Wafer inspection apparatus and method

Abstract

The application provides a wafer detection device. In the wafer detection device, a signal emitting unit is located on the side of the first surface of the wafer, and emits a detection light beam to the edge area of the wafer; a first signal receiving unit is located on the side of the second surface of the wafer, receives a transmission light beam generated by the detection light beam transmitting through the wafer and the protective layer, and outputs a transmission signal; a second signal receiving unit is located on the side of the first surface of the wafer, receives a reflection light beam generated by the detection light beam reflecting through the wafer and the protective layer, and outputs a reflection signal; a data processing unit fits the received transmission signal and the reflection signal to form a composite signal; a feedback control unit determines the position information of the wafer cutout according to the composite signal, and makes the cutout stay at a preset position, so that the pre-alignment of the wafer is realized. The wafer detection device can meet the pre-alignment requirement of the wafer with a transparent or semi-transparent protective layer pasted on the surface. The application also provides a wafer detection method.

Description

TECHNICAL FIELD

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

[0002] In the manufacturing process of a wafer, a quantity detection machine and some process machines need to find the notch of the wafer edge through a pre-aligner before production starts, so as to pre-align the wafer, ensure that the detection area can be accurately found during detection, and ensure that the process machine can realize the deposition process or ion implantation process by determining the notch position during production. If the notch of the wafer cannot be confirmed or is confirmed incorrectly, the detection accuracy and product electrical performance will be directly affected.

[0003] The traditional method for finding the notch of the wafer is to install a laser emitter and a laser receiver above and below the wafer respectively, and to receive feedback signals on one side of the wafer through the laser receiver, and to determine the notch position of the wafer through the feedback signals. However, with the development of semiconductor products and processes, in the manufacturing process of semiconductor devices, some products, such as insulated gate bipolar transistors (IGBT), need to be pasted with a glass plate on the front surface of the wafer after the front surface is processed, and the glass plate usually covers the front surface of the wafer and the notch at the edge of the wafer, and then the back surface of the wafer is processed.

[0004] In the process after the glass plate is pasted on the front surface of the wafer, when the traditional method for finding the notch of the wafer is used to find the notch of the wafer, the intensity of the received feedback signals is severely reduced due to the influence of the glass plate, and the notch of the wafer cannot be determined or the positioning accuracy of the notch is low according to the feedback signals, which causes the wafer to be offset in the sliding or placement position in the workbench, affects the detection accuracy of the wafer and the production yield of the product. In addition, the traditional method for finding the notch of the wafer cannot detect the notch defect of the wafer edge. SUMMARY

[0005] The present application provides a wafer detection device and a wafer detection method, which can meet the pre-alignment requirements and / or notch defect detection requirements of wafers pasted with transparent or semi-transparent protective layers such as glass plates on the surface, and have high pre-alignment accuracy and defect detection accuracy, which is beneficial to improve the problem of wafer being offset in the sliding or placement position in the workbench, improve the detection accuracy of the wafer and the production yield of the product.

[0006] In order to achieve the above object, the present application provides a wafer detection device. The wafer detection device is used for pre-alignment of a wafer with a protective layer formed on a surface of the wafer, an edge region of the wafer has a notch, the protective layer extends from the surface of the wafer to cover an area where the notch is located, and the protective layer is transparent or semi-transparent material. The wafer detection device comprises:

[0007] a signal emitting unit located on a first surface side of the wafer, used for emitting a detection light beam to the edge region of the wafer;

[0008] a first signal receiving unit located on a second surface side of the wafer, the second surface is opposite to the first surface in direction, the first signal receiving unit is used for receiving a transmission light beam generated by detecting the detection light beam transmitting through the wafer and the protective layer, and outputting a transmission signal;

[0009] a second signal receiving unit located on the first surface side of the wafer, used for receiving a reflection light beam generated by detecting the detection light beam reflecting through the wafer and the protective layer, and outputting a reflection signal;

[0010] a data processing unit, used for receiving the transmission signal and the reflection signal, fitting the transmission signal and the reflection signal to form a composite signal; and

[0011] a feedback control unit, used for determining position information of the notch according to the composite signal, and making the notch stay at a preset position to realize pre-alignment of the wafer.

[0012] Optionally, the data processing unit fitting the transmission signal and the reflection signal to form a composite signal comprises: calculating an absolute value of a difference between an instantaneous intensity value of the transmission signal and a transmission signal intensity reference value to obtain a first difference value, calculating an absolute value of a difference between an instantaneous intensity value of the reflection signal and a reflection signal intensity reference value to obtain a second difference value, and superimposing the first difference value and the second difference value at the same time point to form the composite signal.

[0013] The feedback control unit determines the position information of the notch according to peak value information of the composite signal.

[0014] Optionally, an intensity value of the transmission signal generated when the detection light beam irradiates a non-notch area of the wafer is taken as the transmission signal intensity reference value I BSL1 , an intensity value of the reflection signal generated when the detection light beam irradiates the non-notch area of the wafer is taken as the reflection signal intensity reference value I BSL2 ; for the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, the first difference value ΔI1=|I1-IBSL1 |, the second difference value ΔI2 = |I2-I BSL2 |, the instantaneous intensity value I 复合 = ΔI 1+ ΔI2.

[0015] Optionally, the wafer detection device further comprises a worktable, the worktable is used for placing the wafer; in the process of determining the notch, the worktable drives the wafer to rotate; the feedback control unit controls the rotation of the worktable according to the position information of the notch so that the notch stays at a preset position, and the pre-alignment of the wafer is realized.

[0016] The application further provides a wafer detection device. The wafer detection device is used for detecting a notch defect of a wafer with a protective layer formed on a surface of the wafer, an edge region of the wafer has a notch, the protective layer extends from the surface of the wafer to cover an area where the notch is located, and the protective layer is transparent or translucent material. The wafer detection device comprises: a signal emitting unit located on a first surface side of the wafer, used for emitting a detection light beam to the edge region of the wafer; a first signal receiving unit located on a second surface side of the wafer, the second surface is opposite to the first surface in terms of direction, the first signal receiving unit is used for receiving a transmission light beam generated by detecting the detection light beam transmitting through the wafer and the protective layer, and outputting a transmission signal; a second signal receiving unit located on the first surface side of the wafer, used for receiving a reflection light beam generated by detecting the detection light beam reflecting through the wafer and the protective layer, and outputting a reflection signal; a data processing unit, used for receiving the transmission signal and the reflection signal, fitting the transmission signal and the reflection signal to form a composite signal; and a feedback control unit, used for judging that there is a notch defect in the edge region of the wafer according to the existence of a peak value of the composite signal in which the values are not equal, and issuing an alarm.

[0017] Optionally, the data processing unit fitting the transmission signal and the reflection signal to form a composite signal comprises: for the same time point, calculating an absolute value of a difference between an instantaneous intensity value of the transmission signal and a transmission signal intensity reference value to obtain a first difference value, calculating an absolute value of a difference between an instantaneous intensity value of the reflection signal and a reflection signal intensity reference value to obtain a second difference value, and superimposing the first difference value and the second difference value at the same time point to form a composite signal.

[0018] Optionally, an intensity value of the transmission signal generated when the detection light beam irradiates a non-notch area of the wafer is taken as a transmission signal intensity reference value I BSL1 , and an intensity value of the reflection signal generated when the detection light beam irradiates the non-notch area of the wafer is taken as a reflection signal intensity reference value I BSL2; for the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, the first difference ΔI1 = |I1-I BSL1 |, the second difference ΔI2 = |I2-I BSL2 |, the instantaneous intensity value of the composite signal I 复合 = ΔI 1+ ΔI2.

[0019] Optionally, the wafer detection device further comprises a workbench, the workbench is used for placing the wafer; in the process of determining the notch defect, the workbench drives the wafer to rotate.

[0020] Optionally, the wafer detection device is applied in wafer warpage defect judgment; the data processing unit transmits the first difference and the second difference of each time point to the feedback control unit, the feedback control unit respectively evaluates the first difference and the second difference, when the first difference exceeds a first preset range and / or the second difference exceeds a second preset range, it is judged that the wafer has warpage defect and an alarm is issued.

[0021] The application further provides a wafer detection method. The wafer detection method uses the above wafer detection device to pre-align a wafer with a protective layer formed on the surface, the edge region of the wafer has a notch, the protective layer extends from the surface of the wafer to cover the region where the notch is located, and the protective layer is transparent or translucent material. The wafer detection method comprises:

[0022] Emit a detection light beam from the first surface side of the wafer to the edge region of the wafer;

[0023] Receive a transmission light beam generated by the detection light beam transmitting through the wafer and the protective layer on the second surface side of the wafer, and convert the transmission light beam into a transmission signal, the second surface is opposite to the first surface;

[0024] Receive a reflection light beam generated by the detection light beam reflecting through the wafer and the protective layer on the first surface side of the wafer, and convert the reflection light beam into a reflection signal;

[0025] Fit the transmission signal and the reflection signal to form a composite signal; and

[0026] Determine the position information of the notch according to the composite signal, and make the notch stay at a preset position, so as to realize the pre-alignment of the wafer.

[0027] Optionally, the method of fitting the transmission signal and the reflection signal to form a composite signal comprises: calculating the absolute value of the difference between the instantaneous intensity value of the transmission signal and a transmission signal intensity reference value to obtain a first difference value, calculating the absolute value of the difference between the instantaneous intensity value of the reflection signal and a reflection signal intensity reference value to obtain a second difference value, and superimposing the first difference value and the second difference value at the same time point to form a composite signal.

[0028] The method of determining the position information of the cutout according to the composite signal comprises: determining the position information of the cutout according to the peak value information of the composite signal.

[0029] Optionally, the intensity value of the transmission signal generated when the detection beam irradiates the non-cutout area of the wafer is taken as the transmission signal intensity reference value I BSL1 The intensity value of the reflection signal generated when the detection beam irradiates the non-cutout area of the wafer is taken as the reflection signal intensity reference value I BSL2 The instantaneous intensity value of the transmission signal is I1 and the instantaneous intensity value of the reflection signal is I2 at the same time point, the first difference value ΔI1 = |I1-I BSL1 |, the second difference value ΔI2 = |I2-I BSL2 |, and the instantaneous intensity value I 复合 of the composite signal is ΔI 1+ ΔI2.

[0030] The present application also provides a wafer detection method. The wafer detection method uses the wafer detection device described above to detect the notch defects of a wafer with a protective layer formed on the surface, the edge area of the wafer has a cutout, the protective layer extends from the surface of the wafer to cover the area where the cutout is located, and the protective layer is transparent or translucent material; the wafer detection method comprises:

[0031] Emit a detection beam from the first surface side of the wafer to the edge area of the wafer;

[0032] Receive a transmission beam generated by the detection beam transmitted through the wafer and the protective layer on the second surface side of the wafer, and convert the transmission beam into a transmission signal, the second surface is opposite to the first surface;

[0033] Receive a reflection beam generated by the detection beam reflected through the wafer and the protective layer on the first surface side of the wafer, and convert the reflection beam into a reflection signal;

[0034] Fit the transmission signal and the reflection signal to form a composite signal; and

[0035] When the complex signal has a peak value that is not equal to zero, it is determined that the wafer has a notch defect and an alarm is issued.

[0036] Optionally, the method of fitting the transmission signal and the reflection signal to form a complex signal comprises: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmission signal and the transmission signal intensity reference value to obtain a first difference value, calculating the absolute value of the difference between the instantaneous intensity value of the reflection signal and the reflection signal intensity reference value to obtain a second difference value, and superimposing the first difference value and the second difference value at the same time point to form a complex signal.

[0037] Optionally, the intensity value of the transmission signal generated when the detection beam is irradiated on the non-cutting area of the wafer is taken as the transmission signal intensity reference value I BSL1 , the intensity value of the reflection signal generated when the detection beam is irradiated on the non-cutting area of the wafer is taken as the reflection signal intensity reference value I BSL2 ; for the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, the first difference value ΔI1=|I1-I BSL1 |, the second difference value ΔI2=|I2-I BSL2 |, and the instantaneous intensity value I 复合 of the complex signal is ΔI 1+ ΔI2.

[0038] Optionally, the wafer detection method is applied in wafer warping defect judgment; the first difference value and the second difference value are evaluated respectively, and when the first difference value exceeds a first preset range and / or the second difference value exceeds a second preset range, it is determined that the wafer has a warping defect and an alarm is issued.

[0039] Compared with the prior art of determining the notch position of the wafer only according to the light signal received on one side of the wafer, the wafer detection device and the wafer detection method provided by the present application perform fitting on the transmission signal on one side of the wafer and the reflection signal on the other side of the wafer to form a complex signal, which is equivalent to amplifying the intensity of the transmission beam and the reflection beam, and can meet the detection requirements (including pre-alignment requirements and / or notch defect detection requirements) of the wafer with a transparent or semi-transparent protective layer pasted on the surface, has high detection precision, and is beneficial to improving the problem of wafer sliding or placement position offset in the workbench, and improving the detection accuracy of the wafer and the production yield of the product. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The figure is a schematic diagram of the wafer detection device provided by the present application.

[0041] Figure 2A signal curve diagram obtained by detecting a wafer with a notch defect by using the wafer detection device according to an embodiment of the present application.

[0042] Figure 3 A signal curve diagram obtained by detecting a wafer with a notch defect by using the wafer detection device according to an embodiment of the present application.

[0043] Figure 4 A signal curve diagram obtained by detecting a wafer with a center upward warping by using the wafer detection device according to an embodiment of the present application.

[0044] Figure 5 A signal curve diagram obtained by detecting a wafer with an edge upward warping by using the wafer detection device according to an embodiment of the present application.

[0045] Figure 6 A flowchart of a wafer detection method according to an embodiment of the present application.

[0046] Figure 7 A flowchart of a wafer detection method according to another embodiment of the present application.

[0047] Explanation of reference numerals:

[0048] 100 - wafer; 100a - notch; 101 - protective layer; 201 - signal emitting unit; 202 - first signal receiving unit; 203 - second signal receiving unit; 204 - data processing unit; 205 - feedback control unit. DETAILED DESCRIPTION

[0049] The wafer detection device and wafer detection method according to the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description. It should be noted that the accompanying drawings are very simplified and use non-precise proportions, only for the purpose of conveniently and clearly assisting the description of the embodiments of the present application.

[0050] Embodiment One

[0051] Figure 1 A schematic diagram of the wafer detection device according to the present application. As shown in the figure, the wafer detection device according to the present embodiment is used for pre-alignment of a wafer 100 with a protective layer 101 formed on the surface thereof, the edge region of the wafer 100 has a notch 100a, the protective layer 101 extends from the surface of the wafer 100 to cover the region where the notch 100a is located, and the protective layer 101 is a transparent or semi-transparent material. Figure 1 As shown in the figure, the wafer detection device according to the present embodiment is used for pre-alignment of a wafer 100 with a protective layer 101 formed on the surface thereof, the edge region of the wafer 100 has a notch 100a, the protective layer 101 extends from the surface of the wafer 100 to cover the region where the notch 100a is located, and the protective layer 101 is a transparent or semi-transparent material.

[0052] As shown in the figure, the wafer detection device according to the present embodiment is used for pre-alignment of a wafer 100 with a protective layer 101 formed on the surface thereof, the edge region of the wafer 100 has a notch 100a, the protective layer 101 extends from the surface of the wafer 100 to cover the region where the notch 100a is located, and the protective layer 101 is a transparent or semi-transparent material. Figure 1As shown, the wafer detection device comprises a signal emitting unit 201, a first signal receiving unit 202, a second signal receiving unit 203, a data processing unit 204 and a feedback control unit 205. The signal emitting unit 201 is located on the first surface side of the wafer 100, and is configured to emit a detection light beam to the edge region of the wafer 100. The first signal receiving unit 202 is located on the second surface side of the wafer 100, the second surface of the wafer 100 is opposite to the first surface, and the first signal receiving unit 202 is configured to receive a transmission light beam generated by the detection light beam transmitting through the wafer 100 and the protective layer 101, and output a transmission signal. The second signal receiving unit 203 is located on the first surface side of the wafer 100, and is configured to receive a reflection light beam generated by the detection light beam reflecting through the wafer 100 and the protective layer 101, and output a reflection signal. The data processing unit 204 is configured to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal. The feedback control unit 205 is configured to determine the position information of the cutout according to the composite signal, and make the cutout stay at a preset position, so as to realize the pre-alignment of the wafer.

[0053] Specifically, one of the first surface and the second surface of the wafer 100 is the front surface of the wafer 100, and the other is the back surface of the wafer 100. The protective layer 101 covers the first surface or the second surface of the wafer 100.

[0054] For example, referring to Figure 1 As shown, in this embodiment, the first surface of the wafer 100 is the front surface of the wafer, and the second surface of the wafer 100 is the back surface of the wafer. The protective layer 101 covers the front surface of the wafer 100 to protect the front surface of the wafer 100 in subsequent processes, for example, to protect the semiconductor devices and / or circuits that have been manufactured on the front surface of the wafer. The protective layer 101 can be a glass plate with the same size as the wafer 100, and the protective layer 101 can be attached to the front surface of the wafer 100, but is not limited thereto. In other embodiments, the protective layer 101 can be a transparent or semi-transparent material layer such as silicon carbide (SiC) or a special coating such as an anti-reflection coating. The protective layer 101 can also be connected to the wafer 100 in other ways.

[0055] For example, referring to Figure 1 As shown, the signal emitting unit 201 can be located on the front surface side of the wafer 100, and emit a detection light beam to the edge region of the wafer 100. When the detection light beam is incident on the protective layer 101 and the wafer 100, transmission and reflection will occur.

[0056] The first signal receiving unit 202 can be located on the back surface side of the wafer 100, and is configured to receive a transmission light beam generated by the detection light beam transmitting through the wafer 100 and the protective layer 101, and output a transmission signal.

[0057] The second signal receiving unit 203 is located on the front side of the wafer 100, and is configured to receive a reflected light beam generated by reflecting the detection light beam on the wafer 100 and the protective layer 101, and output a reflected signal.

[0058] In this embodiment, the first signal receiving unit 202 and the signal transmitting unit 201 are located on different sides of the wafer 100, and the signal transmitting unit 201 and the second signal receiving unit 203 are located on the same side of the wafer 100. The signal transmitting unit 201 can be a laser transmitter, and the first signal receiving unit 202 and the second signal receiving unit 203 can both be laser receivers, but are not limited thereto.

[0059] For example, referring to FIG. 2, the signal transmitting unit 201 can be a laser transmitter, and the first signal receiving unit 202 and the second signal receiving unit 203 can both be laser receivers. Figure 1 For example, referring to FIG. 2, the signal transmitting unit 201 can be a laser transmitter, and the first signal receiving unit 202 and the second signal receiving unit 203 can both be laser receivers.

[0060] For example, referring to FIG. 2, the signal transmitting unit 201 can be a laser transmitter, and the first signal receiving unit 202 and the second signal receiving unit 203 can both be laser receivers.

[0061] In this embodiment, the wafer detection device can further include a workbench (not shown) for placing the wafer 100; during the determination of the cutout 100a of the wafer, the workbench drives the wafer 100 to rotate, so that the detection light beam of the signal transmitting unit 201 can irradiate and scan the entire edge region of the wafer 100. It should be noted that one rotation of the wafer 100 can correspond to one period of the transmitted signal and one period of the reflected signal. Figure 1

[0062] For example, referring to FIG. 2, the signal transmitting unit 201 can be a laser transmitter, and the first signal receiving unit 202 and the second signal receiving unit 203 can both be laser receivers. Figure 1 ​As shown, the data processing unit 204 is connected to the first signal receiving unit 202 and the second signal receiving unit 203. The data processing unit 204 receives the transmitted signal output by the first signal receiving unit 202 and the reflected signal output by the second signal receiving unit 203, and then fits the transmitted signal and the reflected signal to form a composite signal.

[0063] Specifically, the step of the data processing unit 204 fitting the transmitted signal and the reflected signal to form a composite signal may include: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmitted signal and the reference value of the transmitted signal intensity to obtain a first difference value ΔI1, calculating the absolute value of the difference between the instantaneous intensity value of the reflected signal and the reference value of the reflected signal intensity to obtain a second difference value ΔI2, and superimposing the first difference value ΔI1 and the second difference value ΔI2 at the same time point to form a composite signal.

[0064] For example, the intensity value of the transmission signal generated when the detection beam irradiates the non-notched area of ​​the wafer 100 is used as the transmission signal intensity reference value I. BSL1 The intensity value of the reflected signal generated when the detection beam illuminates the non-notched area of ​​the wafer 100 is used as the reference value I of the reflected signal intensity. BSL2 For the same point in time, the instantaneous intensity value of the transmitted signal is I1, and the instantaneous intensity value of the reflected signal is I2. The first difference ΔI1 = |I1 - I2| BSL1 The second difference ΔI2 = |I2 - I BSL2 |, the instantaneous intensity value I of the composite signal 复合 =ΔI 1+ ΔI2.

[0065] Figure 2 This is a schematic diagram of the signal curve obtained by detecting the dicing of a wafer using a wafer inspection apparatus provided in an embodiment of the present invention. (Reference) Figure 2 As shown, the wafer is a normal wafer with a protective layer formed on its surface. A normal wafer can be defined as a wafer that is flat and has no gaps or defects in its edge areas.

[0066] Because the intensity of the transmitted beam generated by the detection beam passing through the area where the cut is located is greater than the intensity of the transmitted beam generated by the detection beam passing through the non-cut area, reference Figure 2 As shown, for the transmission signal curve, the time of the peak value corresponds to the time when the detection beam illuminates the area where the cut is located, and the time of the trough value corresponds to the time when the detection beam illuminates the non-cut area. Furthermore, the trough value of the curve can be used as the reference value I for the transmission signal intensity. BSL1 .

[0067] Because the intensity of the reflected beam generated by the detection beam in the incision area is less than the intensity of the reflected beam generated by the detection beam in the non-incision area, reference Figure 2 As shown, for the reflection signal curve, the time of the trough corresponds to the time when the detection beam illuminates the area where the cut is located, and the time of the peak corresponds to the time when the detection beam illuminates the non-cut area. Furthermore, the peak value of the curve can be used as the reference value I for the reflection signal intensity. BSL2 .

[0068] like Figure 2 As shown, within the same period, the time when the peak value of the transmitted signal appears is the same as the time when the trough value of the reflected signal appears, and the time when the peak value of the composite signal appears is the same as the time when the peak value of the transmitted signal appears and the trough value of the reflected signal appears. The wafer notch location can be determined based on the peak value information of the composite signal. It should be noted that the peak height of the composite signal formed by fitting the transmitted and reflected signals by the data processing unit is approximately the sum of the peak heights of the transmitted and reflected signals. The composite signal is equivalent to amplifying both the transmitted and reflected signals. Therefore, determining the wafer notch location through the composite signal helps improve the pre-alignment accuracy of the wafer and can meet the pre-alignment requirements of wafers with transparent or semi-transparent protective layers on their surfaces.

[0069] refer to Figure 1 As shown, the wafer inspection apparatus also includes a feedback control unit 205. The feedback control unit 205 is used to determine the position information of the notch 100a based on the composite signal and to keep the notch 100a at a preset position, thereby achieving pre-alignment of the wafer. For example, the feedback control unit 205 determines the position information of the notch 100a based on the peak value information of the composite signal, and controls the rotation of the stage based on the position information of the notch 100a to keep the notch at the preset position, thereby achieving pre-alignment of the wafer 100.

[0070] Since the wafer inspection device of this application can accurately position the wafer, the pre-alignment pass rate of the wafer is high when performing processes such as ion implantation that require consideration of wafer crystal orientation. This can effectively reduce anomalies caused by wafer pre-alignment failure or inaccuracy, and improve process yield.

[0071] In the embodiment, the wafer detection device can be applied in wafer warping defect judgment, i.e. the wafer detection device has the function of judging wafer warping. Specifically, the data processing unit 204 of the wafer detection device can transmit the first difference value ΔI1 and the second difference value ΔI2 of each time point to the feedback control unit 205, and the feedback control unit 205 respectively evaluates the first difference value ΔI1 and the second difference value ΔI2. When the first difference value ΔI1 exceeds the first preset range and / or the second difference value ΔI2 exceeds the second preset range, it is judged that the wafer has a warping defect and an alarm is issued.

[0072] Exemplarily, Figure 4 The signal curve obtained by the wafer detection device using an embodiment of the present application to detect the cut of the wafer with the center upward warping is shown. When the center of the wafer is upwardly warped, the wafer is a upside-down disc on the workbench. The reflection signal curve and the transmission signal curve obtained by detecting the cut of the wafer are as shown in Figure 4 As shown, the difference between the peak value of the transmission signal and the transmission signal intensity reference value is small, and the difference between the valley value of the reflection signal and the reflection signal intensity reference value is large.

[0073] Exemplarily, Figure 5 The signal curve obtained by the wafer detection device using an embodiment of the present application to detect the cut of the wafer with the edge upward warping is shown. When the edge of the wafer is upwardly warped, the wafer is a disc on the workbench. The reflection signal curve and the transmission signal curve obtained by detecting the cut of the wafer are as shown in Figure 5 As shown, the difference between the peak value of the transmission signal and the transmission signal intensity reference value is large, and the difference between the valley value of the reflection signal and the reflection signal intensity reference value is small.

[0074] The first difference value ΔI1 is the absolute value of the difference between the instantaneous intensity value of the transmission signal and the transmission signal intensity reference value, and the second difference value ΔI2 is the absolute value of the difference between the instantaneous intensity value of the reflection signal and the reflection signal intensity reference value, wherein, Figure 4 and Figure 5 Exemplarily, the difference ΔI1, ΔI2 between the extreme value of the transmission signal curve and the reflection signal curve and the reference value is shown. Referring to Figure 4 and Figure 5 When the wafer has warping, the first difference value ΔI1 and the second difference value ΔI2 will deviate from the normal condition, therefore, the feedback control unit 205 respectively evaluates the first difference value ΔI1 and the second difference value ΔI2. When the first difference value ΔI1 exceeds the first preset range and / or the second difference value ΔI2 exceeds the second preset range, it can be judged that the wafer has a warping defect.

[0075] The feedback control unit 205 finds the wafer has a warping defect and issues an alarm, which can prevent the warped wafer from entering the machine to cause unnecessary downtime and scrapping. In addition, by analyzing the first difference ΔI1 and the second difference ΔI2, the warping direction and the warping position of the wafer can also be determined.

[0076] It should be noted that the first preset range and the second preset range can be set according to the conditions of the first difference ΔI1 and the second difference ΔI2 corresponding to the normal wafer.

[0077] Embodiment Two

[0078] The wafer detection device provided in the embodiment is different from that in Embodiment One in that the feedback control unit is configured to determine that the edge region of the wafer has a notch defect and issue an alarm when the composite signal has a peak value that is not equal to zero. The wafer detection device of the embodiment has the same features as those of Embodiment One, which will not be repeated here.

[0079] Reference Figure 1 As shown in the figure, the wafer detection device provided in the embodiment is configured to detect a notch defect of a wafer 100 having a protective layer 101 formed on the surface thereof. The edge region of the wafer 100 has a cut 100a, and the protective layer 101 extends from the surface of the wafer 100 to cover the region where the cut 100a is located. The protective layer 101 is transparent or translucent.

[0080] The wafer detection device comprises a signal emitting unit 201, a first signal receiving unit 202, a second signal receiving unit 203, a data processing unit 204, and a feedback control unit 205.

[0081] The signal emitting unit 201 is located on the first surface side of the wafer 100 and is configured to emit a detection light beam to the edge region of the wafer 100.

[0082] The first signal receiving unit 202 is located on the second surface side of the wafer 100, and the second surface is opposite to the first surface. The first signal receiving unit 202 is configured to receive a transmission light beam generated by detecting the detection light beam that has transmitted through the wafer 100 and the protective layer 101, and output a transmission signal.

[0083] The second signal receiving unit 203 is located on the first surface side of the wafer 100 and is configured to receive a reflection light beam generated by detecting the detection light beam that has been reflected by the wafer 100 and the protective layer 101, and output a reflection signal.

[0084] The data processing unit 204 is configured to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal.

[0085] The feedback control unit 205 is used to determine that there is a notch defect in the edge region of the wafer and issue an alarm when there are high peak values ​​with unequal values ​​in the composite signal.

[0086] Specifically, the data processing unit 204 may fit the transmitted signal and the reflected signal to form a composite signal by: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmitted signal and the reference value of the transmitted signal intensity to obtain a first difference value; calculating the absolute value of the difference between the instantaneous intensity value of the reflected signal and the reference value of the reflected signal intensity to obtain a second difference value; and superimposing the first difference value and the second difference value at the same time point to form a composite signal.

[0087] For example, the intensity value of the transmission signal generated when the detection beam irradiates the non-notched area of ​​the wafer 100 is used as the transmission signal intensity reference value I. BSL1 The intensity value of the reflected signal generated when the detection beam illuminates the non-notched area of ​​the wafer 100 is used as the reference value I of the reflected signal intensity. BSL2 For the same point in time, the instantaneous intensity value of the transmitted signal is I1, and the instantaneous intensity value of the reflected signal is I2. The first difference ΔI1 = |I1 - I2| BSL1 The second difference ΔI2 = |I2 - I BSL2 |, the instantaneous intensity value I of the composite signal 复合 =ΔI 1+ ΔI2.

[0088] Figure 3 This is a schematic diagram of signal curves obtained by using a wafer inspection apparatus provided in an embodiment of the present invention to inspect a wafer with notch defects. When a notch defect exists in the edge region of the wafer, that is, when there is a notch other than a notch in the edge region of the wafer, the notch of the wafer is detected to obtain reflection signal curves, transmission signal curves, and composite signal curves as shown. Figure 3 As shown, the reflection signal curve has valleys with unequal values, and the transmission signal curve has peaks with unequal values. That is, both the reflection and transmission signal curves have impurities. As a result, the composite signal curve formed by fitting also has impurities (i.e., it has peaks with unequal values). Therefore, when the feedback control unit 205 detects that the composite signal has peaks with unequal values, the feedback control unit 205 can determine that there is a notch defect in the edge region of the wafer 100.

[0089] When the feedback control unit 205 detects a notch defect in the edge region of the wafer and issues an alarm, it prevents wafers with notch defects from entering the machine. This further improves the problem of wafer slippage or misalignment within the worktable, increasing wafer detection accuracy and / or product yield, and is real-time. Furthermore, the feedback control unit 205 can determine the location of the notch defect based on the composite signal, specifically by identifying the noise peaks in the composite signal. This improves the coordinate accuracy of the notch defect, facilitating the review tool to locate and photograph the defect for analysis and improvement planning.

[0090] In this embodiment, the wafer inspection device can be used for wafer warpage defect detection, meaning the wafer inspection device has the function of detecting wafer warpage. Specifically, the data processing unit 204 of the wafer inspection device can transmit the first difference ΔI1 and the second difference ΔI2 at various time points to the feedback control unit 205. The feedback control unit 205 evaluates the first difference ΔI1 and the second difference ΔI2 respectively. When the first difference ΔI1 exceeds a first preset range and / or the second difference ΔI2 exceeds a second preset range, it determines that the wafer has a warpage defect and issues an alarm.

[0091] Example 3

[0092] This embodiment provides a wafer inspection device. (Reference) Figure 1 As shown, the wafer inspection device is used to pre-align and detect notch defects on a wafer 100 with a protective layer 101 formed on its surface. The edge region of the wafer 100 has a notch 100a. The protective layer 101 extends from the surface of the wafer 100 to cover the area where the notch 100a is located, and the protective layer 101 is a transparent or translucent material.

[0093] The wafer inspection device includes: a signal transmitting unit 201, a first signal receiving unit 202, a second signal receiving unit 203, a data processing unit 204, and a feedback control unit 205.

[0094] The signal transmitting unit 201 is located on one side of the first surface of the wafer 100 and is used to emit a detection beam toward the edge region of the wafer 100.

[0095] The first signal receiving unit 202 is located on one side of the second surface of the wafer 100, the second surface being opposite to the orientation of the first surface. The first signal receiving unit 202 is used to receive and detect the transmitted light beam generated by the detection beam passing through the wafer 100 and the protective layer 101, and outputs a transmission signal.

[0096] The second signal receiving unit 203 is located on the first surface side of the wafer 100, and is configured to receive a reflected light beam generated by detecting the detection light beam reflected by the wafer 100 and the protective layer 101, and output a reflected signal.

[0097] The data processing unit 204 is configured to receive the transmitted signal and the reflected signal, and fit the transmitted signal and the reflected signal to form a composite signal.

[0098] The feedback control unit 205 is configured to determine the position information of the cutout 100a of the wafer according to the composite signal, and make the cutout 100a stay at a preset position, so as to realize the pre-alignment of the wafer 100. When the composite signal has a peak value that is not equal to zero, the feedback control unit 205 is configured to determine that there is a notch defect in the edge region of the wafer 100 and issue an alarm.

[0099] It should be noted that the wafer detection device provided in the embodiment has the same features as those of the wafer detection device provided in the first embodiment and the second embodiment, which will not be described here.

[0100] Embodiment Four

[0101] The wafer detection method provided in the embodiment is used for pre-aligning a wafer with a protective layer formed on a surface of the wafer by using the wafer detection device provided in the first embodiment. The edge region of the wafer has a cutout, the protective layer extends from the surface of the wafer to cover the region where the cutout is located, and the protective layer is a transparent or translucent material.

[0102] Figure 6 A flowchart of the wafer detection method provided in an embodiment of the present application is shown in FIG. 4. Figure 6 As shown in FIG. 4, the wafer detection method comprises the following steps.

[0103] S1, emitting a detection light beam from the first surface side of the wafer to the edge region of the wafer;

[0104] S2, receiving a transmitted light beam generated by detecting the detection light beam transmitted through the wafer and the protective layer on the second surface side of the wafer, and converting the transmitted light beam into a transmitted signal, the second surface being opposite to the first surface in orientation;

[0105] S3, receiving a reflected light beam generated by detecting the detection light beam reflected by the wafer and the protective layer on the first surface side of the wafer, and converting the reflected light beam into a reflected signal;

[0106] S4, fitting the transmitted signal and the reflected signal to form a composite signal; and

[0107] S5, determining the position information of the cutout according to the composite signal, and making the cutout stay at a preset position, so as to realize the pre-alignment of the wafer.

[0108] Exemplarily, the step S1 can be performed by the signal transmitting unit 201 in the above embodiment. The step S2 can be performed by the first signal receiving unit 202 in the above embodiment. The step S3 can be performed by the second signal receiving unit 203 in the above embodiment. The step S4 can be performed by the data processing unit 204 in the above embodiment. The step S5 can be performed by the feedback control unit 205 in the above embodiment.

[0109] In the embodiment, the method for fitting the transmission signal and the reflection signal to form the composite signal in the step S4 can include: obtaining a first difference value by calculating the absolute value of the difference between the instantaneous intensity value of the transmission signal and the transmission signal intensity reference value, and obtaining a second difference value by calculating the absolute value of the difference between the instantaneous intensity value of the reflection signal and the reflection signal intensity reference value, for the same time point; and superimposing the first difference value and the second difference value of the same time point to form the composite signal.

[0110] Exemplarily, the intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut region of the wafer is taken as the transmission signal intensity reference value I BSL1 The intensity value of the reflection signal generated when the detection light beam is irradiated on the non-cut region of the wafer is taken as the reflection signal intensity reference value I BSL2 ; for the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, the first difference value ΔI1 = |I1-I BSL1 |, the second difference value ΔI2 = |I2-I BSL2 |, and the instantaneous intensity value I 复合 of the composite signal is ΔI 1+ ΔI2.

[0111] The method for determining the position information of the cut according to the composite signal in the step S5 can include: determining the position of the cut according to the peak value information of the composite signal.

[0112] The wafer detection method of the embodiment can be applied in wafer warping defect judgment. Specifically, the first difference value and the second difference value are evaluated respectively, and when the first difference value exceeds the first preset range and / or the second difference value exceeds the second preset range, it is judged that the wafer has a warping defect and an alarm is issued. In this way, the wafer with a warping defect can be prevented from entering the machine table, further improving the problem of wafer slide or placement position offset in the machine table, improving the detection accuracy of the wafer and / or the production yield of the product, and having real-time performance.

[0113] Embodiment five

[0114] The wafer detection method provided in the embodiment uses the wafer detection device in Embodiment 2 to detect a notch defect of a wafer having a protective layer formed on a surface of the wafer, the wafer having a cutout in an edge region of the wafer, the protective layer extending from the surface of the wafer to cover an area where the cutout is located, and the protective layer being a transparent or translucent material.

[0115] Reference Figure 7 The wafer detection method of the embodiment includes:

[0116] S1, emitting a detection light beam from a first surface side of the wafer to the edge region of the wafer;

[0117] S2, receiving a transmission light beam generated by the detection light beam transmitting through the wafer and the protective layer at a second surface side of the wafer, and converting the transmission light beam into a transmission signal, the second surface being opposite to the first surface in orientation;

[0118] S3, receiving a reflection light beam generated by the detection light beam reflecting through the wafer and the protective layer at the first surface side of the wafer, and converting the reflection light beam into a reflection signal;

[0119] S4, fitting the transmission signal and the reflection signal to form a composite signal; and

[0120] S5, when there is a peak value of a numerical value that is not equal in the composite signal, determining that there is a notch defect in the edge region of the wafer and issuing an alarm.

[0121] For example, step S1 can be performed by the signal emitting unit 201 in the above embodiment. Step S2 can be performed by the first signal receiving unit 202 in the above embodiment. Step S3 can be performed by the second signal receiving unit 203 in the above embodiment. Step S4 can be performed by the data processing unit 204 in the above embodiment. Step S5 can be performed by the feedback control unit 205 in the above embodiment.

[0122] The method of fitting the transmission signal and the reflection signal to form a composite signal can include: for the same time point, calculating an absolute value of a difference between an instantaneous intensity value of the transmission signal and a transmission signal intensity reference value to obtain a first difference value, calculating an absolute value of a difference between an instantaneous intensity value of the reflection signal and a reflection signal intensity reference value to obtain a second difference value, and superimposing the first difference value and the second difference value at the same time point to form a composite signal.

[0123] For example, the intensity value of the transmission signal generated when the detection light beam irradiates the non-cutout region of the wafer is taken as the transmission signal intensity reference value I BSL1The intensity value of the reflection signal generated when the detection light beam is irradiated on the non-cut region of the wafer is detected as the reflection signal intensity reference value I BSL2 ; for the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, the first difference ΔI1 = |I1-I BSL1 |, the second difference ΔI2 = |I2-I BSL2 |, and the instantaneous intensity value of the composite signal I 复合 = ΔI1 + ΔI2.

[0124] The wafer detection method of the embodiment can be applied in wafer warping defect judgment. Specifically, the first difference and the second difference are evaluated respectively, and when the first difference exceeds the first preset range and / or the second difference exceeds the second preset range, it is judged that the wafer has a warping defect and an alarm is issued.

[0125] Embodiment six

[0126] The embodiment provides a wafer detection method. The wafer detection method uses the wafer detection device of the above-mentioned embodiment to perform pre-alignment and notch defect detection on a wafer with a protective layer formed on the surface, the edge region of the wafer has a cut, the protective layer extends from the surface of the wafer to cover the region where the cut is located, and the protective layer is a transparent or translucent material.

[0127] The wafer detection method of the embodiment comprises:

[0128] S1, emitting a detection light beam from the first surface side of the wafer to the edge region of the wafer;

[0129] S2, receiving a transmission light beam generated by the detection light beam transmitting through the wafer and the protective layer on the second surface side of the wafer, and converting the transmission light beam into a transmission signal, the second surface being opposite to the first surface in orientation;

[0130] S3, receiving a reflection light beam generated by the detection light beam reflecting through the wafer and the protective layer on the first surface side of the wafer, and converting the reflection light beam into a reflection signal;

[0131] S4, fitting the transmission signal and the reflection signal to form a composite signal; and

[0132] S5, determining the position information of the cut according to the composite signal, and making the cut stay at a preset position to realize pre-alignment of the wafer, and judging that the edge region of the wafer has a notch defect and issuing an alarm when there are non-equal peak values in the composite signal.

[0133] It should be noted that the same parts of the wafer detection method provided in the embodiment and the embodiments four and five can be seen from the above, and will not be repeated here.

[0134] Compared with the prior art, the wafer detection device and the wafer detection method provided by the present application can form a composite signal by fitting the transmission signal of one side of the wafer and the reflection signal of the other side of the wafer, which is equivalent to amplifying the intensity of the transmission light beam and the reflection light beam, and can meet the detection requirements of the wafer with a transparent or semi-transparent protective layer on the surface (including the pre-alignment requirement and / or the gap defect detection requirement), and has high detection accuracy, which is beneficial to improve the problem of wafer sliding or placement position offset in the workbench, and improve the detection accuracy of the wafer and / or the production yield of the product.

[0135] In addition, the overall device structure of the wafer detection device of the present application is simple, convenient to manufacture, high in stability and reliability, and can be used for a long time, which is beneficial to improve the production efficiency of the factory.

[0136] It should be noted that spatial relationship terms such as "under", "below", "lower", "underneath", "above", "upper" and the like are used herein for the convenience of description to describe the relationship between one element or feature and other elements or features shown in the drawings. It should be understood that in addition to the orientation shown in the drawings, the spatial relationship terms are also intended to include different orientations of the device in use and operation. For example, if the device in the drawings is turned over, then the element or feature described as "under" or "below" or "under" the other element will be oriented "above" the other element or feature. Therefore, the exemplary terms "under" and "below" can include both the upper and lower orientations. The device can be additionally oriented (rotated 90 degrees or other orientations), and the spatial description used herein is correspondingly interpreted.

[0137] It can be understood that although the terms "first", "second" and the like are used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed can be referred to as the second component, region, layer and / or part without deviating from some embodiments of the present application.

[0138] The various modules and units (signal emitting unit, first signal receiving unit, second signal receiving unit, data processing unit and data processing unit) of the wafer detection device of the present application can be combined in one module, or any one unit can be split into multiple sub-units, or at least part of the function of one or more of these units can be combined with at least part of the function of other units, and realized in one module.

[0139] It should be noted that the description is in a progressive manner, and the parts described later focus on the mutual reference.

[0140] The above description is only a description of the preferred embodiments of the present application, and does not limit the scope of the present application in any way. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present application without departing from the spirit and scope of the present application by using the disclosed methods and technical contents. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solutions of the present application, are within the protection scope of the present application.

Claims

1. A wafer inspection device, characterized in that, For pre-aligning a wafer with a protective layer formed on its surface, the wafer has a notch at its edge, the protective layer extends from the surface of the wafer to cover the area where the notch is located, and the protective layer is a transparent or translucent material; the wafer inspection device includes: A signal transmitting unit, located on one side of the first surface of the wafer, is used to emit a detection beam toward the edge region of the wafer; A first signal receiving unit is located on one side of the second surface of the wafer, the second surface being opposite to the orientation of the first surface. The first signal receiving unit is used to receive the transmitted light beam generated by the detection beam passing through the wafer and the protective layer, and to output a transmission signal. The second signal receiving unit is located on one side of the first surface of the wafer, and is used to receive the reflected beam generated by the detection beam after being reflected by the wafer and the protective layer, and to output the reflected signal. A data processing unit is configured to receive the transmitted signal and the reflected signal, and fit the transmitted signal and the reflected signal to form a composite signal; and The feedback control unit is used to determine the position information of the notch based on the composite signal and keep the notch at a preset position to achieve the pre-alignment of the wafer.

2. The wafer inspection apparatus as described in claim 1, characterized in that, The data processing unit fits the transmitted signal and the reflected signal to form a composite signal by: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmitted signal and the reference value of the transmitted signal intensity to obtain a first difference value; calculating the absolute value of the difference between the instantaneous intensity value of the reflected signal and the reference value of the reflected signal intensity to obtain a second difference value; and superimposing the first difference value and the second difference value at the same time point to form a composite signal. The feedback control unit determines the position information of the incision based on the peak value information of the composite signal.

3. The wafer inspection apparatus as described in claim 2, characterized in that, The intensity value of the transmission signal generated when the detection beam irradiates the non-notched area of ​​the wafer is used as the transmission signal intensity reference value I. BSL1 The intensity value of the reflected signal generated when the detection beam illuminates the non-notched area of ​​the wafer is used as the reference value I of the reflected signal intensity. BSL2 ; For the same point in time, the instantaneous intensity value of the transmitted signal is I1, and the instantaneous intensity value of the reflected signal is I2. The first difference ΔI1 = |I1 - I BSL1 |, the second difference ΔI2=|I2-I BSL2 |, the instantaneous intensity value I of the composite signal 复合＝ ΔI 1+ ΔI2.

4. The wafer inspection apparatus according to any one of claims 1-3, characterized in that, The wafer inspection device also includes a worktable for placing the wafer; during the process of determining the kerf, the worktable drives the wafer to rotate; the feedback control unit controls the rotation of the worktable according to the position information of the kerf so that the kerf stops at a preset position, thereby achieving pre-alignment of the wafer.

5. A wafer inspection device, characterized in that, For detecting notch defects on wafers with a protective layer formed on their surface, the wafer has notches in its edge region, the protective layer extends from the surface of the wafer and covers the area where the notches are located, and the protective layer is a transparent or translucent material; the wafer inspection device includes: A signal transmitting unit, located on one side of the first surface of the wafer, is used to emit a detection beam toward the edge region of the wafer; A first signal receiving unit is located on one side of the second surface of the wafer, the second surface being opposite to the orientation of the first surface. The first signal receiving unit is used to receive the transmitted light beam generated by the detection beam passing through the wafer and the protective layer, and to output a transmission signal. The second signal receiving unit is located on one side of the first surface of the wafer, and is used to receive the reflected beam generated by the detection beam after being reflected by the wafer and the protective layer, and to output the reflected signal. A data processing unit is configured to receive the transmitted signal and the reflected signal, and fit the transmitted signal and the reflected signal to form a composite signal; and The feedback control unit is used to determine that there is a notch defect in the edge region of the wafer and issue an alarm when there are high peak values ​​with unequal values ​​in the composite signal.

6. The wafer inspection apparatus as described in claim 5, characterized in that, The data processing unit fits the transmitted signal and the reflected signal to form a composite signal by: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmitted signal and the reference value of the transmitted signal intensity to obtain a first difference value; calculating the absolute value of the difference between the instantaneous intensity value of the reflected signal and the reference value of the reflected signal intensity to obtain a second difference value; and superimposing the first difference value and the second difference value at the same time point to form a composite signal.

7. The wafer inspection apparatus as described in claim 6, characterized in that, The intensity value of the transmission signal generated when the detection beam irradiates the non-notched area of ​​the wafer is used as the transmission signal intensity reference value I. BSL1 The intensity value of the reflected signal generated when the detection beam illuminates the non-notched area of ​​the wafer is used as the reference value I of the reflected signal intensity. BSL2 ; For the same point in time, the instantaneous intensity value of the transmitted signal is I1, and the instantaneous intensity value of the reflected signal is I2. The first difference ΔI1 = |I1 - I BSL1 |, the second difference ΔI2=|I2-I BSL2 |, the instantaneous intensity value I of the composite signal 复合＝ ΔI 1+ ΔI2.

8. The wafer inspection apparatus according to any one of claims 5-7, characterized in that, The wafer inspection device also includes a worktable for placing the wafer; during the process of determining the notch defect, the worktable drives the wafer to rotate.

9. The wafer inspection apparatus according to any one of claims 2-3 or 6-7, used in the determination of wafer warpage defects; characterized in that, The data processing unit transmits the first difference and the second difference at each time point to the feedback control unit. The feedback control unit evaluates the first difference and the second difference respectively. When the first difference exceeds the first preset range and / or the second difference exceeds the second preset range, it determines that the wafer has a warping defect and issues an alarm.

10. A wafer inspection method, characterized in that, The wafer inspection apparatus as described in any one of claims 1-4 is used to pre-align a wafer with a protective layer formed on its surface, wherein the edge region of the wafer has a notch, the protective layer extends from the surface of the wafer to cover the area where the notch is located, and the protective layer is a transparent or translucent material; the wafer inspection method includes: A detection beam is emitted from one side of the first surface of the wafer toward the edge region of the wafer; The device receives a transmitted light beam generated by the detection beam passing through the wafer and the protective layer on one side of the second surface of the wafer, and converts the transmitted light beam into a transmitted signal. The second surface is oriented opposite to the first surface. The device receives a reflected beam generated by the detection beam reflected by the wafer and the protective layer on one side of the first surface of the wafer, and converts the reflected beam into a reflected signal. The transmitted signal and the reflected signal are fitted to form a composite signal; and The position information of the notch is determined based on the composite signal, and the notch is kept at a preset position to achieve the pre-alignment of the wafer.

11. The wafer inspection method as described in claim 10, characterized in that, The method for fitting the transmitted signal and the reflected signal to form a composite signal includes: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmitted signal and the reference value of the transmitted signal intensity to obtain a first difference value; calculating the absolute value of the difference between the instantaneous intensity value of the reflected signal and the reference value of the reflected signal intensity to obtain a second difference value; and superimposing the first difference value and the second difference value at the same time point to form a composite signal. The method for determining the position information of the incision based on the composite signal includes: determining the position of the incision based on the peak value information of the composite signal.

12. The wafer inspection method as described in claim 11, characterized in that, The intensity value of the transmission signal generated when the detection beam irradiates the non-notched area of ​​the wafer is used as the transmission signal intensity reference value I. BSL1 The intensity value of the reflected signal generated when the detection beam illuminates the non-notched area of ​​the wafer is used as the reference value I of the reflected signal intensity. BSL2 ; For the same point in time, the instantaneous intensity value of the transmitted signal is I1, and the instantaneous intensity value of the reflected signal is I2. The first difference ΔI1 = |I1 - I BSL1 |, the second difference ΔI2=|I2-I BSL2 |, the instantaneous intensity value I of the composite signal 复合＝ ΔI 1+ ΔI2.

13. A wafer inspection method, characterized in that, The wafer inspection apparatus according to any one of claims 5-8 is used to inspect for notches on a wafer with a protective layer formed on its surface, wherein the edge region of the wafer has a notch, the protective layer extends from the surface of the wafer to cover the area where the notch is located, and the protective layer is a transparent or translucent material; the wafer inspection method includes: A detection beam is emitted from one side of the first surface of the wafer toward the edge region of the wafer; The device receives a transmitted light beam generated by the detection beam passing through the wafer and the protective layer on one side of the second surface of the wafer, and converts the transmitted light beam into a transmitted signal. The second surface is oriented opposite to the first surface. The device receives a reflected beam generated by the detection beam reflected by the wafer and the protective layer on one side of the first surface of the wafer, and converts the reflected beam into a reflected signal. The transmitted signal and the reflected signal are fitted to form a composite signal; and When the composite signal has peak values ​​that are not equal, it is determined that there is a notch defect in the edge region of the wafer and an alarm is issued.

14. The wafer inspection method as described in claim 13, characterized in that, The method for fitting the transmitted signal and the reflected signal to form a composite signal includes: for the same time point, calculating the absolute value of the difference between the instantaneous intensity value of the transmitted signal and the reference value of the transmitted signal intensity to obtain a first difference value; calculating the absolute value of the difference between the instantaneous intensity value of the reflected signal and the reference value of the reflected signal intensity to obtain a second difference value; and superimposing the first difference value and the second difference value at the same time point to form a composite signal.

15. The wafer inspection method as described in claim 14, characterized in that, The intensity value of the transmission signal generated when the detection beam irradiates the non-notched area of ​​the wafer is used as the transmission signal intensity reference value I. BSL1 The intensity value of the reflected signal generated when the detection beam illuminates the non-notched area of ​​the wafer is used as the reference value I of the reflected signal intensity. BSL2 ; For the same point in time, the instantaneous intensity value of the transmitted signal is I1, and the instantaneous intensity value of the reflected signal is I2. The first difference ΔI1 = |I1 - I BSL1 |, the second difference ΔI2=|I2-I BSL2 |, the instantaneous intensity value I of the composite signal 复合＝ ΔI 1+ ΔI2.

16. The wafer inspection method as described in any one of claims 11-12 or 14-15, applied in the determination of wafer warpage defects; characterized in that, The first difference and the second difference are evaluated respectively. If the first difference exceeds the first preset range and / or the second difference exceeds the second preset range, it is determined that the wafer has a warping defect and an alarm is issued.

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