JP6715872B2 - Substrate shape measuring device - Google Patents

Description

The present invention relates to an apparatus for measuring the deformation of a large substrate such as a wafer used in the semiconductor field, especially the deformation when heated or cooled.

When three-dimensional stacking by TSV (Through-Silicon Via) is performed by Wafer On Wafer, the warp (deformation from the plane) of the whole wafer becomes a big problem. In particular, since heating is performed in a reflow furnace for solder connection, it is more important to know the deformation behavior due to heat, and realization of a measuring device is an urgent task.

The warp of a flat substrate used in semiconductor products such as wafers is a three-dimensional deformation, and so-called three-dimensional measurement is necessary. There are many three-dimensional measurement methods, but high speed is also required because it is necessary to measure a large substrate, and the three-dimensional measurement method is limited to the non-contact measurement method.

The methods applied to commercially available devices as methods suitable for measuring the deformation of a plane are roughly divided into (1) a method of scanning a point measuring instrument in XY (2) an interferometry method (3) a moire measurement method. There are three.

The method of scanning the point measuring instrument in XY is to mount an optical or capacitance type displacement meter, which is a point measuring instrument, or a goniometer that measures the surface inclination at each point of the object on the XY stage. This is a method of measuring (deformation measuring) the three-dimensional shape of the entire surface of the target substrate by scanning. No matter how large the object is, the size of the point measuring device itself does not need to be changed, so that there is an advantage that it can be manufactured small as a large substrate measuring device. On the other hand, since it requires two-dimensional scanning, it has a drawback that it takes much longer than other methods.

Considering to analyze the deformation behavior due to heat during reflow, it is necessary to measure deformation at various temperatures in the temperature change process (temperature profile) during reflow, but if one deformation measurement takes time. This method cannot be adopted because the temperature profile at the time of reflow cannot be maintained (it becomes a different temperature profile).

The interferometric method is widely used as a method for measuring the warp of a wafer with high accuracy and high speed. In the interferometric method, a Fizeau interferometer using a lens or a reference surface having a size larger than a plane to be measured or an oblique incidence interferometer using a large Abramson prism is used. However, since it is a method of measuring the deformation of the wavefront when the wavefront of light (plane wave) is reflected by the object, the surface of the object is a smooth surface that can maintain the wavefront of light and reflect it ( It needs to be a mirror surface), and lacks versatility. In wafer measurement, bare wafers can be measured, but they are not suitable for patterned wafers or wafer backside measurement.

In the moire method, a grating is arranged close to the substrate to be measured, imaging is performed from above and illumination is performed from diagonally above, and the shadow of the grating projected onto the object to be measured and geometric interference fringes generated by the grating. This is a method of analyzing (moire fringes) and measuring the deformation of the measurement target substrate. Usually, it is realized by using a general imaging lens of the central projection method, so it has the flexibility to change the field of view (measurement range in the XY direction) according to the size of the measurement object, and it is relatively inexpensive. It has the advantages that can be realized.

When using a general imaging lens of the central projection method, the direction of the light ray at each point in the field of view will differ, so if the surface of the measurement object is not a diffusing surface (usually not a diffusing surface) You can't get streaks. Conventionally, as a method for solving this problem, there is a method for ensuring versatility by coating a measurement object and forcibly making it a diffusion surface.

This method is widely used as a measurement device for thermal deformation, but it also requires painting instead of nondestructive inspection, and heating from the grid direction is not possible because the grid is close to the measurement object. There are many problems such as uneven temperature on the object to be measured and the grid is easily soiled.

Matsuoka et al., “Wafer Shape and Flatness Measuring Device”, Kobe Steel Technical Report, p.7, Vol.59, No.2 (2009) Akiyama et al., "Large-Diameter Wafer Flatness Measurement Technology", Japan Society for Precision Engineering, 768 pages, Vol.73, No.7 (2007) Wang et al., ``On-Line Measurement of Thermally Induced Warpage of BGAs with High Sensitivity Shadow Moire'', International Journal of Microcircuits and Electronic Packaging, page 191, Vol.21, No.2 (1998).

As described above, each of the conventional techniques has a fatal problem that it takes a long measuring time, a rough surface cannot be measured, and painting is required.

An object of the present invention is to provide a substrate shape measuring device that does not have these problems. That is, a large-sized substrate including a wafer has a measurement speed that does not affect the reflow temperature profile, and can measure a substrate, whether rough or mirror, without painting it. Is provided.

In order to solve the above problems, a substrate shape measuring apparatus according to an embodiment of the present invention is a specular reflection light receiving arrangement optical system in which two bilateral telecentric lenses are arranged at a symmetric angle with respect to a substrate normal line, and the bilateral telecentric optical system. A grating and an illumination unit for projecting the stripe pattern on one of the lenses through the substrate, a camera for receiving the image of the stripe pattern of the substrate through the other side telecentric lens on the other side, and analysis and deformation of the image obtained by the camera. And an image analysis device for determining the above, and the lattice and the camera are arranged in a tilted manner in accordance with the plane of the substrate.

Further, the substrate shape measuring apparatus can heat or cool the substrate to be measured to an arbitrary temperature, and has a space in the normal direction of the substrate so as not to obstruct the optical path of the specular reflection light receiving arrangement optical system. A heater having a transparent window made of glass or the like may be provided.

Further, the substrate shape measuring device has at least two transparent plates and a mechanism for flowing a gas between them, and is arranged between the heater and the specular reflection light receiving arrangement optical system, and the specular reflection light receiving arrangement optical system. A heat insulating mechanism may be provided to prevent heat from reaching the heater.

The field of view of the camera and the area of the stripe pattern projected on the measurement target substrate are preferably larger than the measurement target region on the substrate.

With the above configuration, it has a measurement speed that does not affect the reflow temperature profile, and can measure the substrate shape without painting, whether it is a rough surface or a mirror surface. The device can be realized.

The figure which showed the Example of this invention. The figure which showed an example of the heater of this invention. The figure which showed an example of the heat insulation mechanism of this invention.

Hereinafter, the best mode for carrying out the present invention will be described.

First, an example of an embodiment embodying the present invention will be described with reference to FIGS.

A substrate shape measuring apparatus according to an embodiment of the present invention, a three-dimensional measuring device 100 for measuring the deformation of the substrate, a heater 200 for heating the substrate, the heat from the heater 200 reaches the three-dimensional measuring device 100. It is composed of a heat insulating mechanism 300 for preventing the above. Each will be described below.

The three-dimensional measuring instrument 100 includes a bilateral telecentric imaging lens 102 for obtaining an image of a substrate 101 to be measured, a camera 103 for converting an image obtained by the imaging lens 102 into an electric signal, and an image from the camera 103 is stored. Then, the image analysis device 104 that digitally analyzes the deformation of the substrate 101, the both-side telecentric projection lens 105 that projects the stripe pattern on the substrate 101, the grating 106 that is the original plate of the stripe pattern, and the stripe pattern A phase shift mechanism 107 for changing the phase of the beam and an illumination unit 108 for illuminating the grating 106.

Here, the projection lens 105 and the imaging lens 102 are arranged angularly symmetrical with respect to the normal line of the substrate 101. This means an optical arrangement in which the illumination light is reflected by the substrate 101 based on Snell's law, that is, so-called regular reflection light is received.

Both the projection lens 105 and the imaging lens 102 are telecentric lenses. Therefore, the principal ray of both the light ray projected on the substrate 101 and the light ray received by the imaging lens 102 is parallel to the optical axis over the entire visual field. Therefore, the imaging lens 102 can receive specularly reflected light over the entire field of view. Therefore, even if the substrate 101 is a mirror surface, it is possible to receive light uniformly over the entire visual field without applying special coating. Of course, even if the substrate 101 is a diffusing surface, it can receive light uniformly over the entire field of view.

On the other hand, the moiré method of the related art is a general center projection type lens in which neither the projection lens nor the imaging lens is telecentric, and is not arranged symmetrically with respect to the normal line of the substrate 101 in the first place. That is, since it is not the regular reflection light receiving arrangement, the regular reflection light cannot be received. Even if the regular reflection light receiving arrangement is adopted, in the central projection lens, since the angle of the light beam is not uniform and differs depending on the position where the light beam passes through the lens, it is not possible to receive the regular reflection light over the entire field of view. Can not.

Therefore, according to the conventional moire method, if the substrate 101 is not a perfect diffusion surface, uniform light reception cannot be performed in the entire field of view. This is the reason why coating is required to forcibly make the substrate 101 a completely diffusing surface. In the present invention, both specular reflection light and diffused light can be received, and the condition of the light rays is uniform over the entire field of view, so there is no need for coating.

In the case of such an optical system having the regular reflection light receiving arrangement, as can be seen from FIG. 1, the distance from the imaging lens 102 to the substrate 101 is not uniform in the visual field. The same applies to the projection lens 105. Since it is a telecentric lens, the imaging magnification does not change even if the distance from the lens to the object changes. That is, the image is not distorted. However, if the distance changes, the image forming position (focus position) also changes.

As a measure against the change of the image formation position, the image plane of the camera 103 (light receiving element arrangement surface) and the grating 106 are tilted. That is, the lens is arranged to be inclined with respect to the optical axis. By arranging the image plane of the camera 103 so as to be tilted, the camera 103 can obtain an image in which the substrate 101 is completely focused within the field of view. The same applies to the striped pattern.

When the image plane of the camera 103 or the grating 106 is tilted with respect to the optical axis of the lens, and if the imaging lens 102 or the projection lens 105 is telecentric only on the object side, the image forming magnification is not uniform. A distorted image will be obtained. Therefore, it is essential for the imaging lens 102 and the projection lens 105 that both sides are telecentric.

In the double-sided telecentric lens, the tilt angle θ of the object plane (the angle between the surface orthogonal to the optical axis and the object plane, the angle between the normal line of the substrate and the optical axis (angle of incidence/reflection)) and the tilt θ′ of the image plane Has a simple relationship such as Equation 1 where M is the magnification of the lens. The image plane of the camera 103 and the tilt of the grating 106 may be determined according to this equation.

[Equation 1]
tan θ'= M・tan θ

Here, an example in which the regular reflection light receiving arrangement is arranged symmetrically with respect to the normal line of the substrate 101 will be described, but this does not mean a strict angle. Since both the projection lens 105 and the imaging lens 102 have a non-zero NA (numerical aperture), specular reflection light can be received even if the arrangement is not strictly symmetrical. On the contrary, if the types of the substrate 101 are limited, it may be possible to obtain a better image by slightly arranging the specular reflection component. It is within the scope of the present invention as long as the positional relationship does not deviate significantly from the symmetrical arrangement and the specularly reflected light can be received.

Another important point in the optical system of the present invention is that the field size is larger than the measurement target area on the substrate 101. For example, when the substrate 101 is a 12-inch wafer and it is desired to measure the warp of the entire wafer, the field of view size is such that at least the entire 12-inch wafer is included.

In thermal deformation measurement, it has already been mentioned that it is important to measure the heating temperature profile without disturbing it in order to correctly measure the thermal deformation behavior during reflow. This means that no special time can be set for measurement, and it is necessary to be able to measure in a very short time. It is necessary to measure instantaneously or within a few seconds at most.

In order to achieve this, it is preferable to perform measurement in one visual field rather than dividing the measurement target region into a plurality of regions. Therefore, assuming that the substrate 101 is a 12-inch wafer, for example, a telecentric lens needs a lens having a larger diameter than the field of view, and therefore a large projection lens 105 and an imaging lens 102 having a diameter of more than 12 inches are required. ..

The element size of recent solid-state imaging cameras such as CCD and CMOS is several mm to several tens of mm diagonally. Considering the field of view of 12 inches (300 mm), the magnification is 1/10. Assuming that the angle θ formed by the lens optical axis and the normal to the substrate 101 is 30°, θ in Equation 1 is 30°, and when M=1/10, θ′ is only 3.3°. When the image plane of the camera 103 is largely tilted, the incident angle of light to the pixel is tilted, so that the pixel size is substantially reduced, or the efficiency of light incidence on the pixel is significantly deteriorated. However, if the lens has a large field of view and a high reduction magnification like the substrate shape measuring apparatus according to the present embodiment (and if it is image-side telecentric), such a problem can be avoided.

Here, the measurement is limited to only one visual field, but this is not essential to the present invention. For example, for an object that can be measured in two fields of view, it is not impossible to measure within a few seconds even if instantaneous measurement is impossible. The present invention requires a wide field of view, that is, a high reduction magnification, but does not necessarily have to be one field of view.

The image analysis device 104 is composed of, for example, a personal computer or a workstation, and has at least a storage medium for storing an image from the camera 103 and a processor for digitally analyzing the image and measuring the shape of the substrate 101 by calculation. Prepare The measurement is performed by a so-called lattice pattern projection method. When the stripes are projected on the object and observed from a direction different from the projected direction, the stripes are distorted according to the undulations of the object. Since the distortion includes the undulation information of the object, it is possible to obtain the three-dimensional shape information of the object by calculation.

Various methods for calculating three-dimensional shape information from stripe distortion information have been proposed, and an appropriate one may be selected and calculated. References on the method of fringe analysis include Takeda, "Basic theory of sub-fringe interferometry", Optics, page 55, Vol. 13 (1984).

For example, there is a phase shift method as a versatile and highly reliable calculation method. The initial phase of the stripe is obtained for each pixel of the camera 103 by shifting the grating 106 a plurality of times by a fraction of the grating period (that is, by shifting the phase) to obtain an image in which the phase of three or more stripes is shifted. Therefore, the three-dimensional shape information can be obtained from the geometric relationship between the initial phase and the lens arrangement.

Various mechanisms can be considered for the phase shift mechanism 107 that is a mechanism for phase shifting the grating 106. It is common to move the grating directly by a uniaxial moving mechanism (direct acting mechanism), but the grating is configured using a transmissive or reflective liquid crystal display element and is mechanically moved by shifting the display. There is also a method that can realize the phase shift without performing the above. It is also conceivable to use a MEMS display element such as a digital mirror device instead of the liquid crystal element.

When performing stripe pattern projection using a display element, the period of the grating can be changed freely, so by projecting multiple stripe patterns with different periods, the measurement range in the height direction can be greatly expanded. Is also possible.

When a plurality of images whose acquisition timings are different with respect to time are used like the phase shift method, a correct result can be obtained when the measurement target is moving, for example, when the shape of the substrate 101 is rapidly changed due to heat. May not be obtained. For such a case, many methods have been proposed in which measurement can be performed instantaneously, that is, a three-dimensional shape can be calculated from a single striped image. There is a Fourier transform method as a typical method. Examples of the literature of the Fourier transform method include Takeda et al., "Fourier transform profile for the automatic measurement of 3-D object shapes", Appl. Opt., page 3977, Vol. 22, (1983).

According to the Fourier transform method, the initial phase can be obtained from all the pixels from one image similarly to the phase shift method, and the three-dimensional shape can be calculated. Although the actual resolution in the XY directions is inferior to that of the phase shift method, extremely robust and highly accurate measurement is possible. The data acquisition time is instantaneous, which can be said to be suitable for the time analysis of thermal deformation.

The above is the embodiment of the three-dimensional measuring instrument 100 in the present invention. Although only one set of the three-dimensional measuring instrument 100 is used here, for example, by using two sets and arranging each in the X direction and the Y direction, more reliable measurement can be performed. Such a case is also within the scope of the present invention.

It is more preferable for the substrate shape measuring apparatus to further include the heater 200 and the heat insulating mechanism 300 as shown in FIG. 1 in addition to the three-dimensional measuring device 100, because thermal deformation of the substrate can be measured. Therefore, next, the heater 200 will be described. The heater 200 is a device for uniformly heating the substrate 101 to an arbitrary temperature. It comprises a heating furnace 201 and a temperature control device 202 for controlling the heating furnace 201. For example, when the temperature control device 202 and the image analysis device 104 communicate with each other and synchronize with each other, it is possible to realize automatic measurement such that the deformation of the substrate 101 is measured every time the temperature of the substrate 101 changes by 10 degrees. is there.

There are three types of methods for heating the substrate 101, roughly classified according to which of the three states of heat transfer is used. There are three methods: a method of using a hot plate that heats by heat conduction, a method of using heat radiation by an infrared lamp, and a method of convective heat transfer in which air is heated and blown onto the substrate 101.

In the method using heat radiation, when the substrate 101 is a metal such as a wafer, it cannot be directly heated due to metal reflection (indirectly, a black-painted plate is heated by heat radiation, and the plate and the wafer are heated). It can be contacted to conduct heat, which is included in the heat transfer method).

Further, the method using heat conduction has a problem that a temperature difference occurs between a portion in contact with the hot plate when the substrate 101 warps due to heating and a portion apart from the warp, and the temperature difference causes deformation. Conceivable.

Although the present invention does not limit the heating method, it is believed that heating by convective heat transfer is the best. Since the reflow furnace is also heated by convection heat transfer, convection heat transfer is also excellent in terms of better simulation. Here, heating by convection heat transfer will be described as an example with reference to FIG.

The heating furnace 201 has a structure in which a heat insulating material 203 covers a space in which an object to be heated is placed. The upper surface is provided with an opening on the side of the three-dimensional measuring instrument 100 so that the three-dimensional measuring instrument 100 can measure and does not interfere with the optical path of the optical system of the three-dimensional measuring instrument 100. A member that transmits light may be arranged in the opening. Since the three-dimensional measuring instrument 100 measures the substrate 101 using the light transmitted through the light transmitting member, the light transmitting member has a high transmitted wavefront accuracy so that the illumination light and the image forming light wavefront do not have aberrations. Need to be. Further, in order to prevent heat radiation through the light transmitting member as much as possible, a plurality of light transmitting members may be used as a heat insulating measure, and a gas such as air or a vacuum space may be provided inside. FIG. 2 shows an example in which two parallel flat plate type transparent glasses 204 are densely provided in the openings as the light transmitting member so as to be parallel to and separated from each other, and the separated space is air.

The heating furnace 201 takes in factory air, raises the temperature to a temperature controlled by a temperature control device 202 when the air passes through the coil heater 205, and the hot air is sent into the furnace. The hot air flowing in the furnace is discharged from the exhaust port 206 to the outside of the factory through the exhaust duct 207.

The space temperature in the furnace is monitored by the thermometer 208, and by feeding back the temperature information from the thermometer 208 to the temperature control device 202, accurate temperature control in the furnace becomes possible.

Here, an example in which the transparent glass 204 is densely provided in the opening of the upper part (the part on the three-dimensional measuring instrument 100 side) of the heating furnace 201 for heating by convective heat transfer has been described, but the flow of air is controlled. In the case of hot plate heating or infrared lamp heating that does not need to be performed, the transparent glass 204 is not always necessary. It suffices for the aperture to allow the measurement light beam of the three-dimensional measuring instrument 100 to pass through, and for example, the space may be left open without the transparent glass 204.

Next, the heat insulating mechanism 300 will be described. In the heater 200, not only when the transparent glass 204 is not provided on the upper surface, but even when the transparent glass 204 is present, the air around the transparent glass 204 is warmed as the temperature of the transparent glass 204 rises, and rises to form convection. Heat is transferred to the three-dimensional measuring instrument 100. In addition to convection, radiant heat is emitted from the heated substrate 101 or the heated transparent glass 204 and is transferred to the three-dimensional measuring instrument 100.

Since the three-dimensional measuring instrument 100 is composed of a precision optical system, it produces various errors when heated. For example, each of the projection lens 105 and the imaging lens 102 is composed of a large number of single lenses, but when the temperature changes, the distance between the single lenses, the curvature and thickness of the single lenses themselves change due to thermal expansion, and Image performance will change. The camera 103 also has a problem that noise increases due to heat.

Further, since the refractive index of air changes depending on the temperature, if the temperature uniformity of the space is disturbed by the rising convection, the refractive index becomes uneven, so-called fluctuation occurs, and the measurement error increases. In order to deal with these problems, it is preferable to provide the heat insulating mechanism 300. The heat insulating mechanism 300 will be described below mainly with reference to FIG.

Fluctuations due to convection have a greater effect as the distance of the convection space increases. Therefore, it is effective to limit the distance at which convection is possible. Therefore, a barrier 301 that blocks convection is provided at a position as close to the upper surface of the heater 200 as possible. Since it is necessary for the three-dimensional measuring instrument 100 to be able to measure, the portion of the barrier 301 through which the luminous flux of the three-dimensional measuring instrument 100 passes is configured by using a member that transmits one or a plurality of lights. FIG. 3 shows an example in which transparent bodies 302 and 303 such as glass are used as a light transmitting member that constitutes a part of the barrier 301.

Since the barrier 301 is heated by convection, it needs to be insulated so as not to transfer heat to the optical system of the three-dimensional measuring instrument 100. The portions other than the transparent bodies 302 and 303 form the barrier 301 with a material such as copper having good thermal conductivity, and by passing cold water inside the barrier 301, the heat is transferred in the material from the bottom to the top. It is possible to take away the heat and prevent the heat from being transferred to the upper surface of the barrier 301. It is advisable to use the chiller 304 to dissipate the deprived heat and generate cold water again to circulate it.

Since cold water cannot be used in the light transmitting member portion, a plurality of light transmitting members are provided so as to be separated from each other, for example, two upper and lower transparent bodies 302 and 303 as shown in FIGS. 1 and 3. And let air flow in between. Although the lower transparent body 302 is heated and its temperature rises, it is possible to prevent the heat transfer to the upper transparent body 303 by constantly flowing the air at room temperature, and the upper transparent body 303 avoids the temperature rise.

As a measure against heat radiation, it is conceivable to apply a thin film to the transparent body 302 on the heater 200 side so as to reflect the target radiant light, but the peak of the radiant light emitted from an object at about 200 to 300°C. The wavelength is about 5 to 6 μm, and since ordinary glass materials cannot transmit this wavelength, it is considered that no particular measures need to be taken.

According to the three-dimensional measuring device 100 of the substrate shape measuring apparatus according to the above-described embodiment, it is possible to measure the substrate shape at an extremely high speed without coating even if the substrate is a rough surface or a mirror surface. You can Further, when the substrate shape measuring device has the heater 200 and the heat insulating mechanism 300, the target substrate 101 can be further heated according to the reflow temperature profile, and the influence of the heating influences the three-dimensional measuring device 100. It is possible to realize a substrate shape measuring device that can perform thermal deformation measurement at a measurement speed that does not affect the reflow temperature profile and that does not require coating even if the substrate 101 is a rough surface or a mirror surface. ..

It is considered that the present invention has a particularly great demand for a test at the time of developing a substrate or a test at the time of shipping in the semiconductor industry where there are many substrates that require heating in the manufacturing process.

100 three-dimensional measuring instrument 101 substrate 102 imaging lens 103 camera 104 image analysis device 105 projection lens 106 grating 107 phase shift mechanism 108 lighting unit 200 heater 201 heating furnace 202 temperature control device 203 heat insulating material 204 transparent glass 205 coil heater 206 exhaust port 207 Exhaust duct 208 Thermometer 300 Insulation mechanism 301 Barriers 302, 303 Transparent body 304 Chiller

Claims (4)

A device for measuring the shape of large substrates such as wafers,
A specular reflection light receiving arrangement optical system in which two bilateral telecentric lenses having a field of view larger than 150 mm and a reduction magnification of at least 5 times are arranged symmetrically at a first angle with respect to a normal line of the substrate;
A grating and an illumination unit for projecting a fringe pattern onto the substrate through one of the bilateral telecentric lenses;
A camera in which an image surface is arranged on a surface on which an image of a stripe pattern projected on the substrate by the other of the both side telecentric lenses is formed,
An image analysis apparatus that obtains the deformation of the substrate from the result of calculating the shape information of the substrate in pixel units by analyzing the image obtained by the camera,
Equipped with
The lattice is
Arranged so as to be tilted with respect to the optical axis of the one both-side telecentric lens at a second angle corresponding to the first angle and the magnification of the one both-side telecentric lens so as to be tilted according to the substrate plane. Is
The image plane of the camera is
Arranged so as to be tilted with respect to the optical axis of the other both-side telecentric lens at a third angle corresponding to the first angle and the magnification of the other both-side telecentric lens so as to be tilted in accordance with the substrate plane. It is,
A heater having a heating furnace that holds the substrate so that it can be heated or cooled to an arbitrary temperature,
Further equipped with,
The heating furnace of the heater,
An opening is provided on the regular reflection light receiving arrangement optical system side so as not to interfere with the optical path of the regular reflection light receiving arrangement optical system ,
Between the opening and the specular reflection light receiving arrangement optical system, the aperture and the specular reflection light receiving arrangement optical system are arranged apart from each other , and the specular reflection light receiving arrangement optical system receives heat from the heater. Heat insulation mechanism, which prevents the
Further equipped with ,
The heat insulation mechanism is
A plurality of lights provided on the optical path so as to be separated from each other so as not to interfere with the optical path of the specular reflection light receiving arrangement optical system while preventing heat from the heater from reaching the specular reflection light receiving arrangement optical system. Having a transparent member ,
Substrate shape measuring device. The opening is densely provided with a member that transmits light, or the space is left empty.
The substrate shape measuring device according to claim 1 . The heat insulation mechanism is
A plurality of light transmitting members,
A mechanism for flowing a gas between the plurality of light transmitting members,
Has,
The substrate shape measuring device according to claim 1 . The field of view of the camera and the area of the stripe pattern projected on the substrate are larger than the measurement target region on the substrate,
The board shape measuring device according to any one of claims 1 to 3 .

Images