Wafer warping monitoring device and method and wafer manufacturing system
Monitoring wafer warpage through laser self-interference technology solves the problems of insufficient detection accuracy and high implementation difficulty in existing technologies, realizes efficient and high-precision wafer warpage monitoring, reduces equipment complexity and damage risk, and improves process yield.
Patent Information
- Application Number
- CN202510799227.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-09-05
AI Technical Summary
In the existing technology, the accuracy of wafer warpage detection is insufficient and the implementation is difficult, making it difficult to effectively apply in actual production, resulting in wafer damage and reduced process yield.
Laser self-interference technology is used to obtain the light intensity data of the interfering laser light through the interference of forward and reverse laser light, calculate the wafer warpage data, and use laser detection devices to detect the changes in light and dark stripes after interference to achieve high-precision warpage monitoring.
The accuracy and efficiency of wafer warpage monitoring are improved, wafer breakage is reduced, process yield is improved, structure is simplified and equipment complexity is reduced.
Smart Images
Figure CN120600652A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a wafer warpage monitoring device, method, and wafer manufacturing system. Background Art
[0002] During the wafer manufacturing process, the degree of wafer warpage is usually detected using laser ranging technology or by setting specific patterns on the wafer. However, this method has insufficient detection accuracy. Conventional interferometry can also be used to monitor the degree of wafer warpage, but this method is difficult to implement and the system is complex, making it difficult to use smoothly in actual production.
[0003] Therefore, regarding the detection of wafer warpage, the field urgently needs to provide a method with a simple structure, easy installation, and high efficiency and high precision to quantify the difference in wafer warpage under different adsorption forces during the process, thereby reducing wafer damage and improving process yield. Summary of the Invention
[0004] Based on this, it is necessary to provide a wafer warpage monitoring device, method and wafer manufacturing system to address the above-mentioned technical problems.
[0005] The present application provides a wafer warpage monitoring device, which includes:
[0006] A laser emitting device, the laser emitting device being configured to emit a forward laser beam and a reverse laser beam, wherein the forward laser beam is configured to be projected toward a surface of a target wafer and reflected by the surface of the target wafer to form a forward reflected laser beam, wherein the reverse laser beam and the forward reflected laser beam interfere with each other to form an interference laser beam;
[0007] A laser detection device is used to receive the interfering laser light and obtain light intensity data of the interfering laser light, and the light intensity data is used to calculate wafer warpage data of a target wafer.
[0008] In one embodiment, the wafer warpage data is calculated based on the following formula:
[0009]
[0010] Wherein, d is the wafer warpage data, λ is the wavelength data of the interference laser light, and N is the light intensity data; and / or,
[0011] The forward laser light is projected vertically toward the surface of the target wafer.
[0012] In one embodiment, the light intensity data includes the number of times the interference fringes of the interfering laser light change from bright to dark.
[0013] In one embodiment, the light intensity data includes a plurality of intensity values, the plurality of intensity values including a plurality of maximum intensity values and a plurality of minimum intensity values, and the sum of the number of the maximum intensity values and the number of the minimum intensity values is N;
[0014] The N value after the target wafer is deformed is set to N1, and the N value before the target wafer is deformed is set to N2. The difference between N1 and N2 is the number of light and dark changes of the interference fringes.
[0015] In one embodiment, the laser emitting device includes:
[0016] A device body, wherein the device body has a main body cavity therein, and the device body is provided with a forward emission window and a reverse emission window communicating with the main body cavity;
[0017] an excitation source, the excitation source being disposed in the main body chamber and being used to generate a laser light source;
[0018] An optical medium, wherein the optical medium is disposed in the main body chamber, and the laser light source is formed through the optical medium to emit the forward laser light and the reverse laser light in different directions;
[0019] An optical reflection component is arranged in the main body cavity, the forward laser light is projected from the forward emission window through the optical reflection component, the reverse laser light is projected from the reverse emission window through the optical reflection component, and the forward reflected laser light is projected from the reverse emission window through the forward emission window and the optical reflection component.
[0020] In one embodiment, the optical reflective component includes:
[0021] a first reflecting element, wherein the first reflecting element is disposed in the main body chamber, and the forward laser light is projected from the forward emission window through the first reflecting element;
[0022] a second reflecting element, the second reflecting element being disposed in the main body chamber, and the reverse laser light being projected from the reverse emission window via the second reflecting element;
[0023] The forward reflected laser light is projected out from the backward emitting window through the forward emitting window, the second reflecting element and the first reflecting element.
[0024] In one embodiment, the optical reflective component includes:
[0025] a third reflecting element, the third reflecting element being disposed in the main body chamber, and the forward laser light being projected from the forward emission window via the third reflecting element;
[0026] a fourth reflecting element, the fourth reflecting element being disposed in the main body chamber, and the reverse laser light being projected from the reverse emission window via the fourth reflecting element;
[0027] A fifth reflecting element is provided in the main body chamber, and the forward reflected laser light is projected from the reverse emitting window through the forward emitting window, the fourth reflecting element and the fifth reflecting element.
[0028] The present application provides a wafer manufacturing system, comprising:
[0029] Wafer carrier;
[0030] A support member, the support member being disposed on the wafer carrying device, the support member being configured to carry a target wafer, wherein the support member has an opening for passing a forward laser beam and a forward reflected laser beam;
[0031] A gas spray device, the gas spray device is arranged opposite to the wafer carrying device,
[0032] The wafer warpage monitoring device is arranged on the gas spraying device.
[0033] The present application provides a wafer warpage monitoring method, which comprises the following steps:
[0034] Emitting forward laser light and reverse laser light;
[0035] Projecting the forward laser light onto the surface of the target wafer to reflect the forward laser light from the surface of the target wafer, and controlling the forward reflected laser light and the reverse laser light to interfere with each other to form an interference laser light;
[0036] Light intensity data of the interfering laser light is acquired, and wafer warpage data of the target wafer is calculated based on the light intensity data.
[0037] In one embodiment, the wafer warpage data is calculated based on the following formula:
[0038]
[0039] Wherein, d is the wafer warpage data, λ is the wavelength data of the interference laser light, N is the light intensity data, and the light intensity data includes the number of light and dark changes of the interference fringes of the reverse laser light and the forward reflected laser light; and / or,
[0040] At different times, light intensity data of the interfering laser light is acquired at least twice for the same point on the surface of the target wafer, and wafer warpage data at different times for the same point is acquired.
[0041] During the wafer warpage monitoring process, the above-mentioned wafer warpage monitoring device measures the accuracy of the laser wavelength used, i.e., the wavelength of the forward laser light and the reverse laser light. This wavelength is typically in the order of hundreds of nanometers. In special circumstances, the laser phase can be calibrated to improve the accuracy to the nanometer level. Furthermore, the above-mentioned monitoring method utilizes laser self-interference technology to monitor the difference in wafer warpage under different processes in situ and online. That is, by detecting the changes in light and dark fringes after interference by a laser detection device, the warpage deformation of the wafer can be conveniently monitored. The performance requirements for the laser detection device are low, and basically any instrument that can determine the light intensity can be used. Compared with conventional interference technology, it has the advantages of a simple optical path, a simple structure, and easy installation. This ensures efficient and high-precision quantification of the difference in wafer warpage under different adsorption forces during the process, and then uses this as a basis to appropriately adjust the adsorption force provided by the adsorption system, avoiding back plating and damage problems caused by a mismatch between the actual adsorption force provided and the adsorption force required by the wafer process, thereby improving the yield and reducing wafer damage. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 A schematic diagram of the light projection path of a wafer warpage monitoring device provided in one embodiment of the present application.
[0043] Figure 2 A schematic diagram of the light projection path of a wafer warpage monitoring device provided in another embodiment of the present application.
[0044] Figure 3 This is a schematic diagram of the usage status of the wafer warpage monitoring device provided in one embodiment of the present application.
[0045] Figure 4 For example Figure 3 The figure shows a top view of the wafer warpage monitoring device in use.
[0046] Figure 5 This is a schematic diagram of the usage status of a wafer warpage monitoring device provided in another embodiment of the present application.
[0047] Figure 6 For example Figure 5 The figure shows a top view of the wafer warpage monitoring device in use.
[0048] Figure 7 This is a top view of a wafer warpage monitoring device in use provided in yet another embodiment of the present application.
[0049] Figure 8 This is a schematic diagram of interference fringes provided in one embodiment of the present application.
[0050] Figure Number:
[0051] 100, target wafer; 200, gas spray device; 210, gas flow hole; 300, wafer carrying device; 310, support member;
[0052] 1000, laser emitting device; 2000, laser detecting device;
[0053] 1100, excitation source; 1200, optical medium; 1310, first reflective element; 1320, second reflective element; 1330, third reflective element; 1340, fourth reflective element; 1350, fifth reflective element;
[0054] 1000a, forward laser light; 1000b, reverse laser light; 1000c, forward reflected laser light. DETAILED DESCRIPTION
[0055] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.
[0056] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.
[0057] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.
[0058] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.
[0059] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.
[0060] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.
[0061] like Figures 1 to 7 As shown, the present application provides a wafer warpage monitoring device, which includes a laser emitting device 1000 and a laser detection device 2000. The laser emitting device 1000 can be a ruby laser, a semiconductor laser, a fiber laser, a YAG laser, etc. The laser detection device 2000 can be a photometer, a photocell, a CCD camera, a spectrometer, a spectrometer, etc.
[0062] The laser emitting device 1000 is used to emit a forward laser beam 1000a and a reverse laser beam 1000b. A wafer warpage monitoring device can be positioned at an appropriate location on the target wafer 100 according to monitoring requirements, so that the forward laser beam 1000a can be projected toward the surface of the target wafer 100 and reflected from the surface of the target wafer 100 to form a forward reflected laser beam 1000c. For example, the forward laser beam 1000a is projected in a direction perpendicular to the surface of the target wafer 100, such as being projected perpendicularly toward the surface of the target wafer 100. Upon reaching the surface of the target wafer 100, the forward laser beam 1000a can be reflected in a substantially opposite direction to form the aforementioned forward reflected laser beam 1000c. The reflection direction of the forward reflected laser beam 1000c depends on the flatness of the surface of the target wafer 100.
[0063] Laser detection device 2000 is used to receive reverse laser light 1000b and forward reflected laser light 1000c. Its primary function is to obtain light intensity data resulting from the interference between reverse laser light 1000b and forward reflected laser light 1000c. Reverse laser light 1000b and forward reflected laser light 1000c are configured to interfere with each other to form interfering laser light. Therefore, laser detection device 2000 primarily functions to obtain light intensity data from the interfering laser light.
[0064] The reverse laser beam 1000b and the forward reflected laser beam 1000c can reach the same point on the laser detection device 2000. This allows the laser detection device 2000 to detect the interference between the reverse laser beam 1000b and the forward reflected laser beam 1000c, and obtain intensity data of the interference. This intensity data is used to calculate the wafer warpage data of the target wafer 100.
[0065] The calculation principle is that when the wafer warps, the optical path of the forward laser beam 1000a changes, which in turn changes the forward reflected laser beam 1000c. This, in turn, causes a change in the intensity of the forward reflected laser beam 1000c received by the laser detection device 2000. This change in light intensity can be used to calculate the degree of wafer warpage.
[0066] Regarding calculating the wafer warpage data of the target wafer 100 , in one embodiment, the wafer warpage data may be calculated based on the following formula:
[0067]
[0068] Wherein, d is the wafer warpage data, λ is the wavelength data of the reverse laser light 1000b and the forward reflected laser light 1000c, and N is the light intensity data.
[0069] In the above formula, the wavelength data can be measured based on different types of lasers. Those skilled in the art can select an appropriate laser based on actual needs to determine the wavelength data of the corresponding laser. The intensity data can be determined as the number of bright and dark changes in the interference fringes between the reverse laser light 1000b and the forward reflected laser light 1000c.
[0070] Regarding the number of light and dark changes of the interference fringes, in one embodiment, the light intensity data obtained by the laser detection device 2000 may include a plurality of intensity values, wherein the plurality of intensity values may include a plurality of maximum intensity values and a plurality of minimum intensity values, see Figure 8 As shown, the maximum intensity value corresponds to a bright fringe, and the minimum intensity value corresponds to a dark fringe. At this point, the sum of the total number of maximum intensity values and the total number of minimum intensity values is set to N, and the N value after the target wafer 100 is deformed is set to N1, and the N value before the target wafer 100 is set to N2. The difference between N1 and N2 is the number of light and dark changes in the interference fringe, which is substituted into the above formula to calculate the wafer warpage data d. For the same point on the target wafer 100, the degree of wafer warpage at different times can be monitored and compared before and after. If a change occurs, it can be considered that the target wafer 100 has deformed and warped.
[0071] The laser emitting device 1000 and the laser detecting device 2000 can be set to mutually adapted positions and angles as required, thereby realizing the emission and reception of the forward laser light 1000a, the reverse laser light 1000b, and the forward reflected laser light 1000c, thereby achieving the above-mentioned purpose of monitoring the degree of wafer warpage. In one embodiment, the laser emitting device 1000 may include a device body, an excitation source 1100, an optical medium 1200, and an optical reflective component. The device body serves as the basis for assembly, and the interior of the device body may have a main body cavity, which can serve as an optical resonant cavity. At the same time, the device body is provided with a forward emission window and a reverse emission window connected to the main body cavity. The forward emission window and the reverse emission window can be used to project the forward laser light 1000a and the reverse laser light 1000b outward, respectively.
[0072] The excitation source 1100 is disposed in the main body chamber and is used to generate a laser light source. The optical medium 1200 is disposed in the main body chamber and is used to refract, reflect, and transmit light. When transmitting light, the optical medium 1200 can change the direction, intensity, and phase of the light so that the light is transmitted according to predetermined requirements. In the above-mentioned laser emitting device 1000, the laser light source generated by the excitation source 1100 can be formed into a forward laser light 1000a and a reverse laser light 1000b with different emission directions through the optical medium 1200. The forward laser light 1000a and the reverse laser light 1000b can be completely opposite or form a certain angle, as long as the formation of the forward reflected laser light 1000c and the reception of the light by the laser detection device 2000 are satisfied. No limitation is imposed here.
[0073] At this time, the optical reflection component is arranged in the main body cavity. Through the reasonable setting of the optical reflection component, the forward laser light 1000a can be projected from the forward emission window through the optical reflection component, the reverse laser light 1000b can be projected from the reverse emission window through the optical reflection component, and the forward reflected laser light 1000c can be reflected back through the forward emission window and then projected from the reverse emission window through the optical reflection component.
[0074] In the above process, the reverse laser light 1000b can be projected toward the laser detection device 2000 after being projected from the reverse emission window, and the forward reflected laser light 1000c can also be projected toward the laser detection device 2000 after being projected from the reverse emission window. The forward reflected laser light 1000c and the reverse laser light 1000b will interfere with each other when projected toward the laser detection device 2000, thereby enabling the laser detection device 2000 to obtain the light intensity data after the interference of the reverse laser light 1000b and the forward reflected laser light 1000c.
[0075] like Figure 1As shown, in one embodiment, the optical reflection assembly may include a first reflection element 1310 and a second reflection element 1320. The first reflection element 1310 is disposed in a main body chamber. By setting the position, angle, etc. of the first reflection element 1310, the forward laser light 1000a is projected from the forward emission window through the first reflection element 1310. The second reflection element 1320 is disposed in the main body chamber. Similarly, by setting the position, angle, etc. of the second reflection element 1320, the reverse laser light 1000b is projected from the reverse emission window through the second reflection element 1320. The forward reflected laser light 1000c is projected from the reverse emission window through the forward emission window, the second reflection element 1320, and the first reflection element 1310. That is, the forward reflected laser light 1000c is reflected back from the forward emission window and then sequentially passes through the second reflection element 1320 and the first reflection element 1310 to be projected from the reverse emission window.
[0076] In the above process, the reverse laser light 1000b can be projected toward the laser detection device 2000 after being projected from the reverse emission window, and the forward reflected laser light 1000c can also be projected toward the laser detection device 2000 after being projected from the reverse emission window. The forward reflected laser light 1000c and the reverse laser light 1000b will interfere with each other when projected toward the laser detection device 2000, thereby enabling the laser detection device 2000 to obtain the light intensity data after the interference of the reverse laser light 1000b and the forward reflected laser light 1000c.
[0077] like Figure 2 As shown, in one embodiment, the optical reflective component may include a third reflective element 1330 , a fourth reflective element 1340 and a fifth reflective element 1350 . The third reflecting element 1330 is arranged in the main body chamber, and the position, angle, etc. of the third reflecting element 1330 can be set so that the forward laser light 1000a can be projected from the forward emission window through the third reflecting element 1330. The fourth reflecting element 1340 is arranged in the main body chamber, and the position, angle, etc. of the fourth reflecting element 1340 can be set so that the reverse laser light 1000b can be projected from the reverse emission window through the fourth reflecting element 1340. The fifth reflecting element 1350 is arranged in the main body chamber, and the position, angle, etc. of the fifth reflecting element 1350 can be set so that the forward reflected laser light 1000c can be projected from the reverse emission window through the forward emission window, the fourth reflecting element 1340 and the fifth reflecting element 1350, that is, the forward reflected laser light 1000c is reflected back from the forward emission window, and then passes through the fourth reflecting element 1340 and the fifth reflecting element 1350 in sequence to be projected from the reverse emission window.
[0078] In the above process, the reverse laser light 1000b can be projected toward the laser detection device 2000 after being projected from the reverse emission window, and the forward reflected laser light 1000c can also be projected toward the laser detection device 2000 after being projected from the reverse emission window. The forward reflected laser light 1000c and the reverse laser light 1000b will interfere with each other when projected toward the laser detection device 2000, thereby enabling the laser detection device 2000 to obtain the light intensity data after the interference of the reverse laser light 1000b and the forward reflected laser light 1000c.
[0079] In addition, those skilled in the art may also construct the above-mentioned reflective components in other quantities and settings, so that the reflective components can control the projection paths of the forward laser light 1000a, the reverse laser light 1000b and the forward reflected laser light 1000c, so that the forward reflected laser light 1000c and the reverse laser light 1000b interfere with each other when projected toward the laser detection device 2000, which is not limited here.
[0080] During wafer warpage monitoring, the aforementioned wafer warpage monitoring device achieves measurement accuracy equal to the wavelength of the laser light used, namely, the wavelength of the forward laser beam 1000a and the reverse laser beam 1000b. This wavelength is typically in the order of hundreds of nanometers. Under special circumstances, laser phase calibration can be employed to improve accuracy to the nanometer level. Furthermore, the aforementioned monitoring method utilizes laser self-interference technology to in-situ monitor differences in wafer warpage under different process conditions. Specifically, laser detection device 2000 detects changes in light and dark fringes after interference, thereby conveniently monitoring wafer warpage. The performance requirements for laser detection device 2000 are low; essentially, any instrument capable of determining light intensity can be used. Compared to conventional interferometry techniques, the device offers advantages such as a simple optical path, a simplified structure, and ease of installation. This ensures efficient and high-precision quantification of differences in wafer warpage under different adsorption forces during the process. This allows for appropriate adjustment of the adsorption force provided by the adsorption system, avoiding back plating and wafer breakage issues caused by a mismatch between the actual adsorption force provided and the required adsorption force, thereby improving wafer yield and reducing wafer breakage.
[0081] The present application provides a wafer manufacturing system, which includes a wafer warpage monitoring device. The wafer warpage monitoring device can be positioned at a suitable location within the wafer manufacturing system as required. For example, the laser emitting device 1000 of the wafer warpage monitoring device can be positioned above or below the target wafer 100 as required. Persons skilled in the art can configure the device based on actual needs, and this is not limited herein.
[0082] like Figure 3 and Figure 4As shown, taking the arrangement above the target wafer 100 as an example, in one embodiment, the laser emitting device 1000 can be arranged on the gas spray device 200, and a laser detection device 2000 is arranged on the upper portion of the laser emitting device 1000. The laser light generated by the laser emitting device 1000 can be projected in two different directions, namely, a forward laser light 1000a and a reverse laser light 1000b. The forward laser light 1000a is reflected by the surface of the target wafer 100 to form a forward reflected laser light 1000c. The forward reflected laser light 1000c can interfere with the reverse laser light 1000b and reach the laser detection device 2000. The laser detection device 2000 records the intensity of the laser light after interference, i.e., the aforementioned light intensity data.
[0083] The laser emitting device 1000 can be located above the gas spray device 200. At this time, the forward laser light 1000a can be projected onto the target wafer 100 through the gas flow hole 210 of the gas spray device 200. The forward laser light 1000a is then reflected to form a forward reflected laser light 1000c, which is still projected back to the laser detection device 2000 through the gas flow hole 210 of the gas spray device 200.
[0084] Continue reading Figure 5 and Figure 6 As shown, the above-mentioned wafer warpage monitoring devices can be configured in multiple numbers, and the multiple wafer warpage monitoring devices can be radially distributed, thereby realizing simultaneous monitoring of the wafer warpage degree at different radial positions of the target wafer 100. Alternatively, as Figure 7 As shown, several wafer warpage monitoring devices may also be distributed in a circumferential manner, thereby simultaneously monitoring the degree of wafer warpage at different circumferential positions on the target wafer 100. In addition, the wafer warpage monitoring device may also be set on a track, thereby adjusting the position of the wafer warpage monitoring device through the track to achieve monitoring of deformation warpage at different positions of the target wafer 100. Similarly, the wafer warpage monitoring device may also be set on a rotatable tray. Those skilled in the art may set it according to actual needs, which is not limited here.
[0085] Taking the installation below the target wafer 100 as an example, in one embodiment, the above-described monitoring method can be implemented on the back of the target wafer 100. In this case, the target wafer 100 is placed on the wafer carrier 300 via a support 310. Therefore, a hole can be opened in the support 310 to facilitate the passage of the forward laser light 1000a and the forward reflected laser light 1000c. In addition, the wafer warpage monitoring device can also be installed in other locations, such as the periphery of the deposition chamber. In this case, several reflectors can be added to cause the forward reflected laser light 1000c to interfere with the reverse laser light 1000b before reaching the laser detection device 2000.
[0086] The present application provides a wafer warpage monitoring method, which includes the following steps:
[0087] Emit a forward laser light 1000a and a reverse laser light 1000b; project the forward laser light 1000a onto the surface of the target wafer 100, which is reflected by the surface of the target wafer 100 to form a forward reflected laser light 1000c, and control the forward reflected laser light 1000c and the reverse laser light 1000b to interfere with each other; obtain light intensity data after the interference of the reverse laser light 1000b and the forward reflected laser light 1000c, and calculate the wafer warpage data of the target wafer 100 based on the light intensity data.
[0088] In one embodiment, the wafer warpage data is calculated based on the following formula:
[0089]
[0090] Wherein, d is the wafer warpage data, λ is the wavelength data of the reverse laser light 1000b and the forward reflected laser light 1000c, and N is the light intensity data, which includes the number of light and dark changes of the interference fringes of the reverse laser light 1000b and the forward reflected laser light 1000c.
[0091] In the above formula, the wavelength data can be measured based on different types of lasers. Those skilled in the art can select an appropriate laser based on actual needs to determine the wavelength data of the corresponding laser. The intensity data can be determined as the number of bright and dark changes in the interference fringes between the reverse laser light 1000b and the forward reflected laser light 1000c.
[0092] Regarding the number of light and dark changes of the interference fringes, in one embodiment, the light intensity data obtained by the laser detection device 2000 may include a plurality of intensity values, wherein the plurality of intensity values may include a plurality of maximum intensity values and a plurality of minimum intensity values, see Figure 8 As shown, the maximum intensity value corresponds to the bright stripe, and the minimum intensity value corresponds to the dark stripe.
[0093] At this time, the sum of the number of all maximum intensity values and the number of all minimum intensity values is set to N. The difference between the N value of the target wafer 100 after deformation and the N value of the target wafer 100 before deformation can be determined as the number of light and dark changes of the interference fringes, and is substituted into the above formula to calculate the wafer warpage data d.
[0094] For the same point on the target wafer 100, the degree of wafer warpage at different times can be monitored and compared before and after. If a change occurs, it can be considered that the target wafer 100 has deformed or warped. For example, at different times, light intensity data of the interfering laser light can be obtained at least twice for the same point on the target wafer surface, and wafer warpage data for the same point at different times can be obtained. By comparing the different times, it can be determined whether the target wafer 100 has deformed or warped.
[0095] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0096] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.
Claims
1. A wafer warpage monitoring device, characterized in that: The wafer warpage monitoring device comprises: A laser emitting device, the laser emitting device being configured to emit a forward laser beam and a reverse laser beam, wherein the forward laser beam is configured to be projected toward a surface of a target wafer and reflected by the surface of the target wafer to form a forward reflected laser beam, wherein the reverse laser beam and the forward reflected laser beam interfere with each other to form an interference laser beam; A laser detection device is used to receive the interfering laser light and obtain light intensity data of the interfering laser light, and the light intensity data is used to calculate wafer warpage data of a target wafer.
2. The wafer warpage monitoring device according to claim 1, wherein: The wafer warpage data is calculated based on the following formula: Wherein, d is the wafer warpage data, λ is the wavelength data of the interference laser light, and N is the light intensity data; and / or, The forward laser light is projected vertically toward the surface of the target wafer.
3. The wafer warpage monitoring device according to claim 2, wherein: The light intensity data includes the number of times the interference fringes of the interfering laser light change between light and dark.
4. The wafer warpage monitoring device according to claim 3, wherein: The light intensity data includes a plurality of intensity values, wherein the plurality of intensity values include a plurality of maximum intensity values and a plurality of minimum intensity values, and the sum of the number of the maximum intensity values and the number of the minimum intensity values is N; The N value after the target wafer is deformed is set to N1, and the N value before the target wafer is deformed is set to N2. The difference between N1 and N2 is the number of light and dark changes of the interference fringes.
5. The wafer warpage monitoring device according to claim 1, wherein: The laser emitting device comprises: A device body, wherein the device body has a main body cavity therein, and the device body is provided with a forward emission window and a reverse emission window communicating with the main body cavity; an excitation source, the excitation source being disposed in the main body chamber and being used to generate a laser light source; An optical medium, wherein the optical medium is disposed in the main body chamber, and the laser light source is formed through the optical medium to emit the forward laser light and the reverse laser light in different directions; An optical reflection component is arranged in the main body cavity, the forward laser light is projected from the forward emission window through the optical reflection component, the reverse laser light is projected from the reverse emission window through the optical reflection component, and the forward reflected laser light is projected from the reverse emission window through the forward emission window and the optical reflection component.
6. The wafer warpage monitoring device according to claim 5, wherein: The optical reflective component comprises: a first reflecting element, wherein the first reflecting element is disposed in the main body chamber, and the forward laser light is projected from the forward emission window through the first reflecting element; a second reflecting element, the second reflecting element being disposed in the main body chamber, and the reverse laser light being projected from the reverse emission window via the second reflecting element; The forward reflected laser light is projected out from the backward emitting window through the forward emitting window, the second reflecting element and the first reflecting element.
7. The wafer warpage monitoring device according to claim 5, wherein: The optical reflective component comprises: a third reflecting element, the third reflecting element being disposed in the main body chamber, and the forward laser light being projected from the forward emission window via the third reflecting element; a fourth reflecting element, the fourth reflecting element being disposed in the main body chamber, and the reverse laser light being projected from the reverse emission window via the fourth reflecting element; A fifth reflecting element is provided in the main body chamber, and the forward reflected laser light is projected from the reverse emitting window through the forward emitting window, the fourth reflecting element and the fifth reflecting element.
8. A wafer manufacturing system, characterized in that: The wafer manufacturing system includes: Wafer carrier; A support member, the support member being disposed on the wafer carrying device, the support member being configured to carry a target wafer, wherein the support member has an opening for passing a forward laser beam and a forward reflected laser beam; A gas spray device, the gas spray device is arranged opposite to the wafer carrying device, The wafer warpage monitoring device according to any one of claims 1 to 7, wherein the wafer warpage monitoring device is arranged in the gas spray device.
9. A wafer warpage monitoring method, characterized in that: The wafer warpage monitoring method comprises the following steps: Emitting forward laser light and reverse laser light; Projecting the forward laser light onto the surface of the target wafer to reflect the forward laser light from the surface of the target wafer, and controlling the forward reflected laser light and the reverse laser light to interfere with each other to form an interference laser light; Light intensity data of the interfering laser light is acquired, and wafer warpage data of the target wafer is calculated based on the light intensity data.
10. The wafer warpage monitoring method according to claim 9, wherein: The wafer warpage data is calculated based on the following formula: Wherein, d is the wafer warpage data, λ is the wavelength data of the interference laser light, N is the light intensity data, and the light intensity data includes the number of light and dark changes of the interference fringes of the reverse laser light and the forward reflected laser light; and / or, At different times, light intensity data of the interfering laser light is acquired at least twice for the same point on the surface of the target wafer, and wafer warpage data at different times for the same point is acquired.