CN112067551A - Crystal grain adjacent surface complete aplanatic confocal imaging detection device and method based on Michelson-like interferometer structure - Google Patents
Crystal grain adjacent surface complete aplanatic confocal imaging detection device and method based on Michelson-like interferometer structure Download PDFInfo
- Publication number
- CN112067551A CN112067551A CN202010753504.6A CN202010753504A CN112067551A CN 112067551 A CN112067551 A CN 112067551A CN 202010753504 A CN202010753504 A CN 202010753504A CN 112067551 A CN112067551 A CN 112067551A
- Authority
- CN
- China
- Prior art keywords
- semi
- angle
- prism
- crystal grain
- semiconductor crystal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8806—Specially adapted optical and illumination features
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
- G01N21/9501—Semiconductor wafers
- G01N21/9505—Wafer internal defects, e.g. microcracks
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8806—Specially adapted optical and illumination features
- G01N2021/8841—Illumination and detection on two sides of object
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention provides a complete aplanatic confocal imaging detection device and a complete aplanatic confocal imaging detection method for crystal grain adjacent surfaces based on a Michelson-like interferometer structure, which comprises a light source, a camera, a telecentric imaging lens, a semi-transparent and semi-reflective parallel plate image combiner, a glass carrying turntable and a semiconductor crystal grain, wherein the semi-transparent and semi-reflective parallel plate image combiner is provided with a parallel plate compensator and a vertical plane right-angle turning prism which is positioned right above the semiconductor crystal grain at the same horizontal height, the semiconductor crystal grain is provided with a side right-angle turning prism at the same horizontal height and right below the semi-transparent and semi-reflective parallel plate image combiner, the device obtains space separation confocal imaging of adjacent surfaces under the condition of meeting the complete aplanatic confocal imaging of double-surface, can correct and compensate errors by adjusting the included angle between the parallel plate compensator and an optical axis, thereby realizing the simultaneous complete aplanatic imaging detection of the adjacent double surfaces, the structure is simple and compact, the assembly and debugging are easy, and the reliability is good.
Description
Technical Field
The invention relates to a device and a method for complete aplanatic confocal imaging detection of a crystal grain adjacent surface based on a similar Michelson interferometer structure.
Background
The complete aplanatic confocal imaging of the double-sided imaging detection light path of the crystal grain of the semiconductor refrigerating device is one of the main core technical problems for obtaining the simultaneous defect detection of double sides. Based on different detection devices and methods, the research of the prior semiconductor crystal grain adjacent double-sided simultaneous defect imaging detection technology has related patent applications:
as shown in fig. 1: invention patent application No. 202010171706.0X, patent application name: the optical detection device and the method well solve the problem of quasi-confocal imaging detection of the adjacent surfaces of the semiconductor crystal grains, but an optical path difference still exists between the adjacent double-sided imaging optical paths. To obtain simultaneous confocal imaging of adjacent surfaces, it is necessary to compensate for this small optical path difference by selecting a telecentric imaging lens with a sufficiently large depth of field. Therefore, a new approach for complete aplanatic confocal imaging detection of the adjacent surfaces of the crystal grains is necessary.
As shown in fig. 2: invention patent application No. 202010191734.8, patent application name: a novel crystal grain double-surface simultaneous aplanatic confocal imaging detection method based on time difference resolution provides a novel method for realizing complete aplanatic confocal imaging detection of adjacent surfaces of semiconductor crystal grains by using a single-group imaging system based on a time difference resolution imaging method.
As shown in fig. 3: the patent application name: the invention discloses a device and a method for crystal grain double-sided simultaneous aplanatic confocal imaging detection based on a two-color separation imaging method, and provides a novel method for simultaneously and completely aplanatic confocal imaging detection of adjacent surfaces of semiconductor crystal grains based on the two-color separation imaging method, wherein the patent application number of the invention is 202010203153.1.
As shown in fig. 4: the invention has the patent application number of 202010250856.X, and the patent application name is as follows: a device and a method for crystal grain double-face simultaneous complete aplanatic confocal imaging detection based on a polarization separation imaging method use a polarization beam splitter to obtain two beams of illumination beams with mutually vertical polarization directions to respectively illuminate two adjacent faces of a semiconductor crystal grain to be detected. Further provides a method based on polarized light separation imaging (polarization split imaging for short), and a device and a method for realizing simultaneous and complete aplanatic confocal imaging detection of adjacent surfaces of semiconductor crystal grains by using a polarization camera.
As shown in fig. 5: the invention has the patent application number of 202010296134.8, and the patent name is a device and a method for realizing the simultaneous aplanatism confocal detection of the double surfaces of crystal grains by using a polarization image splitting method, and provides a new method for realizing the simultaneous aplanatism confocal imaging detection of the adjacent surfaces of the semiconductor crystal grains by combining a polarization image splitting prism assembly and using a common CMOS or CCD camera based on the principle of polarized light separation imaging (polarization image splitting for short).
In the various detection devices, a polarization optical element or a polarization CMOS sensor is generally used, and the structure or the use is slightly complicated, the cost is high, and the error compensation capability of realizing the aplanatic and double-sided separation imaging detection at the same time is insufficient.
Disclosure of Invention
The invention improves the problems, namely the technical problems to be solved by the invention are that the completely aplanatic confocal imaging detection cost designed at present is higher and the error compensation capability is insufficient.
The specific embodiment of the invention is as follows: a full aplanatic confocal imaging detection device of crystal grain adjacent surfaces based on a Michelson-like interferometer structure comprises a CMOS or CCD camera, a telecentric imaging lens, a semi-transparent and semi-reflective parallel flat-plate image combiner, a glass carrying turntable and a semiconductor crystal grain arranged on the glass carrying turntable, which are sequentially arranged in the light path direction, a vertical right-angle image rotating prism, a parallel flat-plate compensator and a lateral right-angle image rotating prism are respectively and sequentially arranged on the light path between the semiconductor crystal grain and the semi-transparent and semi-reflective parallel flat-plate image combiner, the lateral right-angle image rotating prism and the vertical right-angle image rotating prism are respectively positioned at the right side part of the semiconductor crystal grain and right above a vertical plane, the vertical right-angle image rotating prism, the parallel flat-plate compensator and the semi-transparent and semi-reflective parallel flat-plate image combiner are positioned at the same horizontal height, the lateral right-angle image rotating prism and the semi-transparent and, meanwhile, a first right-angle surface of the side right-angle image-rotating prism is opposite to a first surface of the semi-transparent semi-reflective parallel flat-plate image combiner, a second right-angle surface of the side right-angle image-rotating prism is opposite to the side surface of the semiconductor crystal grain, and an inclined surface of the side right-angle image-rotating prism is obliquely arranged with an optical axis of the telecentric imaging lens;
two right-angle surfaces of the skyhook right-angle rotating image prism are respectively opposite to the skyhook of the semiconductor crystal grain and the second surface of the semi-transparent semi-reflective parallel flat-plate image combiner; a coaxial external illumination light source is arranged at the side of the semi-transparent semi-reflective parallel flat-plate image combiner departing from the second surface;
the light source is separated into a horizontal first light path and a longitudinal second light path by the semi-transmitting and semi-reflecting parallel flat-plate image combiner, and the first light path illuminates the skyward of the semiconductor crystal grain positioned on the glass loading turntable after passing through the first right-angle rotating image prism; the second light path illuminates the side surface of the semiconductor crystal grain to be tested after passing through a second right-angle image conversion prism;
imaging light beams of the semiconductor crystal grain skyward are incident on the parallel flat plate compensator through the first right-angle rotating image prism, are emitted in parallel through the parallel flat plate compensator to generate s displacement, and are reflected by the semi-transparent semi-reflective parallel flat plate image combiner to reach the reference output surface;
the imaging light beam on the side surface of the semiconductor crystal grain is reflected and turned by the second right-angle turning prism and then transmitted by the semi-transparent semi-reflective parallel flat plate image combiner to reach the reference output surface; the camera obtains images of the two faces independently.
Furthermore, the prism right-angle side length D of the top right-angle turning prism is the same as that of the side right-angle turning prism, the semiconductor crystal grain is positioned at the center of the glass carrying turntable, the center of the semi-transparent semi-reflective parallel flat-plate image combiner, the center of the reflection surface of the top right-angle turning prism and the side right-angle turning prism are connected with the center of the semiconductor crystal grain to form a square symmetrical light path structure with the side length of D/2+ D, and D is the center of the transparent glass carrying table width glass carrying turntable.
Furthermore, the distance between the center of the semi-transparent and semi-reflective parallel flat plate image combiner and the center of the side right-angle turning prism inclined plane is D/2+ D, the imaging optical path working distance WD of the side surface of the semiconductor crystal grain is = D/2+ D/2, the distance between the semi-transparent and semi-reflective parallel flat plate image combiner and the inclined plane of the skyhook right-angle turning prism is D/2+ D, and the imaging optical path working distance WD of the skyhook of the semiconductor crystal grain is = D/2+ D/2 on the same horizontal height.
Further, the size of the top right-angle relay prism is 15 × 15mm, and the size of the side right-angle relay prism is 15 × 15 mm.
Furthermore, the parallel plate compensator enables the semiconductor crystal grain top imaging light beam to generate a section of parallel displacement s, the size of the s depends on the thickness t of the parallel plate compensator, the thickness of the semi-transparent semi-reflective parallel plate image combiner is the glass refractive index n1 and the included angle theta 1 between the surface normal of the parallel plate compensator and the optical axis, and the material of the parallel plate compensator is K9 glass.
Further, the parallel plate compensator produces a double image separation s = 1.5mm, the focal length f =51.5mm, and WD =110 mm.
Furthermore, the thickness of the parallel plate compensator is 6.5mm, the included angle between the normal line and the optical axis is 12 degrees, and the parallel plate compensator is made of K9 glass.
Further, the coaxial external illumination light source is monochromatic light, or a quasi-monochromatic light source or white light with a certain spectral bandwidth.
The invention also comprises a complete aplanatic confocal imaging detection method of the crystal grain adjacent surface based on the Michelson-like interferometer structure, which comprises a CMOS or CCD camera, a telecentric imaging lens, a semi-transparent and semi-reflective parallel plate image combiner, a glass carrying turntable and a semiconductor crystal grain arranged on the glass carrying turntable, which are sequentially arranged in the light path direction, a vertical right-angle transfer prism, a parallel plate compensator and a lateral right-angle transfer prism are respectively and sequentially arranged on the light path between the semiconductor crystal grain and the semi-transparent and semi-reflective parallel plate image combiner, the lateral right-angle transfer prism and the vertical right-angle transfer prism are respectively positioned at the right side of the semiconductor crystal grain and right above the vertical, the vertical right-angle transfer prism, the parallel plate compensator and the semi-reflective parallel plate image combiner are positioned at the same horizontal height, the lateral right-angle transfer prism and the semi-transparent and semi-reflective parallel plate image combiner are positioned on the optical axis of the telecentric imaging lens, meanwhile, a first right-angle surface of the side right-angle image-rotating prism is opposite to a first surface of the semi-transparent semi-reflective parallel flat-plate image combiner, a second right-angle surface of the side right-angle image-rotating prism is opposite to the side surface of the semiconductor crystal grain, and an inclined surface of the side right-angle image-rotating prism is obliquely arranged with an optical axis of the telecentric imaging lens;
two right-angle surfaces of the skyhook right-angle rotating image prism are respectively opposite to the skyhook of the semiconductor crystal grain and the second surface of the semi-transparent semi-reflective parallel flat-plate image combiner; a coaxial external illumination light source is arranged at the side of the semi-transparent semi-reflective parallel flat-plate image combiner departing from the second surface;
during operation, the double-sided lighting light path:
the light source is separated into a horizontal first light path and a longitudinal second light path by the semi-transmitting and semi-reflecting parallel flat-plate image combiner, and the first light path illuminates the skyward of the semiconductor crystal grain positioned on the glass loading turntable after passing through the first right-angle rotating image prism; the second light path illuminates the side surface of the semiconductor crystal grain to be tested after passing through a second right-angle image conversion prism;
imaging detection light path: imaging light beams of the semiconductor crystal grain skyward are incident on the parallel flat plate compensator through the first right-angle rotating image prism, are emitted in parallel through the parallel flat plate compensator to generate s displacement, and are reflected by the semi-transparent semi-reflective parallel flat plate image combiner to reach the reference output surface;
the imaging light beam on the side surface of the semiconductor crystal grain is reflected and turned by the second right-angle turning prism and then transmitted to the reference output surface by the semi-transparent semi-reflective parallel flat plate image combiner; the camera obtains images of the two faces independently.
Compared with the prior art, the invention has the following beneficial effects: the application provides a novel device and a method for complete aplanatic confocal imaging detection of adjacent surfaces based on a Michelson-like interferometer structure, and spatial separation of adjacent double-sided imaging is realized by adopting double-glass parallel flat plates in adjacent double-sided imaging light paths. The novel device can obtain the simultaneous complete aplanatic confocal imaging detection of two adjacent surfaces of the semiconductor crystal grain, does not need to use a polarizing optical element and a polarizing CMOS sensor (camera), and effectively reduces the cost of the detection device.
1) The device is a double-parallel flat plate structure based on a similar Michelson interferometer structure, can realize the simultaneous complete aplanatic confocal imaging detection of two adjacent surfaces of a semiconductor crystal grain, and has simple structure and easy installation and adjustment;
2) the double-image separation distance s can be increased or decreased by adjusting the included angle between the parallel flat plate compensator and the optical axis in the imaging optical path of the device, and the influence on the optical path difference is small; the generated micro optical path difference can be compensated by the depth of field of the telecentric imaging lens.
3) The imaging optical path of the device can compensate and change the included angle between the parallel flat plate compensator 7 and the optical axis and the original tiny optical path difference of the mechanism by replacing the parallel flat plate compensator with different thicknesses, thereby realizing the simultaneous complete aplanatic confocal imaging detection of the two adjacent surfaces of the semiconductor crystal grains.
4) The device can also correct and compensate the tiny optical path difference caused by the angle manufacturing error and the assembly error of the semi-transmission and semi-reflection parallel flat plate image synthesizer or the right-angle rotating image prism by adjusting the included angle between the parallel flat plate compensator and the optical axis.
5) The device adopts a common parallel flat plate compensator, a parallel flat plate image combiner and a CMOS or CCD camera, does not need to use a polarization optical element and a polarization CMOS sensor (camera), and simultaneously has stronger functions of double-sided image splitting and manufacturing error compensation. The device can effectively reduce the cost of the detection device and improve the cost performance of the detection device.
6) The device for simultaneously imaging and detecting the adjacent double surfaces of the semiconductor crystal grains has the advantages of simple and compact structure, easy assembly and debugging and good reliability.
Drawings
FIGS. 1-5 illustrate conventional semiconductor die adjacent surface detection optics;
in the figure, 1 is a black-and-white camera, 2 is a telecentric imaging lens, 3 is a cubic beam splitter, 4 is a semiconductor crystal grain, 5 is a transparent glass object stage, 6 or 6a or 6b is a rotating image prism, 7 or 7a or 7b light source, and 8 and 9 are optical filters; 8a is a polarizing prism; 8b is a roof prism; and 8c is a trigger signal controller.
Fig. 6 is a detection device of the present patent application.
FIG. 7 is a schematic diagram of the rotation of the parallel plate compensator according to the present invention.
Fig. 8 is a design example of the present patent application.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
As shown in fig. 6-8, the confocal imaging detection device with complete aplanatic adjacent surfaces of crystal grains based on the michelson interferometer structure comprises a CMOS or CCD camera 1, a telecentric imaging lens 2, a semi-transparent and semi-reflective parallel plate image combiner 3, a glass carrying turntable 5 and a semiconductor crystal grain 6 arranged on the glass carrying turntable in sequence along the light path direction, a zenith right-angle rotating prism 4a, a parallel plate compensator 7 and a side right-angle rotating prism 4b are respectively arranged in sequence along the light path between the semiconductor crystal grain 6 and the semi-transparent and semi-reflective parallel plate image combiner, the side right-angle rotating prism and the zenith right-angle rotating prism are respectively positioned at the right side of the semiconductor crystal grain and right above the zenith, the zenith right-angle rotating prism, the parallel plate compensator 7 and the semi-transparent and semi-reflective parallel plate image combiner are positioned at the same horizontal height, the side right-angle rotating prism and the semi-transparent and semi-reflective parallel plate image combiner are positioned on the optical axis of the telecentric imaging, meanwhile, a first right-angle surface 401b of the side right-angle image-rotating prism is opposite to a first surface 301 of the semi-transparent semi-reflective parallel flat-plate image combiner, a second right-angle surface 402b of the side right-angle image-rotating prism is opposite to the side surface of the semiconductor crystal grain, and an inclined surface 403b of the side right-angle image-rotating prism is obliquely arranged with the optical axis of the telecentric imaging lens;
two right-angle surfaces of the skyhook right-angle rotating image prism are respectively opposite to the skyhook of the semiconductor crystal grain and the second surface 302 of the semi-transparent semi-reflective parallel flat-plate image combiner; the semi-transparent semi-reflective parallel flat-plate image combiner is provided with a coaxial external illumination light source 8 at the side departing from the second surface 302, namely the first surface 301;
the illumination light source 8 is separated into a horizontal first light path and a longitudinal second light path when passing through the semi-transparent semi-reflective parallel flat plate image combiner 3, and the first light path illuminates the skyward of the semiconductor crystal grain 6 of the glass loading turntable after passing through the parallel flat plate compensator 7 and the first right-angle rotating image prism; the second light path illuminates the side surface of the semiconductor crystal grain 6 to be tested after passing through a second right-angle image-rotating prism, two beams of illumination light respectively illuminate two adjacent surfaces of the semiconductor crystal grain 6, and enough illumination conditions are provided for simultaneous imaging of the two surfaces of the crystal grain;
imaging detection light path:
two adjacent surfaces of a semiconductor crystal grain 6 illuminated by a light source generate diffused light, an imaging light beam on the top surface of the semiconductor crystal grain is incident on a parallel flat plate compensator 7 with a certain thickness through a top right-angle rotating image prism 4a, is emitted in parallel through the parallel flat plate compensator 7 to generate s displacement, and is reflected by a semi-transmitting and semi-reflecting parallel flat plate image combiner 3 to reach a reference output surface; the imaging light beam on the side of the semiconductor crystal grain is reflected and turned by the side straight angle turning prism 4b, and then is transmitted by the semi-transparent semi-reflective parallel flat plate image combiner 3 to reach the reference output surface; the CMOS or CCD camera can respectively obtain independent images on two surfaces.
The illumination light source 8 for parallel light beam incidence on the right side of the semi-transparent semi-reflective parallel flat-plate image combiner 3 or the illumination light source 8 arranged at the front ends of the right-angle image-rotating prisms 4a and 4b on the top surface and the side surface can be monochromatic light, or can be quasi-monochromatic light source or white light with a certain spectral bandwidth.
The side length of the prism right-angle side of the top right-angle turning prism is the same as that of the side right-angle turning prism, the glass carrying turntable is circular, the semiconductor crystal grain is positioned in the center of the glass carrying turntable, the center of the semi-transparent semi-reflective parallel flat plate image combiner, the center of the reflection surface of the top right-angle turning prism and the side right-angle turning prism are connected with the center of the semiconductor crystal grain to form a square symmetrical light path structure with the side length of D/2+ D, and D is the center of the transparent glass carrying table width glass carrying turntable.
The distance between the center of the semi-transmissive and semi-reflective parallel flat plate image combiner and the center of the inclined plane of the side right-angle turning prism is D/2+ D, the working distance WD of an imaging light path on the side surface of the semiconductor crystal grain is = D/2+ D/2, the semi-transmissive and semi-reflective parallel flat plate image combiner and the inclined plane of the skyhook right-angle turning prism are on the same horizontal height, the distance D/2+ D is between the semi-transmissive and semi-reflective parallel flat plate image combiner and the inclined plane of the skyhook right-angle turning prism.
The parallel plate compensator 7 makes the semiconductor crystal grain 6 plane imaging light beam generate a parallel displacement s, the size of s depends on the thickness t of the parallel plate compensator 7, the thickness of the semi-transparent semi-reflective parallel plate image combiner 3 is the glass refractive index n1 and the included angle theta 1 between the normal line of the parallel plate compensator 7 surface and the optical axis.
And respectively obtaining complete aplanatic confocal imaging detection of the separation of the top surface and the side surface of the semiconductor crystal grain by using a common CMOS or CCD camera.
In this embodiment, as shown in fig. 7 and 8, the present invention provides a design embodiment of a front prism image rotating subsystem of a confocal imaging detection apparatus with completely aplanatic simultaneous adjacent surfaces of semiconductor dies.
1) In this embodiment, the length and width of the rectangular relay prism for the top surface of the semiconductor crystal grain is 15 × 15mm, the length and width of the rectangular relay prism for the side surface of the semiconductor crystal grain is 15 × 15mm, and the width of the transparent glass stage is 45 mm.
2) The semi-transmitting and semi-reflecting parallel flat-plate image combiner 3 center, the reflection surface centers of the right-angle rotating image prisms 4a and 4b and the semiconductor crystal grain center are connected to form a square symmetrical optical path structure with the side length of D/2+ D =37.5 mm.
3) The semi-transparent semi-reflective parallel flat plate image combiner 3 has the side length of 15mm and the thickness of 6mm, and is parallel to the hypotenuse of the skyhook right-angle relay prism and the side right-angle relay prism.
4) The side imaging optical path working distance WD = D/2+ D/2=30mm, and the top imaging optical path working distance WD = D/2+ D/2=30 mm.
As shown in fig. 7, the thickness of the parallel plate compensator 7 is h, the included angle between the normal line of the parallel plate compensator and the optical axis of the incident light is θ, and the included angle between the normal line of the parallel plate compensator and the optical axis of the emergent light is θ'; theta 1 is an included angle between the normal of the parallel flat plate compensator, the normal of the semi-transparent and semi-inverse parallel flat plate image combiner and an incident light axis, and is an initial state of the Michelson-like interferometer structure when the angle is 45 degrees, and theta 1' is an included angle between the normal of the parallel flat plate compensator, the normal of the semi-transparent and semi-inverse parallel flat plate image combiner and an emergent light axis; theta 2 is an included angle between a normal line of the parallel flat plate compensator in the device after rotation and an optical axis of incident light, and is a state of a Michelson interferometer-like structure with a slight change, and theta 2' is an included angle between the normal line of the parallel flat plate compensator in the device after rotation and an optical axis of emergent light.
When the angle between the parallel plate compensator 7 and the optical axis is 45 °, the absolute values of the imaging separation distance and the optical path difference are both 0, and when the deflection angle deviates from 45 °, the absolute values of the imaging separation distance and the optical path difference are larger. If the imaging separation distance is greater than 1.5mm, the angle of incidence is approximately <14 ° or >64 °; it can be known from observation that when the deflection angle of the parallel flat plate compensator 7 is deflected toward a direction smaller than 45 °, the absolute value of the optical path difference is changed more slowly than when the deflection angle is deflected toward a direction having an incident angle larger than 45 °, so that the scheme of selecting the deflection angle of the parallel flat plate compensator 7 smaller than 14 ° is reasonable, and the optical path difference is-0.65 mm at this time. The system can meet the requirement of double-sided imaging separation, can make the optical path difference small, and is suitable for an optical device for double-sided detection and simultaneous imaging.
The relation between the thickness of the parallel flat plate compensator and the optical path difference is as follows:
the incident angle of the parallel flat plate compensator 7 is 45 degrees as a design reference, the mechanism position aplanatism (the point O is coincident with the point O ') of the device is ensured, and the thickness t of the parallel flat plate compensator 7 is changed into t':
if only the thickness of the parallel plate compensator 7 is changed and the incident angle is not changed, the emergent angle is only related to the incident angle and the refractive index
θ1=θ2=45°，θ1’=θ2’，n1*sinθ1’=n*sinθ1（n=1）
The distance s between the center points of the two clear images:
s = t4-t2 = t’*sin(θ2-θ2’)/cosθ2’- t*sin(θ1-θ1’)/cosθ1’
=(t’-t)*sin(θ1-θ1’)/cosθ1’
the optical path difference can be expressed as:
thickness t optical path of original parallel flat plate compensator: Δ 1= IJ × n1+ JP + PO
The thickness t' of the existing parallel plate compensator is as follows: Δ 2= IJ '. n1+ J' O '+ O' P
Δ1-Δ2=IJ*n1+JP+PO -(IJ’*n1+J’O’+O’P)
Wherein x1= IJ, x2= IJ ', J' O '= t3-t1+ JP, O' P = OP = t4-t2
=x1*n1+(t4-t2)-x2*n1-(t3-t1)- (t4-t2)
=x1*n1 – x2*n1-(t3-t1)
=t*n1/cosθ1’–(t’-t)*cos(θ1-θ1’)/cosθ1’
The parameters t1, t2, t3 and t4 are shown in fig. 7 and can be calculated according to geometric relations.
As can be seen from the above, when the thickness of the parallel plate compensator 7 is changed, the variation of the image separation distance and the optical path difference is in a negative relationship. When the thickness of the parallel flat plate compensator 7 is changed to be larger, the image of the sky surface is separated to the left side more, and the optical path difference is linearly increased towards the negative direction; when the thickness of the parallel flat plate compensator 7 is changed to be smaller, the image of the sky surface is separated to the right side more, and the optical path difference is linearly increased to the positive direction.
To sum up, the conclusion that the separation distance is increased by changing the incident angle of the parallel plate compensator 7 is that when the parallel plate compensator 7 is deflected in the direction of less than 45 °, the thickness of the parallel plate compensator 7 can be reduced, and when the deflected angle is deflected in the direction of more than 45 °, the thickness of the parallel plate compensator 7 can be increased, thereby achieving the purpose of reducing the optical path difference and increasing the imaging separation distance.
To make the distance of the dual image separation large enough and the optical path difference as small as possible, the present embodiment provides the following three placement schemes of the parallel plate compensator satisfying the following conditions:
a) the thickness of the parallel flat plate compensator 7 is 6mm, the included angle between the normal line and the optical axis is 14 degrees, the parallel flat plate compensator is made of K9 glass, and the optical path difference of the double images of the scheme is 0.65 mm.
b) The thickness of the parallel flat plate compensator 7 is 6.2mm, the included angle between the normal line and the optical axis is 19 degrees, the parallel flat plate compensator is made of K9 glass, a turning prism of the skyhook mechanism needs to be adjusted downwards by 0.26mm, and the optical path difference of double images of the scheme is zero.
c) The thickness of the parallel flat plate compensator 7 is 6.5mm, the included angle between the normal line and the optical axis is 12 degrees, the parallel flat plate compensator is made of K9 glass, and the optical path difference of the double images in the scheme is zero.
5) The angle displacement error of the double images generated by the angle tolerance (less than or equal to 30 arc seconds) of the semi-transmitting and semi-reflecting parallel flat plate image combiner 3, the parallel flat plate compensator 7 and the right-angle relay prism is controlled within 2 arc minutes.
Any embodiment disclosed herein above is meant to disclose, unless otherwise indicated, all numerical ranges disclosed as being preferred, and any person skilled in the art would understand that: the preferred ranges are merely those values which are obvious or representative of the technical effect which can be achieved. Since the numerical values are too numerous to be exhaustive, some of the numerical values are disclosed in the present invention to illustrate the technical solutions of the present invention, and the above-mentioned numerical values should not be construed as limiting the scope of the present invention.
If the terms "first," "second," etc. are used herein to define parts, those skilled in the art will recognize that: the terms "first" and "second" are used merely to distinguish one element from another in a descriptive sense and are not intended to have a special meaning unless otherwise stated.
In addition, terms used in any technical solutions disclosed in the present invention to indicate positional relationships or shapes include approximate, similar or approximate states or shapes unless otherwise stated.
Any part provided by the invention can be assembled by a plurality of independent components or can be manufactured by an integral forming process.
Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the same; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.
Claims (9)
1. The device is characterized by comprising a CMOS or CCD camera, a telecentric imaging lens, a semi-transparent and semi-reflective parallel plate image combiner, a glass carrying turntable and a semiconductor crystal grain arranged on the glass carrying turntable which are sequentially arranged in the light path direction, wherein a top right-angle image transfer prism, a parallel plate compensator and a side right-angle image transfer prism are respectively and sequentially arranged on the light path between the semiconductor crystal grain and the semi-transparent and semi-reflective parallel plate image combiner, the side right-angle image transfer prism and the top right-angle image transfer prism are respectively positioned at the right side part of the semiconductor crystal grain and right above the top, the top right-angle image transfer prism, the parallel plate compensator and the semi-transparent and semi-reflective parallel plate image combiner are positioned at the same horizontal height, and the side right-angle image transfer prism and the semi-transparent and semi-reflective parallel plate image combiner are positioned on the optical axis of the telecentric imaging lens, meanwhile, a first right-angle surface of the side right-angle image-rotating prism is opposite to a first surface of the semi-transparent semi-reflective parallel flat-plate image combiner, a second right-angle surface of the side right-angle image-rotating prism is opposite to the side surface of the semiconductor crystal grain, and an inclined surface of the side right-angle image-rotating prism is obliquely arranged with an optical axis of the telecentric imaging lens;
two right-angle surfaces of the skyhook right-angle rotating image prism are respectively opposite to the skyhook of the semiconductor crystal grain and the second surface of the semi-transparent semi-reflective parallel flat-plate image combiner; a coaxial external illumination light source is arranged at the side of the semi-transparent semi-reflective parallel flat-plate image combiner departing from the second surface;
the light source is separated into a horizontal first light path and a longitudinal second light path by the semi-transmitting and semi-reflecting parallel flat-plate image combiner, and the first light path illuminates the skyward of the semiconductor crystal grain positioned on the glass loading turntable after passing through the first right-angle rotating image prism; the second light path illuminates the side surface of the semiconductor crystal grain to be tested after passing through a second right-angle image conversion prism;
imaging light beams of the semiconductor crystal grain skyward are incident on the parallel flat plate compensator through the first right-angle rotating image prism, are emitted in parallel through the parallel flat plate compensator to generate s displacement, and are reflected by the semi-transparent semi-reflective parallel flat plate image combiner to reach the reference output surface;
the imaging light beam on the side surface of the semiconductor crystal grain is reflected and turned by the second right-angle turning prism and then transmitted by the semi-transparent semi-reflective parallel flat plate image combiner to reach the reference output surface; the camera obtains images of the two faces independently.
2. The device for confocal imaging detection with complete aplanatism of crystal grain adjacent surfaces based on the michelson-like interferometer structure as claimed in claim 1, wherein the prism right-angle side length D of the zenith right-angle turning prism is the same as that of the side right-angle turning prism, the semiconductor crystal grain is located at the center of the glass carrying turntable, the semi-transparent and semi-reflective parallel flat plate image combiner center, the reflection surface center of the zenith right-angle turning prism, the side right-angle turning prism and the semiconductor crystal grain center are connected to form a square symmetrical optical path structure with the side length of D/2+ D, and D is the width of the glass carrying turntable.
3. The confocal imaging detection device with the complete aplanatism of the crystal grain adjacent surface based on the Michelson-like interferometer structure as claimed in claim 2, wherein the distance between the center of the semitransparent and semi-reflecting parallel flat plate image combiner and the center of the side right-angle turning prism inclined surface is D/2+ D, the imaging optical path working distance WD of the side surface of the semiconductor crystal grain is = D/2+ D/2, the distance between the semitransparent and semi-reflecting parallel flat plate image combiner and the top right-angle turning prism inclined surface is D/2+ D, and the imaging optical path working distance WD of the top surface of the semiconductor crystal grain is = D/2+ D/2.
4. The device according to claim 3, wherein the size of the right-angle relay prism is 15 x 15mm, and the size of the side-right-angle relay prism is 15 x 15 mm.
5. The confocal imaging detection apparatus with complete aplanatism of crystal grain adjacent surfaces based on the Michelson-like interferometer structure as claimed in claim 3, wherein the parallel plate compensator generates a section of parallel displacement s for the semiconductor crystal grain zenith imaging beam, the size of s is determined by the thickness h of the glass parallel plate compensator, the thickness of the semitransparent and semi-reflecting parallel plate integrator is glass refractive index n1 and the included angle θ 1 between the surface normal of the glass parallel plate compensator and the optical axis, and the material of the parallel plate compensator is K9 glass.
6. The device for confocal imaging detection based on complete aplanatism of crystal grain adjacent surfaces of the Michelson-like interferometer structure according to claim 4, wherein the parallel plate compensator generates double-image separation s = 1.5mm, the focal length f =51.5mm, and WD =110 mm.
7. The device for complete aplanatic confocal imaging and detecting the adjacent surfaces of the crystal grains based on the Michelson-like interferometer structure according to claim 4, wherein the thickness of the parallel plate compensator is 6.5mm, the included angle between the normal line and the optical axis is 12 degrees, and the material of the parallel plate compensator is K9 glass.
8. The device for completely aplanatic confocal imaging and detecting the adjacent surface of the crystal grain based on the Michelson-like interferometer structure according to claim 3, wherein the coaxial external illumination light source is monochromatic light, or a quasi-monochromatic light source or white light with a certain spectral bandwidth.
9. A full aplanatic confocal imaging detection method for a crystal grain adjacent surface based on a similar Michelson interferometer structure is characterized in that: the device is characterized by comprising a CMOS or CCD camera, a telecentric imaging lens, a semi-transparent and semi-reflective parallel plate image combiner, a glass carrying turntable and a semiconductor crystal grain arranged on the glass carrying turntable which are sequentially arranged in the light path direction, wherein a top right-angle image transfer prism, a parallel plate compensator and a side right-angle image transfer prism are respectively and sequentially arranged on the light path between the semiconductor crystal grain and the semi-transparent and semi-reflective parallel plate image combiner, the side right-angle image transfer prism and the top right-angle image transfer prism are respectively positioned at the right side part of the semiconductor crystal grain and right above the top, the top right-angle image transfer prism, the parallel plate compensator and the semi-transparent and semi-reflective parallel plate image combiner are positioned at the same horizontal height, and the side right-angle image transfer prism and the semi-transparent and semi-reflective parallel plate image combiner are positioned on the optical axis of the telecentric imaging lens, meanwhile, a first right-angle surface of the side right-angle image-rotating prism is opposite to a first surface of the semi-transparent semi-reflective parallel flat-plate image combiner, a second right-angle surface of the side right-angle image-rotating prism is opposite to the side surface of the semiconductor crystal grain, and an inclined surface of the side right-angle image-rotating prism is obliquely arranged with an optical axis of the telecentric imaging lens;
two right-angle surfaces of the skyhook right-angle rotating image prism are respectively opposite to the skyhook of the semiconductor crystal grain and the second surface of the semi-transparent semi-reflective parallel flat-plate image combiner; a coaxial external illumination light source is arranged at the side of the semi-transparent semi-reflective parallel flat-plate image combiner departing from the second surface;
during operation, the double-sided lighting light path:
the light source is separated into a horizontal first light path and a longitudinal second light path by the semi-transmitting and semi-reflecting parallel flat-plate image combiner, and the first light path illuminates the skyward of the semiconductor crystal grain positioned on the glass loading turntable after passing through the first right-angle rotating image prism; the second light path illuminates the side surface of the semiconductor crystal grain to be tested after passing through a second right-angle image conversion prism;
imaging detection light path: imaging light beams of the semiconductor crystal grain skyward are incident on the parallel flat plate compensator through the first right-angle rotating image prism, are emitted in parallel through the parallel flat plate compensator to generate s displacement, and are reflected by the semi-transparent semi-reflective parallel flat plate image combiner to reach the reference output surface;
the imaging light beam on the side surface of the semiconductor crystal grain is reflected and turned by the second right-angle turning prism and then transmitted to the reference output surface by the semi-transparent semi-reflective parallel flat plate image combiner; the camera obtains images of the two faces independently.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010753504.6A CN112067551A (en) | 2020-07-30 | 2020-07-30 | Crystal grain adjacent surface complete aplanatic confocal imaging detection device and method based on Michelson-like interferometer structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010753504.6A CN112067551A (en) | 2020-07-30 | 2020-07-30 | Crystal grain adjacent surface complete aplanatic confocal imaging detection device and method based on Michelson-like interferometer structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112067551A true CN112067551A (en) | 2020-12-11 |
Family
ID=73656372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010753504.6A Pending CN112067551A (en) | 2020-07-30 | 2020-07-30 | Crystal grain adjacent surface complete aplanatic confocal imaging detection device and method based on Michelson-like interferometer structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112067551A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114460001A (en) * | 2021-12-24 | 2022-05-10 | 合肥市商巨智能装备有限公司 | Optical system is examined on patrol limit of display panel |
-
2020
- 2020-07-30 CN CN202010753504.6A patent/CN112067551A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114460001A (en) * | 2021-12-24 | 2022-05-10 | 合肥市商巨智能装备有限公司 | Optical system is examined on patrol limit of display panel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3878107B2 (en) | Defect inspection method and apparatus | |
| CN110987964B (en) | Method for obtaining optical detection completely equal illumination of opposite two sides of semiconductor crystal grain | |
| CN109313008B (en) | Optical system and method for sample measurement | |
| CA2206212A1 (en) | Phase shifting diffraction interferometer | |
| US8547557B2 (en) | Apparatus for determining a height map of a surface through both interferometric and non-interferometric measurements | |
| CN111044524B (en) | Optical detection device and method for realizing equal optical path imaging of two opposite surfaces of semiconductor crystal grain | |
| CN111157535A (en) | Device and method for detecting crystal grain double-surface simultaneous aplanatic imaging and isoluminance illumination based on image combination optical element | |
| CN112067551A (en) | Crystal grain adjacent surface complete aplanatic confocal imaging detection device and method based on Michelson-like interferometer structure | |
| US20100027028A1 (en) | Oblique incidence interferometer | |
| US20100085637A1 (en) | Differential interference contrast microscope | |
| CN211856382U (en) | Detection device for crystal grain double-side simultaneous aplanatic imaging and isoluminance illumination | |
| CN212808013U (en) | Equal optical path imaging detection device for crystal grain adjacent surface of similar Michelson interferometer structure | |
| US20010040723A1 (en) | Differential interference optical system | |
| CN213337388U (en) | Novel device for simultaneously and completely aplanatic confocal imaging detection of two adjacent surfaces of semiconductor crystal grains | |
| CN111595861A (en) | Confocal imaging detection device and method for simultaneously and completely aplanatic crystal grain adjacent surfaces by using glass optical wedge for image splitting | |
| CN211856323U (en) | Device for simultaneous quasi-aplanatic confocal imaging detection of adjacent surfaces of semiconductor crystal grains | |
| CN211741108U (en) | Device for obtaining semiconductor crystal grain opposite two-side optical detection complete isoillumination illumination | |
| CN213091520U (en) | Crystal grain adjacent surface complete aplanatic confocal imaging detection device using optical wedge image splitting | |
| CN211426310U (en) | Detection device for realizing equal illumination and equal optical path imaging of two adjacent surfaces of object | |
| CN212646440U (en) | Complete aplanatic confocal imaging detection device based on parallel flat-plate image-splitting adjacent surfaces | |
| CN111366541A (en) | Device and method for realizing simultaneous aplanatic confocal detection of double surfaces of crystal grains by using polarization image splitting method | |
| CN111089840A (en) | Device and method for simultaneous quasi-aplanatic confocal imaging detection of adjacent surfaces of semiconductor crystal grains | |
| CN110806410A (en) | Optical device and method for simultaneously detecting top surface and side surface of semiconductor crystal grain | |
| JPH095018A (en) | Device for measuring moving quantity | |
| CN111487198A (en) | Parallel plate image-splitting-based confocal imaging detection device and method with complete aplanatism of adjacent surfaces at the same time |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |