defect inspection method of the present invention.

FIG. 10 is an explanatory diagram showing an example of a defect inspection method of the present invention.

FIG. 11 is an explanatory diagram for explaining an example of an appearance inspection device of the present invention.

Fig. 12 is a flowchart showing an example of an appearance inspection apparatus of the present invention.

Fig. 13 is a flowchart showing an example of an appearance inspection apparatus of the present invention.

14 (a) to 14 (c) are explanatory diagrams showing an example of a light source for finding defects in the visual inspection device of the present invention.

FIG. 15 is an explanatory view showing another example of a light source for detecting defects in the visual inspection device of the present invention.

Claims (19)

An appearance inspection device, comprising: The visually designated device, which indicates the visually designated position of the main face of the large photomask, which is indicated based on visual observation; Visually designated information acquisition device, which obtains visually designated information; A two-dimensional coordinate calculation device that calculates a two-dimensional coordinate of a main surface of the large photomask representing the visually designated position according to the visually designated information; A microscope, which can be moved to a position capable of observing various positions of the main surface of the large photomask; A microscope driving device that moves the microscope to a position where the main surface of the large photomask shown by the two-dimensional coordinates can be observed; and The two-dimensional coordinate input device inputs a two-dimensional coordinate representing an arbitrary position of a main surface of the large-scale photomask. For example, the visual inspection device of claim 1 is provided with a visual information calculation device that calculates the visual designation information based on the two-dimensional coordinates input through the two-dimensional coordinate input device. For example, the visual inspection device according to claim 1, wherein the visual designation information acquiring means acquires the visual designation information indicating an area having an area. The appearance inspection device according to claim 1, further comprising a plurality of observation illuminations having different types of light sources. The visual inspection device according to any one of claims 1 to 4, further comprising a rotation mechanism that rotates the large-sized photomask around a rotation axis parallel to the main surface of the large-sized photomask, and enables the large-sized photomask to rotate. The angle of rotation of the main surface of the mask around the rotation axis from a direction parallel to the floor surface is 90 ° or more. The visual inspection device according to claim 5, wherein the rotatable angle is 270 ° or more. The visual inspection device according to claim 1, further comprising an imaging device for imaging a main surface of the large-scale photomask. An appearance inspection method, comprising: The step of obtaining visually designated information is to obtain the visually designated information of the defect of the main surface of the large mask indicated based on visual observation; The two-dimensional coordinate calculation step is to calculate the two-dimensional coordinates of the main surface of the large photomask representing the position of the defect according to the visually designated information; and The microscopic observation step is to observe the position of the main surface of the large photomask shown by the two-dimensional coordinates with a microscope. The visual inspection method of claim 8, wherein The above visually designated information acquisition step is performed in the defect inspection step of inspecting the presence or absence of defects existing on the main surface of the large-scale photomask by observing the appearance, The above defect inspection steps are The main surface of the large photomask is irradiated with observation illumination at a fixed irradiation angle, and an irradiation area is provided on the main surface of the large photomask. The main of the large photomask is inspected by moving the illuminated area up, down, left, and right. Inspection of the entire surface, and The entire surface inspection is performed at least twice by changing the irradiation angle of the observation illumination with respect to the main surface of the large-scale mask. An appearance inspection method, comprising: Defect correction step, which is to correct the defect of the main surface of the large photomask; The step of calculating the visually designated information is to calculate the visually designated information based on the two-dimensional coordinates of the main surface of the large-scale mask representing the correction portion of the defect; and The macro observation step is to visually observe the corrected part of the defect according to the visually designated information. A defect inspection method characterized in that the main surface of a large photomask is irradiated with observation illumination at a fixed irradiation angle, and an irradiation area is provided on the main surface of the large photomask, and the above-mentioned irradiated area is up and down and left and right Move to perform a full-surface inspection that inspects the entire surface of the main surface of the large-scale photomask, thereby inspecting the presence or absence of defects in the main surface of the large-scale photomask, and The entire surface inspection is performed at least twice by changing the irradiation angle of the observation illumination with respect to the main surface of the large-scale mask. The defect inspection method according to claim 11, wherein the entire surface inspection includes a low-irradiation angle entire surface inspection performed at an angle in the range of 15 ° to 45 °, and the irradiation angle is 45 ° to 75 °. The whole surface is inspected at a high irradiation angle at an angle within the range. For example, the defect inspection method of claim 11, wherein the entire surface inspection is an inspection of the entire surface of the large photomask by repeating the following steps, that is, from one side of the large photomask to the other, The crossing direction illuminates the observation illumination, and the inspection is performed while moving in parallel with the one side. After checking the length of the one side, the irradiation area is moved at a specific distance in a direction orthogonal to the one side. For example, the defect inspection method of claim 13, wherein the above-mentioned entire surface inspection is performed on the four sides of the large-scale photomask. The defect inspection method according to claim 11, wherein the moving speed of the irradiation area in the entire surface inspection is in a range of 5 cm / sec to 9 cm / sec. The visual inspection method according to claim 9, wherein in the visually designated information acquisition step, the observation illumination alternately repeatedly irradiates the light state and the non-irradiation state with respect to the main surface of the large photomask by the control unit. The visual inspection method according to claim 16, wherein the control unit sets the observation illumination to the non-irradiated state, and uses a laser pointer to obtain a visually designated position of a defect on the main surface of the large photomask. The appearance inspection method according to claim 16, wherein the large-sized photomask is obtained by using a laser pointer in a state where the brightness of the irradiated light on the large-sized photomask is reduced by alternately switching the above-mentioned irradiated state and non-irradiated state at high speed. Visually specify the position of the defect on the main side. A method for manufacturing a large-sized photomask, which is characterized by using a visual inspection method such as any one of claims 8 to 10 and 16 to 18 or a defect inspection method such as any of claims 10 to 15 Check the steps.