CN117871411A - Auto-focusing optical path structure and semiconductor inspection apparatus - Google Patents

Abstract

The invention provides an auto-focusing optical path structure and a semiconductor detection device, the optical path structure comprises: the plurality of image cards are arranged at intervals on the same straight line, and the plurality of image cards are respectively provided with corresponding shading patterns; a light source assembly for emitting parallel light toward the graphic card to form graphic light; an objective lens disposed toward the sample to be detected to map the pattern light to a surface of the sample to be detected; and the detection camera is used for imaging the pattern light reflected by the sample to be detected so as to respectively analyze the definition of a plurality of shading patterns in the pattern light and then determine the image distance of the sample to be detected. The invention provides a forehead light path structure which has higher precision and higher detection efficiency compared with a laser ranging and dual-sensor ranging mode.

Description

Auto-focusing optical path structure and semiconductor inspection apparatus

Technical Field

The present application relates to the field of vehicle manufacturing technologies, and in particular, to an auto-focusing optical path structure and a semiconductor detection device.

Background

With the development of technology, many industries have higher requirements on process and defect detection, so that high-resolution optical microscopes are increasingly introduced into the field of visual detection. The existing detection mode generally comprises manual detection and automatic detection, visual fatigue is easily caused by human detection, the requirement on staff is high, the automatic detection is limited by the depth of field of an optical microscope, the depth of field of the microscope with high resolution is at a micron level at present, and the position of a shot object is slightly changed to cause blurring of a shot image, so that the automatic focusing of the microscope is needed to solve the problems.

The conventional automatic focusing ranging light paths comprise laser ranging, dual-sensor ranging and the like, and the light paths are low in precision or low in speed and cannot meet the requirements of precise semiconductor monitoring.

In view of this, the present invention has been made.

Disclosure of Invention

The application provides an automatic focusing optical path structure and semiconductor detection equipment to solve the technical problems of low precision and low speed when the existing optical path structure focuses.

The first aspect of the present invention provides an auto-focusing optical path structure comprising: the plurality of image cards are arranged at intervals on the same straight line, and the plurality of image cards are respectively provided with corresponding shading patterns; a light source assembly for emitting parallel light toward the graphic card to form graphic light; an objective lens disposed toward the sample to be detected to map the pattern light to a surface of the sample to be detected; and the detection camera is used for imaging the pattern light reflected by the sample to be detected so as to respectively analyze the definition of a plurality of shading patterns in the pattern light and then determine the image distance of the sample to be detected.

In the scheme, the light source component emits parallel light towards the image card, when the parallel light passes through the image card, the shading pattern can shade part of the parallel light, so that the parallel light is changed into pattern light with patterns on the image card, the pattern light is mapped to the surface of a sample to be detected after passing through the objective lens, as a plurality of image cards are arranged on the same straight line at equal intervals, the rear principal points of the image cards relative to the objective lens are also different, the image light reflected by the sample to be detected is imaged through the detection camera, the definition of the pattern can be determined by carrying out definition analysis on each pattern in the image light, the distance corresponding to the image card and the definition are fitted into a distance-definition function, at the moment, the highest point of the function is the image distance of the clearest point of the pattern, and the image distance can be obtained by substituting the image distance into a Gaussian imaging function, namely the distance of the sample to be detected relative to the objective lens, so that focusing of the sample to be detected is completed, and the mode of relative laser ranging and dual-sensor ranging is higher in accuracy and faster in detection efficiency.

Regarding the distance setting of the image card, the distance setting is to be set according to the distance between the fixed position of the sample to be detected and the objective lens, specifically, the fixed position of the sample to be detected is the maximum distance of the sample to be detected, the position of the objective lens is the minimum distance of the sample to be detected, a plurality of points are selected between the maximum distance and the minimum distance of the sample to be detected as object distance values, the corresponding image distance values can be obtained through a Gaussian imaging formula, and the image card is installed at a plurality of corresponding image distance value positions.

In a further aspect of the present invention, the light source assembly includes a point light source and a collimating lens, and the collimating lens is disposed between the point light source and the plurality of graphics cards, and is configured to convert light emitted from the point light source into parallel light and emit the parallel light toward the plurality of graphics cards.

In the scheme, the point light source emits scattered light to the outside, and the scattered light is converted into parallel light after passing through the collimating lens, so that stable and clear pattern light can be formed when the light passes through the image card, and the phenomenon that the pattern is not clear enough and difficult to detect due to the scattered light is avoided.

In a further aspect of the present invention, the plurality of light shielding patterns do not overlap each other in parallel light, and the plurality of image cards are arranged at equal intervals on the same straight line, so that the detecting camera can detect the definition of the plurality of light shielding patterns respectively.

In the scheme, the shading patterns on the plurality of image cards are arranged in parallel light in a mutually non-overlapping mode, so that the shading patterns on any one image card are prevented from affecting the formation of pattern light of other shading patterns, the definition analysis is more accurate, the fitted distance-definition function can be more accurate through the image cards arranged at equal intervals, the image distance of a finally obtained sample to be detected is more accurate, and the focusing of a main camera is further completed.

In a further aspect of the present invention, the auto-focusing optical path structure further includes a main camera, and an objective lens is disposed between the main camera and the sample to be detected, so that the main camera images the sample to be detected through the objective lens.

In the scheme, the main camera is used for imaging the sample to be detected, and the object lens is arranged between the main camera and the sample to be detected, so that reflected light of the sample to be detected enters the main camera for imaging after passing through the object lens, and the sample to be detected is detected.

In a further aspect of the invention, the primary camera is configured to image light in a first wavelength band, the detection camera is configured to image light in a second wavelength band, the point source is configured to emit light in a third wavelength band, the first wavelength band is at least partially coincident with the second wavelength Duan Huchi, and the third wavelength band is at least partially coincident with the second wavelength band.

In this scheme, because the light that the pointolite sent is the third wavelength band, third wavelength band and second wavelength band partial coincidence, consequently the detection camera of the light of formation of image second wavelength band can carry out shaping to the light that the pointolite sent to accomplish the definition analysis, so that the main camera focuses on, because the main camera is used for carrying out the formation of image to the light of first wavelength band, and first wavelength band is mutually exclusive with the second wavelength band, consequently the light that the pointolite sent can not cause the interference to the formation of image of main camera, thereby can be better wait to detect the sample.

In a further aspect of the present invention, the auto-focusing optical path structure further includes a reflection assembly, where the reflection assembly includes a first beam splitter and a second beam splitter, and the first beam splitter and the second beam splitter are disposed in parallel, so that the pattern light is refracted from the objective lens to the surface of the sample to be detected by bypassing the main camera.

In this scheme, can bypass the main camera with image light and follow the objective refraction to wait to detect the sample surface through the reflection subassembly, consequently light source subassembly and picture card need not to set up between main camera and wait to detect the sample, avoid causing the interference to the formation of image of main camera, first spectroscope and second spectroscope parallel arrangement can make image light follow the perpendicular mapping of second spectroscope on waiting to detect the sample to can improve the accuracy of follow-up definition analysis, and then make the image distance of the waiting to detect the sample that obtains more accurate.

In a further scheme of the invention, the second spectroscope is arranged between the main camera and the objective lens, and the first spectroscope and the plurality of image cards are arranged on the same straight line so as to reflect the image light to the second spectroscope and map the image light to the sample to be detected; the first spectroscope is arranged between the detection camera and the second spectroscope so that the detection camera detects pattern light of the sample to be detected, which is transmitted through the first spectroscope after being reflected by the second spectroscope.

In the scheme, the second spectroscope is arranged between the main camera and the objective lens, the first spectroscope and the plurality of image cards are arranged on the same straight line, so that image light passing through the image cards can be reflected from the first spectroscope to the second spectroscope, the first spectroscope and the second spectroscope are mutually parallel, the image light can be mapped to the surface of a sample to be detected, the sample to be detected and the image light mapped on the surface of the sample to be detected can be reflected, after passing through the objective lens, the image light is reflected to the first spectroscope by the second spectroscope, then the image light passing through the first windy spectroscope is received by the detection camera, the image light formed by the plurality of shading patterns can be subjected to definition analysis by the detection camera, and a distance-definition function can be synthesized according to definition obtained by the definition analysis and distances among the plurality of image cards, and at the moment, the highest point in the distance-definition function is the image distance of the sample to be detected.

In a further scheme of the invention, the first spectroscope and the second spectroscope are both plated with a spectroscope film, and the spectroscope film is used for spectroscope a fourth wavelength band which is mutually exclusive with the first wavelength band and comprises a third wavelength band.

In the scheme, the light splitting films are plated on the first spectroscope and the second spectroscope and used for splitting light of a fourth wavelength band, and the fourth wavelength band is mutually exclusive with the first wavelength band, so that the light splitting films cannot influence the light of the first wavelength band, the light of the first wavelength band reflected by a sample to be detected directly passes through the first spectroscope to enter a main camera for imaging after passing through the objective lens, and therefore the imaging of the sample to be detected by the main camera is clearer, and the sample to be detected is detected more accurately; because the fourth wavelength band includes the third wavelength band, the portion, overlapping with the third wavelength band, of the second wavelength band emitted by the light source assembly splits light at the first beam splitter and the second beam splitter, so that the camera to be detected can receive the pattern light to complete the definition analysis.

In a specific application, the first wavelength band is visible light, the second wavelength band, the third wavelength band and the fourth wavelength band are infrared light, that is, the detection camera is an infrared camera, the first spectroscope and the second spectroscope can only split infrared light, the visible light can be completely transmitted through the first spectroscope and the second spectroscope, and the point light source is a light source for emitting infrared light.

In a further aspect of the present invention, an angle between the first beam splitter and the parallel light is 45 ° so that the parallel light and the pattern light refracted from the second beam splitter onto the sample to be detected are parallel to each other.

In this scheme, through making the contained angle of first spectroscope and parallel light be 45, therefore when image light maps to first spectroscope, the angle of reflection is perpendicular with the angle of incidence, the pattern light after the reflection is perpendicular with parallel light promptly, again because first spectroscope and second spectroscope parallel arrangement, therefore the pattern light after the relative parallel light of second spectroscope and the reflection of first spectroscope is all perpendicular, therefore the pattern light after the reflection of second spectroscope is perpendicular relative parallel light, the pattern light that the second spectroscope was reflected can perpendicularly map to the surface of waiting to detect the sample this moment, thereby can improve the definition of pattern.

In the specific application, a shading structure is arranged among the plurality of image cards, the light source assembly, the reflecting assembly and the detection camera, so that the analysis of the definition caused by the influence of external interference is avoided, and similarly, the shading structure is also independently arranged between the objective lens and the main camera, so that the definition of the detection can be improved.

The second aspect of the present invention provides a semiconductor inspection apparatus, including the autofocus optical path structure provided in the first aspect of the present invention, where the sample to be inspected is a wafer.

In summary, the auto-focusing optical path structure and the semiconductor detection device provided by the present application have at least the following beneficial effects:

the light source assembly emits parallel light towards the image card, when the parallel light passes through the image card, the shading pattern can shade part of the parallel light, so that the parallel light is changed into pattern light with patterns on the image card, the pattern light is mapped to the surface of a sample to be detected after passing through the objective lens, and as a plurality of image cards are arranged on the same straight line at equal intervals, the rear principal points of the image cards relative to the objective lens are also different, the image light reflected by the sample to be detected is imaged through the detection camera, the definition of the pattern can be determined by carrying out definition analysis on each pattern in the image light, the distance corresponding to the image card and the definition are fitted into a distance-definition function, at the moment, the highest point of the function is the image distance of the clearest point of the pattern, and the image distance can be obtained by substituting the image distance into the Gaussian imaging function, namely the distance of the sample to be detected relative to the objective lens, so that focusing of the sample to be detected is completed, the relative laser ranging and the dual-sensor ranging modes are higher in accuracy and faster in detection efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are used in the description of the embodiments or the prior art will be briefly described below. It will be apparent that the figures in the following description are some embodiments of the present application, and that other figures can be obtained from these figures without inventive effort to those skilled in the art.

Fig. 1 is a schematic structural diagram of an optical path structure of auto-focusing according to an embodiment of the present application;

FIG. 2 is a functional diagram of a sharpness analysis provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a graphics card according to an embodiment of the present application; and

fig. 4 is a diagram of a patterned light provided in an embodiment of the present application.

The reference numerals are as follows:

100. a light source assembly; 110. a point light source; 120. a collimating lens;

200. a graphics card; 200A, shading pattern; 210. a first graphic card; 220. a second graphic card; 230. a third graphic card; 240. a fourth graphic card; 250. a fifth graphic card;

300. an objective lens; 400. a sample to be detected; 500. detecting a camera; 600. a main camera;

700. a reflective assembly; 710. a first spectroscope; 720. and a second beam splitter.

Detailed Description

In the description of the present application, it should be understood that, if there are descriptions of terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating orientation or positional relationship, it should be understood that the orientation or positional relationship shown based on the drawings is merely for convenience of description and simplification of the description, and does not indicate or imply that the apparatus or element in question must have a specific orientation, be configured and operated in a specific orientation, and should not be construed as limiting the present application.

Furthermore, the presence of features defining "first" and "second" for descriptive purposes only, should not be interpreted as indicating or implying a relative importance or implicitly indicating the number of features indicated. Features defining "first", "second" may include at least one such defined feature, either explicitly or implicitly. If a description of "a plurality" is present, the generic meaning includes at least two, e.g., two, three, etc., unless specifically defined otherwise.

In this application, unless explicitly stated or limited otherwise, terms such as "mounted," "connected," "secured," and the like, are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; the connection may be mechanical connection, electrical connection, direct connection, indirect connection through an intermediate medium, communication between two elements or interaction relationship between two elements. The specific meaning of the terms in the present application can be understood by those skilled in the art according to the specific circumstances.

In the description of the present specification, the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., as used herein, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Referring to fig. 1, a first aspect of the present invention provides an auto-focusing optical path structure, including: the plurality of image cards 200 are arranged at intervals on the same straight line, and the plurality of image cards 200 are respectively provided with corresponding shading patterns 200A; the light source assembly 100 emits parallel light toward the graphic card 200 to form graphic light; an objective lens 300 disposed toward the sample 400 to be detected to map the pattern light to the surface of the sample 400 to be detected; and a detection camera 500 for imaging the pattern light reflected by the sample 400 to be detected, so as to determine the image distance of the sample 400 to be detected after performing resolution analysis on the plurality of shading patterns 200A in the pattern light.

In this scheme, when the light source assembly 100 emits parallel light toward the image card 200 and the parallel light passes through the image card 200, the light shielding pattern 200A shields part of the parallel light, so that the parallel light becomes pattern light with a pattern on the image card 200, and the pattern light is mapped onto the surface of the sample 400 to be detected after passing through the objective lens 300.

It should be noted that, the position of the sample 400 to be detected is fixed and known (e.g. fixed on a certain detecting table), the image distance of the sample 400 to be detected will change with the thickness of the sample 400 to be detected, so that the obtained image distance will also substantially obtain the thickness of the sample 400 to be detected, and the objective lens 300 is the objective lens 300 of the main camera 600, which needs to be selected according to the test requirement. The gaussian imaging formula referred to herein is the following formula:

where f is the focal length of objective lens 300, u is the object distance, and v is the image distance.

Regarding the distance setting of the image card 200, the distance setting is to be set according to the distance between the fixed position of the sample 400 to be detected and the objective 300, specifically, the fixed position of the sample 400 to be detected is the maximum distance of the sample 400 to be detected, the position of the objective 300 is the minimum distance of the sample 400 to be detected, a plurality of points are selected between the maximum distance and the minimum distance of the sample 400 to be detected as object distance values, and the corresponding image distance values can be obtained through a gaussian imaging formula, and then the image card 200 is installed at a plurality of corresponding image distance value positions.

In a further embodiment, the light source assembly 100 includes a point light source 110 and a collimating lens 120, and the collimating lens 120 is disposed between the point light source 110 and the plurality of graphics cards 200, and is configured to convert light emitted from the point light source 110 into parallel light and emit the parallel light toward the plurality of graphics cards 200.

Referring to fig. 2, in the sharpness analysis, after the pattern light is imaged by the inspection camera 500, the image is analyzed by software to determine the sharpness of the pattern formed by each graphic card 200.

In this scheme, the point light source 110 emits scattered light to the outside, and the scattered light is converted into parallel light after passing through the collimating lens 120, so that stable and clear pattern light can be formed when the light passes through the graphic card 200, and the scattered light is prevented from causing the pattern to be unclear and difficult to detect.

In a further embodiment, the plurality of light shielding patterns 200A are not overlapped with each other in parallel light, and the plurality of graphics cards 200 are arranged at equal intervals on the same line, so that the detecting camera 500 can detect the sharpness of the plurality of light shielding patterns 200A, respectively.

In this scheme, the light shielding patterns 200A on the plurality of graphics cards 200 are not overlapped in parallel light, so that the light shielding patterns 200A on any one graphics card 200 are prevented from affecting the formation of the graphics light of other light shielding patterns 200A, so that the definition analysis is more accurate, the distance-definition function of fitting can be more accurate by the graphics cards 200 arranged at equal intervals, the image distance of the finally obtained sample 400 to be detected is more accurate, and the focusing of the main camera 600 is further completed.

Referring to fig. 2, the optical path structure is selected from five cards 200, that is, the optical path structure includes a first card 210, a second card 220, a third card 230, a fourth card 240 and a fifth card 250, the light shielding patterns 200A on the cards 200 are three thick transverse lines, the angles of the three thick transverse lines on the cards 200 are different, specifically, the light shielding patterns 200A on any two cards 200 are arranged in a circumferential array relative to the axis, so that the plurality of cards 200 are not overlapped in parallel light, thereby avoiding errors generated during the resolution analysis, the finally formed image light is shown in fig. 3, the MTF is the resolution in fig. 4, and the image distance of the sample 400 to be detected at present is obviously known between the second card 220 and the third card 230 in the drawing.

Specifically, the first, second, third, fourth, and fifth cards 210, 220, 230, 240, and 250 should be slidably connected to the locations where they are installed, so that the first, second, third, fourth, and fifth cards 210, 220, 230, 240, and 250 can be easily adjusted in position, and fixing structures should be provided to fix the first, second, third, fourth, and fifth cards 210, 220, 230, 240, and 250 after the positions are determined, and the cards 200 can be increased or decreased according to the needs.

In a further embodiment, the auto-focusing optical path structure further comprises a main camera 600, and the objective lens 300 is disposed between the main camera 600 and the sample 400 to be detected, such that the main camera 600 images the sample 400 to be detected via the objective lens 300.

In this scheme, the main camera 600 is used for imaging the sample 400 to be detected, and by disposing the objective lens 300 between the main camera 600 and the sample 400 to be detected, reflected light of the sample 400 to be detected enters the main camera 600 to be imaged after passing through the objective lens 300, thereby completing detection of the sample 400 to be detected.

In a further embodiment, the primary camera 600 is used to image light in a first wavelength band, the detection camera 500 is used to image light in a second wavelength band, the point source 110 is used to emit light in a third wavelength band, the first wavelength band is at least partially coincident with the second wavelength Duan Huchi, and the third wavelength band is at least partially coincident with the second wavelength band.

In this embodiment, since the light emitted by the point light source 110 is in the third wavelength band, and the third wavelength band partially coincides with the second wavelength band, the detection camera 500 for imaging the light in the second wavelength band can shape the light emitted by the point light source 110, so as to perform sharpness analysis, so that the main camera 600 focuses, and since the main camera 600 is used for imaging the light in the first wavelength band, the first wavelength band is mutually exclusive to the second wavelength band, the light emitted by the point light source 110 does not interfere with the imaging of the main camera 600, so that the sample 400 to be detected can be better detected.

In a further embodiment, the auto-focusing optical path structure further includes a reflection assembly 700, and the reflection assembly 700 includes a first beam splitter 710 and a second beam splitter 720, and the first beam splitter 710 and the second beam splitter 720 are disposed in parallel, so that the pattern light is refracted from the objective lens 300 to the surface of the sample 400 to be detected by bypassing the main camera 600.

In this scheme, the reflection assembly 700 is used to refract the image light around the main camera 600 from the objective lens 300 to the surface of the sample 400 to be detected, so that the light source assembly 100 and the image card 200 are not required to be arranged between the main camera 600 and the sample 400 to be detected, interference to imaging of the main camera 600 is avoided, the first beam splitter 710 and the second beam splitter 720 are arranged in parallel, and the image light can be vertically mapped on the sample 400 to be detected from the second beam splitter 720, so that accuracy of subsequent definition analysis can be improved, and a more accurate distance-definition function can be obtained through definition analysis, so that an obtained image distance of the sample 400 to be detected is more accurate.

In a further embodiment, the second beam splitter 720 is disposed between the main camera 600 and the objective lens 300, and the first beam splitter 710 and the plurality of graphics cards 200 are disposed on the same line, so as to reflect the graphics light to the second beam splitter 720 and map the graphics light onto the sample 400 to be detected; the first beam splitter 710 is disposed between the detection camera 500 and the second beam splitter 720, so that the detection camera 500 detects the pattern light of the sample 400 to be detected that is transmitted through the first beam splitter 710 after being reflected by the second beam splitter 720.

In this embodiment, the second beam splitter 720 is disposed between the main camera 600 and the objective lens 300, and since the first beam splitter 710 and the plurality of image cards 200 are disposed on the same straight line, the image light passing through the image cards 200 is reflected from the first beam splitter 710 to the second beam splitter 720, and since the first beam splitter 710 and the second beam splitter 720 are parallel to each other, the image light is mapped to the surface of the sample 400 to be detected, the sample 400 to be detected and the image light mapped on the surface thereof are reflected, after passing through the objective lens 300, reflected by the second beam splitter 720 to the first beam splitter 710, and then received by the detection camera 500 through the first prism, the image light formed by the plurality of light-shielding patterns 200A can be subjected to a resolution analysis, and the resolution obtained according to the resolution analysis and the distances between the plurality of image cards 200 can be synthesized into a distance-resolution function, and the highest point in the distance-resolution function is the image distance of the sample 400 to be detected.

In a further embodiment, the first beam splitter 710 and the second beam splitter 720 are both coated with a beam splitting film for splitting a fourth wavelength band, which is mutually exclusive from the first wavelength band and includes a third wavelength band.

In this scheme, by plating the first beam splitter 710 and the second beam splitter 720 with a light splitting film, the light splitting film is used for splitting light of a fourth wavelength band, and the fourth wavelength band is mutually exclusive from the first wavelength band, so that the light splitting film cannot affect the light of the first wavelength band, and the light of the first wavelength band reflected by the sample 400 to be detected directly passes through the first beam splitter 710 to enter the main camera 600 for imaging after passing through the objective lens 300, so that the imaging of the sample 400 to be detected by the main camera 600 is clearer, and the sample 400 to be detected is detected more accurately; since the fourth wavelength band includes the third wavelength band, the portion of the second wavelength band emitted by the light source assembly 100 overlapping the third wavelength band is split at the first beam splitter 710 and the second beam splitter 720, so that the camera 500 to be detected can receive the pattern light to complete the sharpness analysis.

In a specific application, the first wavelength band is visible light, the second wavelength band, the third wavelength band and the fourth wavelength band are infrared light, that is, the detection camera 500 is an infrared camera, the first beam splitter 710 and the second beam splitter 720 can only split infrared light, and the visible light can be completely transmitted through the first beam splitter 710 and the second beam splitter 720, and the point light source 110 is a light source for emitting infrared light.

In a further embodiment, the angle between the first beam splitter 710 and the parallel light is 45 °, so that the parallel light and the pattern light refracted from the second beam splitter 720 onto the sample 400 to be detected are parallel to each other.

In this embodiment, the included angle between the first beam splitter 710 and the parallel light is 45 °, so when the image light is mapped onto the first beam splitter 710, the reflected angle is perpendicular to the incident angle, that is, the reflected pattern light is perpendicular to the parallel light, and because the first beam splitter 710 and the second beam splitter 720 are disposed in parallel, the second beam splitter 720 is perpendicular to the parallel light and the pattern light reflected by the first beam splitter 710, the pattern light reflected by the second beam splitter 720 is perpendicular to the parallel light, and at this time, the pattern light reflected by the second beam splitter 720 is perpendicularly mapped onto the surface of the sample 400 to be detected, thereby improving the pattern definition.

In a further scheme, a light shielding structure should be disposed among the plurality of graphics cards 200, the light source assembly 100, the reflection assembly 700 and the detection camera 500, so as to avoid the influence of external interference on the analysis of the sharpness, and similarly, a light shielding structure should be separately disposed between the objective lens 300 and the main camera 600, so as to improve the sharpness of the detection.

The second aspect of the present invention provides a semiconductor inspection apparatus, including the autofocus optical path structure provided in the first aspect of the present invention, where the sample 400 to be inspected is a wafer.

In this scheme, through autofocus's light path structure, can focus the wafer more fast to more convenient detect the wafer, relatively traditional focus mode, response speed is fast, can reach several hundred frames/second, with upper and lower link seamless connection, do not influence system efficiency.

Although embodiments of the present application have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives, and variations may be made to the above embodiments by those skilled in the art within the scope of the application.

Claims (10)

1. An autofocus optical path structure comprising:

a plurality of image cards (200) which are arranged at intervals on the same straight line, wherein the image cards (200) are respectively provided with corresponding shading patterns (200A);

a light source assembly (100) for emitting parallel light toward the graphic card (200) to form a graphic light;

an objective lens (300) arranged towards a sample (400) to be detected to map the patterned light to a surface of the sample (400) to be detected; and

and the detection camera (500) is used for imaging the pattern light reflected by the sample (400) to be detected so as to respectively analyze the definition of the plurality of shading patterns (200A) in the pattern light and then determine the image distance of the sample (400) to be detected.

2. The auto-focusing optical path structure according to claim 1, wherein the light source assembly (100) includes a point light source (110) and a collimating lens (120), the point light source (110), the collimating lens (120) and the plurality of graphics cards (200) are sequentially disposed on a same straight line, and the collimating lens (120) is disposed between the point light source (110) and the plurality of graphics cards (200) and is configured to convert light emitted by the point light source (110) into parallel light and emit the parallel light toward the plurality of graphics cards (200).

3. The auto-focusing optical path structure according to claim 1, wherein the plurality of light shielding patterns (200A) are not overlapped with each other in parallel light, and the plurality of image cards (200) are arranged at equal intervals on the same straight line so that the detecting camera (500) can detect the sharpness of the plurality of light shielding patterns (200A) respectively.

4. The autofocus optical path structure according to claim 2, further comprising a main camera (600), the objective lens (300), and the sample (400) to be detected being disposed in order on a same straight line, the objective lens (300) being disposed between the main camera (600) and the sample (400) to be detected, such that the main camera (600) images the sample (400) to be detected via the objective lens (300).

5. The autofocus optical path structure of claim 4, wherein said primary camera (600) is configured to image light in a first wavelength band, said detection camera (500) is configured to image light in a second wavelength band, said point light source (110) is configured to emit light in a third wavelength band, said first wavelength band being mutually exclusive of said second wavelength band, said third wavelength band being at least partially coincident with said second wavelength band.

6. The auto-focusing optical path structure according to claim 5, further comprising a reflection assembly (700), wherein the reflection assembly (700) comprises a first beam splitter (710) and a second beam splitter (720), the first beam splitter (710) and the second beam splitter (720) are parallel to each other, and the first beam splitter (710), the second beam splitter (720) and the detection camera (500) are sequentially arranged on the same straight line, so that the pattern light is refracted from the objective lens (300) to the surface of the sample (400) to be detected by bypassing the main camera (600).

7. The auto-focusing optical path structure according to claim 6, wherein the second beam splitter (720) is disposed between the main camera (600) and the objective lens (300), and the first beam splitter (710) and the plurality of graphics cards (200) are disposed on the same line so as to reflect the graphic light to the second beam splitter (720) and map onto the sample (400) to be detected;

the main camera (600), the second beam splitter (720), the objective lens (300) and the sample (400) to be detected are sequentially arranged on the same straight line, and the first beam splitter (710) is arranged between the detection camera (500) and the second beam splitter (720), so that the detection camera (500) detects pattern light of the sample (400) to be detected, which is transmitted through the first beam splitter (710) after being reflected by the second beam splitter (720).

8. The autofocus optical path structure of claim 6, wherein,

the first spectroscope (710) and the second spectroscope (720) are both plated with a light splitting film, the light splitting film is used for splitting light of a fourth wavelength band, and the fourth wavelength band comprises the third wavelength band and is mutually exclusive with the first wavelength band.

9. The autofocus optical path structure of claim 6, wherein,

the included angle between the first spectroscope (710) and the parallel light is 45 degrees, so that the parallel light and the pattern light refracted from the second spectroscope (720) onto the sample (400) to be detected are parallel to each other.

10. A semiconductor inspection apparatus comprising the autofocus optical path structure of any of claims 1-9, wherein the sample (400) to be inspected is a wafer.