Wafer detection device and method

Abstract

The invention provides a wafer detection device. In the wafer detection device, a signal transmitting unit is located on one side of a first surface of a wafer and transmits a detection light beam to an edge area of the wafer; the first signal receiving unit is located on one side of the second surface of the wafer, receives and detects transmission light beams generated when the detection light beams penetrate through the wafer and the protective layer and outputs transmission signals; the second signal receiving unit is located on one side of the first surface of the wafer, receives and detects a reflected light beam generated by reflection of the detection light beam through the wafer and the protective layer, and outputs a reflected signal; the data processing unit fits the received transmission signal and reflection signal to form a composite signal; and the feedback control unit determines position information of a wafer notch according to the composite signal, and enables the notch to stay at a preset position, thereby realizing pre-alignment of the wafer. The wafer detection device can meet the pre-alignment requirement of the wafer of which the surface is pasted with a transparent or semitransparent protection layer. The invention also provides a wafer detection method.

Description

Technical Field

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

[0002] In the process of wafer production, the measurement and inspection machines and some process machines need to use the pre-aligner to find the notch on the edge of the wafer to pre-align the wafer before production begins, so as to ensure that the inspection area can be accurately found during inspection, and to ensure that during production, the process machine can use the notch position to implement the deposition process or ion implantation process of the fixed crystal phase. If the notch of the wafer cannot be confirmed or is confirmed incorrectly, it will directly affect the inspection accuracy and product electrical performance.

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

[0004] In the process after the glass plate is attached to the front of the wafer, when the traditional method of finding the wafer cut is used to find the wafer cut, the strength of the received feedback signal is seriously reduced due to the influence of the glass plate. The wafer cut cannot be determined based on the feedback signal or the positioning accuracy of the cut is low, causing the wafer to slip or shift in the placement position on the workbench, affecting the wafer detection accuracy and product production yield. In addition, the traditional method of finding the wafer cut cannot detect the notch defect on the edge of the wafer. Summary of the invention

[0005] The present invention 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 with transparent or translucent protective layers such as glass plates attached to the surface, and have high pre-alignment accuracy and defect detection accuracy, which is beneficial to improving the problem of wafer sliding or placement position deviation in a workbench, and improving the wafer detection accuracy and product production yield.

[0006] In order to achieve the above-mentioned purpose, the present application provides a wafer detection device. The wafer detection device is used to pre-align 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 a transparent or translucent material. The wafer detection device includes:

[0007] A signal emitting unit, located on one side of the first surface of the wafer, and configured to emit a detection light beam to an edge region of the wafer;

[0008] A first signal receiving unit is located at a second surface side of the wafer, the second surface is opposite to the first surface, and the first signal receiving unit is used to receive a transmission light beam generated by the detection light beam passing through the wafer and the protective layer, and output a transmission signal;

[0009] A second signal receiving unit, located on one side of the first surface of the wafer, is used to receive and detect a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and output a reflection signal;

[0010] a data processing unit, configured to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal; and

[0011] A feedback control unit is used to determine the position information of the incision according to the composite signal, and to make the incision stay at a preset position to achieve pre-alignment of the wafer.

[0012] Optionally, the data processing unit fits the transmission signal and the reflection signal to form a composite signal, comprising: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal;

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

[0014] Optionally, the intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected 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, and the first difference ΔI1=|I1-IBSL1 |, the second difference ΔI2=|I2-I BSL2 |, the instantaneous intensity value I of the composite signal 复合 =ΔI 1+ ΔI2.

[0015] Optionally, the wafer detection device also includes a workbench, which is used to place the wafer; in the process of determining the incision, the workbench drives the wafer to rotate; the feedback control unit controls the rotation of the workbench according to the position information of the incision so that the incision stays at a preset position, thereby achieving pre-alignment of the wafer.

[0016] The present invention also provides a wafer detection device. The wafer detection device is used to detect notch defects on a wafer with a protective layer formed on the surface, the edge area of ​​the wafer has a cut, the protective layer extends from the surface of the wafer to cover the area where the cut is located, and the protective layer is a transparent or translucent material. The wafer detection device includes: a signal transmitting unit, located on the first surface side of the wafer, used to transmit a detection beam to the edge area of ​​the wafer; a first signal receiving unit, located on the second surface side of the wafer, the second surface is opposite to the first surface, the first signal receiving unit is used to receive and detect the transmission beam generated by the detection beam passing through the wafer and the protective layer, and output a transmission signal; a second signal receiving unit, located on the first surface side of the wafer, used to receive and detect the reflection beam generated by the detection beam reflected by the wafer and the protective layer, and output a reflection signal; a data processing unit, used to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal; and a feedback control unit, used to judge that there is a notch defect in the edge area of ​​the wafer and issue an alarm when there is a high peak value with unequal values ​​in the composite signal.

[0017] Optionally, the data processing unit fits the transmission signal and the reflection signal to form a composite signal, including: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

[0018] Optionally, the intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected signal intensity reference value I BSL2For the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, and 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.

[0019] Optionally, the wafer inspection device further includes a workbench, which is used to place the wafer; during the process of determining the notch defect, the workbench drives the wafer to rotate.

[0020] Optionally, the wafer detection device is used in wafer warping defect judgment; the data processing unit transmits the first difference and the second difference at each time point to the feedback control unit, and the feedback control unit evaluates the first difference and the second difference respectively, and 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 a warping defect and an alarm is issued.

[0021] The present invention also provides a wafer detection method. The wafer detection method uses the above-mentioned wafer detection device to pre-align 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 a transparent or translucent material. The wafer detection method includes:

[0022] emitting a detection light beam from a first surface side of the wafer toward an edge region of the wafer;

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

[0024] Receiving, on one side of the first surface of the wafer, a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and converting the reflected light beam into a reflection signal;

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

[0026] The position information of the cut is determined according to the composite signal, and the cut is made to stay at a preset position to achieve pre-alignment of the wafer.

[0027] Optionally, the method of fitting the transmission signal and the reflection 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 transmission signal and the transmission signal intensity reference value to obtain a first difference, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal;

[0028] The method for determining the position information of the cutout according to the composite signal includes: 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 light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected 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, and 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.

[0030] The present invention also provides a wafer inspection method. The wafer inspection method uses the above-mentioned wafer inspection device to perform notch defect inspection on 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 a transparent or translucent material; the wafer inspection method includes:

[0031] emitting a detection light beam from a first surface side of the wafer toward an edge region of the wafer;

[0032] receiving, on a second surface side of the wafer, a transmission light beam generated by the detection light beam passing through the wafer and the protective layer, and converting the transmission light beam into a transmission signal, wherein the second surface is opposite to the first surface;

[0033] Receiving, on one side of the first surface of the wafer, a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and converting the reflected light beam into a reflection signal;

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

[0035] When the composite signal has high peak values ​​with unequal values, it is determined that a notch defect exists in the edge area of ​​the wafer and an alarm is issued.

[0036] Optionally, the method of fitting the transmission signal and the reflection 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 transmission signal and the transmission signal intensity reference value to obtain a first difference, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

[0037] Optionally, the intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected 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, and 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.

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

[0039] Compared with the prior art that determines the incision position of the wafer only based on the light signal received on one side of the wafer, in the wafer detection device and wafer detection method provided by the present invention, the transmission signal on one side of the wafer and the reflection signal on the other side of the wafer are fitted to form a composite signal, which is equivalent to amplifying the intensity of the transmitted light beam and the reflected light beam. It can meet the detection requirements of wafers with a transparent or translucent protective layer attached to the surface (including pre-alignment requirements and / or notch defect detection requirements), and has high detection accuracy, which is conducive to improving the problem of wafer sliding or placement position deviation in the workbench, and improving the wafer detection accuracy and product production yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of a wafer inspection device provided by the present invention.

[0041] Figure 2The figure is a schematic diagram of a signal curve obtained by inspecting a cut of a wafer using a wafer inspection device provided by an embodiment of the present invention.

[0042] Figure 3 The figure is a schematic diagram of a signal curve obtained by inspecting a wafer with a notch defect using a wafer inspection device provided by an embodiment of the present invention.

[0043] Figure 4 The figure is a schematic diagram of a signal curve obtained by using a wafer detection device according to an embodiment of the present invention to detect a wafer with a center-upward warp.

[0044] Figure 5 The figure is a schematic diagram of a signal curve obtained by using a wafer inspection device according to an embodiment of the present invention to inspect a wafer with an edge that is warped upward.

[0045] Figure 6 A schematic flow chart of a wafer inspection method provided by an embodiment of the present invention.

[0046] Figure 7 A schematic flow chart of a wafer inspection method provided in another embodiment of the present invention.

[0047] Description of reference numerals:

[0048] 100 - wafer; 100a - incision; 101 - protective layer; 201 - signal transmitting 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 the wafer detection method proposed in the present invention are further described in detail below in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will become clearer. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0050] Embodiment 1

[0051] Figure 1 Schematic diagram of the wafer inspection device provided by the present invention. Figure 1 As shown, the wafer inspection device provided in this embodiment is used to pre-align a wafer 100 having a protective layer 101 formed on the surface, wherein the edge area of ​​the wafer 100 has a cutout 100a, and the protective layer 101 extends from the surface of the wafer 100 to cover the area where the cutout 100a is located, and the protective layer 101 is a transparent or translucent material.

[0052] like Figure 1As shown, the wafer detection 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. The signal transmitting unit 201 is located on the first surface side of the wafer 100, and is used to transmit a detection beam to the edge area of ​​the wafer 100. The first signal receiving unit 202 is located on the second surface side of the wafer 100, and the second surface of the wafer 100 is opposite to the first surface. The first signal receiving unit 202 is used to receive and detect the transmission beam generated by the detection beam passing 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 used to receive and detect the reflection beam generated by the detection beam reflected by the wafer 100 and the protective layer 101, and output a reflection signal. The data processing unit 204 is used 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 used to determine the position information of the incision according to the composite signal, and make the incision stay at a preset position to achieve 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 protection layer 101 covers the first surface or the second surface of the wafer 100 .

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

[0055] refer to Figure 1 As shown, the signal transmitting unit 201 may be located on the front side of the wafer 100 and transmit a detection beam to the edge area of ​​the wafer 100. When the detection beam is irradiated onto the protective layer 101 and the wafer 100, transmission and reflection may occur.

[0056] The first signal receiving unit 202 may be located on the back side of the wafer 100 , and is configured to receive a transmission light beam generated by the detection light beam passing 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 used to receive and detect a reflected light beam generated by the detection light beam being reflected by the wafer 100 and the protective layer 101 , and output a reflection 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 may be a laser transmitter, and the first signal receiving unit 202 and the second signal receiving unit 203 may both be laser receivers, but are not limited thereto.

[0059] Exemplary, reference Figure 1 As shown, the detection beam emitted by the signal emitting unit 201 can illuminate the edge area of ​​the wafer 100 vertically along the front of the wafer 100, but is not limited thereto. In other embodiments, the detection beam emitted by the signal emitting unit 201 can illuminate the edge area of ​​the wafer 100 at an angle.

[0060] Taking the detection light beam emitted by the signal emitting unit 201 irradiating the edge area of ​​the wafer 100 along the vertical direction of the front side of the wafer 100 as an example, at this time, the first signal receiving unit 202 can be set directly above the signal emitting unit 201, and the setting position of the second signal receiving unit 203 can overlap with the setting of the signal emitting unit 201, so as to facilitate the debugging of the relative positions between the signal emitting unit 201, the first signal receiving unit 202 and the second signal receiving unit 203. It should be noted that even if the setting position of the second signal receiving unit 203 overlaps with the setting of the signal emitting unit 201, the detection light beam can still irradiate the edge area of ​​the wafer 100 along the optical path set in the second signal receiving unit 203 and / or the signal emitting unit 201, and the reflected light beam can still irradiate the second signal receiving unit 203 along the optical path set in the second signal receiving unit 203 and / or the signal emitting unit 201.

[0061] In this embodiment, the wafer inspection device may further include a workbench ( Figure 1 (not shown), the workbench is used to place the wafer 100; in the process of determining the cutout 100a of the wafer, the workbench drives the wafer 100 to rotate, so that the detection beam of the signal emitting unit 201 can illuminate and scan the entire edge area of ​​the wafer 100. It should be noted that one rotation of the wafer 100 can correspond to one cycle of the transmission signal and one cycle of the reflection signal.

[0062] refer to Figure 1As 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 transmission signal output by the first signal receiving unit 202 and the reflection signal output by the second signal receiving unit 203, and then fits the transmission signal and the reflection signal to form a composite signal.

[0063] Specifically, the step of the data processing unit 204 fitting the transmission signal and the reflection 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 transmission signal and the transmission signal intensity reference value to obtain a first difference ΔI1, 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 ΔI2, and superimposing the first difference ΔI1 and the second difference ΔI2 at the same time point to form a composite signal.

[0064] Exemplarily, the intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut region 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 light beam is irradiated on the non-cut area of ​​the wafer 100 is used as the reflected 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, and 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.

[0065] Figure 2 The figure is a schematic diagram of a signal curve obtained by detecting a cut of a wafer using a wafer detection device provided by an embodiment of the present invention. Figure 2 As shown, the wafer is a normal wafer with a protective layer formed on the surface. The so-called normal wafer may refer to a wafer that is flat and has no notch defects in the edge area.

[0066] Since the intensity of the transmitted light beam generated by the detection light beam passing through the cutout area is greater than the intensity of the transmitted light beam generated by the detection light beam passing through the non-cutout area, Figure 2 As shown in FIG. 1 , for the transmission signal curve, the time when the peak value appears corresponds to the time when the detection beam irradiates the incision area, and the time when the valley value appears corresponds to the time when the detection beam irradiates the non-incision area, and the valley value of the curve can be used as the transmission signal intensity reference value I BSL1 .

[0067] Since the intensity of the reflected light beam generated by the detection light beam in the incision area is less than the intensity of the reflected light beam generated by the detection light beam in the non-incision area, the reference Figure 2 As shown in FIG. 1 , for the reflection signal curve, the time when the valley value appears corresponds to the time when the detection beam irradiates the incision area, and the time when the peak value appears corresponds to the time when the detection beam irradiates the non-incision area, and the peak value of the curve can be used as the reflection signal intensity reference value I BSL2 .

[0068] like Figure 2 As shown, in the same cycle, the time when the peak value of the transmission signal appears is the same as the time when the valley value of the reflection 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 transmission signal appears and the valley value of the reflection signal appears. According to the peak value information of the composite signal, the position information of the wafer cut can be determined. It should be noted that the peak height of the composite signal formed by the data processing unit fitting the transmission signal and the reflection signal is approximately the sum of the peak height of the transmission signal and the peak height of the reflection signal. The composite signal is equivalent to amplifying the transmission signal and the reflection signal. Then, determining the cut position of the wafer through the composite signal is conducive to improving the pre-alignment accuracy of the wafer, and can meet the pre-alignment requirements of wafers with a transparent or translucent protective layer attached to the surface.

[0069] refer to Figure 1 As shown, the wafer detection device also includes a feedback control unit 205, which is used to determine the position information of the cutout 100a according to the composite signal, and make the cutout 100a stay at a preset position to achieve pre-alignment of the wafer. Exemplarily, the feedback control unit 205 determines the position information of the cutout 100a according to the peak value information of the composite signal, and controls the rotation of the workbench according to the position information of the cutout 100a so that the cutout stays at a preset position to achieve pre-alignment of the wafer 100.

[0070] Since the wafer detection device of the present application can accurately position the wafer, the wafer pre-alignment pass rate is high when performing processes such as ion implantation that require wafer orientation, which can effectively reduce anomalies caused by failed or inaccurate wafer pre-alignment and improve process yield.

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

[0072] For example, Figure 4 FIG. 1 shows a signal curve obtained by using a wafer detection device according to an embodiment of the present invention to detect a cut of a wafer with a center warped upward. When the center of the wafer warps upward, the wafer is in an inverted dish shape on the workbench. The reflection signal curve and the transmission signal curve obtained by detecting the cut of the wafer are shown in FIG. Figure 4 As shown, the difference between the peak value of the transmission signal and the reference value of the transmission signal intensity is small, and the difference between the valley value of the reflection signal and the reference value of the reflection signal intensity is large.

[0073] For example, Figure 5 FIG. 1 shows a signal curve obtained by detecting the cut of a wafer with an edge warped upward using a wafer detection device according to an embodiment of the present invention. When the edge of the wafer warps upward, the wafer is in a dish shape on the workbench. The reflection signal curve and the transmission signal curve obtained by detecting the cut of the wafer are shown in FIG. Figure 5 As shown, the difference between the peak value of the transmission signal and the reference value of the transmission signal intensity is large, and the difference between the valley value of the reflection signal and the reference value of the reflection signal intensity is small.

[0074] The first difference 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 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 The difference ΔI1 and ΔI2 between the extreme values ​​of the transmission signal curve and the reflection signal curve and the reference value are shown as examples. Figure 4 and Figure 5 When the wafer is warped, the first difference ΔI1 and the second difference ΔI2 will deviate from the normal state. Therefore, the feedback control unit 205 evaluates the first difference ΔI1 and the second difference ΔI2 respectively. When the first difference ΔI1 exceeds the first preset range and / or the second difference ΔI2 exceeds the second preset range, it can be determined that the wafer has a warping defect.

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

[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 a normal wafer.

[0077] Embodiment 2

[0078] The wafer detection device provided in this embodiment is different from that in the first embodiment in that the feedback control unit is used to determine that there is a notch defect in the edge area of ​​the wafer and issue an alarm when the composite signal has unequal peak values. The similarities between the wafer detection device in this embodiment and the first embodiment can be found in the first embodiment and will not be repeated here.

[0079] refer to Figure 1 As shown, the wafer inspection device provided in this embodiment is used to perform notch defect detection on a wafer 100 having a protective layer 101 formed on the surface, wherein the edge area of ​​the wafer 100 has a cutout 100a, and the protective layer 101 extends from the surface of the wafer 100 to cover the area where the cutout 100a is located, and the protective layer 101 is a transparent or translucent material.

[0080] The wafer detection 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 .

[0081] The signal emitting unit 201 is located on one side of the first surface of the wafer 100 , and is used to emit a detection light beam to an 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 used to receive the transmission light beam generated by the detection light beam passing through the wafer 100 and the protective layer 101, and output a transmission signal.

[0083] The second signal receiving unit 203 is located at one side of the first surface of the wafer 100 , and is used to receive and detect a reflected light beam generated by the detection light beam being reflected by the wafer 100 and the protective layer 101 , and output a reflection signal.

[0084] The data processing unit 204 is used 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 area of ​​the wafer and issue an alarm when the composite signal has high peak values ​​with unequal values.

[0086] Specifically, the data processing unit 204 fits the transmission signal and the reflection signal to form a composite signal, which may include: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

[0087] Exemplarily, the intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut region 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 light beam is irradiated on the non-cut area of ​​the wafer 100 is used as the reflected 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, and 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.

[0088] Figure 3 The figure is a schematic diagram of the signal curve obtained by using the wafer detection device provided by one embodiment of the present invention to detect a wafer with a notch defect. When there is a notch defect in the edge area of ​​the wafer, that is, there are other notches in the edge area of ​​the wafer except the cut, the cut of the wafer is detected to obtain the reflection signal curve, transmission signal curve and composite signal curve as shown in FIG. Figure 3 As shown, the reflection signal curve has valley values ​​with unequal values, and the transmission signal curve has high peak values ​​with unequal values, that is, both the reflection signal curve and the transmission signal curve have noise peaks, so the composite signal curve formed by fitting also has noise peaks (that is, there are high peak values ​​with unequal values). Therefore, when the feedback control unit 205 finds that the composite signal has high peak values ​​with unequal values, the feedback control unit 205 can determine that there is a notch defect in the edge area of ​​the wafer 100.

[0089] When the feedback control unit 205 finds that there is a notch defect in the edge area of ​​the wafer and alarms, the wafer with the notch defect can be prevented from entering the machine, and the problem of the wafer sliding or placing position deviation in the workbench can be further improved, and the detection accuracy of the wafer and / or the production yield of the product can be improved in real time. Furthermore, the feedback control unit 205 can also determine the position of the notch defect according to the composite signal, that is, determine the position of the notch defect according to the mixed peak of the composite signal, so that the coordinate accuracy of the notch defect can be improved, which is convenient for the review tool to locate and take pictures of the notch defect, so as to analyze the notch defect and formulate improvement directions.

[0090] In this embodiment, the wafer detection device can be used in wafer warpage defect judgment, that is, the wafer detection device has the function of judging wafer warpage. Specifically, the data processing unit 204 of the wafer detection device can transmit the first difference ΔI1 and the second difference ΔI2 at each time point to the feedback control unit 205, and the feedback control unit 205 evaluates the first difference ΔI1 and the second difference ΔI2 respectively. When the first difference ΔI1 exceeds the first preset range and / or the second difference ΔI2 exceeds the second preset range, it is judged that the wafer has a warpage defect and an alarm is issued.

[0091] Embodiment 3

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

[0093] The wafer detection 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 emitting unit 201 is located on one side of the first surface of the wafer 100 , and is used to emit a detection light beam to an edge region of the wafer 100 .

[0095] 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 used to receive the transmission light beam generated by the detection light beam passing through the wafer 100 and the protective layer 101, and output a transmission signal.

[0096] The second signal receiving unit 203 is located at one side of the first surface of the wafer 100 , and is used to receive and detect a reflected light beam generated by the detection light beam being reflected by the wafer 100 and the protective layer 101 , and output a reflection signal.

[0097] The data processing unit 204 is used to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal.

[0098] The feedback control unit 205 is used to determine the position information of the cut 100a of the wafer according to the composite signal, and make the cut 100a stay at a preset position to achieve pre-alignment of the wafer 100. The feedback control unit 205 is used to determine whether there is a notch defect in the edge area of ​​the wafer 100 and issue an alarm when there are high peak values ​​with unequal values ​​in the composite signal.

[0099] It should be noted that the similarities between the wafer inspection device provided in this embodiment and the first and second embodiments can be found above and will not be repeated here.

[0100] Embodiment 4

[0101] The present embodiment provides a wafer detection method, which uses the wafer detection device in Example 1 to pre-align a wafer having a protective layer formed on the surface, wherein the edge area of ​​the wafer has a cut, and the protective layer extends from the surface of the wafer to cover the area where the cut is located, and the protective layer is a transparent or translucent material.

[0102] Figure 6 FIG. 1 is a flow chart of a wafer inspection method provided by an embodiment of the present invention. Figure 6 As shown, the wafer detection method includes:

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

[0104] S2, receiving and detecting a transmission light beam generated by the detection light beam passing through the wafer and the protective layer on a second surface side of the wafer, and converting the transmission light beam into a transmission signal, wherein the second surface is opposite to the first surface;

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

[0106] S4, fitting the transmission signal and the reflection signal to form a composite signal; and

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

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

[0109] In this embodiment, the method of fitting the transmission signal and the reflection signal to form a composite signal in step S4 may include: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

[0110] Exemplarily, the intensity value of the transmission signal generated when the detection beam is irradiated on the non-cut 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 is irradiated on the non-cut area of ​​the wafer is used as the reference value of the reflected signal intensity 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, and 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.

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

[0112] The wafer detection method of this embodiment can be applied to the judgment of wafer warpage defects. Specifically, the first difference and the second difference are evaluated respectively. 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 warpage defect and an alarm is issued. In this way, wafers with warpage defects can be prevented from entering the machine, and the problem of wafer sliding or placement position deviation in the workbench can be further improved, thereby improving the detection accuracy of the wafer and / or the production yield of the product, and having real-time performance.

[0113] Embodiment 5

[0114] The wafer inspection method provided in this embodiment uses the wafer inspection device in Example 2 to perform notch defect detection on a wafer having a protective layer formed on the surface, wherein the edge area of ​​the wafer has a cut, and the protective layer extends from the surface of the wafer to cover the area where the cut is located, and the protective layer is a transparent or translucent material.

[0115] refer to Figure 7 As shown, the wafer detection method of this embodiment includes:

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

[0117] S2, receiving and detecting a transmission light beam generated by the detection light beam passing through the wafer and the protective layer on a second surface side of the wafer, and converting the transmission light beam into a transmission signal, wherein the second surface is opposite to the first surface;

[0118] S3, receiving, on the first surface side of the wafer, a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and converting the reflected 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 are high peak values ​​with unequal values ​​in the composite signal, it is determined that there is a notch defect in the edge area of ​​the wafer and an alarm is issued.

[0121] Exemplarily, step S1 may be performed by the signal transmitting unit 201 in the above embodiment. Step S2 may be performed by the first signal receiving unit 202 in the above embodiment. Step S3 may be performed by the second signal receiving unit 203 in the above embodiment. Step S4 may be performed by the data processing unit 204 in the above embodiment. Step S5 may 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 may include: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

[0123] Exemplarily, the intensity value of the transmission signal generated when the detection beam is irradiated on the non-cut area of ​​the wafer is used as the transmission signal intensity reference value I BSL1The intensity value of the reflected signal generated when the detection beam is irradiated on the non-cut area of ​​the wafer is used as the reference value of the reflected signal intensity 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, and 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 =ΔI1+ΔI2.

[0124] The wafer detection method of this embodiment can be applied to wafer warpage 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 warpage defect and an alarm is issued.

[0125] Embodiment 6

[0126] This embodiment provides a wafer inspection method. The wafer inspection method uses the wafer inspection device of the above embodiment to perform pre-alignment and notch defect inspection on a wafer with a protective layer formed on the surface, wherein 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 a transparent or translucent material.

[0127] The wafer detection method of this embodiment includes:

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

[0129] S2, receiving and detecting a transmission light beam generated by the detection light beam passing through the wafer and the protective layer on a second surface side of the wafer, and converting the transmission light beam into a transmission signal, wherein the second surface is opposite to the first surface;

[0130] S3, receiving, on the first surface side of the wafer, a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and converting the reflected 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 incision according to the composite signal, and making the incision stay at a preset position to achieve pre-alignment of the wafer, and when there are peak values ​​with unequal values ​​in the composite signal, determining that there is a notch defect in the edge area of ​​the wafer and issuing an alarm.

[0133] It should be noted that the similarities between the wafer inspection method provided in this embodiment and the fourth and fifth embodiments can be found above and will not be repeated here.

[0134] Compared with the prior art, in the wafer detection device and wafer detection method provided by the present invention, the transmission signal on one side of the wafer and the reflection signal on the other side of the wafer are fitted to form a composite signal, which is equivalent to amplifying the intensity of the transmitted light beam and the reflected light beam. It can meet the detection requirements of wafers with a transparent or translucent protective layer attached to the surface (including pre-alignment requirements and / or notch defect detection requirements), and has high detection accuracy, which is conducive to improving the problem of wafer sliding or placement position deviation in the workbench, and improving the wafer detection accuracy and / or product production yield.

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

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

[0137] It is understood that although the terms "first", "second", etc. 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 departing from some embodiments of the present invention.

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

[0139] It should be noted that this specification adopts a progressive description method, and some key points described later can be referred to each other.

[0140] The above description is only a description of the preferred embodiment of the present invention, and is not any limitation on the scope of rights of the present invention. Any technical personnel in this field can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A wafer inspection device, characterized in that: Used to pre-align 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 a transparent or translucent material; the wafer detection device comprises: A signal emitting unit, located on one side of the first surface of the wafer, and configured to emit a detection light beam to an edge region of the wafer; A first signal receiving unit is located at a second surface side of the wafer, the second surface is opposite to the first surface, and the first signal receiving unit is used to receive a transmission light beam generated by the detection light beam passing through the wafer and the protective layer, and output a transmission signal; A second signal receiving unit, located on one side of the first surface of the wafer, is used to receive and detect a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and output a reflection signal; a data processing unit, configured to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal; and A feedback control unit is used to determine the position information of the incision according to the composite signal, and to make the incision stay at a preset position to achieve pre-alignment of the wafer.

2. The wafer inspection device according to claim 1, characterized in that: The data processing unit fits the transmission signal and the reflection signal to form a composite signal, comprising: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal; The feedback control unit determines the position information of the cutout according to the peak value information of the composite signal.

3. The wafer inspection device according to claim 2, characterized in that: The intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected signal intensity reference value I BSL2 ; At the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, and 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 device according to any one of claims 1 to 3, characterized in that: The wafer detection device also includes a workbench, which is used to place the wafer; in the process of determining the incision, the workbench drives the wafer to rotate; the feedback control unit controls the rotation of the workbench according to the position information of the incision so that the incision stays at a preset position, thereby achieving pre-alignment of the wafer.

5. A wafer inspection device, characterized in that: Used to detect notch defects on a wafer with a protective layer formed on the surface, the edge area 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 detection device includes: A signal emitting unit, located on one side of the first surface of the wafer, and configured to emit a detection light beam to an edge region of the wafer; A first signal receiving unit is located at a second surface side of the wafer, the second surface is opposite to the first surface, and the first signal receiving unit is used to receive a transmission light beam generated by the detection light beam passing through the wafer and the protective layer, and output a transmission signal; A second signal receiving unit, located on one side of the first surface of the wafer, is used to receive and detect a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and output a reflection signal; a data processing unit, configured to receive the transmission signal and the reflection signal, and fit the transmission signal and the reflection signal to form a composite signal; and The feedback control unit is used to determine whether a notch defect exists in the edge area of ​​the wafer and issue an alarm when the composite signal has high peak values ​​with unequal values.

6. The wafer inspection device according to claim 5, characterized in that: The data processing unit fits the transmission signal and the reflection signal to form a composite signal, including: 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, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

7. The wafer inspection device according to claim 6, characterized in that: The intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected signal intensity reference value I BSL2 ; At the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, and 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 device according to any one of claims 5 to 7, characterized in that: The wafer detection device also includes a workbench, which is used to place the wafer; during the process of determining the notch defect, the workbench drives the wafer to rotate.

9. Application of the wafer detection device according to any one of claims 2-3 or claims 6-7 in wafer warpage defect judgment; characterized in that: The data processing unit transmits the first difference and the second difference at each time point to the feedback control unit, and the feedback control unit evaluates the first difference and the second difference respectively. When the first difference exceeds a first preset range and / or the second difference exceeds a second preset range, it is determined that the wafer has a warping defect and an alarm is issued.

10. A wafer detection method, characterized in that: A wafer having a protective layer formed on the surface is pre-aligned using the wafer detection device according to any one of claims 1 to 4, wherein 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 a transparent or translucent material; the wafer detection method comprises: emitting a detection light beam from a first surface side of the wafer toward an edge region of the wafer; receiving, on a second surface side of the wafer, a transmission light beam generated by the detection light beam passing through the wafer and the protective layer, and converting the transmission light beam into a transmission signal, wherein the second surface is opposite to the first surface; Receiving, on one side of the first surface of the wafer, a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and converting the reflected light beam into a reflection signal; Fitting the transmission signal and the reflection signal to form a composite signal; and The position information of the cut is determined according to the composite signal, and the cut is made to stay at a preset position to achieve pre-alignment of the wafer.

11. The wafer detection method according to claim 10, characterized in that: The method for fitting the transmission signal and the reflection signal to form a composite 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 composite signal; The method for determining the position information of the cutout according to the composite signal includes: determining the position information of the cutout according to the peak value information of the composite signal.

12. The wafer inspection method according to claim 11, characterized in that: The intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected signal intensity reference value I BSL2 ; At the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, and 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 detection method, characterized in that: Using the wafer inspection device as described in any one of claims 5 to 8, a wafer having a protective layer formed on the surface is subjected to notch defect inspection, wherein the edge area 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 comprises: emitting a detection light beam from a first surface side of the wafer toward an edge region of the wafer; receiving, on a second surface side of the wafer, a transmission light beam generated by the detection light beam passing through the wafer and the protective layer, and converting the transmission light beam into a transmission signal, wherein the second surface is opposite to the first surface; Receiving, on one side of the first surface of the wafer, a reflected light beam generated by the detection light beam being reflected by the wafer and the protective layer, and converting the reflected light beam into a reflection signal; Fitting the transmission signal and the reflection signal to form a composite signal; and When the composite signal has high peak values ​​with unequal values, it is determined that a notch defect exists in the edge area of ​​the wafer and an alarm is issued.

14. The wafer inspection method according to claim 13, characterized in that: The method of fitting the transmission signal and the reflection 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 transmission signal and the transmission signal intensity reference value to obtain a first difference, 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, and superimposing the first difference and the second difference at the same time point to form a composite signal.

15. The wafer inspection method according to claim 14, characterized in that: The intensity value of the transmission signal generated when the detection light beam is irradiated on the non-cut 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 light beam is irradiated on the non-cut area of ​​the wafer is used as the reflected signal intensity reference value I BSL2 ; At the same time point, the instantaneous intensity value of the transmission signal is I1, the instantaneous intensity value of the reflection signal is I2, and 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 detection method according to any one of claims 11-12 or 14-15, used in wafer warpage defect judgment; characterized in that: The first difference and the second difference are evaluated respectively, and when the first difference exceeds a first preset range and / or the second difference exceeds a second preset range, it is determined that the wafer has a warping defect and an alarm is issued.

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