TW202104836A - External reflection-type three dimensional surface profilometer - Google Patents

Abstract

An external reflection type three-dimensional shape measuring instrument includes a light source, an optical deflecting component, an image capturing module and an arithmetic processor. The light source is used to provide a light beam. The light deflecting element includes an inner portion and an outer reflecting surface, wherein the light beam is incident through the inner portion and is deflected to an object after passing through the outer reflecting surface, and then a light image corresponding to the surface topography of the object is generated. The light image is then reflected by the external reflecting surface. The image capturing module is configured to receive the light image to generate a to-be-tested image. The arithmetic processor performs an operation on the to-be-tested image to obtain information on the surface topography of the object.

Description

External reflection type three-dimensional shape measuring instrument

The invention relates to a three-dimensional shape measuring instrument, and in particular to an external reflection type three-dimensional shape measuring instrument.

At present, the measurement methods of surface topography are generally divided into contact measurement method and non-contact measurement method. Among them, since the contact measurement method uses the probe to contact the object to be measured, there is a risk that the probe may scratch the object to be measured. In addition, the measurement accuracy of the contact measurement method will be affected by the size and quality of the probe, so it is necessary to repeat the measurement several times to eliminate or reduce the impact of the size and quality of the probe on the accuracy of the measurement. When the range to be measured is larger, the required measurement time will increase significantly. Conjugate focus microscope is more common for non-contact measurement method. Although the resolution of conjugate focus microscope is high and the risk of scratches that may be caused by contact measurement method can be avoided, the measurement range of conjugate focus microscope is small. When the measurement area is large, the measurement time required will also increase substantially.

Therefore, there is still an urgent need for a method for measuring surface topography, which can avoid the problem that the contact measurement method may scratch the object to be measured and can shorten the time required for measurement.

The present invention relates to an external reflection type three-dimensional topography measuring instrument, which can measure the surface topography of the object to be measured in a non-contact method, so that it can avoid the problem that the contact measurement method may scratch the object to be measured, and can shorten The time required for the measurement.

According to one aspect of the present invention, an external reflection type three-dimensional shape measuring instrument is provided. The external reflection type three-dimensional shape measurement includes a light source, a light deflection element, an image capture module and an arithmetic processor. The light source is used to provide a light beam. The light deflection element includes an inner part and an outer reflecting surface. The light beam enters through the inner part and is deflected to an object to be measured after passing through the outer reflecting surface, and then generates a light and shadow corresponding to the surface topography of the object to be measured , The light and shadow are reflected by the external reflecting surface, and the light and shadow are imaged on the image capturing module through an imaging lens. The image capturing module is used for receiving light and shadow to generate an image to be measured. The arithmetic processor performs calculations on the image to be measured to obtain information on the surface topography of the object to be measured.

According to another aspect of the present invention, an external reflection type three-dimensional shape measuring instrument is provided. The external reflection type three-dimensional shape measurement includes a light source, a light deflection element, a light and shadow beam splitter, an image capture module and an arithmetic processor. The light source is used to provide a light beam. The light deflection element includes an inner part and an outer reflecting surface. The light beam enters through the inner part and is deflected to an object to be measured after passing through the outer reflecting surface, and then generates a light and shadow corresponding to the surface topography of the object to be measured . The light and shadow beam splitter divides the light and shadow reflected by the object to be measured into a first light and shadow and a second light and shadow, wherein the second light and shadow are reflected by the external reflecting surface. The image capture module includes a first image capturer and a second image capturer. The first image capturer is used to receive the first light and shadow to generate a reference image, and the second image capturer is used to receive the second image capture. Light and shadow to generate an image to be measured. The reference image and the image to be measured are respectively imaged on the first image capturer and the second image capturer by two imaging lenses with the same focal length. The calculation processor performs calculations on the reference image and the image to be measured to obtain the information of the surface topography of the object to be measured.

In order to have a better understanding of the above and other aspects of the present invention, the following specific examples are given in conjunction with the accompanying drawings to describe in detail as follows:

FIG. 1 is a schematic diagram of an external reflection type three-dimensional shape measuring instrument 100 according to an embodiment of the present invention.

Please refer to Figure 1, the external reflection type three-dimensional shape measuring instrument 100 includes a light source 110, a light guide element 120, a light deflection element 130, an imaging lens 150, an image capture module 160, and an arithmetic processor 170. The light source 110 is used to provide a light beam. In this embodiment, the light source 110 may be a red light emitting diode, which can not only reduce the cost but also reduce the size, but the present invention is not limited to this, and the light source 110 may also be light of other colors. The light guide assembly 120 includes a beam expander 122, a beam splitter 124, and a polarization beam splitter 126. The beam expander 122 can be used to expand the beam into a parallel beam. In this embodiment, the beam expander 122 may include a spatial filter 1221, a lens 1223, and an aperture 1225. The spatial filter 1221 may include an objective lens 1221a and a pinhole 1221b located between the objective lens 1221a and the lens 1223. The beam splitter 124 may be located between the beam expander 122 and the polarization beam splitter 126. When the light beam provided by the light source 110 passes through the objective lens 1221a, it will be focused to the pinhole 1221b placed on the focal point of the objective lens 1221a to filter out scattered or diffracted light, forming a noise-free point light source, and the point light source will be spherical wave The form of divergence, the parallel light with uniform light intensity is turned into by the lens 1223, and then the size of the light spot is adjusted through the aperture 1225, and the light is split by the beam splitter 124. In some embodiments, the photometer 124p can be used to measure the light intensity of the first light separated by the spectrophotometer 124 to calibrate the light source, which can avoid the influence of the unstable light source on the measurement.

The transmitted light passing through the light splitting beam 124 is split by the polarization beam splitting beam 126, and then enters the light deflection element 130. In one embodiment, the polarization beam splitter 126 can reflect and split the S-polarized light and incident the S-polarized light to the light deflection element 130. However, the present invention is not limited to this. General light (including S-polarized light and P-polarized light) Polarized light can also be incident on the light deflection element 130. The light deflection element 130 includes an inner portion 130i and an outer reflective surface 130a. The light beam is incident through the inner portion 130i and deflected to an object 140 to be measured after passing through the outer reflective surface 130a. In an embodiment, the incident angle formed between the light beam that passes through the outer reflective surface 130a and is deflected to the object 140 and the surface of the object 140 is 50° to 90°, but the present invention does not use this For limitation, the incident angle can be other suitable angles. In some embodiments, the light deflection element 130 may be a triangular ridge, and the light deflection element 130 further includes an _{incident surface 130b that forms an angle α 1} with the outer reflective surface 130a, and the light beam enters the interior from the incident surface 130b. The part 130i is deflected to the object to be measured 140 after passing through the outer reflecting surface 130a. In this embodiment, the light deflection element 130 may be a right-angle ridge, the external reflective surface 130a is a slope of a right-angle ridge, and the included angle α ₁ between the external reflective surface 130a and the incident surface 130b may be 30°, but The present invention is not limited to this, and the included angle α ₁ between the external reflection surface 130a and the incident surface 130b may be other suitable angles. In some embodiments, the light deflection element 130 may be a grating structure.

After the light beam passes through the external reflective surface 130a and is deflected to an object 140 to be measured, a light shadow corresponding to the surface topography of the object 140 is generated, and the light shadow is reflected by the external reflective surface 130a. The imaging lens 150 can image the light and shadow to the image capturing module 160. The image capturing module 160 can be used to receive light and shadow to generate an image to be measured. The arithmetic processor 170 performs calculations on the image to be measured to obtain information on the surface topography of the object 140 to be measured.

In this embodiment, the number of the lens 1223 and the imaging lens 150 is one respectively, but the present invention is not limited to this. The number of the lens 1223 and the imaging lens 150 may be multiple respectively, depending on requirements.

In one embodiment, the light and shadow reflected by the test object 140 are incident on the imaging lens 150 by a single reflection of the reflective surface 130 a outside the light deflection element 130.

In one embodiment, the light and shadow reflected by the object 140 is directly incident on the image capturing module 160 after being incident on the imaging lens 150. That is, no other element (such as a quadrilateral lens or an objective lens) may be disposed between the imaging lens 150 and the image capturing module 160.

In some embodiments, the image capturing module 160 may be a charge-coupled device (CCD). A charge-coupled device is an integrated circuit with neatly arranged capacitors. Each pixel can convert an optical signal into electrical energy, and then into digital information and output as an image. The arithmetic processor 170 may be, for example, a computer.

。由於反射率R與入射角度θ呈一線性關係(如第3圖所示)，故運算處理器170可藉由反射率R換算得知待測物140的高度(如第5~6圖及相關說明所示)。因此，運算處理器170將待測物140之待側影像及參考影像相除並經運算之後可得到待測物140的三維形貌圖(未繪示)以及二維形貌剖面圖(如第7圖所示)。In this embodiment, a flat mirror can be placed at the position of the test object 140 first, and a reference image is obtained by the image capturing module 160 receiving the image of the flat mirror, and at the same time, the light intensity when the image of the flat mirror is captured (for example, It is known by the spectrophotometric measurement of the spectrophotometer 124). After that, the plane mirror is removed and the object to be measured 140 is placed. The image of the object to be measured 140 can be received by the image capturing module 160 to obtain an image to be measured, and the current light intensity can also be recorded to complete the measurement. The calculation processor 170 can perform calculations on the reference image and the image to be measured to obtain information on the surface topography of the object to be measured 140. In short, let the spectral intensity of the reference image be I ₁ , and the light intensity of the image to be measured as I ₂ , the reflectance R=

. Since the reflectance R and the incident angle θ have a linear relationship (as shown in Fig. 3), the computing processor 170 can calculate the height of the object 140 by converting the reflectance R (as shown in Figs. 5-6 and related As shown in the description). Therefore, the computing processor 170 divides the to-be-side image and the reference image of the object 140 to be measured, and after calculation, a three-dimensional topographical image (not shown) and a two-dimensional cross-sectional image of the object 140 can be obtained (such as 7 shown).

Figure 2 shows a schematic diagram of an external reflection type three-dimensional profile measuring instrument 200 according to another embodiment of the present invention. The external reflection type three-dimensional profile measuring instrument 200 is similar to the external reflection type three-dimensional profile measuring instrument 100, with the difference The point lies in the design of the imaging lens assembly 250 and the image capturing module 260 and the addition of a light and shadow beam splitter 280, and other similarities or similarities will not be described in detail.

Please refer to Figure 2, the external reflection type three-dimensional shape measuring instrument 200, a light source 110, a light guide assembly 120, a light deflection element 230, a light and shadow beam splitter 280, an imaging lens assembly 250, and an image capture module 260 And an arithmetic processor 170. The light source 110 is used to provide a light beam. In this embodiment, the light source 110 may be a red light emitting diode, which can not only reduce the cost but also reduce the size, but the present invention is not limited to this, and the light source 110 may also be light of other colors. The light guide assembly 120 includes a beam expander 122, a beam splitter 124, and a polarization beam splitter 126. In this embodiment, the beam expander 122 may include a spatial filter 1221, a lens 1223, and an aperture 1225. The spatial filter 1221 may include an objective lens 1221a and a pinhole 1221b located between the objective lens 1221a and the lens 1223. The beam expander 122 is used to expand the beam into a parallel beam, the polarization beam splitter 126 performs beam splitting, and then the beam is incident on the light deflection element 230.

In this embodiment, the polarization beam splitter 126 can reflect and split the S-polarized light, and the S-polarized light is incident on the light deflection element 230. However, the present invention is not limited to this, and general light (including S-polarized light and P-polarized light) can also be incident on the light deflection element 230. The light deflection element 230 includes an inner portion 230i and an outer reflective surface 230a, wherein the light beam is incident through the inner portion 230i and is deflected to an object 140 to be measured after passing through the outer reflective surface 230a. In one embodiment, the incident angle formed between the light beam that passes through the outer reflecting surface 230a and is deflected to the object 140 and the surface of the object 140 is 50° to 90°, but the present invention does not use this For limitation, the incident angle can be other suitable angles. In some embodiments, the light deflection element 230 may be a triangular ridge, and the light deflection element 230 further includes an _{incident surface 230b that forms an angle α 2} with the outer reflecting surface 230a, and the light beam enters the interior from the incident surface 230b. The part 230i is deflected to the object to be measured 140 after passing through the outer reflective surface 230a. In this embodiment, the light deflection element 230 may be a right-angle ridge, the external reflection surface 230a is a slope of a right-angle ridge, and the included angle α ₂ between the external reflection surface 230a and the incident surface 230b may be 30°, but The present invention is not limited to this, and the included angle α ₂ between the external reflection surface 230a and the incident surface 230b may be other suitable angles. In some embodiments, the light deflection element 230 may be a grating structure.

。由於反射率R與入射角度θ呈一線性關係(如第3圖所示)，故運算處理器170可藉由反射率R換算得知待測物140的高度(如第5~6圖及相關說明所示)。因此，運算處理器170將待測物140之參考影像及待側影像相除並經運算之後可得到待測物140的三維形貌圖(未繪示)以及二維形貌剖面圖(如第8圖所示)。After the light beam passes through the outer reflective surface 230a and is deflected to an object 140 to be measured, a light shadow corresponding to the surface topography of the object 140 is generated. The light and shadow beam splitter 280 divides the light and shadow reflected by the test object 140 into a first light and shadow and a second light and shadow. The imaging lens assembly 250 includes a first imaging lens 252 and a second imaging lens 254. The image capture module 260 includes a first image capture 262 and a second image capture 264. The first imaging lens 252 can image the first light and shadow to the first image capturer 262. The second light and shadow are reflected to the second imaging lens 254 via the external reflective surface 230 a, and the second imaging lens 254 can image the second light and shadow to the second image capturer 264. The first image capturer 262 is used for receiving the first light and shadow to generate a reference image, and the second image capturer 264 is used for receiving the second light and shadow to generate a test image. The calculation processor 170 performs calculations on the reference image and the image to be measured to obtain information on the surface topography of the object to be measured 140. In short, let the spectral intensity of the reference image be I ₁ , and the light intensity of the image to be measured as I ₂ , the reflectance R=

. Since the reflectance R and the incident angle θ have a linear relationship (as shown in Fig. 3), the computing processor 170 can calculate the height of the object 140 by converting the reflectance R (as shown in Figs. 5-6 and related As shown in the description). Therefore, the arithmetic processor 170 divides the reference image and the side image of the object to be measured 140 and obtains the three-dimensional topography (not shown) and the two-dimensional cross-sectional view of the object 140 (such as the first 8 shown).

In this embodiment, the second light and shadow reflected by the test object 140 is incident on the second imaging lens 254 by a single reflection of the reflective surface 230 a outside the light deflection element 230.

In this embodiment, the first light and shadow reflected by the object 140 is directly incident on the first image capturer 262 after being incident on the first imaging lens 252. That is, no other element (such as a quadrilateral lens or an objective lens) may be disposed between the first imaging lens 252 and the first image capturer 262. After being incident on the second imaging lens 254, the second light and shadow reflected by the object 140 is directly incident on the second image capturer 264. That is, no other element (such as a quadrilateral lens or an objective lens) is provided between the second imaging lens 254 and the second image capturer 264.

In this embodiment, the number of the lens 1223, the first imaging lens 252, and the second imaging lens 254 is one, but the present invention is not limited to this. The lens 1223, the first imaging lens 252, and the second imaging lens The number of 254 can be multiple, depending on the needs.

In some embodiments, the first image capturer 262 and the second image capturer 264 may be charge coupled devices, respectively. The arithmetic processor 170 may be, for example, a computer.

FIG. 3 is a schematic diagram of the relationship between the light and shadow reflectance (R) and the incident angle (θ) of the object 140 of the external reflection type three-dimensional profile measuring instrument according to an embodiment of the present invention. Figure 3 exemplarily shows the relationship between the reflectivity of S-polarized light incident on the object under test 140 and the incident angle. However, the present invention is not limited to this, and general light (including S-polarized light and P-polarized light) The light) is incident on the object to be measured 140 for measurement.

The present invention uses an external reflection type three-dimensional shape measuring instrument to measure the shape of the object to be measured, that is, the light and shadow reflected by the object 140 or the second light and shadow are reflected to the imaging lens 150 via the external reflection surface 130a or 230a. Or the second imaging lens 254 instead of reflecting on the inner part 130i or 230i of the light deflection element 130 or 230. Compared with the internal reflection type three-dimensional shape measuring instrument, because the external reflection type measurement method can have a larger angle and height measurement range, and the area of the object to be measured is also larger, it is more suitable for Large-area three-dimensional surface topography measurement, as shown in Figure 4.

Figure 4 is a graph showing the relationship between the incident angle θ and the reflectivity R when light is externally reflected and internally reflected by the light deflection element. The dashed line segment represents the curve of internal reflection, and the solid line segment represents external reflection. Curve.

Please refer to Figure 4, TE represents the curve of S-polarized light, and TM represents the curve of P-polarized light. When the light is internally reflected by the light deflection element, the usable maximum incident angle θ _C can be 41.81°; when the light is externally reflected by the light deflection element, the usable maximum incident angle θ _C can be 90°, It can be seen that the usable incident angle range of external reflection is relatively large, and the measurable angle is relatively large. When the P-polarized light deflected by the reflection element, the incident angle θ _'P is 33.69 ° when the reflectivity of 0 (also called Brewster's angle). When P-polarized light is externally reflected by the light deflection element, _{if the incident angle θ P} is 56.31°, the reflectance is 0 (also called Brewster angle), that is, when the incident angle θ _P is 56.31° , That is, P-polarized light cannot be used. Therefore, the use of polarization beam splitter 126 to separate S-polarized light can avoid the problem that a specific incident angle cannot be used.

FIG. 5 is a schematic diagram of an imaging system of an external reflection type three-dimensional profile measuring instrument according to an embodiment of the present invention.

式1-1Referring to FIG. 5, the imaging systems of the reflective three-dimensional topography measuring instruments 100 and 200 of the present invention use imaging lenses 350 (for example, imaging lens 150, first imaging lens 252, or second imaging lens 254) to form images. The imaging path starts from the reflected light and shadow of the test object 140, reflects on the external reflective surface (such as 130a and 230a), passes through the imaging lens 350 (such as the imaging lens 150, the first imaging lens 252 or the second imaging lens 254) to focus, and finally imaging In the image capturing module 360 (for example, the image capturing modules 160 and 260). As shown in Figure 5, let X _S be the height of the object center, X _S 'be the height of the edge of the object, X ₁ be the height of the image center, and X ₁ ' be the height of the image edge, the horizontal magnification can be defined by Know the following formula 1-1:

Formula 1-1

式1-2The imaging lens 350 so that the center point is O, by similar triangles ΔX _S 'X _S O and ΔX _1' X ₁ O may be obtained by the following formula 1-2:

Formula 1-2

式1-3Substituting formula 1-2 back to formula 1-1 can obtain the magnification shown in formula 1-3:

Formula 1-3

FIG. 6 is a schematic diagram of the measuring principle of the object to be measured of the external reflection type three-dimensional shape measuring instrument according to an embodiment of the present invention.

式2-1Please refer to Figure 6, when the incident light L is perpendicular to the object 140, the surface of the object 140 may be uneven, so the protrusions will have a slight inclination angle, so that the reflected light will be tilted by 2 times. Lean away. Among them, Δα represents the inclination angle of the test object 140, Δh represents the height of the test object 140, and Δx represents the size of the distance between the test object 140 and each pixel of the image capturing module 160 or 260. From Figure 6, the relational expressions of Δα, Δh and Δx as shown in the following formula 2-1 can be obtained:

Formula 2-1

式2-2From equation 2-1, it can be derived to the following equation 2-2:

Formula 2-2

式2-3Since the incident light L will leave the object under test 140 at an inclination angle Δα twice and be incident on the external reflecting surface 130a or 230a of the light deflection element 130 or 230, the incident angle of the external reflecting surface 130a or 230a is Δθ=2Δα, then Get the following formula 2-3:

Formula 2-3

)

式2-3If the size ΔX of the interval between each pixel of the image capturing module 160 or 260 is divided by the magnification M _T (as shown in equations 1-3), the height Δh of the object to be measured 140 can be obtained, as shown in the following equation 2 -4 shows: Δh=tan(

)

Formula 2-3

In order to verify the effect of the present invention, the measurement results of the reflective three-dimensional profile measuring instruments 100 and 200 other than one embodiment of the present invention are the same as those of the existing laser scanning confocal microscope (Laser Scanning Confocal Microscope) and film thickness. The measurement results of the profile measuring instrument (alpha-step) are compared. The external reflection type three-dimensional shape measuring instrument 100 performs measurement in a single image analysis method. The external reflection type three-dimensional shape measuring instrument 200 performs measurement by means of dual image analysis.

FIG. 7A shows a cross-sectional view of the two-dimensional topography of the object 140 measured by the reflective three-dimensional topography measuring instrument 100 according to an embodiment of the present invention, where the abscissa represents the x-axis direction of the object The morphology change (unit is micrometers), the ordinate represents the morphology change (unit is micrometers) of the test object in the z-axis direction (that is, the height h). Figure 7B shows the result of 10 measurements on point A in Figure 7A.

Referring to FIGS. 7A and 7B, the surface topography of the object 140 may include the highest points of the raised wave crests: point A and point B. If point A is measured 10 times and compared with the measurement result of a laser scanning conjugate focus microscope, the maximum error value is 0.97% and the standard deviation is 0.07 microns.

Figure 8A shows a cross-sectional view of the two-dimensional shape of the object 140 measured by the reflective three-dimensional shape measuring instrument 200 according to another embodiment of the present invention, where the abscissa represents the x-axis direction of the object to be measured The topography change (unit is micrometers), and the ordinate represents the topography change (unit: micrometers) of the test object in the z-axis direction (that is, the height h). Figure 8B shows the result of 10 measurements on point A in Figure 8A.

Please refer to FIGS. 8A and 8B. The surface topography of the object 140 may include the highest points of the raised wave crests: point A and point B. If point A is measured 10 times and compared with a laser scanning conjugate focus microscope, the maximum error value is 1.05% and the standard deviation is 0.06 microns.

The above-mentioned measurement results of the external reflection type three-dimensional shape measuring instrument 100 (Example 1) and the external reflection type three-dimensional shape measuring instrument 200 (Example 2) of the present invention are compared with the laser scanning conjugate focus microscope (Comparative Example 1). ) And the measurement results of the film thickness profile measuring instrument (Comparative Example 2), as shown in Table 1 below.

Table I (Unit: μm) Comparative example 1 Comparative example 2 Example 1 Example 2 Height of point A 12.876 12.93 12.9 13.04 Height of point B 12.905 12.95 12.95 12.89 Half-height 26.767 26.5 15 26

From the results in Table 1, it can be seen that the minimum error of the external reflection type three-dimensional shape measuring instrument 100 (Example 1) of the present invention is 0.18%, and the minimum error of the external reflection type three-dimensional shape measuring instrument 200 (Example 2) is 0.12. %. It can be seen that the measurement error of the reflective three-dimensional topography measuring instruments 100 and 200 outside the present invention is small, and the surface topography of the object 140 to be measured can be accurately measured.

The following table 2 further compares the laser scanning conjugate focus microscope (Comparative Example 1), the film thickness profile measuring instrument (Comparative Example 2) and the reflective three-dimensional profile measuring instrument 200 (Example 2) outside the present invention. Differences in range, measurement time, and instrument cost.

Table II Comparative example 1 Comparative example 2 Example 2 Measuring range 272×204(μm ² ) 2 (mm) 4.83×3.63 (mm ² ) Measuring time 2 (min) 2 (min) 2(min) Instrument cost Over a million Over a million Less than 100,000

From the results in Table 2, it can be seen that although the resolution of the laser scanning conjugate focus microscope (Comparative Example 1) is high, the measurement time is longer when measuring a larger range of the object to be measured, and the laser scanning type The equipment of the yoke microscope is quite expensive. In contrast, the external reflection type three-dimensional profile measuring instrument according to an embodiment of the present invention not only has a measurement accuracy that is quite close to that of a conjugate focus microscope, but also can measure a larger range of samples in a relatively short time. The cost of the external reflection type three-dimensional topography measuring instrument is relatively low (for example, less than 100,000 yuan), which can greatly reduce the time and cost of measuring the surface topography.

To sum up, although the present invention has been disclosed as above by embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to those defined by the attached patent scope.

100, 200: External reflection type three-dimensional shape measuring instrument 110: Light source 120: Light guide component 122: Beam expander 124: Spectrophotometer 124p: Photometer 126: Polarization spectrophotometer 130, 230: Light deflection element 130a , 230a: external reflection surface 130b, 230b: incident surface 130i, 230i: internal part 150, 350: imaging lens 160, 260, 360: image capture module 170: arithmetic processor 250: imaging lens assembly 252: first imaging Lens 254: second imaging lens 280: light and shadow beam splitter 1221: filter 1221a: objective lens 1221b: pinhole 1223: lens 1225: aperture O: center point α ₁ , α ₂ : included angle

FIG. 1 is a schematic diagram of an external reflection type three-dimensional shape measuring instrument according to an embodiment of the present invention. FIG. 2 is a schematic diagram of an external reflection type three-dimensional shape measuring instrument according to another embodiment of the present invention. FIG. 3 is a schematic diagram of the relationship between the light and shadow reflectance of the object to be measured and the incident angle of the external reflection type three-dimensional profile measuring instrument according to an embodiment of the present invention. Fig. 4 is a graph showing the relationship between the incident angle and the reflectivity when light is externally reflected and internally reflected by the light deflection element. FIG. 5 is a schematic diagram of an imaging system of an external reflection type three-dimensional profile measuring instrument according to an embodiment of the present invention. FIG. 6 is a schematic diagram of the measuring principle of the object to be measured of the external reflection type three-dimensional shape measuring instrument according to an embodiment of the present invention. FIG. 7A is a cross-sectional view of the two-dimensional shape of the object to be measured measured by the reflective three-dimensional shape measuring instrument according to an embodiment of the present invention. Figure 7B shows the result of 10 measurements on point A in Figure 7A. FIG. 8A shows a cross-sectional view of the two-dimensional topography of the object to be measured measured by the reflective three-dimensional topography measuring instrument according to another embodiment of the present invention. Figure 8B shows the result of 10 measurements on point A in Figure 8A.

100: External reflection type three-dimensional shape measuring instrument

110: light source

120: Light guide component

122: beam expander

124: Spectroscopy

124p: photometer

126: Polarization Spectroscopy

130: light deflection element

140: DUT

130a: External reflective surface

130b: incident surface

130i: internal part

150: imaging lens

160: Image capture module

170: arithmetic processor

1221: filter

1221a: Objective

1221b: pinhole

1223: lens

1225: aperture

α ₁ : included angle

Claims (15)

An external reflection type three-dimensional shape measuring instrument, including: A light source for providing a light beam; A light deflection element includes an inner part and an outer reflecting surface, wherein the light beam is incident through the inner part and deflects to an object to be measured after passing through the outer reflecting surface, and then generates a light beam corresponding to the object to be measured A light and shadow of the surface topography, the light and shadow are then reflected by the external reflecting surface; An image capture module for receiving the light and shadow to generate an image to be tested; and An arithmetic processor performs calculations on the image to be measured to obtain information on the surface topography of the object to be measured. As described in item 1 of the scope of patent application, the external reflection type three-dimensional profile measuring instrument, wherein the light deflection element is a triangular horn, and the light deflection element also includes an incident angle formed at an angle with the external reflection surface. The light beam enters the inner part from the incident surface, and is deflected to the object to be measured after passing through the outer reflecting surface. For example, the external reflection type three-dimensional shape measuring instrument described in item 2 of the scope of patent application, wherein the light deflection element is a right-angle ridge, the external reflection surface is the slope of the right-angle ridge, and the included angle is 30°. As described in item 1 of the scope of patent application, the external reflection type three-dimensional shape measuring instrument further includes an imaging lens which can image the light and shadow to the image capturing module. As described in item 1 of the scope of the patent application, the external reflection type three-dimensional shape measuring instrument further includes a light guide component including a beam expander and a polarization beam splitter, and the beam expander is used for the The light beam is expanded into a parallel light beam, and the polarized light splitting beam splits the light, and then enters the light deflection element. As described in item 4 of the scope of patent application, the light and shadow reflected by the test object is incident on the light and shadow by a single reflection of the external reflecting surface of the light deflection element Imaging lens. As described in item 4 of the scope of patent application, the light and shadow reflected by the object to be measured are directly incident on the image capturing module after being incident on the imaging lens. As described in item 1 of the scope of patent application, the external reflection type three-dimensional shape measuring instrument, wherein the light deflection element is a grating structure. An external reflection type three-dimensional shape measuring instrument, including: A light source for providing a light beam; A light deflection element includes an inner part and an outer reflecting surface, wherein the light beam is incident through the inner part and deflects to an object to be measured after passing through the outer reflecting surface, and then generates a light beam corresponding to the object to be measured A light and shadow of surface topography; A light and shadow spectroscope for dividing the light and shadow reflected by the object to be measured into a first light and shadow and a second light and shadow, wherein the second light and shadow are reflected by the external reflecting surface; An image capture module includes a first image capturer and a second image capturer, wherein the first image capturer is used to receive the first light and shadow to generate a reference image, and the second image captures The device is used for receiving the second light and shadow to generate an image to be measured; An arithmetic processor performs operations on the image to be measured and the reference image to obtain information on the surface topography of the object to be measured. As described in item 9 of the scope of patent application, the external reflection type three-dimensional shape measuring instrument, wherein the light deflection element is a triangular prism, and also includes an incident surface that forms an angle with the external reflection surface, and the light beam is It enters the inner part from the incident surface, and is deflected to the object to be measured after passing through the outer reflecting surface. For example, the external reflection type three-dimensional shape measuring instrument described in item 10 of the scope of patent application, wherein the light deflection element is a right-angle ridge, the external reflection surface is the slope of the right-angle ridge, and the included angle is 30°. As described in item 9 of the scope of patent application, the external reflection type three-dimensional shape measuring instrument further includes a first imaging lens and a second imaging lens, and the first imaging lens can image the first light and shadow to the first image An extractor, the second imaging lens can image the second light and shadow to the second image extractor. As described in item 9 of the scope of the patent application, the external reflection type three-dimensional profile measuring instrument further includes a light guide component including a beam expander and a polarization beam splitter, and the beam expander is used for the The light beam is expanded into a parallel light beam, and the polarized light splitting beam splits the light, and then enters the light deflection element. As described in item 12 of the scope of patent application, the second light and shadow reflected by the object to be measured is reflected by a single reflection of the external reflecting surface of the light deflection element, and incident To the second imaging lens. As described in item 12 of the scope of patent application, the second light and shadow reflected by the object to be measured is directly incident on the second image capture after incident on the second imaging lens Device.

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