JP2011095512A - Confocal microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a confocal microscope for acquiring height information (e.g., ruggedness value) about a surface of a sample object to be observed, which is configured more easily and more inexpensively than in a conventional manner. <P>SOLUTION: The confocal microscope is configured to: use a pinhole disk having pinholes, and formed by laminating at least three kinds of thin-film wavelength filters having different wavelength shielding characteristics; previously acquire a variation of surface image light intensity at each wavelength caused by a deviation between the focal plane and the object surface at each wavelength, after converting the variation to a height variation of the surface; besides, perform the detection intensity normalization processing, etc.; and then, measure the ruggedness on the surface of the object to be measured. Accordingly, the mechanical movement of the lens is unnecessary, then, the measuring speed and the simplification of the measuring system can be achieved, further, it is unnecessary to use an expensive optical element or the like. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a confocal microscope, and more particularly to a confocal microscope suitable for measuring a height distribution of a sample surface to be observed.

  Conventionally, a pinhole substrate in which a plurality of pinholes are formed, for example, a disk-shaped pinhole forming substrate called a “Nipkou Disc” spirally arranged at an interval 10 times the pinhole diameter is rotated. A confocal microscope that forms an image of light passing through a pinhole is known. Confocal microscopes have a confocal effect because pinholes are arranged at conjugate positions with the sample surface, and are characterized by high resolution and high-contrast images compared to other types of optical microscopes. is doing. In particular, the resolution in the optical axis direction is high, and information on the height direction of the sample surface can be obtained with high accuracy. In addition, since scanning with a pinhole on the sample surface is performed at a high speed rotation of a disk having a plurality of pinholes in the microscope field of view, it can be compared with other types of optical microscopes by either the human eye or a light detection element. Similarly, the sample surface can be observed in real time.

  When observing the surface of a semiconductor element or the like, the surface usually has a three-dimensional structure, that is, a stepped structure such as an unevenness, so it is necessary to simultaneously observe information in the step at a deep focal depth. . However, in the conventional confocal microscope, since the depth of focus in the depth direction is shallow, it is difficult to observe the three-dimensional structure of such an object. As a method for solving the disadvantage, by changing the mutual distance between the objective lens and the sample, for example, by moving the sample stage on which the sample is mounted in the optical axis direction, and obtaining images at a plurality of focal lengths, Information on the optical axis direction of the sample (that is, the vertical depth direction) is obtained.

  The depth of the material surface by so-called vertical scanning, in which the focal length is changed while mechanically moving the position of the (object) lens or sample stage in the direction of the optical axis in order to obtain a focused image at each position. The method for obtaining the direction information requires a mechanical driving means or a driving means for an image observation prism, for example, an image acquisition system that moves in synchronization therewith. A confocal microscope having such a configuration is not easy in synchronization and various adjustments between driving means, in addition to increasing the number of components and complicating the system.

  As a method of avoiding vertical scanning by a direct mechanical method, for example, a pinhole disk in which pinholes (openings) having different sizes are formed at different positions in the optical axis direction, specifically, for example, transparent There has been proposed a method using a pinhole disk in which a plurality of single-layer disks in which a large number of pinholes are formed on the disk are stacked. In this way, images with different focal positions are acquired. In this case, in order to separate and store images with different focal points, images are captured in synchronization with the rotation of the pinhole disk, and frames corresponding to the number of stacked disks are captured. Perform arithmetic processing between images.

  As another avoidance method, for example, a method has been proposed in which light wavelengths of illumination light are multiplexed and image information is obtained for each wavelength (color). In this case, an optical element that generates chromatic aberration on the optical axis is arranged between the objective lens and the pinhole disk, and reflected light from different sample positions is pinholed according to each of the multiple light wavelengths generated by the chromatic aberration. By forming an image on the top, an image of the sample surface in the depth direction can be simultaneously color-coded and measured.

JP-A No. 200-310735 Japanese Patent Laid-Open No. 08-033948 JP-A-10-221607

  However, in the case of using a method in which a plurality of single-layer pinhole discs having different sizes of pinholes (openings) formed at different positions in the optical axis direction are used, It is necessary to stack the positions and the mutual positional relationship of each single-layer disc strictly. That is, in this method, there is a problem whether or not pinhole disks having a stacked configuration as a point can be manufactured with high accuracy, and this is not always easy.

  On the other hand, in the method of multiplexing the light wavelengths of illumination light, it is important to introduce a chromatic aberration generating element having stable characteristics. However, the chromatic aberration generating element as required is considerably expensive, and a confocal microscope There is a problem that the manufacturing cost of the system becomes high.

  Therefore, the problem of the present invention is that it does not use vertical scanning with mechanical movement of a lens, a sample stage, etc., as compared with a conventional confocal microscope, and is cheaper and easier than a conventional proposed method. An object of the present invention is to provide a confocal microscope capable of acquiring information in the optical axis direction of the surface, that is, measuring in the depth direction of the sample surface.

The confocal microscope of the present invention is
A light source for illuminating the sample;
A pinhole substrate having a plurality of pinholes disposed between the light source and the sample;
A rotating means for rotating the pinhole substrate;
An objective lens is provided between the pinhole substrate and the sample,
The pinhole substrate is rotated to perform optical scanning, a surface image of the sample is generated on the pinhole substrate, and the surface image transmitted through the pinhole is projected onto a first detector. And
The pinhole substrate has at least three thin film laminated portions having different optical wavelength filter characteristics.

  With the confocal microscope of the present invention, it is possible to measure the depth direction of the sample surface more quickly, inexpensively and easily without using vertical scanning with mechanical movement of the lens, sample stage, etc. Become.

Diagram explaining basic configuration of confocal microscope The figure explaining the relationship between the focal plane, relative position, and surface reflected light intensity The figure explaining the lamination | stacking pinhole disk of this invention The figure explaining the Example of the apparatus of this invention Diagram explaining characteristics of light source Diagram explaining characteristics of wavelength filter

Embodiments of the present invention will be described below with reference to the accompanying drawings.
(Basic configuration and examination of confocal microscope)
1 and 2 are diagrams for studying the configuration of the confocal microscope and the measurement method of the device of the present invention using the confocal microscope.

  FIG. 1 is a diagram for explaining a basic configuration of a related-art confocal microscope. The light emitted from the light source 1 is converted into a parallel light flux by the collimator lens 2, reflected by the half mirror 3, and illuminates the pinhole disk 4. Only the light that has passed through the pinhole 5 formed in the pinhole disk 4 is converted into a parallel light beam by the lens (1) 6, and then passes through the objective lens 7 and the focal plane near the surface of the object 8 such as the sample to be measured. 9 is imaged and reflected by the surface of the object 8. The reflected light passes through the pinhole 5 through the objective lens 7 and the lens (1) 6. Of these, the light transmitted through the half mirror 3 is collected by the lens (2) 10 and forms an image on the image sensor 11.

  At this time, when the positions of the focal plane 9 and the surface of the object 8 in the vertical direction coincide with each other, the reflected light from the surface of the object 8 forms an image on the pinhole disk 4, so that most of the light amount is pinhole 5. Pass through. Accordingly, at this time, the light intensity on the image sensor 11 is maximized. Conversely, if the surface of the object 8 is deviated from the focal plane 9, the reflected light from the surface of the object 8 has an image on the pinhole disk 4 larger than the pinhole 5. The light intensity on the image sensor 10 becomes small.

  The pinhole disk 4 and the pinholes 5 formed therein are, for example, well-known NIPCO's in which the positions of the pinholes 5 are arranged at equal central angles and the distance from the center of the disk is formed on a spiral locus. A Nipkow disk or the like can be used.

  When such a pinhole disk 4 is rotated, the position of the illumination light in the focal plane can be changed in order. When an element capable of detecting a two-dimensional light intensity such as a two-dimensional CCD is used as the imaging element 11, a portion where the vertical position of the surface of the object 8 (surface irregularity of the object 8) matches the focal plane 9 is bright. The object 8 can be picked up as a dark image at a location shifted without matching.

  In such a confocal microscope configuration, for example, the focal plane 9 is continuously moved in the vertical direction by continuously changing the vertical distance L between the objective lens 7 and the object 8, that is, vertical scanning of the focal plane. Thus, by receiving a plurality of images (reflected light intensity) on each focal plane 9, it is possible to measure the unevenness of the surface of the object 8 from the change in the light intensity. The means for actually realizing this is, for example, simply by moving the objective lens 7 continuously mechanically by a certain amount in the vertical direction, and continuously reflecting the reflected light from a fixed point on the object surface. The image at the position is acquired, the brightness at the same position in the image is compared between the acquired images, and information on the depth direction of the surface of the object 8 is obtained from the position of the objective lens 7 when the maximum amount of light is obtained. Can do.

  Furthermore, in order to obtain the maximum light amount, it is not always necessary to continuously perform vertical scanning by searching for a lens position where the object surface and the focal plane coincide with each other. If a correlation with the degree of decrease in the amount of light is obtained, the deviation of the object surface from the reference plane can be presumed and information on the depth direction of the object surface can be obtained.

  In addition, the lens moving operation described above is performed by changing the relative position between the focal plane determined by the arrangement of the optical system and the object surface, and examining the brightness of the image light at each relative position reaching the image sensor. The distance relation between each point on the object surface corresponding to each is examined. Accordingly, it goes without saying that the same effect can be obtained even if the position of the pinhole disk is changed in the vertical direction.

  In the optical system having the configuration shown in FIG. 1, when obtaining the shape information of the object surface by performing such vertical scanning, the position of the reference focal plane (standard focal plane) matches the position of the object surface. Sometimes the light intensity is maximum, but the relative intensity of the distance from the focal plane to the object surface reduces the observed light intensity regardless of whether the distance is longer or shorter. . In other words, whether the change in light intensity is due to the distance relationship between the measurement focal plane and the object surface at that time has become shorter or longer, or conversely, whether the object surface has become higher or lower on the optical axis. Is determined by at least three vertical movements of the focal point (that is, the relative heights of the three focal planes = the surface of the measurement object and the three focal positions and the distances). It is necessary to know the changing tendency of intensity.

When the object position is fixed and the focal plane is changed using the graphs of FIGS. 2A, 2B, and 2C, the surface of the object is moved by three vertical movements (= three fixed focal planes). A method for obtaining the positional relationship (whether it has become lower or higher) will be described. The graph of FIG. 2 is plotted according to the brightness of the corresponding point in the image when the focal plane of the optical system of FIG. 1 is changed, and the horizontal axis is the relative position of the focal plane (long and short focal length), The vertical axis represents surface brightness (both are arbitrary units). Here, the light intensity at the standard focal plane height O serving as a reference, the light intensity at the focal plane position A lower than the standard focal plane, and the light intensity at the focal plane position B higher than the standard focal plane are compared. When the surface brightness at each of the three focal plane positions A, O, and B is compared, the following relationship is obtained.
(I) When the object surface is at a position lower than the intermediate standard focal plane O FIG. 2 (a)
The brightness is maximum at a low focal plane position A and minimum at a high focal plane position B.
(Ii) When the object surface is at a position higher than the intermediate standard focal plane O FIG. 2 (b)
The brightness is minimum at a low focal plane position A and maximum at a high focal plane position B.
(Iii) When the object surface is in the middle standard focal plane O or in the vicinity thereof FIG. 2 (c)
The brightness is the maximum at the standard focal plane height O, the lower focal plane position A and the slightly higher focal plane position B are both smaller, and the height of the object surface is closer to A or B closer to the brightness. Become big.

  As described above, the surface height of the object surface to be observed and the standard focal plane are calculated based on the relationship between the brightness levels of the reflections from the object surfaces in the standard focal plane O and the focal planes A and B in total of three focal planes. The height relationship with O can be known, and the distance between the three focal planes and the change in brightness of the object surface with respect to the focal plane height, that is, the intermediate between the three focal planes. If the relationship between the height of the object and the brightness is examined in advance, the relative height at each point on the object surface can be accurately obtained from the ratio of the focal plane height and the brightness at the three points.

  The above is the basic measurement method concept by the apparatus of the present invention, which basically uses a confocal microscope and performs three-point vertical scanning (= three fixed focal planes) to obtain the shape (unevenness) of the object surface. .

When the above method is actually carried out, in the confocal microscope of the present invention, a laminated pinhole disk having a three-layer structure is applied as a means for obtaining three focal planes of the respective focal positions A, O, and B.
(Example)
FIG. 3 is a schematic cross-sectional view of an example of a laminated pinhole disk used in the apparatus of the present invention. This laminated pinhole disk 12 is a thin film wavelength filter 14 (14-1, 14) having a wavelength filter effect for blocking only a specific light wavelength on a transparent substrate 13 (13-1, 13-2, 13-3) such as glass. -2, 14-3) are formed as shown in the figure, and each thin film wavelength filter 14 is provided with fine pinholes 15 (15-1, 15-2, 15-3). The filter characteristics of the respective thin film wavelength filters 14 are different from each other, and the pinhole 15 is formed at a position such as a Nipkow disk.

  As shown in the figure, the laminated pinhole disk 12 has, for example, a three-layer thin film wavelength filter disk structure, and the thin film wavelength filters 14 (14-1, 14-2, 14-3) are respectively R, G, B ( A reflective wavelength filter that selectively and non-transmits only the wavelengths of red, green, and blue (in contrast, non-transmitted wavelength light of each film passes only from pinholes formed in each film). It is assumed that the laminated pinhole disk 12 on which the three layers of films are laminated is arranged on the pinhole disk 4 of FIG. At this time, the thin film wavelength filters 14 (14-1, 14-2, 14-3) are formed at intervals of the thickness D2 of the transparent substrate 13-2 and the thickness D3 of the transparent substrate 13-3. Thus, the three-layer pinhole disk film structure 16 that can be considered to form a focal plane equivalent to the three focal plane positions A, O, and B described with reference to FIG. 2 is formed. If so, the output image of R, G, B in the color sensor is the focal plane of the lens system configured at each R, G, B wavelength, that is, the object surface reflecting the respective positions of A, O, B Therefore, information on the height of the object surface can be obtained from the amount of change in the amount of light.

  FIG. 4 shows a confocal microscope of the present invention having such a configuration. The light source 18 of the confocal microscope 17 is preferably a white light source having a separable color (wavelength) component. Furthermore, considering the ease of image component separation processing in the subsequent stage, for example, R, G, and B wavelengths separated as shown schematically in FIG. A white light source obtained by combining B3 color LED light sources is more suitable. In FIG. 5, the horizontal axis represents the wavelength, and the vertical axis represents the emission intensity (arbitrary unit) of the incandescent light source at each wavelength.

  The light emitted from the light source 18 is converted into a parallel light beam by the collimator lens 19, reflected by the half mirror (1) 20, and irradiated on the laminated pinhole disk 21. The laminated pinhole disk 21 has the same configuration as that described with reference to FIG. 3. For example, each thin-film wavelength filter having a three-layer structure has only R, G, and B wavelength components of the light source 18 that is a white light source. The reflection type wavelength filter is made to transmit, and acts so that each wavelength light passes only from the pinhole formed in each reflection type wavelength filter. In FIG. 6, the schematic diagram of the transmission characteristic of each thin film wavelength filter (R filter, G filter, B filter) is shown. In FIG. 6, the horizontal axis represents the wavelength, and the vertical axis represents the transmittance (arbitrary unit) of each filter. Such a filter can be formed by forming a dielectric multilayer film on a transparent glass substrate by a manufacturing method similar to a commercially available dichroic mirror. Referring to FIG. 3, a single-layer pinhole disk is formed so as to have pinholes 15 in each wavelength-corresponding thin film wavelength filter 14 on each transparent substrate 13, and these are laminated. The pinhole 15 can be easily manufactured by using ordinary photolithography and etching techniques. In each transparent substrate 13, the transparent substrate 13-1 (thickness D 1) has only enough to withstand deformation due to rotation of the laminated pinhole disk 12 itself, for example, a thickness of about several mm. The transparent substrates 13-2 (thickness D2) and 13-3 (thickness D3) are gaps between the films, and the thickness is, for example, about 10 to 15 μm. The diameter of the pinhole 15 is assumed to be about 1 μm, for example.

  Thus, since the pinhole 22 of the thin film wavelength filter of the laminated pinhole disk 21 in FIG. 4 transmits only the corresponding wavelength component (RGB wavelength) in the light source 18, each wavelength (RGB wavelength) has a different position in the focal direction ( In order to form a point light source at each RGB wavelength position), the light beams that have passed through the pinhole 22 and expanded by the lens (1) 23 are transmitted through the half mirror (2) 24, passed through the objective lens 25, and have different heights. The image is formed on the focal plane 26 (RGB focal planes). The light reflected by the surface of the object 27 to be observed is reflected by the half mirror (2) 24 and passes through the lens (3) 24 to form an image on the color image sensor 29, and the half mirror (2 ) 24, and through the lens (1) 23, it is separated from the light directed to the laminated pinhole disk 21. The light incident on the color image sensor (2) 29 is an image for each wavelength component; R2, G2, B2 (in this case, the light intensity output not affected by the thin film wavelength filter of the laminated pinhole disk 21. Non-color filter output (NCF-output).

  Each wavelength component of the light directed to the laminated pinhole disk 21 is collected by the lens (1) 23 and forms an image near the laminated pinhole disk 21, but on a filter (thin film wavelength filter) corresponding to each wavelength. Only the light in the case of forming an image can pass through the pinhole 22 of the thin film wavelength filter with all the light amounts. When imaging is not realized, only a part of the light quantity is transmitted. The light that has passed through the pinhole 22 passes through the half mirror (1) 20 and is imaged on the color image sensor (1) 31 by the lens (2) 30. The light incident on the color imaging device (1) 31 is an image for each wavelength component; R1, G1, B1 (in this case, a light intensity output affected by the thin film wavelength filter of the laminated pinhole disk 21; color Filter output; CF-output). As the color image sensor (1) 31 and the color image sensor (2) 29, a three-element CCD camera may be used.

  According to the above description, in the case of an object that does not have much wavelength dependency of reflected light intensity in visible light (appears white, gray, or black), the images of B, G, and R are described with reference to FIG. Further, it can be seen that the (unevenness) shape of the object surface can be obtained by considering the images at the focal planes of A, O, and B.

When the reflected light of the object surface to be measured has a wavelength characteristic, that is, when the object surface is colored, R, G, B, etc., are factors other than the relationship between the focal plane and the height of the object surface depending on the surface color. The reflected light intensity of each image may be determined. In this case, the color of the object surface can be adjusted by using an image obtained by focusing the light reflected by the half mirror (2) 24 on the color image pickup device (2) 29 by the lens (3) 28 as a calibration output. The height information of the reflected object surface can be acquired. Since the reflected light focused on the color imaging device (2) 29 does not pass through the laminated pinhole disk 21, it can be considered that the intensities of R, G, and B are determined only by the wavelength characteristics of the surface of the object 27. . Therefore, using the intensity information of the corresponding position of the image of the color image sensor (2) 29, the color information of the object surface is excluded from the intensity of the R, G, B image of the color image sensor (1) 31, and the comparison is performed. Convert to a possible image. That is,
The intensity of each pixel of the color image sensor (1) 31 is set as follows.

R1 (x, y), G1 (x, y), B1 (x, y)
The intensity of each pixel of the color image sensor (2) 29 is set as follows.

R2 (x, y), G2 (x, y), B2 (x, y)
The correction strengths Rh, Bh, and Gh for each color excluding color information on the object surface are as follows.

Rh (x, y) = R1 (x, y) / R2 (x, y)
Gh (x, y) = G1 (x, y) / G2 (x, y)
Bh (x, y) = B1 (x, y) / B2 (x, y)
Each image is taken into a personal computer, for example, and the above calculation is performed, and the values of Rh, Bh, and Gh are compared to obtain height information on the object surface.

  Further, for example, the height Z of the object surface can be obtained from Rh, Bh, and Gh using a height calculation reference table as shown in Table 1.

  The height calculation reference table in Table 1 may be created by using a flat plate with high flatness in advance and calculating using an image captured while changing the height with the optical system of FIG. In this table, normalization is performed by the following calculation so that the sum of the values of R, G, and B is always constant (for example, 100).

Rp (x, y) = Rh (x, y) / (Rh (x, y) + Gh (x, y) + Bh (x, y)) * 100
Gp (x, y) = Gh (x, y) / (Rh (x, y) + Gh (x, y) + Bh (x, y)) * 100
Bp (x, y) = Bh (x, y) / (Rh (x, y) + Gh (x, y) + Bh (x, y)) * 100
In the above embodiment, from the viewpoint of automatic measurement of unevenness on the surface of an object, a configuration and a specific method for calculating the height by taking R, G, and B image intensity measurement values obtained by the image sensor into a personal computer or the like and performing calculation processing However, since the height information can be obtained as the color information of the image in the apparatus of the present invention, it is needless to say that the shape of the object can be observed not by automatic processing but also by visual observation. No.

  In the embodiment of the confocal microscope of the present invention described above, the configuration of the thin film wavelength filter is exclusively based on the three wavelength components of R, G, and B, and accordingly, based on the light source used and the three focal planes. The correction method to be performed and the height calculation reference table associated therewith are described, and it has been described that the height measurement of the object surface can be performed by this apparatus. This eliminates the need for mechanical movement of the lens and the like, thereby improving the measurement speed and simplifying the measurement system and making it unnecessary to use expensive optical elements.

  As is clear from the purpose of the description so far, in the present confocal microscope, it is not necessary to use the three wavelength components of R, G, and B. For example, at least three or more types of arbitrary wavelengths A laminated pinhole disk having a thin film wavelength filter similar to that described in the embodiment is used at different wavelengths, and a focal plane corresponding to each wavelength using a light source having these wavelengths. It is clear that it is possible to obtain information about the height of the object surface by grasping the calibration table in advance as a function of the reflected light intensity and the deviation (distance) of the object surface, and it is clear that it is cheap and easy to measure. In addition to the above features, depending on the wavelength conditions and the number of wavelengths used, it is possible to further improve the measurement accuracy of the object surface height and further expand the height measurement range.

The following additional notes are disclosed regarding the embodiments including the above examples.
(Appendix 1)
A light source for illuminating the sample;
A pinhole substrate having a plurality of pinholes disposed between the light source and the sample;
A rotating means for rotating the pinhole substrate;
An objective lens is provided between the pinhole substrate and the sample,
The pinhole substrate is rotated to perform optical scanning, a surface image of the sample is generated on the pinhole substrate, and the surface image transmitted through the pinhole is projected onto a first detector. And
2. The confocal microscope according to claim 1, wherein the pinhole substrate has a plurality of thin film laminated portions having at least three layers and different optical wavelength filter characteristics.
(Appendix 2)
The confocal microscope according to appendix 1, wherein the plurality of thin film laminated portions are separated by a transparent layer.
(Appendix 3)
The light source includes wavelength light separable by the optical wavelength filter characteristic, and the first detector is capable of detecting the surface image by the separable wavelength light. The confocal microscope described.
(Appendix 4)
The confocal microscope according to any one of appendices 1 to 3, further comprising means for calculating a surface height of the sample from a light intensity of the surface image detected by the first detector.
(Appendix 5)
Furthermore, a half mirror is provided between the pinhole substrate and the objective lens, and there is provided a second detector on which the surface image of the sample is projected. Confocal microscope.
(Appendix 6)
The confocal microscope according to claim 5, further comprising means for calculating a surface height of the sample from a light intensity of the surface image detected by the first detector and the second detector.
(Appendix 7)
7. The confocal microscope according to any one of appendices 3 to 6, wherein the separable wavelength light is light in a wavelength band of R (red), G (green), and B (blue).
(Appendix 8)
The confocal microscope according to appendix 7, wherein the first detector and the second detector are color imaging elements.

1, 18 Light source 2, 19 Collimator lens 3 Half mirror 4 Pinhole disk 5, 15, 22 Pinhole 6, 23 Lens (1)
7, 25 Objective lens 8, 27 Object 9, 26 Focal plane 10 Lens (2)
DESCRIPTION OF SYMBOLS 11 Image pick-up element 12, 21 Laminated pinhole disk 13 Transparent substrate 14 Thin film wavelength filter 16 Three-layer pinhole disk film structure 17 Confocal microscope of the present invention 20 Half mirror (1)
24 half mirror (2)
28 Lens (3)
29 Color image sensor (2)
30 lenses (2)
31 Color image sensor (1)

Claims (5)

A light source for illuminating the sample;
A pinhole substrate having a plurality of pinholes disposed between the light source and the sample;
A rotating means for rotating the pinhole substrate;
An objective lens is provided between the pinhole substrate and the sample,
The pinhole substrate is rotated to perform optical scanning, a surface image of the sample is generated on the pinhole substrate, and the surface image transmitted through the pinhole is projected onto a first detector. And
2. The confocal microscope according to claim 1, wherein the pinhole substrate has a plurality of thin film laminated portions having at least three layers and different optical wavelength filter characteristics.   The said light source contains the wavelength light separable by the said optical wavelength filter characteristic, and the said 1st detector can detect the said surface image by the said separable wavelength light. Confocal microscope.   The confocal microscope according to claim 1, further comprising means for calculating a surface height of the sample from a light intensity of the surface image detected by the first detector.   3. The confocal microscope according to claim 1, further comprising a second detector on which a half mirror is provided between the pinhole substrate and the objective lens and onto which the surface image of the sample is projected. . 5. The confocal microscope according to claim 4, further comprising means for calculating a surface height of the sample from light intensity of the surface image detected by the first detector and the second detector.