Electron particle beam imaging device and wafer defect detection method

Abstract

The invention discloses an electron-carrying particle beam imaging device and a wafer defect detection method, the electron-carrying particle beam imaging device comprises an emission unit, a first convergence unit, a second convergence unit and two deflection units, the emission unit is used for emitting a particle beam; the first convergence unit is arranged at the downstream of the emission unit, and the first convergence unit is used for converging the particle beam to form a converged beam; the second convergence unit is arranged at the downstream of the first convergence unit and is used for forming the concentrated beam into a fine beam spot; the two deflection units are sequentially arranged at the downstream of the first convergence unit, each deflection unit is used for changing the moving direction of particles, and each deflection unit comprises a first deflector responding to the first excitation source and a second deflector responding to the second excitation source; wherein the opening states of the first excitation source and the second excitation source are opposite, so that a concentrated beam emitted by the first convergence unit is subjected to the action of the two first deflectors or the two second deflectors to obtain a scanning beam inclined relative to the to-be-detected surface of the sample.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor processing technology, and in particular relates to an electron particle beam imaging device and a wafer defect detection method. Background Art

[0002] As the basic carrier of chips, the quality of wafers directly affects the quality and reliability of subsequent products. In related technologies, wafer defect detection equipment scans the surface of wafers through an electron microscope and obtains defect-related information based on scanning imaging.

[0003] However, the electron microscopes currently in use cannot meet the measurement requirements of the wafer edge. On the one hand, this prolongs the defect analysis time and delays the problem solving cycle; on the other hand, it is not conducive to improving the defect detection accuracy. Summary of the invention

[0004] The embodiment of the present application provides an electron particle beam imaging device and a wafer defect detection method. The electron particle beam imaging device can realize two-stage deflection of the particle beam through two deflection units, thereby scanning the edge position of the wafer. The electron particle beam imaging device can switch the first excitation source and the second excitation source to obtain two images, and combine them to complete the wafer defect determination, thereby improving the accuracy of wafer defect detection.

[0005] In a first aspect, an embodiment of the present application provides an imaging device with an electron particle beam, comprising an emitting unit, a first converging unit, a second converging unit, and two deflection units, wherein the emitting unit is used to emit a particle beam; the first converging unit is arranged downstream of the emitting unit, and the first converging unit is used to converge the particle beam to form a converged beam; the second converging unit is arranged downstream of the first converging unit, and is used to form the converged beam into a fine beam spot; the two deflection units are sequentially arranged downstream of the first converging unit, each deflection unit is used to change the moving direction of the particles, and each deflection unit comprises a first deflector responsive to a first excitation source and a second deflector responsive to a second excitation source;

[0006] The first excitation source and the second excitation source are turned on in opposite states, so that the focused beam emitted by the first converging unit passes through the two first deflectors or the two second deflectors to obtain a scanning beam inclined relative to the surface of the sample to be tested.

[0007] In some of the embodiments, the first excitation source is a voltage excitation source, the second excitation source is a current excitation source, and in each deflection unit, the first deflector is an electrostatic deflector, and the second deflector is a magnetoelectric deflector.

[0008] In some of the embodiments, in each deflection unit, along the radial direction of the particle beam, the first deflector is arranged on the inner side of the second deflector.

[0009] In some of the embodiments, in each deflection unit, the first deflector includes at least one pair of pole plates parallel to each other, and the second deflector includes two coils, which are connected to one pair of pole plates, and the coils are arranged on opposite sides of the pole plates.

[0010] In some of the embodiments, in each deflection unit, a field of view angle corresponding to a first deflector is smaller than a field of view angle corresponding to a second deflector.

[0011] In some of the embodiments, in the two deflection units, a maximum field of view angle corresponding to the first deflector is smaller than a minimum field of view angle corresponding to the second deflector.

[0012] In some of the embodiments, along the radial direction of the particle beam, the two deflection units are both disposed inside the second converging unit, so that the scanning beam is deflected while being converged.

[0013] In some of the embodiments, the first converging unit includes at least one condensing lens, and the condensing lens is an electromagnetic lens or an electrostatic lens;

[0014] The second focusing unit includes at least an objective lens.

[0015] In a second aspect, an embodiment of the present application provides a wafer defect detection method, which is implemented based on the electron particle beam imaging device provided in any of the above embodiments. The wafer defect detection method includes:

[0016] Turning on a first excitation source to obtain a first detection image of a first side of a wafer to be tested;

[0017] Turn off the first excitation source, turn on the second excitation source, and obtain a second detection image of the first side of the wafer to be tested;

[0018] The defect type is determined based on the first inspection image and the second inspection image.

[0019] In some of the embodiments, the wafer defect detection method further includes: acquiring a second detection image of the first side of the wafer to be detected based on the first detection image; and / or,

[0020] A second detection image of the first side of the wafer to be tested is acquired based on at least one of a radius and an angle of the wafer to be tested.

[0021] The electron-bearing particle beam imaging device of the embodiment of the present application gathers the particles emitted from the emission unit through the first converging unit to form a particle beam, realizes two-stage deflection of the particle beam through two deflection units arranged downstream of the first converging unit, and at the same time, the second converging unit focuses the particle beam to form a fine beam spot, and the deflected scanning particle beam can move relative to the wafer surface to realize defect detection on the wafer surface. The electron-bearing particle beam imaging device can adjust the deflection amplitude of the scanning particle beam through two first deflectors or two second deflectors, thereby obtaining two images with different fields of view, which can provide more image basis for wafer surface defect determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0023] Figure 1 A schematic diagram of a system with an electron particle beam imaging device according to some embodiments of the present application;

[0024] Figure 2 A schematic diagram of a process flow of a wafer defect detection method according to some embodiments of the present application;

[0025] Figure 3 A schematic diagram of a process flow of a wafer defect detection method according to some embodiments of the present application;

[0026] Figure 4 Schematic diagram of sub-processes of wafer defect detection methods according to some embodiments of the present application.

[0027] The reference numerals in the specific implementation manner are as follows:

[0028] 100, particle beam; 110, electron source; 121, first electrode; 122, second electrode;

[0029] 200, a first converging unit; 210, a condenser lens;

[0030] 300, a second converging unit;

[0031] 400, deflection unit; 410, first deflector; 420, second deflector. DETAILED DESCRIPTION

[0032] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0034] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0035] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0036] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0037] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0038] In the description of the embodiments of the present application, the technical 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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0039] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral 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, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0040] As the basic carrier of chips, the quality of wafers directly affects the quality and reliability of subsequent products. In related technologies, wafer defect detection equipment scans the surface of wafers through an electron microscope and obtains defect-related information based on scanning imaging.

[0041] However, although the currently used scanning electron microscope (SEM) has high resolution, it cannot achieve imaging of the top bevel and bevel areas while scanning the wafer surface. Therefore, when part of the defect is located in the edge area of ​​the wafer, the electron microscope cannot fully observe the defect and it is difficult to meet the measurement requirements. This not only prolongs the defect analysis time and delays the problem solving cycle, but also easily leads to misjudgment and other situations.

[0042] In addition, when the relevant electron particle beam imaging device scans and images the wafer surface, due to the small field of view of the image, it is difficult to clearly observe whether there are pits or protrusions at the defect in the same image, which is not conducive to improving the accuracy of defect detection.

[0043] In order to solve the problems in the prior art, the embodiments of the present application provide an electron particle beam imaging device and a wafer defect detection method. The electron particle beam imaging device provided in the embodiments of the present application is first introduced below.

[0044] See also Figure 1In a first aspect, an embodiment of the present application provides an electron particle beam imaging device for acquiring an image of a surface to be tested of a wafer. The electron particle beam imaging device includes an emitting unit, a first converging unit 200 disposed downstream of the emitting unit, a second converging unit 300 disposed downstream of the first converging unit 200, and two deflection units 400. The emitting unit is used to emit a particle beam 100, the first converging unit 200 is used to converge the particle beam 100 to form a converged beam, the second converging unit 300 is used to form a fine beam spot from the converged beam, and each deflection unit 400 is used to change the direction of particle movement. Each deflection unit 400 includes a first deflector 410 and a second deflector 420, the first deflector 410 responds to a first excitation source, the second deflector 420 responds to a second excitation source, and the first excitation source and the second excitation source have opposite turn-on states.

[0045] The particle beam 100 emitted by the emission unit undergoes a first convergence through the first converging unit 200 to form a concentrated beam, and the concentrated beam undergoes a second convergence through the second converging unit 300 to form a fine beam spot. The fine beam spot changes its moving direction under the action of the two deflection units 400, and finally forms a scanning beam inclined relative to the surface of the sample to be tested.

[0046] Thus, by controlling the deflection unit 400, the inclination angle of the scanning beam relative to the surface to be tested of the sample can be adjusted, and then the scanning beam can be moved relative to the sample to traverse the surface to be tested, and an image for defect detection can be obtained. The electron particle beam imaging device can start the two first deflectors 410 or the two second deflectors 420 by switching the first excitation source or the second excitation source, and adjust the deflection amplitude of the particles to adjust the emission angle of the scanning beam, thereby obtaining two images with different field of view ranges. The two images can be used to observe the microscopic morphology and macroscopic morphology of the defects respectively, providing more image basis for wafer defect detection and judgment, and helping to improve the accuracy and efficiency of wafer defect detection.

[0047] It should be noted that the microscopic morphology and macroscopic morphology referred to in this application are different from the microscopic and macroscopic in a broad sense, but refer to the relative microscopic in which defect details can be observed, and the relative macroscopic in which most of the defect boundary lines or the entire defect boundary lines can be observed.

[0048] According to some embodiments of the present application, the first excitation source is a voltage excitation source, and the first deflector is an electrostatic deflector.

[0049] Optionally, the first deflector 410 is configured as a plate-type electrostatic deflector.

[0050] Optionally, the first deflector 410 is configured as a column-type electrostatic deflector. Exemplarily, the first deflector 410 is an octupole electrostatic deflector.

[0051] Thus, the first deflector 410 generates an electrostatic field under voltage excitation, and the particles are deflected under the action of the electrostatic force after entering, thereby achieving the deflection of the exit direction of the fine beam spot. The electrostatic force on the particles entering the electrostatic field can be changed by adjusting the magnitude of the excitation voltage, thereby achieving the adjustment of the exit direction of the fine beam spot.

[0052] It can be understood that, in the two deflection units 400, the electric field strength of the first deflector 410 close to the sample is greater than the electric field strength of the first deflector 410 far from the sample, so that the focused beam can be further deflected under the action of electrostatic force when entering the first deflector 410 close to the sample. The deflection angle of the scanning beam is expanded through two-stage deflection. Combined with the high-speed scanning characteristics of electrostatic deflection, the efficiency of the electron particle beam imaging device in obtaining the image of the sample surface to be tested is improved.

[0053] According to some embodiments of the present application, the second excitation source is a current excitation source, and the second deflector 420 is a magnetoelectric deflector.

[0054] Thus, the second deflector 420 generates a magnetic field under the excitation of the current, and the particles are deflected under the action of the Lorentz force after entering, so as to achieve the deflection of the exit direction of the fine beam spot. The Lorentz force on the particles entering the magnetic field can be changed by adjusting the magnitude of the excitation current, thereby adjusting the exit direction of the fine beam spot.

[0055] It can be understood that, in the two deflection units 400, the magnetic field strength of the second deflector 420 close to the sample is greater than the magnetic field strength of the second deflector 420 far from the sample, so that the focused beam can be further deflected under the action of the Lorentz force when entering the second deflector 420 close to the sample, and the deflection angle of the scanning beam is expanded through two-stage deflection, thereby realizing scanning imaging of the edge position of the wafer surface to be measured and realizing measurement of the edge position of the wafer.

[0056] Thus, the electron-bearing particle beam imaging device can realize two-stage electrostatic deflection of the particle beam 100 through two electrostatic deflectors, or realize two-stage magnetic deflection of the particle beam 100 through two magnetic deflectors, so as to obtain two types of images with different fields of view to combine and determine the type of wafer defects. At the same time, the electron-bearing particle beam imaging device can also switch the first excitation source and the second excitation source to adjust the deflection unit 400 as needed, use the magnetic deflector to obtain an image with a smaller difference, or use the electrostatic deflector to scan the wafer at high speed to obtain the detection image faster, and flexibly adapt to different detection needs.

[0057] According to certain embodiments of the present application, in the same deflection unit 400 , the first deflector 410 and the second deflector 420 are arranged sequentially along the emission direction of the particle beam 100 , or, along the radial direction of the particle beam 100 , the first deflector 410 is arranged on the inner side or the outer side of the second deflector 420 .

[0058] Further, in the two deflection units 400 , the positional relationship between the first deflector 410 and the second deflector 420 is the same, or the positional relationship between the first deflector 410 and the second deflector 420 is different.

[0059] Therefore, the internal structure of the deflection unit 400 can be flexibly adjusted according to different production requirements such as imaging accuracy or equipment space.

[0060] For example, see Figure 1 In each deflection unit 400, along the radial direction of the particle beam 100, the first deflector 410 is arranged inside the second deflector 420. On the one hand, the emission path of the particle beam 100 is shortened, and the reduction of the beam spot quality caused by the excessively long path of the particle beam 100 is alleviated; on the other hand, the integration of the first deflector 410 and the second deflector 420 in the emission direction of the particle beam 100 helps to reduce the volume of the electron particle beam imaging device and realize the miniaturization of the detection equipment.

[0061] According to some embodiments of the present application, in each deflection unit 400, the first deflector 410 includes at least one pair of parallel pole plates, and the second deflector 420 includes two coils, which are arranged corresponding to one pair of pole plates. Exemplarily, the coil of the second deflector 420 is arranged on the side away from the pole plates, that is, along the radial direction of the particle beam 100, the coil of the second deflector 420 is arranged outside the pole plates.

[0062] Further optionally, in some embodiments, the first deflector 410 is directly connected to the second deflector 420 to achieve relative fixation of the first deflector 410 and the second deflector 420 .

[0063] Further optionally, in some other embodiments, the deflection unit 400 further includes a connecting member, and the first deflector 410 and the second deflector 420 are both mounted on the connecting member to achieve relative fixation of the first deflector 410 and the second deflector 420 .

[0064] According to certain embodiments of the present application, in each deflection unit 400 , a field of view angle corresponding to the first deflector 410 is smaller than a field of view angle corresponding to the second deflector 420 .

[0065] Therefore, the electron particle beam imaging device can obtain two images with different fields of view by turning on the first excitation source or the second excitation source, and then obtain more defect morphology information through image comparison, providing more basis for defect judgment, and improving the efficiency and accuracy of defect detection operations.

[0066] Furthermore, in the two deflection units 400 , the maximum field of view angle corresponding to the first deflector 410 is smaller than the minimum field of view angle corresponding to the second deflector 420 .

[0067] As a result, the image obtained by turning on the first excitation source is significantly different from the image obtained by turning on the second excitation source, thereby achieving the acquisition of macroscopic and microscopic morphological information of the defect, and further improving the accuracy of the defect detection operation.

[0068] According to some embodiments of the present application, the deflection unit 400 away from the sample is disposed inside the second focusing unit 300 along the radial direction of the particle beam 100 .

[0069] Optionally, along the radial direction of the particle beam 100 , a deflection unit 400 close to the sample is also disposed in the second converging unit 300 , so that the focused beam can complete two-stage deflection inside the second converging unit 300 , thereby improving the accuracy of the scanning beam.

[0070] As a result, the integration level of the electron particle beam imaging device is improved while the emission path of the particle beam 100 is shortened, thereby alleviating the degradation of the beam spot quality caused by the excessively long path of the particle beam 100; in addition, the electrostatic field or magnetic field of the deflection unit 400 can be superimposed on the field distribution formed by the second converging unit 300, thereby reducing the deflection chromatic aberration and compensating for the loss of imaging accuracy caused by the two-stage deflection setting.

[0071] According to some embodiments of the present application, the emission unit includes an electron source 110 to excite an electron beam, and the electron particle beam imaging device implements wafer defect detection through electron beam imaging.

[0072] Optionally, the emission unit further includes a first electrode 121, which is disposed downstream of the electron source 110, and a voltage V1 of the first electrode 121 is less than 0. The first electrode 121 is used to suppress stray electrons in the electron beam to adjust the current size, thereby adjusting the energy size of the electron beam.

[0073] Further optionally, the emission unit also includes a second electrode 122, which is arranged downstream of the electron source 110, and the voltage V2 of the second electrode 122 is greater than or equal to 0. The second electrode 122 is used to guide the movement path of the electron beam and reduce energy loss. The electron beam can be shaped by adjusting the size of V2.

[0074] Further optionally, the electron source 110, the first electrode 121, and the second electrode 122 are coaxially arranged in sequence, and the high point tail difference between the first electrode 121 and the second electrode 122 can accelerate the electrons, thereby adjusting the energy of the electron beam emitted by the emission unit so that it is sufficient to be recognized by the detector in subsequent detection.

[0075] It can be understood that in some embodiments, the emission unit includes an ion source, the particle beam 100 is an ion beam, the ion beam can be deflected in response to an electrostatic deflector or a magnetic deflector, and a structure for adjusting the quality of the ion beam is correspondingly provided downstream of the ion source.

[0076] According to some embodiments of the present application, the first focusing unit 200 includes at least one focusing lens 210 .

[0077] Optionally, the first converging unit 200 is provided with two condensing mirrors 210 , and along the electron beam emission direction, the two condensing mirrors 210 are both located upstream of the second converging unit 300 and any deflection unit 400 .

[0078] Optionally, the condenser 210 is configured as at least one of an electromagnetic lens or an electrostatic lens to achieve a focusing effect on the electron beam. Exemplarily, the two condensers 210 include an electromagnetic lens and a classical lens.

[0079] Therefore, by adjusting the field distribution of the condensing mirror 210, the focusing effect of the first converging unit 200 on the electron beam is adjusted, thereby achieving beam diameter adjustment or energy adjustment of the concentrated beam.

[0080] According to some embodiments of the present application, the second focusing unit 300 includes at least an objective lens.

[0081] Optionally, the second converging unit 300 is configured as a separate objective lens, and along the particle beam emission direction, the two deflection units are both located inside the objective lens.

[0082] Optionally, the second converging unit 300 further includes at least one lens, which is an electromagnetic lens or an electrostatic lens, to enhance the focusing effect of the second converging unit on the particle beam. Specifically, along the emission direction of the particle beam, the lens is disposed upstream of the objective lens.

[0083] See also Figure 2 In a second aspect, an embodiment of the present application further provides a wafer defect detection method, which is implemented based on the electron particle beam imaging device provided in any of the above embodiments, and the wafer defect detection method includes:

[0084] S100, turning on a first excitation source to obtain a first detection image of a first side of a wafer to be tested;

[0085] S200, turning off the first excitation source, turning on the second excitation source, and acquiring a second detection image of the first side of the wafer to be tested;

[0086] S300 , determining the defect type based on the first detection image and the second detection image.

[0087] Therefore, the first detection image and the second detection image can complement each other and be combined to realize defect determination of the wafer surface to be tested, thereby improving the accuracy of wafer defect detection.

[0088] It should be noted that the wafer to be tested may be a bare wafer or a processed wafer, such as a patterned wafer. When the wafer to be tested is a processed wafer, the first side is a processed side of the processed wafer.

[0089] According to some embodiments of the present application, the wafer defect detection method further includes:

[0090] S010. Calibrate the wafer to be tested based on at least one of the notch mark and the edge mark of the wafer to be tested to obtain the center position of the wafer to be tested.

[0091] Exemplarily, the wafer to be tested is calibrated based on the notch mark and the edge mark of the wafer to be tested to improve the positioning accuracy.

[0092] Thus, the spatial position of the wafer to be tested is obtained, and the electron particle beam imaging device moves according to the center position of the wafer to be tested, so that the fine beam spot is projected toward the center of the wafer to be tested when the deflection unit 400 is not turned on.

[0093] According to some embodiments of the present application, step S200 specifically includes:

[0094] S210A, acquiring a second detection image of the first side of the wafer to be tested based on the first detection image;

[0095] S210B, acquiring a second detection image of the first side of the wafer to be tested based on at least one of the radius and the angle of the wafer to be tested.

[0096] Specifically, the above step S210A and step S210B can be performed separately or together. When step S210A and step S210B are performed together, the execution order between the two steps is not limited. For example, please refer to Figure 3 When steps S210A and S210B are executed together, the latter step can further obtain a second detection sub-image in the second detection image obtained by the former step, and determine the defect type by combining the second detection sub-image with the first detection image.

[0097] Therefore, the target position and the deflection angle of the scanning beam are determined through the first detection image / the radius of the wafer to be tested / the angle of the wafer to be tested, and the second detection image is obtained, thereby improving the efficiency of the wafer defect detection operation.

[0098] See also Figure 4 According to some embodiments of the present application, step S300 includes:

[0099] S310, identifying a first detection image and obtaining first defect classification information;

[0100] S320: Acquire a standard image set based on the first defect classification information, compare the second inspection image with the standard image set, and acquire second defect classification information.

[0101] Thus, defects are identified through the first detection image to achieve pre-classification. For defects that are difficult to determine based on the first detection image, the possible defects can be quickly identified, thus shortening the problem solving cycle.

[0102] Further, according to some embodiments of the present application, step S300 also includes:

[0103] S330: When the second defect classification information contains two or more defects, collect elemental components at the defect to determine the defect type.

[0104] Optionally, the elemental composition of the defect is determined by energy dispersive X-ray spectroscopy.

[0105] Therefore, defects that are still difficult to determine by combining the first detection image with the second detection image can be further eliminated by means of elemental composition analysis to determine the defect type.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An imaging device with an electron particle beam, characterized in that: include: A launching unit, used for launching a particle beam; A first converging unit is disposed downstream of the emitting unit, and the first converging unit is used to converge the particle beam to form a converged beam; A second converging unit, disposed downstream of the first converging unit, for forming the focused beam into a fine beam spot; Two deflection units are sequentially arranged downstream of the first converging unit, each of the deflection units is used to change the moving direction of the particles, and each of the deflection units includes a first deflector responsive to a first excitation source and a second deflector responsive to a second excitation source; The first excitation source and the second excitation source are turned on in opposite states, so that the focused beam emitted by the first converging unit passes through the two first deflectors or the two second deflectors to obtain a scanning beam inclined relative to the surface of the sample to be tested.

2. The electron particle beam imaging device according to claim 1, characterized in that: The first excitation source is a voltage excitation source, the second excitation source is a current excitation source, and in each of the deflection units, the first deflector is an electrostatic deflector, and the second deflector is a magnetoelectric deflector.

3. The electron particle beam imaging device according to claim 2, characterized in that: In each of the deflection units, along the radial direction of the particle beam, the first deflector is arranged on the inner side of the second deflector.

4. The electron particle beam imaging device according to claim 3, characterized in that: In each of the deflection units, the first deflector includes at least one pair of pole plates parallel to each other, and the second deflector includes two coils, the two coils are connected to one pair of pole plates, and the coils are arranged on the opposite sides of the pole plates.

5. The electron particle beam imaging device according to claim 2, characterized in that: In each of the deflection units, a field of view angle corresponding to the first deflector is smaller than a field of view angle corresponding to the second deflector.

6. The electron particle beam imaging device according to claim 5, characterized in that: In the two deflection units, the maximum field of view angle corresponding to the first deflector is smaller than the minimum field of view angle corresponding to the second deflector.

7. The electron particle beam imaging device according to claim 1, characterized in that: Along the radial direction of the particle beam, the two deflection units are both arranged inside the second converging unit, so that the scanning beam is deflected while being converged.

8. The electron particle beam imaging device according to claim 1, characterized in that: The first converging unit comprises at least one condenser, and the condenser is an electromagnetic lens or an electrostatic lens; The second focusing unit includes at least an objective lens.

9. A wafer defect detection method, implemented based on the electron particle beam imaging device according to any one of claims 1 to 8, characterized in that: include: Turning on a first excitation source to obtain a first detection image of a first side of a wafer to be tested; Turn off the first excitation source, turn on the second excitation source, and obtain a second detection image of the first side of the wafer to be tested; The defect type is determined based on the first inspection image and the second inspection image.

10. The wafer defect detection method according to claim 9, characterized in that: Also includes: Acquire a second detection image of the first side of the wafer to be tested based on the first detection image; and / or, A second detection image of the first side of the wafer to be tested is acquired based on at least one of a radius and an angle of the wafer to be tested.

Images