CN112697800B

CN112697800B - Defect detection device and method

Info

Publication number: CN112697800B
Application number: CN202011450397.6A
Authority: CN
Inventors: 杨朝兴
Original assignee: Shanghai Yuwei Semiconductor Technology Co ltd
Current assignee: Shanghai Yuwei Semiconductor Technology Co ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2022-08-26
Anticipated expiration: 2040-12-09
Also published as: CN112697800A

Abstract

The invention provides a defect detection device and a method, wherein the defect detection device comprises a dark field illumination light source, an imaging lens, a full Stokes polarization integral camera, a motion platform and a control unit, wherein the dark field illumination light source is used for providing a linearly polarized light beam, and the motion platform is used for bearing a sample to be detected; the linearly polarized light beam is obliquely projected onto a sample to be measured, is reflected and scattered by the sample to be measured to form a signal light beam, and the signal light beam is projected to the full Stokes polarization integral camera after passing through the imaging lens; the control unit drives the motion platform to move, so that the full Stokes polarization integral camera finishes scanning and shooting of a sample to be detected to simultaneously form a full Stokes polarization picture, and defect detection is carried out after a mirror surface reflection signal in data is filtered through data processing of the full Stokes polarization picture to obtain defect information of the sample to be detected; the invention improves the speed and accuracy of defect detection and identification.

Description

Defect detection device and method

Technical Field

The present invention relates to optical inspection technologies, and in particular, to a defect detection apparatus and method.

Background

AOI (Automated Optical Inspection) equipment is used as an Optical-based defect detection tool, and is widely applied to industries such as solar cells, integrated circuits, display panels and the like to realize rapid nondestructive detection of defects of masks and silicon wafers.

The traditional AOI defect detection device usually utilizes bright field, dark field and backlight illumination modes to illuminate a detected sample, thereby increasing a defect signal to be detected, inhibiting background signals and environmental noise of the sample and improving the signal-to-noise ratio of the defect signal. And then, detecting the defects of the sample to be detected at high speed through a high-resolution lens and a camera. And finally, realizing correct identification and classification of the defects through a software algorithm, and feeding back the detected defects to a user for rechecking, clearing or defect repair. The correctness of defect identification and classification directly influences the workload and effect of subsequent re-inspection, removal or defect repair operation, thereby influencing the production efficiency of the whole integrated circuit and display panel production line.

However, the sample to be tested may have a mirror-like area due to the manufacturing process, and for example, the edge of the metal mask used for evaporation may generate a mirror-like metal bevel due to the manufacturing process. The strong reflected light from the specular area may cover the weak signal of real defects near the area. The conventional AOI inspection apparatus cannot detect real defects in the vicinity of the reflection light in such a case. In addition, the conventional AOI inspection apparatus may also identify the reflection of the mirror surface area as a defect, thereby causing a large number of false detections, and increasing the workload of subsequent re-inspection, cleaning, or defect repair operations.

Disclosure of Invention

The embodiment of the invention provides a defect detection device and method, so that the defect detection and identification speed and accuracy are improved.

In a first aspect, an embodiment of the present invention provides a defect detection apparatus, including a dark field illumination light source, an imaging lens, a full stokes polarization integration camera, a motion stage and a control unit, where the dark field illumination light source is configured to provide a linearly polarized light beam, and the motion stage is configured to carry a sample to be detected;

the linearly polarized light beam is obliquely projected onto a sample to be detected, is reflected and scattered by the sample to be detected to form a signal light beam, and the signal light beam passes through the imaging lens and is projected to the full-stokes polarization integral camera;

the full-stokes polarization integral camera comprises a plurality of pixel lines and a plurality of polarization elements and is used for obtaining the total light intensity I0 of the signal light beam, the light intensity Ix of linearly polarized light in the polarization direction of 0 degree or the light intensity Iy of linearly polarized light in the polarization direction of 90 degrees in the signal light beam, and the light intensity I of the linearly polarized light in the polarization direction of 45 degrees in the signal light beam ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity of left-handed circularly polarized light I in the signal beam _L Or the intensity I of right-handed circularly polarized light _R ；

The plurality of polarizing elements comprise a first polarizing element, a second polarizing element and a third polarizing element, the first polarizing element is used for transmitting linear polarization in the polarization direction of 0 degree or linear polarization in the polarization direction of 90 degrees in the signal light beam, the second polarizing element is used for transmitting linear polarization in the polarization direction of 45 degrees or linear polarization in the polarization direction of 135 degrees in the signal light beam, and the third polarizing element is used for transmitting left circularly polarized light or right circularly polarized light in the signal light beam;

the control unit drives the motion platform to move, so that the full Stokes polarization integral camera finishes scanning and shooting on the sample to be detected to simultaneously form a full Stokes polarization picture, and defect detection is carried out after a mirror surface reflection signal in the data is filtered through data processing on the full Stokes polarization picture to obtain defect information of the sample to be detected;

wherein each pixel point in the full stokes polarization picture comprises a stokes vector [ S0, S1, S2, S3 ].

Optionally, the linearly polarized light beam is P-polarized light.

Optionally, the dark field illumination light source includes a first light source and a linear polarization filter, the first light source is an annular light source, and a light beam emitted by the first light source passes through the linear polarization filter and is then formed into the linearly polarized light beam; or,

the dark field illumination light source comprises a second light source, a plurality of polarization maintaining optical fibers and a plurality of optical fiber outlets, the second light source is used for providing linearly polarized light beams, the linearly polarized light beams emitted by the second light source are emitted after passing through the plurality of polarization maintaining optical fibers and the plurality of optical fiber outlets, and the plurality of optical fiber outlets are encircled to form a ring.

Optionally, the full stokes polarization integrating camera comprises 4N pixel rows and 3N polarizing elements arranged along the scanning direction; n is a positive integer greater than 1;

the adjacent 4 pixel rows form a pixel row combination unit, the pixel row combination units are repeatedly arranged along the scanning direction, one pixel row combination unit comprises a first pixel row, a second pixel row, a third pixel row and a fourth pixel row, and the adjacent 3 polarizing elements comprise a first polarizing element, a second polarizing element and a third polarizing element;

in each pixel row combination unit, the first polarization element covers the second pixel row, the second polarization element covers the third pixel row, and the third polarization element covers the fourth pixel row.

Optionally, the full stokes polarization integrating camera includes 4 pixel row sub-arrays and 3 polarization elements arranged along a scanning direction, each pixel row sub-array includes N pixel rows arranged repeatedly, and N is a positive integer greater than 1;

the 4 pixel row sub-arrays are respectively a first pixel row sub-array, a second pixel row sub-array, a third pixel row sub-array and a fourth pixel row sub-array, and the 3 polarizing elements are respectively a first polarizing element, a second polarizing element and a third polarizing element;

the first polarizing element covers the second sub-array of pixel rows, the second polarizing element covers the third sub-array of pixel rows, and the third polarizing element covers the fourth sub-array of pixel rows.

Optionally, the full stokes polarization integrating camera comprises N pixel rows arranged repeatedly along a scanning direction, each of the pixel rows comprises 4M pixels, and the full stokes polarization integrating camera further comprises 3N × M polarizing elements; m, N are all positive integers greater than 1;

in the same pixel row, 4 adjacent pixels form a pixel combination unit, the pixel combination units are respectively and repeatedly arranged along the row direction and the scanning direction, and one pixel combination unit comprises a first pixel, a second pixel, a third pixel and a fourth pixel; 3 polarizing elements are correspondingly arranged on the photosensitive sides of the three pixels in each pixel combination unit, and the 3 polarizing elements comprise a first polarizing element, a second polarizing element and a third polarizing element;

in each pixel combination unit, the first polarizing element covers the second pixel, the second polarizing element covers the third pixel, and the third polarizing element covers the fourth pixel.

Optionally, the full stokes polarization integrating camera comprises N pixel rows arranged repeatedly along a scanning direction, each of the pixel rows comprises 4M pixels, and the full stokes polarization integrating camera further comprises 3M polarization elements; m, N are all positive integers greater than 1;

in the same pixel row, 4 adjacent pixels form a pixel combination unit, the pixel combination unit is repeatedly arranged along a row direction and a scanning direction respectively, one pixel combination unit comprises a first pixel, a second pixel, a third pixel and a fourth pixel, 3 adjacent polarizing elements comprise a first polarizing element, a second polarizing element and a third polarizing element, the first pixel, the second pixel, the third pixel and the fourth pixel are repeatedly arranged along the scanning direction respectively to form a first pixel column, a second pixel column, a third pixel column and a fourth pixel column, and the first pixel column, the second pixel column, the third pixel column and the fourth pixel column are adjacent to form a pixel column combination unit;

in each pixel column combination unit, the first polarizing element covers N second pixels arranged in the scanning direction, the second polarizing element covers N third pixels arranged in the scanning direction, and the third polarizing element covers N fourth pixels arranged in the scanning direction.

Optionally, the first polarizing element includes a first linear polarizer, a transmission axis of the first linear polarizer is 0 ° or 90 °, the second polarizing element includes a second linear polarizer, a transmission axis of the second linear polarizer is 45 ° or 135 °, the third polarizing element includes a quarter-wave plate and a third linear polarizer, an included angle between a fast axis of the quarter-wave plate and a transmission axis of the third linear polarizer is 45 ° or 135 °, and the quarter-wave plate is located on an optical path between the third linear polarizer and the pixel row; or,

the first polarizing element, the second polarizing element and the third polarizing element all adopt super surface elements.

In a second aspect, an embodiment of the present invention provides a defect detection method, including:

providing a linearly polarized light beam by using a dark field illumination light source;

driving a motion table to move, and enabling a full stokes polarization integral camera to complete scanning shooting of a sample to be tested so as to form a full stokes polarization picture, wherein each pixel point in the full stokes polarization picture comprises a stokes vector [ S0, S1, S2, S3 ];

performing defect detection after filtering out a mirror reflection signal in the data by data processing of the full Stokes polarization picture to obtain defect information of the sample to be detected;

wherein the full Stokes polarization integrating camera comprises a plurality of pixel lines and a plurality of polarization elements for acquiring the signal lightTotal light intensity I0 of the beam, light intensity Ix of linearly polarized light with a polarization direction of 0 degree or light intensity Iy of linearly polarized light with a polarization direction of 90 degree in the signal beam, and light intensity I of linearly polarized light with a polarization direction of 45 degree in the signal beam ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity I of left-handed circularly polarized light in the signal beam _L Or the intensity I of right-handed circularly polarized light _R ；

The plurality of polarizing elements comprise a first polarizing element, a second polarizing element and a third polarizing element, the first polarizing element is used for transmitting linear polarization in the polarization direction of 0 degree or linear polarization in the polarization direction of 90 degrees in the signal light beam, the second polarizing element is used for transmitting linear polarization in the polarization direction of 45 degrees or linear polarization in the polarization direction of 135 degrees in the signal light beam, and the third polarizing element is used for transmitting left circular polarization or right circular polarization in the signal light beam.

Optionally, the processing of the data of the full stokes polarization picture is performed to filter out a mirror reflection signal in the data and then perform defect detection, so as to obtain defect information of the sample to be detected, where the defect information includes:

locating a specular reflection region in the full stokes polarization picture;

setting polarization filtering parameters, carrying out polarization filtering simulation by taking the polarization filtering parameters and the data of the full Stokes polarization picture as parameters, and filtering out mirror reflection signals in the data;

when the light intensity of the mirror reflection area in the filtered data output by simulation is smaller than a preset value, outputting a filtered light intensity graph;

and acquiring the defect area distribution of the sample to be detected according to the filtered light intensity diagram.

Optionally, after obtaining the defect area distribution of the sample to be detected according to the filtered light intensity map, the method further includes:

obtaining a defect polarization diagram of each defect according to the defect region distribution of the sample to be detected and the full Stokes polarization picture;

and clustering and classifying the defects according to the defect polarization diagram of each defect.

The embodiment of the invention provides a defect detection device, which adopts linearly polarized light beams emitted by a dark field illumination light source as illumination light beams of a sample to be detected, shoots the sample to be detected through a full Stokes polarization integral camera to obtain a full Stokes polarization picture, wherein each pixel point in the full Stokes polarization picture comprises a Stokes vector, and the Stokes vector can represent the state of any polarized light including the polarization degree. Therefore, compared with the conventional optical imaging method which utilizes light intensity information for imaging, the embodiment of the invention utilizes the full stokes polarization picture to record more information in the signal light beam reflected by the sample to be detected, and the full stokes polarization picture not only comprises the light intensity information but also comprises the polarization information, so that in the subsequent process, the control unit can extract the polarization information in the full stokes polarization picture through data processing of the full stokes polarization picture, and after the mirror reflection signal in the data is filtered, the defect scattering light is not interfered by the mirror reflection light, and then the defect detection is carried out to obtain the defect information of the sample to be detected, thereby improving the defect detection and identification accuracy. In addition, when the processing technology of the sample to be detected changes, the control unit can correspondingly change the algorithm of the mirror reflection signal in the filtered data without rotating and moving the optical element, the response speed is high, and the light intensity suppression scheme can be customized quickly aiming at a specific technology, so that the defect detection and identification speed is improved.

Drawings

FIG. 1 is a schematic view of a metal film punch cut angle and particle defect scattering under dark field illumination;

FIG. 2 is a schematic view of metal film punch cut angle and particle defect scattering under P-polarized dark field illumination;

fig. 3 is a schematic structural diagram of a defect detection apparatus according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a dark field illumination light source according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of another dark field illumination source according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a full stokes polarization integrating camera according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a pixel arrangement according to an embodiment of the invention;

FIG. 8 is a schematic view of the arrangement of polarizing elements corresponding to the pixel arrangement shown in FIG. 7;

FIG. 9 is a schematic diagram of another pixel arrangement according to an embodiment of the present invention;

FIG. 10 is a schematic view of the arrangement of polarizing elements corresponding to the pixel arrangement shown in FIG. 9;

FIG. 11 is a schematic view of another pixel arrangement according to an embodiment of the present invention;

FIG. 12 is a schematic view of the arrangement of polarizing elements corresponding to the pixel arrangement shown in FIG. 11;

FIG. 13 is a schematic view of another pixel arrangement according to an embodiment of the present invention;

FIG. 14 is a schematic view of the arrangement of polarizing elements corresponding to the pixel arrangement shown in FIG. 11;

FIG. 15 is a flowchart illustrating a defect detection method according to an embodiment of the present invention;

fig. 16 is a flowchart illustrating another defect detection method according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic diagram of a metal film stamping cut angle and particle defect scattering under a dark field illumination condition, and referring to fig. 1, a detection process of a common particle defect 1 'on a metal film is illustrated, wherein the metal film may be, for example, a mask, and the mask includes a metal cut angle 2' caused by a metal film stamping process and inclined planes formed on upper and lower surfaces of the metal film. The oblique incident dark field illumination light beam (unpolarized light) illuminates the common particle defect 1 ', part of the light is absorbed by the common particle defect 1 ', part of the light is scattered by the common particle defect 1 ', the scattered light is collected by the imaging lens and finally imaged on the surface of the sensor, and the scattered light is converted into an electric signal by the sensor and output to a computer for defect detection. Since the imaging lens can only collect light signals within its maximum numerical aperture range, only a portion of the scattered light signals can be captured and detected by photographing. In contrast, the dark field illumination beam impinging on the metal chamfer 2' is then predominantly specularly reflected, with most of the light being reflected along the dashed line in the figure, through the imaging lens and ultimately imaged at the sensor surface. Most of the light is reflected by the metal chamfer 2 'and is detected by the sensor through the imaging lens, so that the reflected light intensity of the metal chamfer 2' obtained by the detection device is far greater than the reflected light intensity of the common particle defect 1 ', and the common particle defect 1' cannot be detected.

Fig. 2 is a schematic view showing a metal film punching cut angle and a particle defect scattering under a P-polarized dark field illumination condition, and referring to fig. 2, unlike fig. 1, the P-polarized dark field illumination condition is adopted in fig. 2, that is, a P-polarized dark field illumination beam (P-polarized light) is adopted as an illumination beam. When the P polarized dark field illumination light beam irradiates the common particle defect 1 ', part of the light beam is absorbed by the common particle defect 1 ', and the rest of the light beam is scattered to all directions by the common particle defect 1 '. The scattered light is generally elliptically polarized light. The P-polarized dark field illumination beam is still linearly polarized after being specularly reflected by the metal chamfer 2'. Therefore, only the linearly polarized light in the same direction as the metal chamfer reflected light needs to be filtered out at the sensor end through the polarization detection device, and the reflected light caused by the metal chamfer 2' can be effectively reduced. However, the linearly polarized light reflected by the metal chamfer has different polarization directions due to different reflection angles, and the linearly polarized light reflected by the metal chamfer can be effectively absorbed by the corresponding rotation polarization detection device, so that the difficulty of arranging the polarization detection device at the sensor end is increased.

Fig. 3 is a schematic structural diagram of a defect detection apparatus according to an embodiment of the present invention, and referring to fig. 3, the defect detection apparatus includes a dark field illumination light source 4, an imaging lens 2, a full stokes polarization integrating camera 1, a motion stage 6, and a control unit 8. The dark field illumination source 4 is used to provide a linearly polarized light beam. The motion table 6 is used for bearing a sample 5 to be measured. Dark field illumination lightThe linear polarized light beam emitted by the source 4 is obliquely projected onto the sample 5 to be measured, is reflected and scattered by the sample 5 to be measured to form a signal light beam, and the signal light beam passes through the imaging lens 2 and is projected to the full stokes polarization integral camera 1 to be imaged on the full stokes polarization integral camera 1. The full stokes polarization integrating camera 1 comprises a plurality of pixel rows 11 and a plurality of polarization elements 12, and is used for acquiring total light intensity I0 of a signal light beam, light intensity Ix of linearly polarized light in the polarization direction of 0 degree or light intensity Iy of linearly polarized light in the polarization direction of 90 degrees in the signal light beam, and light intensity I of linearly polarized light in the polarization direction of 45 degrees in the signal light beam ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity of left-handed circularly polarized light I in signal beam _L Or the intensity I of right-handed circularly polarized light _R (ii) a The plurality of polarization elements 12 include a first polarization element 121, a second polarization element 122, and a third polarization element 123, where the first polarization element 121 is configured to transmit linear polarization in a polarization direction of 0 ° or linear polarization in a polarization direction of 90 ° in the signal beam, the second polarization element 122 is configured to transmit linear polarization in a polarization direction of 45 ° or linear polarization in a polarization direction of 135 ° in the signal beam, and the third polarization element 123 is configured to transmit left circularly polarized light or right circularly polarized light in the signal beam.

With reference to fig. 3, the control unit 8 drives the moving stage 6 to move, so as to drive the sample 5 to be measured to move, and the full stokes polarization integration camera 1 and the sample 5 to be measured generate relative displacement, so that the full stokes polarization integration camera 1 finishes scanning and shooting the sample 5 to be measured, and the full stokes polarization integration camera 1 forms a full stokes polarization picture. Each pixel point in the full Stokes polarized picture comprises a Stokes vector [ S0, S1, S2 and S3]]And the Stokes vector of each pixel point is obtained by calculating the light intensity of the signal light beam collected by the pixel point. Wherein, the full Stokes polarization integral camera 1 obtains the total light intensity I0, the light intensity Ix of linear polarization in the polarization direction of 0 degree or the light intensity Iy of linear polarization in the polarization direction of 90 degrees, and the light intensity I of linear polarization in the polarization direction of 45 degrees ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity of left-handed circularly polarized light I _L Or the intensity I of right-handed circularly polarized light _R And, Ix + Iy＝I0，I ₄₅ +I ₁₃₅ ＝I0，I _L +I _R I0, so knowing I0, one can compute from the other, I x and Iy, and one can compute the other, I ₄₅ And I ₁₃₅ One calculates the other, can pass through I _L And I _R One compute the acquisition of the other. Based on this, the stokes vector is calculated from the following relation: s0 ═ I0, S1 ═ Ix-Iy, S2 ═ I ₄₅ -I ₁₃₅ ，S3＝I _L -I _R . Further, the control unit 8 performs defect detection after filtering out the mirror reflection signal in the data by processing the data of the full stokes polarization picture, and acquires the defect information of the sample to be detected.

The embodiment of the invention provides a defect detection device, which adopts linearly polarized light beams emitted by a dark field illumination light source 4 as illumination light beams of a sample 5 to be detected, shoots the sample 5 to be detected through a full Stokes polarization integral camera 1 to obtain a full Stokes polarization picture, wherein each pixel point in the full Stokes polarization picture comprises a Stokes vector, and the Stokes vector can represent the state of any polarized light including the polarization degree. Therefore, compared with the conventional optical imaging method using light intensity information, the embodiment of the invention uses the full stokes polarization picture to record more information in the signal light beam reflected by the sample 5 to be detected, and the full stokes polarization picture includes both the light intensity information and the polarization information, so that in the subsequent process, the control unit 8 can extract the polarization information in the full stokes polarization picture through data processing of the full stokes polarization picture, and after the mirror reflection signal in the data is filtered, the defect scattered light is not interfered by the mirror reflection light, and then the defect detection is performed to obtain the defect information of the sample to be detected, thereby improving the defect detection and identification accuracy. In addition, when the processing technology of the sample 5 to be detected changes, the control unit 8 can correspondingly change the algorithm for filtering the mirror reflection signal in the data without rotating and moving the optical element, the response speed is high, and the light intensity suppression scheme can be customized quickly aiming at a specific technology, so that the defect detection and identification speed is improved.

Alternatively, referring to fig. 3, the linearly polarized light beam is P-polarized light. That is, the light beam emitted from the dark field illumination light source 4 is P-polarized light. The linear polarized light beam emitted by the dark field illumination light source 4 is obliquely projected onto the sample 5 to be measured, and the reflected light intensity of the P polarized light under the large-angle light illumination condition is lower than that of the S polarized light, so that the P polarized light can be selected under the dark field illumination condition to effectively inhibit reflection.

Fig. 4 is a schematic structural diagram of a dark field illumination light source according to an embodiment of the present invention, and referring to fig. 3 and 4, the dark field illumination light source 4 includes a first light source 41 and a linear polarization filter 42, the first light source 41 is an annular light source, and a light beam emitted by the first light source 41 is formed into a linearly polarized light beam after passing through the linear polarization filter 42.

Exemplarily, referring to fig. 4, the dark field illumination light source 4 may further include an annular light source frame 43, and the first light source 41 and the linear polarization filter 42 are fixed on the annular light source frame 43.

Fig. 5 is a schematic structural diagram of a dark field illumination light source according to an embodiment of the present invention, and referring to fig. 3 and 5, the dark field illumination light source 4 includes a second light source (not shown in fig. 5), a plurality of polarization maintaining optical fibers 44, and a plurality of optical fiber outlets 45. The second light source is used for providing linearly polarized light beams, the linearly polarized light beams emitted by the second light source are emitted after passing through the plurality of polarization maintaining optical fibers 44 and the plurality of optical fiber outlets 45, and the plurality of optical fiber outlets 45 form a ring around the ring, so that the dark field illumination light source 4 can provide ring-shaped linearly polarized light.

Illustratively, referring to fig. 5, dark field illumination light source 4 may further include an annular light source frame 43, and a plurality of polarization maintaining fibers 44 and a plurality of fiber outlets 45 are fixed to annular light source frame 43.

Fig. 6 is a schematic structural diagram of a full stokes polarization integrating camera according to an embodiment of the present invention, and referring to fig. 6, a full stokes polarization integrating camera 1 includes a sensor 10 and a polarization element 12 disposed on a light incident side of the sensor 10, where the sensor 10 includes a plurality of pixel pixels arranged in an array, the plurality of pixel pixels form a pixel row along a first direction, and the plurality of pixel rows are arranged along a second direction. Specifically, a plurality of different kinds of polarization elements 12 can be disposed on the photosensitive side of the pixel array, as the case may be.

Fig. 7 is a schematic diagram of a pixel arrangement according to an embodiment of the present invention, fig. 8 is a schematic diagram of an arrangement of a polarization element corresponding to the pixel arrangement shown in fig. 7, and referring to fig. 6, fig. 7 and fig. 8, a plurality of pixel pixels arranged in an array in a sensor 10 form a pixel row 11 along a row direction X, and a plurality of pixel rows 11 are arranged along a scanning direction Y. Illustratively, the full stokes polarization integrating camera 1 includes 4N pixel rows 11 and 3N polarizing elements 12 arranged along the scanning direction Y, N being a positive integer greater than 1. The adjacent 4 pixel rows 11 constitute a pixel row combination unit, and one pixel row combination unit includes a first pixel row 111, a second pixel row 112, a third pixel row 113, and a fourth pixel row 114. The pixel row combination units are repeatedly arranged along the scanning direction Y, and in this example, the full stokes polarization integrating camera 1 includes N pixel row combination units. The photosensitive side of the three pixel rows in each pixel row combination unit is correspondingly provided with 3 polarizing elements, and the 3 polarizing elements 12 comprise a first polarizing element 121, a second polarizing element 122 and a third polarizing element 123. The first polarizer 121 is used to transmit linear polarization of 0 ° polarization direction or linear polarization of 90 ° polarization direction. The second polarizing element 122 is configured to transmit linearly polarized light with a polarization direction of 45 ° or linearly polarized light with a polarization direction of 135 °. The third polarizing element 123 is configured to transmit left circularly polarized light or right circularly polarized light. Illustratively, as shown in fig. 8, in each pixel row combination unit, the first pixel row 111 is not covered by the polarization element 12 (illustrated by a dashed box at a position corresponding to the first pixel row 111), so that the first pixel row 111 can obtain the total light intensity I0. The first polarizing element 121 covers the second pixel row 112 so that the second pixel row 112 can acquire the light intensity Ix of the linearly polarized light of the polarization direction of 0 ° or the light intensity Iy of the linearly polarized light of the polarization direction of 90 °. The second polarizing element 122 covers the third pixel row 113 so that the third pixel row 113 can acquire the light intensity I of linearly polarized light of 45 ° polarization direction ₄₅ Or linearly polarized light with a polarization direction of 135 DEG ₁₃₅ . The third polarization element 123 covers the fourth pixel row 114, so that the fourth pixel row 114 can acquire the intensity I of left-handed circularly polarized light _L Or the intensity I of right-handed circularly polarized light _R . In the examples of the present invention, phasesThe distance between the centers of two adjacent polarizing elements 12 is the width of one pixel row 11, and if the arrangement direction of the plurality of polarizing elements 12 is inclined with respect to the scanning direction Y, the inclination causes the lateral shift of the polarizing elements 12 to be relatively small and negligible.

Fig. 9 is another schematic diagram of a pixel arrangement provided in an embodiment of the present invention, fig. 10 is a schematic diagram of an arrangement of polarization elements corresponding to the pixel arrangement shown in fig. 9, and referring to fig. 6, fig. 9 and fig. 10, the full stokes polarization integration camera 1 includes 4 pixel line sub-arrays and 3 polarization elements 12 arranged along the scanning direction Y, each pixel line sub-array includes N pixel lines 11 arranged repeatedly, where N is a positive integer greater than 1. The 4 pixel row sub-arrays are a first pixel row sub-array 131, a second pixel row sub-array 132, a third pixel row sub-array 133, and a fourth pixel row sub-array 134, respectively. The 3 polarizing elements are a first polarizing element 121, a second polarizing element 122, and a third polarizing element 123, respectively. The first polarizer 121 is used to transmit linear polarization of 0 ° polarization direction or linear polarization of 90 ° polarization direction. The second polarizing element 122 is configured to transmit linearly polarized light with a polarization direction of 45 ° or linearly polarized light with a polarization direction of 135 °. The third polarizing element 123 is configured to transmit left circularly polarized light or right circularly polarized light. Illustratively, as shown in fig. 10, the first pixel row sub-array 131 is not covered with the polarization element 12 (illustrated with a dashed box at a position corresponding to the first pixel row sub-array 131), so that the first pixel row sub-array 131 can acquire the total light intensity I0. The first polarization element 121 covers the second pixel row sub-array 132 so that the second pixel row sub-array 132 can acquire the light intensity Ix of the linear polarization of the polarization direction of 0 ° or the light intensity Iy of the linear polarization of the polarization direction of 90 °. The second polarization element 122 covers the third pixel row sub-array 133 so that the third pixel row sub-array 133 can acquire the light intensity I of linearly polarized light in the polarization direction of 45 ° ₄₅ Or linearly polarized light with a polarization direction of 135 DEG ₁₃₅ . The third polarizing element 123 covers the fourth pixel row sub-array 134 so that the fourth pixel row sub-array 134 can acquire the intensity I of left-handed circularly polarized light _L Or the intensity I of right-handed circularly polarized light _R . Since each polarizing element 12 in the present embodiment covers oneIn the pixel row sub-array, the full stokes polarization integration camera 1 in the embodiment of the present invention can obtain full stokes polarization pictures only by setting three polarization elements 12 (the first polarization element 121, the second polarization element 122, and the third polarization element 123), so that the number of the polarization elements 12 is reduced, the size of the polarization elements 12 does not need to be set to the pixel level, and the setting difficulty of the polarization elements 12 in the full stokes polarization integration camera 1 is reduced.

Fig. 11 is a schematic diagram of another pixel arrangement provided in an embodiment of the present invention, fig. 12 is a schematic diagram of an arrangement of polarization elements corresponding to the pixel arrangement shown in fig. 11, and referring to fig. 6, fig. 11 and fig. 12, the full stokes polarization integration camera 1 includes N pixel rows 11 repeatedly arranged along the scanning direction Y, each pixel row 11 includes 4M pixel pixels, and the full stokes polarization integration camera 1 further includes 3N × M polarization elements 12. M, N are all positive integers greater than 1. In the same pixel row 11, adjacent 4 pixel pixels constitute one pixel combination unit, and one pixel combination unit includes a first pixel1, a second pixel2, a third pixel3, and a fourth pixel 4. The pixel combination units are repeatedly arranged along the row direction X and the scanning direction Y, respectively, and in this embodiment, the full stokes polarization integration camera 1 includes N × M pixel combination units. It should be noted that the first pixel1, the second pixel2, the third pixel3, and the fourth pixel4 are different names given for convenience of phonetic description, and the first pixel1, the second pixel2, the third pixel3, and the fourth pixel4 may have the same structure. The photosensitive side of the three pixels in each pixel combination unit is correspondingly provided with 3 polarizing elements 12, the 3 polarizing elements 12 comprise a first polarizing element 121, a second polarizing element 122 and a third polarizing element 123, and the first polarizing element 121 is used for transmitting linear polarization in the polarization direction of 0 degrees or linear polarization in the polarization direction of 90 degrees. The second polarizing element 122 is configured to transmit linearly polarized light with a polarization direction of 45 ° or linearly polarized light with a polarization direction of 135 °. The third polarizing element 123 is configured to transmit left-circularly polarized light or right-circularly polarized light. Illustratively, as shown in FIG. 12, in each pixel combination cell, the first pixel1 is not covered by the polarizing element 12 (in correspondence with the first image)The position of the pixel1 is indicated with a dashed box) so that the first pixel1 can obtain the total light intensity I0. The first polarizing element 121 covers the second pixel2 so that the second pixel2 can acquire the light intensity Ix of the linear polarization of the polarization direction of 0 ° or the light intensity Iy of the linear polarization of the polarization direction of 90 °. The second polarizing element 122 covers the third pixel3 so that the third pixel3 can acquire the light intensity I of linearly polarized light of 45 ° polarization direction ₄₅ Or linearly polarized light with a polarization direction of 135 DEG ₁₃₅ . The third polarizing element 123 covers the fourth pixel4 so that the fourth pixel4 can acquire the intensity I of left-handed circularly polarized light _L Or the intensity I of right-handed circularly polarized light _R . In the embodiment of the invention, the difference between the basic structure of the sensor 10 and the structure of a common integral camera sensor is minimum, and the manufacturing difficulty of the full-stokes polarization integral camera 1 is reduced. On the other hand, since the pixel combination units are repeatedly arranged in the scanning direction Y, the order (number of rows) of the sensor 10 is not sacrificed, and the signal-to-noise ratio is not affected. Under the condition of the same number of pixel rows 11, the signal-to-noise ratio of the sensor 10 in the full stokes polarization integration camera 1 provided by the embodiment of the invention is the highest, and the full stokes polarization integration camera has the highest shooting speed.

Fig. 13 is a schematic diagram of a pixel arrangement according to an embodiment of the present invention, fig. 14 is a schematic diagram of an arrangement of polarization elements corresponding to the pixel arrangement shown in fig. 13, and referring to fig. 6, fig. 13, and fig. 14, the full stokes polarization integration camera 1 includes N pixel rows 11 repeatedly arranged along the scanning direction Y, each pixel row 11 includes 4M pixel pixels, and the full stokes polarization integration camera 1 further includes 3M polarization elements 12, M, N both being positive integers greater than 1. In the same pixel row 11, adjacent 4 pixel pixels constitute one pixel combination unit, and one pixel combination unit includes a first pixel1, a second pixel2, a third pixel3, and a fourth pixel 4. The pixel combination units are repeatedly arranged along the row direction X and the scanning direction Y respectively, and the first pixel1, the second pixel2, the third pixel3 and the fourth pixel4 are repeatedly arranged along the scanning direction Y respectively to form a first pixel column, a second pixel column, a third pixel column and a fourth pixel column which are adjacent to each otherThe pixel column, the third pixel column, and the fourth pixel constitute a pixel column combination unit, that is, in this embodiment, the full stokes polarization integration camera 1 includes M pixel column combination units, the photosensitive sides of 3 pixel columns in each pixel column combination unit are respectively provided with a different kind of polarization element, and the 3 polarization elements 12 include a first polarization element 121, a second polarization element 122, and a third polarization element 123. The first polarizer 121 is used to transmit linear polarization of 0 ° polarization direction or linear polarization of 90 ° polarization direction. The second polarizing element 122 is configured to transmit linearly polarized light with a polarization direction of 45 ° or linearly polarized light with a polarization direction of 135 °. The third polarizing element 123 is configured to transmit left-circularly polarized light or right-circularly polarized light. Illustratively, as shown in fig. 14, in each pixel column combination unit, the first pixel column is not covered by the polarization element 12 (indicated by a dashed box at a position corresponding to the first pixel column), so that the first pixel column can acquire the total light intensity I0. The first polarizing element 121 covers N second pixel columns arranged in the scanning direction Y, so that the second pixel columns can acquire the light intensity Ix of the linear polarization in the polarization direction of 0 ° or the light intensity Iy of the linear polarization in the polarization direction of 90 °. The second polarizing element 122 covers N third pixel columns arranged in the scanning direction, so that the third pixel columns can acquire the light intensity I of linearly polarized light in the polarization direction of 45 ° ₄₅ Or linearly polarized light with a polarization direction of 135 DEG ₁₃₅ . The third polarizing element 123 covers N fourth pixel pixels 4 arranged in the scanning direction so that the fourth pixel column can acquire the intensity I of left-handed circularly polarized light _L Or the intensity I of right-handed circularly polarized light _R 。

Illustratively, referring to fig. 7 and 8, when the full stokes polarization integrating camera 1 scans and photographs the sample 5 to be measured, the same portion of the sample 5 to be measured is successively exposed through a plurality of first pixel rows 111 arranged along the scanning direction Y, and after signals of the plurality of first pixel rows 111 are accumulated together, the signals are processed and amplified by the readout line 5 and then output to a subsequent device or a buffer. Similarly, when the full stokes polarization integrating camera 1 scans and photographs the sample 5 to be measured, signals of the plurality of second pixel rows 112, the plurality of third pixel rows 113 and the plurality of fourth pixel rows 114 arranged along the scanning direction Y are also respectively accumulated, and are output to subsequent devices or buffers after being processed and amplified by the readout line 5. The full stokes polarization integral camera 1 adopted by the embodiment of the invention improves the signal to noise ratio under the condition of weak light through time delay integration, so that the full stokes polarization integral camera 1 can still keep a high enough photographing speed under the condition that the incident light intensity is reduced due to polarization splitting, and the defect rapid detection is realized. The first pixel row 111 comprises a first type of polarization modulating element which acquires an intensity of light which is the corresponding polarized intensity, e.g. Ix. Similarly, the remaining three pixel rows will also acquire the corresponding polarized light intensities. The 4 kinds of polarized light intensity signals are collected by the 4 kinds of pixel rows and output to a subsequent calculation circuit through a readout line 115. The subsequent calculation circuit calculates the stokes vectors of the respective pixel points from the polarized light intensity signals using the above-mentioned method [ S0, S1, S2, S3 ].

For example, for the structures shown in fig. 7 and 8 or the structures shown in fig. 9 and 10, the stokes vector of one pixel is obtained by cumulatively calculating the polarized light intensity signals of a column of pixels in fig. 7 or 9, and the stokes vectors of the pixels represented by different columns are calculated relatively independently. Illustratively, for the structures shown in fig. 11 and 12 or the structures shown in fig. 13 and 14, the stokes vector of one pixel point is obtained by cumulatively calculating the polarized light intensity signals of adjacent 4 pixel columns in fig. 11 or 13. For the structure in the latter example, 4 columns of pixels are required to obtain the stokes vector information of 1 pixel, so the spatial resolution of the full stokes polarization integrating camera 1 in the row direction is reduced by 4 times. However, the number of signal lines (i.e., the number of orders) accumulated in the column direction is 4 times higher than that in the previous example, so that the signal-to-noise ratio is better, and better imaging can be obtained under low-light or high-speed shooting conditions. Alternatively, referring to fig. 7 to 14, the first polarizing element 121 includes a first linear polarizer having a transmission axis of 0 ° or 90 °, so that a linear polarization of a polarization direction of 0 ° or a linear polarization of a polarization direction of 90 ° may be transmitted. The second polarizing element 122 comprises a second linearly polarizing plate having a transmission axis of 45 ° or 135 ° so that linearly polarized light of 45 ° polarization direction or 135 ° polarization direction can be transmitted. The third polarizing element 123 includes a quarter-wave plate and a third linear polarizer, an included angle between a fast axis of the quarter-wave plate and a transmission axis of the third linear polarizer is 45 ° or 135 °, and the quarter-wave plate is located on a light path between the third linear polarizer and the pixel row, so that left circularly polarized light or right circularly polarized light can be transmitted. In other embodiments, the first polarization element 121, the second polarization element 122 and the third polarization element 123 may also employ super-surface elements, and the polarization element 12 transmitting different polarized light is implemented by providing different surface structures for different super-surface elements.

Based on the same inventive concept, an embodiment of the present invention further provides a defect detection method, fig. 15 is a schematic flow chart of the defect detection method provided in the embodiment of the present invention, and referring to fig. 15, the defect detection method includes:

and S101, providing a linearly polarized light beam by using the dark field illumination light source 4.

The linear polarized light beam emitted by the dark field illumination light source 4 is obliquely projected onto the sample 5 to be measured, and is reflected and scattered by the sample 5 to be measured to form a signal light beam.

And S102, driving the motion platform 6 to move, and enabling the full Stokes polarization integral camera 1 to complete scanning shooting of the sample 5 to be detected so as to form a full Stokes polarization picture.

The full stokes polarization integral camera 1 comprises a plurality of pixel rows 11 and a plurality of polarization elements 12, and is used for acquiring total light intensity I0 of a signal light beam, light intensity Ix of linearly polarized light in the polarization direction of 0 degree or light intensity Iy of linearly polarized light in the polarization direction of 90 degree in the signal light beam, and light intensity I of linearly polarized light in the polarization direction of 45 degree in the signal light beam ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity of left-handed circularly polarized light I in signal beam _L Or the intensity I of right-handed circularly polarized light _R (ii) a The plurality of polarization elements 12 include a first polarization element 121, a second polarization element 122 and a third polarization element 123, the first polarization element 121 is used for transmitting the linear polarization of 0 ° polarization direction or the linear polarization of 90 ° polarization direction in the signal beamThe second polarizer 122 is configured to transmit linearly polarized light with a polarization direction of 45 ° or linearly polarized light with a polarization direction of 135 ° in the signal beam, and the third polarizer 123 is configured to transmit left circularly polarized light or right circularly polarized light in the signal beam.

Each pixel point in the full Stokes polarization picture comprises a Stokes vector [ S0, S1, S2 and S3]]Wherein, the full Stokes polarization integral camera 1 obtains the total light intensity I0, the light intensity Ix of the linear polarization in the polarization direction of 0 degree or the light intensity Iy of the linear polarization in the polarization direction of 90 degrees and the light intensity I of the linear polarization in the polarization direction of 45 degrees ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity of left-handed circularly polarized light I _L Or the intensity I of right-handed circularly polarized light _R ；Ix+Iy＝I0，I ₄₅ +I ₁₃₅ ＝I0，I _L +I _R I0, the stokes vector is calculated from the following relation: s0 ═ I0, S1 ═ Ix-Iy, S2 ═ I ₄₅ -I ₁₃₅ ，S3＝I _L -I _R 。

In this step, the moving platform 6 is driven to move, so that the moving platform 6 drives the sample 5 to be detected to move, the full stokes polarization integral camera 1 and the sample 5 to be detected generate relative displacement, the full stokes polarization integral camera 1 finishes scanning and shooting of the sample 5 to be detected, and the full stokes polarization integral camera 1 forms a full stokes polarization picture.

S103, through data processing of the full Stokes polarization picture, defect detection is carried out after a mirror reflection signal in the data is filtered, and defect information of the sample to be detected is obtained.

The embodiment of the invention provides a defect detection method based on the defect detection device in the embodiment, linear polarized light beams emitted by a dark field illumination light source 4 are used as illumination light beams of a sample 5 to be detected, the sample 5 to be detected is shot through a full stokes polarization integral camera 1, a full stokes polarization picture is obtained, each pixel point in the full stokes polarization picture comprises a stokes vector, and the stokes vector can represent the state of any polarized light including the polarization degree. Therefore, compared with the conventional optical imaging method which utilizes light intensity information for imaging, the full stokes polarization picture records more information in the signal light beam reflected by the sample 5 to be detected, and the full stokes polarization picture not only comprises the light intensity information but also comprises the polarization information, so that in the subsequent process, the polarization information in the full stokes polarization picture can be extracted through data processing of the full stokes polarization picture, after the mirror reflection signal in the data is filtered, the defect scattered light cannot be interfered by the mirror reflection light, then the defect detection is carried out, the defect information of the sample to be detected is obtained, and the defect detection and identification accuracy is improved. In addition, when the processing technology of the sample 5 to be detected changes, the control unit 8 can correspondingly change the algorithm for filtering the mirror reflection signal in the data without rotating and moving the optical element, the response speed is high, and the light intensity suppression scheme can be customized quickly aiming at a specific technology, so that the defect detection and identification speed is improved.

Optionally, before step S101, the defect detection method may further include: setting measurement parameters, wherein setting measurement parameters may include, for example: the scanning line frequency of the full stokes polarization integration camera 1 is set, the moving speed of the motion stage 6 is set, and the light emission intensity of the dark field illumination light source 4 is set.

Fig. 16 is a schematic flowchart of another defect detection method according to an embodiment of the present invention, and referring to fig. 16, the defect detection method includes:

s201, providing a linearly polarized light beam by using a dark field illumination light source.

S202, driving the motion platform to move, and enabling the full Stokes polarization integral camera to complete scanning shooting of the sample to be detected so as to form a full Stokes polarization picture.

And S203, positioning a specular reflection area in the full Stokes polarization picture.

In this step, since the light intensity of the specular reflection area is much greater than the light intensity of the defect scattered light, for example, the reflected light intensity of the metal chamfer 2 'obtained by the detection device is much greater than the reflected light intensity of the normal particle defect 1'. Therefore, which region is the specular reflection region can be located according to the light intensity level according to the total light intensity. For example, a region where the light intensity of the total light intensity is greater than a preset value is identified as the specular reflection region.

S204, setting polarization filtering parameters, carrying out polarization filtering simulation by taking the polarization filtering parameters and the data of the full Stokes polarization picture as parameters, and filtering out mirror surface reflection signals in the data.

In this step, the region where the polarization filtering parameter is set may be, for example, only a specular reflection region, and the region outside the specular reflection region in the full stokes polarization picture is not set with the polarization filtering parameter, so that the specular reflection signal is filtered out in a region-specific manner, and meanwhile, the original data outside the specular reflection region in the full stokes polarization picture is kept without being affected, thereby improving the precision of defect detection. In other embodiments, the polarization filtering parameters may be set for all regions corresponding to the whole full stokes polarization picture, which is not limited in the present invention.

The polarization filtering parameters may include, for example, parameters for realizing linear polarization filtering, and the effect of filtering the data of the full stokes polarization picture by the polarization filtering parameters is equivalent to that a signal beam is transmitted through a linear polarizer for filtering so as to retain elliptically polarized light scattered by the common particle defect 1 'and filter linearly polarized light reflected by the metal corner cut 2' mirror.

S205, outputting a filtered light intensity graph when the light intensity of the mirror reflection area in the filtered data output by the simulation is smaller than a preset value.

In this step, when a polarization filter parameter is set in step S204, there is a corresponding set of light intensity data of the specular reflection area. When the polarization filtering parameters are changed, the light intensity data of the specular reflection area are changed accordingly. When the light intensity of the mirror reflection area in the filtered data output by simulation is smaller than a preset value, the mirror reflection signal does not affect the normal defect identification signal, the signal-to-noise ratio is high, the filtered light intensity graph can be output, and the defect detection step is executed according to the filtered light intensity graph.

And S206, acquiring the defect area distribution of the sample 5 to be detected according to the filtered light intensity diagram.

In the defect detection method provided by the embodiment of the invention, the specular reflection area in the full Stokes polarization picture is firstly positioned, namely the exposure point is positioned, then the polarization filtering parameter is set at the exposure point, and when the polarization filtering parameter is changed, the light intensity data of the specular reflection area is changed accordingly. When the light intensity of the mirror reflection area in the filtered data output by simulation is smaller than a preset value, the mirror reflection signal does not affect the normal defect identification signal, the signal to noise ratio is higher, and then the defect area distribution of the sample 5 to be detected is obtained according to the filtered light intensity diagram, so that the defect detection and identification accuracy is improved.

Optionally, after step S206, the defect detection method may further include the steps of:

step one, obtaining a defect polarization diagram of each defect according to the defect region distribution of the sample 5 to be detected and a full Stokes polarization picture.

In this step, after the defect area distribution is obtained in step S206, the positions of the plurality of defect areas are located, and the data of the plurality of defect areas are selected, that is, a plurality of defect polarization maps for the defects are obtained. Each pixel in the defect polarization map includes a stokes vector (one for each pixel).

And step two, clustering and classifying the defects according to the defect polarization diagram of each defect.

In this step, polarization information may be extracted from the defect polarization map of each defect, and the polarization information includes information such as a degree of polarization, a polarization direction distribution, and light intensity. Because different polarization states can be generated by different objects or different states (roughness, void degree, water content and the like) of the same object, the defects can be clustered and classified according to the polarization information extracted from the defect polarization diagram.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. The defect detection device is characterized by comprising a dark field illumination light source, an imaging lens, a full Stokes polarization integral camera, a motion platform and a control unit;

the dark field illumination light source is used for providing linearly polarized light beams, the motion platform is used for bearing a sample to be tested, the linearly polarized light beams are obliquely projected onto the sample to be tested, are reflected and scattered by the sample to be tested to form signal light beams, and the signal light beams are projected to the full Stokes polarization integrating camera after passing through the imaging lens;

the control unit drives the motion platform to move, so that the full-stokes polarization integral camera finishes scanning and shooting the sample to be detected to simultaneously form a full-stokes polarization picture, and performs defect detection after a mirror surface reflection signal in the data is filtered through data processing of the full-stokes polarization picture to acquire defect information of the sample to be detected;

each pixel point in the full stokes polarization picture comprises a stokes vector [ S0, S1, S2 and S3 ];

the defect detection is carried out after the data processing of the full stokes polarization picture and the filtering of the mirror reflection signal in the data, and the defect information of the sample to be detected is obtained, and the defect detection comprises the following steps:

locating a specular reflection region in the full stokes polarization picture;

acquiring the defect area distribution of the sample to be detected according to the filtered light intensity diagram;

after the defect area distribution of the sample to be detected is obtained according to the filtered light intensity diagram, the method further comprises the following steps:

2. The defect inspection device of claim 1, wherein the linearly polarized light beam is P polarized light.

3. The defect detecting apparatus according to claim 1, wherein the dark field illumination light source comprises a first light source and a linear polarization filter, the first light source is an annular light source, and a light beam emitted by the first light source is formed into the linearly polarized light beam after passing through the linear polarization filter; or,

the dark field illumination light source comprises a second light source, a plurality of polarization maintaining optical fibers and a plurality of optical fiber outlets, the second light source is used for providing linearly polarized light beams, the linearly polarized light beams emitted by the second light source are emergent after passing through the plurality of polarization maintaining optical fibers and the plurality of optical fiber outlets, and the plurality of optical fiber outlets surround to form a ring.

4. The defect detection apparatus of claim 1, wherein the full stokes polarization integrating camera comprises 4N pixel rows and 3N polarizing elements arranged along a scan direction; n is a positive integer greater than 1;

in each pixel row combination unit, the first polarizing element covers the second pixel row, the second polarizing element covers the third pixel row, and the third polarizing element covers the fourth pixel row.

5. The defect detection device of claim 1, wherein the full stokes polarization integrating camera comprises 4 pixel row sub-arrays and 3 polarization elements which are arranged along the scanning direction, each pixel row sub-array comprises N pixel rows which are repeatedly arranged, and N is a positive integer greater than 1;

the 4 pixel row sub-arrays are respectively a first pixel row sub-array, a second pixel sub-row array, a third pixel row sub-array and a fourth pixel row sub-array, and the 3 polarizing elements are respectively a first polarizing element, a second polarizing element and a third polarizing element;

6. The apparatus of claim 1, wherein the full stokes polarization integrating camera comprises N pixel rows arranged repeatedly along a scanning direction, each pixel row comprising 4M pixels, and 3N x M polarizing elements; m, N are all positive integers greater than 1;

7. The apparatus of claim 1, wherein the full stokes polarization integrating camera comprises N pixel rows arranged repeatedly along a scanning direction, each pixel row comprising 4M pixels, and 3M polarizing elements; m, N are all positive integers greater than 1;

8. The defect detecting apparatus according to any one of claims 4 to 7, wherein the first polarizing element comprises a first linear polarizer, the transmission axis of the first linear polarizer is 0 ° or 90 °, the second polarizing element comprises a second linear polarizer, the transmission axis of the second linear polarizer is 45 ° or 135 °, the third polarizing element comprises a quarter-wave plate and a third linear polarizer, the fast axis of the quarter-wave plate and the transmission axis of the third linear polarizer form an angle of 45 ° or 135 °, and the quarter-wave plate is located on the optical path between the third linear polarizer and the pixel row; or,

9. A method of defect detection, comprising:

driving a motion platform to move, and enabling a full Stokes polarization integral camera to complete scanning shooting of a sample to be detected so as to form a full Stokes polarization picture, wherein each pixel point in the full Stokes polarization picture comprises a Stokes vector [ S0, S1, S2 and S3 ];

performing defect detection after filtering out a mirror reflection signal in the data through data processing of the full Stokes polarization picture to obtain defect information of the sample to be detected;

wherein the full Stokes polarization integrating camera comprises a plurality of pixel lines and a plurality of polarization elements for acquiring the signal light beamThe total light intensity I0, the light intensity Ix of the linearly polarized light with the polarization direction of 0 ° or the light intensity Iy of the linearly polarized light with the polarization direction of 90 ° in the signal beam, and the light intensity I of the linearly polarized light with the polarization direction of 45 ° in the signal beam ₄₅ Or linearly polarized light of 135 deg. polarization direction ₁₃₅ Intensity I of left-handed circularly polarized light in the signal beam _L Or the intensity I of right-handed circularly polarized light _R ；

through the data processing to the full stokes polarization picture, carry out defect detection after filtering the mirror surface reflection of light signal in the data, obtain the defect information of the sample that awaits measuring, include:

locating a specular reflection region in the full stokes polarization picture;

acquiring the distribution of the defect area of the sample to be detected according to the filtered light intensity diagram;