CN116430570B - Light intensity correction, illumination, microscope imaging and silicon wafer defect detection device and method - Google Patents
Light intensity correction, illumination, microscope imaging and silicon wafer defect detection device and method Download PDFInfo
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- 238000012937 correction Methods 0.000 title claims abstract description 136
- 238000005286 illumination Methods 0.000 title claims abstract description 84
- 238000003384 imaging method Methods 0.000 title claims abstract description 57
- 238000000034 method Methods 0.000 title claims abstract description 45
- 230000007547 defect Effects 0.000 title claims abstract description 28
- 238000001514 detection method Methods 0.000 title claims abstract description 28
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 25
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 25
- 239000010703 silicon Substances 0.000 title claims abstract description 25
- 241000276498 Pollachius virens Species 0.000 claims abstract description 39
- 238000005457 optimization Methods 0.000 claims abstract description 11
- 230000003287 optical effect Effects 0.000 claims description 39
- 230000000903 blocking effect Effects 0.000 claims description 20
- 230000006870 function Effects 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 20
- 238000010586 diagram Methods 0.000 description 6
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- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
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Abstract
The invention provides a light intensity correction method, a light intensity correction device, a storage medium, an illumination system, a microscope imaging system and a silicon wafer defect detection device and method. The light intensity correction method comprises the following steps: taking first output light intensity distribution of an original light source about a field of view of a field diaphragm, a target light source size required by a Kohler illumination module and a target light source divergence angle as input variables, and taking first target illuminance distribution required by an output end of the Kohler illumination module as an optimization target to construct a light intensity correction model; acquiring the first output light intensity distribution, the target light source size, the target light source divergence angle and the first target illuminance distribution, and solving the light intensity correction model to determine the focal length, the distance and the obscuration field of view; and configuring the light intensity correction module according to the focal length, the distance and the obscuration field of view to correct the original light source to obtain a corrected light source that meets the first target illuminance distribution.
Description
Technical Field
The present invention relates to the field of illumination imaging, and more particularly, to a light intensity correction method, a light intensity correction device, a computer readable storage medium, an illumination system, a microscope imaging system, a silicon wafer defect detection device, and a silicon wafer defect detection method.
Background
Illumination uniformity greatly affects the dynamic range that a camera can use, as well as consistency in acquiring optical signals for different field of view regions. In the defect detection field, low illumination uniformity will reduce the dynamic range of the optical microscopy imaging detection system, while non-uniformity in the response intensity of the optical signals in the different field of view regions will increase the false detection rate of the optical microscopy imaging detection system. Therefore, the high-uniformity illumination and full-field consistent optical signal response has great significance for an optical microscopic imaging detection system.
Currently, optical microscopy imaging detection systems mainly implement bright field imaging of microscopy systems by means of kohler illumination (Kohler illumination). The kohler illumination can improve the illumination uniformity of the object plane by secondary imaging of the illumination light source such as a filament, but the uniformity of the kohler illumination is limited by the light intensity distribution of the light source, and the problem that the edge field illumination is less than the image plane illumination such as the center field illumination inevitably occurs in the imaging plane of the camera under the influence of the intrinsic illumination distribution characteristics such as the edge field obscuration, the large field aberration, the reflection loss of the lens high angle incidence and the like of the microscopic imaging system.
In order to overcome the above-mentioned drawbacks of the prior art, there is a need in the art for a light intensity correction technique for correcting the original light intensity distribution of an original light source at the front end of a kohler illumination system to obtain a corrected light source capable of producing a target illuminance distribution on a target plane.
Disclosure of Invention
The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
In order to overcome the above-mentioned drawbacks of the prior art, the present invention provides a light intensity correction method, a light intensity correction device, a computer readable storage medium, an illumination system, a microscope imaging system, a silicon wafer defect detection device, and a silicon wafer defect detection method, which can correct the original light intensity distribution of an original light source at the front end of a kohler illumination system to obtain a corrected light source that generates a target illuminance distribution on a target plane.
Specifically, the light intensity correction method provided according to the first aspect of the present invention includes the steps of: taking first output light intensity distribution of an original light source relative to a field of view of a field diaphragm, a target light source size required by a Kohler lighting module and a target light source divergence angle as input variables, taking first target illuminance distribution required by an output end of the Kohler lighting module as an optimization target, and taking a focal length of a light intensity correction module, a distance from the original light source to the light intensity correction module and a blocking field of the light intensity correction module to the original light source as optimization variables to construct a light intensity correction model, wherein the light intensity correction module is positioned between the original light source and the Kohler lighting module; acquiring the first output light intensity distribution, the target light source size, the target light source divergence angle and the first target illuminance distribution, and solving the light intensity correction model to determine the focal length, the distance and the obscuration field of view; and configuring the light intensity correction module according to the focal length, the distance and the obscuration field of view to correct the original light source to obtain a corrected light source that meets the first target illuminance distribution.
Further, in some embodiments of the invention, the first output light intensity distribution of the primary light source with respect to the field stop field of view is represented as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,for maximum light intensity at different areas of the field stop field of view,is the sine value of the included angle between the light and the optical axis,describing the direction of the light of maximum intensity at different areas of the field stop field,for the shape factor of the first output light intensity distribution,a blocking factor representing the primary light source, when viewed in fieldWhen it is blockedWhen viewing the field of viewWhen not covered by the mask。
Further, in some embodiments of the present invention, the first output light intensity distribution is selected from any one or a combination of gaussian distribution, lambertian distribution, exponential distribution.
Further, in some embodiments of the present invention, the light intensity correction module is comprised of an optical lens and a field of view blocking element. The deflection angle of the second output light intensity distribution of the corrected light source obtained through the light intensity correction module is expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,for the focal length of the optical lens,the incidence height of the maximum light intensity ray at different areas of the field diaphragm field is expressed as，Is the distance from the original light source to the optical lens.
Output illuminance distribution of the kohler illumination moduleEquivalent to the superposition of the light intensity distribution at different areas of the field stop field of view of the correction light sourceLight intensity normalized distribution:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,is the magnification of the optical lens, expressed as。
Further, in some embodiments of the present invention, the step of solving the light intensity correction model includes: and solving the light intensity correction model according to the equivalent light intensity normalized distribution and the first target illuminance distribution in a constraint range of the target light source size and the target light source divergence angle required by the Kohler illumination module so as to determine the focal length, the distance and the obscuration view field.
Further, in some embodiments of the invention, the first target illuminance distribution is characterized by illuminance uniformity, and the light intensity correction model is expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,representing the minimum value of the normalized distribution of the equivalent light intensity,representing the maximum value of the normalized distribution of the equivalent light intensity.
The step of solving the light intensity correction model further comprises: scanning the focal length of the optical lens by least square methodDistance and distanceThe view is as followsBlocking factor of field blocking elementTo determine the value of the functionAt least one set of optimized solutions meeting the first target illuminance distribution。
Further, in some embodiments of the invention, the first target illuminance distribution is represented as. The light intensity correction model is expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,representing the maximum value of the difference between the first target illuminance distribution and the equivalent light intensity normalized distribution.
The step of solving the light intensity correction model further comprises: scanning the focal length of the optical lens by least square methodDistance and distanceBlocking factor of the field of view blocking elementTo determine the value of the functionOptimal solution for obtaining minimum value thereof。
Further, in some embodiments of the present invention, an output of the kohler illumination module is connected to an input of the microimaging module. The step of obtaining the first target illuminance distribution includes: acquiring the image plane illumination distribution characteristic of the microscopic imaging module and the second target illumination distribution required by the output end of the microscopic imaging module; and inversely changing the second target illuminance distribution according to the image plane illuminance distribution characteristic to determine a first target illuminance distribution required by an output end of the kohler illumination module.
Further, a light intensity correction device provided according to a second aspect of the present invention includes a memory and a first processor. The memory has stored thereon computer instructions. The first processor is connected to the memory and is configured to execute computer instructions stored on the memory to implement the light intensity correction method according to any of the first aspects of the invention.
Further, a computer-readable storage medium according to a third aspect of the present invention is provided, on which computer instructions are stored. The computer instructions, when executed by a processor, implement a light intensity correction method as described in any one of the first aspects of the invention.
Further, an illumination system according to a fourth aspect of the present invention includes a primary light source, a light intensity correction module, and a kohler illumination module. The light intensity correction module is positioned between the original light source and the kohler illumination module. The focal length of the light intensity correction module and the distance from the light intensity correction module to the original light source. The obscuration field of view of the original light source by the light intensity correction module is determined by the light intensity correction method according to any of the first aspects of the invention.
Further, a microscope imaging system provided according to a fifth aspect of the present invention includes a spectroscopic plate, an illumination system, and a camera. The beam splitter is installed between the camera, the sample to be measured and the illumination system according to the fourth aspect of the present invention at a preset angle, and is used for introducing the illumination light outputted by the illumination system into the imaging light path of the camera for the sample to be measured. The illumination system outputs illumination light rays meeting second target illuminance distribution required by an output end of the microscopic imaging system to a sample to be detected through the first surface of the light splitting sheet and the microscopic objective lens. And the camera acquires the reflected light of the illumination light on the sample to be detected through the second surface of the light-splitting sheet and the microscope objective lens so as to generate an image of the sample to be detected.
Further, a device for detecting defects of a silicon wafer according to a sixth aspect of the present invention includes a microscope imaging system according to the fifth aspect of the present invention and a second processor. The second processor is connected with a camera of the microscope imaging system, and determines a detection result of the silicon wafer defect according to an image generated by the camera.
In addition, the method for detecting the defects of the silicon wafer provided by the seventh aspect of the invention comprises the following steps: generating an image of the sample to be measured via a microscope imaging system according to the fifth aspect of the invention; and analyzing the image to determine a silicon wafer defect detection result of the sample to be detected.
Drawings
The above features and advantages of the present invention will be better understood after reading the detailed description of embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily to scale and components having similar related features or characteristics may have the same or similar reference numerals.
Fig. 1 illustrates a schematic optical path diagram of a microscope imaging system provided in accordance with some embodiments of the invention.
Fig. 2 illustrates a flow chart of a light intensity correction method provided in accordance with some embodiments of the invention.
Fig. 3 illustrates a schematic diagram of an optical path of a light intensity correction module provided in accordance with some embodiments of the invention.
Fig. 4 illustrates a graph of a first output light intensity distribution of a primary light source with respect to a field stop field of view provided in accordance with some embodiments of the invention.
Fig. 5 illustrates a graph of a second light intensity distribution of a corrected light source with respect to a field stop field of view provided in accordance with some embodiments of the invention.
Fig. 6 illustrates a graph of normalized light intensity for an original light source versus a corrected light source, provided in accordance with some embodiments of the invention.
Fig. 7 illustrates a schematic diagram of an optical path of a light intensity correction module provided in accordance with some embodiments of the invention.
Fig. 8 illustrates a graph of normalized light intensity for an original light source versus a corrected light source, provided in accordance with some embodiments of the invention.
Fig. 9 illustrates a graph comparing camera responses as a function of camera field of view provided in accordance with some embodiments of the invention.
Detailed Description
Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present specification, by describing the embodiments of the present invention with specific examples. While the description of the invention will be presented in connection with a preferred embodiment, it is not intended to limit the inventive features to that embodiment. Rather, the purpose of the invention described in connection with the embodiments is to cover other alternatives or modifications, which may be extended by the claims based on the invention. The following description contains many specific details for the purpose of providing a thorough understanding of the present invention. The invention may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the invention.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" as used in the following description should be understood as referring to the orientation depicted in this paragraph and the associated drawings. This relative terminology is for convenience only and is not intended to be limiting of the invention as it is described in terms of the apparatus being manufactured or operated in a particular orientation.
It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, regions, layers and/or sections, these elements, regions, layers and/or sections should not be limited by these terms and these terms are merely used to distinguish between different elements, regions, layers and/or sections. Accordingly, a first component, region, layer, and/or section discussed below could be termed a second component, region, layer, and/or section without departing from some embodiments of the present invention.
As described above, although the conventional kohler illumination can improve the illumination uniformity of the object plane by the secondary imaging of the illumination light source such as the filament, the uniformity of the kohler illumination is limited by the light intensity distribution of the light source itself, and the problem of uneven image plane illuminance such as smaller edge field illuminance than central field illuminance is inevitably generated in the imaging plane of the camera under the influence of inherent illuminance distribution characteristics such as the edge field obscuration of the microscopic imaging system itself, large field aberration, reflection loss of lens high angle incidence, and the like.
In order to overcome the above-mentioned drawbacks of the prior art, the present invention provides a light intensity correction method, a light intensity correction device, a computer readable storage medium, an illumination system, a microscope imaging system, a silicon wafer defect detection device, and a silicon wafer defect detection method, which can correct the original light intensity distribution of an original light source at the front end of a kohler illumination system to obtain a corrected light source that generates a target illuminance distribution on a target plane.
In some non-limiting embodiments, the above-described light intensity correction method provided by the first aspect of the present invention may be implemented based on the above-described microscope imaging system provided by the fifth aspect of the present invention. Referring specifically to fig. 1, fig. 1 illustrates a schematic optical path diagram of a microscope imaging system provided according to some embodiments of the present invention.
As shown in fig. 1, in some embodiments of the present invention, a spectroscopic patch 11, a camera 20, and the above-described illumination system provided by the third aspect of the present invention may be provided in a microscope imaging system.
Further, the illumination system is provided with an original light source 31, a light intensity correction module 32 and a kohler illumination module 33. The light intensity correction module 32 is located between the original light source 31 and the kohler illumination module 33, and has an optical lens focal lengthDistance from the original light source 31And its obscuration field of view of the original light source 31The above-mentioned light intensity correction method according to the first aspect of the present invention is implemented to determine, so that a correction light source 31' is formed at the input end of the kohler illumination module 33, and then an illumination light beam satisfying a second target illuminance distribution required by the output end of the microscopic imaging system is output to the sample 40 to be measured through the first surface of the beam splitter 11 and the microscope objective 13.
The light splitting plate 11 is installed between the camera 20, the sample 40 to be measured and the illumination system at a preset angle (for example, 45 °), and is used for introducing the illumination light outputted by the illumination system into the imaging light path of the sample 40 to be measured by the camera 20 so as to uniformly illuminate the sample 40 to be measured.
The camera 20 obtains the reflected light of the illumination light on the sample 40 to be detected through the barrel lens 12, the second surface of the beam splitter 11 and the micro objective lens 13, so as to generate a detection image of the sample 40 to be detected.
Furthermore, the microscope imaging system may further be configured with the light intensity correction device (not shown) provided in the second aspect of the present invention, and the memory and the first processor are configured thereon. The memory includes, but is not limited to, the above-described computer-readable storage medium provided by the third aspect of the present invention, having stored thereon computer instructions. The first processor is coupled to the memory and configured to execute computer instructions stored on the memory to implement the light intensity correction method provided in the first aspect of the present invention.
The working principles of the above-described light intensity correction device, illumination system and microscope imaging system will be described below in connection with some embodiments of light intensity correction methods. It will be appreciated by those skilled in the art that these examples of light intensity correction methods are merely some non-limiting embodiments provided by the present invention, and are intended to clearly illustrate the general concepts of the present invention and to provide some embodiments that are convenient for public implementation, and are not intended to limit the overall functionality or overall operation of the light intensity correction device, illumination system, and microscope imaging system. Similarly, the light intensity correction device, the illumination system and the microscope imaging system are only some non-limiting embodiments provided by the present invention, and do not limit the execution subject or execution sequence of each step in the light intensity correction method.
Please further refer to fig. 2 and 3. Fig. 2 illustrates a flow chart of a light intensity correction method provided in accordance with some embodiments of the invention. Fig. 3 illustrates a schematic diagram of an optical path of a light intensity correction module provided in accordance with some embodiments of the invention.
As shown in fig. 1-3, in the process of performing light intensity correction, a technician may first use the first output light intensity distribution of the original light source 31 with respect to the field stop field of viewThe target light source size D and the target light source divergence angle max (NA) required by the Kohler lighting module 33 are used as input variables, the first target illuminance distribution required by the output end of the Kohler lighting module 33 is used as an optimization target, and the focal length of the light intensity correction module 32 is usedDistance from the original light source 31 to the light intensity correction module 32And the obscuration field of view of the original light source 31 by the light intensity correction module 32To optimize the variables, a light intensity correction model is constructed.
Specifically, the output light intensity distribution of the original light source 31 with respect to the field stop field of viewCan be expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,for maximum light intensity of the original light source 31 at different areas of the field stop field of view,is the sine value of the included angle between the light and the optical axis,describing the direction of the maximum intensity light at different areas of the field stop field of view,for the shape factor of the first output light intensity distribution, the standard deviation of the light intensity distribution is indicated,representing the obscuration factor of the original light source 31. In particular, when the field of viewWhen it is blockedWhile at the field of viewWhen not covered by the mask. Shape factorAny one or more of Gaussian distribution, lambertian distribution and exponential distribution can be selected, and random distribution in any other form can be adopted.
Further, the light intensity correction module 32 may be composed of an optical lens 321 and a field of view blocking element 322. The deflection angle of the second output light intensity distribution of the correction light source 31' obtained by the light intensity correction module 32 processing can be expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,is the focal length of the optical lens 321,the incidence height of the maximum light intensity light ray at different areas of the field diaphragm field is expressed as，Is the distance from the original light source 31 to the optical lens.
The equivalent light intensity normalized distribution obtained by superimposing the light intensity distribution at different areas of the field stop field of the correction light source 31Can be expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,is the magnification of the optical lens, expressed as。
Thus, the distribution is normalized based on the equivalent light intensityEqual to the output illuminance distribution of the kohler lighting module 33The present invention can normalize the distribution with equivalent luminous intensityTo characterize the first target illuminance distribution required at the output of the kohler illumination module 33 and determine therefrom the optimization objective of the light intensity correction model.
For example, for an optimization objective with an image plane illuminance uniformity of greater than or equal to 98%, the light intensity correction model may be expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,representing the normalized distribution of equivalent light intensityThe minimum values in the different directions,representing the normalized distribution of equivalent light intensityMaximum in different directions.
The light intensity correction device may obtain the first output light intensity distributionThe target light source size (e.g., d=5 mm), the target light source divergence angle (e.g., max (NA) =0.1), and the illuminance uniformity parameter (i.e., 98%) of the first target illuminance distribution, and solving for the light intensity correctionPositive modelTo determine the focal length of the light intensity correction module 32Distance and distanceObscuration of the field of viewAnd (5) optimizing the values of the variables.
Referring specifically to fig. 4, fig. 4 illustrates a graph of a first output light intensity distribution of an original light source with respect to a field of view of a field stop, provided in accordance with some embodiments of the present invention.
As shown in FIG. 4, the first output light intensity distribution of the primary light source 31Maximum light intensity at different areas of the field stop field of viewThe direction of the light with maximum light intensity at different areas of the field diaphragm fieldThe shape factor of the product conforms to Gaussian distribution, andand it is atThe uniformity of illuminance within the constraint range of (2) is about 84%.
In solving the light intensity correction modelThe light intensity correction means may be in the form ofAnd is also provided withIs to adjust the focal length of the scanning optical lens step by a least square methodDistance and distanceBlocking factor of field of view blocking element 322To determine the value of the functionAt least one set of optimized solutions that satisfy the illuminance uniformity parameter (i.e., 98%) of the first target illuminance distribution。
In some embodiments, the light intensity correction device may be solved for、A kind of electronic device with high-pressure air-conditioning system(i.e., without obscuration). The light intensity correction device can then correct the focal lengthDistance and distanceObscuration of the field of viewThe optical lens 321 and the field of view blocking element 322 of the light intensity correction module 32 are configured to correct the original light source 31 and obtain a corrected light source 31' satisfying the first target illuminance distribution as shown in fig. 3.
Please refer to fig. 5 and fig. 6 in combination. Fig. 5 illustrates a graph of a second light intensity distribution of a corrected light source with respect to a field stop field of view provided in accordance with some embodiments of the invention. Fig. 6 illustrates a graph of normalized light intensity for an original light source versus a corrected light source, provided in accordance with some embodiments of the invention.
As shown in fig. 5 and 6, by solving according to the optimizationAn optical lens 321 and a view field blocking element 322 of the light intensity correction module 32 are configured to correct the light intensity normalization curve of the light source 31The illuminance uniformity of (C) is significantly improved and inAnd the constraint range of the light source is more than 98 percent, and meets the requirement of the first target illuminance distribution.
It will be appreciated by those skilled in the art that the above examples of characterizing the first target illuminance distribution by illuminance uniformity are merely some non-limiting embodiments provided by the present invention, and are intended to clearly illustrate the main concepts of the present invention and to provide some specific solutions for public implementation, not to limit the scope of the present invention.
Alternatively, in other embodiments, the intensity correction module 32 may be based on any manually configured patternTo perform light intensity correction. Please refer to fig. 1, fig. 2, fig. 7 and fig. 8 in combination. Fig. 7 illustrates a schematic diagram of an optical path of a light intensity correction module provided in accordance with some embodiments of the invention. Fig. 8 illustrates a graph of normalized light intensity for an original light source versus a corrected light source, provided in accordance with some embodiments of the invention.
Taking the application scenario of the microscope imaging system shown in fig. 1 as an example, due to the image plane illuminance distribution characteristics of the fringe field of view obscuration, the large field of view aberration, the reflection loss of the lens incident at a high angle, etc., even if the illumination system 30 can form a uniform illuminance distribution on the surface of the sample 40 to be measured, the microscope imaging system can generate an uneven illuminance distribution in which the fringe field of view illuminance is smaller than the center field of view illuminance on the imaging plane of the camera 20.
To further eliminate the uneven illuminance distribution on the imaging plane of the camera 20, the light intensity correction device may also preferably acquire the image plane illuminance distribution characteristics of the microscopic imaging moduleAnd a second target illuminance distribution required at the output of the microimaging module. Here, the image plane illuminance distribution characteristics of the microimaging moduleIs caused by defects of the lens and photosensitive element of the camera 20, the lens barrel 12, the spectroscopic plate 11, and the microscope objective 13 themselves. The light intensity correction device can correct the distribution characteristic of the illumination of the image planeFor a second target illuminance distributionThe inverse variation is performed to determine a first target illuminance distribution required at the output of the kohler illumination module 33I.e.
，
For example, for an image plane illuminance distribution characteristic in which the edge field illuminance is 5% smaller than the center field illuminanceThe light intensity correction device can correspondingly distribute the first target illumination intensityEdge of (2)The field illumination is configured to be 5% greater than the central field illumination to compensate for the image plane illumination distribution characteristicsThe illumination produced at the imaging plane of the camera 20 is unevenly distributed. Accordingly, for a first target illuminance distribution having an edge field illuminance that is 5% greater than the center field illuminanceThe light intensity correction model can be expressed as:
，
wherein, the liquid crystal display device comprises a liquid crystal display device,representing a first target illuminance distributionMaximum value of the difference from the normalized distribution of the equivalent light intensity.
Thereafter, the light intensity correction means may acquire a first output light intensity distribution of the original light source 31 with respect to the field stop field of viewThe target light source size (e.g., d=5 mm) required by the kohler lighting module 33, the target light source divergence angle (e.g., max (NA) =0.18), and the first target illuminance distribution required at its outputAnd substitutes it into the light intensity correction modelSolving to determine the optical lens focal length of the intensity correction module 32Distance from the original light source 31 to the light intensity correction module 32And the obscuration field of view of the original light source 31 by the light intensity correction module 32。
In particular, in solving the light intensity correction modelThe light intensity correction means may be in the form ofAnd is also provided withIs to adjust the focal length of the scanning optical lens step by a least square methodDistance and distanceBlocking factor of field of view blocking element 322To determine the value of the functionAt least one set of optimized solutions that satisfy the illuminance uniformity parameter (i.e., 98%) of the first target illuminance distribution。
In some embodiments, the light intensity correction device may be solved for、A kind of electronic device with high-pressure air-conditioning systemIs an optimized solution of (2). Thereafter, the light intensity correction deviceCan be according to the focal lengthDistance and distanceObscuration of the field of viewThe optical lens 321 and the field of view blocking element 322 of the light intensity correction module 32 are configured to correct the original light source 31 and obtain a first target illuminance distribution as shown in FIG. 7Is provided for the correction light source 31'.
As shown in fig. 8, by solving according to the optimizationAn optical lens 321 and a view field blocking element 322 of the light intensity correction module 32 are configured to correct the light intensity normalization curve of the light source 31The value of na=0.18 is 1, and the value of na=0 is 0.95, so that illuminance uniformity compensation for the imaging plane of the camera 20 can be achieved by blocking the light energy of about 1% of the central area of the original light source 31.
Further, to verify the optimization effect of the light intensity correction scheme described above on the optical signal response of different areas of the field of view of the camera 20, some embodiments of the present invention also provide a set of graph-versus-graph plots of camera response as a function of camera field of view, i.e., FIG. 9.
As shown in fig. 9, by implementing the above-described light intensity correction method, a focal length is installed at the front end of the kohler illumination module 33 according to the result of solving the light intensity correction modelThe imaging uniformity of the camera 20 is improved from about 84% before correction to 93% after correction, greatly improving the illumination uniformity of the microscope imaging system.
Furthermore, in some embodiments of the present invention, the skilled person may further configure the microscope imaging system to the silicon wafer defect detection device to perform silicon wafer defect detection based on the description of the technical conception and the implementation manner, so as to improve the detection accuracy of the silicon wafer defect and improve the false detection rate of the silicon wafer defect.
Specifically, the above-mentioned silicon wafer defect inspection apparatus may be provided with the above-mentioned microscope imaging system provided in the fifth aspect of the present invention, and a second processor connected thereto. The second processor may collect reflected light of the illumination light at the sample 40 to be measured via the camera 20 of the microscope imaging system to generate a detection image of the sample 40 to be measured. The second processor may then analyze the inspection image to determine the wafer defect inspection results for the sample 40 under test.
In summary, the light intensity correction method, the light intensity correction device, the computer readable storage medium, the illumination system, the microscope imaging system, the silicon wafer defect detection device and the silicon wafer defect detection method provided by the invention can be used for effectively correcting the original light intensity distribution of the original light source at the front end of the kohler illumination system so as to obtain a corrected light source capable of generating target illuminance distribution on a target plane, thereby meeting the illumination uniformity requirements of various applications such as silicon wafer defect detection.
While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein or not shown and described herein, as would be understood and appreciated by those skilled in the art.
The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (14)
1. A light intensity correction method, comprising the steps of:
taking first output light intensity distribution of an original light source relative to a field of view of a field stop, a target light source size required by a Kohler lighting module and a target light source divergence angle as input variables, taking first target illuminance distribution required by an output end of the Kohler lighting module as an optimization target, and taking a focal length of a light intensity correction module, a distance from the original light source to the light intensity correction module and a blocking field of view of the light intensity correction module to the original light source as optimization variables to construct a light intensity correction model, wherein the light intensity correction module is positioned between the original light source and the Kohler lighting module;
acquiring the first output light intensity distribution, the target light source size, the target light source divergence angle and the first target illuminance distribution, and solving the light intensity correction model to determine the focal length, the distance and the obscuration field of view; and
and configuring the light intensity correction module according to the focal length, the distance and the obscuration field of view to correct the original light source so as to obtain a corrected light source meeting the first target illuminance distribution.
2. The light intensity correction method of claim 1, wherein a first output light intensity distribution of the original light source with respect to the field stop field of view is represented as:
wherein (1)>For maximum light intensity at different areas of the field stop field of view +.>Is the sine value of the included angle between the light and the optical axis, +.>Describing the direction of the maximum light intensity light ray at different areas of the field stop field of view, +.>For the shape factor of said first output light intensity distribution +.>A blocking factor representing said primary light source when the field of view is +.>Is blocked +.>When the field of view is->When not blocked->。
3. The light intensity correction method of claim 2, wherein the first output light intensity distribution is selected from a combination of any one or more of gaussian distribution, lambertian distribution, exponential distribution.
4. A light intensity correction method as claimed in claim 3, wherein the light intensity correction module is composed of an optical lens and a field of view blocking element, and the deflection angle of the second output light intensity distribution of the corrected light source obtained by processing by the light intensity correction module is expressed as:
wherein (1)>For the focal length of the optical lens, +.>The incidence height of the maximum light intensity ray at different areas of the field stop field of view on the optical lens is expressed as +.>，/>For the distance of the primary light source to the optical lens,
output illuminance distribution of the kohler illumination moduleEquivalent light intensity normalized distribution obtained by superposing light intensity distribution at different areas of the field stop field of view of the correction light source:
wherein (1)>For the magnification of the optical lens, denoted +.>。
5. The method of intensity correction according to claim 4, wherein the step of solving the intensity correction model comprises:
and solving the light intensity correction model according to the equivalent light intensity normalized distribution and the first target illuminance distribution in a constraint range of the target light source size and the target light source divergence angle required by the Kohler illumination module so as to determine the focal length, the distance and the obscuration view field.
6. A light intensity correction method as defined in claim 5, wherein the first target illuminance distribution is characterized by illuminance uniformity, the light intensity correction model being expressed as:
wherein (1)>Representing the minimum value of said normalized distribution of equivalent light intensity,/->Representing the maximum value of the normalized distribution of the equivalent light intensity, the step of solving the light intensity correction model further comprises:
scanning the focal length of the optical lens by least square methodDistance->And a blocking factor of said field of view blocking element +.>To determine the function value->At least one set of optimized solutions meeting the first target illuminance distribution。
7. The light intensity correction method of claim 5 wherein the first target illuminance distribution is represented asThe light intensity correction model is expressed as:
wherein (1)>Representing a maximum value of a difference between the first target illuminance distribution and the equivalent light intensity normalized distribution, the step of solving the light intensity correction model further includes:
scanning the focal length of the optical lens by least square methodDistance->And a blocking factor of said field of view blocking element +.>To determine the function value->Obtain the optimal solution of the minimum value>。
8. The method of claim 1, wherein the step of obtaining the first target illuminance distribution includes:
acquiring the image plane illumination distribution characteristic of the microscopic imaging module and the second target illumination distribution required by the output end of the microscopic imaging module; and
and inversely changing the second target illuminance distribution according to the image plane illuminance distribution characteristic to determine a first target illuminance distribution required by the output end of the Kohler illumination module.
9. A light intensity correction device, comprising:
a memory having stored thereon computer instructions; and
a first processor coupled to the memory and configured to execute computer instructions stored on the memory to implement the light intensity correction method of any one of claims 1-8.
10. A computer readable storage medium having stored thereon computer instructions which, when processed and executed, implement a light intensity correction method as claimed in any one of claims 1 to 8.
11. A lighting system is characterized by comprising an original light source, a light intensity correction module and a Kohler lighting module, wherein the light intensity correction module is positioned between the original light source and the Kohler lighting module,
the focal length of the light intensity correction module, the distance from the light intensity correction module to the original light source, and the obscuration field of view of the original light source by the light intensity correction module are all determined by the light intensity correction method of any one of claims 1-8.
12. A microscope imaging system, comprising:
the light splitting sheet is arranged among the camera, the sample to be detected and the illumination system according to claim 11 at a preset angle and is used for guiding illumination light outputted by the illumination system into an imaging light path of the camera on the sample to be detected;
the illumination system outputs illumination light rays meeting second target illuminance distribution required by an output end of the microscope imaging system to a sample to be detected through the first surface of the light splitting sheet and the microscope objective lens; and
and the camera acquires the reflected light of the illumination light on the sample to be detected through the second surface of the light-splitting sheet and the micro objective lens so as to generate an image of the sample to be detected.
13. The device for detecting the defects of the silicon wafer is characterized by comprising the following components:
the microscope imaging system according to claim 12; and
and the second processor is connected with a camera of the microscope imaging system and determines the detection result of the silicon wafer defect according to the image generated by the camera.
14. The method for detecting the defects of the silicon wafer is characterized by comprising the following steps of:
generating an image of a sample to be measured via a microscope imaging system according to claim 12; and
analyzing the image to determine a silicon wafer defect detection result of the sample to be detected.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004021206A (en) * | 2002-06-20 | 2004-01-22 | Olympus Corp | Light source adjusting device |
| CN102298206A (en) * | 2010-06-28 | 2011-12-28 | 索尼公司 | Microscope and focusing method |
| JP2013142774A (en) * | 2012-01-11 | 2013-07-22 | Nuflare Technology Inc | Illumination device and magnifying observation device |
| JP2017090581A (en) * | 2015-11-05 | 2017-05-25 | 有限会社ビジョンサイテック | Lighting device and observation system |
| CN111164487A (en) * | 2017-09-28 | 2020-05-15 | 株式会社片冈制作所 | Phase difference observation device and cell processing device |
| CN115248498A (en) * | 2022-08-10 | 2022-10-28 | 合肥综合性国家科学中心人工智能研究院(安徽省人工智能实验室) | Structured light super-resolution self-adaptive microscope device based on LED light source and imaging method |
| JP2023069258A (en) * | 2021-11-05 | 2023-05-18 | 株式会社エビデント | Illumination optical system and illumination device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070030948A1 (en) * | 1998-05-05 | 2007-02-08 | Carl Zeiss Smt Ag | Illumination system with field mirrors for producing uniform scanning energy |
-
2023
- 2023-06-13 CN CN202310694041.4A patent/CN116430570B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004021206A (en) * | 2002-06-20 | 2004-01-22 | Olympus Corp | Light source adjusting device |
| CN102298206A (en) * | 2010-06-28 | 2011-12-28 | 索尼公司 | Microscope and focusing method |
| JP2013142774A (en) * | 2012-01-11 | 2013-07-22 | Nuflare Technology Inc | Illumination device and magnifying observation device |
| JP2017090581A (en) * | 2015-11-05 | 2017-05-25 | 有限会社ビジョンサイテック | Lighting device and observation system |
| CN111164487A (en) * | 2017-09-28 | 2020-05-15 | 株式会社片冈制作所 | Phase difference observation device and cell processing device |
| JP2023069258A (en) * | 2021-11-05 | 2023-05-18 | 株式会社エビデント | Illumination optical system and illumination device |
| CN115248498A (en) * | 2022-08-10 | 2022-10-28 | 合肥综合性国家科学中心人工智能研究院(安徽省人工智能实验室) | Structured light super-resolution self-adaptive microscope device based on LED light source and imaging method |
Non-Patent Citations (1)
| Title |
|---|
| Comparison analysis of illumination systems for digital light microscope according to uniformity of irradiance distribution;Volodymyr Borovytskyi;SPIE;1-9 * |
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