TW202204883A - Light filtering device, optical microscope, and defect observation apparatus - Google Patents

Abstract

The present invention is a light filtering device comprising a shutter that has an axis part and has an openable/closable configuration, and a substrate that has a shutter opening part, the light filtering device having a configuration wherein voltage is applied between the shutter and the substrate, the shutter rotates around the axis part and moves to the shutter opening part and thus is brought into a opening state, and the opening angle of the shutter is adjusted to less than 90 degrees. Accordingly, fatigue fracture of the shutter of the light filtering device to be used for an optical microscope, which is a component of a defect observation apparatus, is prevented, and the life of a shutter array device can be prolonged.

Description

Optical filter device, optical microscope and defect observation device

The present invention relates to an optical filter device, an optical microscope, and a defect observation device.

A defect observation apparatus is equipped with a scanning electron microscope (SEM) or the like, and performs inspection of various defects, foreign matter, etc. (hereinafter referred to as "defects, etc.") generated on the surface of a semiconductor substrate, ie, a wafer, in a semiconductor production line or the like. detection, classification, etc.

It is desired that the defect observation apparatus is further equipped with an optical microscope. The defect observation device has the function of "controlling an optical microscope, and efficiently and automatically detecting defects on the wafer surface and performing coordinate alignment." Regarding minute defects detected by an optical microscope, etc., a component analysis can be performed by observing the shape in detail by controlling the SEM. An optical microscope is expected to be used as a dark field optical microscope (DFOM: Dark Field Optical Microscope).

In addition, the defect observation apparatus has a function of automatically outputting SEM images, classification data of defects and the like, elemental analysis data, and the like, and can also create a defect map from the output data. Furthermore, the defect observation device can also observe, classify, and analyze defects, etc., based on the created defect map. Therefore, the defect observation device is also called a re-inspection SEM. Also, it is also referred to as a defect re-inspection SEM (Defect Review-SEM) or a wafer inspection SEM.

In other words, in the defect observation apparatus, the optical microscope and the SEM have a common platform, and the wafer mounted on the platform can be observed with the optical microscope to specify the position of the detected defect, etc. Observe its defects, etc. For example, according to a defect map with an accuracy of several tens of μm, a dark field microscope of a defect observation device can be used to search for defects in the range of several hundreds of nanometers, and the positions of defects and the like can be specified with an accuracy of several μm or less.

Thereby, the deviation of the coordinate system between the optical microscope and the SEM can be corrected, the success rate of defect observation can be improved, and high productivity can be maintained. Moreover, in the manufacturing process of a semiconductor element, it is possible to detect in advance a defect or the like that causes a defect such as poor insulation of wiring or a short circuit, and to determine the source of the defect, thereby preventing a decrease in yield.

Patent Document 1 discloses a defect observation device including a first imaging unit (optical microscope) and a second imaging unit (SEM), which is set from a plurality of imaging devices of the first imaging unit The imaging conditions of the next imaging device of the first imaging section or the imaging conditions of the second imaging section, and setting the cumulative frame number, acceleration voltage, probe current, imaging magnification, or imaging field of view as imaging conditions of the second imaging section, based on the The position information of the defect detected by an imaging unit and the information obtained by the image acquisition of the first imaging unit calculate a coordinate correction formula, and based on the corrected position information, the defect is imaged by the second imaging unit.

Patent Document 2 discloses an optical filter device provided with a light-shielding plate array, the light-shielding plate array having: holes arranged two-dimensionally on an SOI wafer; and a light shielding plate pattern, which is optically opaque to cover the holes. The thin film is 2-dimensionally arranged on the SOI wafer; and the working electrode is formed on the SOI wafer. Here, SOI is the abbreviation of Silicon on Insulator, and SOI wafer is a structure having an oxide insulating film (BOX layer: Buried Oxide layer) and a surface Si film (SOI portion) formed on a Si substrate. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2019-132637 Patent Document 2: Japanese Patent No. 5867736

Problem to be solved by the present invention

In a dark-field microscope, pupil filters are required for different types of defects, and it is required to have a minute light shielding sheet with a size of 1 mm or less corresponding to various types of defects and the like. I think that by switching the shutters like this, a variety of spatial filters can be formed.

In defect detection by conventional dark-field optical systems that do not use such a light-shielding sheet, the spatial characteristics and polarization characteristics on the pupil plane of scattered light from various defects are utilized, and spatial filters and polarization filters are used to detect defects. wafers, increasing the possibility of identifying defects and wafer roughness that becomes detection noise.

Since the shape of the spatial filter useful for detection differs depending on the type of defect, etc., in order to improve the detection sensitivity of a plurality of defects, a plurality of spatial filters and filter switching mechanisms are required. The reason for this is that by using the filter switching mechanism, the switch portion of the light shield can be selected, and a plurality of spatial filters can be formed.

When the light-shielding sheet performs the opening and closing operation, the amount of deformation of the suspension portion, which is the shaft portion that is elastically deformed, increases. Therefore, there is a possibility that the shaft portion and the peripheral portion of the light shielding sheet are prone to fatigue failure due to repeated switching operations, thereby shortening the life of the light shielding sheet.

The purpose of the present invention is to "prevent fatigue failure of the light shielding plate used in the light shielding plate array device (optical filter device) of the optical microscope, which is a component of the defect observation device, and prolong the life of the light shielding plate array device". means of solving problems

The optical filter device of the present invention includes: a light-shielding plate having a shaft portion and a switchable structure; and a substrate having an opening portion of the light-shielding plate and having a structure for applying a voltage between the light-shielding plate and the substrate, and the light-shielding plate is a It has a structure of "turning around the shaft part and moving to the opening of the light-shielding sheet to be in an open state", and the opening angle of the light-shielding sheet is adjusted to be less than 90 degrees. effect of invention

According to the present invention, fatigue failure of a light shielding sheet used in an optical filter device of an optical microscope, which is a constituent element of a defect observation device, can be prevented, and the life of the light shielding sheet array device can be extended.

FIG. 1 is a schematic configuration diagram showing a defect observation apparatus.

In this figure, the defect observation apparatus 10 includes: a scanning electron microscope 1002 (SEM); an optical microscope 1003 (defect detection unit); a control unit 1006 ; a terminal 1007 ; a recording device 1008 ;

Scanning electron microscope 1002 is installed in vacuum chamber 1005 together with stage 1004 . On the stage 1004, the wafer 1001 can be placed. The wafer 1001 is movable together with the stage 1004, which is movable in the X-axis and the Y-axis. Thereby, any surface of the wafer 1001 can be observed by the scanning electron microscope 1002 and the optical microscope 1003 .

The optical microscope 1003 includes: a laser light source 1010 ; an objective lens 1013 ; an imaging lens 1015 ; and an imaging element 1016 . The objective lens 1013 is installed in the vacuum chamber 1005 . Therefore, a vacuum sealing window 1014 is provided so that the light passing through the objective lens 1013 reaches the imaging element 1016 . Between the vacuum sealing window 1014 and the imaging lens 1015 , a microlens array 1103 , a light shielding plate array device 1101 and a microlens array 1102 are arranged in sequence from the side of the vacuum sealing window 1014 . The light irradiated from the laser light source 1010 is configured to be irradiated to the upper surface of the wafer 1001 through the vacuum sealing window 1011 through the reflection mirror 1012 .

The light reflected on the top of the wafer 1001 passes through the objective lens 1013 and the vacuum sealing window 1014 in sequence, and passes through the microlens array 1103, the light shield array device 1101 and the microlens array 1102 in sequence, and is imaged by the imaging lens 1015, and detected by the imaging element 1016 . As the imaging element 1016, a two-dimensional CCD sensor, a line CCD sensor, a TDI sensor group in which a plurality of TDIs are arranged in parallel, a photodiode array, or the like can be used. Here, CCD is the abbreviation of Charge-Coupled Device. Also, TDI is an abbreviation for Time Delay Integration.

The scanning electron microscope 1002 and the optical microscope 1003 are fixed to maintain a correct distance.

The control unit 1006 includes: a platform control circuit 1018 ; a SEM imaging system control circuit 1019 ; an image processing circuit 1020 ; an external I/O interface 1021 ; The platform control circuit 1018 , the SEM imaging system control circuit 1019 and the image processing circuit 1020 are connected to the external I/O interface 1021 , the central processing unit 1022 and the memory 1023 via the bus bar 1024 . The stage control circuit 1018 , the SEM camera system control circuit 1019 and the image processing circuit 1020 are circuits used to move the wafer 1001 , observe defects on the surface of the wafer 1001 and perform other operations. The image processing circuit 1020 integrates the signals of the images acquired by the imaging element 1016, performs data conversion, etc., and determines the type of defects and the like, and specifies the position and size thereof. In this manual, information about the results of discrimination, identification, etc. is referred to as "defect information".

The defect information is input to the recording device 1008 or the memory 1023 . The memory 1023 is mainly used for temporary storage. On the other hand, the recording device 1008 can be used to store and keep the acquired defect information.

In the control unit 1006, based on the defect information, the stage control circuit 1018 controls the stage 1004, and the SEM imaging system control circuit 1019 controls the scanning electron microscope 1002. Further, in the control unit 1006, any or all of the defects and the like detected by the optical microscope 1003 are observed in detail, and classification of the defects and the like, analysis of the causes thereof, and the like are performed. In addition, the control unit 1006 also performs control of the focus or output of the SEM image, control of analysis, analysis of data obtained by the scanning electron microscope 1002, position correction of defects and the like obtained by the optical microscope 1003, and the like. . In addition, in the control unit 1006, display on the terminal 1007, data transfer via the network 1009, and the like may be performed.

In the terminal 1007, conditions for observation of defects and the like are set. Moreover, in the terminal 1007, parameter setting for controlling the scanning electron microscope 1002, the optical microscope 1003, and the stage 1004 is performed. In addition, in the terminal 1007, the setting regarding the switching operation of the light-shielding plate (described later) of the light-shielding plate array device 1101 is also performed. Furthermore, in the terminal 1007, the angle (opening angle) of the light shielding sheet when it is opened may be adjusted to an appropriate value. In this case, a method of “adjusting the voltage applied to the light-shielding plate array device 1101 while confirming the image converted from the image obtained by the imaging element 1016 to the pupil image at the terminal 1007” may be adopted. . Thereby, failures, such as adhesion to a board|substrate, a shaft part of a light-shielding sheet, etc. which arise by opening a light-shielding sheet too much can be prevented.

The force of the elastic body that "returns to the closed state against the stress in the open state of the light-shielding sheet" acts on the shaft portion of the light-shielding sheet. The opening angle is determined by the balance between the force and the electrostatic force to open the light-shielding sheet generated by applying the above-mentioned voltage. Therefore, the opening angle can be adjusted by adjusting the above-mentioned voltage. The upper limit value of the opening angle of the light-shielding sheet is determined by the above-mentioned voltage.

FIG. 2 is a schematic configuration diagram showing an optical microscope, which is a defect detection unit of the defect observation apparatus.

In this figure, the optical microscope 20 includes an imaging element 100 (sensor), an imaging lens 101 , and an objective lens 102 . Microlens arrays 106 and 107 are provided between the imaging lens 101 and the objective lens 102 . Between the microlens arrays 106 and 107, a light shielding plate array device 200 (optical filter device) is provided. The microlens arrays 106 and 107 and the light shielding plate array device 200 are arranged in the vicinity of the pupil plane of the optical microscope 20 .

The objective lens 102 is configured so that the light 300 irradiated from the laser light source 103 to the wafer 104 is reflected on the surface of the wafer 104, and the reflected light 301 is incident thereon. The light passing through the objective lens 102 reaches the imaging element 100 through the pupil plane (Fourier transform plane) and the imaging lens 101, and is detected as an electrical signal. In addition, the light 300 irradiated from the laser light source 103 passes through the vacuum sealing window 351 , is reflected by the reflection mirror 352 , and is irradiated to the wafer 104 .

In the case where the defect 108 is present on the wafer 104, the light 300 that contacts the defect 108 is reflected to produce a different reflected light 301 than usual. The reflected light 301 can be detected by the imaging element 100, and the data corresponding to the image of the defect 108 can be obtained by the image processing circuit 1020 of FIG. By moving the platform 105, defects 108 existing on the surface of the wafer 104 can be found.

FIG. 3A is a schematic enlarged view of a light shielding plate array device and a microlens array.

In this figure, a light shielding plate array device 200 is provided between the microlens arrays 106 and 107 . The light-shielding plates 220 of the light-shielding plate array device 200 are all turned on. Therefore, the reflected light 302 passing through the light-shielding sheet array device 200 is converged and focused at the light-shielding sheet opening portion 304 to become light 303 .

FIG. 3B shows a state in which all the light shielding sheets 220 are closed except for a part. In addition, FIG. 3C shows a state in which all the light shielding sheets 210 are closed. In this way, the plurality of light shielding sheets 210 and 220 have a structure that can be independently switched on and off.

3D, 3E and 3F respectively show the spatial filters corresponding to the states of FIGS. 3A, 3B and 3C. 3D, 3E and 3F are views viewed from above or below the light shielding sheet 220. FIG.

In these figures, the closed state 211 of the shading sheet is represented by black, and the open state 221 of the shading sheet is represented by white. By individually performing ON/OFF control on each pixel of the light shielding plate array device 200, a plurality of spatial filters (spatial masks) can be formed. In addition, in FIGS. 3A , 3B and 3C, the light-shielding plates 210 and 220 of the light-shielding plate array device 200 and the lenses of the microlens arrays 106 and 107 are arranged in three rows and three columns. , can also form a larger-scale matrix.

Hereinafter, the embodiment will be described with reference to the drawings. Example 1

FIG. 4A is a perspective view showing the light shielding sheet array device of the first embodiment.

The light-shielding plate array device 200 shown in this figure includes: a light-shielding plate array 205; an electrode array 206; and a carrier 260 (stand). The light-shielding plate array 205 and the electrode array 206 have the substrate 201 and are fixed to the carrier 260 . The light-shielding plate array 205 and the electrode array 206 are each in the shape of a rectangular parallelepiped, and are provided on the slopes of the concavo-convex structure, and the concave-convex structure is provided on the carrier 260 . In other words, the light shielding plate array 205 and the electrode array 206 are arranged on the inclined surface of the carrier 260 . Thereby, the light-shielding plate array 205 and the electrode array 206 are configured to be inclined to the bottom surface of the carrier 260 .

The substrate 201 is divided by the substrate dividing slit 202 .

The light shielding sheet array 205 and the electrode array 206 are then fixed on the adhesive surface 250 by a conductive adhesive to ensure electrical conduction. The light-shielding sheet array 205 and the electrode array 206 are respectively fixed to the carrier wiring 261 by conductive adhesive to ensure electrical conduction. The carrier wiring 261 is disposed on the carrier 260 and the adhesive surface 251 . In addition, a conductive adhesive film, solder, or the like may be used instead of the conductive adhesive, or metal bonding using Au-Au, Cu-Cu, Cu-Sn, or the like may be used instead of the conductive adhesive.

In this figure, although the light shielding sheet 212 (switch plate) is arranged in a matrix of 3 rows and 3 columns, and three electrode arrays 206 are arranged on both sides of the light shielding sheet 212 respectively, but the present invention is not limited to this, for example The light shielding sheet 212 may be arranged in a matrix with 30 rows and 30 columns together with a plurality of electrode arrays 206 . In short, a plurality of light shielding sheets 212 are arranged adjacent to each other.

The size (length, width, height) of each of the light shielding plate array 205 and the electrode array 206 is approximately a rectangular parallelepiped shape of 1 mm×3 mm×1 mm.

FIG. 4B shows one light-shielding sheet array.

In this figure, the light-shielding plate array 205 has: one light-shielding plate support part 203, three light-shielding plates 212 are arranged in a row; three substrates 201; between the substrates 201 . Between the adjacent substrates 201, substrate dividing slits 202a and 202b are provided. In other words, the substrate 201 is divided by the substrate dividing slits 202a and 202b. The insulating layer 270 is integrated with the light-shielding sheet supporting portion 203 . The light shielding sheet supporting portion 203 and the substrate 201 are insulated by the insulating layer 270, and different voltages can be applied to them.

In this embodiment, the light shielding sheet 212 , the light shielding sheet supporting portion 203 and the substrate 201 are formed of silicon (Si). On the other hand, the insulating layer 270 is formed of silicon dioxide (SiO ₂ ).

FIG. 4C shows one electrode array.

As shown in this figure, the electrode array 206 has: three electrode plates 207 without a light shield; and three substrates 201 . Between the adjacent substrates 201, substrate dividing slits 202a and 202b are provided. In other words, the substrate 201 is divided by the substrate dividing slits 202a and 202b. The electrode plate 207 is also divided by slits 204a and 204b. The electrode array 206 is provided with an insulating layer. The substrate 201 and the electrode plate 207 are electrically connected to each other. That is, the substrate 201 and the electrode plate 207 are divided into three by the substrate dividing slits 202a, 202b and the slits 204a, 204b, and different voltages can be applied to these three. In addition, the adjacent substrates 201 are connected by an insulating adhesive. Thereby, the electrode plate 207 can be used as a terminal for connecting the substrate 201 and the outside.

As shown in FIG. 4A , a wire group 240 is connected to the end of the light-shielding sheet supporting portion 203 . In addition, a wire group 241 is connected to the electrode plate 207 . The wire groups 240 and 241 are fixed by wire bonding or the like. Thereby, in order to perform the switching operation of the light shielding sheet 212, it can be set to ON or OFF and a voltage can be applied.

FIG. 5 shows the B-B section of FIG. 4A.

In FIG. 5 , the carrier 260 is provided with a plurality of carrier openings 263 perpendicular to the bottom surface of the carrier 260 . Furthermore, the light-shielding plate array 205 is provided so that the light-shielding plate openings 264 communicate with the respective carrier openings 263 . The light-shielding sheet opening portion 264 is vertically disposed with respect to the upper surface of the light-shielding sheet support portion 203 .

In this embodiment, the width of the carrier opening 263 is 700 μm. The width of the carrier opening 263 is desirably 100 to 1000 μm.

The light-shielding sheet 212 is in a closed state (the light-shielding sheet 223 is closed), and is parallel to the upper surface of the light-shielding sheet support portion 203 . On the other hand, when the shading sheet 212 is opened (the shading sheet 213 is turned on), the angle 280 (opening angle) of the shading sheet is less than 90 degrees.

On the upper surface of the carrier 260 , a carrier insulating layer 262 is provided, and a carrier wiring 261 is formed on the surface of the carrier insulating layer 262 . The carrier wiring 261 and the carrier insulating layer 262 are also disposed between the light shield array 205 and the carrier 260 and between the electrode array 206 and the carrier 260 . The electrical connection between the carrier wiring 261 and the substrate 201 is performed through the substrate bottom surface 232 and the substrate side surface 233 using a conductive adhesive. In other words, the carrier 260 has the carrier wiring 261 electrically connected to the substrate 201 .

Thereby, a voltage can be applied to each of the substrates 201 . In addition, since the carrier insulating layer 262 is provided between the carrier 260 and the carrier wiring 261, it is possible to prevent conduction between adjacent carrier wirings 261.

As shown in this figure, when the light-shielding sheet 213 is opened, the lower end of the light-shielding sheet 212 whose opening angle is less than 90 degrees is connected to the inner side of the substrate 201 facing the upper surface (the right side in the figure) of the light-shielding sheet 212 . The distance between the wall surfaces is minimized in the light shielding sheet opening portion 264 .

Moreover, since the substrate 201 of the light-shielding sheet array 205 is inclined, the shaft portion of the light-shielding sheet 212 protrudes above the carrier opening 263 . In other words, a configuration is formed in which the inner wall surface of the substrate 201 on the shaft portion side of the light shielding sheet 212 partially covers the carrier opening portion 263 . Furthermore, the distance between the upper surface of the light shielding sheet 212 extending downward and the lower end of the inner wall surface of the substrate 201 facing the upper surface of the light shielding sheet 212 (the minimum distance between the light shielding sheet 212 and the inner wall surface of the substrate 201 ) is smaller than that of the carrier The width of the frame opening 263 and the light shielding sheet opening 264 . That is, the effective aperture ratio of the light-shielding sheet array 205 becomes lower. Here, the effective aperture ratio is defined as a ratio (percentage) calculated with the width of the light shielding sheet opening portion 264 as the denominator and the above-mentioned minimum distance as the numerator.

Therefore, it is desirable that the light passing through the carrier opening 263 and the light shielding opening 264 be adjusted to be smaller than the above-mentioned minimum distance, and be focused on the area where the width of the carrier opening 263 or the light shielding opening 264 is small. The angle at which the light is expected to converge (the angle in the longitudinal section of the reflected light 302 and the light 303 in FIG.

Therefore, from the viewpoint of the effective aperture ratio, it is desirable that the inclination of the substrate 201 is small, that is, the inclination of the light shielding sheet opening 264 with respect to the carrier opening 263 is small.

On the other hand, from the viewpoint of reducing the stress of the shaft portion of the light shielding sheet 212, it is desirable to adjust the light shielding sheet angle 280 to be small.

From the above two viewpoints, the shading sheet angle 280 is desirably in the range of 85 degrees to 60 degrees, more desirably in the range of 80 degrees to 60 degrees, and particularly desirably in the range of 75 degrees to 60 degrees. Here, the meaning of the lower limit value "60 degrees" in the above-mentioned range corresponds to a configuration in which it is desired to set the inclination of the substrate 201 to 0 degrees, that is, within the carrier opening 263 and the light shielding opening 264 In the configuration in which the wall surfaces are parallel, the effective aperture ratio is 50% or more. From the viewpoint of "when the effective aperture ratio is less than 50%, the degree of convergence of the light passing through the carrier opening 263 and the light shielding sheet openings 264 becomes a problem, and the distance between the adjacent light shielding sheet openings 264 increases". See, not ideal.

In addition, as shown in FIG. 5, the angle 280 of the shading sheet is sufficient as long as the upper surface of the shading sheet 212 is parallel to the inner wall surface of the carrier opening 263, and does not need to be larger than the angle. Therefore, the light-shielding sheet angle 280 can be a value obtained by subtracting the inclination of the substrate 201 from 90 degrees as an upper limit value.

Fig. 6 shows the A-A section of Fig. 4A.

In FIG. 6 , the state in which the light-shielding sheet 213 is opened and the light-shielding sheet 223 is closed is shown.

FIG. 7 is a top view of the carrier 260 of FIG. 4A.

In this drawing, the carrier wiring 261 is formed so as to include the sloped surface of the concave-convex structure provided on the carrier 260, and to electrically connect the upper edge portion of the carrier opening portion 263 adjacent to the horizontal direction in the drawing. . Between the adjacent carrier wirings 261 , the insulating portions 265 are provided in parallel with the carrier wirings 261 , and are configured so as not to be electrically connected. Example 2

FIG. 8 is a cross-sectional view showing the light-shielding sheet array device of the second embodiment.

In the light-shielding sheet array device 200 shown in this figure, the height of the substrate 201 is set to be lower than that of the first embodiment shown in FIG. 5 . Other structures are the same as those in Figure 5.

By reducing the height of the substrate 201, the length of the light shielding sheet opening 264 which is curved relative to the carrier opening 263 can be shortened, and the opening area through which the optical axis passes when the light shielding sheet 213 is opened can be enlarged. In addition, even if the opening angle of the light shielding sheet 212 is further reduced, the opening area can be secured.

In addition, in order to form the carrier wiring 261 into an appropriate circuit and to change the potentials of the light-shielding sheet support portion 203 and the light-shielding sheet 212, the electrodes may be omitted by connecting wires such as wire groups to the light-shielding sheet support portion 203. array 206. Example 3

FIG. 9 is a cross-sectional view showing the light-shielding sheet array device of the third embodiment.

In the light-shielding sheet array device 200 shown in this figure, the height of the substrate 201 is reduced as in the second embodiment shown in FIG. 8 .

In this figure, the end portions of the adjacent light shielding plate arrays 205 are arranged to overlap. In other words, the substrates 201 of the light-shielding sheet arrays 205 are arranged to partially cover above the light-shielding sheet support portions 203 of the adjacent light-shielding sheet arrays 205 . A gap 290 is provided in the portion where the substrate 201 and the light shielding sheet supporting portion 203 overlap. The electrode array 206 is also arranged in the same overlapping manner. Since the gap 290 is provided, the substrate 201 is not in contact with the light-shielding sheet supporting portion 203 below. This ensures insulation and prevents short circuits. In addition, an insulating material can also be sandwiched instead of providing the gap 290 .

With the above configuration, the interval between the adjacent light-shielding sheet openings 264 can be narrowly set. As a result, the integration degree of the light shielding plate array 205 can be improved, and the pattern of the spatial filter can also be increased.

(Comparative example) FIG. 10A shows the light-shielding sheet array of the comparative example.

The light-shielding sheet 212 shown in this figure is in an over-opened state, and is in close contact with the inner wall surface 282 of the substrate 201 . In this case, there is a possibility that the attached light shielding sheet 212 will not be detached from the inner wall surface 282 and the switch function cannot be obtained. Example 4

FIG. 10B shows the light-shielding sheet array of Example 4. FIG.

In this figure, the convex portion 281 is provided on the inner wall surface 282 of the substrate 201, whereby the contact of the light shielding sheet 212 becomes a part. Therefore, when the light shielding sheet 212 is opened, it may not be fixed. In addition, the upper limit of the opening angle of the light shielding sheet 212 is set by the convex portion 281 .

In addition, in FIG. 5 and the like, although the configuration of “in the closed state of the light shielding plate 212, the upper surface of the light shielding plate array crosses the optical axis obliquely”, the present invention can also be as shown in FIG. 10B. , it is assumed that "in the closed state of the light-shielding plate 212, the upper surface of the light-shielding plate array intersects the optical axis substantially perpendicularly".

FIG. 10C is a view of the light-shielding plate array of this embodiment viewed from above.

The protrusions 281 shown in this figure are arranged in two vertical directions. When the light shielding sheet 213 is opened, the light shielding sheet 212 is supported by a small area. Thereby, even if the over-opening of the shading sheet 212 caused by the excess voltage, the shock or vibration caused by the failure of the platform of the device, the vibration caused by the earthquake, etc., and other abnormal situations occur, and the opening angle of the shading sheet 212 exceeds Setting the range can also prevent the light-shielding sheet 212 from being attached to the substrate 201 and cannot move, thereby ensuring long-term reliability. Example 5

FIG. 11 shows the light-shielding sheet array of the fifth embodiment.

In this figure, a convex portion 283 is provided on a part of the lower surface of the light shielding sheet 212 . Thereby, when the light-shielding sheet 212 is opened excessively, the situation where the light-shielding sheet 212 is attached to the substrate 201 and cannot be moved is prevented. Example 6

FIG. 12A shows the light-shielding sheet array of Example 6. FIG.

In this figure, the light-shielding plate opening 264 of the substrate 201 is formed to be inclined with respect to the bottom surface of the light-shielding plate support portion 203 .

FIG. 12B shows a state in which the light-shielding sheet array of this embodiment is installed on the carrier.

As shown in this figure, since the light-shielding sheet opening 264 of the substrate 201 has an inclined shape, when the light-shielding sheet array 205 is installed on the carrier 260 at a predetermined angle, the inner wall surface of the carrier opening 263 is It becomes substantially parallel to the inner wall surface of the light-shielding sheet opening part 264 . In other words, the carrier opening portion 263 and the light shielding sheet opening portion 264 communicate with each other substantially in parallel. Thereby, the carrier opening part 263 and the light shielding sheet opening part 264 can be arranged substantially parallel to the optical axis.

In this way, a configuration in which the inner wall surface of the substrate 201 covers the carrier opening 263 with the optical axis as a reference can be avoided, and the effective aperture ratio of the light shielding sheet array 205 can be improved. In addition, the opening angle of the light shielding sheet 212 can be reduced.

In this embodiment, the inner wall surface of the opening portion 264 of the light-shielding sheet is not parallel to the inner wall surface of the light-shielding sheet supporting portion 203 . Therefore, we think that even when the opening angle of the light-shielding sheet 212 is the largest, the light-shielding sheet 212 will not be parallel. It does not come into close contact with the inner wall surface of the opening 264 of the light-shielding sheet, but may be configured as "provided with the convex portion 281 of Fig. 10B or the convex portion 283 of Fig. 11 to surely prevent close contact".

With the configuration of this embodiment, the spot diameter of the light-shielding sheets 212 condensed by the microlens array can be increased, and the design margin of the microlens array can be improved. In addition, this case also contributes to the reduction of the cost of the microlens.

In addition, the light-shielding plate array of the present embodiment is formed by tilting the substrate 201 and setting it in the dry etching device when the dry etching device is used to etch and remove the silicon of the substrate 201 . Example 7

FIG. 13 is a top view showing details of the light-shielding plate array of Example 7. FIG.

In this figure, the light-shielding sheet 2001 that performs the switching operation is supported by the light-shielding sheet support portion 2002 constituting the same plane via the torsion bar 284 (shaft portion). The light shielding sheet 2001 is connected near the center of the torsion bar 284 . A slit 2003 is provided between the light-shielding sheet 2001 and the light-shielding sheet support portion 2002 . In addition, a slit 2004 is provided between the light-shielding sheet support portion 2002 and the torsion bar 284 .

The central axis of the torsion bar 284 is linear, and the cross section is square, rectangular, circular, elliptical, or the like. Mechanically, the system is desirably a circular shape, but from the viewpoint of ease of manufacture, a square or rectangular shape is desirable.

When the shading sheet 2001 is opened, torsional stress is generated on the torsion bar 284 . When the electrostatic force generated by the application of the voltage acts, since the light shielding sheet 2001 is opened, torsional stress is generated. When the voltage application is stopped, the electrostatic force disappears, the light shielding sheet 2001 is closed and the torsional stress disappears. In this way, the torsion bar 284 functions as a torsion bar spring (elastic body).

In short, as shown in this figure, the light shielding sheet 2001 has a structure of a single door with a torsion bar 284 as a shaft portion.

When the opening angle of the light shielding sheet 2001 reaches 90 degrees, the torsional stress becomes the maximum. Therefore, when considering the fatigue failure of the torsion bar 284 and its surroundings, the opening angle of the light shielding sheet 2001 is desirably smaller than 90 degrees. Example 8

FIG. 14 is a top view showing details of the light-shielding plate array of Example 8. FIG.

In this figure, the light-shielding sheet 2001 that performs the switching operation is supported by the light-shielding sheet support portion 2002 constituting the same plane via a meander bar 285 (shaft portion). A slit 2004 is provided between the light-shielding sheet support portion 2002 and the meandering rod 285 . The meandering rod 285 has, for example, a sine-wave shape with a central axis and a square, rectangular, circular, elliptical, or the like in cross section.

When the light-shielding sheet 2001 is opened, stress is generated in the direction "the bending portion of the meandering rod 285 that intersects the direction of the rotation axis of the light-shielding sheet 2001 (the longitudinal direction of the shaft portion) extends".

According to this structure, compared with the case where the torsion bar 284 of FIG. 13 is used, the local stress can be reduced and the reliability as a light-shielding plate array can be improved.

Next, the driving method of the light shielding sheet will be described.

FIG. 15 schematically shows a cross-section of the light-shielding sheet array.

In this figure, a voltage is applied to the light-shielding sheet 212 via the light-shielding sheet support portion 203 to make it a positive potential (V1), and a voltage is applied to the substrate 201 to make a negative potential (V2). Due to the potential difference generated in this way, electrostatic force is generated to open the light shielding sheet 212 .

As shown in this figure, the lower surface of the light shielding sheet 212 is positively charged, and the inner wall surface 282 of the substrate 201 is negatively charged. Thereby, the light-shielding sheet 212 is rotated around the shaft portion, and as a result, the light-shielding sheet is opened.

When the application of the voltage is stopped, it will return to the state where the shading sheet is closed by the restoring force of the shaft.

For example, when V1 is set to +10 to 100V as a positive potential, and V2 is set to -10 to -100V as a negative potential, the applied voltage is 20 to 200V. However, the size of the light shielding sheet 212 also varies, and the present invention is not limited to the above example.

In addition, in the above-mentioned embodiment, although the light-shielding plate array device fabricated by combining parts such as a light-shielding plate array, an electrode array, a carrier, etc. is shown, the present invention is not limited to such an embodiment. By combining the surface oxidation treatment, photolithography, etching, vapor deposition, ion implantation, etc. of silicon used in the semiconductor manufacturing process, the parts corresponding to the light-shielding plate array, electrode array, carrier, etc. are formed without making parts. The combination of the light-shielding plate array device as an integral body.

10: Defect observation device 20: Optical Microscopy 100: camera element 101: Imaging Lens 102: objective lens 103: Laser light source 104: Wafer 106, 107, 1102: Microlens Arrays 108: Defect 200,1101: Shade array device 201: Substrate 202, 202a, 202b: Substrate Dividing Slits 203, 2002: Shading sheet support 204a, 204b: Slit 205: Shade Array 206: Electrode Array 207: Electrode plate 211: The shutter is closed 212, 220, 2001: Shades 221: The shading sheet is on 240, 241: Line group 250,251: Adhesive side 260: Carrier 261: Carrier wiring 263: Carrier opening 264: Shading sheet opening 265: Insulation 270: Insulation layer 281, 283: convex part 282: inner wall surface 284: Torsion Bar 285: Snaking Rod 290: Clearance 303: Light 304: Shading sheet opening 300: light 301, 302: Reflected Light 351: Vacuum Sealed Windows 352: Reflector 1001: Wafer 1002: Scanning Electron Microscopy 1003: Optical Microscopy 1004: Platform 1005: Vacuum tank 1006: Control Department 1007: Terminal 1008: Recording Device 1009: Internet 1010: Laser light source 1013: objective lens 1015: Imaging Lenses 1016: Camera Components 1018: Platform Control Circuit 1019: SEM camera system control circuit 1020: Image Processing Circuits 1021: External I/O 1022: Central Computing Department 1023: Memory 2003, 2004: The Slit

1 is a schematic configuration diagram showing a defect observation apparatus according to an embodiment. [ Fig. 2] Fig. 2 is a schematic configuration diagram showing an optical microscope, which is a defect detection unit of the defect observation apparatus of Fig. 1 . [ Fig. 3A ] A schematic enlarged view showing a light shielding plate array device and a microlens array. [ Fig. 3B ] A schematic enlarged view showing a state except that a part of the light-shielding plate constituting the light-shielding plate array device of Fig. 3A is closed. [ Fig. 3C ] A schematic enlarged view showing a state in which all the light-shielding plates constituting the light-shielding plate array device of Fig. 3A are closed. [ FIG. 3D ] A diagram showing a spatial filter corresponding to the state of the light shielding plate array device of FIG. 3A . [ Fig. 3E ] A diagram showing a spatial filter corresponding to the state of the light-shielding plate array device of Fig. 3B . [ FIG. 3F ] A diagram showing a spatial filter corresponding to the state of the light shielding plate array device of FIG. 3C . 4A is a perspective view showing the light-shielding sheet array device of Example 1. FIG. [ Fig. 4B ] A perspective view showing one light-shielding sheet array. [ Fig. 4C ] A perspective view showing one electrode array. [FIG. 5] B-B sectional view of FIG. 4A. [Fig. 6] A-A sectional view of Fig. 4A. [Fig. [Fig. 7] A top view of the carrier of Fig. 4A. 8 is a cross-sectional view showing a light-shielding sheet array device of Example 2. FIG. 9] Fig. 9 is a cross-sectional view showing a light-shielding sheet array device of Example 3. [Fig. 10A is a cross-sectional view showing a light-shielding sheet array of a comparative example. FIG. 10B is a cross-sectional view showing the light-shielding sheet array of Example 4. FIG. [FIG. 10C] A top view showing the light-shielding sheet array of Example 4. [FIG. 11 is a cross-sectional view showing a light-shielding sheet array of Example 5. FIG. 12A is a cross-sectional view showing the light-shielding sheet array of Example 6. FIG. [ Fig. 12B ] A cross-sectional view showing a state in which the light-shielding sheet array of Example 6 is installed on a carrier. [FIG. 13] A top view showing details of the light-shielding sheet array of Example 7. [FIG. [FIG. 14] A top view showing details of the light-shielding sheet array of Example 8. [FIG. [ Fig. 15] Fig. 15 is a schematic cross-sectional view showing a light-shielding sheet array according to an embodiment.

200: Shade array device

201: Substrate

203: Shading sheet support

205: Shade Array

206: Electrode Array

207: Electrode plate

212: Shades

213: Open the shade

223: Close the shade

232: Bottom surface of substrate

233: Substrate side

241: Line Group

251: Adhesive Noodles

260: Carrier

261: Carrier wiring

262: Carrier insulation

263: Carrier opening

264: Shading sheet opening

280: shade angle

Claims (18)

An optical filter device, characterized by the following: a light-shielding sheet having a shaft portion and having a switchable structure; and a substrate having a light-shielding sheet opening, and has a structure for applying a voltage between the light shielding sheet and the substrate, The light-shielding sheet has a structure of "turning around the shaft portion and moving to the opening of the light-shielding sheet to be in an open state", The opening angle of the light-shielding sheet is adjusted to be less than 90 degrees. The optical filtering device of claim 1, wherein, The above-mentioned light shielding sheet has a structure that "in the closed state, it intersects with the optical axis substantially perpendicularly". The optical filtering device of claim 1, wherein, The above-mentioned light-shielding sheet has a structure that "in the closed state, it crosses the optical axis obliquely". The optical filtering device of claim 1, wherein, A plurality of the aforementioned light shielding sheets are arranged adjacent to each other. The optical filtering device of claim 4, wherein, The above-mentioned plurality of the above-mentioned light-shielding sheets have a structure that can be individually switched on and off. The optical filtering device of claim 1, wherein, The said opening angle of the said light-shielding sheet has the structure that "it is adjusted in the range of 85 degrees to 60 degrees". The optical filtering device of claim 1, which includes: a light-shielding sheet array, comprising the aforementioned light-shielding sheet, a light-shielding sheet support portion and the aforementioned substrate; and a carrier, provided with the aforementioned light-shielding plate array, The carrier has carrier wirings electrically connected to the substrate. The optical filtering device of claim 7, wherein, In the aforementioned carrier, a carrier opening is provided, The aforementioned light-shielding plate array is arranged on the inclined surface of the aforementioned carrier, The light-shielding sheet opening is communicated with the carrier opening. The optical filtering device of claim 8, wherein, The opening of the light shielding sheet is curved relative to the opening of the carrier. The optical filtering device of claim 8, wherein, The light-shielding sheet opening and the carrier opening communicate with each other substantially in parallel. The optical filtering device of claim 8, wherein, The adjacent light-shielding plate arrays are arranged so as to partially overlap. The optical filtering device of claim 1, wherein, A convex portion is provided on the inner wall surface of the substrate or the baffle, and the upper limit of the opening angle is set by the convex portion. The optical filtering device of claim 1, wherein, The upper limit of the opening angle of the light shielding sheet is determined by the voltage. The optical filtering device of claim 1, wherein, The aforementioned shaft portion is composed of a torsion bar or a meandering bar. The optical filtering device of claim 7, wherein, An insulating layer is provided between the light-shielding sheet support portion and the substrate. The optical filtering device of claim 7, further comprising: electrode array, The electrode array is arranged on the carrier. An optical microscope, characterized by the following: The optical filtering device of claim 1; and Microlens array. A defect observation device, characterized by the following: an optical microscope as claimed in claim 17; and Scanning Electron Microscope.

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