Detection system

Abstract

The utility model provides a detection system. The detection system comprises an emitter, a spatial filter and a detection assembly, the detection light is suitable for irradiating the surface of a sample to enable the surface of the sample to emit signal light; the spatial filter is used for dividing the signal light into a plurality of sub-light beams, the plurality of sub-light beams at least comprise a first sub-light beam and a second sub-light beam, and the first sub-light beam and the second sub-light beam are emitted at different angles; the detection assembly comprises a first detector and a second detector, the first detector is suitable for receiving the first sub-beam from the spatial filter to obtain a first to-be-detected target on the surface of the sample, and the second detector is suitable for receiving the second sub-beam from the spatial filter to obtain a second to-be-detected target on the surface of the sample. And the detection system can more comprehensively know the surface information of the sample. The second to-be-detected target on the surface of the sample does not need to be additionally detected, so that the detection efficiency of the sample is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor testing, in particular to a detection system. BACKGROUND

[0002] In the field of semiconductors, after sample preparation, the sample usually needs to be detected. For example, before chip preparation, wafer surface defect detection is needed to reduce the influence of the existence of wafer surface defects on the performance of the chip. The commonly used technology for wafer surface defect detection is optical detection technology, which obtains defect information of the wafer surface by detecting signal light emitted from the wafer surface. However, the above-mentioned optical detection technology can only obtain the defect information of the wafer surface, and cannot obtain other information of the wafer surface, so additional detection is needed, resulting in low detection efficiency. SUMMARY

[0003] In order to improve the detection efficiency of the sample, the present application provides a detection system.

[0004] The present application provides a detection system, which comprises a transmitter, a spatial filter and a detection assembly; the transmitter is used for emitting detection light, and the detection light is suitable for irradiating on a sample surface to make the sample surface emit signal light; the spatial filter is used for dividing the signal light into a plurality of sub-beams, at least including a first sub-beam and a second sub-beam, and the first sub-beam and the second sub-beam are emitted at different angles; the detection assembly comprises a first detector and a second detector, the first detector is suitable for receiving the first sub-beam from the spatial filter, and the second detector is suitable for receiving the second sub-beam from the spatial filter.

[0005] Optionally, the detection system further comprises a collection assembly, the collection assembly comprises an objective lens, the objective lens is used for collecting the signal light and transmitting the signal light to the spatial filter; and the spatial filter is located in a transmission path of the signal light transmitted from the collection assembly to the detection assembly.

[0006] Optionally, the spatial filter is located on a Fourier plane or a conjugate plane of the Fourier plane of the objective lens.

[0007] Optionally, the collection assembly further comprises a first tube lens and a second tube lens, the first tube lens is used for converging the first sub-beam emitted from the spatial filter to the first detector, and the first detector is located on a back focal plane of the first tube lens; and the second tube lens is used for converging the second sub-beam emitted from the spatial filter to the second detector, and the second detector is located on a back focal plane of the second tube lens.

[0008] Optionally, the detection system further comprises a delay component configured to receive the signal light from the objective lens and to image an image plane of the objective lens to the detection component according to the received signal light.

[0009] Optionally, the spatial filter is located between the delay component and the detection component.

[0010] Optionally, the delay component comprises a delay lens and a delay tube lens, the spatial filter is located between the delay lens and the delay tube lens; the delay lens has one focal point coinciding with the image plane of the objective lens, and is configured to collimate the signal light collected from the objective lens; the delay tube lens comprises a first delay tube lens and a second delay tube lens, the first delay tube lens is configured to converge the first sub-beam exiting from the spatial filter to the first detector, and the second delay tube lens is configured to converge the second sub-beam exiting from the spatial filter to the second detector.

[0011] Optionally, the spatial filter is located between the objective lens and the delay component, the delay component comprises a first delay component and a second delay component; the first delay component comprises a first delay lens and a third delay tube lens, the first delay lens is configured to collimate the first sub-beam exiting from the spatial filter, and the third delay tube lens is configured to converge the first sub-beam exiting from the first delay lens to the first detector; the second delay component comprises a second delay lens and a fourth delay tube lens, the second delay lens is configured to collimate the second sub-beam exiting from the spatial filter, and the fourth delay tube lens is configured to converge the second sub-beam exiting from the second delay lens to the second detector.

[0012] Optionally, the detection system comprises a plurality of collection components, and optical axes of the objective lenses of the plurality of collection components are adapted to form different angles with the sample surface.

[0013] Optionally, the objective lens is a curved mirror, the curved mirror has a central axis, and along a direction parallel to the central axis, the curved mirror has a signal light inlet and a signal light outlet arranged oppositely, the signal light inlet is adapted to face the sample, and the signal light outlet faces the spatial filter.

[0014] Optionally, the spatial filter is configured such that a physical quantity of a region for forming the first sub-beam is adjustable, and a physical quantity of a region for forming the second sub-beam is adjustable; the physical quantity comprises one or more of shape, size and position in combination.

[0015] Optionally, the spatial filter comprises a plurality of micromirror devices arranged in an array, the micromirror devices having micromirrors adapted to receive the signal light, wherein the micromirrors for receiving the first sub-beam and the micromirrors for receiving the second sub-beam have different tilting directions.

[0016] Optionally, the tilting direction of the reflecting surface of the micromirror is adjustable; the spatial filter comprises a digital micromirror or a spatial light modulator.

[0017] Optionally, the spatial filter comprises a reflecting device for reflecting the first sub-beam and a light-transmitting hole for transmitting the second sub-beam; or the spatial filter comprises a reflecting device for reflecting the second sub-beam and a light-transmitting hole for transmitting the first sub-beam.

[0018] Optionally, the micromirror device comprises a plurality of first micromirror devices for receiving the first sub-beam or the second sub-beam, the first sub-beam or the second sub-beam having a reflection angle of 0° at the micromirror in the first micromirror device; the detection system further comprises a first beam splitter located in a transmission path of the signal light to the spatial filter, the first beam splitter being adapted to transmit the signal light so that the signal light is received by the spatial filter, and the first beam splitter being further adapted to reflect the first sub-beam or the second sub-beam received by the first micromirror device.

[0019] Optionally, the first sub-beam comprises probe light from a first target to be detected on the sample surface, and the second sub-beam comprises interference light from a second target to be detected on the sample surface; the detection system further comprises a processor for detecting the first target to be detected on the sample surface according to the probe light received by the first probe and detecting the second target to be detected on the sample surface according to the interference light received by the second probe, wherein the first target to be detected comprises a defect, and the second target to be detected comprises roughness.

[0020] The technical solution of the present application has the following advantages:

[0021] The detection system provided in the application, the spatial filter makes the first sub-beam and the second sub-beam exit at different angles, so as to separate the first sub-beam and the second sub-beam in the signal light, the first detector receives the first sub-beam to obtain the first to-be-detected target on the sample surface, and the second detector receives the second sub-beam to obtain the second to-be-detected target on the sample surface, so that the information of the sample surface can be more comprehensively understood. At the same time, the spatial filter separates the first sub-beam and the second sub-beam, which can avoid mutual interference of the two kinds of light in the detection process, so as to improve the detection accuracy of the first to-be-detected target and the second to-be-detected target. Since the second to-be-detected target on the sample surface does not need to be detected additionally, the detection efficiency of the sample is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 A structural schematic diagram of a detection system provided for Embodiment 1 of the present application;

[0024] Figure 2 A structural schematic diagram of a detection system provided for Embodiment 2 of the present application;

[0025] Figure 3 A structural schematic diagram of multiple detection channels provided for Embodiment 3 of the present application;

[0026] Figure 4 A structural schematic diagram of a detection system provided for Embodiment 5 of the present application;

[0027] Figure 5 A structural schematic diagram of a detection system provided for Embodiment 6 of the present application;

[0028] Figure 6 A block diagram of a detection system provided for Embodiment 6 of the present application;

[0029] Figure 7 A block diagram of another detection system provided for Embodiment 6 of the present application.

[0030] Explanation of reference signs:

[0031] 100 - transmitter; 200 - spatial filter; 310 - first detector; 320 - second detector; 410, 410' - objective; 411 - detection channel; 420 - first plane mirror; 510 - first beam splitter; 520 - second beam splitter; 610 - first tube lens; 620 - second tube lens; 700 - polarizer; 800 - first converging lens; 910 - polarization beam splitter; 920 - second plane mirror; 930 - half-wave plate; 940 - second converging lens; 110 - position detecting element; 121 - optical element; 122 - pinhole stop; 131 - controller; 132 - rotating member; 133 - translating member; 140 - delay lens; 141 - first delay lens; 142 - second delay lens; 150 - delay tube lens; 151 - first delay tube lens; 152 - second delay tube lens; 153 - third delay tube lens; 154 - fourth delay tube lens; A - sample. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0033] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0034] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0035] Embodiment 1

[0036] Reference Figure 1The embodiment provides a detection system, which comprises a transmitter 100, a spatial filter 200 and a detection assembly; the transmitter 100 is used for transmitting detection light, the detection light is suitable for irradiating a sample A surface to make the sample surface emit signal light; the spatial filter 200 is used for dividing the signal light into a plurality of sub-beams, at least including a first sub-beam and a second sub-beam, the first sub-beam and the second sub-beam are emitted at different angles; the detection assembly comprises a first detector 310 and a second detector 320, the first detector 310 is suitable for receiving the first sub-beam from the spatial filter 200, and the second detector 320 is suitable for receiving the second sub-beam from the spatial filter 200.

[0037] In the detection system, the spatial filter 200 makes the first sub-beam and the second sub-beam be emitted at different angles, so as to separate the first sub-beam and the second sub-beam in the signal light, the first detector 310 receives the first sub-beam to obtain a first to-be-detected target on the sample surface, and the second detector 320 receives the second sub-beam to obtain a second to-be-detected target on the sample surface, so that the information of the sample surface can be comprehensively understood. Meanwhile, the spatial filter separates the first sub-beam and the second sub-beam, which can avoid mutual interference of the two kinds of light in the detection process, so as to improve the detection precision of the first to-be-detected target and the second to-be-detected target. Since the second to-be-detected target on the sample surface does not need to be detected additionally, the detection efficiency of the sample is improved.

[0038] The detection system further comprises a processor (not shown in the figure), which is used for detecting the first to-be-detected target on the sample surface according to the first sub-beam received by the first detector, and detecting the second to-be-detected target on the sample surface according to the second sub-beam received by the second detector. Specifically, the first sub-beam comprises detection light from a to-be-detected target, and the first to-be-detected target comprises a defect; the second sub-beam comprises interference light from a background, the processor obtains a background image of the to-be-detected target on the sample surface according to the second sub-beam received by the second detector, and obtains the second to-be-detected target on the sample surface according to the background image, and the second to-be-detected target comprises roughness. It should be understood that the first to-be-detected target can also be a solder ball, a circuit line or the like.

[0039] The detection system further comprises a collection assembly, the collection assembly comprises an objective lens 410, the objective lens 410 is used for collecting the signal light and transmitting the signal light to the spatial filter 200; and the spatial filter 200 is located in a transmission path of the signal light transmitted from the collection assembly to the detection assembly. The objective lens 410 in the embodiment can be a lens. Further, the collection assembly can transmit the signal light to the spatial filter 200 in parallel, the objective lens 410 can be a collimating lens, and the signal light obtains parallel light beams after passing through the collimating lens.

[0040] Specifically, the spatial filter 200 is located at a Fourier plane or a conjugate plane of the Fourier plane of the objective lens 410, and the signal light is transmitted to the spatial filter 200 through the objective lens 410. In this embodiment, the Fourier plane is the back focal plane of the objective lens 410.

[0041] Referring to Figure 1 The collection assembly can further include a first tube lens 610 and a second tube lens 620. The first tube lens 610 is configured to converge the first sub-beam exiting the spatial filter 200 to the first detector 310, and the first tube lens 610 is located in a transmission path of the first sub-beam from the spatial filter 200 to the first detector 310, and the first detector 310 is located at a back focal plane of the first tube lens 610. The second tube lens 620 is configured to converge the second sub-beam exiting the spatial filter 200 to the second detector 320, and the second tube lens 620 is located in a transmission path of the second sub-beam from the spatial filter 200 to the second detector 320, and the second detector 320 is located at a back focal plane of the second tube lens 620.

[0042] Referring to Figure 1 The detection system can include a collection assembly, and the collection assembly includes an objective lens 410, and the objective lens 410 corresponds to form a detection channel 411 of the signal light, and the direction of the detection channel 411 is the same as the direction of the optical axis of the objective lens 410, and the direction of the detection channel 411 is perpendicular to the surface of the sample A. It should be understood that the direction of the detection channel 411 can also be arranged obliquely relative to the surface of the sample.

[0043] In this embodiment, the spatial filter 200 can be configured such that the physical quantity of the region for forming the first sub-beam is adjustable, and the physical quantity of the region for forming the second sub-beam is adjustable, and the physical quantity includes one or more combinations of shape, size, and position. For example, the spatial filter 200 can include a plurality of micromirror devices (not shown) arranged in an array, and the micromirror devices have micromirrors adapted to receive the signal light, wherein the reflecting surfaces of the micromirrors for receiving the first sub-beam and the micromirrors for receiving the second sub-beam have different tilt directions, which makes the first sub-beam and the second sub-beam have different reflection angles at the micromirrors, and the reflected light generated at the micromirrors exits in different directions.

[0044] In some embodiments of the present embodiment, the tilting direction of the reflecting surface of the micro-mirror in the spatial filter 200 is fixed. That is, part of the micro-mirror devices in the spatial filter 200 are always used to receive the first sub-beam, part of the micro-mirror devices are always used to receive the second sub-beam, and the exiting direction of the first sub-beam and the second sub-beam is fixed, which is suitable for the detection of the detection position with the same roughness condition.

[0045] The second sub-beam has a certain distribution rule on the cross section of the light path, according to which the second sub-beam can be separated from the signal light. However, the roughness conditions of different samples and different regions of the same sample are different, which leads to the fact that the distribution rule of the second sub-beam on the cross section of the light path is not unique, which requires that the distribution of the micro-mirror devices for receiving the first sub-beam and the second sub-beam in the spatial filter cannot be unique. In some embodiments of the present embodiment, the tilting direction of the reflecting surface of the micro-mirror in the spatial filter is adjustable, so as to adaptively adjust the tilting direction of the reflecting surface of the micro-mirror based on the distribution rule of the second sub-beam on the cross section of the light path, so that the signal light beams irradiated to different positions of the spatial filter 200 are used as the second sub-beam and the detection light, and the spatial filter 200 can filter for different second sub-beam distribution rules. Specifically, the spatial filter includes a digital micro-mirror (DMD) or a spatial light modulator (SLM).

[0046] Further, the micro-mirror device can include a plurality of first micro-mirror devices for receiving the first sub-beam or the second sub-beam, and the reflection angle of the first sub-beam or the second sub-beam at the micro-mirror in the first micro-mirror device is 0°. At this time, the transmission direction of the light rays before and after being reflected by the first micro-mirror device is the same. In order to make the light rays reflected by the first micro-mirror device be received by the corresponding detector, the detection system further includes a first beam splitter 510 located in the transmission path of the signal light to the spatial filter 200, the first beam splitter 510 is adapted to transmit the signal light so that the signal light is received by the spatial filter 200, and the first beam splitter 510 is also adapted to reflect the first sub-beam or the second sub-beam received by the first micro-mirror device, so as to change the transmission direction of the light rays reflected by the first micro-mirror device, so as to be received by the corresponding detector. Specifically, the first beam splitter 510 can be located between the spatial filter 200 and the objective lens 410 in the transmission path of the signal light. Figure 1

[0047] ​Further, the micromirror device can further comprise a second micromirror device, and the first micromirror device and the second micromirror device receive light of different types. That is, the first micromirror device is used to receive the first sub-beam, and the second micromirror device is used to receive the second sub-beam; or, the first micromirror device is used to receive the second sub-beam, and the second micromirror device is used to receive the first sub-beam. The reflection angle of the light irradiated onto the micromirror of the second micromirror device can be 30°-80°, such as 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, or 80°. Specifically, when the reflection angle of the first sub-beam at the micromirror is 0°, the first tube mirror 610 can be located between the first detector 310 and the first beam splitter 510; when the reflection angle of the second sub-beam at the micromirror is 0°, the second tube mirror 620 can be located between the second detector 320 and the first beam splitter 510.

[0048] Referring to Figure 1 , the detection system can further comprise an analyzer 700, which is arranged in the transmission path of the first sub-beam from the spatial filter 200 to the first detector 310 to detect the polarization state of the first sub-beam, and is specifically located between the first beam splitter 510 and the first tube mirror 610. It should be understood that the analyzer 700 can also be located between the first tube mirror 610 and the first detector 310; and can also be arranged in the transmission path of the second sub-beam from the spatial filter to the second detector to detect the polarization state of the second sub-beam, and can be specifically located between the spatial filter and the second tube mirror or between the second tube mirror and the second detector; and can also be arranged in the transmission path of the signal light from the objective lens to the spatial filter to detect the polarization state of the signal light.

[0049] Referring to Figure 1 , the detection system can further comprise a first converging lens 800, which is located on the side of the emitter 100 and in the transmission path of the detection light to the surface of the sample A, so as to converge the detection light on the surface of the sample A.

[0050] Referring to Figure 1The detection light is adapted to perpendicularly illuminate the surface of sample A. The detection system further includes a second beam splitter 520, which is located on the side of the transmitter 100 and on the transmission path of the signal light to the spatial filter 200. The second beam splitter 520 is adapted to reflect the detection light emitted by the transmitter 100 onto the surface of sample A and transmit a portion of the signal light so that the signal light is transmitted to the spatial filter 200. The second beam splitter 520 may be located between sample A and objective lens 410 on the transmission path of the signal light. It should be understood that the second beam splitter 520 may also be located between objective lens 410 and spatial filter 200 on the transmission path of the signal light, such as between objective lens 410 and first beam splitter 510.

[0051] In this embodiment, the sample includes, but is not limited to, a semiconductor element, which may be a semiconductor substrate such as a wafer. It should be understood that the sample may also be glass or a screen.

[0052] In this embodiment, the transmitter 100 can be a semiconductor laser, and the signal light can be scattered light emitted from the sample surface.

[0053] by Figure 1 For example, the transmission direction of light in the detection system is explained as follows: The detection light emitted by the laser is transmitted through the first converging lens 800 to the second beam splitter 520, and is reflected by the second beam splitter 520 onto the surface of sample A; the surface of sample A emits signal light, which has a different polarization direction from the detection light; the signal light passes through the second beam splitter 520 and is transmitted through the objective lens 410 to the first beam splitter 510, and then illuminates the spatial filter 200 through the first beam splitter 510. During this process, the polarization direction of the signal light remains unchanged; the signal light is reflected at the spatial filter 200, and the first sub-beam and the second sub-beam... The beams are emitted at different angles, and the polarization direction of the signal light changes. Based on the different polarization direction of the first sub-beam before reflection, the reflected first sub-beam is transmitted toward the first beam splitter 510 and reflected at the first beam splitter 510. Then, it is transmitted to the first detector 310 through the analyzer 700 and the first tube mirror 610 in sequence. For example, the detection light is polarized in the S plane, the signal light emitted from the surface of sample A is polarized in the P plane, and the first sub-beam after being reflected by the spatial filter 200 is polarized in the S plane. The reflected second sub-beam is transmitted to the second detector 320 through the second tube mirror 620.

[0054] Example 2

[0055] See Figure 2The embodiment provides a detection system, which is different from the detection system provided in the embodiment 1 in that the detection light is adapted to be obliquely incident on the surface of the sample A, and the detection system can not be provided with the second beam splitter 520. Exemplarily, the incident angle of the detection light can be 10-80 degrees, such as 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees or 80 degrees.

[0056] Embodiment 3

[0057] Referring to Figure 3 The embodiment provides a detection system, which is different from the detection system provided in the embodiment 1 in that the detection system can include a plurality of collection assemblies, each of which includes an objective lens 410, and the optical axis of each of the objective lenses 410 is adapted to form an included angle with the surface of the sample A at different angles, that is, a plurality of objective lenses 410 correspond to form a plurality of detection channels 411 at different angles with the sample surface.

[0058] Embodiment 4

[0059] The embodiment provides a detection system, which is different from the detection system provided in the embodiment 1 in that:

[0060] The micromirror device includes a plurality of first micromirror devices, and the first micromirror devices are used for receiving the first sub-beam or the second sub-beam, and the reflection angle of the first sub-beam or the second sub-beam at the micromirror in the first micromirror device is greater than 0°. In order to enable the light reflected by the first micromirror device to be received by the corresponding detector, the corresponding detector can be arranged at a proper position, and therefore the first beam splitter 510 can not be arranged in the detection system.

[0061] Specifically, when the reflection angle of the first sub-beam at the micromirror is greater than 0°, the first tube mirror 610 can be located between the first detector 310 and the spatial filter 200. When the reflection angle of the second sub-beam at the micromirror is less than 0° or greater than 0°, the second tube mirror 620 can be located between the second detector 320 and the spatial filter 200.

[0062] Embodiment 5

[0063] Referring to Figure 4 The embodiment provides a detection system, which is different from the detection system provided in the embodiment 1 in that:

[0064] In the embodiments 1-4, the objective lens 410 and the first tube mirror 610 jointly constitute an imaging unit to image the sample to the first detector 310 according to the received first sub-beam, and the objective lens 410 and the second tube mirror 620 jointly constitute an imaging unit to image the sample to the second detector 320 according to the received second sub-beam; in the embodiment, the objective lens 410 ′For directly imaging the sample to the detection assembly. Here, imaging refers to making a point on the detector correspond one-to-one to a point on the sample surface. A point scan can be considered as imaging of a point.

[0065] The objective 410 ′ The curved mirror has a central axis, and along a direction parallel to the central axis, the curved mirror has oppositely arranged signal light inlets and signal light outlets, the signal light inlets are adapted to face the sample A, and the signal light outlets face the spatial filter 200. The mirror surface of the curved mirror can be coaxial with the normal line of the sample A surface. After the detection light irradiates the sample A surface, the sample A surface generates signal light; the signal light enters the curved mirror through the signal light inlets, is reflected by the curved mirror, and is transmitted to the spatial filter 200 through the signal light outlets. The objective being a curved mirror can collect signal light from different angles of the sample surface without the need to set multiple detection channels. Specifically, the curved mirror can be an ellipsoidal mirror, and the signal light is transmitted to the spatial filter 200 after being reflected by the ellipsoidal mirror.

[0066] The micromirror device includes a plurality of first micromirror devices and a plurality of second micromirror devices (not shown), and the first micromirror devices and the second micromirror devices receive different types of light. That is, the first micromirror devices are used to receive the first sub-beam, and the second micromirror devices are used to receive the second sub-beam; or, the first micromirror devices are used to receive the second sub-beam, and the second micromirror devices are used to receive the first sub-beam. The reflection angle of the first sub-beam or the second sub-beam at the micromirror in the corresponding micromirror device is greater than 0°, and by arranging the corresponding detector at a proper position, the light reflected by the corresponding micromirror device can be received by the corresponding detector, so that the first beam splitter 510 can not be arranged in the detection system.

[0067] In this embodiment, the first detector 310 can be a photomultiplier tube, and the second detector 320 can be a photomultiplier tube.

[0068] Referring to Figure 4 The detection system further includes a first plane mirror 420, the first plane mirror 420 is located close to the signal light outlet, and the first plane mirror 420 is used to reflect the detection light to change the transmission direction of the detection light so that the detection light irradiates the sample A surface. Specifically, the first converging lens 800 is located between the laser and the first plane mirror 420. The first plane mirror 420 can be located on the central axis of the curved mirror.

[0069] Referring to Figure 4The detection system can further comprise an oblique-incident assembly, which comprises a polarizing beam splitter 910, a second planar mirror 920, a half wave plate 930 and a second converging lens 940. The polarizing beam splitter 910 is located between the emitter 100 and the first converging lens 800. After the detection light irradiates the polarizing beam splitter 910, a first polarized component in the detection light transmits through the polarizing beam splitter 910 to irradiate the first planar mirror 420 and then the sample A surface; a second polarized component in the detection light reflects to the second planar mirror 920 and then sequentially passes through the half wave plate 930 and the second converging lens 940 to obliquely irradiate the sample A surface. The second planar mirror 920 is a rotatable mirror, and the second converging lens 940 can be moved along the optical axis direction thereof to adjust the position of the light spot obliquely irradiating the sample surface.

[0070] Referring to Figure 4 The detection system can further comprise a position detection element 110 located at the side of the collection assembly for obtaining the position of the light spot formed by the detection light on the sample A surface. In the process of defect detection by using the second polarized component in the detection light in the oblique-incident manner, the shift of the position of the light spot irradiating the sample surface along the sample thickness direction causes the shift of the defect position detected by the oblique-incident manner along the direction parallel to the sample surface, thereby causing the deviation of the defect position detected by the detection assembly. According to the position of the light spot obtained by the position detection element 110, the rotation angle of the second planar mirror 920 and / or the movement of the second converging lens 940 can be adjusted to adjust the position of the light spot irradiating the sample surface by the second polarized component. The position detection element 110 can be a Quadcell, such as a four-quadrant photodetector.

[0071] Referring to Figure 4 The detection system can further comprise an expansion assembly located between the emitter 100 and the first converging lens 800, for example, located between the emitter 100 and the polarizing beam splitter 910. The expansion assembly can adopt a Kepler-type expansion assembly and a Galileo-type expansion assembly. As shown in Figure 4 The Kepler-type expansion assembly comprises two optical elements 121 with positive focal power arranged oppositely, and the optical element 121 is a lens or a lens group. A pinhole diaphragm 122 can be added at the focal point between the two optical elements 121 to filter out external stray light and intercept a uniform part of the light field energy. The Galileo-type expansion assembly comprises two optical elements 121 arranged oppositely, and the two optical elements 121 have positive focal power and negative focal power, respectively.

[0072] Referring to Figure 4The detection system further comprises a bearing platform and a driving assembly, wherein the driving assembly comprises a controller 131, a rotating member 132 and a translating member 133. The bearing platform is used for bearing the sample A, and the sample surface in the present application refers to the surface of the sample away from the bearing platform; the rotating member 132 is connected with the bearing platform, and the rotating member 132 is used for driving the bearing platform to rotate around the rotation axis of the rotating member 132; the translating member 133 is connected with the rotating member 132, and the translating member 133 is used for driving the rotating member 132 to translate; the controller 131 is used for controlling the rotation time, rotation time length and rotation speed of the rotating member 132; and the controller 131 is further used for controlling the translation time, translation direction and translation distance of the translating member 133. Through the driving assembly, the detection light can scan the whole sample surface in a spiral track, so that the detection assembly obtains the first target to be detected and the second target to be detected at different positions of the sample surface.

[0073] Embodiment 6

[0074] Referring to Figure 5 , the present embodiment provides a detection system, which is different from the detection system provided in Embodiment 5 in that:

[0075] The spatial filter 200 comprises a reflecting device (not shown) and a light-transmitting hole (not shown). The reflecting device is used for reflecting the first sub-beam, and the light-transmitting hole is used for transmitting the second sub-beam. The second sub-beam is transmitted to the second detector 320 through the light-transmitting hole; or, the reflecting device is used for reflecting the second sub-beam, and the light-transmitting hole is used for transmitting the first sub-beam. The first sub-beam is transmitted to the first detector 310 through the light-transmitting hole. Since the positions of the reflecting device and the light-transmitting hole in the spatial filter 200 are fixed, and the inclination direction of the reflecting surface of the reflecting device is fixed, the emission directions of the first sub-beam and the second sub-beam are fixed. The spatial filter 200 is suitable for the detection of detection positions with the same roughness.

[0076] In the present embodiment, the detection system can further comprise a delay assembly, which is used for receiving the signal light passing through the objective lens and imaging the image surface of the objective lens to the detection assembly according to the received signal light. The delay assembly can comprise a delay lens and a delay tube lens. The delay lens is used for collimating the signal light or the sub-beam, and the delay tube lens is used for converging the signal light or the sub-beam from the delay lens.

[0077] Specifically, referring to Figure 5 , the spatial filter 200 can be located between the delay lens 140 and the delay tube lens. One focal point of the delay lens 140 coincides with the image surface of the objective lens 410 ′ , and the delay lens 140 is used for collimating the signal light or the sub-beam from the objective lens 410 ′The collected signal light is collimated; the delay tube mirror comprises a first delay tube mirror 151 and a second delay tube mirror 152, the first detector 310 is located at the back focal plane of the first delay tube mirror 151, and the second detector 320 is located at the back focal plane of the second delay tube mirror 152, the first delay tube mirror 151 is used for converging the first sub-beam emitted from the spatial filter 200 to the first detector 310, and the second delay tube mirror 152 is used for converging the second sub-beam emitted from the spatial filter 200 to the second detector 320.

[0078] It should be understood that, referring to Figure 6 , in the embodiment, the spatial filter 200 can be located between the objective lens 410 ′ and the delay assembly, the delay assembly comprises a first delay assembly and a second delay assembly; the first delay assembly comprises a first delay lens 141 and a third delay tube mirror 153, the first detector 310 is located at the back focal plane of the third delay tube mirror 153, the first delay lens 141 is used for collimating the first sub-beam emitted from the spatial filter 200, and the third delay tube mirror 153 is used for converging the first sub-beam emitted from the first delay lens 141 to the first detector 310; the second delay assembly comprises a second delay lens 142 and a fourth delay tube mirror 154, the second detector 320 is located at the back focal plane of the fourth delay tube mirror 154, the second delay lens 142 is used for collimating the second sub-beam emitted from the spatial filter 200, and the fourth delay tube mirror 154 is used for converging the second sub-beam emitted from the second delay lens 142 to the second detector 320.

[0079] It should be understood that, in the embodiment, the spatial filter can also be located between the delay assembly and the detection assembly. Referring to Figure 7 , the delay assembly comprises a delay lens 140 and a delay tube mirror 150, the spatial filter 200 is located between the delay tube mirror 150 and the first detector 310, and between the delay tube mirror 150 and the second detector 320, one focal point of the delay lens 140 coincides with the image plane of the objective lens 410 ′ , the delay lens 140 is used for collimating the signal light collected from the objective lens 410 ′ , and the delay tube mirror 150 is used for converging the signal light emitted from the delay lens 140 to the spatial filter 200.

[0080] In the embodiment, the polarizer 700 is arranged in the transmission path of the signal light from the objective lens to the spatial filter, and can be arranged between the signal light outlet of the ellipsoidal mirror and the delay lens 140.

[0081] Embodiment 7

[0082] The embodiment provides a detection system, which is different from the detection system provided in Embodiment 6 in that the curved mirror is a parabolic mirror, a main focal point of the parabolic mirror is located on a sample surface, and detection light is adapted to be irradiated on the main focal point of the parabolic mirror, and signal light generated by the sample surface generates a collimated light beam after being reflected by the parabolic mirror, and the collimated light beam is transmitted to a spatial filter.

[0083] In the embodiment, the detection system can further include a delay component, which is used to receive signal light passing through the objective lens and image an image plane of the objective lens to a detection component according to the received signal light. The delay component can include a delay tube mirror, which is used to converge the signal light or the sub-beams.

[0084] Specifically, the spatial filter can be located between the parabolic mirror and the delay tube mirror, the collimated light beam from the parabolic mirror is divided into a plurality of sub-beams through the spatial filter, and the plurality of sub-beams at least include a first sub-beam and a second sub-beam; the delay tube mirror includes a first delay tube mirror and a second delay tube mirror, the first detector is located at a back focal plane of the first delay tube mirror, the second detector is located at a back focal plane of the second delay tube mirror, the first delay tube mirror is used to converge the first sub-beam emitted from the spatial filter to the first detector, and the second delay tube mirror is used to converge the second sub-beam emitted from the spatial filter to the second detector.

[0085] It should be understood that, in the embodiment, the spatial filter can be located between the objective lens and the delay component, the delay component includes a third delay tube mirror and a fourth delay tube mirror, the first detector is located at a back focal plane of the third delay tube mirror, the second detector is located at a back focal plane of the fourth delay tube mirror, the third delay tube mirror is used to converge the first sub-beam emitted from the spatial filter to the first detector, and the fourth delay tube mirror is used to converge the second sub-beam emitted from the spatial filter to the second detector.

[0086] It should be understood that, in the embodiment, the spatial filter can also be located between the delay component and the detection component. The delay component includes a delay tube mirror, the spatial filter is located between the delay tube mirror and the first detector and between the delay tube mirror and the second detector, and the delay tube mirror is used to converge the signal light emitted from the parabolic mirror to the spatial filter.

[0087] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be enumerated and it is impossible to enumerate all the embodiments. The changes or variations derived from the above are still within the protection scope of the present application.

Claims

1. A detection system, characterized in that, The detection system comprises: a transmitter for transmitting detection light, the detection light being adapted to illuminate a sample surface to cause the sample surface to emit signal light; a spatial filter for splitting the signal light into a plurality of sub-beams, the plurality of sub-beams comprising at least a first sub-beam and a second sub-beam, the first sub-beam and the second sub-beam exiting at different angles; a detection assembly comprising a first detector adapted to receive the first sub-beam from the spatial filter and a second detector adapted to receive the second sub-beam from the spatial filter.

2. The detection system of claim 1, wherein, Further comprising: a collection assembly comprising an objective for collecting the signal light and transmitting the signal light to the spatial filter; the spatial filter being located in a transmission path of the signal light from the collection assembly to the detection assembly.

3. The detection system of claim 2, wherein, the spatial filter being located at a Fourier plane or a conjugate plane of the Fourier plane of the objective.

4. The detection system of claim 2, wherein, the collection assembly further comprising: a first tube lens for converging the first sub-beam exiting from the spatial filter to the first detector, the first detector being located at a back focal plane of the first tube lens; a second tube lens for converging the second sub-beam exiting from the spatial filter to the second detector, the second detector being located at a back focal plane of the second tube lens.

5. The detection system of claim 2, wherein, the detection system further comprising: a delay assembly for receiving signal light passing through the objective and imaging an image plane of the objective to the detection assembly based on the received signal light.

6. The detection system of claim 5, wherein, the spatial filter being located between the delay assembly and the detection assembly.

7. The detection system of claim 5, wherein, the delay assembly comprising a delay lens and a delay tube lens, the spatial filter being located between the delay lens and the delay tube lens; one focal point of the delay lens coinciding with the image plane of the objective, the delay lens being used for collimating the signal light collected from the objective; the delay tube lens comprising a first delay tube lens for converging the first sub-beam exiting from the spatial filter to the first detector and a second delay tube lens for converging the second sub-beam exiting from the spatial filter to the second detector.

8. The detection system of claim 5, wherein, the spatial filter being located between the objective and the delay assembly, the delay assembly comprising a first delay assembly and a second delay assembly; the first delay assembly comprising a first delay lens for collimating the first sub-beam exiting from the spatial filter and a third delay tube lens for converging the first sub-beam exiting from the first delay lens to the first detector; the second delay assembly comprising a second delay lens for collimating the second sub-beam exiting from the spatial filter and a fourth delay tube lens for converging the second sub-beam exiting from the second delay lens to the second detector.

9. The detection system according to any one of claims 2-8, characterized in that, The detection system comprises a plurality of collection assemblies, optical axes of objectives in the plurality of collection assemblies are adapted to form different angles with the sample surface.

10. The detection system according to any one of claims 2-8, characterized in that, The objective is a curved mirror, the curved mirror has a central axis, and along a direction parallel to the central axis, the curved mirror has oppositely arranged signal light inlets and signal light outlets, the signal light inlets are adapted to face the sample, and the signal light outlets face the spatial filter.

11. The detection system of claim 1, wherein, The spatial filter is configured such that a physical quantity of a region for forming the first sub-beam is adjustable, and a physical quantity of a region for forming the second sub-beam is adjustable; the physical quantity includes one or more combinations of shape, size, and position.

12. The detection system of claim 11, wherein, The spatial filter comprises a plurality of micromirror devices arranged in an array, the micromirror devices have micromirrors adapted to receive the signal light, wherein the reflecting surfaces of the micromirrors for receiving the first sub-beam and the micromirrors for receiving the second sub-beam have different tilting directions.

13. The detection system of claim 12, wherein, The tilting direction of the reflecting surface of the micromirror is adjustable; the spatial filter comprises a digital micromirror or a spatial light modulator.

14. The detection system of claim 1, wherein, The spatial filter comprises a reflecting device for reflecting the first sub-beam and a light-transmitting hole for transmitting the second sub-beam; or the reflecting device is for reflecting the second sub-beam, and the light-transmitting hole is for transmitting the first sub-beam.

15. The detection system of claim 12 or 13, wherein, The micromirror device comprises a plurality of first micromirror devices for receiving the first sub-beam or the second sub-beam, and the reflection angle of the first sub-beam or the second sub-beam at the micromirror in the first micromirror device is 0°; The detection system further comprises a first beam splitter in a transmission path of the signal light transmitted to the spatial filter, the first beam splitter is adapted to transmit the signal light so that the signal light is received by the spatial filter, and the first beam splitter is further adapted to reflect the first sub-beam or the second sub-beam received by the first micromirror device.

16. The detection system according to any one of claims 1-8, characterized in that, The first sub-beam comprises probe light from a target to be detected; and the second sub-beam comprises interference light from a background. The detection system further comprises: a processor for detecting a first target to be detected on a sample surface according to probe light received by the first probe and detecting a second target to be detected on the sample surface according to interference light received by the second probe, wherein the first target to be detected includes a defect, and the second target to be detected includes roughness.

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