Method and device for detecting metal impurity content of wafer

Abstract

The invention relates to a wafer metal impurity content detection method and a wafer metal impurity content detection device. The detection method comprises the following steps: irradiating a target wafer with laser to excite metal impurities in the target wafer to the surface layer of the target wafer; sequentially carrying out oxidation treatment and etching treatment on the surface layer of the target wafer; and collecting the metal impurities deposited on the surface of the target wafer by adopting the chemical vapor decomposition liquid, and then detecting the content of the metal impurities in the chemical vapor decomposition liquid. According to the detection method, the metal impurities in the wafer can be excited to the surface layer of the target wafer by utilizing laser irradiation, so that the metal impurities in the wafer and on the surface layer can be comprehensively collected subsequently, the metal impurities of the wafer can be accurately detected, and the distribution and concentration of the metal impurities of the wafer body can be accurately reflected; and later wafer quality control is facilitated.

Description

Technical Field

[0001] The present application relates to the field of semiconductor production technology, and in particular to a method and device for detecting the metal impurity content of a wafer. Background Art

[0002] With the rapid development of the semiconductor industry, the integration of integrated circuits continues to increase. As the base material of integrated circuits, the quality of wafers is directly related to the performance and reliability of integrated circuits. In the preparation process of wafers, such as in the polishing process, the presence of metal impurities is an issue that cannot be ignored. Metal impurities such as iron, copper, nickel, etc., will seriously affect the performance of semiconductor devices, causing device performance degradation or even failure. Therefore, the detection of metal impurities in wafers becomes particularly important.

[0003] At present, the following methods are mainly used to detect the metal impurity content in wafers: first drop VPD (Vapor Phase Decomposition) solution on the wafer surface to dissolve the metal on the wafer surface, and then use ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) or TXRF (Total X-Ray Fluorescence) to analyze the composition of the VPD droplets, and determine the metal impurity content on the wafer surface based on the analysis results. However, the detection accuracy of this detection method is not high, which is not conducive to the control of wafer quality in the later stage. Summary of the invention

[0004] Based on this, it is necessary to provide a method and device for detecting the metal impurity content of a wafer in response to the above technical problems.

[0005] A method for detecting metal impurity content of a wafer, comprising:

[0006] Irradiating a laser onto a target wafer to excite metal impurities inside the target wafer to a surface layer of the target wafer;

[0007] performing oxidation treatment and etching treatment on the surface layer of the target wafer in sequence;

[0008] The metal impurities deposited on the surface of the target wafer are collected by using a chemical vapor decomposition solution, and then the content of the metal impurities in the chemical vapor decomposition solution is detected.

[0009] In one of the embodiments, during the process of the laser irradiating the target wafer, the detection method further includes: rotating and / or horizontally moving the target wafer.

[0010] In one embodiment, the wavelength of the laser is 200nm to 1100nm, and / or the power of the laser is 20mW to 300mW, and / or the angle between the laser and the surface of the target wafer is 0° to 90°, and / or the irradiation time of the laser is less than or equal to 10min.

[0011] In one embodiment, the target wafer is oxidized by using ozone, wherein the mass concentration of the ozone is greater than 99.5%;

[0012] And / or, the oxidation thickness of the target wafer surface layer is less than or equal to 10 μm.

[0013] In one of the embodiments, before the target wafer is oxidized, the detection method further comprises: heating the target wafer, wherein the heating temperature of the target wafer is less than or equal to 300°C.

[0014] A device for detecting metal impurity content of a wafer, comprising:

[0015] A support, provided with a stage for carrying a target wafer;

[0016] A laser emission module, used for emitting laser to the target wafer, so as to excite metal impurities inside the target wafer to the surface of the target wafer;

[0017] An oxidation etching module, capable of sequentially performing oxidation treatment and etching treatment on the surface layer of the target wafer;

[0018] A gas phase decomposition module capable of dropping chemical gas phase decomposition liquid onto the surface of the target wafer;

[0019] The component analysis module can collect the chemical vapor decomposition liquid containing the metal impurities on the surface of the target wafer, and perform component analysis on the chemical vapor decomposition liquid containing the metal impurities to obtain the content of the metal impurities in the chemical vapor decomposition liquid.

[0020] In one of the embodiments, the laser emitting module includes a plurality of laser emitting units, and the laser wavelengths emitted by the plurality of laser emitting units are the same or different.

[0021] In one embodiment, the loading platform is rotatably and / or horizontally movably disposed on the bracket.

[0022] In one embodiment, the oxidation etching module includes an ozone generator and an atomizer;

[0023] The ozone generator is capable of generating ozone and delivering the ozone to the stage;

[0024] The atomizer is arranged on the ozone generator, and can atomize the etching liquid and spray the atomized etching liquid toward the stage.

[0025] In one of the embodiments, the detection device includes a heating module, and the heating module is disposed on a side of the stage facing the target wafer.

[0026] The above-mentioned detection method and detection device for the metal impurity content of the wafer can use laser irradiation to excite the metal impurities inside the wafer to the surface of the target wafer, so that the metal impurities inside and on the surface of the wafer can be comprehensively collected later, and the metal impurities in the wafer can be accurately detected. The distribution and mass concentration of metal impurities in the wafer can be accurately reflected, which is beneficial to the control of the quality of the wafer in the later stage; it can also shorten the detection time, reduce the detection cost, simplify the sample pre-processing process, and improve the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flow chart of a method for detecting metal impurity content in a wafer provided in one embodiment of the present application.

[0028] Figure 2 This is a simplified structural diagram of a device for detecting metal impurity content in a wafer provided in an embodiment of the present application. Figure 2 The vertical dashed arrow in the figure represents the emission direction of the laser. Figure 2 The horizontal dashed arrow in the figure represents the direction of signal transmission. Figure 2 The curved arrow in FIG. 1 represents the flow direction of the etching solution.

[0029] Figure 3 for Figure 2 A cross-sectional view of a support of a provided detection device.

[0030] The reference numerals in the accompanying drawings are described as follows:

[0031] 10. Detection device; 100. Bracket; 110. Stage; 120. Base; 130. Sliding seat; 140. Support seat; 200. Laser emission module; 300. Oxidation etching module; 310. Ozone generator; 310a. Oxidation etching chamber; 320. Atomizer; 400. Component analysis module; 500. Heating module; 600. Control module. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0034] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0038] With the rapid development of the semiconductor industry, the integration of integrated circuits continues to increase. As the base material of integrated circuits, the quality of wafers is directly related to the performance and reliability of integrated circuits. In the preparation process of wafers, such as in the polishing process, the presence of metal impurities is an issue that cannot be ignored. Metal impurities such as iron, copper, nickel, etc., can seriously affect the performance of semiconductor devices, for example, causing oxide-polysilicon gate structure defects, increased PN junction leakage current, reduced minority carrier lifetime, and changes in threshold voltage, resulting in device performance degradation or even failure. Therefore, the detection of metal impurities in wafers becomes particularly important.

[0039] Currently, the following methods are mainly used to detect the metal impurity content in wafers: first, a VPD device is used to drop VPD solution on the wafer surface to dissolve the metal on the wafer surface. Then, ICP-MS or TXRF is used to analyze the composition of the VPD droplets, and the metal impurity content on the wafer surface is determined based on the analysis results.

[0040] However, this detection method can only detect the metal impurity content on the surface of the wafer, but cannot detect the metal impurities inside the wafer, resulting in low detection accuracy and failure to accurately reflect the distribution and concentration of metal impurities in the wafer body, which is not conducive to the subsequent control of wafer quality.

[0041] In this regard, on the one hand, an embodiment of the present application provides a method for detecting the metal impurity content of a wafer, such as Figure 1 As shown, the detection method includes:

[0042] Step S100, irradiating a laser onto a target wafer to excite metal impurities inside the target wafer to the surface of the target wafer;

[0043] Step S200, oxidizing and etching the surface layer of the target wafer in sequence;

[0044] Step S300: using a chemical vapor decomposition solution to collect metal impurities deposited on the surface of the target wafer, and then detecting the content of metal ions in the chemical vapor decomposition solution.

[0045] Among them, in step S100, irradiating the target wafer with laser light can promote the opening of metal chemical bonds inside the target wafer, so that the metal impurities inside the target wafer diffuse to the surface layer of the target wafer in the form of ions. It should be noted here that the "surface layer" in the full text refers to the outermost structure of the target wafer, which has a certain thickness, which can be several microns.

[0046] During the process of laser irradiation of the target wafer, the target wafer can be rotated and / or moved horizontally. As an example, when the target wafer is rotated at a preset speed, the target wafer is moved horizontally at a preset speed at the same time. Such an arrangement can ensure that the laser beam can be evenly irradiated to the surface of the target wafer. Optionally, the rotation speed of the target wafer is less than or equal to 3000rpm, for example, it can be set to 100rpm, 1000rpm, 2000rpm, 3000rpm, etc. Preferably, the rotation speed of the target wafer is set to 2000rpm to 3000rpm, for example, it can be set to 2000rpm, 2100rpm, 2200rpm, 2300rpm, 2400rpm, 2500rpm, 2600rpm, 2700rpm, 2800rpm, 2900rpm, 3000rpm, etc.

[0047] During the processing of the target wafer, not only light metals (Na, Mg, Al, K, Ca, etc.) will be contaminated, but also heavy metals (Cr, Mn, Fe, Ni, Cu, etc.) will be contaminated. In order to comprehensively detect the content of various metal impurities, lasers of different wavelengths can be used to irradiate the target wafer so that multiple metal impurities can be diffused to the surface of the target wafer. Each metal impurity corresponds to a laser of a specific wavelength.

[0048] Optionally, the wavelength of the laser is 200nm to 1100nm, for example, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, etc. In this way, most of the metal impurities inside the target wafer can be diffused to the surface of the target wafer under the action of the laser, and the metal impurities of the target wafer can be fully detected. Preferably, the wavelength of the laser is 600nm to 1000nm. Lasers of this wavelength can diffuse the metal impurities (such as Ni, Cu, etc.) in the target wafer that have the greatest impact on the quality of the wafer to the surface of the target wafer.

[0049] In this embodiment, the power of the laser is 20mW to 300mW, for example, it can be set to 20mW, 50mW, 100mW, 150mW, 200mW, 250mW, 300mW, etc. By limiting the power of the laser, the diffusion rate of the metal impurities inside the target wafer can be accelerated. Preferably, the power of the laser is 100mW to 200mW, for example, it can be set to 100mW, 110mW, 120mW, 130mW, 140mW, 150mW, 160mW, 170mW, 180mW, 190mW, 200mW, etc.

[0050] In this implementation, the angle between the laser and the surface of the target wafer is 0° to 90°, for example, it can be set to 0°, 10°, 20°, 30°, 40°, 45°, 50°, 60°, 70°, 80°, 90°, etc. By limiting the angle between the laser and the surface of the target wafer, it can be ensured that the laser is irradiated to the surface of the target wafer. Preferably, the angle between the laser and the surface of the target wafer is 45° to 90°.

[0051] In this implementation, the laser irradiation time is less than or equal to 10 minutes, for example, it can be set to 10 minutes, 9 minutes, 8 minutes, 7 minutes, 6 minutes, 5 minutes, 4 minutes, 3 minutes, 2 minutes, 1 minute, 0.5 minutes, etc. By limiting the laser irradiation time, it can be ensured that the metal impurities inside the target wafer can be fully diffused to the surface of the target wafer, thereby improving the detection accuracy, shortening the detection time, and reducing the detection cost.

[0052] In step S200, ozone may be used to oxidize the target wafer. Ozone may oxidize the silicon on the surface of the target wafer to silicon dioxide to form an oxide layer on the outermost side of the surface of the target wafer, while the metal ions on the surface of the target wafer will not be oxidized but deposited below the oxide layer. Optionally, the mass concentration of ozone is greater than 99.5%, for example, it may be set to 99.55%, 99.6%, 99.7%, 99.8%, 99.9%, etc. Ozone of this mass concentration has a strong oxidizing ability and can effectively oxidize the silicon on the surface of the target wafer.

[0053] Of course, in some other embodiments, oxidants such as hydrogen peroxide may also be used to oxidize the silicon in the target wafer.

[0054] Optionally, the oxidation thickness of the surface layer of the target wafer is less than or equal to 10 μm, for example, it can be set to 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, etc. Such a setting is conducive to the subsequent etching of the oxide layer on the outside of the target wafer. It should be noted here that the oxidation thickness of the surface layer of the target wafer refers to the thickness of the oxide layer formed on the surface of the target wafer after being oxidized by ozone.

[0055] In step S200, the etching solution can be atomized, and the target wafer is etched with the atomized etching solution to remove the outermost oxide layer of the target wafer, thereby releasing the metal ions deposited under the oxide layer. Atomizing the etching solution can not only save the amount of etching solution, but also ensure the etching effect.

[0056] Optionally, the etching solution is a hydrofluoric acid solution.

[0057] Before step S200, the detection method further includes step S400, heating the wafer. The heating step can enhance the diffusion of metal impurities inside the wafer, ensure that the metal impurities inside the target wafer can be fully diffused to the surface of the target wafer, and improve the detection accuracy.

[0058] Optionally, the heating temperature of the target wafer is less than or equal to 300° C., for example, it can be set to 300° C., 290° C., 280° C., 270° C., 260° C., 250° C., 240° C., 220° C., 200° C., etc. Such a setting can effectively diffuse the metal impurities inside the wafer without damaging the target wafer.

[0059] In step S300, a VPD device can be used to drop gas-phase decomposition droplets onto the surface of a target wafer, and the gas-phase decomposition droplets are purged so that the gas-phase decomposition droplets roll on the surface of the target wafer; thereafter, an ICP-MS or TXRF scanning tube is used to absorb the VPD droplets on the surface of the target wafer, and a component analysis is performed on the VPD droplets, and the metal impurity content on the wafer surface is determined based on the analysis results.

[0060] It can be seen that the detection method of the metal impurity content of the wafer provided in this embodiment can excite the metal impurities inside the wafer to the surface of the target wafer by adding a laser irradiation step, so that the metal impurities inside and on the surface of the wafer can be fully collected later, and the metal impurities in the wafer can be accurately detected, which can accurately reflect the distribution and concentration of metal impurities in the wafer body, which is conducive to the control of the quality of the wafer in the later stage; and it can also shorten the detection time, reduce the detection cost, simplify the sample pre-processing process, and improve the detection efficiency. In addition, the detection method is suitable for the detection of various wafer sizes and types, and has a wide range of applicability. It is not only suitable for wafer quality control in the semiconductor industry, but also helps to improve the performance and reliability of integrated circuits.

[0061] On the other hand, an embodiment of the present application further provides a device 10 for detecting metal impurity content in a wafer, such as Figure 2 As shown, the detection device 10 includes a support 100, a laser emission module 200, an oxidation etching module 300, a gas phase decomposition module (not shown in the figure) and a component analysis module 400. The support 100 is mainly used to carry the target wafer 20. Figure 2 As shown, the support 100 is provided with a stage 110 for carrying the target wafer 20 .

[0062] The laser emitting module 200 is used to emit laser light to the target wafer 20 to excite the metal impurities inside the target wafer 20 to the surface of the target wafer 20. Irradiating the laser light onto the target wafer 20 can promote the opening of the metal chemical bonds inside the target wafer 20, so that the metal impurities inside the target wafer 20 diffuse to the surface of the target wafer 20 in the form of ions.

[0063] In one embodiment, the laser emitting module 200 includes a plurality of laser emitting units, and the laser wavelengths emitted by the plurality of laser emitting units are the same or different. During the processing of the target wafer 20, not only light metal (Na, Mg, Al, K, Ca, etc.) contamination will be caused, but also heavy metal (Cr, Mn, Fe, Ni, Cu, etc.) contamination will be caused. In order to be able to comprehensively detect the content of various metal impurities, lasers of different wavelengths can be used to irradiate the target wafer 20 so that a variety of metal impurities diffuse to the surface of the target wafer 20. Among them, each metal impurity corresponds to a laser of a specific wavelength.

[0064] In one embodiment, the stage 110 is rotatably and / or horizontally movable on the support 100. As an example, the stage 110 is rotatably and horizontally movable on the support 100, that is, when the target wafer 20 is rotated at a preset speed, the target wafer 20 is horizontally moved at a preset speed. Such a configuration can ensure that the laser beam can be evenly irradiated to the surface of the target wafer 20.

[0065] Alternatively, if Figure 3 As shown, the bracket 100 includes a base 120, a sliding base 130 and a support base 140. The sliding base 130 can slide linearly along the base 120. The support base 140 is rotatably arranged on the sliding base 130 and connected to the stage 110. Optionally, a first motor is arranged on the base 120, and the first motor drives the sliding base 130 to slide linearly on the base 120 through a screw nut assembly. Optionally, a second motor is arranged on the sliding base 130, and the second motor drives the support base 140 to rotate on the sliding base 130 through a transmission gear assembly.

[0066] The oxidation etching module 300 can perform oxidation treatment and etching treatment on the surface layer of the target wafer 20 in sequence. Figure 2 As shown, the oxidation etching module 300 includes an ozone generator 310 and an atomizer 320; the ozone generator 310 can generate ozone and deliver the ozone to the stage 110; the atomizer 320 is disposed on the ozone generator 310, and can atomize the etching liquid and spray the atomized etching liquid toward the stage 110. The ozone can oxidize the silicon on the surface of the target wafer 20 to silicon dioxide, so as to form an oxide layer on the outermost surface of the target wafer 20, while the metal ions on the surface of the target wafer 20 will not be oxidized, but will be deposited under the oxide layer; thereafter, the target wafer 20 is etched with the atomized etching liquid to remove the outermost oxide layer of the target wafer 20, thereby releasing the metal ions deposited under the oxide layer.

[0067] Optionally, the ozone generator 310 includes a housing and an ozone generating body, the ozone generating body is arranged in the housing and has an exhaust port, the housing has an oxidation etching chamber 310a, and the exhaust port of the ozone generating body is communicated with the oxidation etching chamber 310a; the atomizer 320 is placed in the housing and has a mist exhaust port communicated with the oxidation etching chamber 310a. The oxidation etching module 300 of this structure is compact.

[0068] The gas phase decomposition module can drop chemical gas phase decomposition liquid onto the surface of the target wafer 20. In one embodiment, the gas phase decomposition module includes a droplet unit and a purge unit; the droplet unit can drop the gas phase decomposition liquid onto the surface of the target wafer 20; the purge unit can purge the gas phase decomposition liquid droplets so that the gas phase decomposition liquid droplets roll on the surface of the target wafer 20.

[0069] The component analysis module 400 can collect the chemical vapor decomposition liquid containing metal impurities on the surface of the target wafer 20, and perform component analysis on the chemical vapor decomposition liquid containing metal impurities to obtain the content of metal impurities in the chemical vapor decomposition liquid. In one embodiment, the component analysis module 400 includes a scanning tube and an analysis unit; the scanning tube can collect the chemical vapor decomposition liquid containing metal impurities on the surface of the target wafer 20; the analysis unit can perform component analysis on the chemical vapor decomposition liquid containing metal impurities to obtain the content of metal impurities in the chemical vapor decomposition liquid. Optionally, the analysis unit can be an ICP-MS analyzer or a TXRF analyzer.

[0070] It can be seen that the detection device 10 for the metal impurity content of the wafer provided in this embodiment can irradiate the laser onto the wafer 20 through the laser irradiation module, and can excite the metal impurities inside the wafer 20 to the surface of the target wafer 20, so that the metal impurities inside and on the surface of the wafer 20 can be fully collected later, and the metal impurities in the wafer 20 can be accurately detected, and the distribution and concentration of the metal impurities in the wafer body 20 can be accurately reflected, which is conducive to the control of the quality of the wafer 20 in the later stage; and it can also shorten the detection time, reduce the detection cost, simplify the sample pre-processing process, and improve the detection efficiency. In addition, the detection device 10 is suitable for the detection of various sizes and types of wafers 20, and has a wide range of applicability. It is not only suitable for the quality control of wafers 20 in the semiconductor industry, but also helps to improve the performance and reliability of integrated circuits.

[0071] In some embodiments of the present application, Figure 2 As shown, the detection device 10 includes a heating module 500, which is disposed on a side of the stage 110 facing the target wafer 20. The heating module 500 can heat the target wafer 20, which can enhance the diffusion of metal impurities inside the wafer 20, and can ensure that the metal impurities inside the target wafer 20 can be fully diffused to the surface of the target wafer 20, thereby improving the detection accuracy.

[0072] Optionally, the heating module 500 is a heating plate provided with a resistance wire.

[0073] In some embodiments of the present application, Figure 2 As shown, the detection device 10 further includes a control module 600, which is electrically connected to the support 100, the laser emission module 200, the oxidation etching module 300, the gas phase decomposition module and the component analysis module 400 to control the operation of each component. The control module 600 can improve the automation level of the entire device. For example, the horizontal movement speed and the rotation speed of the stage 110 can be correspondingly adjusted by controlling the first motor and the second motor of the support 100; for another example, the on and off, power and irradiation time of each laser emission unit of the laser emission module 200 can be controlled.

[0074] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for detecting metal impurity content in a wafer, characterized in that: include: Irradiating a laser onto a target wafer to excite metal impurities inside the target wafer to a surface layer of the target wafer; performing oxidation treatment and etching treatment on the surface layer of the target wafer in sequence; The metal impurities deposited on the surface of the target wafer are collected by using a chemical vapor decomposition solution, and then the content of the metal impurities in the chemical vapor decomposition solution is detected.

2. The detection method according to claim 1, characterized in that: In the process of irradiating the target wafer with the laser, the detection method further includes: rotating and / or horizontally moving the target wafer.

3. The detection method according to claim 1, characterized in that: The wavelength of the laser is 200nm to 1100nm, and / or the power of the laser is 20mW to 300mW, and / or the angle between the laser and the surface of the target wafer is 0° to 90°, and / or the irradiation time of the laser is less than or equal to 10min.

4. The detection method according to claim 1, characterized in that: Oxidizing the target wafer with ozone, wherein the mass concentration of the ozone is greater than 99.5%; And / or, the oxidation thickness of the target wafer surface layer is less than or equal to 10 μm.

5. The detection method according to any one of claims 1 to 4, characterized in that: Before performing oxidation treatment on the target wafer, the detection method further includes: heating the target wafer, wherein the heating temperature of the target wafer is less than or equal to 300°C.

6. A device for detecting metal impurity content in a wafer, characterized in that: include: A support, provided with a stage for carrying a target wafer; A laser emission module, used for emitting laser to the target wafer, so as to excite metal impurities inside the target wafer to the surface of the target wafer; An oxidation etching module, capable of sequentially performing oxidation treatment and etching treatment on the surface layer of the target wafer; A gas phase decomposition module capable of dropping chemical gas phase decomposition liquid onto the surface of the target wafer; The component analysis module can collect the chemical vapor decomposition liquid containing the metal impurities on the surface of the target wafer, and perform component analysis on the chemical vapor decomposition liquid containing the metal impurities to obtain the content of the metal impurities in the chemical vapor decomposition liquid.

7. The detection device according to claim 6, characterized in that: The laser emitting module includes a plurality of laser emitting units, and the wavelengths of lasers emitted by the plurality of laser emitting units are the same or different.

8. The detection device according to claim 6, characterized in that: The loading platform is rotatably and / or horizontally movable on the bracket.

9. The detection device according to claim 6, characterized in that: The oxidation etching module includes an ozone generator and an atomizer; The ozone generator is capable of generating ozone and delivering the ozone to the stage; The atomizer is arranged on the ozone generator, and can atomize the etching liquid and spray the atomized etching liquid toward the stage.

10. The detection device according to any one of claims 6 to 9, characterized in that: The detection device comprises a heating module, and the heating module is arranged on a side of the stage facing the target wafer.

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