JPH09329422A - Height measuring method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make accurate measurement of the height of an object with respetct to the reference value. SOLUTION: An X-Y-Z stage 40 is moved so that an image formed on the light receiving surface of a CCD is converged at three points on the plane S of an object to be measured 41, and the coordinates for the position of the stage 40 when convergence is established are determined, followed by determination of the plane S in which the three points exist, and a light spot is formed on the object 41 by a projecting/sub-scanning part 50, and the height H of the light spot is sensed on the basis of the output from sensing of the light spot made by a light position sensor 62 while the object 41 is photo-scanned by an acoustic-optical deflector 52 and the stage 40, and the obtained height H is put in correspondence to the position of the stage 40 at the time an output is given from the sensing so that H is converted into the height over the plane S. The height of the light spot when light spot formed on the object by the part 50 is sensed by a light spot sensor 62 in the converged condition is put in correspondence to the converging position of the object 41.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a height measuring method and apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 8, in a multi-chip module, semiconductor chips 11 to 15 are bonded on a substrate 10 via a bump array. The metal bumps 21 to 24 having a low melting point and a low resistance are a part of the bump array on the semiconductor chip 11. As shown in FIG. 9A, the bump 21
24 are pads 31 formed on the semiconductor chip 11.
To 34. There is variation in the height of the bumps 21 to 24 with respect to the surface S of the semiconductor chip 11, and if this variation is large, defective bump bonding to the pads formed on the substrate 10 occurs. Since the bump array has thousands of bumps arranged in a grid, a bump height measuring device capable of automatic measurement is required.

As shown in FIG. 9B, when the height of the bump with respect to the surface S0 determined by the arrangement of the optical system is measured, when the surface S of the semiconductor chip 11 is inclined with respect to the surface S0, the bump height is increased. Measurements will be inaccurate. Therefore, conventionally, as shown in FIG. 9C, the height of the wiring pattern 35 formed on the semiconductor chip 11 is used as a reference height, and the bump height is measured by the same method. That is,
The height of the wiring pattern 35 was measured by making a light beam incident on the surface S at an incident angle of 45 ° and focusing the reflected light on a light position detector (PSD).

[0004]

However, when the bump diameter is 50 to 100 μm, the bump pitch is 150 to 2 μm.
Since it is 00 μm, a part of the light flux incident on the wiring pattern 35 is blocked by the bump, and the light reflected by the bump is PSD.
Imaged above. Since the position of the center of gravity of the image on the PSD is detected by the PSD, the height measurement value of the wiring pattern 35 becomes accurate, and as a result, the bump height measurement value becomes inaccurate.
This problem is solved by forming a reference pattern at a position apart from the bump on the semiconductor chip and measuring the height thereof. However, depending on the semiconductor chip, it may not be possible to form the reference pattern at such a position.

There is also a method in which light is vertically incident on the surface S and the light diffracted in an oblique direction is imaged on the PSD to measure the height. However, since the specularly reflected light on the bump is incident on the PSD. , The dynamic range of the incident light intensity of the PSD is widened and the height measurement accuracy is lowered. In view of such problems, an object of the present invention is to provide a height measuring method and device capable of measuring the height of an object with respect to a reference height with higher accuracy.

[0006]

In the height measuring method according to the first aspect of the present invention, a moving stage on which an object is mounted and which can be moved three-dimensionally, and a light source light obliquely directed onto the object. , A light projecting means for converging and irradiating the object, an optical scanning means for scanning the object with the converging and irradiating light on the object, an optical position detector, and a reflected light from the object for the light position. A light position detecting means including a first optical system for forming an image on the light receiving surface of the detector, an image pickup element, and a first for forming an image of an object on the moving stage on the light receiving surface of the image pickup element. Two
And a reference height determining means including an optical system, so that an image formed on the light receiving surface of the image pickup element is focused at each of n points (n ≧ 3) on the surface of the object. While moving the moving stage, the position coordinates of the moving stage when focused are obtained, the surface S on which the point of the position coordinates obtained for the n points is substantially present, and the optical scanning means performs the scanning. Detecting the height H of the light spot based on the output of the light position detector when the light spot formed on the object by the light projecting means is detected by the light position detector, Sa H
The height H is converted to the height from the surface S in correspondence with the position of the moving stage at the time of the output.

According to the first aspect of the present invention, the height measurement value of the reference surface S of the object becomes accurate by focusing from directly above the object, and the height of the object with respect to the reference surface S on which the protrusion is formed is increased. It has an effect that it is possible to measure the height more accurately than before, and contributes greatly to the improvement of the quality of the height inspection of the protrusion, for example, the bump on the semiconductor chip.

In the first aspect of the first aspect of the invention, after designating the position of the n point on the design pattern of the object and performing the focusing, the actual pattern imaged by the image sensor and the design pattern Pattern matching is performed, and the moving stage is driven so that the designated position on the design pattern coincides with the position on the actual pattern based on the positional shift between both patterns.

According to the first aspect, it is possible to automatically focus on an accurate position on the object. In the second aspect of the first invention, the moving stage is an XYZ stage, and the moving stage is moved in the Z direction so that the image formed on the light receiving surface of the image sensor is focused. , The surface S is expressed by the formula aX
+ BY + cH = d, where a to d are constants and the height of the light spot from the surface S is obtained.

According to the second aspect, the height of the object with respect to the surface S can be easily obtained. In the height measuring method according to the second aspect of the invention, a moving stage on which an object is mounted and which can be moved three-dimensionally, a light projecting unit for converging and irradiating the object with light source light from an oblique direction, and on the object. A light scanning means for scanning the light that is convergently irradiated on the object onto the object, an optical position detector, and a first for forming reflected light from the object on the light receiving surface of the optical position detector. A reference height determining unit including an optical position detecting unit including an optical system, an image sensor, and a second optical system for forming an image of an object on the moving stage on a light receiving surface of the image sensor. , Is used to move the moving stage so that the image of the object formed on the light receiving surface of the image sensor is focused, and in the focused state, the light formed on the object by the light projecting means. The optical point based on the output of the optical position detector when the point is detected by the optical position detector By detecting the reference height H0 height H,
The relationship between the focus position of the object and the output of the optical position detector is associated.

According to the second aspect of the invention, the reference height position measurement value of the target object becomes accurate by focusing from directly above the target object, and the height of the target object on which the protrusion is formed with respect to the reference position is conventionally measured. This has the effect of enabling more accurate measurement. In the first aspect of the second invention, the object for performing the focusing has a striped pattern of a light absorbing portion and a light reflecting portion formed on the surface thereof, and the control / processing means includes When the difference between the maximum value and the minimum value of the brightness of the output image is maximum, it is determined that the focus is completed.

According to the first aspect, since the focusing is performed with high accuracy, the measured reference position becomes accurate,
As a result, the height accuracy with respect to the reference position is improved. Third
In the height measuring device according to the present invention, a moving stage on which an object is mounted and which can be moved three-dimensionally, a light projecting unit for converging and irradiating a light source light from an oblique direction onto the object, and a focusing stage on the object. Optical scanning means for scanning the irradiated light on the object, an optical position detector, and a first optical system for forming an image of reflected light from the object on the light receiving surface of the optical position detector. A light position detecting unit including: an image pickup device; and a second image pickup device for forming an image of an object on the moving stage on a light receiving surface of the image pickup device.
A reference height determining unit having an optical system and a control / processing unit are provided, and the control / processing unit has the image pickup device for each of n points (n ≧ 3) on the surface of the object. The moving stage is moved so that the image formed on the light receiving surface of the lens is focused, the position coordinate of the moving stage when focused is obtained, and the surface S on which the point of the position coordinate obtained for the n points is substantially present While performing the scanning with the optical scanning means,
The height H of the light spot is detected based on the output of the light position detector when the light spot formed on the object by the light projecting means is detected by the light position detector, and the height H is detected. H is made to correspond to the position of the movable stage at the time of the output, and the height H is made to correspond to the surface S
Convert to height from.

In the first aspect of the third invention, the reference height determining means is disposed in the optical path of the first optical system, the light source, the collimator for collimating the light emitted from the light source, and the collimator. A half mirror that reflects a part of the light that has passed through the collimator, and the light reflected by the half mirror is focused and irradiated onto the object.

In the second aspect of the third aspect of the invention, the design pattern storage means in which the design pattern data of the object is stored, the actual pattern storage means in which the image picked up by the image pickup device is stored, and the parameter storage means. And a console having a display device and a position designating means, and the control / processing means causes the display device to display the design pattern based on the contents of the first storage means, and the display device The designated position by the position designating means displayed on the design pattern is stored in the parameter storing means as the position of the n point, and after the focusing is performed, the actual pattern stored in the actual pattern storing means And the design pattern stored in the design pattern storage means are subjected to pattern matching, and the designated position on the design pattern is determined based on the positional deviation of both patterns. Driving the movable stage so as to match the position on the pattern.

In the third aspect of the third aspect of the invention, the moving stage is an XYZ stage, and the moving stage is moved in the Z direction so that the image formed on the light receiving surface of the image pickup device is focused. Direction, and the control / processing means obtains the surface S in the form of the expression aX + bY + cH = d, where a to d are constants and the height of the light spot from the surface S is obtained.

In the height measuring apparatus according to the fourth aspect of the invention, a movable stage on which an object is mounted and which is movable three-dimensionally, a light projecting means for converging and irradiating the object with the light source light from an oblique direction, An optical scanning means for scanning the light that is convergently radiated onto the object, an optical position detector, and an image of reflected light from the object on the light receiving surface of the optical position detector. A first optical system, an optical position detecting means, and an image sensor,
It has a reference height determination means having a second optical system for forming an image of an object on the moving stage on the light receiving surface of the image pickup element, and a control / processing means, and the control / processing means , The moving stage is moved so that the image of the object formed on the light receiving surface of the image sensor is focused, and in a focused state, the light spot formed on the object by the light projecting unit is By detecting the height H of the light spot as the reference height H0 based on the output of the light position detector when it is detected by the light position detector, the focus position of the object and the light position detector Correlate the relationship with the output.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a height measuring device. An object 41 is mounted on an XYZ stage 40, and a light projecting / sub-scanning unit 50 and a height detecting unit 60 are provided above the target 41.
And the reference height determination unit 70 is arranged. Object 41
Is the semiconductor chip 11 of FIG. 8 or the reference plate 4 of FIG.
2.

In the light projecting / sub-scanning unit 50, the parallel light beam emitted from the laser 51 is converted into an acousto-optic deflector (AOD) 52.
Is deflected and scanned in the direction perpendicular to the paper surface (CW direction in FIG. 4A), passes through the lenses 53 and 54 and the objective lens 55, and is perpendicular to the paper surface on the object 41 (Y direction in FIG. 4A).
To be scanned. All of L1, L2 and L3 in FIG. 4A are optical path center lines.

In the height detector 60, the light flux reflected by the surface S passes through the objective lens 61A and the imaging lens 61B and is enlarged and imaged on the light receiving surface of the optical position detector (PSD) 62.
In the reference height determining unit 70, the light emitted from the illumination light source 71 is collimated by the collimator lens 72, a part of which is bent by 90 ° by the half mirror 73, passes through the objective lens 74, and passes through the surface S of the object 41. Is focused and irradiated. The reflected light from the surface S passes through the objective lens 74 and is substantially collimated, and a part thereof passes through the half mirror 73, passes through the imaging lens 75, and is enlarged and imaged on the CCD 76.

The components of the light projecting / sub-scanning unit 50, the height detecting unit 60, and the reference height determining unit 70 are fixed during use except for vibration of the acousto-optic deflector. FIG. 2 is a block diagram showing a circuit portion of the device of FIG. Optical position detector 6
The currents I1 and I2 output from one end and the other end of 2 are supplied to the height calculation circuit 80, and the height calculation circuit 80
Normalized height of upper light spot (I1-I2) / (I1 +
I2) is calculated, and the digitized result is supplied to the height memory 81 as the height H.

Here, when the acousto-optic deflector 52 is in the non-operating state, the locus of the light spot formed on the surface S by the light projecting / sub-scanning unit 50 is the main scanning line L shown in FIG. 6 (B). The XYZ stage 40 is driven so that The sub-scanning direction of the light spot when the acousto-optic deflector 52 is driven is the Y direction perpendicular to the main scanning line L. The light spot position on the surface S is determined by the position of the XYZ stage 40 and the driving amount of the acousto-optic deflector 52.

The position of the XYZ stage 40 is controlled by the stage control circuit 82, and the position is detected by the stage control circuit 82 and supplied to the address calculation circuit 84.
The acousto-optic deflector 52 is driven by the AOD drive circuit 83, and the scanning position information included in the drive signal is supplied to the address calculation circuit 84. The address calculation circuit 84
The storage address of the height H is calculated based on these input values, and the height memory 81 is addressed.

The output of the CCD 76 is amplified in an image input circuit 85, separated into a video signal and a synchronizing signal, a luminance signal is digitized, a storage address is obtained based on the synchronizing signal, and an image is stored in a frame memory 86. Is stored. CAD data of the wiring pattern on the semiconductor chip 11 is stored in the external storage device 87, which is read and written in the frame memory 88. The data stored in the height memory 81, the frame memories 86 and 88, and the parameter memory 89 are processed by the processing device 90. As will be described later, the processing device 90 includes a height calculation circuit 80.
The height H is received as necessary from the above, and a command is given to the stage control circuit 82 and the AOD drive circuit 83. A console 91 for interactively giving instructions to the processing device 90 is connected to the processing device 90.

Next, the height measuring method will be described with reference to FIG. First, the CAD data of the uppermost wiring pattern (including lands and pads) of the semiconductor chip 11 is read from the external storage device 87 and written in the frame memory 88,
The pattern is displayed on the screen of the console 91. The scanner sees this screen and designates three points Q1, Q2, and Q3 in the wiring pattern on the semiconductor chip 11 which are separated from each other with a mouse, as shown in FIG. 6A. The coordinates of the designated points Q1, Q2, and Q3 are stored in the parameter memory 89 via the processing device 90. In FIG. 6A, only a pattern including points Q1 to Q3 is shown and simplified.

(A1) Based on the instruction displayed on the screen of the console 91, as an object 41 as an object 41 on the XYZ stage 40 and below the reference height determining section 70, FIG.
The reference plate 42 shown in FIG. Processor 90
In response to this, drives the XYZ stage 40 in the Z-axis direction to focus the image of the reference plate 42 on the CCD 76.

On the reference plate 42, an absorbing portion and a reflecting portion, for example, a black and white striped pattern are formed.
The hatched portion in (A) is an absorbing portion. With respect to the image of the reference plate 42 stored in the frame memory 86, the brightness B within the range of Y1 ≦ Y ≦ Y2 for each position X.
The Y-axis direction integrated value of (X, Y), that is, the X-axis projection brightness BX is obtained by the processing device 90. When the XYZ stage 40 is driven from one end to the other end within a predetermined range in the Z-axis direction, the X-axis projected brightness BX is as shown in FIG.
It changes to (C), (D), (C), and (B). FIG.
The focusing is performed by stopping the XYZ stage 40 at the Z-direction position where the difference between the maximum value and the minimum value of the X-axis projection brightness BX becomes the maximum as in (D).

Since the focusing is performed with high accuracy by such focusing, the formula of the surface S obtained as described later becomes accurate, and the accuracy of minute bump height measurement on the surface S is improved. In this state, the processing device 90 turns off 71, turns on 51, and sets the height H when the light is projected on the reflecting portion of the reference plate 42 to H0, which is read from the height calculation circuit 80 and stored in the parameter memory 89. FIG.
(B) is the Z direction positions Z0 and Z01 of the reference plate 42.
And Z02 and the image forming positions P0, P1 and P2 on the optical position detector 62 of the light spot on the surface S are shown. The imaging lens 61 includes the objective lens 61A and the imaging lens 6 shown in FIG.
1B and 1B are collectively shown.

(A2) Based on the instruction displayed on the screen of the console 91, the semiconductor chip 11 is mounted as an object 41 on the XYZ stage 40, and the console 91 is installed.
Gives a preparation completion instruction to the processing device 90. In response to this, the processing device 90 drives the XYZ stage 40 so that the optical axis of the reference height determination unit 70 passes through the point Q1 on the semiconductor chip 11. At this position, the image near the point Q1 is focused on the CCD 76 in the same manner as in step A1, and the Z-direction position Z of the XYZ stage 40 at this time is adjusted.
1 is read from the stage control circuit 82 and stored in the parameter memory 89.

After focusing, the actual image of the wiring pattern portion on the frame memory 86 and the frame memory 8 are displayed.
Position matching is performed by performing pattern matching with the wiring pattern design image on 8 and driving the XYZ stage 40 so that the point Q1 on the design pattern matches the point Q1 on the actual pattern. Then, after that, the focus may be automatically refocused to an accurate position on the semiconductor chip 11.

Similarly to the point Q1, the points Q2 and Q3 are the Z-direction positions Z2 and Z of the XYZ stage 40.
The value of 3 is read and stored in the parameter memory 89.
In the next scanning of the XYZ stage 40 in step A3, the position of the XYZ stage 40 in the Z direction is changed to the point Q3.
It is fixed at the Z-direction position Z3 when focused at (X3, Y3, Z3).

(A3) On the semiconductor chip 11, the acousto-optic deflector 52 is periodically driven while the XYZ stage 40 is driven along the main scanning line L shown in FIG. 6B. Scan the entire surface. As a result, the bump height H on the semiconductor chip 11 is written in the height memory 81. The bump tops 21T to 24T shown in FIG. 7B are X- of the height H of the bumps 21 to 24 shown in FIG. 7A, respectively.
The Z section is shown. The height H is the height from the surface S0 determined by the arrangement of the light projecting / sub-scanning unit 50 and the height detecting unit 60.

(A4) The formula of the surface S passing through the three points of Z = Z1 to Z3 at the points Q1 to Q3 on the XY plane is obtained,
As shown in FIG. 7C, the bump top portion 2 with the surface S as a reference
The heights h1 to h4 of the vertices of 1T to 24T are obtained as bump heights. The expression of the surface S can be made into a form of aX + bY + cH = d (1) using the relational expression of the height Z and the height H. Here, a to d are constants.
Since the surface S passes through the point Q3, the expression (1) is aX3 + bY3 +.
cH0 = d is satisfied.

In FIG. 7C, the angle between the surface S and the surface S0 is usually small, and therefore the surface S is approximately approximated for simplification.
Instead of calculating the bump height perpendicular to, the bump height in the Z direction may be obtained from the surface S. In this case, the point (X1, Y1, H11) on the top of the bump and the point (X1, Y1, H11) on S
10) correspond, H11-H10 are in position (X
1, Y1) is the bump height.

In this way, the surface S of the semiconductor chip 11 is
The bump height based on is measured more accurately than before,
Based on this height data, the bump height inspection can be performed more accurately than before. The present invention also includes various modified examples. For example, the height H0 may be determined using a predetermined pattern on the semiconductor chip 11 without using the reference plate 42.

The optical position detector 62 only needs to be able to detect the height position, and for example, a line sensor is also included in the optical position detector. The optical deflector is not limited to the acousto-optic deflector 52, and may be a configuration using a polygon mirror, a galvano mirror, or the like. In step A2 of FIG. 3, the focus Z coordinates Z1 to Z3 are measured for three points Q1 to Q3, but the same is applied to four points or more, and in step A4, the least squares method, that is, these points and the surface S The surface S may be obtained so that the total sum of squares of the distance is minimized. FIG.
The step A1 may be omitted, and only the variation in the bump height measurement value may be obtained (the height from a plane parallel to the plane S may be obtained).

The object to be measured may be a protrusion other than the bump.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an optical system of a height measuring device according to an embodiment of the present invention.

2 is a block diagram showing a circuit portion of the device of FIG. 1. FIG.

FIG. 3 is a bump height measurement flowchart using the apparatus of FIG.

4A is an explanatory diagram of optical scanning, and FIG. 4B is an explanatory diagram of determining a reference position on a PSD.

FIG. 5 is an explanatory view of focusing on a reference plate.

FIG. 6A shows focus position points Q1 to Q on the chip.
3A and 3B are diagrams for explaining on-chip scanning.

FIG. 7 is an explanatory diagram of a bump height measuring method.

FIG. 8 is a perspective view of a multi-chip module using a bump array.

FIG. 9 is a diagram illustrating a problem of the conventional technique.

[Explanation of symbols]

 11 Semiconductor Chips 21-24 Bumps 21T-24T Bump Tops S, S0 Surfaces 31-34 Pads 35, 91-93 Wiring Pattern 40 XYZ Stage 41 Object 42 Reference Plate 50 Light Projection / Sub-scanning Section 51 Laser 52 Acousto-optic deflector 53, 54 Lens 55, 61A, 74 Objective lens 60 Height detection unit 61B, 75 Imaging lens 62 Optical position detector 70 Reference height determination unit 71 Light source 72 Collimator lens 73 Half mirror 76 CCD

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mitaka Oshima, Inventor Mitaka Oshima 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Yoji Nishiyama, 4-chome, Ueda-tanaka, Nakahara-ku, Kawasaki, Kanagawa 1-1 No. 1 inside Fujitsu Limited (72) Inventor Takashi Fuse 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Inside Fujitsu Limited

Claims (10)

[Claims] 1. A moving stage on which an object is mounted and which can be moved three-dimensionally, a projecting means for converging and irradiating the object with light source light from an oblique direction, and light converging and irradiating on the object. An optical scanning means for scanning the object on the object, an optical position detector, and a first optical system for forming an image of reflected light from the object on the light receiving surface of the optical position detector. The optical position detecting means, the image pickup element, and the reference height determining means having the second optical system for forming an image of the object on the moving stage on the light receiving surface of the image pickup element are used. For each of n points (n ≧ 3) on the surface of the object, the moving stage is moved so that the image formed on the light receiving surface of the image pickup element is focused, and the position coordinate of the moving stage when focused is calculated. The surface S on which the point of the position coordinate obtained for the n point is substantially present
Based on the output of the light position detector when the light position detector detects a light spot formed on the object by the light projecting device while performing the scanning by the light scanning device. The height H of the light spot is detected, the height H is made to correspond to the position of the moving stage at the time of the output, and the height H is converted to the height from the surface S. Characteristic height measurement method. 2. The position of the n point is designated on the design pattern of the object, the focus is performed, and then the pattern matching between the real pattern imaged by the imaging device and the design pattern is performed, The height measuring method according to claim 1, wherein the moving stage is driven so that a designated position on the design pattern coincides with a position on the actual pattern based on a positional shift of the pattern. 3. The moving stage is an XYZ stage, and a direction in which the moving stage is moved so that an image formed on a light receiving surface of the image sensor is focused is a Z direction, and the surface S Is calculated in the form of aX + bY + cH = d, where a to d are constants, and the height of the light spot from the surface S is calculated. . 4. A moving stage on which an object is mounted and which can be moved three-dimensionally, a projecting means for converging and irradiating the object with light source light obliquely, and light converging and irradiating on the object. An optical scanning means for scanning the object on the object, an optical position detector, and a first optical system for forming an image of reflected light from the object on the light receiving surface of the optical position detector. The optical position detection means, the image pickup element, and the reference height determination means including the second optical system for forming an image of the object on the moving stage on the light receiving surface of the image pickup element are used. The moving stage is moved so that the image of the object formed on the light receiving surface of the element is focused, and in the focused state, the light spot formed on the object by the light projecting means is detected by the optical position. The height H of the light spot is based on the output of the optical position detector when it is detected by the detector. By detecting as H0, associating the relationship between the output of the focus position and the optical position detector of the object, the height measuring method characterized by. 5. The object for performing the focus has a striped pattern of a light absorbing portion and a light reflecting portion formed on the surface thereof, and the control / processing means sets the brightness of an output image of the image sensor. The height measuring method according to claim 4, wherein the focus is determined to be completed when the difference between the maximum value and the minimum value of is maximum. 6. A moving stage on which an object is mounted and which is movable three-dimensionally, a projecting means for converging and irradiating the object with light source light from an oblique direction, and light converging and irradiating on the object. An optical scanning means for scanning the object on the object, an optical position detector, and a first optical system for forming an image of reflected light from the object on the light receiving surface of the optical position detector. A reference height determining means including a light position detecting means, an image pickup element, and a second optical system for forming an image of an object on the moving stage on a light receiving surface of the image pickup element; The control / processing means moves the moving stage so that the image formed on the light receiving surface of the image sensor is focused at each of n points (n ≧ 3) on the surface of the object. Then, the position coordinate of the moving stage when focused is obtained, and the n points are obtained. Surface S to point of the position coordinates is present substantially
Based on the output of the light position detector when the light position detector detects a light spot formed on the object by the light projecting device while performing the scanning by the light scanning device. The height H of the light spot is detected, the height H is made to correspond to the position of the moving stage at the time of the output, and the height H is converted to the height from the surface S. Characteristic height measuring device. 7. The reference height determining means includes a light source, a collimator for collimating the light emitted from the light source, and one of the light passing through the collimator, the light being disposed in the optical path of the first optical system. 7. The height measuring device according to claim 6, further comprising: a half mirror that reflects a portion, wherein the light reflected by the half mirror is focused and irradiated onto the object. 8. A design pattern storage means in which design pattern data of the object is stored, an actual pattern storage means in which an image captured by the image sensor is stored, a parameter storage means, a display device and a position designation. A console having means, and the control / processing means causes the display device to display the design pattern based on the contents of the first storage means, and the design pattern displayed on the display device. The designated position by the position designating means is stored in the parameter storing means as the position of the n point, and after the focusing is performed, the actual pattern stored in the actual pattern storing means and the design pattern storing means are stored. Pattern matching with the stored design pattern is performed, and the designated position on the design pattern is the position on the actual pattern based on the positional deviation of both patterns. Driving the movable stage to match the height measuring apparatus according to claim 6 or 7, wherein the. 9. The moving stage is an XYZ stage, and a direction in which the moving stage is moved so that an image formed on a light receiving surface of the image sensor is focused is a Z direction. The processing means converts the surface S into the expression aX + bY + cH.
= D, where a to d are constants, and the height of the light spot from the surface S is determined. The height according to any one of claims 6 to 8, Measuring device. 10. A moving stage on which an object is mounted and which can be moved three-dimensionally, a projecting means for converging and irradiating the object with light source light from an oblique direction, and a light converging and irradiating on the object. An optical scanning means for scanning the object on the object, an optical position detector, and a first optical system for forming an image of reflected light from the object on the light receiving surface of the optical position detector. A reference height determining means including a light position detecting means, an image pickup element, and a second optical system for forming an image of an object on the moving stage on a light receiving surface of the image pickup element; The control / processing means moves the moving stage so that an image of the object formed on the light receiving surface of the image pickup element is focused, and in the focused state, the object is projected by the light projecting means. The light position detector when a light spot formed on an object is detected by the light position detector The height H of the light spot is detected as a reference height H0 on the basis of the output of the light spot to correlate the relationship between the focus position of the object and the output of the light position detector. Measuring device.