Wafer backside inspection method, inspection apparatus and application thereof

Abstract

The application provides a wafer back surface detection method, a detection device and application thereof, wherein the detection device comprises a wafer back surface detection device, an edge area chuck and a center area chuck; the wafer back surface detection device is arranged below the wafer back surface and parallel to the wafer; the edge area chuck is used for adsorbing the edge area of the wafer back surface and exposing the center area of the wafer back surface; the center area chuck is used for adsorbing the center area of the wafer back surface, and the horizontal section of the center area chuck is not larger than the center area of the wafer back surface. The wafer back surface detection method adsorbs the edge area and the center area of the wafer back surface through the edge area chuck and the center area chuck respectively, and detects the topography of the edge area and the center area of the wafer back surface through the wafer back surface detection device. The specific topography of the wafer back surface can be obtained, the position and size of impurities on the wafer back surface can be accurately judged, the production cost is reduced, the production efficiency is improved, the human resources are saved and the product quality is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of semiconductor integrated circuits, and relates to a wafer back surface detection method, a detection device and application thereof. BACKGROUND

[0002] In the field of semiconductor integrated circuits, the circuit pattern in the semiconductor integrated circuit is usually obtained by using a photolithography process. The photolithography process has been considered as the most critical step in the manufacture of integrated circuits, and needs to be used multiple times in the whole process, which has an important influence on the quality of products.

[0003] The photolithography process is a complex process, mainly including the following steps: first, forming a to-be-etched thin film layer on a substrate; then, using a glue coating machine to coat a photoresist on the to-be-etched thin film layer, and using an exposure machine to expose the photoresist by irradiating light through a mask plate with a certain pattern; then, developing the photoresist by using a developing solution, so as to transfer the pattern in the mask plate to the photoresist to form a photoresist pattern; finally, etching the to-be-etched thin film layer under the protection of the photoresist pattern, so as to transfer the photoresist pattern to the to-be-etched thin film layer, and obtain a circuit pattern by patterning the thin film layer. The photolithography process has a high requirement for the flatness of the back surface of the wafer. If the flatness of the back surface of the wafer is too poor, the vacuum adsorption effect of the exposure platform on the wafer will be poor, causing the wafer to be removed. Even if the wafer is not removed, the unevenness of the back surface of the wafer will cause the out-of-focus of the exposure pattern in the uneven area, resulting in distortion of the exposure pattern. In the prior art, there is no special check for the flatness of the back surface of the wafer before the wafer is exposed, and the result can only be known when the wafer is exposed. The wafer that is removed or the wafer with the out-of-focus exposure pattern needs to be reworked, which causes waste of machine time and materials, and prolongs the delivery time of the wafer.

[0004] Therefore, the impurities on the back surface of the wafer can cause the following problems: 1) reducing the flatness of the wafer; 2) wafer removal and rework; 3) increasing production cost; 4) reducing production efficiency; and 5) wasting human resources. It is necessary to provide a wafer back surface detection method, a detection device and application thereof, to timely warn the wafer with problems on the back surface, and notify the operator to take corresponding measures in advance, so as to avoid the wafer with impurities on the back surface from entering the subsequent process to cause the above problems. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a wafer back surface detection method, a detection device and application thereof, for detecting impurities on the back surface of the wafer, so as to avoid the wafer with impurities on the back surface from entering the subsequent process.

[0006] To achieve the above object and other related objects, the present application provides a method for detecting the back surface of a wafer, comprising the following steps:

[0007] A wafer and a detection device are provided, wherein the wafer comprises a center area of the back surface of the wafer and an edge area of the back surface of the wafer surrounding the center area of the back surface of the wafer, the detection device comprises a back surface detection device, an edge area chuck and a center area chuck, the back surface detection device is arranged below the back surface of the wafer and parallel to the wafer, the edge area chuck is used to adsorb the edge area of the back surface of the wafer and expose the center area of the back surface of the wafer, and the center area chuck is used to adsorb the center area of the back surface of the wafer, and the horizontal cross section of the center area chuck is not larger than the center area of the back surface of the wafer.

[0008] The topography of the back surface of the wafer is detected by the detection device, comprising the following steps: the edge area of the back surface of the wafer is adsorbed by the edge area chuck, and the topography of the center area of the back surface of the wafer is detected by the back surface detection device; and the center area of the back surface of the wafer is adsorbed by the center area chuck, and the topography of the edge area of the back surface of the wafer is detected by the back surface detection device.

[0009] Optionally, the step of detecting the topography of the edge area of the back surface of the wafer is before or after the step of detecting the topography of the center area of the back surface of the wafer.

[0010] Optionally, the edge area chuck comprises one of a fixed type and a movable type, and the center area chuck comprises one of a fixed type and a movable type.

[0011] Optionally, the edge area chuck comprises N top parts of "hook type" legs connected to each other, wherein N is a natural number greater than or equal to 2, the N "hook type" legs comprise a contact part in contact with the edge area of the back surface of the wafer, and the contact parts are located in the same horizontal plane.

[0012] Optionally, the longitudinal cross section of the "hook type" leg comprises one or a combination of "L" shape, "V" shape and "U" shape.

[0013] Optionally, the operation mode of the edge area chuck comprises one or a combination of a rotating type and a translating type.

[0014] Optionally, the operation mode of the center area chuck comprises one or a combination of a rotating type and a translating type.

[0015] The present application also provides a method for coating photoresist, comprising the following steps:

[0016] A wafer is provided, and photoresist is coated on the front surface of the wafer.

[0017] Detecting a topography of a wafer back surface by using any of the above methods;

[0018] Removing impurities from the wafer back surface according to the detected topography of the wafer back surface.

[0019] Optionally, after removing the impurities from the wafer back surface, the method further comprises the step of detecting the topography of the wafer back surface.

[0020] The present application also provides a detection device for detecting a topography of a wafer back surface, the wafer comprising a wafer back surface central region and a wafer back surface edge region surrounding the wafer back surface central region, the detection device comprising:

[0021] A wafer back surface detection device arranged below the wafer back surface and parallel to the wafer;

[0022] An edge region chuck for chucking the wafer back surface edge region and exposing the wafer back surface central region;

[0023] A central region chuck for chucking the wafer back surface central region, and a horizontal cross section of the central region chuck is not larger than the wafer back surface central region.

[0024] Optionally, the wafer back surface detection device comprises:

[0025] A laser for providing a light beam;

[0026] A spatial filter for filtering the light beam;

[0027] A beam expander for expanding a range of the light beam filtered by the spatial filter;

[0028] A polarizer for converting the light beam expanded by the beam expander into linearly polarized light;

[0029] A beam splitter for converting the linearly polarized light into a reflected light beam, the reflected light beam being incident on the wafer back surface through an objective lens and being converted into a transmitted light beam by the objective lens and returned to the beam splitter and converted into a transmitted light beam after being reflected by the wafer back surface;

[0030] A shear generator for generating a transverse shear amount of the transmitted light beam;

[0031] A λ / 4 wave plate for generating a constant phase difference of the transmitted light beam with the transverse shear amount;

[0032] An analyzer for converting the transmitted light beam into an interference light beam with consistent vibration direction;

[0033] An imaging objective lens for forming a polarized interference image of the interference light beam with the constant phase difference;

[0034] a photodetector, which converts the polarized interference image into an electrical signal.

[0035] Optionally, the stability of the wavelength of the light beam provided by the laser is less than or equal to 10 -3 nm.

[0036] Optionally, the light intensity error of the photodetector is less than 2%.

[0037] Optionally, the wafer back surface detection device further comprises a piezoelectric ceramic for adjusting the angle of the polarizer.

[0038] As described above, the wafer back surface detection method, detection device and application thereof have the following beneficial effects: the wafer back surface detection device and the edge region chuck and the center region chuck are used to accurately detect the wafer back surface, obtain the specific topography of the wafer back surface, and accurately determine the position and size of the impurities on the wafer back surface, thereby facilitating: 1) accurately processing the impurities on the wafer back surface, improving the cleanliness and flatness of the wafer back surface; 2) timely feedback of the information of the wafer back surface, improving the judgment of engineers; 3) rapid determination of the area where defects / doffing occurs in the exposure process, facilitating the identification of the source of the problem. Therefore, the production cost can be reduced, the production efficiency can be improved, the human resources can be saved, and the product quality can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 A flowchart of the wafer back surface detection method in the present application is shown.

[0040] Figure 2 A structure diagram of detecting the topography of the center region of the wafer back surface in the present application is shown.

[0041] Figure 3 A structure diagram of another edge region chuck adsorbing the edge region of the wafer back surface in the present application is shown.

[0042] Figure 4 A structure diagram of the edge region chuck and the center region chuck transferring the wafer in the present application is shown.

[0043] Figure 5 A structure diagram of detecting the topography of the edge region of the wafer back surface in the present application is shown.

[0044] Figure 6 A flowchart of the method of coating photoresist in the present application is shown.

[0045] Figure 7 A working structure diagram of the detection device detecting the center region of the wafer back surface in the present application is shown.

[0046] ELEMENT NUMBER EXPLANATION

[0047] 100 wafer

[0048] 110 impurities

[0049] 201 laser

[0050] 202 spatial filter

[0051] 203 beam expander

[0052] 204 polarizer

[0053] 205 beam splitter

[0054] 206 objective lens

[0055] 207 shear generator

[0056] 208 λ / 4 wave plate

[0057] 209 analyzer

[0058] 210 imaging objective

[0059] 211 photodetector

[0060] 300 beam delivery line

[0061] 400 edge zone chuck

[0062] 500 center zone chuck

[0063] 401, 501 rotation mode of operation

[0064] 402, 502 translation mode of operation DETAILED DESCRIPTION

[0065] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting, since the scope of the present application will be limited only by the appended claims.

[0066] Reference will now be made to the drawings, wherein: Figures 1-7 It is to be understood that the above-referenced arrangements are merely illustrative of the application and no limitation as to the scope of the application is intended to be implied. It will be apparent to those skilled in the art that various modifications can be made to the application without affecting the application as described. Thus, the present application is not intended to be limited to the

[0067] As Figure 1As shown, the present application provides a wafer back surface detection method, comprising the following steps:

[0068] A wafer and a detection device are provided; wherein the wafer comprises a wafer back surface center region and a wafer back surface edge region surrounding the wafer back surface center region, the detection device comprises a wafer back surface detection device, an edge region chuck and a center region chuck; the wafer back surface detection device is arranged below the wafer back surface and parallel to the wafer; the edge region chuck is used to adsorb the wafer back surface edge region and expose the wafer back surface center region; the center region chuck is used to adsorb the wafer back surface center region, and the horizontal cross section of the center region chuck is not larger than the wafer back surface center region.

[0069] The topography of the wafer back surface is detected by the detection device; comprising: adsorbing the wafer back surface edge region by the edge region chuck, and detecting the topography of the wafer center region by the wafer back surface detection device; and adsorbing the wafer back surface center region by the center region chuck, and detecting the topography of the wafer back surface edge region by the wafer back surface detection device.

[0070] In the present application, the wafer back surface edge region is adsorbed by the edge region chuck, and then the topography of the exposed wafer center region is detected by the wafer back surface detection device; the wafer back surface center region is adsorbed by the center region chuck, and then the topography of the exposed wafer edge region is detected by the wafer back surface detection device, so that the topography of the whole wafer back surface is detected in steps, and the front surface and side surface of the wafer are not damaged.

[0071] As a further embodiment of this embodiment, the detection of the topography of the wafer back surface edge region is before or after the detection of the topography of the wafer back surface center region.

[0072] Specifically, in the semiconductor process, the wafer needs to be adsorbed by the workbench most of the time, and the wafer usually has a region protruding from the workbench, so in the present application, it is preferred to first adsorb the wafer back surface edge region protruding from the workbench directly by the edge region chuck, detect the topography of the wafer back surface center region, and then adsorb the wafer back surface center region of the wafer which has been detected by the center region chuck, so as to expose the wafer edge region and detect the topography of the wafer edge region, thereby obtaining the whole topography of the wafer back surface in two steps, and reducing the risk of wafer fragmentation.

[0073] As a further embodiment of the embodiment, the edge area chuck comprises one of a fixed type and a movable type, and the operation mode of the edge area chuck comprises one or a combination of a rotating type and a translating type; the center area chuck comprises one of a fixed type and a movable type, and the operation mode of the edge area chuck comprises one or a combination of a rotating type and a translating type. The adsorption mode of the edge area chuck and the center area chuck comprises one of vacuum adsorption and electrostatic adsorption.

[0074] Specifically, as shown in Figure 2 and Figure 5 , a wafer 100 and a detection device are provided. The detection device comprises a wafer backside detection apparatus with an objective lens 206, and the objective lens 206 is beneficial to focus a light beam on the backside of the wafer 100. The backside of the wafer 100 contains impurities 110. An edge area chuck 400 adsorbs the wafer backside edge area of the wafer 100, a center area chuck 500 adsorbs the wafer backside center area, and the horizontal cross section of the center area chuck 500 is not greater than the wafer backside center area. The ranges of the wafer backside edge area and the wafer backside center area are not limited here. When the edge area chuck 400 and the center area chuck 500 are of a fixed type, the wafer backside detection apparatus needs to be of a movable type, so that there is a displacement between the wafer 100 and the wafer backside detection apparatus to obtain the topography of the backside of the wafer 100. When the edge area chuck 400 and the center area chuck 500 are of a movable type, the moving mode thereof can comprise one or a combination of a rotating type and a translating type, as shown in Figure 2 and Figure 5 , which illustrates the rotating operation mode 401, 501 and the translating operation mode 402, 502 of the edge area chuck 400 and the center area chuck 500. The speed of the rotating operation is related to the processing capacity of the wafer backside detection apparatus; the motion distance of the translating operation is set according to the ranges of the wafer backside edge area and the wafer backside center area, which are not limited here. In this embodiment, it is preferred that the edge area chuck 400 and the center area chuck 500 are both of a movable type, so as to avoid the movement of the wafer backside detection apparatus which has a higher requirement for precision, and the operation mode of the edge area chuck 400 and the center area chuck 500 is of a rotating type and a translating type which are performed synchronously, so as to improve the detection efficiency. The adsorption mode of the edge area chuck 400 and the center area chuck 500 comprises one of vacuum adsorption and electrostatic adsorption, which can be selected according to specific needs, which are not limited here.

[0075] As a further embodiment of the embodiment, the edge area chuck 400 and the center area chuck 500 can also move up and down in the vertical direction to avoid the movement of the wafer backside detecting device which requires high precision when adjusting the focal length.

[0076] As a further embodiment of the embodiment, the edge area chuck 400 comprises N top interconnected "hook type" legs, wherein N is a natural number greater than or equal to 2; the N "hook type" legs comprise contact portions in contact with the wafer backside edge area, and the contact portions are located in the same horizontal plane. The longitudinal section profile of the "hook type" leg comprises one or a combination of "L" shape, "V" shape and "U" shape.

[0077] Specifically, as shown in Figure 2 and Figure 3 , the edge area chuck 400 with different profiles is illustrated, the contact portions of the "hook type" legs have a horizontal plane, which is in contact with the wafer backside edge area of the wafer 100 to support and adsorb the wafer 100. The number, profile and distribution of the "hook type" legs are not limited here, and preferably, three circumferentially uniformly distributed "hook type" legs are combined to improve the stability of the "hook type" legs adsorbing the wafer 100. The projection of the figure surrounded by the inner edges of the N "hook type" legs on the horizontal plane is greater than or equal to the surface of the center area chuck 500, so as to form a containing space on the inner side of the N "hook type" legs to accommodate the center area chuck 500, thereby avoiding the collision between the edge area chuck 400 and the center area chuck 500 during the transfer of the wafer 100, and the risk of causing debris, such as Figure 4 .

[0078] As shown in Figure 6 , the application also provides a method for coating photoresist, comprising the following steps:

[0079] providing a wafer, and coating photoresist on the front surface of the wafer;

[0080] detecting the profile of the wafer backside by using the above-mentioned wafer backside detecting method;

[0081] removing the impurities on the wafer backside according to the detected profile of the wafer backside.

[0082] The application applies the wafer back surface detection method to the photoresist coating process, so that the wafer back surface can be accurately detected before exposure after the photoresist coating, the specific topography of the wafer back surface is obtained, the position and size of the impurities on the wafer back surface are accurately judged, and thus the following advantages are achieved: 1) the impurities on the wafer back surface can be accurately treated, and the cleanliness and flatness of the wafer back surface are improved; 2) the information of the wafer back surface can be fed back in time, the judgment of engineers is improved, the machine table is adjusted, and the product damage range is reduced; 3) the area where the defects and defocus occur in the exposure process can be quickly judged, and the problem source can be found out. Therefore, the production cost is reduced, the production efficiency is improved, the human resources are saved, and the product quality is improved.

[0083] As a further embodiment of the embodiment, the method for removing the impurities on the wafer back surface includes one or a combination of grinding and cleaning.

[0084] Specifically, the area where the impurities on the wafer back surface are located is ground or / and cleaned in a targeted manner according to the specific topography of the wafer back surface detected by the detection equipment, so that the impurities are effectively removed, the production efficiency is improved, the wafer with higher cleanliness and flatness is obtained, and then the next process is performed by using a conventional exposure method, so that the product quality is improved, and the defocus phenomenon in the exposure process is avoided.

[0085] As a further embodiment of the embodiment, after the impurities on the wafer back surface are removed, the wafer back surface is detected by using the wafer back surface detection method, so that the flatness and cleanliness of the wafer after grinding or / and cleaning are determined. If the wafer back surface still contains the impurities after repeated detection by using the wafer back surface detection method, the step of removing the impurities on the wafer back surface is performed again, so that the flatness and cleanliness of the wafer back surface are ensured. The specific number of times of repeated detection and removal of the impurities, and the judgment standard of the flatness and cleanliness of the wafer can be set according to specific needs by those skilled in the art, and are not limited here.

[0086] As shown in Figure 7 The application further provides a detection equipment which can be applied to the wafer back surface detection method. The wafer 100 includes a wafer back surface center area and a wafer back surface edge area surrounding the wafer back surface center area. The detection equipment includes: a wafer back surface detection device which is arranged in parallel with the wafer below the wafer back surface; an edge area chuck which is used for adsorbing the wafer back surface edge area and exposing the wafer back surface center area; and a center area chuck which is used for adsorbing the wafer back surface center area, and the horizontal cross section of the center area chuck is not larger than the wafer back surface center area.

[0087] Specifically, the wafer back surface detection device comprises a laser 201, a spatial filter 202, a beam expander 203, a polarizer 204, a beam splitter 205, an objective lens 206, a shear generator 207, a λ / 4 wave plate 208, a polarizing beam splitter 209, an imaging objective 210, and a photodetector 211. The laser 201 comprises one of a gas laser, a solid-state laser, a semiconductor laser, and a dye laser, to provide a light beam; the spatial filter 202 is used to filter the light beam, which filters out the interference light of non-target wavelength in the light beam emitted by the laser 201, and retains the light of the required wavelength; the beam expander 203 expands the range of the retained light beam; the polarizer 204 converts the light beam expanded by the beam expander 203 into linearly polarized light; the beam splitter 205 converts the linearly polarized light into a reflected light beam, which is incident on the wafer back surface through the objective lens 206, and after being reflected by the wafer back surface, makes the reflected light beam carry information representing the topography of the wafer back surface, and returns to the beam splitter 205 through the objective lens 206 and is converted into a transmitted light beam; the shear generator 207 generates a transverse shear amount for the transmitted light beam, and the λ / 4 wave plate 208 generates a constant phase difference for the transmitted light beam with the transverse shear amount, and forms a polarized interference light through the polarizing beam splitter 209, the angle of which can be adjusted by a piezoelectric ceramic device; the imaging objective 210 is used to form a polarized interference image; and the photodetector 211 converts the polarized interference image into an electrical signal. Figure 6 .

[0088] The wafer back surface detection device in the detection equipment, the edge area chuck, and the center area chuck adopt a common-path transverse shear interference method to meet the detection of the wafer back surface and obtain the topography of the wafer back surface. This method is non-contact with the wafer 100, avoids damage to the wafer 100, has a large phase shift interference range, is simple in device, and is easy to operate.

[0089] As a further embodiment of this embodiment, the wavelength of the light beam provided by the laser has a stability range of less than or equal to 10 -3 nm; the photodetector comprises one of a CCD and a CMOS, and the light intensity error of the photodetector is less than 2%, to improve the accuracy of the wafer back surface detection device.

[0090] In summary, the wafer back surface detection method, detection device and application thereof have the following beneficial effects: the wafer back surface detection device, the edge area chuck and the center area chuck are used to accurately detect the wafer back surface, obtain the specific topography of the wafer back surface, and accurately determine the position and size of the impurities on the wafer back surface, thereby being beneficial to: 1) accurately processing the impurities on the wafer back surface, improving the cleanliness and flatness of the wafer back surface; 2) timely feeding back the information of the wafer back surface, improving the judgment of engineers; 3) quickly determining the area where defects and defocus occur in the exposure process, and facilitating finding the source of the problem. Therefore, the production cost can be reduced, the production efficiency can be improved, the human resources can be saved, and the product quality can be improved. Therefore, the present application effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0091] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method for detecting a wafer backside, comprising the steps of: providing a wafer and a detection device, wherein the wafer comprises a wafer backside center region and a wafer backside edge region surrounding the wafer backside center region, the detection device comprises a wafer backside detection device, an edge region chuck and a center region chuck, the wafer backside detection device is arranged parallel to the wafer below the wafer backside, the edge region chuck is used to adsorb the wafer backside edge region and expose the wafer backside center region, and the center region chuck is used to adsorb the wafer backside center region, and a horizontal cross section of the center region chuck is not larger than the wafer backside center region; and detecting a topography of the wafer backside by the detection device, comprising the steps of: adsorbing the wafer backside edge region by the edge region chuck and detecting a topography of the wafer backside center region by the wafer backside detection device; and adsorbing the wafer backside center region by the center region chuck and detecting a topography of the wafer backside edge region by the wafer backside detection device. 2.The method for detecting a wafer backside according to claim 1, wherein: the step of detecting the topography of the wafer backside edge region is before or after the step of detecting the topography of the wafer backside center region. 3.The method for detecting a wafer backside according to claim 1, wherein: the edge region chuck comprises one of a fixed type and a movable type, and the center region chuck comprises one of a fixed type and a movable type. 4.The method for detecting a wafer backside according to claim 1, wherein: the edge region chuck comprises N top "hook type” legs connected to each other, wherein N is a natural number greater than or equal to 2, the N “hook type” legs comprise a contact portion in contact with the wafer backside edge region, and the contact portions are located in the same horizontal plane. 5.The method for detecting a wafer backside according to claim 4, wherein: a longitudinal cross section of the “hook type” leg comprises one or a combination of an “L” shape, a “V” shape and a “U” shape. 6.The method for detecting a wafer backside according to claim 1, wherein: a running mode of the edge region chuck comprises one or a combination of a rotating type and a translating type. 7.The method for detecting a wafer backside according to claim 1, wherein: a running mode of the center region chuck comprises one or a combination of a rotating type and a translating type. 8.A method for coating a photoresist, comprising the steps of: providing a wafer, and coating a photoresist on a front side of the wafer; detecting a topography of a wafer backside by any one of the methods for detecting a wafer backside according to claims 1-7; and removing impurities on the wafer backside according to the detected topography of the wafer backside. 9.The method for coating a photoresist according to claim 8, wherein: after removing the impurities on the wafer backside, the method further comprises the step of detecting a topography of the wafer backside. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10. A detecting device for detecting the topography of a wafer backside, the wafer comprising a wafer backside center region and a wafer backside edge region surrounding the wafer backside center region, the detecting device comprising: a wafer backside detecting device disposed below the wafer backside in parallel with the wafer; an edge region chuck for chucking the wafer backside edge region and exposing the wafer backside center region; and a center region chuck for chucking the wafer backside center region, wherein the center region chuck has a horizontal cross section no larger than the wafer backside center region.

11. The detecting device for detecting the topography of a wafer backside according to claim 10, wherein the wafer backside detecting device comprises: a laser for providing a light beam; a spatial filter for filtering the light beam; a beam expander for expanding the range of the light beam filtered by the spatial filter; a polarizer for converting the light beam expanded by the beam expander into linearly polarized light; a beam splitter for converting the linearly polarized light into a reflected light beam, the reflected light beam being incident on a wafer backside through an objective lens and being returned to the beam splitter through the objective lens after being reflected by the wafer backside and being converted into a transmitted light beam; a shear generator for generating a transverse shear amount to the transmitted light beam; a λ / 4 wave plate for generating a constant phase difference to the transmitted light beam with the transverse shear amount; an analyzer for converting the transmitted light beam into an interference light beam with consistent vibration direction; an imaging objective lens for forming a polarized interference image from the interference light beam with the constant phase difference; and a photodetector for converting the polarized interference image into an electrical signal.

12. The detecting device for detecting the topography of a wafer backside according to claim 11, wherein the wafer backside detecting device further comprises a piezoelectric ceramic for adjusting the angle of the analyzer.

13. The detecting device for detecting the topography of a wafer backside according to claim 11, wherein the wafer backside detecting device further comprises a piezoelectric ceramic for adjusting the angle of the analyzer.

14. The detecting device for detecting the topography of a wafer backside according to claim 11, wherein the wafer backside detecting device further comprises a piezoelectric ceramic for adjusting the angle of the analyzer.

15. The detecting device for detecting the topography of a wafer backside according to claim 10, wherein the chucking method of the edge region chuck and the center region chuck comprises one of vacuum chucking and electrostatic chucking, and the edge region chuck and the center region chuck are vertically movable. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The laser provides a stability of the wavelength of the light beam in the range of less than or equal to 10 -3 nm. ​ ​ ​ ​ ​ ​

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