Detection device and detection method

Abstract

The detection equipment provided by the embodiment of the invention comprises a light source assembly, a light path system, a detection system and a light path adjustment module. The light path system is used for guiding the light source assembly to irradiate the wafer to generate a to-be-detected light signal. The detection system includes a first channel and a second channel. The first channel receives a to-be-detected optical signal to obtain a first optical signal of the wafer under a first resolution, and the second channel receives the to-be-detected optical signal to obtain a second optical signal of the wafer under a second resolution. The optical path adjusting module is used for adjusting the transmission direction of the to-be-detected optical signal, so that the first channel and the second channel receive the to-be-detected optical signal. Wherein the first resolution ratio is greater than the second resolution ratio. The same set of optical path system is multiplexed, so that the detection cost is reduced, the space is saved, the accuracy and consistency of different detection channels can be improved, the requirements of comprehensive monitoring of overall performance parameters and local accurate detection are better met, and a more comprehensive and accurate detection result is favorably provided.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor detection technology, and in particular, to a detection device and a detection method. Background Art

[0002] With the development of science and technology and the growth of market demand, the semiconductor industry has put forward higher requirements on the production capacity and efficiency of wafers. Since large-sized wafers can accommodate more transistors and circuit elements on the same chip, high chip integration can be achieved, which can meet the market demand for more functions and higher performance.

[0003] With the advantages brought by large-size wafers, quality control and defect detection in the production process have become more complex and critical. At present, the field of wafer defect detection mainly covers three major methods: appearance inspection, electron beam inspection and optical inspection. Among them, optical inspection technology, with its non-contact measurement, high-resolution imaging and wide applicability, has shown great potential in wafer surface quality assessment, optical property analysis and microstructure detection, and has become the focus of industry attention.

[0004] However, for large-sized wafers, the defect detection task is more difficult. It is necessary to achieve comprehensive monitoring of the overall performance parameters of the wafer, and to have the ability to accurately detect local tiny defects in real time. Existing detection equipment often finds it difficult to maintain high detection efficiency while taking into account local accurate detection. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a detection device and a detection method, which aims to take into account the requirements of comprehensive monitoring of the overall performance parameters of large-size wafers and local precise detection, so as to achieve efficient overall parameter detection and accurate local parameter detection.

[0006] On the one hand, a detection device provided by one embodiment of the present invention includes a light source assembly, an optical path system, a detection system and an optical path adjustment module. The optical path system is used to guide the light source assembly to irradiate the wafer to generate a light signal to be detected. The detection system includes a first channel and a second channel. The first channel receives the light signal to be detected to obtain a first light signal of the wafer at a first resolution, and the second channel receives the light signal to be detected to obtain a second light signal of the wafer at a second resolution. The optical path adjustment module is used to adjust the transmission direction of the light signal to be detected so that the first channel and the second channel receive the light signal to be detected. Wherein, the first resolution is greater than the second resolution.

[0007] The addition of the optical path adjustment module enables the detection of wafers with different resolutions in the same detection equipment, which is conducive to the spatial multiplexing of different resolutions, thereby improving the flexibility and diversity of wafer detection and facilitating the rapid switching of detection needs. By setting at least two detection channels with different resolutions, it is conducive to real-time and rapid acquisition of the performance parameters of the wafer at different resolutions. In addition, since the same optical path system is reused without the need to set up two independent optical path systems, it not only helps to reduce detection costs and save space, but also helps to improve the accuracy and consistency of detection results of different detection channels. Compared with detection equipment with a single detection channel, it is conducive to enhancing the adaptability and functionality of the detection equipment, improving the detection efficiency of the detection equipment, and will not increase the complexity of the detection equipment too much due to the addition of detection channels, nor will it sacrifice the accuracy of the detection. Through this multi-channel design, the needs of comprehensive monitoring of overall performance parameters and local precise detection can be better met, which is conducive to providing more comprehensive and accurate detection results, thereby improving the overall detection performance and reliability.

[0008] On the other hand, an embodiment of the present invention provides a detection method for detecting wafers. The detection method includes controlling the optical path system to generate an optical signal to be detected for the wafer according to a control instruction, and adjusting the position of the optical path adjustment module so that the first sensor in the first channel of the detection system receives the optical signal to be detected to obtain a first optical signal at a first resolution, and / or the second sensor in the second channel of the detection system receives the optical signal to be detected to obtain a second optical signal at a second resolution; processing the first optical signal and the second optical signal to obtain the performance parameters of the wafer; wherein the first resolution is greater than the second resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. The same or similar reference numerals are used in the drawings to represent the same or similar elements. The drawings are only schematic, and the sizes and proportions of the elements in the drawings are not necessarily accurate.

[0010] Figure 1 A schematic diagram of the structure of a detection device provided in one embodiment of the present invention.

[0011] Figure 2 A schematic diagram of the structure of a detection device provided in one embodiment of the present invention.

[0012] Figure 3 A schematic structural diagram of a first channel and a second channel provided in one embodiment of the present invention.

[0013] Figure 4 A schematic structural diagram of a first channel provided in one embodiment of the present invention.

[0014] Figure 5 A schematic diagram of the structure of a detection device provided in one embodiment of the present invention.

[0015] Figure 6 A schematic diagram of the structure of a detection device provided in one embodiment of the present invention.

[0016] Figure 7 A schematic diagram of the structure of a detection device provided in one embodiment of the present invention.

[0017] Figure 8 A schematic structural diagram of a movable scanning galvanometer provided in one embodiment of the present invention.

[0018] Fig. 9 A flow chart of a detection method provided by an embodiment of the present invention.

[0019] Figures 10a-10d Different scanning path diagrams for the entire wafer are provided in one embodiment of the present invention.

[0020] Fig.11 A schematic diagram of local scanning of a wafer provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described exemplarily below in conjunction with the accompanying drawings. It should be understood that the present invention can be implemented in a variety of ways and should not be construed as being limited to the embodiments described here, which are only for a more thorough and clear understanding of the present invention.

[0022] In the manufacturing process of third-generation semiconductors, the detection of performance parameters such as stress and warpage of wafers is crucial for the entire wafer and local areas, and has a great impact on quality control in the subsequent manufacturing process. Therefore, in the inspection of large-size wafers, comprehensive monitoring of overall performance parameters and accurate detection of local defects complement each other and are inseparable.

[0023] Below, the structure of the wafer detection device in at least one embodiment of the present invention is described in detail in conjunction with the accompanying drawings. It can be understood that in the embodiments of the present invention, the azimuth descriptions such as "upper" and "lower" are relative rather than absolute. When the wafer detection device or detection method provided by the embodiments of the present invention is placed according to the positions shown in the accompanying drawings, these azimuth descriptions may be applicable.

[0024] refer to Figure 1 An embodiment of the present disclosure provides a detection device 100 suitable for detecting a wafer 110 , which may include a light source assembly 120 and an optical path system 130 .

[0025] The optical path system 130 is used to guide the light source assembly 120 to irradiate the wafer 110 to generate the optical signal 10 to be detected. The light source assembly 120 can be a laser of different wavelengths, or it can be white light. The design of the optical path system 130 can be flexibly designed according to the needs of the optical signal to be detected, for example, it can include a combination of multiple lens groups or optical elements, and it can also include an optical component that generates interference. The optical signal 10 to be detected can be a transmitted light signal, a reflected light signal, an interference light signal, or any light signal that can be used to detect wafer performance parameters. For example, by using light sources of different wavelengths, optical signals to be detected (such as interference light signals) with different phase shift amounts are obtained, and by analyzing the optical signals to be detected, performance parameters such as wafer thickness, stress, and warpage can be obtained.

[0026] Continue to refer Figure 1 , the detection device 100 may further include a detection system 140. The detection system 140 may include a first channel 141 and a second channel 142, the first channel 141 receives the optical signal 10 to be detected to obtain a first optical signal 11 of the wafer 110 at a first resolution, and the second channel 142 receives the optical signal 10 to be detected to obtain a second optical signal 12 of the wafer 110 at a second resolution. The first resolution is greater than the second resolution, so that different channels can receive optical signals of wafers with different resolutions to meet the detection requirements of wafers with different resolutions.

[0027] Continue to refer Figure 1 The detection device 100 may further include an optical path adjustment module 150, which is used to adjust the transmission direction of the optical signal 10 to be detected, so that the first channel 141 and the second channel 142 receive the optical signal 10 to be detected. That is, after the optical signal 10 to be detected passes through the optical path system 130, its transmission direction is adjusted by the optical path adjustment module 150, and then received by the first channel 141 and the second channel 142, thereby obtaining optical signals of wafers with different resolutions.

[0028] The addition of the optical path adjustment module enables the detection of wafers with different resolutions in the same detection equipment, which is conducive to the spatial multiplexing of different resolutions, thereby improving the flexibility and diversity of wafer detection and facilitating the rapid switching of detection needs. By setting at least two detection channels with different resolutions, it is conducive to real-time and rapid acquisition of the performance parameters of the wafer at different resolutions. In addition, since the same optical path system is reused without the need to set up two independent optical path systems, it not only helps to reduce detection costs and save space, but also helps to improve the accuracy and consistency of detection results of different detection channels. Compared with detection equipment with a single detection channel, it is conducive to enhancing the adaptability and functionality of the detection equipment, improving the detection efficiency of the detection equipment, and will not increase the complexity of the detection equipment too much due to the addition of detection channels, nor will it sacrifice the accuracy of the detection. Through this multi-channel design, the needs of comprehensive monitoring of overall performance parameters and local precise detection can be better met, which is conducive to providing more comprehensive and accurate detection results, thereby improving the overall detection performance and reliability.

[0029] It should be noted that the first optical signal and the second optical signal can be optical signals to be detected, or optical signals to be detected that are amplified at different magnifications, as long as the resolution of the first optical signal is greater than the resolution of the second optical signal. Correspondingly, for the first channel and the second channel, illustratively, the first channel 141 can be a high-resolution channel, suitable for focusing on precise measurement of local fine structures, and the second channel 142 can be a low-resolution channel, suitable for quickly overviewing the overall performance of the wafer. This flexible switching mechanism greatly improves the detection efficiency and reduces unnecessary repeated detection steps. Of course, the detection system can set multiple channels according to detection needs.

[0030] The optical path adjustment module can be flexibly selected according to the detection requirements. For example, the optical signal to be detected can be received by the first channel 141 and the second channel 142 in a time-sharing manner (refer to Figure 1 and Figure 5 ); It is also possible to make the optical signal to be detected be received simultaneously by the first channel 241 and the second channel 242 according to a certain ratio, direction or wavelength selection (reference Figure 2 ).

[0031] refer to Figure 1 and Figure 5 The optical path adjustment module may include a deflecting mirror assembly 150. After the optical signal 10 to be detected passes through the deflecting mirror assembly 150, it is received by the first channel 141 or the second channel 142. That is, after the optical signal 10 to be detected passes through the optical path system 530 and the deflecting mirror assembly 550, it is received by the first channel 541 and the second channel 542 in a time-sharing manner.

[0032] It can be understood that the position and angle of the deflection mirror assembly can be rotated or adjusted to guide the optical signal to be detected to be received by the first channel or the second channel, thereby flexibly switching the receiving channel. Due to the mechanical stability, easy adjustment and low energy loss of the deflection mirror assembly, the introduction of the deflection mirror assembly is conducive to improving the maintainability and reliability of the detection equipment.

[0033] As an example, see Figure 5 When the deflecting mirror assembly 550 is located at the first position A1, the first channel 541 receives the amplified optical signal 10 to be detected, and when the deflecting mirror assembly 550 is located at the second position A2, the second channel 542 receives the optical signal 54 to be detected, thereby realizing switching between different channels.

[0034] There are many ways to control the position and angle switching of the deflection mirror assembly, for example, it can be achieved through mechanical means, electrical means or algorithm control. These implementation methods have the advantages of simple operation and easy implementation.

[0035] It should be noted that the first position and the second position of the deflecting mirror assembly can be designed according to different optical path systems, for example, Figure 5 The up and down movement in the optical path may also be rotation or other methods, as long as the switching of the switching channel can be achieved. In addition, the relative position of the first channel and the second channel can be determined according to the requirements of the optical path design. For example, referring to Figure 5 , the first channel 541 and the second channel 542 can be arranged vertically; Figure 2 The first channel 241 and the second channel 242 can be arranged in parallel; the positional relationship between different channels is not specifically limited here.

[0036] refer to Figure 3 , the first channel 31 may include a first imaging component 313 and a first sensor 311. The first imaging component 313 is used to amplify the optical signal 30 to be detected into a third optical signal 33. For example, the first sensor 311 may receive the third optical signal 33 of a part of the wafer 110. The second channel 32 may include a second imaging component and a second sensor 312. The second imaging component is used to focus the optical signal 30 to be detected to obtain the optical signal to be detected at a second resolution. For example, it may receive the fourth optical signal 34 of the entire wafer 110 (i.e., wafer full-aperture measurement). Reference Figure 6 The first channel may further include a relay component 61, which may be located before the first imaging component and is used to transmit the optical signal to avoid large losses and changes during the transmission process.

[0037] It can be understood that by adding the first imaging component to the first channel, local high-resolution detection of the wafer can be simply and conveniently achieved without the need to purchase additional independent high-precision detection equipment, thereby helping to reduce detection costs. By adding a relay component, it is helpful to ensure that the optical signal to be detected remains consistent during the transmission process.

[0038] It is worth noting that there are many ways to implement the relay component, such as a telecentric optical system, a double telecentric optical system, etc., which are not specifically limited here. Figure 7 The relay assembly 71 may include an objective optical assembly 711 (close to the deflection mirror assembly 750) and an eyepiece optical assembly 712 (far away from the deflection mirror assembly 750) arranged in sequence from the entrance pupil to the exit pupil, the entrance pupil is located at the front focal plane of the objective optical assembly, the exit pupil is located at the back focal plane of the eyepiece optical assembly, and the back focus of the objective optical assembly coincides with the front focus of the eyepiece optical assembly. The objective optical assembly is used to collect the incident light beam, and the eyepiece optical assembly is used to collimate the incident light beam passing through the objective optical assembly. The optical power of the objective optical assembly is The optical power of the eyepiece optical assembly is The following relations are satisfied: and This design is conducive to improving the entrance pupil distance and exit pupil distance, so that optical elements of different sizes and quantities can be added before and after the optical relay assembly more flexibly, and it is conducive to reducing the tolerance requirements of processing and assembly, thereby reducing the difficulty of processing and installation, and also helping to reduce the difficulty of controlling optical distortion.

[0039] It should be noted that there are many ways to implement the first imaging component, for example, it can be a lens component, or it can be a telescope system or other imaging components. The magnification of the first imaging component can be flexibly designed according to the detection needs, for example, it can be 2 times, 5 times, 10 times, 20 times, etc., to achieve high-resolution detection of the first channel less than 10μm. Moreover, the magnification of the first imaging component can be either a specific magnification or continuously adjustable. The adjustment of the magnification can be achieved manually or automatically. The resolution of the first channel can achieve a resolution adjustment of 3 to 10μm, which can be adjusted continuously or set individually, such as 1μm, 3μm, 4μm, 5μm, 7μm, 10μm, and of course it can also be greater than 10μm, for example, it can be 20μm. The resolution of the second channel can be greater than 10μm (a specific resolution can be set as needed), for example, it can be 45μm, 60μm, etc.

[0040] refer to Figure 5In order to cooperate with the first imaging component and not be limited by the receiving capacity of the first sensor, the first channel 541 can also include a driving device for moving the position of the first sensor 52 to obtain the third light signal 53 amplified by the first imaging component 51.

[0041] By providing the driving device, the first sensor can flexibly, accurately and quickly obtain the third optical signal 53 at any local position of the wafer, thereby achieving more comprehensive and accurate collection of wafer optical signals.

[0042] There are many ways to implement the driving device, for example, it can be implemented through mechanical, electronic or algorithm control, which is not specifically limited here.

[0043] In order to further improve the accuracy and flexibility of the first sensor reception, refer to Figure 4 and Figure 6 The first channel may further include a beam deflection component 441 for scanning and positioning any position of the wafer 110 so that the third optical signal 45 amplified by the first imaging component 443 is received by the first sensor 442 without moving the position of the wafer.

[0044] by Figure 6 For example, after the optical signal 10 to be detected enters the first channel 641, it passes through the relay component 61, is reflected by the beam deflection component 63, is amplified by the first imaging component 62 into a third optical signal 10', and is received by the first sensor 66. And / or after the optical signal 10 to be detected enters the second channel 642, it is amplified by the second imaging component 64 into a fourth optical signal 10" and is received by the second sensor 65.

[0045] By adjusting the position and angle of the beam deflection assembly, the first sensor can receive a high-resolution third optical signal at any position of the wafer without changing the position of the wafer. This not only helps to improve the accuracy of the first sensor, but also helps to simplify the structure of the detection equipment, making the operation more convenient and easy to control. This is conducive to flexibly and efficiently acquiring optical signals at any position of the wafer, providing convenience for high-resolution detection.

[0046] It should be noted that there are many ways to achieve precise control of the position and angle of the beam deflection component, such as an electromagnetic drive, a piezoelectric drive or any other form, which is not specifically limited here.

[0047] Exemplarily, the beam deflection assembly can be a beam scanning assembly. By quickly and accurately moving the beam, it is helpful to scan different positions of the wafer without moving the wafer and the first sensor, reducing the error caused by the movement process, thereby helping to improve the accuracy and detection efficiency of the detection equipment. There are many types of beam scanning assemblies, such as two mutually perpendicular one-dimensional scanning galvanometers, a two-dimensional scanning galvanometer, a fully solid-state optical beam two-dimensional scanner, etc., as long as the transmission direction of the beam can be changed, there is no specific limitation here.

[0048] refer to Figure 8 Taking the beam deflection component as two mutually perpendicular first scanning galvanometer mirrors 831 and second scanning galvanometer mirrors 832 as an example, it is explained that the beam deflection component can realize scanning and positioning of any position of the wafer 110, so that the third optical signal 85 is received by the first sensor 82.

[0049] For ease of understanding, various directions are indicated by arrows in the disclosure, wherein arrow X+ points to one side of a first direction, arrow X- points to the other side of the first direction, arrow Y+ points to one side of a second direction, and arrow Y- points to the other side of the second direction.

[0050] Continue to refer Figure 8 The first scanning galvanometer 831 may include a first support frame 8311 and a first reflector 8312 , and the first support frame 8311 is used to fix the first reflector 8312 to ensure the stability of the first reflector 8312 during operation.

[0051] The first reflector 8312 can move along the first direction and rotate around the first direction driven by the first support frame 8311. The second scanning galvanometer 832 may include a second support frame 8321 and a second reflector 8322, and the second support frame 8321 is used to fix the second reflector 8322 to ensure the stability of the second reflector 8322 during operation. The second reflector 8322 can move along the second direction and rotate around the second direction driven by the second support frame 8321. The first support frame 8311 and the second support frame 8321 are arranged vertically, and the first support frame 8311 and the second support frame 8321 are driven by the control system to drive the movement of the first reflector 8312 and the second reflector 8322, so as to realize the positioning and scanning of any position and any scanning mode of the wafer. This implementation method has the advantages of strong operability and easy control.

[0052] return Figure 2 The optical path adjustment module may also include a beam splitter component 250. After the optical signal 10 to be detected passes through the beam splitter component 250, it is split into a first optical signal 21 and a second optical signal 22, and is received by the first channel 241 and the second channel 242 at the same time.

[0053] It can be understood that by arranging the beam splitter assembly 250 at the third position A3, the optical signal 10 to be detected can be split into two or more independent optical signals, and the light is usually split according to a specific ratio, direction or wavelength according to certain rules and optical principles. For example, it can be a beam splitter plate (realized by a beam splitter film on a beam splitting surface), a power beam splitter, a prism beam splitter, or a half-reflecting half-mirror, as long as the optical signal to be detected can be split into two or more independent optical signals.

[0054] By adding a beam splitter component, the detection system achieves spatial and temporal multiplexing of the wafer, and can detect the performance parameters of one side of the wafer at different resolutions without using two sets of detection equipment. This allows the collection of high-resolution optical signals at different positions on the wafer to be achieved within the same system, thus helping to improve the detection efficiency of large-size wafers, reduce detection costs, and maximize resource utilization.

[0055] The detection device may also include a controller for controlling the optical path system to generate an optical signal to be detected for the wafer according to a control instruction, and adjusting the position of the optical path adjustment module so that the first sensor in the first channel of the detection system receives the optical signal to be detected to obtain the first optical signal at a first resolution, and / or the second sensor in the second channel of the detection system receives the optical signal to be detected to obtain the second optical signal at a second resolution. The controller is also used to process the first optical signal and the second optical signal to obtain the performance parameters of the wafer. The controller can also be used to modulate the wavelength of the laser in the light source assembly to obtain interference signals with different phase shift amounts. Based on the collected multiple interference optical signals with different phase shifts, the morphological parameters of the wafer are obtained through a specific algorithm.

[0056] It should be noted that the phase shift control system obtains interference signals with different phase shift amounts by modulating the wavelength of the laser in the light source assembly. Based on the collected multiple interference light signals with different phase shifts, the morphological parameters of the wafer are obtained through a specific algorithm. Of course, the phase shift system can also generate interference signals with different phase shift amounts by adjusting the distance between the standard mirror assembly and the wafer. It should be noted that in the interference signal generated by the phase shift control system, the phase shift amount of the two adjacent interference images is an integer multiple of pi / 16 (a phase shift amount of 2pi corresponds to a complete interference fringe movement cycle). Fig. 9 A detection method suitable for wafer detection provided by an embodiment of the present invention is shown.

[0057] Step S10, controlling the optical path system to generate an optical signal to be detected for the wafer according to the control instruction, and adjusting the position of the optical path adjustment module so that the first sensor in the first channel of the detection system receives the optical signal to be detected to obtain the first optical signal at a first resolution, and / or the second sensor in the second channel of the detection system receives the optical signal to be detected to obtain the second optical signal at a second resolution.

[0058] Step S11, the optical path adjustment module is a deflection mirror assembly, and the position of the optical path adjustment module is adjusted, including: controlling the deflection mirror assembly to be located at a first position so that the first sensor receives a first light signal at a first resolution; controlling the deflection mirror assembly to be located at a second position so that the second sensor receives a second light signal at a second resolution.

[0059] The optical path adjustment module may be a beam splitter component, and adjusting the position of the optical path adjustment module includes: controlling the beam splitter component to be located at a third position, and obtaining performance parameters of the wafer according to the first optical signal and the second optical signal.

[0060] Step S12, instructing the beam deflection assembly to scan the wafer according to the control instruction, so that the first sensor receives the third light signal at any position of the wafer.

[0061] It should be noted that the beam deflection assembly is used to adjust the transmission direction of the first optical signal to achieve scanning of any position of the wafer. Preferably, the beam deflection assembly may include a beam scanning assembly, such as two mutually perpendicular one-dimensional scanning galvanometers, a two-dimensional scanning galvanometer, and a fully solid-state optical beam two-dimensional scanner. The control instruction includes scanning parameters and scanning modes of the beam deflection assembly.

[0062] For example, the beam deflection component is two mutually perpendicular one-dimensional scanning galvanometers as an example for specific description, refer to Figure 8 , the control instruction instructs the first scanning galvanometer 831 to move in the first direction and rotate around the first direction, and at the same time instructs the second scanning galvanometer to move in the second direction and rotate around the second direction, so that the first light signal passing through the relay component is reflected by the first scanning galvanometer and the second scanning galvanometer, amplified by the first imaging component into a third light signal, and then received by the first sensor. At this time, the second sensor receives the second light signal after passing through the second imaging component. The addition of the relay component is conducive to ensuring that the light signal entering the movable scanning galvanometer is as consistent as possible with the light signal passing through the deflection mirror assembly.

[0063] Step S20, processing the third optical signal and the second optical signal to obtain performance parameters of the wafer.

[0064] It can be understood that the controller calculates and analyzes the third light signal and the second light signal to obtain parameter values ​​such as the thickness, stress or warpage of the wafer. For example, the third light signal or the second light signal is an interference light signal, and the performance parameters of the wafer at different resolutions are obtained by analyzing the spacing, inclination and other values ​​between the fringes in the interference light signal. Of course, there are many technical methods for obtaining performance parameters, which are not specifically limited here. In some examples, by modulating light source components of different wavelengths, interference light signals with different phase shifts are obtained (for example, the phase shift of two adjacent interference images is an integer multiple of pi / 16), and the morphological parameters of the wafer are obtained based on the collected multiple interference light signals with different phase shifts through a specific algorithm.

[0065] For ease of understanding, the following Figure 7 Taking the optical path system to generate interference light signals as an example, the structure and detection process of the detection equipment are briefly described.

[0066] The detection device 700 may include a light source assembly 120 , an optical path system 730 , a deflecting mirror assembly 750 , and a detection system 740 .

[0067] The optical path system 730 may include a standard mirror assembly 74, a collimation and collection assembly 75, a quarter wave plate assembly 76, a polarization beam splitter assembly 77, and an aperture assembly 78, which are used to generate interference light signals to enter the deflection mirror assembly 750. The distance between the reference standard mirror and the wafer is less than 50 mm, and of course the smaller the distance between them, the better, which also needs to be determined according to the design of the optical path.

[0068] The detection system 740 may include a first channel 742, a second channel 741 and a phase shift control system. The first channel 742 may include a relay component 71, a movable scanning galvanometer 73, a first imaging component 72 and a first sensor 79. The second channel 742 may include a second imaging component 81 and a second sensor 80. When the deflection mirror assembly 750 is located at the fourth position B1, the light signal to be detected is received by the first channel 742, and when the deflection mirror assembly 750 is located at the fifth position B2, the interference light signal is received by the second channel 741. Among them, AA represents a cross-sectional view of the light beam scanning component in the actual light path along the direction perpendicular to the paper surface. Of course, the optical path system may also have only one detection channel, which is not specifically limited here.

[0069] The overall wafer (second channel, i.e. low-resolution channel) inspection process is as follows:

[0070] Input the control command of the overall detection, the controller adjusts the distance between the wafer and the standard mirror to the standard distance (less than 50mm), and adjusts the deflection mirror assembly 750 to the fifth position B2, the light source assembly 120 irradiates the wafer 110 through the polarization beam splitter assembly 77 and is reflected, and the reflected light passes through the collimation assembly 75, the 1 / 4 wave plate assembly 76, the polarization beam splitter assembly 77 and the aperture assembly 78 in sequence, and forms an interference light signal with the light beam reflected by the standard mirror 74, that is, the light signal to be detected. After the interference light signal passes through the deflection mirror assembly 750, it is received by the second sensor of the second channel through the second imaging assembly, and the controller modulates different wavelengths to obtain interference light signals with different phase shift amounts. By calculating and analyzing the interference light signals with different phase shift amounts received by the second sensor, the thickness, warpage, stress and other parameters of the entire wafer are obtained.

[0071] The local (first channel, i.e. high-resolution channel) inspection process of the wafer is as follows:

[0072] Input the control command of local detection, adjust the deflection mirror assembly 750 to the fourth position B1, and the interference light signal generated during the overall detection process passes through the deflection mirror assembly 750, passes through the relay assembly 71 and the movable scanning galvanometer 73, and the position and angle of the movable scanning galvanometer scan the local part of the wafer according to the instruction of the controller. The scanned light signal passes through the first imaging assembly 72 and can be received by the first sensor 79, thereby obtaining a high-resolution interference light signal at any position on the wafer 110, and the local warpage, stress and other parameters of the wafer are obtained through analysis and calculation. And through multiple continuous scanning, a high-resolution overall image of the wafer is obtained.

[0073] Of course, according to the detection needs, the second channel can also be provided with a beam deflection component. As an example, for a wafer of 300mm*300mm size, different modes of scanning are required according to the detection needs. By inputting control instructions of different scanning modes, the first scanning galvanometer and the second scanning galvanometer scan according to specific scanning parameters and scanning modes. Among them, the scanning parameters may include the scanning speed, scanning range, scanning frequency, etc., and the scanning mode may include the scanning direction, scanning path, etc. The scanning path can select the Lissajou curve (reference Fig.10a ), spiral curve (reference Fig.10b ), hexagon (reference Fig.10c ), quadrilateral (reference Fig.10d ), etc. Of course, the scanning path can also be edited as needed.

[0074] For example, for a wafer of 300 mm*300 mm size, the overall image of the wafer can also be obtained by multiple local scans. Moreover, for high-resolution scanning, the number of scans is calculated according to the resolution. Fig.11 , the area of ​​each scan is 35mm*47mm, and at least 300*300 / (35*47)≈55 scans are required to obtain the overall optical signal of the wafer at high resolution. If 20% coverage is required (i.e. 20% of the edge is shared), at least 300*300 / (35*47*80%)≈70 scans are required to obtain the overall image of the wafer at high resolution.

[0075] It should be noted that the devices with different numbers in the aforementioned figures may refer to devices with the same function, which may be adaptively adjusted according to actual needs in practical applications.

[0076] It should be understood that although the terms "first" or "second" etc. may be used to describe various elements (such as a first channel and a second channel) in embodiments of the present invention, these elements are not defined by these terms, which are only used to distinguish one element from another.

[0077] It should be noted that the accompanying drawings are merely examples and are not limitations on the structure of the optical path diagram, wherein the various optical path schematic diagrams may be in a parallel relationship or a progressive relationship, may be combined with each other, or the optical path units in the various optical path schematic diagrams may also be combined with reference to each other. In order to avoid unnecessary repetition, the present invention will not further explain various possible combinations.

[0078] In the several embodiments provided in the present application, it should be understood that the disclosed systems and devices can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units or modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of units or modules can be electrical or other forms.

[0079] In addition, each functional unit or module in each embodiment of the present application may be integrated into one processing unit or module, or each unit or module may exist physically separately, or two or more units or modules may be integrated into one unit or module.

[0080] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be conceived by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A testing device for testing wafers, characterized in that: include: Light source assembly; An optical path system, used for guiding the light source assembly to irradiate the wafer to generate a light signal to be detected; The detection system comprises a first channel and a second channel, wherein the first channel receives the optical signal to be detected to obtain a first optical signal of the wafer at a first resolution, and the second channel receives the optical signal to be detected to obtain a second optical signal of the wafer at a second resolution; An optical path adjustment module, used for adjusting the transmission direction of the optical signal to be detected so that the first channel and the second channel receive the optical signal to be detected; The first resolution is greater than the second resolution.

2. The detection device according to claim 1, characterized in that: The optical path adjustment module includes a deflecting mirror assembly. After the optical signal to be detected passes through the deflecting mirror assembly, it is received by the first channel and the second channel.

3. The detection device according to claim 2, characterized in that: When the deflecting mirror assembly is located at a first position, the first channel receives the optical signal to be detected, and when the deflecting mirror assembly is located at a second position, the second channel receives the optical signal to be detected.

4. The detection device according to claim 1, characterized in that: The first channel includes a first imaging component and a first sensor, the first imaging component is used to amplify the light signal to be detected into a third light signal so that the first sensor receives the third light signal locally on the wafer, and the second channel includes a second sensor for receiving a fourth light signal on the entire wafer.

5. The detection device according to any one of claims 4, characterized in that: The first channel also includes a beam deflection component for scanning and positioning any position of the wafer so that the third optical signal is received by the first sensor.

6. The detection device according to claim 5, characterized in that: The beam deflection assembly includes a beam scanning assembly.

7. The detection device according to claim 6, characterized in that: The light beam scanning assembly includes a first scanning galvanometer and a second scanning galvanometer that are perpendicular to each other and are used to scan and position any position of the wafer so that the third light signal is received by the first sensor.

8. The detection device according to claim 1, characterized in that: The optical path adjustment module includes a beam splitter component. After the optical signal to be detected passes through the beam splitter component, it is received by the first channel and the second channel to obtain the first optical signal of the wafer at the first resolution and the second optical signal at the second resolution.

9. The detection device according to claim 1, characterized in that: The optical signal to be detected is an interference optical signal.

10. The detection device according to claim 1, characterized in that: Also includes: A controller is used to control the optical path system to generate an optical signal to be detected for the wafer according to a control instruction, and adjust the position of the optical path adjustment module so that the first sensor in the first channel of the detection system receives the optical signal to be detected to obtain a first optical signal at a first resolution, and / or the second sensor in the second channel of the detection system receives the optical signal to be detected to obtain a second optical signal at a second resolution. The controller is also used to process the first optical signal and the second optical signal to obtain performance parameters of the wafer.

11. A detection method for detecting a wafer, characterized in that: include: Controlling the optical path system to generate an optical signal to be detected for the wafer according to the control instruction, and adjusting the position of the optical path adjustment module so that a first sensor in a first channel of the detection system receives the optical signal to be detected to obtain a first optical signal at a first resolution, and / or a second sensor in a second channel of the detection system receives the optical signal to be detected to obtain a second optical signal at a second resolution; Processing the first optical signal and the second optical signal to obtain performance parameters of the wafer; The first resolution is greater than the second resolution.

12. The detection method according to claim 11, characterized in that: The optical path adjustment module is a deflection mirror assembly, and the step of adjusting the position of the optical path adjustment module includes: The deflecting mirror assembly is controlled to be located at a first position so that the first sensor receives a first light signal at a first resolution; the deflecting mirror assembly is controlled to be located at a second position so that the second sensor receives a second light signal at a second resolution.

13. The detection method according to claim 11, characterized in that: The optical path adjustment module is a beam splitter component, and adjusting the position of the optical path adjustment module includes: The beam splitter assembly is controlled to be located at a third position, and a performance parameter of the wafer is obtained according to the first optical signal and the second optical signal.

14. The detection method according to claim 12, characterized in that: Also includes: The light beam deflection assembly is instructed to scan the wafer according to the control instruction, so that the first sensor receives the third light signal at any position of the wafer.

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