Wafer inspection device and wafer inspection method

Abstract

The application discloses a wafer detection device and a wafer detection method. The wafer detection device comprises: a carrier for loading a wafer and linearly moving, the wafer having a substrate and a film layer covering the substrate; a first substrate imaging system comprising a first light source module and a first detection module, the first light source module being used for emitting illumination light to the surface of the wafer, and the first detection module being used for collecting the substrate image of the wafer; a first film layer imaging system comprising a second light source module and a second detection module, the second light source module being used for emitting illumination light to the surface of the wafer, and the second detection module being used for collecting the film layer image of the wafer; and an analysis module electrically connected with the first substrate imaging system and the first film layer imaging system, respectively, and used for analyzing the substrate image to obtain the substrate defect information of the wafer and analyzing the film layer image to obtain the film layer defect information of the wafer. The wafer detection device can simultaneously detect the defects of the substrate and the surface film layer of the wafer, and the wafer detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer detection, in particular to a wafer detection device and a wafer detection method. BACKGROUND

[0002] As a core basic material in the field of semiconductors and optoelectronics, the processing quality of a wafer directly affects the performance of the final product. The complete process from wafer to chip includes key processes such as oxidation, lithography, grinding, etching, packaging, and testing. There are potential processing defects in multiple links that affect yield. On the one hand, during wafer manufacturing, defects on the wafer surface are often caused by contamination such as dust, dirt, scratches, and particulate foreign matter, and process defects, resulting in damage; on the other hand, in the grinding and dicing processes, protective films need to be attached to the front or back surface of the wafer for protection, which may cause bubble defects due to poor adhesion, and the film layer itself may also have structural abnormalities such as protrusions and pits. These defects on the wafer substrate surface and the film layer not only reduce the processing accuracy of the current process, but also affect the subsequent process, ultimately seriously affecting chip yield and product reliability. Therefore, it is particularly important to detect defects on the wafer surface and the film layer.

[0003] Currently, existing wafer detection mainly includes bright field detection, dark field detection, or a combination of bright field and dark field detection methods. For bright field imaging, due to the transparency of the film layer, its reflectivity differs greatly from that of the wafer substrate, resulting in that the bright field imaging method can only capture the reflection signal of the wafer substrate surface, and the film layer with low reflectivity cannot achieve bright field imaging. For dark field imaging, due to the difference in physical properties, the scattering signals formed by the same dark field light source on the wafer substrate and the film layer are different, which makes it impossible to accurately capture the film layer defect information. Therefore, in order to achieve detection of the film layer, it is necessary to increase a set of detection devices and a detection process, which greatly reduces the efficiency of wafer detection. SUMMARY

[0004] Therefore, the present application provides a wafer detection device and a wafer detection method to solve the problem that existing wafer detection cannot achieve synchronous detection of the wafer substrate and the film layer.

[0005] To solve the above technical problems, one technical scheme adopted by the present application is to provide a wafer detection device, which comprises: a carrier for loading a wafer and performing linear movement, the wafer having a substrate and a film layer covering the substrate; a first substrate imaging system comprising a first light source module and a first detection module, the first light source module being configured to emit illumination light to the surface of the wafer, and the first detection module being configured to acquire a substrate image of the wafer; a first film layer imaging system comprising a second light source module and a second detection module, the second light source module being configured to emit illumination light to the surface of the wafer, and the second detection module being configured to acquire a film layer image of the wafer; and an analysis module electrically connected to the first substrate imaging system and the first film layer imaging system, and configured to analyze the substrate image to obtain substrate defect information of the wafer, and analyze the film layer image to obtain film layer defect information of the wafer.

[0006] As a further improvement of the present application, the first light source module comprises a first bright field irradiation unit and a first dark field irradiation unit, the first bright field irradiation unit emits first illumination light to the surface of the wafer at a first incident angle, the first dark field irradiation unit emits second illumination light to the surface of the wafer at a second incident angle, and the first detection module is configured to acquire a bright field reflection image or a dark field scattering image of the substrate of the wafer; the second light source module comprises a second dark field irradiation unit, the second dark field irradiation unit emits third illumination light to the surface of the wafer at a third incident angle, and the second detection module is configured to acquire a film layer scattering image of the film layer on the surface of the wafer.

[0007] As a further improvement of the present application, the first bright field irradiation unit and the first dark field irradiation unit each have a corresponding adjustment device, which is configured to adjust at least one of the pitch angle, the horizontal position and the vertical position so that the first incident angle is within a first preset angle range and the second incident angle is within a second preset angle range, and the first preset angle range is smaller than the second preset angle range.

[0008] As a further improvement of the present application, the first detection module comprises a first imaging lens, a first linear array camera and a first camera adjustment device, the first imaging lens is configured to receive reflected light of the first illumination light on the substrate surface of the wafer or scattered light of the second illumination light on the substrate surface of the wafer, and transmit the received light beam to the first linear array camera, and the first camera adjustment device is configured to adjust at least one of the pitch angle, the horizontal position and the vertical position of the first imaging lens so that the optical axis of the first imaging lens is symmetrical to the optical axis of the first bright field irradiation unit about the normal of the surface of the wafer.

[0009] As a further improvement of the present application, the second dark field irradiation unit has a corresponding adjustment device, which is configured to adjust at least one of the pitch angle, the horizontal position and the vertical position so that the third incident angle is within a third preset angle range, and the third preset angle range is greater than the second preset angle range.

[0010] As a further improvement of the present application, the second detection module comprises a second imaging lens, a second linear array camera and a second camera adjusting device, the second imaging lens is used for receiving the scattered light of the third illumination light on the film layer of the wafer and transmitting the received light beam to the second linear array camera, and the second camera adjusting device is used for adjusting the pitch angle of the second imaging lens.

[0011] As a further improvement of the present application, the first light source module is used for emitting the illumination light of the first preset wavelength which can easily penetrate the film layer to reach the substrate, and the second light source module is used for emitting the illumination light of the second preset wavelength which can easily reflect or scatter on the surface of the film layer.

[0012] As a further improvement of the present application, the carrier comprises a bearing part and a driving part, the bearing part is arranged on the driving part, the bearing part is used for bearing and limiting the wafer, and the driving part is used for driving the bearing part to move to drive the wafer to linearly move.

[0013] As a further improvement of the present application, it further comprises a second substrate imaging system and a second film layer imaging system; the first substrate imaging system and the first film layer imaging system are arranged on one side of the wafer, and the second substrate imaging system and the second film layer imaging system are arranged on the other side of the wafer; the first light source module and the second light source module are both used for emitting the illumination light to the first to-be-detected position on the front surface of the wafer, the first detection module is used for collecting the substrate image at the first to-be-detected position, and the second detection module is used for collecting the film layer image at the first to-be-detected position; the second substrate imaging system comprises a third light source module and a third detection module, the third light source module is used for emitting the illumination light to the second to-be-detected position on the back surface of the wafer, and the third detection module is used for collecting the substrate image at the second to-be-detected position, the projection positions of the first to-be-detected position and the second to-be-detected position on the front surface or the back surface of the wafer are staggered with each other; the second film layer imaging system comprises a fourth light source module and a fourth detection module, the fourth light source module is used for emitting the illumination light to the second to-be-detected position, and the fourth detection module is used for collecting the film layer image at the second to-be-detected position; the analysis module is further electrically connected with the second substrate imaging system and the second film layer imaging system, and the analysis module is further used for analyzing the substrate images and the film layer images of the first to-be-detected position and the second to-be-detected position to obtain the defect information of the substrate and the film layer of the wafer.

[0014] To solve the above technical problems, another technical solution adopted by the present application is to provide a wafer detection method applied to one of the wafer detection devices; the method comprises the following steps: loading the wafer to be detected to the carrier; controlling the first light source module and the second light source module to be turned on, the first light source module and the second light source module emit the illumination light to the surface of the wafer, the carrier drives the wafer to linearly move, the first detection module obtains the substrate image of the wafer, and the second detection module obtains the film layer image of the wafer; and the analysis module analyzes the substrate image to obtain the substrate defect information of the wafer and analyzes the film layer image to obtain the film layer defect information of the wafer.

[0015] As a further improvement of the present application, the first light source module comprises a first bright field illumination unit and a first dark field illumination unit, and the second light source module comprises a second dark field illumination unit; the first light source module and the second light source module are controlled to be turned on, the first light source module and the second light source module emit illumination light to the wafer surface, the wafer is driven to perform linear motion by the stage, the first detection module acquires the substrate image of the wafer, and the second detection module acquires the film layer image of the wafer; the first bright field illumination unit is turned on and emits first illumination light to the wafer surface, and the second dark field illumination unit is turned on and emits third illumination light to the wafer surface; the wafer is driven to perform linear motion by the stage, the first detection module acquires the bright field reflection image of the wafer substrate, and the second detection module acquires the film layer scattering image of the wafer film layer; the first bright field illumination unit and the second dark field illumination unit are turned off, the first dark field illumination unit is turned on and emits second illumination light to the wafer surface; the wafer is driven to move from the dark field imaging position to the bright field imaging position by the stage, and the first detection module acquires the dark field scattering image of the wafer substrate.

[0016] As a further improvement of the present application, the first bright field illumination unit, the first dark field illumination unit and the second dark field illumination unit each have a corresponding adjusting device; after the first bright field illumination unit is turned on and emits first illumination light to the wafer surface, and the second dark field illumination unit is turned on and emits third illumination light to the wafer surface, the adjusting device further adjusts at least one of the pitch angle, the horizontal position and the vertical position of the first bright field illumination unit, so that the first incident angle of the first illumination light is within a first preset angle range; the adjusting device further adjusts at least one of the pitch angle, the horizontal position and the vertical position of the second dark field illumination unit, so that the third incident angle of the third illumination light is within a third preset angle range; after the first dark field illumination unit is turned on and emits second illumination light to the wafer surface, the adjusting device further adjusts at least one of the pitch angle, the horizontal position and the vertical position of the first dark field illumination unit, so that the second incident angle of the second illumination light is within a second preset angle range; the first preset angle range is smaller than the second preset angle range, and the third preset angle range is larger than the second preset angle range.

[0017] As a further improvement of the present application, the first light source module and the second light source module emit illumination light to the wafer surface, including: the first light source module emits illumination light of a first preset wavelength that can easily penetrate the film layer to reach the substrate to the wafer surface, and the second light source module emits illumination light of a second preset wavelength that can easily reflect or scatter on the surface of the film layer to the wafer surface.

[0018] The present application has the following beneficial effects:

[0019] The wafer detection device of the present application is provided with two groups of optical imaging systems of the first substrate imaging system and the first film layer imaging system, and the wafer substrate imaging and the film layer imaging are synchronously realized by the first detection module and the second detection module without interference between the two groups of optical imaging systems, so that the synchronous detection of the wafer substrate and the film layer is realized, and the efficiency of wafer detection is greatly improved. Moreover, the first bright field irradiation unit and the first dark field irradiation unit with different incident angles are arranged, the bright field detection and the dark field detection of the wafer surface are realized, the second dark field irradiation unit with another incident angle is arranged, the dark field detection of the film layer is realized, the multi-channel optical signal separation and the multi-camera cooperative imaging are realized, the imaging interference of the wafer high-reflective substrate to the low-reflective film layer is solved, the synchronous detection of the wafer surface defect and the film layer defect is realized, the wafer defect detection efficiency is improved, and the equipment cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of one embodiment of the wafer detection device of the present application;

[0021] Figure 2 is a schematic diagram of the electrical connection relationship of another embodiment of the wafer detection device of the present application;

[0022] Figure 3 is a structural schematic diagram of another embodiment of the wafer detection device of the present application;

[0023] Figure 4 is a schematic diagram of the electrical connection relationship of another embodiment of the wafer detection device of the present application;

[0024] Figure 5 is a flow schematic diagram of one embodiment of the wafer detection method of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0026] The terms "first", "second", "third", etc. are used only for descriptive purposes and do not connote or imply relative importance or a quantity of the indicated technical features. Thus, features with "first", "second", or "third" designation can include at least one of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality" is at least two, for example, two, three, etc., unless otherwise specifically defined. All directional references, such as up, down, left, right, front, back, etc., used in the description of the present application are only used for convenience and do not imply or create any limitations on the scope of the present application. In addition, the terms "comprise", "comprising", "have", "having", "include", "including", and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a list of steps or units is not limited to the listed steps or units, but can optionally further include other steps or units not expressly listed or inherent to such process, method, system, product, or apparatus.

[0027] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be combined with any of the other embodiments.

[0028] Figure 1 is a structural schematic diagram of a wafer detection device according to an embodiment of the present application. As shown in Figure 1 , the wafer detection device comprises a stage 1, a first substrate imaging system 2, a first film layer imaging system 3, and an analysis module 4 (for details, please refer to Figure 2 ).

[0029] The stage 1 is used to load a wafer and perform linear movement, and the wafer has a substrate and a film layer covering the substrate.

[0030] The first substrate imaging system 2 comprises a first light source module 21 and a first detection module 22, the first light source module 21 is used for emitting illumination light to the wafer surface, and the first detection module 22 is used for collecting the substrate image of the wafer. Specifically, the first substrate imaging system 2 comprises the first light source module 21 and the first detection module 22, the first light source module 21 comprises one light source or two light sources. If it is one light source, the light source can irradiate the wafer surface at a small incident angle (relative to the normal line), and the reflection light signal of the wafer surface is collected by the first detection module 22 for detection, so as to realize bright field detection; or the light source can irradiate the wafer surface at a large incident angle (relative to the normal line), and the scattering light signal of the wafer surface is collected by the first detection module 22 for detection, so as to realize dark field detection. If it is two light sources, the two light sources respectively irradiate the wafer surface at a small incident angle (relative to the normal line) and a large incident angle (relative to the normal line), and the reflection light signal and the scattering light signal of the wafer surface are collected by the first detection module 22, so as to realize the combined detection of bright field and dark field.

[0031] The first film layer imaging system 3 comprises a second light source module 31 and a second detection module 32, the second light source module 31 is used for emitting illumination light to the wafer surface, and the second detection module 32 is used for collecting the film layer image of the wafer. It should be noted that the wafer is usually made of materials such as silicon and gallium arsenide, which has a high reflectivity and can form a strong reflection light signal under the irradiation of light at a small angle, so the wafer substrate can be detected by using the bright field detection method; and for defects (such as scratches and particles) on the wafer surface, scattering signals (such as scattering light of scratches in a fan shape perpendicular to the direction of the scratches, and scattering light of particles in a ring shape) can be formed under the irradiation of light at a large angle, which is more conducive to identifying whether there is a defect and the specific type, so the wafer substrate can also be detected by using the dark field detection method. The film layer on the wafer surface is usually made of transparent epoxy resin / photoresist and other materials, which has a low reflectivity and is difficult to form an effective reflection light signal under the irradiation of a light source, so the bright field detection is not suitable for defect detection of the film layer; if the dark field detection is used, due to the difference in physical properties between the wafer and the film layer, the scattering signal intensity difference between the two is huge, the substrate defect produces strong directional scattering (such as the reflection of scratches at a specific angle), and the scattering signal is strong, while the light scattering of the film layer bubble and other defects is almost isotropic, and the scattering signal is weak. When the strong scattering signal (substrate scattering) and the weak scattering signal (film layer scattering) coexist, the setting of the camera parameters can only meet the collection needs of one of them, thereby leading to the distortion of the signal data of the other, and further affecting the final detection result. In view of this, the wafer detection device provided in the embodiment of the application adopts two independent imaging systems, the first substrate imaging system 2 is used for realizing imaging of the wafer substrate, and the first film layer imaging system 3 is used for realizing imaging of the film layer.

[0032] The analysis module 4 is electrically connected with the first substrate imaging system 2 and the first film layer imaging system 3 respectively, and is used for analyzing the substrate image to obtain the substrate defect information of the wafer and analyzing the film layer image to obtain the film layer defect information of the wafer. Specifically, the analysis module 4 is used for receiving the substrate image sent by the first substrate imaging system 2 and the film layer image sent by the first film layer imaging system 3, and then analyzing the substrate image and the film layer image respectively to obtain the substrate defect information and the film layer defect information of the wafer.

[0033] Specifically, when the wafer detection device is used to detect the wafer, first, the wafer is placed on the stage 1 and fixed, then the first light source module 21 of the first substrate imaging system 2 and the second light source module 31 of the first film layer imaging system 3 are turned on, then the wafer is driven to do linear motion by the stage 1, and in the process of wafer motion, the substrate image of the wafer irradiated by the first light source module 21 is collected by the first detection module 22, and the film layer image of the wafer irradiated by the second light source module 31 is collected by the second detection module 32, and finally the substrate image and the film layer image are sent to the analysis module 4 for analysis to obtain the wafer detection result.

[0034] The wafer detection device of the embodiment can realize the synchronous detection of the wafer substrate and the film layer by using the first detection module 22 and the second detection module 32 to realize the wafer substrate imaging and the film layer imaging synchronously under the condition that the two groups of optical imaging systems do not interfere with each other, thereby greatly improving the efficiency of wafer detection.

[0035] Further, in the embodiment, the first light source module 21 is used to emit illumination light of a first preset wavelength which can easily penetrate the film layer to reach the substrate, and the second light source module 31 is used to emit illumination light of a second preset wavelength which can easily reflect or scatter on the surface of the film layer.

[0036] Specifically, when the first light source module 21 is selected, a light source with strong penetration and good reflection effect on the substrate is preferably selected, such as a light source with a wavelength in the range of 800-1100 nm for a wafer with a silicon substrate. When the second light source module 31 is selected, a wavelength with a large scattering cross section of the film layer material (such as a light source in the ultraviolet to visible light band) is preferably selected, so that defects such as bubbles and scratches can produce significant scattering signals, and ultraviolet light is strongly absorbed on the silicon surface and weakly reflected, which can better suppress the interference of the substrate reflected light.

[0037] Further, in order to improve the accuracy of wafer surface defect detection, on the basis of the above embodiment, in other embodiments, such as Figure 1As shown, the first light source module 21 includes a first bright field irradiation unit 211 and a first dark field irradiation unit 212. The first bright field irradiation unit 211 emits first illumination light to irradiate the wafer surface at a first incident angle, and the first dark field irradiation unit 212 emits second illumination light to irradiate the wafer surface at a second incident angle. The first detection module 22 is configured to acquire a bright field reflection image or a dark field scattering image of the wafer substrate. The second light source module 31 includes a second dark field irradiation unit 311 that emits third illumination light to irradiate the wafer surface at a third incident angle. The second detection module 32 is configured to acquire a film layer scattering image of the film layer on the wafer surface.

[0038] The first light source module 21 includes a first bright field irradiation unit 211 and a first dark field irradiation unit 212. The first bright field irradiation unit 211 is arranged at an angle relative to the wafer surface, such that the optical path of the first illumination light emitted by the first bright field irradiation unit 211 and the axis perpendicular to the wafer surface form a certain angle, and the angle is not 90°. That is, the first illumination light emitted by the first bright field irradiation unit 211 is obliquely irradiated on the wafer surface at a first incident angle, and the first incident angle is not equal to 0°. The first dark field irradiation unit 212 is arranged at another angle relative to the wafer surface, such that the second illumination light emitted by the first dark field irradiation unit 212 is obliquely irradiated on the wafer surface at a second incident angle, and the second incident angle is not equal to 0°. It should be noted that the first incident angle and the second incident angle are not equal. It should be understood that the first bright field irradiation unit 211 is configured to detect the bright field of the wafer substrate, and the first dark field irradiation unit 212 is configured to detect the dark field of the wafer substrate. In order to maximize the contrast of wafer defects and suppress signal noise, the first illumination light is incident at an angle close to the normal (e.g., the angle between the first illumination light and the wafer surface is 70°), and the second illumination light is incident at an angle away from the normal (e.g., the angle between the second illumination light and the wafer surface is 25°). The first detection module 22 is arranged on the optical path of the reflected light of the first illumination light, so as to receive the reflected light signal of the wafer surface to the first illumination light, and avoid the interference of the reflected light signal of the second illumination light, thereby forming a bright field reflection image. The scattering light signal of the wafer surface irradiated by the second illumination light can also be acquired by the first detection module 22, thereby forming a dark field scattering image.

[0039] The second light source module 31 comprises a second dark field irradiation unit 311. The second dark field irradiation unit 311 is used for dark field imaging of the film layer on the wafer surface. The second dark field irradiation unit 311 is arranged at another angle relative to the wafer surface, so that the third illumination light emitted by the second dark field irradiation unit 311 is obliquely irradiated on the wafer surface at a third incident angle, which is not equal to 0°. It should be noted that the third incident angle and the second incident angle can be equal or not equal, which needs to be set according to the material, thickness and other parameters of the film layer on the wafer surface. It should be understood that the film layer on the wafer surface has high transmittance and poor reflection effect on light signals, so the bright field detection method has poor defect detection effect on the film layer. Therefore, the embodiment adopts a dark field detection method for the film layer defect, uses the third illumination light emitted by the second irradiation unit to form a scattering light signal on the wafer surface at an angle away from the normal line (for example, the included angle between the third illumination light and the wafer surface is 20°), and forms a film layer scattering image of the wafer surface based on the scattering light signal. It should be noted that the analysis module 4 needs to correct the image distortion caused by the large incident angle before analyzing the film layer scattering image, and then detects the film layer defect.

[0040] Specifically, when scanning the wafer, first, the wafer to be detected is loaded onto the stage 1; second, the first bright field irradiation unit 211 is turned on and emits first illumination light to the wafer surface, and the second dark field irradiation unit 311 is turned on and emits third illumination light to the wafer surface; then, the stage 1 drives the wafer to move from the bright field imaging position to the dark field imaging position, the first detection module 22 acquires the bright field reflection image of the wafer substrate, and the second detection module 32 acquires the film layer scattering image of the wafer film layer; then, the first bright field irradiation unit 211 and the second dark field irradiation unit 311 are turned off, the first dark field irradiation unit 212 is turned on and emits second illumination light to the wafer surface, and the first detection module 22 acquires the dark field scattering image of the wafer substrate; finally, the analysis module 4 analyzes the bright field reflection image and the dark field scattering image to obtain the substrate defect information of the wafer, and analyzes the film layer scattering image to obtain the film layer defect information of the wafer.

[0041] The embodiment realizes multi-channel optical signal separation, multi-camera cooperative imaging by optimizing the optical system, solves the imaging interference of the wafer high-reflective substrate on the low-reflective film layer, synchronously detects the wafer surface defect and the film layer defect, improves the wafer defect detection efficiency, and reduces the equipment cost.

[0042] Further, the first bright field illumination unit 211, the first dark field illumination unit 212 and the second dark field illumination unit 311 in the embodiment can adopt light sources of various colors, such as white light sources, yellow light sources, red light sources, etc., which are not limited in the embodiment. It should be noted that the oblique illumination mode is easy to cause the deformation of the light spot shape, thereby affecting the image uniformity. Therefore, in the embodiment, the first bright field illumination unit 211, the first dark field illumination unit 212 and the second dark field illumination unit 311 all adopt narrow-band line light sources, and the length direction of the narrow-band line light source is orthogonal to the linear movement direction of the wafer, the narrow-band line light source emits a linear light beam, which can reduce the illumination width of the light source, avoid the deformation of the light spot, improve the imaging brightness and the image uniformity, and thus improve the image quality.

[0043] Further, as shown in the above embodiments, Figure 1 the first bright field illumination unit 211 and the first dark field illumination unit 212 each have a corresponding adjusting device for adjusting at least one of the pitch angle, the horizontal position and the vertical position so that the first incident angle is within the first preset angle range and the second incident angle is within the second preset angle range.

[0044] Specifically, the first bright field illumination unit 211 is arranged on the first adjusting device 213, and the first adjusting device 213 is used to adjust at least one of the pitch angle, the horizontal position and the vertical position so that the first incident angle of the first illumination light is within the first preset angle range. The first dark field illumination unit 212 is arranged on the second adjusting device 214, and the second adjusting device 214 is used to adjust at least one of the pitch angle, the horizontal position and the vertical position so that the second incident angle of the second illumination light is within the second preset angle range.

[0045] It should be noted that the first preset angle range is smaller than the second preset angle range.

[0046] Further, the first detection module 22 includes a first imaging lens 221, a first line array camera 222 and a first camera adjusting device 223. The first imaging lens 221 is used to receive the reflected light of the first illumination light on the base surface of the wafer or the scattered light of the second illumination light on the base surface of the wafer, and transmit the received light beam to the first line array camera 222. The first camera adjusting device 223 is used to adjust at least one of the pitch angle, the horizontal position and the vertical position of the first imaging lens 221, so that the optical axis of the first imaging lens 221 is symmetrical to the optical axis of the first bright field illumination unit 211 about the normal of the surface of the wafer, so as to better acquire the reflected light signal of the first illumination light and the scattered light signal of the second illumination light.

[0047] Further, as shown in the above embodiments, Figure 1As shown, the second dark-field illumination unit 311 has a corresponding adjusting device for adjusting at least one of the pitch angle, the horizontal position, and the vertical position so that the third incident angle is within a third preset angle range.

[0048] Specifically, the second dark-field illumination unit 311 is disposed on a third adjusting device 312, and the third adjusting device 312 adjusts at least one of the pitch angle, the horizontal position, and the vertical position so that the third incident angle of the third illumination light is within a third preset angle range.

[0049] Further, the second detection module 32 includes a second imaging lens 321, a second linear array camera 322, and a second camera adjusting device 323. The second imaging lens 321 is configured to receive the scattered light of the third illumination light on the film layer of the wafer and transmit the received light beam to the second linear array camera 322. The second camera adjusting device 323 is configured to adjust the pitch angle of the second imaging lens 321 so as to better acquire the scattered light signal of the third illumination light.

[0050] It should be noted that the third preset angle range is greater than the second preset angle range.

[0051] Further, in the embodiment, the first preset angle range is set to [55°, 85°], and the first incident angle is preferably set to 70°. The second preset angle range is set to [10°, 40°], and the second incident angle is preferably set to 25°. The third preset angle range is set to [0°, 40°], and the third incident angle is preferably set to 20°.

[0052] Further, as shown, Figure 1 The stage 1 includes a carrying part 11 and a driving part 12. The carrying part 11 is disposed on the driving part 12 and is configured to carry and define the wafer. The driving part 12 is configured to drive the carrying part 11 to move linearly so as to drive the wafer to move linearly.

[0053] Specifically, the driving part 12 includes one or more servo driving motors, and the carrying part 11 includes one or more wafer carrying blocks or vacuum chucks. The vacuum chucks are disposed on the output ends of the servo driving motors and are configured to adsorb and fix the wafer. The servo driving motors are configured to drive the wafer carrying blocks or the vacuum chucks to move linearly.

[0054] Further, it should be noted that in some embodiments, the second detection module 32 can also adjust the imaging angle of the second imaging lens 321 through the second camera adjusting device 323, so as to effectively detect different kinds of film layers.

[0055] Further, in some embodiments, the front side and the back side of the wafer can be covered with film layers, and the front side and the back side of the wafer need to be detected. In order to improve the detection efficiency, on the basis of the above-mentioned embodiments, in other embodiments, as shown in Figure 3 the wafer detection device further comprises a second substrate imaging system 5 and a second film layer imaging system 6. The first substrate imaging system 2 and the first film layer imaging system 3 are arranged on one side of the wafer, and the second substrate imaging system 5 and the second film layer imaging system 6 are arranged on the other side of the wafer. The first light source module 21 and the second light source module 31 are both used to emit illumination light to a first to-be-detected position on the front side of the wafer. The first detection module 22 is used to collect a substrate image at the first to-be-detected position. The second detection module 32 is used to collect a film layer image at the first to-be-detected position. The second substrate imaging system 5 comprises a third light source module 51 and a third detection module 52. The third light source module 51 is used to emit illumination light to a second to-be-detected position on the back side of the wafer. The third detection module 52 is used to collect a substrate image at the second to-be-detected position. The projection positions of the first to-be-detected position and the second to-be-detected position on the front side or the back side of the wafer are mutually staggered. The second film layer imaging system 6 comprises a fourth light source module 61 and a fourth detection module 62. The fourth light source module 61 is used to emit illumination light to the second to-be-detected position. The fourth detection module 62 is used to collect a film layer image at the second to-be-detected position. The analysis module 4 is further electrically connected with the second substrate imaging system 5 and the second film layer imaging system 6 (see Figure 4 ). The analysis module 4 is further used to analyze the substrate images and the film layer images of the first to-be-detected position and the second to-be-detected position to obtain defect information of the wafer substrate and the film layer.

[0056] It should be noted that in the present embodiment, the working principle of the second substrate imaging system 5 is the same as that of the first substrate imaging system 2, and the working principle of the second film layer imaging system 6 is the same as that of the first film layer imaging system 3. For details, please refer to the above-mentioned embodiments, which will not be described here.

[0057] Specifically, in the present embodiment, by arranging the first substrate imaging system 2 and the first film layer imaging system 3 on the front side of the wafer and arranging the second substrate imaging system 5 and the second film layer imaging system 6 on the back side of the wafer, the front side and the back side of the wafer can be detected at the same time, thereby improving the detection efficiency. Moreover, when detecting, the first to-be-detected position detected by the first substrate imaging system 2 and the first film layer imaging system 3 and the second to-be-detected position of the second substrate imaging system 5 and the second film layer imaging system 6 are mutually staggered, thereby effectively avoiding the problem of mutual interference of imaging light spots when detecting the front side and the back side of the wafer, thereby improving the detection efficiency while ensuring the detection accuracy.

[0058] Figure 5is a flowchart of a wafer detection method according to an embodiment of the present application. The wafer detection method is applied to the wafer detection device according to one of the above embodiments, and the wafer detection device comprises a stage, a first substrate imaging system, a first film layer imaging system, and an analysis module. As shown in Figure 5 the wafer detection method comprises the following steps:

[0059] Step S1: loading a wafer to be detected onto the stage;

[0060] Step S2: turning on the first light source module and the second light source module, the first light source module and the second light source module emit illumination light to the surface of the wafer, the stage drives the wafer to perform linear motion, the first detection module acquires a substrate image of the wafer, and the second detection module acquires a film layer image of the wafer;

[0061] Step S3: the analysis module analyzes the substrate image to obtain substrate defect information of the wafer, and analyzes the film layer image to obtain film layer defect information of the wafer.

[0062] It should be noted that the detailed contents of steps S1-S3 in the present embodiment can be referred to the above-mentioned wafer detection device embodiments, which will not be described here again.

[0063] The wafer detection method according to the present application synchronously realizes wafer substrate imaging and film layer imaging by using the first substrate imaging system and the first film layer imaging system respectively, thereby realizing synchronous detection of the wafer substrate and the film layer, and greatly improving the efficiency of wafer detection.

[0064] Further, the first light source module comprises a first bright field irradiation unit and a first dark field irradiation unit, the second light source module comprises a second dark field irradiation unit, and step S2 specifically comprises:

[0065] 1. The first bright field irradiation unit is turned on and emits first illumination light to the surface of the wafer, and the second dark field irradiation unit is turned on and emits third illumination light to the surface of the wafer.

[0066] 2. The stage drives the wafer to perform linear motion, the first detection module acquires a bright field reflection image of the wafer substrate, and the second detection module acquires a film layer scattering image of the wafer film layer.

[0067] 3. The first bright field irradiation unit and the second dark field irradiation unit are turned off, the first dark field irradiation unit is turned on and emits second illumination light to the surface of the wafer.

[0068] 4. The stage drives the wafer to move from the dark field imaging position to the bright field imaging position, and the first detection module acquires a dark field scattering image of the wafer substrate.

[0069] Further, the first bright field irradiation unit, the first dark field irradiation unit, and the second dark field irradiation unit each have a corresponding adjusting device.

[0070] Therefore, after the step of the first bright field irradiation unit being turned on and emitting the first illumination light to the wafer surface, and the second dark field irradiation unit being turned on and emitting the third illumination light to the wafer surface, the method further comprises:

[0071] 1.1, the adjusting device adjusts at least one of the pitch angle, the horizontal position, and the vertical position of the first bright field irradiation unit, so that the first incident angle of the first illumination light is in a first preset angle range.

[0072] 1.2, the adjusting device adjusts at least one of the pitch angle, the horizontal position, and the vertical position of the second dark field irradiation unit, so that the third incident angle of the third illumination light is in a third preset angle range.

[0073] After the step of the first dark field irradiation unit being turned on and emitting the second illumination light to the wafer surface, the method further comprises:

[0074] 3.1, the adjusting device adjusts at least one of the pitch angle, the horizontal position, and the vertical position of the first dark field irradiation unit, so that the second incident angle of the second illumination light is in a second preset angle range.

[0075] It should be noted that in the embodiment, the first preset angle range is smaller than the second preset angle range, and the third preset angle range is larger than the second preset angle range.

[0076] Further, in the step S2, the operation of the first light source module and the second light source module emitting the illumination light to the wafer surface specifically comprises:

[0077] The first light source module emits the illumination light of the first preset wavelength which is easy to penetrate the film layer to reach the substrate to the wafer surface, and the second light source module emits the illumination light of the second preset wavelength which is easy to reflect or scatter on the surface of the film layer to the wafer surface.

[0078] It should be understood that the detailed contents of the steps in each embodiment of the wafer detection method are referred to the contents of each embodiment of the wafer detection device, which will not be repeated here.

[0079] The above is only the embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the contents of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A wafer inspection apparatus characterized by comprising: It includes: A carrier for carrying a wafer, the wafer having a substrate and a film layer covering the substrate; A first substrate imaging system including a first light source module and a first detection module, the first light source module being configured to emit illumination light to the surface of the wafer, and the first detection module being configured to acquire a substrate image of the wafer; A first film layer imaging system including a second light source module and a second detection module, the second light source module being configured to emit illumination light to the surface of the wafer, and the second detection module being configured to acquire a film layer image of the wafer; An analysis module electrically connected to the first substrate imaging system and the first film layer imaging system, respectively, for analyzing the substrate image to obtain substrate defect information of the wafer, and analyzing the film layer image to obtain film layer defect information of the wafer; The first light source module includes a first bright field irradiation unit and a first dark field irradiation unit, the first bright field irradiation unit emits first illumination light to the surface of the wafer at a first incident angle, the first dark field irradiation unit emits second illumination light to the surface of the wafer at a second incident angle, and the first detection module is configured to acquire a bright field reflection image or a dark field scattering image of the substrate of the wafer; The second light source module includes a second dark field irradiation unit, the second dark field irradiation unit emits third illumination light to the surface of the wafer at a third incident angle, and the second detection module is configured to acquire a film layer scattering image of the film layer on the surface of the wafer; The third incident angle is smaller than the first incident angle, and the second incident angle is smaller than the first incident angle.

2. The wafer inspection apparatus according to claim 1, wherein The first bright field irradiation unit and the first dark field irradiation unit each have a corresponding adjusting device for adjusting at least one of the pitch angle, the horizontal position, and the vertical position so that the first incident angle is within a first preset angle range and the second incident angle is within a second preset angle range, the first preset angle range is set to [55°, 85°], and the second preset angle range is set to [10°, 40°].

3. The wafer inspection apparatus according to claim 2, wherein The first detection module includes a first imaging lens, a first linear array camera, and a first camera adjusting device, the first imaging lens is configured to receive reflected light of the first illumination light on the substrate surface of the wafer or scattered light of the second illumination light on the substrate surface of the wafer, and transmit the received light beam to the first linear array camera, and the first camera adjusting device is configured to adjust at least one of the pitch angle, the horizontal position, and the vertical position of the first imaging lens so that the optical axis of the first imaging lens and the optical axis of the first bright field irradiation unit are symmetric about the normal of the surface of the wafer.

4. The wafer inspection apparatus according to claim 2, wherein The second dark field irradiation unit has a corresponding adjusting device for adjusting at least one of the pitch angle, the horizontal position, and the vertical position so that the third incident angle is within a third preset angle range, and the third preset angle range is set to [0°, 40°].

5. The wafer inspection apparatus according to claim 4, wherein The second detecting module comprises a second imaging lens, a second linear array camera and a second camera adjusting device, the second imaging lens is used for receiving the scattered light of the third illumination light on the film layer of the wafer and transmitting the received light beam to the second linear array camera, and the second camera adjusting device is used for adjusting the pitch angle of the second imaging lens.

6. The wafer inspection apparatus of claim 1, wherein The first light source module is used for emitting illumination light of a first preset wavelength which can easily penetrate the film layer to reach the substrate, and the second light source module is used for emitting illumination light of a second preset wavelength which is easy to be reflected or scattered on the surface of the film layer.

7. The wafer inspection apparatus of claim 1, wherein The carrier comprises a carrying part and a driving part, the carrying part is arranged on the driving part, the carrying part is used for carrying and limiting the wafer, and the driving part is used for driving the carrying part to move to drive the wafer to linearly move.

8. The wafer inspection apparatus of claim 1, wherein It also comprises a second substrate imaging system and a second film layer imaging system; The first substrate imaging system and the first film layer imaging system are arranged on one side of the wafer, and the second substrate imaging system and the second film layer imaging system are arranged on the other side of the wafer; The first light source module and the second light source module are both used for emitting illumination light to a first to-be-detected position on the front surface of the wafer, the first detecting module is used for collecting the substrate image at the first to-be-detected position, and the second detecting module is used for collecting the film layer image at the first to-be-detected position; The second substrate imaging system comprises a third light source module and a third detecting module, the third light source module is used for emitting illumination light to a second to-be-detected position on the back surface of the wafer, and the third detecting module is used for collecting the substrate image at the second to-be-detected position, the projection positions of the first to-be-detected position and the second to-be-detected position on the front surface or the back surface of the wafer are staggered with each other; The second film layer imaging system comprises a fourth light source module and a fourth detecting module, the fourth light source module is used for emitting illumination light to the second to-be-detected position, and the fourth detecting module is used for collecting the film layer image at the second to-be-detected position; The analysis module is also electrically connected with the second substrate imaging system and the second film layer imaging system respectively, and the analysis module is also used for analyzing the substrate images and the film layer images of the first to-be-detected position and the second to-be-detected position to obtain the defect information of the wafer substrate and the film layer.

9. A wafer inspection method characterized by comprising: It is applied to the wafer detection device in any one of claims 1-8; the method comprises: loading the wafer to be detected to the carrier; controlling the first light source module and the second light source module to be turned on, the first light source module and the second light source module emit illumination light to the surface of the wafer, the carrier drives the wafer to linearly move, the first detecting module obtains the substrate image of the wafer, and the second detecting module obtains the film layer image of the wafer; the analysis module analyzes the substrate image to obtain the substrate defect information of the wafer and analyzes the film layer image to obtain the film layer defect information of the wafer.

10. The wafer inspection method of claim 9, wherein, The first light source module comprises a first bright field irradiation unit and a first dark field irradiation unit, and the second light source module comprises a second dark field irradiation unit. controlling the first light source module and the second light source module to be turned on, the first light source module and the second light source module emitting illumination light to the wafer surface, the stage driving the wafer to perform linear motion, the first detection module acquiring a substrate image of the wafer, and the second detection module acquiring a film layer image of the wafer, comprising: the first bright field irradiation unit is turned on and emits first illumination light to the wafer surface, and the second dark field irradiation unit is turned on and emits third illumination light to the wafer surface; the stage drives the wafer to perform linear motion, the first detection module acquires a bright field reflection image of the wafer substrate, and the second detection module acquires a film layer scattering image of the wafer film layer; the first bright field irradiation unit and the second dark field irradiation unit are turned off, and the first dark field irradiation unit is turned on and emits second illumination light to the wafer surface; the stage drives the wafer to move from the dark field imaging position to the bright field imaging position, and the first detection module acquires a dark field scattering image of the wafer substrate.

11. The wafer inspection method of claim 10, wherein, The first bright field irradiation unit, the first dark field irradiation unit, and the second dark field irradiation unit each have a corresponding adjusting device; after the first bright field irradiation unit is turned on and emits first illumination light to the wafer surface, and the second dark field irradiation unit is turned on and emits third illumination light to the wafer surface, the adjusting device adjusts at least one of the pitch angle, the horizontal position, and the vertical position of the first bright field irradiation unit, so that the first incident angle of the first illumination light is within a first preset angle range; and the adjusting device adjusts at least one of the pitch angle, the horizontal position, and the vertical position of the second dark field irradiation unit, so that the third incident angle of the third illumination light is within a third preset angle range; after the first dark field irradiation unit is turned on and emits second illumination light to the wafer surface, the adjusting device adjusts at least one of the pitch angle, the horizontal position, and the vertical position of the first dark field irradiation unit, so that the second incident angle of the second illumination light is within a second preset angle range; The first preset angle range is smaller than the second preset angle range, and the third preset angle range is larger than the second preset angle range.

12. The wafer inspection method of claim 9, wherein, The first light source module and the second light source module emit illumination light to the wafer surface, comprising: The first light source module emits first preset wavelength illumination light that can easily penetrate the film layer to reach the substrate to the wafer surface, and the second light source module emits second preset wavelength illumination light that is easily reflected or scattered on the surface of the film layer to the wafer surface.

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