JP2001249013A - Solid shape detector and pattern inspection device and their method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily and accurately detect a solid shape of wiring pattern of electronic circuit substrate and the like without any blind spot. SOLUTION: A reflection beam group of a plurality of irradiation beams from an inspection object 11 is equally separated into a reflection beam groups L1, L2, L3 and L4. A plurality of reflection beam of the reflection beam group L1 are focused with an imagery lens 22 and are received with individual cells of a line sensor 30 by way of each pin hole of a pin hole array 26. Similarly in the beam groups L2, L3 and L4, a plurality of reflection beams are focused with imagery lenses 23 to 25 and are received with individual cells of line sensors 31 to 33 by way of each pin hole of pin hole arrays 27 to 29. The pin hole arrays 26 to 29 have different positions shared with the detection object 11, and the height at beam irradiation point of the inspection object 11 is detected from the detection output of the cells receiving the reflection beams against the same irradiation beams of the line sensors 31 to 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for inspecting a three-dimensional shape at high speed in an appearance inspection of an industrial product, and more particularly to a wiring pattern of an electronic circuit board, for example, a printed wiring board or a ceramic green sheet. More particularly, the present invention relates to an apparatus and method for inspecting a wiring pattern printed on a printed circuit board, and a soldered portion of an electronic circuit board.

[0002]

2. Description of the Related Art Conventionally, as a technique for inspecting a thickness defect of a wiring pattern of fine metal particles formed on a green sheet used for a ceramic substrate, Japanese Patent Application Laid-Open Nos. Hei 3-279805, Hei 4-290909, Hei 5 -661
There is a method disclosed in Japanese Patent Publication No. In these methods, when irradiating a wiring pattern with a light beam (laser light) and detecting the reflected light, one or both of the light beam irradiation direction and the reflected light detection direction are applied to the substrate. The three-dimensional shape of the pattern is detected by tilting it obliquely. The thickness information of the pattern is obtained by a detection method which is considered to be one of such light cutting methods, and the thickness defect is detected.

As a technique for detecting a three-dimensional shape, there is a method disclosed in JP-A-3-63507 and JP-A-6-201337. These methods detect a plurality of images having different focus positions and calculate a three-dimensional shape from a group of detected images.

Further, as another technique for detecting a three-dimensional shape, a confocal method and a method considered to be a modification thereof are disclosed in JP-A-5-240607, JP-A-5-332733, JP-A-4-265918, JP-A-9-126
No. 739 and Japanese Patent Application Laid-Open No. 9-257440. These are methods of irradiating a light beam (laser light), detecting reflected light at a plurality of positions having different focal positions, and calculating a three-dimensional shape from their signal intensities.

[0005]

The three-dimensional shape detection method disclosed in Japanese Patent Application Laid-Open Nos. Hei 3-279805, Hei 4-290909, and Hei 5-66118 described above uses a light beam. Since it is necessary to scan over the substrate to be inspected, it is difficult to increase the detection speed.
In addition, scanning a light beam with a polygon mirror or the like is disadvantageous in terms of speed as compared with, for example, a detection method using a line sensor. In addition, since the optical axis needs to be inclined obliquely, there is a problem that a blind spot in which the shape cannot be detected occurs.

In addition, the three-dimensional shape detection method disclosed in the above-mentioned Japanese Patent Application Laid-Open Nos. Hei 3-63507 and Hei 6-201337 requires means for detecting a plurality of images having different focal positions. . Japanese Unexamined Patent Publication No. 3-63507
According to the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-157, the inspection target substrate is mounted on a Z stage, and an image is detected while moving the Z stage up and down. Therefore, a long detection time is required. JP-A-6-201
In the method disclosed in Japanese Patent Publication No. 337, a method of moving the optical system up and down is also described, but still has a problem that the detection time becomes long.

Further, in the three-dimensional shape detection system disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-240607, it is necessary to scan the substrate to be inspected with a light beam, so that it is also difficult to increase the detection speed. .

[0008] Further, Japanese Patent Application Laid-Open No. 5-332733 is disclosed.
In the three-dimensional shape detection method disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, the detection speed is increased by irradiating the detection target with a sheet-like beam and detecting the reflected light with a line sensor, but the detection target is increased. Since reflected light beams from different irradiation points on an object overlap each other and are detected by the line sensor, there is a problem that detection accuracy is poor.

Further, Japanese Patent Application Laid-Open No. 4-265918 discloses
And Japanese Patent Application Laid-Open Nos. 9-126439 and 9-2
In the three-dimensional shape detection method disclosed in Japanese Patent No. 57440, a plurality of beam spots arranged in a two-dimensional lattice are irradiated onto a detection target, and the height of each beam spot is simultaneously detected. The detection speed can be greatly increased as compared with the one-point detection type confocal method. But,
These methods are advantageous when the detection target area is small enough to be detected by a single imaging because the detection target is imaged by the two-dimensional CCD sensor. However, the detection target area is large, and the detection target area is large. If it cannot be detected by imaging, it is necessary to move the detection target or the detection optical system in a planar manner and repeatedly image the image. For detection using a line sensor or a TDI (Time Delay / Integration type: Time Delay Integrated) sensor, On the other hand, it is disadvantageous in terms of speed.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and to eliminate a blind spot in the inspection of a wiring pattern or the like of an electronic circuit board and to improve a detection speed and a detection accuracy and a three-dimensional shape detection device. An object of the present invention is to provide an inspection apparatus and a method thereof.

[0011]

In order to achieve the above-mentioned object, a three-dimensional shape detecting apparatus and method according to the present invention provide a convergent beam of n (where n is an integer of 2 or more) point-like spots. The object to be detected is irradiated, and n reflected beams from the object due to the irradiation are set as a reflected beam group, and the number of the reflected beam groups is m (where m is an integer of 2 or more).
A line sensor comprising n divided cells each of which is divided equally into a plurality of reflected beam groups, and each of the divided reflected beam groups is formed as a detection beam group by a separate imaging lens. Are provided, and each detection beam of the detection beam group formed by the imaging lens is received by a separate cell of the line sensor. These m line sensors determine the position of the conjugate detection target. These are different from each other, and the detection outputs of the cells that receive the detection beams divided from the same reflected beam by these m line sensors are collectively processed to determine the irradiation point of the convergent beam on the detection target. The height is calculated.

With this configuration, it is possible to simultaneously detect the heights of the n convergent beam irradiation points of the detection object, and scan the detection object with the n convergent beams to detect the detection object. The three-dimensional shape of the area can be detected at high speed.

Further, the three-dimensional shape detecting apparatus and the method therefor according to the present invention provide an object for detecting a convergent sheet-like beam having n (where n is an integer of 2 or more) spot shapes arranged in parallel as a sheet shape. And the reflection sheet-like beams from the n detection points of the object to be detected by the irradiation as a reflection sheet-like beam group, the numerical aperture in the longitudinal direction of the reflection sheet-like beam is small, and the reflection sheet-like beam is The beam is passed through an opening having a large numerical aperture in the width direction of the beam, and the reflecting sheet-like beam group that has passed through the opening is equally divided into m (where m is an integer of 2 or more), and each of the n detection beams is detected. A group of m reflecting sheet-like beams composed of sheet-like beams is formed, and the m detection sheet-like beam groups are respectively imaged by separate imaging lenses, and each of these detecting sheet-like beams is received by a TDI sensor. , The TDI Each of the sensors has n light-receiving portions for separately receiving the detection sheet-like beams of the corresponding detection sheet-like beam group, and makes the positions of the conjugated detection objects different from each other, and the light-receiving portions are k (However, k is an integer of 2 or more)
Having a cell, a detection sheet-shaped beam is incident, and by sequentially receiving light reception information between the cells, the reflected light amount of the detection target from the same detection point is integrated, By processing the amount of light received by the light receiving units for receiving the respective detection sheet-like beams divided from the same reflection sheet-like beam from the detection object by the m TDI sensors, the detection object is detected. And the height of the irradiation point of the convergent sheet beam is calculated.

With this configuration, the heights of the n convergent beam irradiation points of the detection target can be simultaneously detected, and the detection target is scanned by the n convergent beams to detect the detection target. Since the three-dimensional shape of the area can be detected at high speed and the amount of received light at the same detection point of the detection target is integrated using a TDI sensor, the detection sensitivity is improved and the light collection efficiency of the illumination system is reduced. Will be supplemented.

Further, the pattern inspection apparatus and method according to the present invention detect a three-dimensional shape of a pattern and detect a defect thereof using the three-dimensional shape detection apparatus and method. Such a pattern is, for example, a wiring pattern of an electronic circuit board, such as a wiring pattern printed on a printed wiring board or a ceramic green sheet, or a pattern of a soldered portion of the electronic circuit board, and these defects are detected. can do.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a three-dimensional shape inspection apparatus and a pattern inspection apparatus and a method thereof according to the present invention, wherein 1 is a laser light source, 2 is a beam expander, and 3 is a cylindrical lens. 4 is a micro lens array, 5 is a pinhole array, 6 is a collimating lens, 7 is a polarizing beam splitter, 8 is an aperture, and 9 is 1
/ 4 wavelength plate, 10 is an objective lens, 11 is a detection target, 1
2 is an XY stage, 13 is a work holder, 14 and 15 are relay lenses, 16 to 18 are beam splitters, 19 to 2
1 is a mirror, 22 to 25 are imaging lenses, 26 to 29 are pinhole arrays, 30 to 33 are line sensors, and 34 to 3
7 is an amplifier, 38 to 41 are A / D converters, 42 to 45 are shading correction circuits, 46 to 49 are image memories,
0 is a height calculator, 51 is a control computer, 52 is a stage control board, 53 is a driver, and 54 is a camera control board.

In the conventionally known confocal method,
By irradiating a point spot beam on a certain point on an object (detection target) and detecting the reflected light from the beam irradiation point with a plurality of point-type sensors at different positions, the height of the beam irradiation point is increased. In the first embodiment, a plurality of point-like spot beams are irradiated on an object at the same time, and reflected light from these beam irradiation points is parallelized by a plurality of line sensors having different positions. , The heights of the plurality of beam irradiation points are simultaneously detected.

In the first embodiment, as one specific example, the beam of four spot-like spots is irradiated on the detection target 11, and the reflected light of the four spot-like spots is reflected by the four line sensors 30 to 30 at different positions. A detection system having a four-channel configuration for detection at 33 is used (however, the present invention is not limited to a four-channel configuration, but can be an arbitrary multiple-channel configuration). FIG. 2 shows a one-channel detection system including the line sensor 30 together with the illumination system of the detection target 11. In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and the beam splitters 16 and 18 and the mirror 20 are omitted.

First, the illumination system in FIG. 1 will be described.

The illumination system forms spot-like spot beams discretely arranged on one straight line and irradiates them onto the detection target 11.

The laser light emitted from the laser light source 1 is
After the spot diameter is expanded by the beam expander 2, the light is condensed by the cylindrical lens 3 so that the spot becomes a sheet. A microlens array 4 is arranged near the condensing position of the cylindrical lens 3, and the number of sheet-like spot beams from the cylindrical lens 3 is n (where n is an integer of 2 or more) by the microlens array 4. Are divided into convergent beams. The microlens array 4 has n microlenses arranged in the longitudinal direction of a sheet-like spot of this beam, and each microlens emits a convergent beam one by one. A pinhole array 5 having a pinhole is arranged for each of the condensing points of the microlenses, and a convergent beam from each microlens passes through each pinhole. Each of the n convergent beams passing through the pinhole is converted into a parallel light beam by a collimating lens 6, then turned back by a polarizing beam splitter 7, passes through an aperture 8 and a 波長 wavelength plate 9, and is detected by an objective lens 10. The light is condensed and irradiated on the object 11. As a result, n beam spots are irradiated on the detection target 11 while being arranged in a straight line.

The detection target 11 is fixedly mounted on the XY stage 12 by a work holder 13. If the fixed reference plane of the detection target 11 determined by the work holder 13 is an XY coordinate plane, these n beams The spots are discrete and arranged on a straight line on the surface of the detection target 11.

It is desirable that the center position of these beam spots does not move in the X and Y axis directions even if the height (Z axis direction) of the surface of the detection target 11 changes. A diaphragm 8 is arranged at the position to make it telecentric.

In this illumination system, a cylindrical lens 3, a microlens array 4, and a pinhole array 5 are used in order to suppress a light quantity loss when splitting outgoing light from a single light source 1 into n beams. As a result, the light is collected efficiently.

Next, the imaging system (detection system) of FIG. 1 will be described.

Each of the n reflected beams (hereinafter referred to as “reflected beam group”) L from the detection object 11 is
Is converted into parallel light, and the quarter-wave plate 9 becomes circularly polarized light. Due to the circularly polarized light, the reflected beam group can pass through the polarizing beam splitter 7.

After passing through the polarizing beam splitter 7, the reflected beam group L passes through the relay lenses 14 and 15, and then has a four-channel detection system.
With an optical system composed of 6 to 18 and mirrors 20 and 21,
Each reflected beam is divided into four reflected beam groups L ₁ , L ₂ , L ₃ , and L ₄ such that each reflected beam is divided into four equal parts. And
N pieces of the reflected beam of the reflected beams L ₁ are each, by the imaging lens 22, is focused on the line sensor 30 through the pinhole of the pinhole array 26, the n of the reflected beam of the reflected beams L ₂ may each, The line sensor 3 is passed through the pinhole of the pinhole array 27 by the imaging lens 23.
Is focused on 1, n pieces of the reflected beam of the reflected beams L ₃ also respectively by the imaging lens 24, it is focused on the line sensor 32 through the pinhole of the pinhole array 28, n pieces of the reflected beams L ₄ The reflected beams of the imaging lens 2
5, the light is condensed on the line sensor 33 through the pinholes of the pinhole array 29.

Here, the channel including the line sensor 30 is taken as an example, and the details of the detection system will be described with reference to FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted. In addition, the relay lens 15 in FIG.
The optical system between the mirror and the mirror 21 (that is, the beam splitters 16 and 19 and the mirror 20) is omitted. The same applies to other channels. Here, it is assumed that n = 4, four converging beams are formed by the illumination system, and four beam spots are irradiated on the detection target 11.

In FIG. 2, an object 11 to be detected is irradiated with _four convergent beams l ₁ , l ₄ , l ₃ and l ₄ , and these reflected beams form an image from a mirror 21 as a reflected beam group L _1. The light is sent to the lens 22. The pinhole array 26 includes pinholes 26 ₁ , 26 for each reflected beam of the reflected beam group L _1.
2 , 26 ₃ , and 26 _4.
In the same manner, the four cells (light receiving elements) 30 ₁ , 3
0 ₂ , 30 ₃ , and 30 ₄ . Reflected beam by converging beam l ₁ in the reflected beams L ₁ is condensed by the imaging lens 22, a pinhole 2 of the pinhole array 26
6 ₁ is received by the cell 30 ₁ of the line sensor 30 via a reflection beam by converging beam l ₂ in the reflective beam groups L _1,
The light is condensed by the imaging lens 22 and the pinhole array 2
6 of the line sensor 30 through the 6 pinholes 26 ₂
0 ₂ is received by the reflected beam by converging beam l ₃ in the reflection beams L ₁ is condensed by the imaging lens 22,
Is received by the cell 30 ₃ of the line sensor 30 through the pin hole 26 ₃ of the pinhole array 26, the reflected beam by converging beam l ₄ in the reflection beams L ₁ includes an imaging lens 22
It is condensed by, and is received by the cell 30 ₄ of the line sensor 30 through the pinhole 26 ₄ of the pinhole array 26.

This is connected to the other line sensors 31, 32, 33
Looking at FIG. 3, as shown in FIG.
1 also has four cells 31 ₁ , 31 ₂ , 31 ₃ , 31 ₄ , and the line sensor 31 also has four cells 32 ₁ , 32 ₂ , 32 ₃ , 3
2 ₄ has a line sensor 31 is also four cells 33 _1, 33
_2, 33 _3, 33 ₄ has, these line sensors 3
In 0-33, the cell 30 _1, 31 _1, 32 _1, 33 ₁ to the reflected beam of the same converging beam l ₁ is, cell 30 _2, 3
1 _2, 32 _2, 33 ₂ to the reflection beam of the same converging beam l ₂ is the reflected beam of the cell 30 _3, 31 _3, 32 _3, 33 ₃ on the same convergent beam l ₃ is, cell 30 _4, 31 _4, 32 ₄ , 33 ₄
The same reflected beam converging beam l ₁ are respectively incident on.

Incidentally, as described above, the imaging lenses 22, 23,
The light is condensed at 24 and 25, and the line sensors 30 and 31, respectively.
The reflected beams incident on 32, 33 are detected by the line sensors 30, 31, 32, 33.
Hereinafter, it is called a detection beam.

In FIG. 2, the position of the convergence point of the detection beam by the imaging lens 22 depends on the distance from the imaging lens 10 to the irradiation surface of the convergent beam on the detection target 11 (hereinafter simply referred to as the irradiation surface). Different. When the distance is a specific value, the convergence point of the imaging lens 22 is the position of the pinhole array 26. When the irradiation surface of the detection target 11 is at such a distance from the imaging lens 10, detection is performed. It is said that the object 11 is at a position conjugate with the pinhole array 26. Therefore, when the detection target 11 is at a position conjugate with the pinhole array 26, the detection beam is converged by the imaging lens 22 to the position of the pinhole array 26. When the detection target 11 is not at a position conjugate with the pinhole array 26, the convergence point of the detection beam is shifted from the position of the pinhole array 26 by the imaging lens 22. For this reason, the beam diameter of the detection beam at the position of the pinhole array 26 differs depending on the distance between the imaging lens 22 and the reflection surface of the detection target 11, and the detection target 11 is conjugated with the pinhole array 26. , The beam diameter of the detection beam at the position of the pinhole array 26 is minimized.

The pinhole 26 in the pinhole array 26
The diameter of ₁ , 26 ₂ , 26 ₃ , 26 ₄ is the beam diameter of the detection beam at the position of the pinhole array 26 when the detection target 11 is at a position conjugate with the pinhole array 26 (that is, the minimum beam diameter). Diameter).
Therefore, when the detection target 11 is at a position conjugate with the pinhole array 26, the detection beam condensed by the imaging lens 22 passes through the pinhole of the pinhole array 26 as it is, and the detection target 11 is If the position deviates from the position conjugate with the hole array 26, the beam diameter of the detection beam at the position of the pinhole array 26 increases, and a part of the beam is shielded by the wall surface of the pinhole array 26. The larger the size, the smaller the amount of light received by the sensor of the line sensor 30.

The convergent beams l ₁ , l ₂ , l ₃ and l ₄ are applied to different positions on the irradiation surface of the object 11 to be detected. Therefore, the irradiation surface has irregularities, and these convergent beams l ₁ ,
If the height (Z direction) differs between the irradiation positions of l ₂ , l ₃ , l ₄ , naturally, the convergent beams l ₁ , l ₂ , l ₃ , l ₄
, The detection target 11 is shifted from the position conjugate with the pinhole array 26 for other convergent beams even if the detection target 11 is at a position conjugate with the pinhole array 26. Therefore, the light reception amount of the cell of the line sensor 30 that receives the detection beam with respect to the convergent beam is smaller than the maximum light reception amount.

The above description is for the channel including the line sensor 30, but the same applies to the other channels in FIG. However, the pinhole arrays 26 and 2
The positions of the detection target 11 conjugate with 7, 28, 29 are sequentially different. Here, the position of the detection target 11 conjugate with the pinhole array 26 is closest to the imaging lens 10, and the detection target 11 conjugated in the order of the pinhole arrays 27, 28 and 29.
Is located far from the imaging lens 10.

[0037] Therefore, now, looking at the convergent beam l ₁ in FIG. 2, the detection beam with respect to the convergent beam l _1, in FIG. 3, the cell 30 ₁ of the line sensor 30, the cell 31 ₁ of the line sensor 31, the line Although is received simultaneously in the cell 33 ₁ of the cell 32 ₁ and the line sensor 33 of the sensor 32, these cells 30 _1, 31 _1, 32 _1, 33 ₁ of the amount of received light irradiation of focused beam l ₁ of the detection target 11 The position depends on the amount of deviation from the position conjugate with the pinhole array 26 and differs from each other.

Here, for example, the cell 30 _{1 of} the line sensor 30 and the cell 3 of the line sensor 31 receive a detection beam corresponding to the same convergent beam applied to the detection target 11.
11 ₁ , cell 32 ₁ of line sensor 32 and line sensor 3
The detection output of each of the 3 cells 33 ₁ is shown, the horizontal axis is the sensor position,
When plotting the vertical axis as the output of the line sensor, a result as shown in FIG. 4 is obtained. Then, when the plotted detection output is interpolated by, for example, a Gaussian function, a characteristic curve A shown by a broken line is obtained, and the sensor position at the peak of the characteristic curve A is determined by the detection target 11 and the pinhole array. Are conjugate with each other, and the height of the reflection surface of the detection target 11 which is conjugate with each of the pinholes 26, 27, 28, and 29 is obtained in advance and known, so that the characteristic curve is obtained. The height of the reflection surface of the detection target 11 can be determined from the sensor position at which the peak of A occurs.

In this embodiment, four convergent beams l ₁
Irradiating a to l ₄ to detect the object 11, these convergent beam l ₁
Because of the use of line sensors 30 to 33 having four cells for detecting a detection beam for to l _4, for each irradiation position of the focused beam l ₁ to l ₄ of the detection object 11 as shown in FIG. 4 The characteristic curve A can be obtained, and therefore, the heights of four positions of the detection target 11 can be detected simultaneously.

In order to obtain such a height at the detection target 11, the line sensors 30, 31, 3 in FIG.
The detection signals of the amplifiers 2 and 33 are supplied to the amplifiers 34, 35, 36 and 37, respectively.
Are amplified by the A / D converters 38, 39, 40,
At 41, the analog signal is converted into a digital signal. These digital detection signals are output to a shading correction circuit 4.
After being subjected to shading correction processing in 2, 43, 44, and 45, they are stored in image memories 46, 47, 48, and 49.
The height calculator 50 stores the image memories 46, 47, 4
Line sensors 30, 31, 3 stored in 8, 49
The detection outputs 2 and 33 are compared as described with reference to FIG. 4, and the height of each position of the detection target 11 is calculated. The height information obtained by the calculation is read by the control computer 51.

In order to detect the height of the entire inspection area of the object 11 to be detected, it is necessary to move the irradiation positions of the convergent beams l ₁ , l ₂ , l ₃ and l ₄ over the entire surface of the object 11 to be detected. And for this purpose the convergent beams l ₁ , l ₂ ,
Scanning of the entire inspection area by l ₃ and l ₄ is performed as follows.

That is, when a command is output from the control computer 51 to the stage control board 52, the stage control board 52 generates a drive pulse to the driver 53 in accordance with the command from the control computer 51. With this drive pulse, the driver 53 drives the XY stage 12 to converge beams l ₁ , l ₂ , l for one step.
_3, a direction perpendicular to the arrangement direction of l ₄ (i.e., Y-axis direction)
Sequentially. An encode signal output from a rotary encoder (not shown) built in a servo motor (not shown) of the XY stage 12 is supplied from a driver 53 to the stage control board 52, and the inspection of the detection target 11 is performed. The frequency is divided into a clock having a cycle corresponding to the size of a detection pixel which is a unit of height detection in the area, and is supplied to the camera control board 54 as a drive pulse. The camera control board 54 drives the line sensors 30 to 33 with this drive pulse. That is, each of the line sensors 30 to 33 outputs a detection signal to the amplifiers 34 to 37 in synchronization with the drive pulse. Thus, the moving speed of the XY stage 12 and the driving of the line sensors 30 to 33 are synchronized.

FIG. 5 is a diagram showing a specific example of such a scanning method.

In the scanning method shown in FIG. 5A, the XY stage 12 is moved in the Y direction for the first time, so that the inspection area is moved from one end to the other in the −Y direction by the convergent beams l _{1 to} l _4. Is reached, the XY stage 12 is moved in the −X direction by a distance D that is four times the scanning pitch, and the scanning area is shifted by this distance D in the X direction.
The stage 12 is moved in the −Y direction to perform a second scan in the Y direction. In the same manner, each time the scan is shifted by the distance D in the X direction, scanning is performed in the Y direction or the −Y direction, and this scanning is repeated until the entire inspection area is scanned.

FIG. 5 (b) shows that the distance between the convergent beams l _{1 to} l ₄ cannot be narrowed due to restrictions such as the distance between the cells of the line sensors 30 to 33 and the distance between the micro lenses of the micro lens array 4. ) Is an effective method when precise detection is not possible. First, the XY stage 12 is
When scanning is performed in the −Y direction with the convergent beams l _{1 to} l ₄ in this direction, the scanning pitch D _{1 in} this case is large. When the scanning reaches the one end of the inspection area, the XY stage 12 is moved to the scanning pitch D _1. distance of ₁ 1/2 to move in the -X direction, then by moving the XY stage 12 in the -Y direction,
Scanning is performed in the Y direction between the scanning lines already formed by the convergent beams l _{1 to} l ₄ . After the first reciprocating scan is completed, the XY stage 12 is moved in the −X direction by a distance D _{2 that is} four times the scan pitch D ₁ to move the scan area by this distance D ₂ . Direction, the XY stage 12 is moved in the Y direction and the −Y direction, and the second reciprocating scan similar to the first is performed. Hereinafter, similarly, this operation is repeated to scan the entire inspection area.

In FIG. 5B, the XY stage 12 is moved in the −X direction by the distance D ₂ in one reciprocal scan to shift the scanning area by the distance D _{2 in the} X direction. multiple times or not (more +1/2) times reciprocating scanning the XY stage 12 performs a movement in the X direction by said distance D _2, may be to scan the next scanning region.

By the way, in the first embodiment, in the same line sensor, a detection beam to be incident on a corresponding cell is prevented from leaking to another adjacent cell, that is, light leaking to an adjacent cell is generated. I try not to. For example, in FIG. 3, the detection beam to be incident on the cell 30 ₂ of the line sensor 30 is leaking to the adjacent cell 30 ₁ and the cell 30 _3. Hereinafter, this point will be described.

[0048] Figure 6 is a diagram showing a state of the detection beam with respect to the cell 30 ₁ of the line sensor 30 when the height of the examination region of the detection object 11 has changed, 55 is an optical system, FIG. 1 Parts corresponding to those in FIG. 3 are denoted by the same reference numerals.

In the figure, an optical system 55 shows the optical system from the imaging lens 10 to the imaging lens 22 in FIG. 1, and the magnification of the optical system 55 is β, and the detection numerical aperture is NA _d . I do.

Now, the reflected beam when the converging beam converges on the inspection surface of the object 11 to be detected, and hence the detected beam is indicated by a solid line arrow, and the beam spot diameter of the inspection object 11 on the inspection surface at this time is 2r. when, at this time, the optical system 55, the detection beam converges at the position of the pinhole 26 ₁ of the pinhole array 26. The spot diameter of the detection beam at this time is 2βr. Therefore, the diameter of this pinhole 26 ₁ is set slightly larger than 2βr, and the total light amount of this detection beam is
It is received by the cell 30 ₁ 0.

On the other hand, the inspection surface of the detection target 11 has irregularities, and a maximum ΔZ
Only the height changes. The detection beam corresponding to the convergent beam applied to the inspection surface of the detection target 11 changed by the maximum height ΔZ is indicated by a broken arrow. In this case, this detection beam converges in front of the pinhole array 26, and the spot diameter of the detection beam at this convergence point is 2β
r, the radius R of the beam spot at the position of the pinhole 26 ₁ is

(Equation 1) Becomes Accordingly, the detection beam, the outer part is shielded by the pinhole array 26 than its radius .beta.r, it does not enter the cell 30 ₁ only a part thereof.

FIG. 7 is a diagram showing a state of a detection beam with respect to two adjacent convergent beams irradiated on portions of the inspection object 11 having different heights in the inspection area.
6 are given the same reference numerals.

In the figure, it is assumed that the irradiation beam is converged on the point X ₂ of the detection target 11 and that the point X ₁ is higher than the point X ₂ by the height ΔZ. . If the distance between these two points X ₁ and X ₂ is ΔX, this distance ΔX is the resolution of detection,
The smaller the distance ΔX, the higher the resolution. The pin holes 26 ₁ of the pinhole array 26 is for detecting the beam from point X _1, pinhole 26 _{and second} pinhole array 26 is for detecting the beam from point X _2.

[0054] Now, looking at the detection beam shown by the dashed arrows from point X _1, since the illumination beam in this regard X ₁ is not converged, the detection beam is converged in front of the pinhole array 26, the pin radius R of the detection beam at the holes 26 ₁ becomes the largest of the above formula (1).
Incidentally, in this state, it depends on the pinhole 26 ₂ next detection beam from the point X ₁ it is necessary to prevent leakage occurs light, for this purpose, the pin holes 26 _1, 262 ,... The opening diameter is q _P and the pitch is P
(This is also the cell pitch of the line sensor 30)

(Equation 2) Must be satisfied.

In order to prevent the leakage light, it is necessary to prevent the light of the detection beam from passing through the corresponding pinhole of the pinhole array 26 and hitting the adjacent cell of the line sensor. For example, in the state shown in FIG. 7, the light passing through the pinhole 26 _1, it is necessary to not expose to the cell 30 ₂ for the pin hole 26 ₂ next.

Therefore, in FIG. 6, the distance between the pinhole array 26 and the light receiving surface of the cell of the line sensor 30 is L _PC , and the opening diameter of the cell is q _C (where q _C / 2 ≦ P / 2). Then, the radius of the spot of the detection beam on the light receiving surface of the sensor is expanded by L _PC · NA _d from the pinhole diameter.

(Equation 3) That is, it does not matter if this does not affect the adjacent cell. Since the shortest distance to the cell next to the center of a cell is P- (q _C / 2),

(Equation 4) Must be satisfied.

As described above, by setting the specifications of the optical system 55, the pinhole array 26, and the line sensor 30 so as to satisfy the above equations (2) and (3), the light leaking to the adjacent cells is obtained. Can be prevented, and a detection output of only the detection beam by the corresponding convergent beam can be obtained from each cell of the line sensor 30. Accordingly, in a state where such a condition is satisfied, as shown in FIG.
By performing the scanning of the inspection area, it is possible to accurately detect the height (accordingly, the three-dimensional shape) in the entire inspection area. In addition, since the detection target 11 is scanned with a plurality of (four in the above description) convergent beams and the heights of a plurality of positions can be simultaneously detected, the conventional method is used. , It is possible to detect at a higher speed.

Here, a specific example of the above specifications for satisfying the above conditions will be described. Detection magnification β: 0.75 times Cell opening diameter q _C : 7.5 μm Pin hole (cell) interval P: 15 μm Pin hole opening diameter q _P : 7.5 μm Detection numerical aperture NA _d : 0.13 Height Detection range ΔZ: 120 μm Distance between the light receiving surface of the cell and the pinhole array L _PC : 0 μm Beam spot radius r: 3 μm However, here, the opening of the cell itself is also used for the pinhole opening, and every other line sensor is used. No cells are actually used, and no pinholes are actually used. Therefore, the distance L _PC is 0 μm. Alternatively, as a line sensor, the cell arrangement interval P is 15 μm, and the opening diameter q _{C of} these cells is 7.5.
The same applies to the case of μm.

By the way, when the conditions of the above equations (2) and (3) are satisfied in order to prevent light leakage to the cell, the distance between the convergent beams l ₁ , l ₂ , l ₃ and l ₄ is not made large. In some cases. For example, the maximum height change ΔZ due to unevenness in the inspection area of the detection target 11 such as a wiring pattern or a soldered portion of an electronic circuit board is known. In this embodiment, even if such a height change occurs in the inspection area of the detection target 11, the configuration is set so as to satisfy the above-described equations (2) and (3) so that light does not leak to adjacent cells. 4A, when the scanning is performed as shown in FIG. 4A, the interval between the convergent beams l _{1 to} l ₄ is too large to obtain a high resolution, and the pinhole array 26 and the line sensor 30 are not obtained.
From the convergent beam l ₁ to
the distance between l ₄ may not be able to narrow further. In such a case, the scanning described with reference to FIG.

As described above, in this embodiment, the three-dimensional shape of the surface of the detection target 11 can be detected and inspected with high precision, high resolution, and high speed. When n condensed beams are used, if the moving speed of the detection target 11 in the Y direction is equal to that of the conventional three-dimensional shape detection device, the speed can be increased by n times. Then, by using the detection target 11 as an electronic circuit board, a wiring pattern or a soldered portion on the electronic circuit board is detected.
By comparing with the reference pattern data or the like, it is possible to accurately judge the quality of the wiring pattern or the soldered portion and detect the defect with high accuracy.

Although FIGS. 6 and 7 relate to the channel including the line sensor 30, the same applies to the other channels.

Next, a second embodiment of the three-dimensional shape inspection apparatus and pattern inspection apparatus and the method thereof according to the present invention will be described with reference to FIGS.

In the first embodiment, the object to be detected is irradiated with a convergent beam of a plurality of spot-like spots arranged on a straight line, and the reflected beam is detected as a detection beam by a line sensor. Although the three-dimensional shape and pattern of the inspection area of the detection target are inspected, the second
In this embodiment, a detection object is irradiated with a convergent beam of a plurality of sheet-like spots arranged on a straight line, and the reflected beam is used as a detection beam as TDI (Time Delay & Integrate).
(d: time delay integration type) The three-dimensional shape and pattern of the inspection area of the detection target are inspected by detecting with a sensor. As a result, the detection sensitivity can be increased, and even if a weaker illumination source is used,
This realizes a higher detection speed.

FIG. 8 is a block diagram showing the second embodiment, in which 56 is an illumination light source, 57 is a condenser lens,
58 is a pinhole, 59 is an illumination lens, 60 is a slit array, 61 is a beam splitter, 62 is an aperture stop, 6
3, 64, 65, 66 are slit arrays, 67, 68,
Reference numerals 69 and 70 denote TDI sensors, and the portions corresponding to those in FIG.

[0065] Figure 9 is similar to FIG. 2 for 1, a block diagram illustrating a (channels including TDI sensor 67) one channel detection system and the illumination system in FIG. 8 more specifically, 60 ₁ 60 _4, 63 ₁ to 63 ₄ are slit, the parts corresponding to FIG. 8 are denoted by like reference numerals. The illustration of the beam splitters 16 and 18 and the mirror 20 in FIG. 8 is omitted.

First, the illumination system in FIGS. 8 and 9 will be described.

The illumination light emitted from the illumination light source 56 is condensed by a condenser lens 57 and passes through a pinhole 58 disposed at a front focal position of the lens 57. Illumination light source 5
As 6, for example, a halogen light source can be used.
In addition, the pinhole 58 may be circular or rectangular. The illumination light beam passing through the pinhole 58 is converted into a parallel light beam by the illumination lens 59,
The light passes through four mutually parallel strip-shaped slits 60 ₁ , 60 ₂ , 60 ₃ , and 60 ₄ provided in the slit array 60,
A beam of a sheet-like spot parallel to each other (hereinafter, referred to as a sheet-like beam) is obtained from each.

FIG. 10 is a diagram showing a specific example of the slit array 60. Reference numeral 71 denotes a liquid crystal driver.
Are assigned the same reference numerals. A specific example of the slit array 60 is a liquid crystal slit. However, another configuration such as a slit array having a mechanical configuration may be used.

In the figure, a liquid crystal slit 60 is controlled by a control computer 51 via a liquid crystal driver 71, and has strip-like slits 60 ₁ , 60 ₂ , 60 ₃ , 60 arranged parallel to each other on a liquid crystal surface. Display ₄ .

In the first embodiment described above, it is necessary to adjust the mutual physical positional relationship between the microlens array 4 and the pinhole array 5 (FIGS. 1 and 2) and the line sensors 30 to 33. However, in this second embodiment, a liquid crystal slit is used as the slit array 60 instead of the microlens array, so that these slits 60 ₁ , 60 ₂ , 60 ₃ , 60 on the liquid crystal surface are provided. _Since the starting point position in ₄ can be set to an arbitrary position, the adjustment work between the illumination system and the detection system can be facilitated.

Returning to FIG. 8 and FIG.
The four sheet-like beams obtained in step 0 are turned back by the beam splitter 61 and pass through the stop 8, and then the objective lens 1
0, the convergent sheet beams l ₁ ′, l ₂ ′, l ₃ ′,
The light is focused on the inspection area on the detection target 11 as l ₄ ′. These convergent sheet beams l ₁ ′, l ₂ ′, l ₃ ′,
The sheet-like spot on the detection target 11 by l ₄ ′ is parallel to the moving direction (Y-axis direction) of the detection target 11, and the moving direction (Y-axis direction) of the detection target 11
Are arranged discretely at equal intervals in the direction (X-axis direction) perpendicular to the direction.

Next, the detection system (imaging system) in FIGS. 8 and 9 will be described.

The convergent sheet beams l ₁ ′, l ₂ ′, l ₃ ′, l
The reflection sheet-like beam from the object 11 to be detected by ₄ 'is converted into a parallel beam by the objective lens 10, and is formed by the aperture 8, the beam splitter 61 and the relay lens 14.
Through the aperture stop 62. The aperture stop 62 has a large numerical aperture only in a direction orthogonal to the longitudinal direction of the sheet-like spot of the reflection sheet-like beam.
The four reflecting sheet-like beams that have passed through the aperture stop 62 (hereinafter collectively referred to as a reflecting sheet-like beam group) are combined with the beam splitters 16 to 18 and the mirror in the same manner as in the first embodiment shown in FIG. By the optical system composed of 19-21, four reflection sheet beam groups L ₁ ′, L ₂ ′,
It is equally divided into L ₃ ′ and L ₄ ′. The reflection sheet-like beam group L ₁ ′ from the mirror 21 is the detection sheet-like beam group L
_{As 1} ′, the light is condensed by the imaging lens 22 and received by the TDI sensor 67 via the slit array 63, and the reflection sheet-like beam group L ₂ ′ from the beam splitter 18 is
The light is condensed by the imaging lens 23 as a detection sheet-like beam group L ₂ ′ and received by the TDI sensor 68 via the slit array 64, and the reflection sheet-like beam group L ₃ ′ from the mirror 19 becomes a detection sheet-like beam The group L ₃ ′ is condensed by the imaging lens 24, received by the TDI sensor 69 via the slit array 65, and
Reflecting sheet beams L ₄ from 'the detection sheet beams L _4' as, being condensed by the imaging lens 25,
The light is received by the TDI sensor 70 via the slit array 66.

The slit arrays 63, 64, 65,
The position of the detection target 11 conjugate to 66 is sequentially different. Here, the position of the detection target 11 conjugate with the slit array 63 is closest to the imaging lens 10, and the slit array 64,
It is assumed that the position of the detection target 11 conjugated in the order of 65 and 66 becomes farther from the imaging lens 10.

Here, as for the detection sheet-like beam group L ₁ ′, as shown in FIG.
, Four strip-shaped slits 63 ₁ , 63 ₂ , 63 ₃ , orthogonal to the longitudinal direction of the aperture stop 62 when viewed from the optical path of each detection sheet-like beam of the detection sheet-like beam group L ₁ ′.
63 ₄ are provided in parallel to each other.

The TDI sensor 67 has four light receiving sections 67 ₁ , 6
7 _2, 67 _3, 67 consists _{of four,} also each of the light receiving portion 67 _1,
67 _2, 67 _3, 67 _4, although not shown, and a plurality of cells (light receiving element). Then, the detection sheet-like beam corresponding to the convergent sheet-like beam l ₁ ′ in the detection sheet-like beam group L ₁ ′ is subjected to TD by the imaging lens 22.
The detection sheet-like beam condensed on the light receiving section 67 ₁ of the I sensor 67 and corresponding to the convergent sheet-like beam l ₂ ′ in the detection sheet-like beam group L ₁ ′ is converted by the imaging lens 22 into TDI.
Is focused on the light receiving portion 67 ₂ of the sensor 67, the detection sheet beams corresponding to the 'converging sheet beam l ₃ in' Detection sheet beams L ₁ is the imaging lens 22, the light receiving portion of the TDI sensor 67 67 ₃ is focused on the detection sheet beams corresponding to the 'converging sheet beam l ₄ in' detection sheet beams L ₁ is the imaging lens 22, focused on the light receiving portion 67 ₄ of the TDI sensor 67 Is done.

Here, the slits of the aperture stop 62 and the slit array 63 in FIG.
₁ ) will be described with reference to FIG.

In the figure, S is the spot of the convergent sheet beam l ₁ ′ on the object 11 to be detected. In this spot S, S ₀ is a spot when the convergent sheet beam l ₁ ′ converges on the inspection surface of the detection target 11,
ΔS is the convergence point of the convergent sheet beam l ₁ ′ is the detection target 1
This is an increased portion of the spot when it deviates from the inspection surface of No. 1.

The reflection sheet beam of the spot S is
When the light passes through the aperture stop 62, as described above, the aperture stop 6
No. 2 has a small numerical aperture NA in the longitudinal direction of the spot S,
Since the numerical aperture NA is large in the direction orthogonal to this,
Of the reflecting sheet-like beam passing through the aperture stop 62
G ′ is a convergence sheet for the inspection surface of the detection target 11.
Shaped beam l₁Δ increase amount according to the amount of displacement of the convergence point Δ
S becomes large. And such a spot S '
Slit 63₁ Through the slit 63₁Is a spot
S is convergent sheet beam l₁’Is the object to be detected
Spot S when coincident on 11 inspection surfaces₀ At the time
The size and shape must be such that only the detection sheet beam can pass.
Therefore, the increasing portion ΔS of the spot S ′ is
Slit 63₁ Removed by spot S₀ Is only T
The light is received by the light receiving section 67 of the DI sensor 67.
Therefore, a convergent sheet shape with respect to the inspection surface of the detection target 11 is provided.
Beam l₁'The convergence point position shift amount must be large
(Therefore, the inspection surface of the detection target 11 is₁
The more it deviates from the position conjugate to ₁To
Spot S passed₀Detection sheet beam light is low
Down. Therefore, this detection sheet beam cannot be detected.
As described later, in the inspection surface of the detection target 11,
Convergent sheet beam l₁'To detect the height of the irradiation position
You can do it.

Next, the operation of the TDI sensor 67 will be described with reference to FIG. Here, this TDI sensor 6
7, one light receiving section 67 ₁ will be described, but other light receiving sections 67 ₂ , 67 ₃ , 67 _{4 of} the TDI sensor 67 and other T
The same applies to each of the light receiving units of the DI sensors 68 to 70.

In the figure, to simplify the explanation,
The light receiving section 67 ₁ includes three cells a, b, and c, and S ₀ is a detection sheet-like beam that has passed through the slit 63 ₁ as shown in FIG. Of Y
Three points in the axial direction (FIG. 9) (hereinafter referred to as detection points)
And the amount of light reflected from the camera.

[0082] Therefore, now, 3 detection points X ₁ detection sheet beam S ₀ is the detection object 11 at time t _1, X _2, the amount of light reflected from X ₃ are each light receiving portion 67 ₁ of the cell a, b, c, and the amount of light received by cells a, b, and c at this time is X ₁ ,
X ₂ and X ₃ . At this time t ₁ , the received light amount X _{1 of the} cell a
Is transferred to the outside and the detection output X ₁
Is output as At the same time, in the light receiving section 67 ₁ ,
Receiving information of the received light amount X ₂ of the cell b is transferred to the cell a, the light-reception information relating to the received light amount X ₃ of the cell c is transferred to the cell b.

With the movement of the detection target 11 in the Y direction,
At time t ₂ , the detection sheet-like beam S ₀ is the detection target 1
This includes the amount of light reflected from the three detection points X ₂ , X ₃ , and X ₄ . The reflected light amounts from these three detection points X ₂ , X ₃ , X ₄ are received by cells a, b, c, respectively. Accordingly, in the cell a, the reflected light amount X ₂ received from the detection point X ₂ received at this time and the received light amount X ₂ transferred from the cell b are added, which is twice the reflected light amount X ₂ from the detection point X _2. is the information accumulated amount of light received 2X _2, Similarly, the cell b, 2 times the information of the received light quantity 2X ₃ of reflected light quantity X ₃ from the detection point X ₃ are accumulated. The cell c, the amount of reflected light X ₄ from the detection point X ₄ is received, equal information received light amount X ₄ in the reflected light quantity is accumulated. Thereafter, the level of the signal corresponding to the amount of light received 2X ₂ from the cell a is transferred to the outside, it is output as detection output 2X _2. Along with this, in the light receiving unit 67 _1, the received light amount 2X ₃ cells b
Receiving information is transferred to the cell a, the light-reception information of the light receiving amount X ₄ of the cell c is transferred to the cell b.

With the movement of the detection target 11 in the Y direction,
At time t _3, the detection sheet beam S ₀ is the detection object 11
Of the three detection points X ₃ , X ₄ , and X ₅ . The reflected light amounts from these three detection points X ₃ , X ₄ , X ₅ are received by cells a, b, c, respectively. Thus, the cell a, and the reflected light quantity X ₃ and light receiving quantity 2X ₃ transferred from the cell b from the detection point X ₃ that has received this time is added, three times the amount of reflected light X ₃ from the detection point X ₃ the accumulated information received light amount 3X ₃ is, likewise, to the cell b, 2 times the information of the received light quantity 2X ₄ of reflected light quantity X ₄ from the detection point X ₄ is accumulated.
The cell c receives the reflected light amount X ₅ from the detection point X ₅ ,
Information-same light receiving quantity X ₅ in the amount of reflected light is accumulated.
Thereafter, the level of the signal corresponding to the amount of light received 3X ₃ from the cell a is transferred to the outside, it is output as detection output 3X _3. Along with this, in the light receiving unit 67 _1, receiving information of the received light quantity 2X ₄ cells b is transferred to the cell a, the light-reception information relating to the received light quantity X ₅ cell c is transferred to the cell b.

Similarly, at time t ₄ , the detection sheet-like beam S ₀ includes the amounts of light reflected from the three detection points X ₃ , X ₄ , and X _{5 of the} detection target 11, and the cell of the light receiving section 671 a
3 times the information of the received light amount 3X ₄ of reflected light quantity X ₄ from the detection point X ₄ is accumulated in the amount of reflected light X ₅ from detection point X ₅ in cell b
Information twice the amount of light received 2X ₅ is accumulated, equal information received light amount X ₆ in reflected light quantity X ₆ from the detection point X ₆ in the cell c are accumulated, depending from the cell a to the amount of light received 3X ₄ levels signal is transferred to the outside, is output as detection output 3X _4.

In this way, light receiving information of a light receiving amount three times the amount of light reflected at each detection point of the detection target 11 is obtained from the cell a, and the detection sensitivity is greatly improved. Further, the adoption of the TDI sensor can compensate for the decrease in the light collection efficiency in the illumination system.

At times t ₁ and t ₂ in FIG.
_{Although the} detection output obtained from the cell a is lower than that after ₃ ,
This is a detection from the outside of the detection range of the detection target 11 as an initial operation of the detection operation, and is not a processing target by the height calculator 50 (FIG. 8).

Further, the pin according to the first embodiment described above is used.
As in the case of the hole arrays 26 to 29, the detection sheet
The beam is a slit for this in the slit array 63
To prevent light leaking from slits other than
In addition, the detection sheet beam that passed through the relevant slit
Are applied to the light receiving parts other than the light receiving part of the corresponding TDI sensor.
In order not to cause leakage light,
Convergent sheet beam l ₁’, L_Two’, L_Three’, L_Four’Spacing
And the interval between slits in the slit arrays 63 to 66
It goes without saying that it is set. In this case, the convergence sheet
Shaped beam l₁’, L_Two’, L_Three’, L_Four’
In the case where the detection resolution is reduced by the
Such a scanning method may be employed.

FIG. 14 shows the TDI sensors 67 to 67 in FIG.
FIG. 7 is a diagram schematically showing an arrangement relationship of 70 receiving units;
8 _{1-68 4} light receiving unit as described in Figure 13 of the TDI sensor 68, 69 ₁ to 69 ₄ is also the light receiving portion of the TDI sensor 69, 70 ₁ to 70 ₄ is also the light receiving portion of the TDI sensor 70, Parts corresponding to the above-mentioned drawings are denoted by the same reference numerals.

In the figure, the light receiving section 67 _{1 of} the TDI sensor 67, the light receiving section 68 _{1 of} the TDI sensor 68, and the TDI sensor 6
9 light receiving portion 70 ₁ of the light receiving portion 69 ₁ and the TDI sensor 70
Respectively receive a detection sheet-like beam corresponding to the same convergent sheet-like beam (here, a convergent sheet-like beam l ₁ ′ (FIG. 9)) of the reflection sheet-like beam group from the detection target 11, and TDI Light receiving section 67 _{2 of} sensor 67, TD
The light receiving portion 68 ₂ of the I sensor 68, the light receiving portion 69 ₂ of the TDI sensor 69, and the light receiving portion 70 ₂ of the TDI sensor 70 are respectively
A detection sheet-like beam corresponding to the same convergent sheet-like beam l ₂ ′ of the reflection sheet-like beam group from the detection target 11 is received, and the light receiving sections 67 ₃ and TDI of the TDI sensor 67 receive light.
Receiving portion 68 of the sensor 68 _3, TDI receiving portion 70 ₃ of the light receiving portion 69 ₃ and the TDI sensor 70 of the sensor 69 are each, the same converging sheet beam l ₃ of the reflecting sheet beams from the detection object 11 ' , The light receiving section 67 _{4 of} the TDI sensor 67, the light receiving section 68 _{4 of} the TDI sensor 68, and the light receiving section 69 _{4 of the} TDI sensor 69.
And the light receiving portion 70 ₄ of the TDI sensor 70 respectively, for receiving the detection sheet beam for the same converging sheet beam l ₄ 'of the reflecting sheet beams from the detection object 11.

Therefore, the height calculator 50 processes the detection output of the light receiving unit for receiving the detection sheet beam corresponding to the same convergent sheet beam in the TDI sensors 67 to 70, as in the first embodiment. By doing so, the detection target 1
The height of the detection point at which the convergent sheet beam is irradiated in step 1 is calculated. For example, FIG. 15 shows a method for obtaining the height of the detection point irradiated with the convergent sheet beam l ₁ ′ in FIG. 9, and the horizontal axis represents the sensor position (that is, the light receiving units 67 ₁ , 68). ₁ , 69 ₁ , 70 ₁ ), and the vertical axis represents the sensor output (ie, the light receiving sections 67 ₁ , 68 ₁ , 69 ₁ , 70 _1).
Of the light receiving sections 67 ₁ , 68 ₁ , 6
When the detected outputs of 9 ₁ and 70 ₁ are plotted and these plot points are interpolated by, for example, a Gaussian function, the characteristic shown by the broken line is obtained, and the sensor position taking the peak is irradiated with the convergent sheet beam l ₁ ′. This corresponds to the height of the detection point. Such processing is performed by the height calculator 50. The same calculation process is performed by the height calculator 50 for the light receiving unit that receives the detection sheet beam for the other convergent sheet beam, so that the other convergent sheet beams l ₂ ′ to l ₄ ′ are irradiated. The height of each detection point can be determined.

Also in the second embodiment, the number of convergent sheet beams irradiating the detection target 11 can be plural other than four, and the number of TDI sensors other than the above four can be plural. it can. However, it goes without saying that each TDI sensor has the same number of light receiving sections as the number of convergent sheet beams used. Further, the number of cells in the light receiving section of each TDI sensor may be a plurality other than the three shown in FIG. 13, and the detection resolution in the moving direction (Y-axis direction) of the detection target 11 is taken into consideration. You can decide.

As described above, also in this embodiment, the heights of a plurality of detection points of the detection target 11 can be simultaneously detected with high accuracy, and the detection speed can be increased.

Incidentally, also in the second embodiment, the leakage light from the slit arrays 63 to 66 and the TDI sensor 67
In order to prevent the light leakage at ~ 70, the above equation (2),
The condition shown in (3) must be satisfied.

Further, for example, the light receiving surfaces of the respective light receiving portions of the TDI sensors 30 to 33 are respectively located at the positions of the slit arrays 26 to 29 (that is, the light receiving surfaces of these light receiving portions are the TDI sensor 3).
16 so as to have a different conjugate positional relationship with the detection target object 11 for each of 0 to 33), and as shown in FIG.
In the I sensors 30 to 33, the width of each light receiving portion (width in the arrangement direction of the light receiving portions) is equal to the width of the slits in the slit arrays 26 to 29, and the non-light receiving portions shown by hatching between these light receiving portions. E may be provided, whereby each light receiving surface is also used as a slit of the slit arrays 26 to 29, so that these slit arrays 26 to 29 can be omitted. In this case, in order to prevent light leakage, it is necessary for the light receiving surface of each light receiving unit to satisfy the above expression (2). However, in the equation (2), the width of the light receiving unit (that is, the opening diameter of the light receiving unit) is q _P , and the pitch is also P. Equation (3) above does not matter.

FIG. 17 is a block diagram showing an embodiment of a pattern inspection apparatus and method according to the present invention.
Is an object to be detected, 73 is a height data memory, 74 is a computer for defect recognition, and 75 is pattern design position data. Parts corresponding to those in FIG.

In this embodiment, FIGS.
The defect of the pattern of the inspection object is inspected by using the height shape detection device described in FIG.
Can be used.

The inspection object is, for example, a wiring pattern of metal fine particles formed on a green sheet used for a ceramic substrate. Defects in the thickness direction of the wiring pattern include, for example, blurring, pinholes (insufficient height), and protrusions (excessive height). Of course, the object to be inspected is not limited to this, and the present invention can also be applied to inspection of a thickness direction defect in a copper wiring pattern formed on a printed board, a soldered portion of the printed wiring board, and the like.

In FIG. 17, the inspection object 72 as described above is fixed to the XY stage 12 via the work holder 13. The height data of the inspection area of the inspection object 72 calculated by the height calculator 50 as described with reference to FIGS. 8 to 16 is sequentially stored in the height data memory 73. The defect recognition computer 74 reads the height data and the pattern design position data 75 stored in the height data memory 73 under the control of the control computer 51, and based on these data, the inspection object 72. Defect determination processing of the wiring pattern on the green sheet is performed. The inspection result is displayed on a display device (not shown), and the user can know the presence or absence of the defect and its cause by viewing the result.

[0100]

As described above, according to the present invention,
Since a plurality of detection points of an object to be detected are simultaneously detected using a line sensor as a detector, a three-dimensional shape can be detected with high detection accuracy and high detection speed by eliminating blind spots.

According to the present invention, a plurality of detection points of an object to be detected are simultaneously detected by using a TDI sensor as a detector, so that the detection sensitivity can be further improved and the illumination system can be improved. Can be compensated for the decrease in light-collecting efficiency at

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a three-dimensional shape detection device and method according to the present invention.

FIG. 2 is a configuration diagram showing one channel of a detection system and an illumination system in FIG. 1;

FIG. 3 is a diagram schematically showing an arrangement relationship of cells of the line sensor in FIG. 1;

FIG. 4 is a diagram showing a specific example of a height calculating method by a height calculator in FIG. 1;

FIG. 5 is a diagram illustrating a method of scanning the inspection object using a convergent beam in the first embodiment illustrated in FIG. 1;

FIG. 6 is a diagram showing a state of a detection beam in a line sensor when the height of a detection target in FIG. 1 changes.

FIG. 7 is a diagram showing a state in a pinhole array of detection beams with respect to two adjacent convergent beams applied to portions having different heights on the detection target in FIG. 1;

FIG. 8 is a configuration diagram showing a second embodiment of a three-dimensional shape detection device and method according to the present invention.

9 is a configuration diagram showing one channel of a detection system and an illumination system in FIG. 8;

10 is a diagram illustrating a specific example of a liquid crystal slit in FIG.

11 is a diagram showing a main part of the detection system in FIG. 9 for one channel.

FIG. 12 is a view for explaining the operation of the slit array in FIG. 9;

FIG. 13 is a diagram for explaining the operation of the TDI sensor in FIG. 9;

FIG. 14 is a diagram schematically showing a specific example of an arrangement relationship of light receiving units of the TDI sensor in FIG. 8;

FIG. 15 is a diagram illustrating a specific example of a height calculation method by the height calculator in FIG. 8;

FIG. 16 is a diagram schematically showing another specific example of the arrangement relationship of the light receiving units of the TDI sensor in FIG. 8;

FIG. 17 is a configuration diagram showing an embodiment of a pattern inspection apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Laser light source 2 Beam expander 3 Cylindrical lens 4 Micro lens array 5 Pinhole array 6 Collimating lens 7 Polarization beam splitter 8 Aperture 9 1/4 wavelength plate 10 Objective lens 11 Detected object 12 XY stage 13 Work holder 14, 15 Relay lens 16-18 beamsplitter 19 to 21 mirror 22-25 forming lens 26-29 pinhole array 26 _{1-26 4} pinhole 30 to 33 the line sensor 30 _to 333 ₄ cells (light receiving element) 34 to 37 amp. 38 41 A / D converter 42-45 Shading correction circuit 46-49 Image memory 50 Height calculation circuit 51 Control computer 52 Stage control board 53 Driver 54 Camera control board 55 Optical system 56 Illumination light source 57 Condenser 58 58 Pinhole 59 Irradiation lens 60 Liquid crystal array 61 Beam splitter 62 Opening 63 to 66 Slit array 67 to 70 TDI sensor 67 ₁ to 704 ₄ Light receiving unit 71 Liquid crystal driver 72 Inspection object 73 Height data memory 74 Defect recognition computer 75 Pattern design position data

Continued on front page F-term (reference) 2F065 AA24 AA53 BB02 BB05 CC01 DD00 DD05 DD06 EE00 FF01 FF10 FF42 FF49 GG04 HH04 HH05 HH08 HH13 JJ01 JJ05 JJ09 JJ25 LL04 LL08 LL09 LL10 LL12 LL12 LL12 LL12 LL12 LL12 LL12 LL28 QQ29 QQ32

Claims (6)

[Claims] An illumination means for irradiating a detection object with a convergent beam of n spots (where n is an integer of 2 or more) linearly and discretely arranged, and detecting the convergent beam. M reflected beam groups consisting of n reflected beams from the object (where m is an integer of 2 or more)
Optical means for equally dividing the reflected beam group into a plurality of reflected beam groups, provided for each of the reflected beam groups divided by the optical means;
M imaging lenses that form an image of the n reflected beams of the reflected beam group as detection beams; and n detection beams provided for each of the imaging lenses and formed by the imaging lens. Processing m line sensors with n cells that receive light separately, and processing the detection output of each of the m line sensors;
Height calculating means for simultaneously calculating the heights of the n irradiation points on which the convergent beam is irradiated on the detection target, wherein the detection target is conjugate with the m line sensors Are arranged so that the position of each line sensor is different for each of the line sensors. The height calculating means calculates the optical means from the same reflected beam from the detection object at the m line sensors. A three-dimensional shape detecting apparatus for calculating a height of an irradiation point of the convergent beam on the detection target object by processing a light receiving amount of a cell that receives each detection beam divided by the detection beam. 2. A sheet-like n-shaped (where n is an integer of 2 or more) spot shape arrayed in a direction perpendicular to the direction of movement of the detection object, with the movement direction of the detection object being a longitudinal direction. Illuminating means for irradiating the detection object with the convergent sheet beam; and reflecting sheet beams from n detection points of the detection object irradiated with the convergent sheet beam as a reflection sheet beam group An aperture stop having a small numerical aperture in the longitudinal direction of the reflective sheet-like beam and having a large numerical aperture in the width direction of the reflective sheet-like beam, and allowing the reflected beam group to pass through the aperture; An optical unit that divides the reflection sheet-like beam group that has passed through the aperture of the stop into m pieces (where m is an integer of 2 or more) to form m reflection sheet-like beam groups; M divided reflective sheets M imaging lenses provided for each beam group, for imaging the n reflection sheet beams of the reflection sheet beam group as detection sheet beams, and m imaging lenses provided for each imaging lens. M TDI sensors provided with n light receiving units for separately receiving the n detection sheet beams formed by the image lens, and detecting outputs of the m TDI sensors for each of the light receiving units And height calculating means for calculating simultaneously the heights of the n irradiation points on which the convergent sheet-shaped beam is irradiated on the detection object, and the m TDI sensors The light receiving sections of the TDI sensor have k (where k is an integer of 2 or more) cells, and the same detection is performed as the cells of the light receiving sections. A sheet-like beam is incident, and the received light information is sequentially transferred between the cells. The amount of reflected light from the same detection point of the detection target is integrated, and the height calculation means calculates the same reflection sheet-like beam from the detection target by m m TDI sensors. Calculating the height of the irradiation point of the convergent sheet-like beam on the detection target by processing the amount of light received by the light-receiving unit that receives the respective detection sheet-like beams divided by the optical unit. A three-dimensional shape detection device characterized by the above-mentioned. 3. A system comprising n reflected beams obtained by irradiating a convergent beam of n spot-like spots (where n is an integer of 2 or more) linearly and discretely arranged on a detection target. The reflected beam group is equally divided into m (here, m is an integer of 2 or more) detection beam groups each including n detection beams, and the detection beam group corresponding to the line sensor provided for each detection beam group is obtained. The detection beam group is collected and received, and the m line sensors have n cells, and the positions of the conjugated detection target are different from each other. The detection output of each of the cells receiving the detection beam divided from the same reflection beam is collectively processed, and the height of the irradiation point of the convergent beam of the detection object from which the reflection beam is obtained is determined. By calculation, the n convergent beams of the object to be detected are calculated. A three-dimensional shape detection method, wherein a height of an irradiation point is detected at the same time. 4. A spot-shaped n-shaped spot (where n is an integer of 2 or more) arranged in a direction perpendicular to the direction of movement of the detection object, with the movement direction of the detection object being a longitudinal direction. Irradiating the object to be detected with a convergent sheet beam of
The convergent sheet-like beam is irradiated with a reflection sheet-like beam group consisting of a sheet-like reflection sheet-like beam having a spot shape from each of the n detection points of the detection object. Passing through an opening having a large numerical aperture in the width direction with respect to the direction, dividing the reflection sheet-like beam group having passed through the opening into m pieces (where m is an integer of 2 or more), and n pieces each. M detection beam groups composed of the detection sheet beams of the above, and the detection sheet beam groups corresponding to the TDI sensors provided for each of the m detection sheet beam groups are condensed and received. Each of the TDI sensors has n light receiving sections for separately receiving the n detection sheet beams of the same corresponding detection sheet beam group, and the positions of the conjugated detection target objects are different from each other. The light receiving units are respectively By having k (where k is an integer of 2 or more) cells, the same detection sheet-like beam is incident on the k cells, and the received light information is sequentially transferred between the cells. The amount of light received by the reflective sheet-like beam from the same detection point of the detection target is integrated, and each of the m-type TDI sensors receives the detection sheet-like beam divided from the same reflective sheet-like beam. By processing the detection output of the cell and calculating the height of the detection point of the detection target, the height of the n detection points irradiated with the convergent sheet beam on the detection target is calculated. A three-dimensional shape detection method, wherein the three-dimensional shape is detected simultaneously. 5. A pattern inspection apparatus using the three-dimensional shape detection device according to claim 1, wherein a pattern is formed on a surface of the detection target, and the pattern is obtained by the height calculation unit. A pattern inspection apparatus comprising: a defect detection unit configured to detect a defect of the pattern based on height information of a surface of the detection target. 6. A pattern inspection method using the three-dimensional shape detection method according to claim 3, wherein a pattern is formed on a surface of the detection target, and the calculated surface of the detection target is calculated. A pattern detecting method for detecting a defect of the pattern based on height information of the pattern.