Wafer particle detection device and method
By combining the pre-detection light source and the main detection light source, rapid positioning and detection of wafer particles are achieved, solving the problem of long detection time in existing technologies and improving the throughput of the detection equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI INTEGRATED CIRCUIT EQUIPMENT & MATERIALS INDUSTRY INNOVATION CENTER CO LTD
- Filing Date
- 2024-11-11
- Publication Date
- 2026-05-12
AI Technical Summary
In existing wafer particle inspection devices, the pre-scanning process of the pre-inspection light source is performed separately, resulting in a long inspection time and affecting the throughput of the inspection equipment.
The method combines a pre-detection light source and a main detection light source. The pre-detection light source first emits a first laser for reflection detection, and the main detection light source then emits a second laser for scattering detection. The two methods overlap in time but do not exceed the time of the first scan path. The particle area can be quickly located and detected by using a reflection light detection module and a photoelectronic detection module.
This significantly shortens the testing time, increases the throughput of the testing equipment, and improves testing efficiency.
Smart Images
Figure CN122016843A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor equipment, and in particular to a wafer particle detection device and method. Background Technology
[0002] Particles on wafers can introduce defects into manufactured semiconductor devices, thereby affecting their yield. Currently, particle detection on wafers can be performed using laser scattering detection tools. As laser power intensity increases, the size of detectable particles decreases, leading to improved detection sensitivity.
[0003] Existing particle inspection devices include a pre-inspection light source and a main inspection light source. The pre-inspection light source is a diffused light source. It first scans the entire wafer using the pre-inspection light source, with scanning routes of dozens or even hundreds of loops. Based on the results of the pre-inspection light source scan, the location of large particles on the wafer is located. Then, a high-power main inspection light source scans the wafer, reducing the laser power in areas with large particles. The pre-inspection light source pre-scan is performed separately in advance, resulting in a relatively long inspection time and affecting the throughput of the inspection equipment.
[0004] Therefore, how to solve the above-mentioned technical problems should be a key focus for those skilled in the art. Summary of the Invention
[0005] The purpose of this application is to provide a wafer particle inspection device and method to shorten the inspection time.
[0006] To address the aforementioned technical problems, this application provides a wafer particle inspection device, comprising:
[0007] A pre-detection light source is used to emit a first laser beam toward the wafer, and the first laser beam is reflected on the surface of the wafer.
[0008] A reflected light detection module is used to receive the reflected first laser light and determine the target particle region on the wafer based on the reflected first laser light.
[0009] The main detection light source is used to emit a second laser beam toward the wafer, and the second laser beam is scattered on the surface of the wafer.
[0010] The optoelectronic detection module is used to receive the scattered second laser and to detect particles based on the scattered second laser.
[0011] The pre-detection light source emits the first laser onto the wafer earlier than the main detection light source emits the second laser onto the wafer, and the earlier time does not exceed the time required to scan the first scan path.
[0012] Optionally, the wavelength of the first laser is greater than the wavelength of the second laser.
[0013] Optionally, the wavelength range of the first laser is 300nm~390nm, and the wavelength range of the second laser is 200nm~350nm.
[0014] Optionally, it also includes:
[0015] The first filter is located at the laser emission port of the main detection light source.
[0016] Optionally, it also includes:
[0017] The second filter is located at the laser input of the optoelectronic detection module.
[0018] Optionally, it also includes:
[0019] A shield is located at the laser entry point of the reflected light detection module.
[0020] Optionally, it also includes:
[0021] A rotating component for rotating the wafer.
[0022] Optionally, the reflected light detection module includes: a difference frequency module, an optical amplification element, and an optoelectronic imaging component arranged sequentially along the laser propagation path. The difference frequency module is used to convert the first laser after reflection into a target laser of the target wavelength. The optical amplification element is used to amplify the target laser. The optoelectronic imaging component is used to perform optoelectronic conversion on the received amplified target laser and determine the target particle region.
[0023] This application also provides a wafer particle inspection method based on the wafer particle inspection device described above, comprising:
[0024] A pre-detection light source is controlled to emit a first laser beam toward the wafer, and the first laser beam is reflected on the wafer.
[0025] Before the first laser finishes scanning along the first scan path, the main detection light source is controlled to emit a second laser toward the wafer, and the second laser is scattered on the wafer.
[0026] The reflected light detection module receives the reflected first laser and determines the target particle region on the wafer based on the reflected first laser.
[0027] The optoelectronic detection module receives the scattered second laser and performs particle detection based on the scattered second laser until all scanning routes are completed.
[0028] Optionally, it also includes:
[0029] The wafer is rotated by a rotating component.
[0030] This application provides a wafer particle inspection device, comprising: a pre-inspection light source for emitting a first laser beam onto the wafer, the first laser beam being reflected on the wafer surface; a reflected light detection module for receiving the reflected first laser beam and determining a target particle region on the wafer based on the reflected first laser beam; a main inspection light source for emitting a second laser beam onto the wafer, the second laser beam being scattered on the wafer surface; and a photoelectric detection module for receiving the scattered second laser beam and performing particle detection based on the scattered second laser beam; wherein the time at which the pre-inspection light source emits the first laser beam onto the wafer is earlier than the time at which the main inspection light source emits the second laser beam onto the wafer, the earlier time not exceeding the time required to scan the first scan path.
[0031] As can be seen, the wafer particle inspection device in this application includes a pre-inspection light source, a main inspection light source, a reflected light detection module, and a photoelectric detection module. The pre-inspection light source emits a first laser, and the main inspection light source emits a second laser. The first laser is reflected, and the second laser is scattered. The reflected light detection module determines the target particle region through the reflected first laser, and the photoelectric detection module performs detection through the scattered first laser. During the inspection process, the pre-inspection light source emits the first laser before the main inspection light source emits the second laser, and this pre-inspection light source does not exceed the time required to scan the pre-inspection light source along the first scan path. Then, the main inspection light source and the pre-inspection light source emit light simultaneously and scan along the scan path. Therefore, the pre-inspection light source has a very short pre-scanning time, and the pre-inspection light source and the main inspection light source can be considered to be scanning almost simultaneously. Therefore, the particle inspection device in this application can significantly shorten the inspection time and increase the throughput of the inspection machine.
[0032] In addition, this application also provides a particle detection method with the above advantages. Attached Figure Description
[0033] To more clearly illustrate the technical solutions of the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0034] Figure 1 This is a schematic diagram of particle detection on a wafer in the prior art;
[0035] Figure 2 This is a schematic diagram of a wafer particle inspection device provided in an embodiment of this application;
[0036] Figure 3This is a schematic diagram illustrating particle detection on a wafer according to an embodiment of this application;
[0037] Figure 4 This is a schematic diagram of the structure of the reflected light detection module provided in the embodiments of this application;
[0038] In the figure, 1. Wafer, 2. Pre-inspection light source, 3. Main inspection light source, 4. Pre-inspection light source, 5. Main inspection light source, 6. Reflected light detection module, 7. Optoelectronic detection module, 8. Second filter, 9. Mask, 61. Differential frequency module, 62. Optical amplification element, 63. Optoelectronic imaging component. Detailed Implementation
[0039] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0041] As described in the background section, currently, when conducting detection, such as Figure 1 As shown, Figure 1 The dashed line represents the scanning route. First, the pre-inspection light source 2 is used to pre-scan the entire wafer 1, and then the high-power main inspection light source 3 is used to scan the wafer 1. The light emitted by the main inspection light source 3 is scattered light. The pre-scan of the pre-inspection light source 2 is performed separately in advance, which results in a relatively long inspection time and affects the throughput of the inspection machine.
[0042] In view of this, this application provides a wafer particle inspection device, please refer to... Figures 2 to 3 ,include:
[0043] Pre-detection light source 4 is used to emit a first laser beam toward wafer 1, and the first laser beam is reflected on the surface of wafer 1;
[0044] The reflected light detection module 6 is used to receive the reflected first laser and determine the target particle region on the wafer 1 based on the reflected first laser.
[0045] The main detection light source 5 is used to emit a second laser towards the wafer 1, and the second laser is scattered on the surface of the wafer 1;
[0046] The optoelectronic detection module 7 is used to receive the scattered second laser and to detect particles based on the scattered second laser.
[0047] The time when the pre-detection light source 4 emits the first laser to the wafer 1 is earlier than the time when the main detection light source 5 emits the second laser to the wafer 1, and the earlier time is no more than the time of scanning the first scan route.
[0048] Wafer 1 has multiple scan lines, such as Figure 3 As shown by the dashed line. The pre-detection light source 4 and the main detection light source 5 will scan all the scanning lines.
[0049] When scanning wafer 1, the pre-detection light source 4 and the main detection light source 5 can control the rotation of wafer 1, while the positions of the pre-detection light source 4 and the main detection light source 5 are fixed.
[0050] As one possible implementation, the wafer 1 particle detection device may also include a rotating component for rotating the wafer 1.
[0051] The pre-detection light source 4 and the main detection light source 5 can be fixed in one position. According to the law of light reflection, the reflected light detection module 6 is set in a position opposite to the pre-detection light source 4, so that the first laser enters the reflected light detection module 6 at the reflection angle after being reflected on the wafer 1.
[0052] The pre-detection light source 4 uses the reflected light detection mode, which can ignore the scattering effect of the main detection light source 5 and do not interfere with each other.
[0053] It should be noted that the specific structure of the reflected light detection module 6 is not limited in this embodiment and can be set by the user.
[0054] As one possible implementation method, such as Figure 4 As shown, the reflected light detection module 6 includes: a difference frequency module 61, an optical amplification element 62, and an optoelectronic imaging component 63, which are sequentially distributed along the laser propagation path. The difference frequency module 61 is used to convert the first laser after reflection into a target laser of the target wavelength. The optical amplification element 62 is used to amplify the target laser. The optoelectronic imaging component 63 is used to perform optoelectronic conversion on the received amplified target laser and determine the target particle region.
[0055] Assuming the wavelength of the first laser is λ1, the wavelength of the target laser obtained after the first laser is reflected and passes through the difference frequency module 61 is λ0 ≥ 2λ1. The material of the difference frequency module 61 can be a nonlinear crystal, etc., and is not limited in this embodiment.
[0056] The function of the optical amplification element 62 is to amplify the target laser. The optical amplification element 62 can be a concave lens.
[0057] The photoelectric imaging component 63 receives the target laser, converts the photoelectrons of the target laser into electrical signals, and marks electrical signals with peak values lower than a preset peak threshold as defect signals.
[0058] The second laser emitted by the main detection light source 5 is a scattering light source, which is scattered on the surface of wafer 1. The optoelectronic detection module 7 receives the scattered second laser and performs particle detection. The detection process of the optoelectronic detection module 7 is the same as that in the prior art, and will not be described in detail here.
[0059] It should be noted that the wavelength relationship between the first laser and the second laser is not limited in this embodiment.
[0060] As one possible implementation, the wavelength λ1 of the first laser is greater than the wavelength λ2 of the second laser. That is, by using different light sources for the pre-detection light source 4 and the main detection light source 5, interference between the pre-detection light source 4 and the main detection light source 5 can be eliminated.
[0061] During the pre-scan, the pre-detection light source 4 has lower requirements for the particle size to be detected. Therefore, compared to the second laser, the first laser has a relatively longer wavelength and relatively lower energy, which is sufficient to meet the requirements.
[0062] In one embodiment of this application, the wavelength range of the first laser is 300nm~390nm, and the wavelength range of the second laser is 200nm~350nm.
[0063] For example, the wavelength of the first laser can be 300nm, 320nm, 340nm, 350nm, 370nm, 390nm, etc. For example, the wavelength of the second laser can be 200nm, 220nm, 240nm, 260nm, 300nm, 320nm, 340nm, 350nm, etc.
[0064] The target particle region is the region where the particle size is larger than a preset particle size threshold. The preset particle size threshold is not limited in this embodiment and depends on the situation.
[0065] When the second laser of the main detection light source 5 scans through the target particle area, the power of the second laser is reduced or turned off. The reason is that laser heating can cause particle explosion (i.e., particle ablation). Particle ablation may break down a large particle into hundreds of smaller particles in the surrounding area of wafer 1, leading to particle contamination. Furthermore, increasing the laser power density lowers the size threshold for particle ablation.
[0066] The reason why the pre-detection light source 4 emits the first laser to the wafer 1 earlier than the main detection light source 5 is to allow time for the reaction of the reflected light detection module 6.
[0067] It should be noted that in this embodiment, there is no limitation on the time when the pre-detection light source 4 emits the first laser beam onto the wafer 1 before the main detection light source 5; it can be determined based on the reaction time of the reflected light detection module 6. The shorter the reaction time of the reflected light detection module 6, the shorter the time when the pre-detection light source 4 emits the first laser beam onto the wafer 1 before the main detection light source 5, and the shorter the detection time.
[0068] The time when the pre-detection light source 4 emits the first laser to the wafer 1 is no more than the time when the first scan path is scanned. That is, before the first laser finishes scanning the first scan path, the main detection light source 5 turns on and emits the second laser to the wafer 1.
[0069] In this embodiment, the wafer 1 particle detection device includes a pre-detection light source 4, a main detection light source 5, a reflected light detection module 6, and a photoelectronic detection module 7. The pre-detection light source 4 emits a first laser, and the main detection light source 5 emits a second laser. The first laser is reflected, and the second laser is scattered. The reflected light detection module 6 determines the target particle region through the reflected first laser, and the photoelectronic detection module 7 performs detection through the scattered first laser. During the detection process, the time when the pre-detection light source 4 emits the first laser is no earlier than the time when the main detection light source 5 emits the second laser, and this time does not exceed the time it takes for the pre-detection light source 4 to scan along the first scan path. Then, the main detection light source 5 and the pre-detection light source 4 emit light simultaneously and scan along the scan path. Therefore, the pre-detection light source 4 scans very quickly, and the pre-detection light source 4 and the main detection light source 5 can be considered to be scanning almost simultaneously. Therefore, the particle detection device in this embodiment can greatly shorten the detection time and increase the throughput of the detection machine.
[0070] Based on the above embodiments, in one embodiment of this application, the wafer 1 particle detection device may further include:
[0071] The first filter is located at the laser emission port of the main detection light source 5.
[0072] By setting the first filter, the laser emitted by the main detection light source 5 can be filtered, allowing the first laser with wavelength λ1 to selectively pass through while filtering out lasers of other wavelengths, thus avoiding the influence of the scattered light from the pre-detection light source 4 on the main detection light source 5.
[0073] Please refer to Figure 2 Based on any of the above embodiments, in one embodiment of this application, the wafer 1 particle detection device may further include:
[0074] The second filter 8 is located at the laser entrance of the optoelectronic detection module 7.
[0075] By setting the second filter 8, light other than the scattered first laser can be filtered out, thus preventing the scattered light from the pre-detection light source 4 from having an adverse effect on the optoelectronic detection module 7.
[0076] Please refer to Figure 2 Based on any of the above embodiments, in one embodiment of this application, the wafer 1 particle detection device may further include:
[0077] The shield 9 is located at the laser entrance of the reflected light detection module 6.
[0078] The function of the shield 9 is to absorb the laser light from the main detection light source 5, prevent the light from the main detection light source 5 from entering the reflected light detection module 6, and improve the detection accuracy of the reflected light detection module 6.
[0079] This application also provides a wafer particle inspection method based on the wafer particle inspection apparatus of the above embodiments, the method including:
[0080] Step S101: Control the pre-detection light source to emit a first laser towards the wafer, and the first laser is reflected on the wafer;
[0081] Step S102: Before the first laser finishes scanning along the first scan path, control the main detection light source to emit a second laser towards the wafer, and the second laser is scattered on the wafer;
[0082] Step S103: The reflected light detection module receives the reflected first laser and determines the target particle region on the wafer based on the reflected first laser.
[0083] Step S104: The optoelectronic detection module receives the scattered second laser and performs particle detection based on the scattered second laser until all scanning routes are completed.
[0084] In this embodiment of the wafer particle detection method, a pre-detection light source emits a first laser, and a main detection light source emits a second laser. The first laser is reflected, and the second laser is scattered. The reflected light detection module determines the target particle region through the reflected first laser, and the optoelectronic detection module performs detection through the scattered first laser. During the detection process, the pre-detection light source emits the first laser before the main detection light source emits the second laser, and the time between the pre-detection light source emission and the main detection light source emission does not exceed the time required to scan the pre-detection light source along the first scan path. Then, the main detection light source and the pre-detection light source emit light simultaneously and scan along the scan path. Therefore, the pre-detection light source has a very short pre-scanning time, and the pre-detection light source and the main detection light source can be considered to be scanning almost simultaneously. Therefore, the particle detection method in this embodiment can significantly shorten the detection time and increase the throughput of the detection machine.
[0085] Based on the above embodiments, in one embodiment of this application, the wafer particle detection method further includes: rotating the wafer by means of a rotating component.
[0086] As the wafer rotates, the pre-detection light source and the main detection light source emit lasers.
[0087] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0088] The wafer particle detection device and method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the solution and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.
Claims
1. A wafer particle detection device, characterized in that, include: A pre-detection light source is used to emit a first laser beam toward the wafer, and the first laser beam is reflected on the surface of the wafer. A reflected light detection module is used to receive the reflected first laser light and determine the target particle region on the wafer based on the reflected first laser light. The main detection light source is used to emit a second laser beam toward the wafer, and the second laser beam is scattered on the surface of the wafer. The optoelectronic detection module is used to receive the scattered second laser and to detect particles based on the scattered second laser. The pre-detection light source emits the first laser onto the wafer earlier than the main detection light source emits the second laser onto the wafer, and the earlier time does not exceed the time required to scan the first scan path.
2. The wafer particle inspection device as described in claim 1, characterized in that, The wavelength of the first laser is greater than the wavelength of the second laser.
3. The wafer particle inspection device as described in claim 2, characterized in that, The wavelength range of the first laser is 300nm~390nm, and the wavelength range of the second laser is 200nm~350nm.
4. The wafer particle inspection device as described in claim 1, characterized in that, Also includes: The first filter is located at the laser emission port of the main detection light source.
5. The wafer particle inspection device as described in claim 1, characterized in that, Also includes: The second filter is located at the laser input of the optoelectronic detection module.
6. The wafer particle inspection device as described in claim 1, characterized in that, Also includes: A shield is located at the laser entry point of the reflected light detection module.
7. The wafer particle inspection device as described in claim 1, characterized in that, Also includes: A rotating component for rotating the wafer.
8. The wafer particle inspection apparatus according to any one of claims 1 to 7, characterized in that, The reflected light detection module includes: a difference frequency module, an optical amplification element, and an optoelectronic imaging component arranged sequentially along the laser propagation path. The difference frequency module is used to convert the first laser after reflection into a target laser of the target wavelength. The optical amplification element is used to amplify the target laser. The optoelectronic imaging component is used to perform optoelectronic conversion on the received amplified target laser and determine the target particle region.
9. A wafer particle detection method based on the wafer particle detection device according to claim 1, characterized in that, include: A pre-detection light source is controlled to emit a first laser beam toward the wafer, and the first laser beam is reflected on the wafer. Before the first laser finishes scanning along the first scan path, the main detection light source is controlled to emit a second laser toward the wafer, and the second laser is scattered on the wafer. The reflected light detection module receives the reflected first laser and determines the target particle region on the wafer based on the reflected first laser. The optoelectronic detection module receives the scattered second laser and performs particle detection based on the scattered second laser until all scanning routes are completed.
10. The wafer particle detection method as described in claim 9, characterized in that, Also includes: The wafer is rotated by a rotating component.