TW201928334A - Spectral-image correlation-based confocal profilometric system and method - Google Patents

Abstract

The invention provides a confocal microscope system and method of confocal surface and internal surface profilometry using spectral image patterns, wherein a vertical scanning on each calibrated depth is performed for establishing a database having a plurality of optical diffractive spectral patterns being corresponding to each calibrated depth, respectively. A control and calculation unit is utilized in the optical system to perform normalization calculation of cross correlation between the measured diffractive spectral pattern and a plurality of calibrated diffractive spectral patterns for determining the measured depth of the tested object surface and internal (including bottom) surface position in one-shot imaging manner. Meanwhile, the diffractive spectral image pattern can be converted from its digital discrete format to an analogue continuous one by interpolating the spectral distributing characteristics of the filtering elements in the filtering module. More accurate depth information can be determined by performing the normalization calculation of cross correlation between the measured diffractive spectral pattern and a plurality of calibrated diffractive spectral patterns for determining the measured depth of the tested object surface and internal (including bottom) surface position in one-shot imaging manner.

Description

Spectral image correlation comparison type confocal topography measurement system and method

The invention relates to a confocal detection technology, in particular to a confocal system and a method for detecting a confocal surface topography which can reduce the surface vibration of an object in a measurement.

The color confocal microscopy system is one of the methods for measuring the surface topography of an object. It can measure the height, line width, groove width and depth of the mechanical or semiconductor structure, and is used as an important basis for process improvement or yield detection. . This technique was first proposed by Marvin Minsky in 1957. The principle of color confocal is to disperse the incident light to form a plurality of detection lights with different continuous depths of focus to form a measurement mechanism for optical vertical scanning. This method can be used to detect the object to be tested, and different depths can be obtained. The optical slice image is filtered by a pinhole to remove the reflected light and the scattered light outside the focus area, and the focus surface information is retained, and the optical slice image obtained by different depths is reconstructed by the computer. The three-dimensional image information of the object to be tested can be obtained.

Although the color confocal detection light can be exempted from the traditional vertical scanning because of the different continuous depth of focus, because the motion of the vertical moving mechanism causes vibration problems caused by the measuring machine, there are still several parts to be solved. :

First, the defocusing light and the stray light overlap to generate a cross talk noise problem. In the conventional technique, in order to reduce the mutual interference of light, a pinhole is often placed in front of the spectrometer. Although the method can reduce the interference, if it is applied to measure the two-dimensional surface topography of the object or requires high-resolution measurement, it needs to cooperate with the lateral movement mechanism, which will increase the time and vibration required for the measurement. The influence on the measurement accuracy, so this method is mostly applied in the field of single point measurement.

Second, the spectrometer volume takes up space and the problem of analyzing the time-consuming spectrum. In the conventional technique, in order to reduce the surface topography, it is necessary to detect the spectrum of the slit or the pinhole structure through the spectrometer, thereby finding the relationship between the wavelength and the intensity of the light corresponding to the detected position, and restoring the depth corresponding to the position. There are several ways to overcome the spectrometer. First, the spectrometer is bulky or expensive, and it takes up a lot of space. Furthermore, since the spectrometer reduces the spectral information time and does not have measurement efficiency, the main reason is that for each measurement site, the unfolded spectrum is a one-dimensional spectrum, if for a linear measurement position, the expansion Is a two-dimensional spectrum. It can be seen that each spectrometer performs one-time analysis, which is at most a linear measurement area. Therefore, if one surface is to be measured, it is necessary to scan through the lateral movement, so that not only the measurement time is increased. It is more likely that the lateral scanning motion causes vibration problems on the measuring machine, which affects the measurement accuracy.

In summary, there is a need for a spectral image correlation comparison confocal topography measurement system and method to solve the problems caused by conventional techniques.

The present invention provides a system and method for detecting a three-dimensional shape of an object surface or an internal light reflecting interface (including the back side of an object) using a confocal topography measurement technique of a spectral image pattern. The method comprises the steps of: integrating the filter component and the light intensity sensing component into an optical signal sensing device, and by using the one-shot full field of the device, the spectral composition of the measuring object light can be restored at one time. The surface topography of the object to be tested is then reconstructed to save time required for measurement and to reduce the volume of the confocal system. The technology can be applied to a microscope objective, or a dispersion objective lens, or an optical lens group composed of a display objective lens and a dispersion module.

The invention provides a confocal topography measuring system and method for applying spectral image correlation comparison type, and performs three-dimensional shape detection on an object surface or an internal light reflection interface (including a back surface of an object), and performs depth processing through depth displacement. Corresponding to the record of the spectral image pattern to create a database with a plurality of spectral image patterns. Then, according to the complex object light obtained by each sensing array, a spectral image pattern about a position is formed, and a plurality of optical comparison normalized image matching operations of the sample information are used to determine the position of the corresponding spectral image pattern. Precision depth information. Further, the spectral image pattern can be converted from a wavelength-distributed characteristic of the filter element, from a digital discrete optical map to an analog continuous optical map, and then a normalized image matching operation is performed on the measured spectral image pattern and the plurality of optical alignment sample information. To determine more precise depth information corresponding to the location of the spectral image pattern.

The invention provides a confocal topography measuring system and method for applying a spectral image correlation comparison method to detect a three-dimensional shape of an object surface or an internal light reflecting interface (including a back side of an object), which has a pixel size The digitally controlled optical switching element is used for selectively controlling the position of the incident light to be projected onto the object to be tested, thereby eliminating the lateral scanning action, not only reducing the influence of the vibration of the machine on the measurement accuracy, but also reducing the defocusing light. A noise problem that overlaps with stray light to cause cross talk.

The invention provides a color confocal system and a color confocal surface topography detecting method, which reflects light twice through a digital control unit, firstly reflects to a dispersive objective lens, and secondly reflects to a spectroscopic element and then projects to On the light sensing device. Therefore, the effect of the analog pinhole generated by the digital control unit can increase the confocal effect, that is, increase the resolution of the axial direction (depth direction).

In one embodiment, the present invention provides a confocal topography measurement system including a light source module, a microscope objective, a light sensing device, and a processing unit. The light source module is configured to provide at least one broadband modulated light. The microscope objective is used for scaling each broadband modulated light to a specific magnification and projecting onto an object, and each broadband modulated light is reflected from a specific position on the surface of the object to form a test object light. The light sensing device is configured to receive at least one of the object light reflected by the at least one specific position on the object, the light sensing device further has a filtering module having a plurality of filtering arrays for receiving the reflection At least one of the object light, each filter array has a plurality of filter elements, respectively, allowing a specific wavelength of the object light to pass through and a light sensor coupled to the filter module for sensing each filter The measured light intensity of the component produces a corresponding object optical signal to obtain a spectral image pattern. The processing unit performs a calculation on the spectral image pattern to determine depth information corresponding to a specific position of each of the object light.

In one embodiment, the present invention provides a confocal topography detection method, which includes the following steps: First, a confocal topography measurement system is provided, which has a light source, a microscope objective, and a plurality of A filter module, a light sensor and a processing unit. Then, the light source is generated by the light source to be projected to a digital control unit to generate at least one broadband modulated light. Then, each of the broadband modulated light is scaled at a specific magnification by the microscope objective and projected onto an object, and each broadband modulated light is reflected from a specific position on the surface of the object to form a test object light. Then, the filter module receives the reflected at least one object light, and filters the at least one object light, wherein each filter array has a plurality of filter elements respectively allowing a specific wavelength of the object light to pass through . The at least one object light is sensed by the light sensor to generate a spectral image pattern. Finally, the spectral image pattern is calculated by the processing unit to determine depth information corresponding to a specific position of each object light.

Please refer to FIG. 1 , which is a schematic diagram of the color confocal system architecture of the present invention. In this embodiment, the color confocal system 2 includes a light source module 20, a dispersion objective lens 21, a light sensing device 22, and a processing unit 23. The light source module 20 is configured to provide at least one broadband modulated light 200. In this embodiment, the light source module 20 has a light source 201 and a digital control unit 202. The light source 201 is used to generate a light beam 90. In an embodiment, the light beam 90 is light containing a plurality of different wavelengths, such as white light, but is not limited thereto. A collimating mirror group 203 is further disposed between the light source 201 and the digital regulating unit 202 for collimating the light beam 90 generated by the light source and projecting to the digital regulating unit 202. The digital control unit 202 has a plurality of light control switches 202a, each of which can control the direction in which the light beam is projected. In one embodiment, the digital control unit 202 is a digital micromirror device (DMD), but is not limited thereto. For example, a liquid crystal on silicon (LCOS) can also be implemented. In addition, a transmissive liquid crystal switching element, such as liquid crystal on silicon (LCOS), can also be used as an embodiment of the digital control unit 202.

As shown in FIG. 2A and FIG. 2B, the figure is a schematic diagram of the direction of the light control by the digital control unit. FIG. 2A is a perspective view of the light control switch of the digital control unit. The digital control unit 202 has a plurality of light control switches 202a, and FIG. 2A is only described in four. The light control switch 202a has at least an on state and an off state. The light control switch 202a can change the angle of its rotation through the control of the telecommunication, thereby presenting an on or off state. When light is projected onto the plurality of light control switches 202a, the path of the reflected light is determined according to the direction in which the light is deflected. In an embodiment, as shown in FIG. 2B, when the light control switch 202a is in the open state, the light reflecting element is deflected to an angle to reflect the light to the objective lens, and the light control switch 202a is in the off state. Its reflective elements reflect light to other places. The digital control unit 202 is electrically connected to the processing unit 23, and through the regulation of the processing unit 23, it can control which light control switches reflect the incident light beam 90 to the object to be tested to form a single point or multiple points, single or multiple lines, Single-area or multi-region wide-band modulated light 200.

By the characteristics of the digital control unit 202, when the correspondence between each of the light control switches 202a in the digital control unit 202 and the surface of the object to be tested is established, the on and off of the light control switch 202a can be controlled. In the (off) state, the optical path of the incident light is changed, and a plurality of broadband modulated lights 200 are formed to be projected onto the object to be tested, thereby controlling the positional order of scanning the surface of the object to be tested. In this way, the entire color confocal system 2 does not need to be moved (or scanned) in a horizontal (or lateral) direction due to changing the scanning position, for example, the machine does not move, and the object to be tested is moved horizontally (or laterally); Yes, the object to be tested does not move horizontally (or laterally), thereby eliminating the vibration or positioning error caused by the movement of the mechanism, and improving the accuracy of the measurement. Furthermore, it is also possible to avoid the noise problem of cross talk due to the overlap of the defocused light and the stray light by controlling the spatial spacing of the actuated digital control elements. For example, in an embodiment, as shown in FIG. 3A, at the first time point, the light control switch 202b reflects the broadband modulated light to the object to be tested, and at the next time point, as shown in FIG. 3B, the light control switch 202c reflects the broadband modulated light to the object to be tested. Through the light source control mode of FIG. 3A and FIG. 3B, the digital control unit 202 simulates the effect of the pinhole light source generated by the light source being projected onto the pinhole, thereby avoiding interference due to overlapping of light of adjacent point light sources.

Returning to FIG. 1A, the digital control unit 202 reflects the broadband modulated light 200 to a beam splitting element 24, and then enters the dispersing objective lens 21 via a first lens group 25 at a focus plane of the dispersing objective lens 21. Imaging. The dispersion objective lens 21 is configured to disperse each of the broadband modulated lights 200, and each of the broadband modulated lights 200 forms a plurality of detection lights 205 having different continuous depths of focus and is projected onto an object 8, which in the embodiment is The surface is perpendicular to the optical axis of the dispersion objective 21, but is not limited thereto. Each of the detection lights 205R, 205G and 205B corresponds to a wavelength. Taking the three scattered detection lights 205R, 205G, and 205B as an example, each of the dispersion detecting lights 205R, 205G, and 205B has a depth of focus, and the wavelength of the light corresponding to the surface depth of the object 8 is appropriately scanned and The information of the intensity, and then the surface topography of the object 8 is restored according to the information. The plurality of different depth detection lights 205R, 205G and 205B formed by the dispersion mechanism can replace the conventional mobile machine for vertical scanning. Therefore, it is possible to reduce the vibration or positioning error caused by the mechanism on the vertical scanning transfer table, and improve the measurement accuracy of the system. It should be noted that, using a conventional dispersion objective lens, due to the angle of reflection of the light control switch and the angle of reflection from the object to be tested or the specular surface, the light energy entering the dispersion objective lens is reduced, so that the light sensing device 22 senses the image. In the image area, there is an edge area that cannot display an image, and the brightness or saturation of the peripheral portion of the rendered image is lower than the central area (or Vignetting, phenomenon), resulting in a reduction in the effective area of the surface topography of the object. . In order to increase the amount of light entering the dispersion objective lens, the light sensing device 22 can generate a global image to solve the aforementioned halo problem. In an embodiment, the dispersion objective lens 21 can use a dispersion objective lens of a telecentric lens architecture. Further, the digital control unit 202 can be controlled to project the surface of the object at a collimated angle of incidence at the intermediate or edge light control switch to solve the problem that the image cannot be completely projected.

The object light 206 reflected by the object 8 passes through the dispersion objective lens 21, and is then projected onto the light sensing device 22 via the beam splitting element 24. In this embodiment, the light sensing device 22 is configured to receive the object light 206 reflected by the object 8. The light sensing device 22 further includes a filter module 220 and a light sensor 221. Referring to FIG. 4A and FIG. 4B, the filter module 220 has a plurality of filter arrays 222 for directly receiving the reflected object light 206. Each filter array 222 has a plurality of filter elements 223, respectively, allowing a specific wavelength. The object light passes through. In this embodiment, the filter module 220 is a Fabry-Pérot filter, that is, each filter element 223 is composed of a plurality of turns of different heights. According to the principle of Fabry-Pérot, the distance between the incident and exit surfaces of the light determines the wavelength of the outgoing light, so that the wavelength of each filter element 223 can be determined by a different height design. Taking the filter module 220 shown in FIG. 4A and FIG. 4B as an example, each filter array 222 is a 4×4 array structure having 16 filter elements 223, and each filter element 223 can correspond to a wavelength such that each filter array 222 A wide frequency range consisting of 16 wavelengths can be measured. As for the choice of wavelength, it can be determined according to the needs, and there are no specific restrictions. It is to be noted that the size of the filter array 222 is not limited to 4x4.

As shown in FIG. 1A and FIG. 4B , the photo sensor 221 is coupled to the filter module 220 for sensing the intensity of the object light passing through each filter element 223 to generate a corresponding object light. Signal to get a spectral image pattern. In this embodiment, the photo sensor 221 has a plurality of sensing arrays 224 corresponding to the plurality of filter arrays 222. Each of the sensing arrays 224 has a plurality of sensing elements 225 corresponding to the respective filtering arrays 222. Filter elements 223, each of which can sense the light intensity of the object light passing through the respective filter element 223, to generate a corresponding light intensity signal. It is to be noted that, in an embodiment, if the number of filter elements 223 of each filter array 222 is limited, for example, 16 as shown in FIG. 9A, this means that each pixel can only sense the intensity of 16 wavelengths. . As shown in FIG. 9B, wherein the X-axis is the spectral wavelength developed by one of the filter arrays 222, and the Y-axis is the light intensity sensed by the corresponding sensing array 224. Since the number of sensing wavelengths per filter array can be limited, when the filter array 222 is sensed by the corresponding sensing element 225, and the spectral response curve generated by the curve is A, the curve peak can be obtained. Corresponding to the wavelength, but in some cases, for example, as shown by curve B in FIG. 9B, when the spectrally strong response curve generated by the filter array 222 does not fall within the area covered by the sixteen wavelengths, At this point it is difficult to detect and resolve. Thus, in one embodiment, the spectral response curve formed by the filter array can be controlled by varying the number of light-controlled switches that receive the beam. For example, when only one light control switch corresponds to a filter array, not only the light sensor, such as a camera, may have a longer exposure sensing time, and may generate a curve B that is difficult to resolve, and vice versa, when the number increases, For example, when changing from 1x1 to 2x2 or 3x3, the spectral response curve C range is widened, although it affects the depth resolution and spatial resolution of the measurement, but because the spectral response curve is widened, and several known detection wavelengths The position will be mixed, that is, the corresponding light intensity can be detected, so when there are more than 3 intersections, for example, curve C and known wavelengths have three intersection points, so it is easier to reconstruct From the spectral response curve C, the wavelength corresponding to the peak of the curve C can also be found smoothly. In one embodiment, the spectral response curve can be reasonably considered to be a normal distribution curve.

It should be noted that the intensity signal sensed by each of the sensing elements 225 corresponds to the grayscale intensity of the pixel, and the number of the sensing elements 225 determines the resolution of the photosensor 221. One filter element 223 can correspond to one or more sense elements 225. The photo sensor 221 can be a CMOS sensor, a CCD sensor, or other suitable photodetector or the like. It should be noted that, in an embodiment, the photo sensor 221 of the present invention and the filter module 220 can be integrated into a single component to form an image capturing device. In addition, since the number of sensing elements 225 of the photo sensor 221 is fixed, and since each filtering array 222 corresponds to a detecting position on the object, each detecting position needs to be measured by a plurality of sensing elements 225. Therefore, measuring the object to be tested may sacrifice the resolution, but because the semiconductor process is changing with each passing day, according to the architecture of the present invention, when a higher resolution light sensing element is generated in the future, it can be used to enhance the resolution of the image.

The photo sensor 221 is further electrically connected to the processing unit 23, and the processing unit 23 calculates the spectral image pattern and the plurality of comparison sample information stored in the database to determine the depth corresponding to the specific position of the spectral image pattern. News. In one embodiment, the calculus is a normalized image matching operation. The comparison sample information may be a digital discrete ratio sample information or a calculation of the digital discrete ratio sample information via an calculus into an analog-to-continuous comparison sample information.

Please refer to FIG. 1B, which is a schematic diagram of a second embodiment of a color confocal system of the present invention. In this embodiment, the color confocal system is substantially similar to that of FIG. 1A. The difference is that the first mirror group is disposed in the embodiment, and the position of the configuration is different from that in FIG. 1A. In this embodiment, the first The mirror group 25 is disposed on the optical path between the digital control unit 202 and the light splitting element 24. In addition, FIG. 1B further has a second mirror group 26 disposed on the optical path between the beam splitting element 24 and the light sensing device 22. Since the first and second mirror groups 25 and 26 are provided in the embodiment, the first mirror group 25 is used for collimating the detection light from the digital control unit 202, and the second mirror group 26 is used to form an image. The image sensing device 22 can adjust the image size formed by the light sensing device 22 through the first and second mirror groups 25 and 26.

In addition, please refer to FIG. 6, which is a schematic diagram of another embodiment of the color confocal system of the present invention. In this embodiment, substantially similar to the embodiment of FIGS. 1A and 1B, the difference is that in the embodiment, the light splitting element 24 is disposed between the light source 201 and the digital control unit 202, wherein the broadband modulated light 200 is split by the light splitting element. 24 is directed to the digital control unit 202. In this architecture, the beam 90 is directed by the beam splitting element 24 to the digital control unit 202. The broadband modulated light 200 refers to light emitted by the 202, which passes through the first mirror 25 The broadband modulated light 200 is collimated and projected onto the dispersion objective lens 21. In addition, the object light 206 reflected by the surface of the object 8 is projected onto the digital control unit 202 for a second time through the original optical path, and the digital control unit 202 reflects the object light 206 to the light splitting element 24, and the light splitting element 24 will The object light reflected by the digital control unit 202 is guided to the second mirror group 26 and then projected onto the light sensing device 22. 1A and 1B, in the embodiment of FIG. 6, the digital control unit 202 reflects the light twice, first to the dispersive objective lens 21, and the second time to the spectroscopic element 24 and then to the light. On the sensing device 22. Therefore, the effect of the analog pinhole generated by the digital control unit 202 can increase the confocal effect, that is, increase the resolution of the axial direction (depth direction).

1A-1B and FIG. 6 are embodiments for measuring the surface topography depth of an object, but the technique for reducing the topography of the surface to be measured by using the diffraction pattern according to the present invention is not limited to measuring the shape of the surface of the object. In another embodiment, the light source that is penetrating is projected onto the object to be tested, and the topography of the light reflecting interface (including the back side of the object) inside the object to be tested is measured. The inside can be the lower surface of the object to be tested in contact with the carrier, or the structural surface inside the object to be tested, such as a defect or a hollow structure, as shown in FIG. 1C. In this embodiment, the structure of FIG. 1A is used. The optical system architecture is used to illustrate that the incident light generated by the light source in the embodiment is a light source having transparency to the object to be tested. In an embodiment, for example, the light source is selected from infrared light, and the object to be tested is a germanium wafer. Under this structure, the object to be tested 8a is penetrated and reflected on the bottom surface of the object to be tested 8a to form the object light 93a, and then reflected through the dispersion objective lens 21 to form a bottom surface corresponding to the object to be tested on the light sensing device 22. Diffraction image of depth of appearance. In addition, in another embodiment, in the object to be tested 8a, if there is a crack or an inner layer hollow structure 83, the incident light is reflected on the crack surface or the hollow structure surface to form the object light 93b, and A spectral image pattern corresponding to the surface of the crack or the surface of the inner structure is produced on the light sensing device 22. It is to be noted that although FIG. 1C is illustrated by the optical system of FIG. 1A, the optical system is not limited in use, and the optical systems of FIGS. 1B and 6 can also be applied.

Next, the principle of the spectral image pattern of the present invention will be described. Optically, Fraunhofer diffraction, also known as far-field diffraction, is a kind of wave diffraction which occurs when electromagnetic waves pass through pinholes or slits. This results in a change in the size of the observed image due to the far field position of the observation point and the fact that the diffracted wave passing through the pinhole has a progressive plane wave. In the present invention, since the distance from the point light source generated by the digital regulating unit 202 to the object to be tested 8 is much larger than the size of the point light source generated in the digital control unit 202, for example, the size of the 2x2 light control switch, it is applicable to The principle of Lang and Fei diffraction.

In an embodiment, since the array of light control switches 203 that generate point sources in the digital control unit 202 can be regarded as a rectangular point source, it can be analyzed using the architecture shown in FIG. 1D. In Fig. 1D, S represents a point source plane, wherein the shaded area represents the light control switch 203b that reflects light to another location, and the blank area represents the light control switch 203a that reflects light to the dispersion objective 21. Therefore, the blank area can be regarded as a rectangular point source. S' represents the plane of the spectral image pattern. According to the above structure, the light field u(x, y, z) of each position P on the spectral image pattern generated on the S' plane through the point source can be expressed as Equation (1): ..... (1) where z is the distance from the point source to the optical diffraction pattern plane S', A is the source amplitude, and a, b is the size of the rectangular point source representing the blank area. When the origin is changed to the center position of the rectangular point source, the result of integration can be obtained as shown in equation (2): ..... (2) where As shown in the following formula (3): ..... (3) where As shown in the following formula (4): ..... (4) where Represents the optical diffraction angle along the Y direction. According to the architecture of FIG. 1A, when the distance between the object to be tested and the light source changes, different in and out focus spectral image patterns are captured by the light sensing device 22, and each position on the spectral image pattern The intensity distribution is as shown in equation (5): ..... (5)

Returning to FIG. 1A, the processing unit 23 can determine each point light source (wideband modulated light 200) on the surface of the object to be tested 8 according to the spectral image pattern of the object 8 to be tested and the comparison sample information in the database. The depth of a specific position projected onto the surface of the object to be tested 8. That is, a plurality of comparison sample information corresponding to different known depths are stored in the database electrically connected to the processing unit 23. In another embodiment of the database, the database stores therein a plurality of comparison sample information corresponding to a known depth of the position of the broadband modulated light 200 produced by the single or plurality of light control switches 202a in the digital control unit 202. The light sensing device 22 generates a spectral image pattern having a plurality of sub-spectral image patterns corresponding to the broadband modulated light 200 at different positions, so that the processing unit 23 maps each sub-spectral image pattern to the database. The normalized cross-correlation (NCC) calculation is performed on the plurality of comparison sample information corresponding to the position of the same point source, and the processing unit 23 may determine the depth of the position of the object to be tested corresponding to the position of the point source according to the calculation result. The algorithm is to calculate the light intensity I _b corresponding to the different filter elements 223 in each sub-spectral image pattern and the image light intensity R _b of the corresponding filter element 223 in each of the corresponding sample information. In an embodiment, the noise parameter may be further included, and the calculation formula is as shown in the formula (6): (6) where b is the wavelength corresponding to each of the filter elements, and I is the spectral intensity of the extracted spectral image pattern, that is, I _b refers to the sensing of the corresponding different filter elements 223 in each of the sub-spectral image patterns. The intensity of the light, R is the light intensity of the comparison sample information, that is, R _b is the image light intensity of the corresponding filter element 223 in each of the corresponding sample information, and n _I is the impurity of the captured spectral image pattern. News, n _R is the noise in the sample information.

In another embodiment, after capturing a spectral image pattern, the processing unit 23 changes the position of the point source, and each time it is changed, another spectrum image pattern is obtained, and the plurality of optical comparison samples with the position of the corresponding point source are compared. The information is calculated to obtain the depth information of the position of the point light source correspondingly changed on the surface of the object to be tested. After the spectral image pattern of a plurality of positions on the surface of the object or the internal light reflection interface is collected, and the depth information is calculated, the three-dimensional shape of the surface of the object to be tested can be reconstructed. It should be noted that whether to change the position of the point source by using the digital control unit 202 may be determined according to the resolution of the reconstructed image. If the number of point sources is sufficient, and the resolution required for the detection is sufficient, the unimorphism may be used. Capture the image. In addition, for the control mode of switching the position of the point light source multiple times, since the position of the point light source is changed by controlling the light control switch, the detection speed of the image capturing device is larger than that of the image capturing device, so the image capturing device detects The faster the rate, the faster the scanning of the surface of the object or the internal light reflecting interface can be done. Through such a scanning method, the mechanism of the horizontal scanning can be avoided, thereby reducing the interference of the vibration in the measurement, and improving the speed and accuracy of the surface three-dimensional shape detection.

Referring to FIG. 7, the method of surface topography detection using the aforementioned color confocal system is described. In this embodiment, taking the architecture of FIG. 1A as an example, the detecting method 4 first performs step 40 to establish a database, which is a database with complex comparison sample information. In this embodiment, the comparison sample information The plurality of spectral image patterns are comparison sample information corresponding to at least one wavelength of light. The database for establishing the optical comparison sample information includes the following steps. As shown in FIG. 5, a plane mirror 80 is first placed on the carrying platform 27, and then the light source module 20 generates at least a light source, which is white light. The light source is projected onto the plane mirror 80 via the color objective lens. In the embodiment of the present step, a plurality of two-dimensional arrays of point light sources are illustrated, that is, a plurality of incident lights reflected by the digital control unit 202 to the objective lens 21 are reflected from the plane mirror 80 to the light sensing device 22 . on. Then, the light sensing device 22 is controlled to capture an image. It should be noted that, since the embodiment has a plurality of point light sources, the generated single spectral image pattern has a plurality of sub-spectral image patterns corresponding to each of the point light sources. The position of each of the sub-spectral image patterns is then associated with the position of the photo-controlled switch of the digital control unit 202. In an embodiment, since the light sensing device 22 of the embodiment has a filter element of 16 wavelengths, the single spectral image pattern can be further divided into 16 images of different wavelengths, and the image with the highest contrast is used. Perform a positional correlation calculation.

Next, the plane mirror 80 is depth scanned and an optical diffraction image of a corresponding depth is captured. Each depth h ₀ ~ h _n takes a corresponding spectral image pattern, and each spectral image pattern has a plurality of sub-spectral image patterns corresponding to the position of the point source. For example, after the image capturing device 22 captures the spectral image pattern about the current plane position h ₀ , then changes the position h _{0 of} the plane mirror to h ₁ , for example, through the piezoelectric element (PZT) to the next position. After h ₁ , continue to capture the spectral image pattern of the changed position. Due to the defocusing effect of the optical confocal, the sub-spectral image pattern produced by each point source at each depth position is unique. After changing the depth position of the plane mirror from h ₀ to h _n , that is, when all depths of the corrected depth range are completed, a plurality of sub-spectral image patterns corresponding to different known depths may be obtained corresponding to the position of each point source. These sub-spectral image patterns can be used as optical comparison sample information for judging the surface depth of the object to be tested in the future. Therefore, the database stores a plurality of comparison sample information about the position of the point source generated by the plurality of corresponding digit adjustment units 202. The comparison sample information generated in the embodiment belongs to the digital discrete optical spectrum.

Next, in step 41, the light source 201 in the light source module 20 is controlled to generate a light beam 90 that is projected to the digital control unit 202 to generate at least one broadband modulated light 200. In order to avoid the generation of interference between the light, in an embodiment, as shown in FIG. 3A, the light control switch 202b at a specific position of the digital control unit 202 may be first reflected to the dispersion objective lens to form a plurality of broadband modulated lights. A wide frequency modulated light has an appropriate spacing between the plurality of analog point sources to avoid lateral interference. It should be noted that the size of the point source may be determined according to requirements, and is not limited to the single light control switch 202b shown in FIG. 3A. As shown in the foregoing relationship of FIG. 9B, in step 41, there is further included a step of changing the number of the photo-controlled switches that receive the light beam, thereby controlling the spectral response curve formed by the filter array. It should be noted that the step of changing the number of the light control switches receiving the light beam is not a necessary structure, that is, when the technological evolution increases the number of filter elements of each filter array, it is not necessary to use the foregoing knowledge. The way to adjust the width of the spectral response curve.

Next, step 41 is performed to pass the multi-channel wide-band modulated light 200 through the dispersion objective lens 21 to disperse each of the broadband-modulated lights 200. Since the broadband modulated light 200 is a light composite having a plurality of different frequencies, each of the broadband modulated lights 200 after dispersion forms a plurality of detection lights 205R, 205G, 205B having different continuous depths of focus and is projected onto the object 8, each of which is projected onto the object 8, each A detection light 205R, 205G, 205B corresponds to a wavelength. Moreover, since the depth of focus of each of the detecting lights 205R, 205G, and 205B is different, after detecting a specific position on the object 8, the detected light corresponding to the depth of the position has the maximum light intensity after the reflection. The object light 206 corresponding to the plurality of detection lights 205R, 205G, and 205B reflected by the object is reflected by the beam splitting element 24, and is projected to the integrated filter module 220, and the light sensor 221 Measuring device 22.

Next, proceeding to step 42, the plurality of object light 206 is filtered by the filter module 220. It is to be noted that, since the filter module 220 has a plurality of filter arrays, and each of the filter arrays has a plurality of filter elements respectively allowing a specific wavelength of the object light to pass through, in an embodiment, the appropriate design can be adopted. Each filter array corresponds to each of the object light, and a wavelength range covered by the plurality of filter elements in each filter array corresponds to a wavelength range of the broadband modulated light. Through such a design, as shown in FIG. 8, the reflected object light 206 can be passed through the corresponding filter array 222, and each of the filter elements 223 can filter the passing object light 206.

After passing through the filter element 223, step 43 is followed to cause the photosensor to sense the light intensity of each of the object light passing through the filter element. As shown in FIG. 8 , since the photo sensor 224 is composed of a plurality of photo sensing elements 225 , in the embodiment, each of the photo sensing elements 225 corresponds to one filter element 223 , but not limited thereto. For example, in another embodiment, each filter element may also correspond to a plurality of light sensing elements. For example, each of the light sensing elements 225 corresponds to one filter element 223. Each of the light sensing elements 225 can sense the light of the object passing through the corresponding filter element 223, thereby sensing the light intensity of the corresponding object light 206. . In FIG. 8, reference numeral 7 represents the object light passing through a plurality of filter elements 223 in each filter array 222, and the light intensity, the plurality of light intensities 70a, and the information corresponding to the wavelength of the object light are transmitted to the object. Processing unit 23.

Next, in step 44, the processing unit 23 forms an image having a spectral image pattern according to the plurality of object light intensity signals (16 in this embodiment) obtained by each sensing array. In this step 44, since the signal generated in step 43 is transmitted to the processing unit 23, the processing unit 23 can generate an image of the spectral image pattern based on the returned light intensity signal. Referring to FIG. 1A and FIG. 8 , for the detection position A, the corresponding filter array 222 detects 16 light intensities 70 a , each of which corresponds to a wavelength, and thus is in a spectral image pattern. The filter element 223 of each filter array 222 in the image will have a light intensity I _b .

Then, in step 45, a normalized cross correlation calculation method, such as a normalized cross correlation calculation method, is used to determine the depth of the point source generated by the corresponding light control switch on the object to be tested. In this step, first, the sub-spectral image pattern corresponding to the position of the point source generated by the photo-control switch is found from the spectral image pattern, and then the plurality of sub-spectral image position points corresponding to the sub-spectral image pattern are selected from the database. Comparing the sample information, each comparison sample information corresponds to a known depth. Next, according to the above equation (6), a plurality of light intensities I _b corresponding to each of the filter elements 223 are extracted from the measured spectral patterns corresponding to each of the filter arrays 222. It should be noted that, in this embodiment, each filter array 222 has 16 filter elements whose wavelength ranges from 465 nm to 630 nm, but is not limited thereto. In one embodiment, the 16 wavelengths are respectively a combination of wavelengths as shown in FIG. 9A, but are not limited thereto.

And measuring a plurality of different light intensities I _b obtained by each sub-spectral image pattern according to formula (6), and corresponding to each of the depth positions, the corresponding plurality of light intensities R of the sample information _b Performing a calculation to calculate a normalized cross correlation (NCC) of the sub-spectral image pattern of the measurement and each of the aligned sample information. As shown in FIG. 10, reference numeral 50 denotes a spectral image pattern of a measuring instrument corresponding to a filter array generated by the light sensing device, that is, a reflection of a specific position on the surface of the object to be tested reflected by a point light source. The sub-spectral image pattern is measured, and the reference numerals 511 to 511n represent a plurality of comparison sample information 511~511n corresponding to the position of the point source in the database, and each comparison sample information 511~511n corresponds to a known depth. In this embodiment, the measured sub-spectral image pattern 50 has 16 light intensities I _b , and the optical intensity value R _b corresponding to each optical comparison sample information is calculated by using equation (6) to obtain an NCC. value. Therefore, the sub-spectral image pattern 50 can obtain a plurality of NCC0~NCCn values after calculating the sample information 511~511n with the plurality of sheets. Since each comparison sample information 511 to 511n corresponds to a depth, each NCC value also corresponds to a depth. By a plurality of NCC values NCC0~NCCn and their corresponding depths, a normalized mutual interaction as shown in FIG. 11 can be constructed. Correlation value versus depth curve. It can be seen from the curve that it has a maximum value which represents the closest of the sub-spectral image pattern of the object to be tested and the comparison sample information corresponding to the NCC value. Therefore, the last step 45 is to find the maximum NCC value from the plurality of NCC values NCC0~NCCn, and use the depth value corresponding to the sample information corresponding to the NCC value as the object to be tested. The depth of the position of the sub-spectral image pattern should be. Taking FIG. 11 as an example, it is a normalized cross-correlation value (NCC) and a depth relationship curve obtained by the calculation of FIG. As can be seen from Fig. 11, the NCC value is the largest at a depth of 90 μm, so that it can represent the position of the sub-spectral image pattern 50 on the surface of the object to be tested, and its depth is 90 μm. Similarly, the sub-spectral image patterns corresponding to other point sources are also found to have corresponding depths according to the foregoing manner. Finally, according to the depth corresponding to the position of the plurality of point light sources, the single-layer spectral image pattern capture can be used to perform the whole-surface shape measurement scan of the surface of the object or the internal light reflection interface, thereby completely reconstructing the surface of the object to be tested. Two-dimensional or three-dimensional shape.

In addition, it should be noted that if the measurement resolution is to be increased, the position of the point source may be changed again in step 46, as shown in FIG. 3A, wherein at the first time point, the light control switch of the digital control unit 202 When the 202b is in the on state, the light is guided to the objective lens, and when the light control switch 203a is turned off, the light is guided to another place. When the spectral image pattern is captured, the processing unit 23 controls the digital control unit 202 to change the position of the point source to form a state as shown in FIG. 3B, so that depth measurement can be performed on different positions of the object to be measured to improve Resolution.

In another embodiment, since the step 45 normalizes the image matching operation to the sub-spectral image pattern obtained by the corresponding single filter array, the resolution is determined by the size of the rate wave array. Since each spectral pattern has 16 wavelengths in this embodiment, if the accuracy of the measurement is to be increased, there are two ways, one is to increase the matrix of each array module, for example, to 10x10 or 20x20, etc., One way is to perform calculations by using sub-spectral image patterns generated by other filter arrays in the periphery to form a larger filter array. Taking FIG. 10 as an example, the spectral image patterns (hatched areas) surrounding the measurement sub-spectrum image pattern 50 are combined into a 3×3 sub-spectral image pattern. In another embodiment, it can also be expanded outward to a size of 5x5, depending on the needs. It should be noted that, taking 3x3 as an example, corresponding to the size of the spectral image of the measurement sub-spectrum, the optical comparison sample information is also used in step 40 to adopt the corresponding size. The manner of establishment is similar to the foregoing step 40. The difference is that the image captured for each depth is not a sub-spectral image pattern generated by a single filter array, but a sub-spectral image pattern generated by 3×3 filter arrays.

It should be noted that the foregoing measurement sub-spectrum image pattern 50 and the optical comparison sample information in the database are spectral image patterns belonging to the digital discrete optical spectrum, and the 4×4 filter array 222 is taken as an example, mainly because the filter array 222 can 16 wavelengths are allowed to pass and are sensed by the photo sensor 221. In order to increase the depth (longitudinal) resolution, in another embodiment, data fitting and subtraction can be performed on the discrete optical map, and the discrete optical map is converted into an analog continuous optical map. A schematic diagram of another embodiment of a process for detecting a surface topography performed by the color confocal system of the present invention shown in FIG. 12A is taken as an example. In the process 4a, steps 41a-44a and 46a are similar to FIG. The difference is that in the step 40 database shown in FIG. 7, which is a database having a plurality of discrete ratios of sample information, and in the database established in step 40a in this embodiment, the ratio is The sample information is a plurality of analog continuous optical maps corresponding to different light source positions and different depths; and step 45a of the present embodiment uses the analog continuous optical map to perform depth position calculation.

As shown in FIG. 12B, the process of establishing the analog optical pattern in step 40a is first described. First, a spectral correction matrix is established in step 401. In this step, a calibration procedure is performed for each group of filter arrays 222, and the calibration procedure is A monochromator is used to generate discrete spectra with a wavelength range of 400-1000 nm and a spacing of 1 nm. Let the discrete spectrum generated by the monochromator pass through each filter element 223 of each set of filter arrays 222, measure the quantum efficiency (QE) of the single filter element 223 for each wavelength, and integrate the quantum efficiency of each wavelength into The quantum efficiency curve of a filter element 223, as shown in Figure 13, is the quantum efficiency curve produced by a single filter element 223 for a wavelength range of 400-1000 nm. Therefore, for each filter array 222, each filter element has a quantum efficiency curve, and the entire quantum efficiency curve is integrated to form a spectral correction matrix of the filter array, and the structure thereof is as shown in the following formula (7). ....(7) The row of this matrix represents the filter element, and each row represents the quantum efficiency of each filter element for each wavelength λ ₁ ~λ _n , taking a 4x4 filter array as an example. The matrix of (7) is a matrix of 16*600. It should be noted that the spectral wavelength range in which the spectral correction matrix is generated is not limited to 400 to 1000 nm, and may be determined according to requirements. For example, the matrix may be established directly according to the wavelength range of the filter array, for example, 465 to 630 nm.

Next, in step 402, the value in the effective wavelength range of the corresponding filter array is taken out from the spectral correction matrix (7), which is selected according to the wavelength range of the selected filter array. The effective range of the filter array in this embodiment is 465-630 nm. Next, in step 403, for each filter element, the quantum efficiency value of each wavelength is divided by the sum of the quantum efficiencies in the effective range, and the contribution ratio of each wavelength to its quantum efficiency can be obtained. Then, step 404 is performed, and the ratio of the light intensity measurement value corresponding to each filter element in each comparison sample information obtained in step 40a is multiplied by the corresponding quantum efficiency contribution ratio distribution. The continuous quantum efficiency through this filter element is obtained. Finally, in step 405, the quantum efficiencies of each filter element corresponding to each wavelength in the 465-630 wavelength range are added in each filter array, and the analog continuous spectrum of the filter array can be obtained in combination. Taking FIG. 14 as an example, for convenience of explanation, FIG. 14 is explained by a 2×2 filter array 222a. As shown in FIG. 14, the contribution ratio distribution curve of the quantum efficiency corresponding to each filter element 223b is wavelength 0 to wavelength 3. Adding the quantum efficiency ratio (%) of the Y coordinate corresponding to the wavelength 0 to the wavelength 3, the analog continuous spectrum of the corresponding filter array 222a is obtained. Similarly, back to the 4x4 filter array, there will be 16 sets of quantum efficiency contribution ratio distributions. After addition, the analog continuous spectrum of the corresponding information samples of each filter array will be obtained. Therefore, each of the comparison sample information of the different known depths corresponding to each light source in the database can be converted into an analog continuous spectrum map corresponding to each different known depth through the processing of 401 to 405 described above.

After the continuous spectral map information is established in step 40a, the detection process of steps 41a to 44a is also performed, which is described in FIG. 7 and will not be described herein. Next, in step 45a, an image having a spectral image pattern formed by the light intensity information obtained in step 44a and an analog continuous spectrum corresponding to the different depth positions obtained in step 40a are calculated. In step 45a, the digital discrete spectral image pattern obtained in step 44a and the spectral correction matrix of equation (7) are first calculated to be converted into an analog spectral image pattern. Taking a filter array as an example, in the obtained filter array, after the light intensity information of each filter component is obtained, that is, the sub-spectral image pattern corresponding to the filter array is obtained from the spectral image pattern, and the sub-spectral image pattern is obtained in the sub-spectral image pattern. Each light intensity is calculated by the spectral correction matrix of equation (7), and 16 calculation results are obtained. When the 16 calculation results are added, a quantitative analog spectrum of the corresponding filter array is obtained. Then, a normalized image matching operation is performed, and the at least one sub-spectral image pattern corresponding to the light position of the object, that is, the aforementioned analog analog continuous spectrum map, is taken out from the analog spectral image pattern. The normalized cross-correlation spectrum (NCC) calculus is performed on the analog continuous spectrum map of the measurement and the analog continuum spectral samples of each known depth corresponding to the position of the filter array in the database established in step 40a, and then The known depth corresponding to the analog continuum spectral sample with the largest value is selected from the plurality of calculated values, and most corresponds to the depth of position detected by the filtering array. Since there are a plurality of filter arrays, each filter array corresponds to one detection light source. Therefore, through the foregoing method, a single-time spectral image pattern capture can be performed to perform a full-scale topographic measurement scan of the surface of the object or the internal light reflection interface. And then completely reconstruct the two-dimensional or three-dimensional shape of the surface of the object to be tested.

In the foregoing embodiment, the dispersion objective lens may be a general microscope objective with a dispersion module to disperse light. The dispersion module can be a diffractive optical element (DOE) or a dispersive mirror group.

In addition, in another embodiment, as shown in FIG. 15, in this embodiment, substantially similar to FIG. 1A, the difference is that the dispersion objective lens 21 in FIG. 1A is changed to the microscope objective lens 21a of FIG. For example, the dispersive objective lens 21 is replaced by a microscopic objective lens, and the digital control unit 202 reflects the broadband modulated light 200 to a beam splitting element 24, and then scales each broadband modulated light 200 by a microscope objective 21a at a specific magnification. The formed detection light 205 is projected onto the object 8, and each of the detection light 205 is reflected from a specific position on the surface of the object 8 to form the object light 206, and the focus plane of the microscope objective 21a. Imaging. Each of the broadband modulated lights 200 is focused and projected onto an object 8, and the object 8 is vertically scanned using a vertical displacement stage 27, i.e., the distance between the object 8 and the microscope objective 21a is varied. Each depth position of the vertical scan obtains the object light 206 reflected by the surface of the object 8, and is received by the photo sensor 22 as a spectral image pattern, so each spectral image pattern corresponds to a scanned depth position. Since the general microscope objective 21a is used as the component for focusing light, the spectral image pattern reflects the spectral image pattern of focus and out of focus in accordance with the position of the vertical scan. After the vertical scanning, the depth information corresponding to the focused spectrum image is obtained, and the measurement effect can be achieved. In one embodiment, the depth information is obtained by comparing the spectral image sensed by the light sensor 22 with the data library, or in another embodiment, after the vertical scanning. In the spectral image pattern, the focused spectral image pattern is identified by the light intensity or other spectral features, and the depth position corresponding to the focused spectral image pattern is used as the depth information corresponding to the detected light on the object.

Traditionally, a microscopic objective lens is used to perform depth scanning of a conventional image capturing device, such as a CCD or CMOS camera, to obtain images of different depths, and each image corresponds to the same depth scanning position. The focal depth curve of a single wavelength and light intensity, as shown in FIG. 16 , is a graph showing the relationship between the spectrum and the light intensity of the image obtained by the depth of focus obtained by conventional depth scanning. In FIG. 16 , the focused image in the depth scan is shown in FIG. 16 . It has a peak value, but due to the image or interference of the noise, the curve often has noise. As shown in the area D, these noises will affect the judgment of the peak value, and thus the result of judging the focus image or the out-of-focus image.

In contrast, using the light sensing device of the present invention, as in the architecture of FIG. 15, the filter module has a plurality of filter arrays for receiving reflected at least one object light, each filter array having a plurality of filter elements, Therefore, when performing the depth scan, for each detected position, a relationship curve between the spectral wavelengths of the plurality of filter elements and the light intensity can be obtained, as shown in FIG. In Fig. 17, at a specific detection position, there are a plurality of spectral wavelengths and light intensity curves, each of which corresponds to a filter element. Since there are a plurality of curves, in the image of the plurality of depth scans for the specific detection position, it is predicted whether the image is a focused image or an out-of-focus image, and can be formed by a plurality of curves as shown in FIG. A variety of rich information, in order to get more accurate, stable and reliable focus or out of focus judgment results.

The above description is only intended to describe the preferred embodiments or embodiments of the present invention, which are not intended to limit the scope of the invention. That is, the equivalent changes and modifications made in accordance with the scope of the patent application of the present invention or the scope of the invention are covered by the scope of the invention.

2‧‧‧Color confocal system

20‧‧‧Light source module

200‧‧‧Broadband modulated light

201‧‧‧Light source

202‧‧‧Digital Control Unit

203‧‧‧ collimating mirror

202a, 202b, 202c‧‧‧ light switch

205‧‧‧Detecting light

205R, 205G, 205B‧‧‧Detecting light

206‧‧‧Measure light

21‧‧‧Dispersive objective

21a‧‧‧Microscope objective

22‧‧‧Light sensing device

220‧‧‧Filter module

221‧‧‧Light sensor

 222, 222a‧‧‧Filter array

223, 223a, 223b‧‧‧ filter components

224‧‧‧Sensor array

225‧‧‧Sensor components

23‧‧‧Processing unit

24‧‧‧Spectral components

25‧‧‧ first mirror

26‧‧‧Second mirror

27‧‧‧Loading station

4‧‧‧ Surface topography detection method

40~46 steps

4a‧‧‧ Surface topography detection method

40a~46a steps

50‧‧‧Spectral imagery

511~511n‧‧‧Comparative sample information

7‧‧‧Light intensity array

70, 70a‧‧‧ light intensity

8‧‧‧ objects

90‧‧‧ Beam

A‧‧‧Detection location

93a‧‧‧Measurement light

93b‧‧‧Measurement light

1A is a schematic view showing a first embodiment of a color confocal system architecture of the present invention. FIG. 1B is a schematic diagram of a second embodiment of a color confocal system architecture of the present invention. 1C is a schematic view of a third embodiment of a color confocal system architecture of the present invention. FIG. 1D is a schematic diagram illustrating the diffraction of Frang and Fiji. 2A and 2B are schematic diagrams showing the direction of light control by a digital control unit. 3A and 3B are schematic diagrams showing changes in scanning position by a digital control unit. 4A and 4B are schematic diagrams of a filter module and a filter array. Figure 5 is a schematic diagram of establishing a database to change the measurement depth. 6 is a schematic view of another embodiment of a color confocal system of the present invention. FIG. 7 is a schematic flow chart of a surface topography detecting method performed by the color confocal system of the present invention. FIG. 8 is a schematic diagram of filtering and sensing light intensity of the light sensing device of the present invention. Figure 9A is a schematic illustration of the wavelengths corresponding to each of the filter elements in the filter array. Figure 9B is a schematic diagram of the spectral response curve of the object light passing through each of the filter arrays. FIG. 10 is a schematic diagram showing the relationship between a sub-spectral image pattern in a spectral image pattern and a corresponding plurality of optical alignment sample information. Figure 11 is a schematic diagram of a normalized cross-correlation value (NCC) versus depth curve. 12A is a schematic diagram of another embodiment of a process for detecting a surface topography performed by a color confocal system according to the present invention. 12B is a schematic flow chart of an embodiment of establishing an analog continuous optical spectrum according to the present invention. Figure 13 is a graph of the quantum efficiency produced by a single filter element over a wavelength range of 400-1000 nm. Figure 14 shows the contribution ratio distribution curve of the quantum efficiency corresponding to each filter element. FIG. 15 is a schematic diagram of another embodiment of a confocal topography measurement system architecture of the present invention. Fig. 16 is a graph showing the relationship between the spectrum and the light intensity of the image obtained by the depth of focus obtained by conventional depth scanning. Fig. 17 is a graph showing the relationship between the spectrum and the light intensity of the image obtained by the depth of focus obtained by the depth scan of the present invention.

Claims (23)

A confocal topography measuring system includes: a light source module for providing at least one broadband modulated light; and a microscope objective for scaling each broadband modulated light to a specific magnification and projecting onto an object Each broadband modulated light is reflected from a specific position on a surface of the object to form a test object light; a light sensing device for receiving at least one of the object light reflected by the at least one specific position on the object, The light sensing device further has: a filter module having a plurality of filter arrays for receiving the reflected at least one object light, each filter array having a plurality of filter elements respectively allowing a specific wavelength of the object light And a light sensor coupled to the filter module for sensing a measured light intensity of each filter element to generate a corresponding object light signal to obtain a spectral image pattern; The processing unit performs a calculation on the spectral image pattern to determine depth information corresponding to a specific position of each of the object light. The confocal topography measuring system of claim 1, wherein the light source module further comprises: a light source for generating a broadband incident light; and a digital control unit for injecting the broadband Light is modulated into the at least one broadband modulated light and projected onto the microscope objective. The confocal system according to claim 2, wherein the digital control unit has a plurality of light control switches, and the analog light source is projected to the pinhole by controlling ON or OFF of at least one light control switch at a specific position. Single or multiple pinhole light source effects produced. The confocal system of claim 2, wherein the light source module further comprises: a light splitting element disposed on an optical path between the digital control unit and the microscope objective; and a first lens group It is selected to be disposed between the digital control unit and the light splitting element or on an optical path between the light splitting element and the microscope objective. The confocal topography measuring system of claim 4, wherein the light source module further comprises a second mirror group disposed between the beam splitting element and the photo sensor. The confocal system of claim 2, wherein the light source module further comprises: a light splitting element disposed between the light source and the digital control unit; a first mirror set disposed in the An optical path between the digital control unit and the microscope objective; and a second lens group disposed on the optical path between the light splitting element and the light sensor. The confocal topography measuring system of claim 6, wherein the digital control unit projects the at least one broadband modulated light onto the microscope objective, and the object light passes through the microscope objective to be digitally The control unit is reflected to the light splitting element, and the light splitting element projects the light of the test object to the light sensor. The confocal system of claim 1, wherein the processing unit intercepts, in the calculation, a sub-spectral image pattern of the position of each of the object light in the spectral image pattern, and the plurality of Performing operations on the sample information such that each sub-spectral image pattern generates a plurality of normalized cross-correlation values relative to the plurality of comparison sample information, the processing unit aligning the samples corresponding to the largest normalized cross-correlation values The known depth corresponding to the information is the depth information of the specific position corresponding to the object light corresponding to the sub-spectral image pattern. The confocal topography measurement system of claim 1, wherein the filter module is a Fabry-Pérot filter, wherein each filter element has a different thickness. The confocal topography measurement system of claim 9, wherein the filter module and the photosensor are integrated into an optical sensing device. The confocal topography measurement system of claim 1, wherein the comparison sample information is a digital discrete optical spectrum or an analog continuous optical spectrum, wherein the spectral image pattern is a digital discrete spectral image pattern or A class of continuous spectral image patterns. For example, the confocal topography measurement system described in claim 1 further performs a vertical scan, wherein the spectral image pattern is a spectral image pattern corresponding to different vertical depths after vertical scanning, each correspondingly different. The depth spectral image pattern has a light intensity. The confocal topography measuring system according to any one of claims 1 to 11, wherein the microscopic objective lens is a dispersive objective lens or the microscopic objective lens further has a dispersion module for each broadband Modulating the light dispersion, each broadband modulated light forming a plurality of detected lights having different continuous depths of focus and projecting onto the object, each detected light corresponding to a wavelength, each broadband modulated light being specific from the surface of the object The positional reflection forms the object light. The confocal topography measurement system of claim 13 or claim further has a database having a plurality of comparison sample information, each comparison sample information corresponding to a known depth, the processing unit And performing the calculation on the spectral image pattern and the plurality of comparison sample information to determine depth information corresponding to a specific position of each of the object light. The confocal topography measurement system of claim 13, wherein the dispersive objective lens is a dispersive objective lens of a telecentric lens architecture. A confocal topography detecting method includes the following steps: providing a confocal topography measuring system having a light source, a microscope objective, a filter module having a plurality of filter arrays, and a light perception a detector and a processing unit; generating a light beam from the light source to a digital control unit to generate at least one broadband modulated light; and using the microscope objective to scale each broadband modulated light to a specific magnification and project it onto an object Each broadband modulated light is reflected from a specific position on a surface of the object to form a test object light; the filter module receives at least one of the reflected object light, and filters the at least one object light. Wherein each filter array has a plurality of filter elements respectively allowing a certain wavelength of the object light to pass; the at least one object light is sensed by the light sensor to generate a spectral image pattern; and the processing unit The spectral image pattern is calculated to determine depth information corresponding to a particular location of each of the object lights. The method for detecting a confocal surface topography according to claim 16 of the patent application has a database having a plurality of comparison sample information, each comparison sample information corresponding to a known depth, the processing unit And performing the calculation on the spectral image pattern and the plurality of comparison sample information to determine depth information corresponding to a specific position of each of the object light. The confocal topography detecting method according to claim 17, wherein the specific position is a position of a surface, an inner surface or a bottom surface of the object, and determining depth information of each specific position further comprises the following steps: A normalized image matching operation is performed by extracting at least one sub-spectral image pattern corresponding to the light position of the object from the spectral image pattern, and performing a plurality of comparison sample information in each sub-spectral image pattern and the database. Computing to generate a plurality of cross-correlation values for comparing sample information; and using a known depth corresponding to the comparison sample information corresponding to the maximum value of the plurality of cross-correlation values as a specific position corresponding to the sub-spectral image pattern Depth information. The confocal topography detecting method according to claim 17, further comprising the step of establishing a spectral correction matrix for each filter array, and comparing the spectral correction matrix with each of the sample information. A conversion calculus is performed to convert each of the aligned sample information into an analogous sequence of sequential comparisons of sample information. The confocal topography detecting method according to claim 19, wherein the spectral image pattern is a digital discrete spectral image pattern, and the confocal topography detecting method further comprises a discrete spectrum for each digit. The image pattern is calculated with the spectral correction matrix to be converted into an analogous sequence of spectral image patterns. The confocal surface topography detecting method according to claim 20, wherein the specific position is a position of a surface, an inner surface or a bottom surface of the object, and determining the depth information of each specific position further comprises the following steps: Performing a normalized image matching operation by extracting at least one sub-spectral image pattern corresponding to the light position of the object from the continuous spectral image pattern, and comparing each of the sub-spectral image patterns and the plurality of analogs in the database The continuous ratio is calculated on the sample information to generate a plurality of cross-correlation values for the sample information of the continuous analog ratio; and the ratio of the ratios of the maximum values of the plurality of cross-correlation values to the sample information Depth is known as depth information corresponding to a particular location of the sub-spectral image pattern. The method for detecting a confocal surface topography according to claim 16, further comprising the step of performing a vertical scan for changing a distance between the object and the microscope objective. To obtain spectral image patterns corresponding to different vertical depths, each of the spectral image patterns corresponding to different depths has a light intensity. A method for detecting a confocal surface topography according to any one of claims 16 to 22, wherein the microscope objective is a dispersion objective or the microscope objective has a dispersion module for each broadband Modulating the light dispersion, each broadband modulated light forming a plurality of detected lights having different continuous depths of focus and projecting onto the object, each detected light corresponding to a wavelength, each broadband modulated light being specific from the surface of the object The positional reflection forms the object light.