Wafer detection system with multi-channel simultaneous scanning function

Abstract

The wafer detection system comprises a first PL channel, a second PL channel, a BF channel and a DF channel which are used for scanning a wafer to be detected at the same time, and the first PL channel and the second PL channel adopt light sources with the same wavelength for illumination and imaging. The BF channel and the DF channel adopt light sources with wavelengths different from those of the first PL channel and the second PL channel for illumination and imaging, a dichroscope assembly is used for integrating light paths, a differential interference imaging mode is adopted for imaging, PL is photoluminescence, BF is a bright field, and DF is a dark field. According to the invention, the BF channel, the DF channel and the PL channel are fused, two PL channels are used, four detection channels are provided, the detection efficiency is high, multiple channels are fused, and the wafer only needs to be scanned once to cope with different types of defects at the same time.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor detection technology, and in particular to a multi-channel simultaneous scanning wafer detection system. Background Art

[0002] Wafers are the basic materials for manufacturing chips. Any defects on their surface and inside will directly affect the function and performance of the chip, and even cause the chip to fail. Therefore, it is very necessary to detect and analyze wafer defects. Wafer defect detection refers to the process of detecting surface and internal defects of wafers during the semiconductor manufacturing process.

[0003] Wafer defect detection has been pursuing higher resolution, better contrast and faster detection speed. In the process of wafer defect detection, due to the different imaging characteristics of different defects, the imaging effects in different detection channels are different. In order to meet the detection of different defects, multi-channel imaging is often required, such as bright field BF imaging, dark field DF imaging, and photoluminescence (PL) imaging. By comparing the imaging differences under different channels, the defect type on the wafer can be determined.

[0004] The existing wafer defect detection technology based on multi-channel imaging cannot distinguish which channel the signal comes from during detection because the light signals of different channels interfere with each other. It is impossible to scan three channels (bright field BF (including differential interference), dark field DF, PL) simultaneously. Multiple scans consume a lot of detection time. For example, the detection time of a wafer with a diameter of 150mm takes about 12 minutes, which is not conducive to industrial production. If multi-channel simultaneous scanning is forced, due to the different intensities of different light signals, simultaneous scanning means the same or close exposure time. Under the same light source intensity, the PL signal is the weakest and it is easy to fail to detect the signal.

[0005] In addition, in existing wafer defect detection technology, the PL channel can often only use one filter at a time. Since the causes of different defects in the wafer are different, the fluorescence bands of the defects are also different, and different defects under the PL channel cannot be detected at the same time. Summary of the invention

[0006] In view of the shortcomings of the prior art mentioned above, the object of the present invention is to provide a multi-channel simultaneous scanning wafer inspection system, which is used to solve the problems that the existing multi-channel imaging wafer defect detection technology cannot achieve three-channel simultaneous scanning at the same time, multiple scans waste detection time and cannot simultaneously detect different defects under the PL channel.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention provides a multi-channel simultaneous scanning wafer inspection system, including a first PL channel, a second PL channel, a BF channel and a DF channel for simultaneously scanning the wafer to be inspected, the first PL channel and the second PL channel use a light source of the same wavelength for illumination and imaging, the BF channel and the DF channel use a light source of a different wavelength from the first PL channel and the second PL channel for illumination and imaging, and a dichroic mirror assembly is used to integrate the optical path, and the imaging uses differential interference imaging, wherein PL is photoluminescence, BF is bright field, and DF is dark field.

[0008] In the above technical solution of the present application, the four channels correspond to four cameras respectively, the first PL channel and the second PL channel use a light source of the same wavelength for illumination and imaging, and the BF channel and the DF channel use a light source of a different wavelength from the first PL channel and the second PL channel for illumination and imaging, and the channels are isolated from each other without interfering with each other, so as to achieve simultaneous scanning, and the detection camera or detector detects the corresponding wavelength. The present invention integrates the BF (including differential interference), DF, and PL channels, and uses two PL channels, a total of four detection channels, which can simultaneously deal with different types of defects. Based on the differential interference imaging method, the present application can magnify the height difference of small defects and make scratches, pits, bumps, etc. produce a relief feeling. Through the above method, it can be realized that 4 channels receive different signals and scan simultaneously. Under the commonly used 10x objective lens, the detection time of a wafer with a diameter of 150mm only takes 4 minutes, which greatly reduces the detection time. According to different detection accuracy requirements, various magnification objective lenses can be selected, which improves industrial production efficiency and promotes the progress of the domestic semiconductor industry.

[0009] Preferably, the multi-channel simultaneous scanning wafer detection system further comprises a focusing optical path, and the focusing optical path is arranged on the first PL channel, the second PL channel and the DF channel. The focusing optical path is used to ensure that each position can be clearly focused.

[0010] Preferably, an ultraviolet light source is provided on the first PL channel and the second PL channel, a laser focus sensor is provided on the focus optical path, a BF light source is provided on the BF channel, and a DF light source is provided on the DF channel.

[0011] Preferably, the ultraviolet light source is used to emit light with a wavelength of 310-365 nm. The ultraviolet light source can be a laser or another type of luminous object, such as a mercury xenon lamp.

[0012] More preferably, the angle between the emitted light of the ultraviolet light source and the horizontal plane of the wafer to be inspected is 30-60°.

[0013] Preferably, the laser focus sensor includes a laser focus light source and a receiver, and the laser focus light source is used to emit light with a wavelength of 640-700 nm. The laser focus sensor is added to the multi-channel simultaneous scanning wafer detection system of the present application, so that wafers with different thickness differences and different warpages can maintain a real-time clear state during the detection process.

[0014] Preferably, the BF light source is used to emit light with a wavelength of 500-620 nm, and the BF light source can be an LED or another similar light-emitting object, such as a laser, a mercury-xenon lamp, or a halogen lamp.

[0015] Preferably, the DF light source is used to emit light of 400-460 nm, and the DF light source can be an LED ring light source or another similar light source, such as a laser or a mercury xenon lamp.

[0016] More preferably, the angle between the emitted light of the DF light source and the horizontal plane of the wafer to be inspected is 30-60°.

[0017] By reducing the wavelength range and light source power of the strong signal channel, weakening the light source intensity of the strong signal channel, and enhancing the detector capability of the weak signal channel, the signal detection capability is balanced and the same exposure time scanning is achieved. The BF channel and DF channel use a single-band light source to weaken the detected signal. The light source of the first PL channel and the second PL channel uses a scientific research-level camera to achieve single-photon level signal detection.

[0018] Preferably, the dichroic mirror assembly includes a dichroic mirror A, a dichroic mirror B, a dichroic mirror C and a dichroic mirror D. The dichroic mirror A and the dichroic mirror D are arranged in sequence on the first PL channel and the second PL channel along the incident direction of the ultraviolet light source, the dichroic mirror C, the dichroic mirror B and the dichroic mirror A are arranged in sequence on the focusing light path along the incident direction of the laser focusing light source, the dichroic mirror C, the dichroic mirror B and the dichroic mirror A are arranged in sequence on the BF channel along the incident direction of the BF light source, and the dichroic mirror A and the dichroic mirror B are arranged in sequence on the DF channel along the incident direction of the DF light source.

[0019] Preferably, on the first PL channel and the second PL channel, a microscope objective lens and a DIC prism are sequentially provided between the dichroic mirror A and the wafer to be inspected along the incident direction of the ultraviolet light source, the first PL channel is provided on the reflective surface side of the dichroic mirror D, and sequentially includes a first filter, a first PL telecentric tube lens and a first PL camera along the incident direction of the ultraviolet light source, the second PL channel is provided on the transmission surface side of the dichroic mirror D, and sequentially includes a second filter, a second PL telecentric tube lens and a second PL camera along the incident direction of the ultraviolet light source, and the first filter and the second filter have different filtering bands; on the focusing optical path, the laser emitted by the laser focusing light source passes through the dichroic mirror C, the dichroic mirror B, the dichroic mirror A, the DIC prism and the microscope objective lens in sequence, hits the surface of the wafer to be inspected and is reflected along the original path, and is received by the receiver again to achieve real-time focusing.

[0020] Since the first PL channel and the second PL channel detect the fluorescence band, which is mixed with signals of various wavelengths, including BF and DF signals, the first filter and the second filter are added in front of the camera or detector to filter out the signals that may cause false detection, thereby realizing multi-channel simultaneous detection. The function of the tube lens is to gather or diverge light and turn it into parallel light or point light.

[0021] Preferably, the first filter is a bandpass filter of 470-490 nm, and the second filter is a bandpass filter of 700-780 nm.

[0022] Preferably, on the BF channel, an incident polarizer, an illumination tube lens and an illumination beam splitter are sequentially arranged between the BF light source and the dichroic mirror C along the incident direction of the light source; an incident slit or an illumination aperture is also arranged between the BF light source and the incident polarizer; the dichroic mirror C is arranged on the reflective surface side of the illumination beam splitter; a transmission polarizer, a BF tube lens and a BF camera are sequentially arranged on the transmission surface side of the illumination beam splitter, and a transmission slit or a transmission aperture is arranged between the BF tube lens and the BF camera.

[0023] More preferably, the illumination beam splitter splits the reflection and transmission of light with a wavelength of 500-620 nm in a 50:50 split.

[0024] Among them, the light emitted by the BF light source passes through the illumination aperture to form a point light source or passes through the incident slit to form a line light source, passes through the incident polarizer to become polarized light, passes through the illumination tube lens to become collimated light, passes through the illumination beam splitter to form reflected light and enters the main illumination light path, passes through the dichroic mirror C, dichroic mirror B, dichroic mirror A, and DIC prism in sequence, and is separated into two beams of light, O light and E light. After passing through the microscope objective, it hits the surface of the wafer to be inspected and is reflected. After passing through the microscope objective and DIC prism again, the two beams of light O and E carrying phase information are re-converged into one beam of light, pass through the dichroic mirror A, dichroic mirror B, dichroic mirror C, and the illumination beam splitter in sequence to form transmitted light, pass through the transmission polarizer, BF tube lens, transmission slit or transmission aperture in sequence, and are captured by the BF camera.

[0025] The role of the incident slit near the BF light source is to generate a line light source for line array camera scanning. The role of the illumination aperture is to generate a point light source for area array camera scanning. The role of the transmission slit or transmission aperture near the BF camera is to block stray light. The incident polarizer, transmission polarizer and DIC prism form a differential interference system.

[0026] DIC principle: The light emitted by the light source becomes linearly polarized light vibrating in the east-west direction after passing through the polarizer. When it enters the DIC prism for the first time, it is divided into ordinary light (o light) and extraordinary light (e light). The two beams of light are slightly separated, and their vibration directions are perpendicular to each other. When the o light and the e light pass through the prism, they have a certain optical path difference T1. When the two beams of light are irradiated onto the sample through the objective lens, they may irradiate on different surface states. The wavefronts of the two beams of light contact the uneven surface, cracks, micropores, depressions, grain boundaries, etc. on the sample, which will produce different reflections. In addition, the phase change of the light wave caused by the difference in the refractive index of light on different physical phases will produce a new additional optical path difference T0. When the two beams of light are reflected by the sample surface, they pass through the objective lens and enter the DIC prism for the second time, and the wavefronts produce a new optical path difference T2 and merge. However, the two beams of light are still linearly polarized lights perpendicular to each other, and no interference occurs. Before entering the analyzer, the total optical path difference Ttotal = T1+T0+T2. Only wavefronts that meet the optical path difference condition Ttotal = (2k+1)λ / 2, where (k=0, 1, 2, etc.) can pass through the analyzer. In other words, after the linearly polarized light passes through the DIC prism twice, only those wavefronts whose total optical path difference is equal to an odd multiple of half the wavelength of the light source light wave reflected by the sample can meet the interference condition and pass through the analyzer to interfere.

[0027] Preferably, on the DF channel, the DF light source is arranged between the microscope objective and the wafer to be inspected, and a DF tube lens and a DF camera are sequentially arranged on the reflective surface side of the dichroic mirror B, wherein after the light emitted by the DF light source hits the surface of the wafer to be inspected, the scattered signal enters the microscope objective, and passes through the DIC prism, dichroic mirror A, dichroic mirror B, and DF tube lens in sequence, and is captured by the DF camera.

[0028] More preferably, the dichroic mirror A reflects light with wavelengths of 370 to 460 nm and 500 to 700 nm among light with wavelengths of 370 to 800 nm, and transmits light with other wavelengths.

[0029] More preferably, the dichroic mirror B transmits light with a wavelength of 500-700 nm, and reflects light with a wavelength of 400-460 nm.

[0030] More preferably, the dichroic mirror C transmits light with a wavelength of 500-620 nm, and reflects light with a wavelength of 640-700 nm.

[0031] More preferably, the dichroic mirror D reflects light with a wavelength of 370-700 nm, and transmits light with a wavelength of 700-800 nm.

[0032] As described above, the multi-channel simultaneous scanning wafer inspection system of the present invention has the following beneficial effects: (1) The BF (including differential interference), DF, and PL channels are integrated, and two PL channels are used, for a total of four detection channels. The detection efficiency is high, and with multi-channel integration, the wafer only needs to be scanned once, and different types of defects can be dealt with at the same time; (2) This application is based on differential interference imaging, which can magnify the height difference of small defects, so that scratches, pits, convex points, etc. have a sense of relief, with a strong 3D sense and good clarity. It is equipped with a real-time focusing system to ensure that every position can be clearly focused; (3) The wafer inspection system with multi-channel simultaneous scanning of the present application can realize four channels receiving different signals and scanning simultaneously. Under the commonly used 10x objective lens, the inspection time for a wafer with a diameter of 150 mm only takes 4 minutes, which greatly reduces the inspection time. According to different inspection accuracy requirements, various magnification objective lenses can be selected, which improves industrial production efficiency and promotes the progress of the domestic semiconductor industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram showing the structure of a wafer inspection system with multi-channel simultaneous scanning.

[0034] Explanation of the accompanying drawings: UV light source 1, microscope objective 11, DIC prism 12, first filter 13, first PL telecentric tube lens 14, first PL camera 15, second filter 16, second PL telecentric tube lens 17, second PL camera 18, laser focus sensor 2, BF light source 3, incident polarizer 31, illumination tube lens 32, illumination beam splitter 33, incident slit 34, transmission polarizer 35, BF tube lens 36, BF camera 37, transmission slit 38, DF light source 4, DF tube lens 41, DF camera 42, dichroic mirror A, dichroic mirror B, dichroic mirror C, dichroic mirror D, wafer to be inspected 5. DETAILED DESCRIPTION

[0035] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0037] Unless otherwise clearly specified and limited, the terms "connection", "fixation" and "setting" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a connection between two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] Example 1 like Figure 1 As shown, an embodiment of the present application provides a multi-channel simultaneous scanning wafer inspection system, including a first PL channel, a second PL channel, a BF channel and a DF channel for simultaneously scanning the wafer to be inspected, the first PL channel and the second PL channel use a light source of the same wavelength for illumination and imaging, the BF channel and the DF channel use a light source of a different wavelength from the first PL channel and the second PL channel for illumination and imaging, and a dichroic mirror assembly is used to integrate the optical path, and the imaging uses differential interference imaging, wherein PL is photoluminescence, BF is bright field, and DF is dark field.

[0039] The dichroic mirror assembly includes a dichroic mirror A, a dichroic mirror B, a dichroic mirror C and a dichroic mirror D. The first PL channel and the second PL channel are provided with an ultraviolet light source 1 for emitting light with a wavelength of 310-365 nm. The angle between the emitted light of the ultraviolet light source and the horizontal plane of the wafer to be detected is 30-60°. The microscope objective 11, the DIC prism 12, the dichroic mirror A and the dichroic mirror D are sequentially arranged on the first PL channel and the second PL channel along the incident direction of the ultraviolet light source. The first PL channel is arranged at the dichroic mirror D. The second PL channel is arranged on the transmission side of the dichroic mirror D, and includes a second filter 16, a second PL telecentric tube lens 17 and a second PL camera 18 in sequence along the incident direction of the ultraviolet light source. The first filter and the second filter have different filtering bands. The first filter is a bandpass filter of 470-490 nm, and the second filter is a bandpass filter of 700-780 nm.

[0040] A laser focus sensor 2 is provided in the focusing optical path, and the laser focus sensor includes a laser focus light source and a receiver, and the laser focus light source is used to emit light with a wavelength of 640-700 nm. A dichroic mirror C, a dichroic mirror B and a dichroic mirror A are sequentially arranged in the focusing optical path along the incident direction of the laser focus light source. In the focusing optical path, the laser emitted by the laser focus light source passes through the dichroic mirror C, the dichroic mirror B, the dichroic mirror A, the DIC prism and the microscope objective lens in sequence, hits the surface of the wafer to be detected and is reflected along the original path, and is received by the receiver again to achieve real-time focusing.

[0041] The BF channel is provided with a BF light source 3 for emitting light with a wavelength of 500-620nm. An incident slit 34, an incident polarizer 31, an illumination tube lens 32, an illumination beam splitter 33, and a dichroic mirror C, a dichroic mirror B, a dichroic mirror A, a DIC prism and a microscope objective lens are sequentially arranged on the reflection side of the illumination beam splitter along the incident direction of the BF light source. A transmission polarizer 35, a BF tube lens 36, a transmission slit 38 and a BF camera 37 are sequentially arranged on the transmission side of the illumination beam splitter. The illumination beam splitter splits the light with a wavelength of 500-620nm into 50:50 reflection and transmission.

[0042] The DF channel is provided with a DF light source 4 for emitting light of 400-460nm, the angle between the emitted light of the DF light source and the horizontal plane of the wafer to be detected is 30-60°, and the DF light source, microscope objective lens, DIC prism, dichroic mirror A, dichroic mirror B, DF tube lens 41 and DF camera 42 arranged on one side of the reflection surface of the dichroic mirror B are arranged in sequence on the DF channel along the incident direction of the light source. The DF light source uses a ring light source. Among the light with a wavelength of 370-800nm, the dichroic mirror A reflects the light with a wavelength of 370-460nm and 500-700nm, and transmits the light with other wavelengths; the dichroic mirror B transmits the light with a wavelength of 500-620nm, reflects the light with a wavelength of 400-460nm, and transmits the light with a wavelength of 640-700nm; the dichroic mirror C transmits the light with a wavelength of 500-620nm, and reflects the light with a wavelength of 640-700nm; the dichroic mirror D reflects the light with a wavelength of 370-700nm, and transmits the light with a wavelength of 700-800nm.

[0043] In this embodiment, the first PL channel, the second PL channel, the BF channel and the DF channel use light sources of different wavelengths respectively, and the channels are isolated from each other without interfering with each other, so as to achieve simultaneous scanning, and the detection camera or detector detects the corresponding wavelength.

[0044] The optical principles of the first PL channel and the second PL channel are as follows: The ultraviolet light source 1 emits light with a wavelength of 310-365nm. After hitting the surface of the wafer 5 to be detected, it excites a fluorescence signal with a wavelength of 370-800nm, and passes through the microscope objective 11, DIC prism 12, dichroic mirror A, and dichroic mirror D. The light with a wavelength of 370-700nm is reflected, and the light with a wavelength of 700-800nm ​​is transmitted. The reflected light passes through the first filter 13 and the first PL telecentric tube lens, and is captured by the first PL camera. The transmitted light passes through the second filter 16 and the second PL telecentric tube lens 17, and is captured by the second PL camera.

[0045] The optical principle of the BF channel is as follows: The light emitted by the BF light source forms a line light source through the incident slit, becomes polarized light through the incident polarizer, becomes collimated light through the illumination tube lens, forms reflected light through the illumination beam splitter and enters the main illumination light path, passes through dichroic mirror C, dichroic mirror B, dichroic mirror A, and DIC prism in sequence, and is separated into two beams of light, O light and E light. After passing through the microscope objective, it hits the surface of the wafer to be inspected and is reflected. After passing through the microscope objective and DIC prism again, the two beams of light O and E carrying phase information are re-converged into one beam of light, pass through dichroic mirror A, dichroic mirror B, dichroic mirror C, and the illumination beam splitter in sequence, and are captured by the BF camera after passing through the transmission polarizer, BF tube lens, and transmission slit in sequence.

[0046] The optical principle of the focusing light path is as follows: The laser emitted by the laser focusing light source passes through dichroic mirror C, dichroic mirror B, dichroic mirror A, DIC prism and microscope objective lens in sequence, hits the surface of the wafer to be inspected and reflects along the original path, and is received by the receiver again to achieve real-time focusing.

[0047] The optical principle of the DF channel is as follows: After the light with a wavelength of 400~460nm emitted by the DF light source hits the surface of the wafer to be inspected, the scattered signal enters the microscope objective lens, and passes through the DIC prism, dichroic mirror A, dichroic mirror B, and DF tube lens in sequence, and is captured by the DF camera.

[0048] Example 2 The difference between Example 2 and Example 1 is that, on the BF channel, the incident slit between the BF light source and the incident polarizer is replaced by an incident aperture, and the transmission slit between the BF tube lens and the BF camera is replaced by a transmission aperture, and the remaining components and connection relationships are exactly the same as those in Example 1.

[0049] The optical principle of the BF channel in this embodiment is as follows: The light emitted by the BF light source passes through the incident aperture to form a point light source, passes through the incident polarizer to become polarized light, passes through the illumination tube lens to become collimated light, passes through the illumination beam splitter to form reflected light and enters the main illumination light path, passes through the dichroic mirror C, dichroic mirror B, dichroic mirror A, and DIC prism in sequence, and is separated into two beams of light, O light and E light. After passing through the microscope objective, it hits the surface of the wafer to be inspected and is reflected. After passing through the microscope objective and DIC prism again, the two beams of light O and E carrying phase information are re-converged into one beam of light, pass through the dichroic mirror A, dichroic mirror B, dichroic mirror C, and the illumination beam splitter in sequence to form transmitted light, pass through the transmission polarizer, BF tube lens, and transmission aperture in sequence, and are captured by the BF camera.

[0050] In summary, the present invention integrates BF (including differential interference), DF, and PL channels, and uses two PL channels, a total of four detection channels, with high detection efficiency, multi-channel fusion, and the wafer only needs to be scanned once, and different types of defects can be dealt with at the same time; based on the differential interference imaging method, the height difference of small defects can be magnified, so that scratches, pits, bumps, etc. have a sense of relief, a strong sense of 3D, good clarity, and equipped with a real-time focusing system to ensure that each position can be focused clearly; the wafer detection system using the multi-channel simultaneous scanning of the present application can realize four channels to receive different signals and scan at the same time. Under the commonly used 10x objective lens, the detection time of a wafer with a diameter of 150mm only takes 4 minutes, which greatly reduces the detection time. According to different detection accuracy requirements, various magnification objective lenses can be selected, which improves industrial production efficiency and promotes the progress of the domestic semiconductor industry. Therefore, the present invention effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0051] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A wafer inspection system with multi-channel simultaneous scanning, characterized in that: The method comprises a first PL channel, a second PL channel, a BF channel and a DF channel for simultaneously scanning a wafer to be inspected, wherein the first PL channel and the second PL channel are illuminated and imaged by a light source of the same wavelength, the BF channel and the DF channel are illuminated and imaged by a light source of a different wavelength from the first PL channel and the second PL channel, and a dichroic mirror assembly is used to integrate the optical path, and the imaging adopts differential interference imaging, wherein PL is photoluminescence, BF is bright field, and DF is dark field.

2. The multi-channel simultaneous scanning wafer inspection system according to claim 1, characterized in that: The multi-channel simultaneous scanning wafer detection system also includes a focusing optical path, and the focusing optical path is arranged on the first PL channel, the second PL channel and the DF channel.

3. The multi-channel simultaneous scanning wafer inspection system according to claim 2, characterized in that: The first PL channel and the second PL channel are provided with an ultraviolet light source (1), the focusing light path is provided with a laser focusing sensor (2), the BF channel is provided with a BF light source (3), and the DF channel is provided with a DF light source (4).

4. The multi-channel simultaneous scanning wafer inspection system according to claim 3, characterized in that: The ultraviolet light source is used to emit light with a wavelength of 310~365nm, and the angle between the emitted light of the ultraviolet light source and the horizontal plane of the wafer to be detected is 30~60°; the laser focus sensor includes a laser focus light source and a receiver, the laser focus light source is used to emit light with a wavelength of 640~700 nm, the BF light source is used to emit light with a wavelength of 500~620nm, and the DF light source is used to emit light with a wavelength of 400~460nm, and the angle between the emitted light of the DF light source and the horizontal plane of the wafer to be detected is 30~60°.

5. The multi-channel simultaneous scanning wafer inspection system according to claim 4, characterized in that: The dichroic mirror assembly includes a dichroic mirror A, a dichroic mirror B, a dichroic mirror C and a dichroic mirror D. The dichroic mirror A and the dichroic mirror D are arranged in sequence along the incident direction of the ultraviolet light source on the first PL channel and the second PL channel, the dichroic mirror C, the dichroic mirror B and the dichroic mirror A are arranged in sequence along the incident direction of the laser focusing light source on the focusing optical path, the dichroic mirror C, the dichroic mirror B and the dichroic mirror A are arranged in sequence along the incident direction of the BF light source on the BF channel, and the dichroic mirror A and the dichroic mirror B are arranged in sequence along the incident direction of the DF light source on the DF channel.

6. The multi-channel simultaneous scanning wafer inspection system according to claim 5, characterized in that: On the first PL channel and the second PL channel, a microscope objective lens (11) and a DIC prism (12) are sequentially arranged between the dichroic mirror A and the wafer to be inspected along the incident direction of the ultraviolet light source; the first PL channel is arranged on the reflection surface side of the dichroic mirror D, and sequentially comprises a first filter (13), a first PL telecentric tube lens (14) and a first PL camera (15) along the incident direction of the ultraviolet light source; the second PL channel is arranged on the transmission surface side of the dichroic mirror D, and sequentially comprises a second filter (16), a second PL telecentric tube lens (17) and a second PL camera (18) along the incident direction of the ultraviolet light source; the first filter and the second filter have different filtering bands; on the focusing optical path, the laser light emitted by the laser focusing light source sequentially passes through the dichroic mirror C, the dichroic mirror B, the dichroic mirror A, the DIC prism and the microscope objective lens, hits the surface of the wafer to be inspected and is reflected along the original path, and is received by the receiver again, so as to achieve real-time focusing.

7. The multi-channel simultaneous scanning wafer inspection system according to claim 6, characterized in that: The first filter is a bandpass filter of 470-490 nm, and the second filter is a bandpass filter of 700-780 nm.

8. The multi-channel simultaneous scanning wafer inspection system according to claim 5, characterized in that: On the BF channel, an incident polarizer (31), an illumination tube lens (32) and an illumination beam splitter (33) are sequentially arranged between the BF light source and the dichroic mirror C along the incident direction of the BF light source; an incident slit (34) or an incident aperture is also arranged between the BF light source and the incident polarizer; the dichroic mirror C is arranged on the reflection surface side of the illumination beam splitter; a transmission polarizer (35), a BF tube lens (36) and a BF camera (37) are sequentially arranged on the transmission surface side of the illumination beam splitter; a transmission slit (38) or a transmission aperture is arranged between the BF tube lens and the BF camera; the illumination beam splitter performs a 50:50 split of reflection and transmission of light with a wavelength of 500-620 nm.

9. The multi-channel simultaneous scanning wafer inspection system according to claim 6, characterized in that: On the DF channel, the DF light source is arranged between the microscope objective lens and the wafer to be inspected, and a DF tube lens (41) and a DF camera (42) are arranged in sequence on the reflection surface side of the dichroic mirror B, wherein after the light emitted by the DF light source hits the surface of the wafer to be inspected, the scattered signal enters the microscope objective lens, passes through the DIC prism, the dichroic mirror A, the dichroic mirror B, and the DF tube lens in sequence, and is captured by the DF camera.

10. The multi-channel simultaneous scanning wafer inspection system according to claim 5, characterized in that: Among the light with a wavelength of 370-800nm, the dichroic mirror A reflects the light with a wavelength of 370-460nm and 500-700nm, and transmits the light with other wavelengths; the dichroic mirror B transmits the light with a wavelength of 500-700nm, and reflects the light with a wavelength of 400-460nm; the dichroic mirror C transmits the light with a wavelength of 500-620nm, and reflects the light with a wavelength of 640-700nm; the dichroic mirror D reflects the light with a wavelength of 370-700nm, and transmits the light with a wavelength of 700-800nm.

Images