Electronic detection device, electronic signal detection method and electron microscope

Abstract

The invention discloses an electronic detection device, an electronic signal detection method and an electron microscope. The electronic detection device comprises a first centering assembly, a detector assembly, a second centering assembly, an objective lens and a sample table used for placing a test sample. The first centering assembly is used for controlling the electron beam to deflect, so that the deflected electron beam deviates from the lens cone axis of the electron microscope by a first distance; the second centering assembly is used for controlling the deflected electron beam to deflect again, so that the distance between the electron beam and the axis of the lens barrel is smaller than a preset distance; the objective lens is used for converging the electron beams and acting on the test sample to generate return electronic signals, and the energy of the return electronic signals is smaller than that of the electron beams; the second centering assembly is used for controlling the return electronic signal to deflect, so that the return electronic signal deviates from the lens barrel axis by a second distance; the detector assembly is used for receiving the deflected return electronic signal. According to the embodiment of the invention, the collection of the returned electronic signal is realized, and the reduction of the quality of the electron beam is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of electron microscopes, and in particular relates to an electron detection device, an electron signal detection method and an electron microscope. Background Art

[0002] In recent years, electron microscopes have been widely used in the semiconductor industry. The working principle of electron microscopes is to use a charged particle beam to bombard the surface of the object being tested, and use detectors to detect the electron signals generated in the bombarded area to obtain various physical and chemical information of the test sample itself, such as morphology, composition, characteristic distribution, etc.

[0003] Detectors can be divided into on-axis detectors and off-axis detectors according to their placement. In the off-axis detection method, a high-voltage electric field is applied to the off-axis detector. The electronic signal generated by the test sample is collected by the detector under the action of the high-voltage electric field. However, the high-voltage electric field will also affect the path of the electron beam moving to the test sample, thereby reducing the quality of the main electron beam.

[0004] In addition, the quality of the main electron beam also determines the imaging quality of the electron microscope. A reduction in the quality of the main electron beam means a reduction in the imaging quality of the electron microscope. Summary of the invention

[0005] The embodiments of the present application provide a detection device, an electronic signal detection method and an electron microscope, which can avoid applying a high voltage electric field to an off-axis detector, thereby solving the problem of reduced main electron beam quality and imaging quality due to application of a high voltage electric field to the off-axis detector.

[0006] On the one hand, an embodiment of the present application provides an electron detection device, which is applied to an electron microscope, and the electron detection device includes: a first centering component, a detector component, a second centering component, an objective lens, and a sample stage for placing a test sample;

[0007] The first centering assembly is used to control the deflection of the electron beam so that the deflected electron beam deviates from the axis of the electron microscope barrel by a first distance;

[0008] The second centering component is used to control the deflected electron beam to deflect again, so that the distance between the re-deflected electron beam and the axis of the lens barrel is less than a preset distance;

[0009] The objective lens is used to converge the electron beam after being deflected by the second centering component, and make the converged electron beam act on the test sample, so that the test sample generates a return electron signal under the action of the electron beam, and the energy of the return electron signal is less than the energy of the electron beam;

[0010] The second centering assembly is also used to control the deflection of the returned electronic signal so that the deflected returned electronic signal deviates from the axis of the lens barrel by a second distance;

[0011] The detector assembly is offset from the axis of the lens barrel to avoid the electron beam passing through the first centering assembly, and the detector assembly is used to receive the deflected return electron signal.

[0012] In some embodiments, the first centering assembly, the detector assembly, the second centering assembly, the objective lens and the sample stage are sequentially arranged along the axis of the lens barrel; the first centering assembly includes a first centering component and a second centering component sequentially arranged along the axis of the lens barrel;

[0013] The first centering component is used to control the electron beam to deflect by a first preset angle in a direction away from the axis of the lens barrel;

[0014] The second centering component is used to control the electron beam deflected by the first preset angle to be deflected again toward the direction close to the axis of the lens barrel, so that the re-deflected electron beam deviates from the lens barrel axis of the electron microscope by a first distance.

[0015] In some embodiments, the second centering assembly includes a third centering component and a fourth centering component sequentially disposed along the axis direction of the lens barrel;

[0016] The third centering component is used to control the electron beam to deflect toward a second preset angle in a direction close to the axis of the lens barrel;

[0017] The fourth centering component is used to control the electron beam deflected by the second preset angle to be deflected again in a direction away from the axis of the lens barrel, so that the distance between the electron beam after the deflection is less than the preset distance from the axis of the lens barrel.

[0018] In some embodiments, any of the first centering component, the second centering component, the third centering component, or the fourth centering component includes:

[0019] A first conductive electrode plate and a second conductive electrode plate.

[0020] In some embodiments, any of the first centering component, the second centering component, the third centering component, or the fourth centering component includes a conductive coil.

[0021] In some embodiments, the detector assembly includes at least one detector, the detector including a receiving surface for receiving the return electronic signal.

[0022] In some embodiments, the receiving surface includes a plurality of sub-receiving surfaces arranged in sequence along the radial direction of the lens barrel, and each sub-receiving surface is used to receive a return electronic signal of corresponding energy.

[0023] On the other hand, an embodiment of the present application provides an electronic signal detection method, which is applied to the electronic detection device in the above embodiment. The electronic signal detection method includes:

[0024] Applying a first electrical signal to the first centering component, and controlling the electron beam deflection through the first centering component after the first electrical signal is applied, so that the deflected electron beam deviates from the axis of the electron microscope barrel by a first distance;

[0025] Applying a second electrical signal to the second centering component, and controlling the deflected electron beam to deflect again through the second centering component after the second electrical signal is applied, so that the distance between the electron beam after the deflection is less than a preset distance from the axis of the lens barrel;

[0026] The electron beam deflected by the second centering component after the second electrical signal is applied is converged by an objective lens, and the converged electron beam is applied to a test sample placed on a sample stage, so that the test sample generates a return electron signal, and the energy of the return electron signal is less than the energy of the electron beam;

[0027] Controlling the deflection of the return electronic signal by the second centering assembly after applying the second electrical signal, so that the deflected return electronic signal deviates from the axis of the lens barrel by a second distance;

[0028] The deflected return electron signal is received by the detector assembly.

[0029] In some embodiments, the detector assembly includes at least one detector, the detector includes a receiving surface, and the receiving surface includes a plurality of sub-receiving surfaces sequentially arranged along the radial direction of the lens barrel;

[0030] The deflected return electronic signal is received by the detector assembly, including:

[0031] Each sub-receiving surface of the detector in the detector assembly receives a return electron signal of corresponding energy.

[0032] On the other hand, an embodiment of the present application provides an electron microscope, comprising the electron detection device in the above-mentioned embodiment.

[0033] The electronic detection device of the embodiment of the present application controls the deflection of the electron beam through the first centering component, so that the deflected electron beam deviates from the first distance of the lens barrel axis of the electron microscope; controls the deflected electron beam to deflect again through the second centering component, so that the distance between the electron beam deflected again and the lens barrel axis is less than the preset distance; converges the electron beam deflected by the second centering component through the objective lens, and makes the converged electron beam act on the test sample, so that the test sample generates a return electron signal under the action of the electron beam, and the energy of the return electron signal is less than the energy of the electron beam; controls the deflection of the return electron signal through the second centering component, so that the return electron signal after deflection deviates from the lens barrel axis by the second distance, and the detector component deviates from the lens barrel axis, which is used to avoid the electron beam deflected by the first centering component, and receives the return electron signal after deflection. It can be seen from this that in the embodiment of the present application, the deflection of the electron beam in different directions can be achieved by the first centering component and the second centering component on the path of the electron beam moving to the test sample, thereby enabling the electron beam to act on the test sample according to the emission direction of the electron beam, so that the return electron signal detected by the detector is a valid signal. The return electron signal can be deflected by the second centering component on its moving path. Since the energy of the return electron signal is less than the energy of the electron beam, the deflection angles of the return electron signal and the electron beam in the second centering component are different. The smaller the energy of the electron signal, the larger the deflection angle. This allows the detector to avoid the electron beam and detect the return electron signal. The return electron signal can be detected without applying any voltage to the detector, thereby avoiding the influence of the high-voltage electric field on the moving path of the electron beam and improving the quality of the electron beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 is a schematic diagram of the structure of an exemplary electron microscope;

[0036] Figure 2 A schematic diagram of the structure of an electronic detection device provided in an embodiment of the present application;

[0037] Figure 3 A schematic structural diagram of a first centering component provided in an embodiment of the present application;

[0038] Figure 4 A schematic diagram of the structure of a second centering component provided in an embodiment of the present application;

[0039] Figure 5A schematic diagram of the structure of a detector provided in an embodiment of the present application;

[0040] Figure 6 A schematic diagram of a flow chart of an electronic signal detection method provided in an embodiment of the present application;

[0041] Figure 7 A schematic diagram of the structure of an electron microscope provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0044] In recent years, electron microscopes have been widely used in the semiconductor industry. The electron signals generated by the bombarded area are detected by the detector to obtain various physical and chemical information of the test sample itself, such as morphology, composition, characteristic distribution, etc. Figure 1 is an exemplary electron microscope, such as Figure 1As shown, the electron microscope 100 includes an electron beam emission source 101, a detector 102, an objective lens 103 and a sample stage 104. When the electron microscope 100 is working, a high voltage is applied to the detector 102. After the high voltage is applied to the detector 102, the electron beam emission source 101 emits an electron beam 101a, so that the electron beam 101a acts on a test sample placed on the sample stage along its emission direction and forms a beam spot on the test sample. Under the action of the electron beam 101a, the test sample generates a return electron signal 101b, and the return electron signal 101b is detected by the detector under the action of the high voltage electric field.

[0045] When using the electron microscope, the applicant found that although the high voltage applied to the detector can enable the detector to detect the return electron signal, it will also affect the emitted electron beam, reducing the quality of the electron beam, and further reducing the beam spot quality and imaging quality.

[0046] In order to solve at least one problem in the prior art, an embodiment of the present application provides an electron detection device. The electron detection device provided by the embodiment of the present application can be applied to an electron microscope.

[0047] Figure 2 A schematic diagram of the structure of an electronic detection device provided in an embodiment of the present application.

[0048] See also Figure 2 An electronic detection device 10 provided in an embodiment of the present application may include: a first centering component 11, a detector component 12, a second centering component 13, an objective lens 14 and a sample stage 15 for placing a test sample, wherein the first centering component 11, the detector component 12, the second centering component 13, the objective lens 14 and the sample stage 15 are arranged in sequence along the axial direction of the lens barrel.

[0049] The first centering assembly 11 can be used to control the deflection of the electron beam so that the deflected electron beam deviates from the axis m of the electron microscope by a first distance d. 1 .

[0050] The second centering component 13 can be used to control the deflected electron beam to be deflected again, so that the distance between the re-deflected electron beam and the axis m of the lens barrel is less than a preset distance.

[0051] The objective lens 14 can be used to converge the electron beam after being deflected by the second centering component 13, and make the converged electron beam act on the test sample, so that the test sample generates a return electron signal under the action of the electron beam, and the energy of the return electron signal is less than the energy of the electron beam.

[0052] The second centering component 13 can also be used to control the deflection of the returned electronic signal so that the deflected returned electronic signal deviates from the axis m of the lens barrel by a second distance d 2An electrical signal is applied to the second centering component 13, and under the effect of the electrical signal, the moving direction of the returning electronic signal is deflected.

[0053] The detector assembly 14 is offset from the lens barrel axis m to avoid the electron beam passing through the first centering assembly 11 . The detector assembly 14 can be used to receive the deflected return electron signal.

[0054] Specifically, the first centering component 11 can be located in the lens barrel of the electron microscope. For example, the first centering component 11 can be fixedly arranged on the side wall of the lens barrel of the electron microscope. The first centering components 11 are symmetrically distributed along the lens barrel axis m. An electrical signal is applied to the first centering component 11. After the electrical signal is applied, the first centering component 11 can control the electron beam to deflect in a direction away from the lens barrel axis m. The direction of movement of the electron beam after deflection is parallel to the lens barrel axis m and deviates from the lens barrel axis m of the electron microscope by a first distance d. 1 .

[0055] The second centering component 13 can be located in the lens barrel of the electron microscope. For example, the second centering component 13 can be fixedly arranged on the side wall of the lens barrel of the electron microscope. The second centering components 13 are symmetrically distributed along the lens barrel axis m. An electrical signal is applied to the second centering component 13. After the electrical signal is applied, the second centering component 13 can control the electron beam to deflect in a direction close to the lens barrel axis m, so that the distance between the deflected electron beam and the lens barrel axis m is less than a preset distance.

[0056] In some examples, the preset distance can be set according to the usage scenario. In the present application, the electron detection device is applied to an electron microscope. In the electron microscope application scenario, the preset distance that can be set includes but is not limited to 0, 10μm, 30μm, 50μm, 70μm, 100μm, 150μm, 200μm, 250μm, etc. It should be noted that when the preset distance is 0, it means that the deflected electron beam coincides with the axis m of the lens barrel.

[0057] The distance between the deflected electron beam and the axis m of the lens barrel is controlled within a preset distance, thereby ensuring the quality of the beam spot formed when the electron beam acts on the test sample and avoiding the reduction of the beam spot quality.

[0058] The objective lens 14 is located in the lens barrel of the electron microscope. The objective lens 14 can be an immersion objective lens, a non-immersion objective lens, a semi-immersion objective lens, an electromagnetic composite objective lens, etc. The electron beam deflected by the second centering component 13 can be focused onto the test sample through the objective lens 14.

[0059] The sample stage 15 is located outside the lens barrel of the electron microscope. A deceleration voltage can be applied to the sample stage, and the direction of the deceleration voltage is opposite to the voltage direction of the electron beam emitted by the electron beam emission source, thereby decelerating the electron beam acting on the test sample to prevent the energy of the electron beam from being too high and causing damage to the surface of the test sample.

[0060] The detector assembly 12 deviates from the lens barrel axis m by a certain distance to avoid the electron beam and receive the return electron signal. The detector assembly 12 can be located in the lens barrel of the electron microscope, for example, the detector assembly 12 can be fixedly arranged on the side wall of the lens barrel of the electron microscope.

[0061] The detector assembly 12 may include at least one detector 121. The detector 121 may be a semiconductor detector, a microchannel plate detector, a scintillator detector or the like.

[0062] The test sample can be a semiconductor wafer, a mask, an integrated circuit board, etc.

[0063] The test sample generates a return electron signal such as a backscattered electron signal or a secondary electron signal under the interaction of the electron beam voltage and the deceleration voltage, and the energy of the return electron signal is less than the electron beam energy. The return electron signal passes through the second centering component 13 after applying the electric signal, and the second centering component 13 applying the electric signal controls the return electron signal to deflect in a direction away from the axis m of the lens barrel. Since the energy of the return electron signal is less than the energy of the electron beam, the deflection angle of the return electron signal is greater than the deflection angle of the electron beam, so that the detector component 12 can avoid the electron beam and receive the return electron signal.

[0064] In the embodiment of the present application, on the path of the electron beam moving to the test sample, the electron beam can be deflected in different directions by the first centering component and the second centering component, thereby enabling the electron beam to act on the test sample according to the emission direction of the electron beam, so that the return electron signal detected by the detector is a valid signal. On the movement path of the return electron signal, the return electron signal can be deflected by the second centering component. Since the energy of the return electron signal is less than the energy of the electron beam, the deflection angles of the return electron signal and the electron beam in the second centering component are different. The smaller the energy of the electron signal, the larger the deflection angle, so that the detector can avoid the electron beam and detect the return electron signal, and then the detection of the return electron signal can be achieved without applying any voltage to the detector, thereby avoiding the influence of the high-voltage electric field on the movement path of the electron beam and improving the quality of the electron beam.

[0065] Figure 3 A schematic structural diagram of a first centering component provided in an embodiment of the present application.

[0066] In some embodiments, optionally, as in the present application Figure 2The specific structure of the first centering assembly 11 shown in FIG. Figure 3 .like Figure 3 As shown, the first centering component 11 may include: a first centering component 111 and a second centering component 112 which are sequentially arranged along the axial direction of the lens barrel and close to the sample stage 15. The first centering component 111 is used to control the electron beam to deflect by a first preset angle so that the deflected electron beam is away from the lens barrel axis m. The second centering component 112 is used to control the electron beam deflected by the first preset angle to deflect again so that the electron beam deflected again deviates from the lens barrel axis m of the electron microscope by a first distance and is parallel to the lens barrel axis m.

[0067] The first centering component 111 is used to receive an electrical signal, so as to control the electron beam to deflect by a first preset angle in a direction away from the lens barrel axis m. The electrical signal may be a voltage signal or a current signal. For ease of description, in this embodiment, the movement path of the electron beam in the first centering component is described by taking the electrical signal as a voltage signal as an example. After the first centering component 111 receives the voltage signal, an electric field is formed in the first centering component 111. Under the action of the electric field, the electron beam will gradually deviate from the lens barrel axis m along the direction of the electric field until it deviates to the first preset angle.

[0068] The first preset angle can be understood as the angle between the moving direction of the deflected electron beam and the lens barrel axis m. The first preset angle is determined by the electrical signal applied to the first centering component 111. The larger the electrical signal, the larger the first preset angle.

[0069] The second centering component 112 is used to receive an electrical signal, the magnitude of which is the same as the magnitude of the electrical signal applied to the first centering component, and the direction is opposite, so as to control the electron beam deflected by the first preset angle to deflect in a direction close to the axis m of the lens barrel, and the electrical signal can be a voltage signal or a current signal. For ease of description, in this embodiment, the movement path of the electron beam in the second centering component is described by taking the electrical signal as a voltage signal as an example. After the second centering component 112 receives the voltage signal, an electric field is formed in the first centering component 112, and under the action of the electric field, the electron beam will gradually approach the axis m of the lens barrel along the direction of the electric field until it is parallel to the axis m of the lens barrel.

[0070] By applying electric signals in opposite directions to the first centering component 111 and the second centering component 112, the electron beam can move along a trajectory parallel to and at a certain distance from the axis m of the lens barrel, so that the electron beam can act on the sample according to the emission direction after passing through the second centering component 13.

[0071] Figure 4 A schematic structural diagram of a second centering component provided in an embodiment of the present application.

[0072] In some embodiments, optionally, as in the present application Figure 2 The specific structure of the second centering assembly 13 shown in FIG. Figure 4 .like Figure 4 As shown, the second centering component 13 may include a third centering component 131 and a fourth centering component 132 which are sequentially arranged along a direction approaching the sample stage; the third centering component 131 is used to control the electron beam to deflect by a second preset angle so that the deflected electron beam approaches the lens barrel axis m; the fourth centering component 132 is used to control the electron beam deflected by the second preset angle to be deflected again so that the distance between the electron beam deflected again and the lens barrel axis m is less than a preset distance.

[0073] The third centering component 131 is used to receive an electrical signal, and the direction of the electrical signal is the same as the electrical signal applied to the second centering component 112, and the direction is the same. Thereby controlling the electron beam deflected by the first centering component 11 to deflect to a second preset angle in a direction close to the axis m of the lens barrel, and the electrical signal can be a voltage signal or a current signal. For ease of description, in this embodiment, the movement path of the electron beam in the third centering component 131 is described by taking the electrical signal as a voltage signal as an example. After the third centering component 131 receives the voltage signal, an electric field is formed in the third centering component 131, and under the action of the electric field, the electron beam will gradually deflect toward the axis m of the lens barrel along the direction of the electric field until it deviates to the second preset angle.

[0074] The second preset angle can be understood as the angle between the moving direction of the electron beam after being deflected by the third centering component 131 and the moving direction of the electron beam after being deflected by the first centering component 11 (the direction is parallel to the barrel axis m). The second preset angle is determined by the electrical signal applied to the third centering component 131. The larger the electrical signal, the larger the second preset angle. If the voltage applied to the third centering component 131 is equal to the voltage applied to the first centering component 11, then the second preset angle is equal to the first preset angle.

[0075] The fourth centering component 132 is used to receive an electrical signal, the magnitude of which is the same as the magnitude of the electrical signal applied to the third centering component 131, and the direction is opposite, so as to control the electron beam deflected by the second preset angle to deflect in a direction away from the lens barrel axis m, and the electrical signal can be a voltage signal or a current signal. For ease of description, in this embodiment, the movement path of the electron beam in the fourth centering component 132 is described by taking the electrical signal as a voltage signal as an example. After the fourth centering component 132 receives the voltage signal, an electric field is formed in the fourth centering component 132. Under the action of the electric field, the electron beam deflected by the second preset angle no longer continues to move in the direction of the second preset angle, but gradually moves in the direction close to the lens barrel axis m along the direction of the electric field until the distance from the lens barrel axis m is less than the preset distance.

[0076] By applying electric signals in opposite directions to the third centering component 131 and the fourth centering component 132, the trajectory movement of the electron beam parallel to the lens barrel axis m and at a certain distance is deflected to coincide with the lens barrel, so that the electron beam can act on the sample in the emission direction.

[0077] In some embodiments, optionally, as in the present application Figure 3 The first centering component 111, the second centering component 112 and the Figure 4 Any of the third centering components 131 and the fourth centering components 132 shown may include: a first conductive electrode plate 111 a and a second conductive electrode plate 111 b .

[0078] The first conductive plate 111 a may be used to receive a voltage signal or be grounded.

[0079] When the first conductive electrode plate 111a receives a voltage signal, the second conductive electrode plate 111b can be used to receive a voltage signal different from the voltage signal, or be grounded, so as to form a voltage difference between the first conductive electrode plate 111a and the second conductive electrode plate 111b, thereby forming an electric field.

[0080] When the first conductive electrode plate 111 a is grounded, the second conductive electrode plate 111 b may be used to receive a voltage signal, thereby forming a voltage difference between the first conductive electrode plate 111 a and the second conductive electrode plate 111 b , thereby forming an electric field.

[0081] By applying a voltage to the first conductive electrode plate 111a and the second conductive electrode plate 111b of the first centering component 111, an electric field is formed between the first conductive electrode plate 111a and the second conductive electrode plate 111b of the first centering component 111. Under the action of the electric field, the electron beam passing through the first centering component 111 is deflected by a first preset angle toward the direction of the lens barrel axis m. By applying a voltage to the first conductive electrode plate 111a and the second conductive electrode plate 111b of the second centering component 112, an electric field is formed between the first conductive electrode plate 111a and the second conductive electrode plate 111b of the second centering component 112. Under the action of the electric field, the electron beam gradually approaches the lens barrel axis m along the direction of the electric field until it is parallel to the lens barrel axis m.

[0082] By applying voltage to the first conductive electrode plate 111a and the second conductive electrode plate 111b of the third centering component 131, an electric field is formed between the first conductive electrode plate 111a and the second conductive electrode plate 111b of the third centering component. Under the action of the electric field, the electron beam passing through the third centering component 131 is deflected by a second preset angle toward the direction of the lens barrel axis m. By applying voltage to the first conductive electrode plate 111a and the second conductive electrode plate 111b of the fourth centering component 132, an electric field is formed between the first conductive electrode plate 111a and the second conductive electrode plate 111b of the fourth centering component 132. The direction of the electric field is different from the direction of the electric field formed in the third centering component 131. Therefore, the electron beam deflected by the second preset angle toward the direction of the lens barrel axis m moves toward the direction close to the lens barrel axis m until the distance from the lens barrel axis m is less than the preset distance, so that the electron beam acts on the test sample while deviating from the lens barrel axis m by the preset distance.

[0083] By applying corresponding voltages to the first conductive electrode plate 111a and the second conductive electrode plate 111b in the first centering component 111 and the second centering component 112, respectively, the electron beam can move along a trajectory parallel to and a certain distance from the lens barrel axis m; by applying corresponding voltages to the first conductive electrode plate 111a and the second conductive electrode plate 111b in the third centering component 131 and the fourth centering component 132, respectively, the trajectory movement of the electron beam parallel to and a certain distance from the lens barrel axis m is deflected to a distance within a preset distance range from the lens barrel axis m, thereby causing the electron beam to act on the sample within a preset distance range from the lens barrel axis m.

[0084] In some embodiments, optionally, as in the present application Figure 3 The first centering component 111, the second centering component 112 and the Figure 4 Any of the third centering components 131 and the fourth centering components 132 shown may include a conductive coil.

[0085] By applying corresponding currents to the conductive coils in the first centering component 111 and the second centering component 112, respectively, the electron beam can move along a trajectory parallel to and a certain distance from the lens barrel axis m; by applying corresponding currents to the conductive coils in the third centering component 131 and the fourth centering component 132, respectively, the trajectory movement of the electron beam parallel to and a certain distance from the lens barrel axis m is deflected to a distance within a preset distance range from the lens barrel axis m, thereby causing the electron beam to act on the sample within a preset distance range from the lens barrel axis m.

[0086] In some embodiments, optionally, the present application Figure 2 The detector 121 shown in the figure may include a receiving surface, which is located on a side of the detector close to the objective lens, and the receiving surface may be used to receive the returned electronic signal.

[0087] Since the energy of the electron beam and the return electron signal is different, the deflection angles of the two are different. The smaller the energy, the larger the deflection angle. Therefore, the motion trajectory of the return electron signal is different from the motion trajectory of the electron beam. Therefore, the second centering component 13 controls the return electron signal to be deflected. The deflected return electron signal is at a second distance d from the lens barrel axis m. 2 greater than the first distance d from the deflected electron beam to the axis m of the lens tube 1 , the distance D between the detector and the axis m of the lens tube and the first distance d 1 , the second distance d 2 Between 1 <D<d 2 , so that the detector 121 can collect the returning electronic signal through the receiving surface.

[0088] Figure 5 A schematic diagram of the structure of a detector provided in an embodiment of the present application.

[0089] In some embodiments, optionally, the present application Figure 2 The specific structure of the detector 121 shown can be referred to Figure 5 .like Figure 5 As shown, the detector 121 may include a plurality of sub-receiving surfaces 41 sequentially arranged along the radial direction of the lens barrel, and each sub-receiving surface 41 may be used to receive return electronic signals of different energies.

[0090] The return electron signal is deflected after passing through the second centering component 13. The energy of the return electron signal is different, and the deflection angle of the return electron signal is different. After being deflected by the second centering component 13, when acting on the detector receiving surface, the distance from the lens barrel axis m is different. The greater the energy of the return electron signal, the closer it is to the lens barrel axis m, so that the return electron signals of different energies can be collected by multiple sub-receiving surfaces 41 arranged in sequence along the radial direction of the lens barrel, so that the electron microscope can perform separate imaging of the return electron signals of different energies.

[0091] In some embodiments, optionally, the present application Figure 2 The electronic detection device shown may also include a signal synthesizer (not shown in the figure), and the number of signal synthesizers may be set according to the use requirements. The signal synthesizer may be used to connect to multiple sub-receiving surfaces, synthesize the return electronic signals detected by the multiple sub-receiving surfaces, and output an electronic signal synthesized image, thereby realizing hybrid imaging.

[0092] In order to better understand the embodiments of the present application, Figure 2 The electron beam and the return electron signal are Figure 2 The motion process in the electronic detection device shown in FIG. Figure 2In the electron detection device shown, the electron beam reflection source is coaxial with the lens barrel of the electron microscope, the first centering component 11 is symmetrical about the lens barrel axis m, the second centering component 13 is symmetrical about the lens barrel axis m, and the detector component 12 includes a detector 121, which is located on one side of the lens barrel axis m. The distance between the first centering component 11 and the lens barrel axis m is The distance between the first centering assembly 12 and the lens barrel axis m is

[0093] The energy of the electron beam emitted by the electron beam emission source can be E 1 , for example, 10keV, 12keV, 14keV, 16keV, etc. The energy can also be expressed as the acceleration voltage U 1 For example, if the energy of the electron beam is 10 keV, then the acceleration voltage of the electron beam is 10 kV. The deceleration energy applied to the sample stage can be E 2 , E 2 <E 1 For example, E 2 It can be 500eV, 800eV, 1keV, 2keV, 3keV, etc. The deceleration energy can also be expressed as the deceleration voltage U 2 To express, thus, the equivalent voltage U of the return electronic signal generated 3 =U 1 -U 2 .

[0094] A voltage ΔV is applied to the first centering component 11. 1 , a voltage ΔV is applied to the second centering component 13 2 , the effective length of the first centering component 11 is h 1 , the effective length h of the second centering assembly 13 2 The effective length may be understood as the length of the region in the first centering component or the second centering component where the electron beam is deflected.

[0095] Voltage ΔV 1 Including sub-voltage ΔV′ 1 and sub-voltage ΔV" 1 . Sub-voltage ΔV′ 1 and sub-voltage ΔV" 1 The value of the voltage ΔV 1 The value of the sub-voltage ΔV′ is the same 1 and sub-voltage ΔV" 1 The direction is opposite. Sub voltage ΔV′ 1 Corresponding to the first field 101 of the first pair of components 11, the sub-voltage ΔV" 1 The second field region 102 corresponds to the first pair of components 11. The first pair of components 11 is at a sub-voltage ΔV′ 1 and sub-voltage ΔV"1 The sub-electric field ΔE′ is formed under the action of 1 and the sub-electric field ΔE" 1 , sub-electric field ΔE′ 1 and the sub-electric field ΔE" 1 Perpendicular to the axis m of the lens tube and the sub-electric field ΔE′ 1 and the sub-electric field ΔE" 1 When the electron beam passes through the first centering component 11, it first passes through the sub-electric field ΔE′ 1 The sub-electric field ΔE′ in the region 1 Make the electron beam follow the sub-electric field ΔE′ 1 The direction of the electron beam is deflected for the first time, and the deflection angle is α. At this time, the direction of the electron beam is deflected by an angle α with the axis m of the lens tube. Then it passes through the sub-electric field ΔE" 1 The area where the sub-electric field is located is ΔE" 1 Make the electron beam follow the sub-electric field ΔE" 1 The direction of the electron beam is deflected for the second time, and the deflection angle is α. At this time, the movement direction of the electron beam is parallel to the axis m of the lens tube, and the first distance d from the axis m of the electron microscope 1 ,in,

[0096] It should be noted that this application Figure 2 In the example shown, the sub-electric field ΔE′ 1 The direction is X direction, the sub-electric field ΔE" 1 The direction is the Y direction, but is not limited thereto. 1 The direction is determined by ΔV′ of the first field region 101 in the first centering component 11 1 Determined by ΔV′ 1 represents the potential difference formed by the first pair of components in the first field region 101, the sub-field ΔE" 1 The direction is determined by ΔV" of the second field 102 in the first centering component 11 1 Determined by ΔV" 1 denoted as the potential difference formed by the first pair of components in the second field region 102 .

[0097] Voltage ΔV 2 Including sub-voltage ΔV′ 2 and sub-voltage ΔV" 2 . Sub-voltage ΔV′ 2 and sub-voltage ΔV" 2 The value of the voltage ΔV 2 The value of the sub-voltage ΔV′ is the same 2 and sub-voltage ΔV" 2 The direction is opposite. Sub voltage ΔV′ 2 Corresponding to the first field region of the second pair of components 13, the sub-voltage ΔV"2 The second field region corresponding to the second pair of components 13. The second pair of components 13 at the sub-voltage ΔV′ 2 and sub-voltage ΔV" 2 The sub-electric field ΔE′ is formed under the action of 2 and the sub-electric field ΔE" 2 , sub-electric field ΔE′ 2 and the sub-electric field ΔE" 2 Perpendicular to the axis m of the lens tube and the sub-electric field ΔE′ 2 and the sub-electric field ΔE" 2 When the electron beam passes through the second centering assembly 13, it first passes through the sub-electric field ΔE′ 2 The sub-electric field ΔE′ in the region 2 Make the electron beam follow the sub-electric field ΔE′ 2 The direction of the first deflection occurs, the deflection angle is β, and then passes through the sub-electric field ΔE" 2 The area where the sub-electric field is located is ΔE" 2 Make the electron beam follow the sub-electric field ΔE" 2 The second deflection occurs in the direction of the electron beam, and the deflection angle is β. At this time, the movement direction of the electron beam coincides or substantially coincides with the axis m of the lens barrel. Whether the deflection angle α and the deflection angle β are the same depends on the voltage ΔV 2 and voltage ΔV 1 Are they the same, voltage ΔV 2 and voltage ΔV 1 can be considered as controlled. In this example, the voltage ΔV 2 and voltage ΔV 1 The electron beam is described as being equal to each other, so that the electron beam can hit the test sample along the axis m of the lens barrel, thereby ensuring the quality of the electron beam spot on the test sample.

[0098] It should be noted that this application Figure 2 In the example shown, the sub-electric field ΔE′ 2 The direction is Y direction, and the sub-electric field ΔE" 2 The direction is the X direction, but not limited to this. 2 The direction is determined by ΔV′ of the first field region in the second centering component 13. 2 Determined by ΔV′ 2 represents the potential difference formed by the components in the second pair in the first field region, the sub-field ΔE" 2 The direction is determined by ΔV" in the second field of the second centering component 13 2 Determined by ΔV" 2 Represents the potential difference formed by the components in the second pair in the second field region.

[0099] The electron beam converged by the objective lens 14 acts on the test sample placed on the sample stage 15, and the test sample generates a return electron signal. The energy of the return electron signal is E 3 .

[0100] When the returning electronic signal passes through the second centering component 13, it first passes through the sub-electric field ΔE′ 2 The sub-electric field ΔE′ in the region 2 Make the return electron signal along the sub-electric field ΔE′ 2 The first deflection occurs in the direction of the electron beam, and the deflection angle is γ. Since the energy of the returning electron signal is less than the energy of the electron beam, the deflection angle of the returning electron signal is γ, which is greater than the deflection angle β of the electron beam. Then it passes through the sub-electric field ΔE" 2 The area where the sub-electric field is located is ΔE" 2 Make the return electron signal along the sub-electric field ΔE" 2 The direction of the electron signal is deflected for the second time, and the deflection angle is γ. At this time, the direction of the return electron signal is parallel to the axis m of the lens barrel, and the first distance d from the axis m of the electron microscope 2 ,in,

[0101] The returning electronic signal passes through the second centering assembly 13 and is collected by the detector.

[0102] It should be noted that the field region in this example can be understood as the electric field region formed in the centering component.

[0103] In this example, on the path of the electron beam moving to the test sample, the first centering component 11 and the second centering component 13 can realize the deflection of the electron beam in different directions, so that the electron beam can act on the test sample according to the emission direction of the electron beam, so that the return electron signal detected by the detector 121 is a valid signal. The return electron signal can be deflected by the second centering component 13 on the movement path of the return electron signal. Since the energy of the return electron signal is less than the energy of the electron beam, the deflection angles of the return electron signal and the electron beam in the second centering component 13 are different. The smaller the energy of the electron signal, the larger the deflection angle. In this way, the detector 121 will not block the movement path of the electron beam to the test sample, and can also detect the return electron signal. Therefore, the return electron signal can be collected without applying any voltage to the detector 121, thereby avoiding the influence of the high-voltage electric field on the movement path of the electron beam and improving the quality of the electron beam.

[0104] In order to better understand the embodiments of the present application, Figure 5 The return electron signals of different energies are described in this application as follows Figure 2 The motion process in the electronic detection device shown is explained.

[0105] The returned electronic signal may contain electronic signals of various energies, and the detector 121 may simultaneously collect electronic signals of different energies through different sub-receiving surfaces 41. The smaller the energy of the returned electronic signal, the farther the distance from the lens barrel axis m.

[0106] The voltage of the electronic signal with the largest energy among the returned electronic signals is recorded as U max , the pressure difference between the electronic signal of other energies and the electronic signal with the largest energy is recorded as ΔU, then when the return electronic signal is collected by the detector, the distance L from the axis of the lens barrel can be expressed as:

[0107] In such Figure 5 In the example shown, the detector may include a plurality of sub-receiving surfaces 41. Each sub-receiving surface 41 is used to receive return electronic signals of different energies. m The returned electron signal of the energy can be obtained by calculation, and the area corresponding to the returned electron signal of the energy can be obtained by using a microscope to obtain the returned electron signal received by the sub-receiving surface 41 where the area is located for imaging.

[0108] Each sub-receiving surface 41 receives the returned electron signals with different energies, thereby achieving separate imaging of the returned electron signals with different energies by the electron microscope.

[0109] The energy of the returned electronic signal is different, and the deflection angle of the second centering component 13 to the returned electronic signal is different. After being deflected by the second centering component 13, when the returned electronic signal acts on the detector receiving surface, the distance from the lens barrel axis m is different. The greater the energy of the returned electronic signal, the closer it is to the lens barrel axis m, so that the returned electronic signals of different energies can be collected by a plurality of sub-receiving surfaces 41 arranged in sequence along the radial direction of the lens barrel, so that the electron microscope can perform separate imaging of the returned electronic signals of different energies.

[0110] Based on the above detection device, an embodiment of the present application also provides an electronic signal detection method.

[0111] Figure 6 A schematic diagram of a flow chart of an electronic signal detection method provided in an embodiment of the present application. Figure 6 As shown, the electronic signal detection method provided by the present application may include:

[0112] S10, applying a first electrical signal to the first centering component, and controlling the electron beam deflection through the first centering component after the first electrical signal is applied, so that the deflected electron beam deviates from the axis of the electron microscope barrel by a first distance.

[0113] S11, applying a second electrical signal to the second centering component, and controlling the deflected electron beam to deflect again through the second centering component after the second electrical signal is applied, so that the distance between the re-deflected electron beam and the axis of the lens barrel is less than a preset distance.

[0114] S12. Converging the electron beam deflected by the second centering component after applying the second electrical signal through the objective lens, and making the converged electron beam act on the test sample placed on the sample stage, so that the test sample generates a return electron signal, and the energy of the return electron signal is less than the energy of the electron beam.

[0115] S13, controlling the deflection of the return electronic signal through the second centering component after applying the second electrical signal, so that the deflected return electronic signal deviates from the axis of the lens barrel by a second distance.

[0116] S14. Receive the deflected return electronic signal through the detector assembly.

[0117] In this embodiment, by applying a first electrical signal to the first centering component and applying a second electrical signal to the second centering component, the electron beam can be deflected in different directions by the first centering component and the second centering component on the path of the electron beam moving to the test sample, thereby enabling the electron beam to act on the test sample according to the emission direction of the electron beam, so that the return electron signal detected by the detector is a valid signal. The return electron signal can be deflected by the second centering component on the movement path of the return electron signal. Since the energy of the return electron signal is less than the energy of the electron beam, the deflection angles of the return electron signal and the electron beam in the second centering component are different. The smaller the energy of the electron signal, the larger the deflection angle. In this way, the detector will not block the movement path of the electron beam to the test sample, and can also detect the return electron signal. Therefore, the return electron signal can be collected without applying any voltage to the detector, thereby avoiding the influence of the high-voltage electric field on the movement path of the electron beam and improving the quality of the electron beam.

[0118] In some embodiments, optionally, the present application Figure 6 Step S14 in the illustrated electronic signal detection method may include: receiving a return electronic signal of corresponding energy through each sub-receiving surface of the detector in the detector assembly.

[0119] The energy of the returned electron signal is different, and the deflection angle of the second centering component to the returned electron signal is different. After being deflected by the second centering component, the distance from the axis of the lens barrel when the returned electron signal acts on the detector receiving surface is different. The greater the energy of the returned electron signal, the closer it is to the axis of the lens barrel, so that the returned electron signals of different energies can be collected by multiple sub-receiving surfaces arranged in sequence along the radial direction of the lens barrel, so that the electron microscope can image the returned electron signals of different energies separately.

[0120] Based on the above detection device, an embodiment of the present application also provides an electron microscope.

[0121] Figure 7 This is a schematic diagram of the structure of an electron microscope provided in an embodiment of the present application. Figure 7 As shown, the electron microscope 1 may include an electron beam emission source 3 and Figure 2 The electronic detection device 10 is shown.

[0122] Electron microscopes include, but are not limited to, transmission electron microscopes, scanning electron microscopes, and scanning transmission electron microscopes.

[0123] The uses of electron microscopes include, but are not limited to, detecting patterns on semiconductor silicon wafers and masks and measuring key dimensions, and detecting open circuit defects and short circuit defects in electronic components on integrated circuit boards.

[0124] The electron microscope of this embodiment can realize deflection of the electron beam in different directions by the first centering component and the second centering component in the electron detection device on the path of the electron beam moving to the test sample, thereby enabling the electron beam to act on the test sample according to the emission direction of the electron beam, so that the return electron signal detected by the detector in the electron detection device is a valid signal. The return electron signal can be deflected by the second centering component in the electron detection device on the movement path of the return electron signal. Since the energy of the return electron signal is less than the energy of the electron beam, the deflection angles of the return electron signal and the electron beam in the second centering component are different. The smaller the energy of the electron signal, the larger the deflection angle. Thus, the detector can avoid the electron beam and detect the return electron signal. Further, the detection of the return electron signal can be realized without applying any voltage to the detector, thereby avoiding the influence of the high voltage electric field on the movement path of the electron beam, improving the quality of the electron beam, and improving the imaging quality of the electronic signal.

[0125] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. An electronic detection device, characterized in that: Applied to an electron microscope, the electron detection device comprises: a first centering component, a detector component, a second centering component, an objective lens and a sample stage for placing a test sample; The first centering assembly is used to control the deflection of the electron beam so that the deflected electron beam deviates from the axis of the electron microscope barrel by a first distance; The second centering component is used to control the deflected electron beam to deflect again, so that the distance between the re-deflected electron beam and the axis of the lens barrel is less than a preset distance; The objective lens is used to converge the electron beam after being deflected by the second centering component, and make the converged electron beam act on the test sample, so that the test sample generates a return electron signal under the action of the electron beam, and the energy of the return electron signal is less than the energy of the electron beam; The second centering component is also used to control the deflection of the return electronic signal so that the deflected return electronic signal deviates from the axis of the lens barrel by a second distance; The detector assembly deviates from the lens barrel axis to avoid the electron beam passing through the first centering assembly, and the detector assembly is used to receive the deflected return electron signal.

2. The electronic detection device according to claim 1, characterized in that: The first centering component, the detector component, the second centering component, the objective lens and the sample stage are sequentially arranged along the axis of the lens barrel; The first centering assembly comprises a first centering component and a second centering component which are sequentially arranged along the axis direction of the lens barrel; The first centering component is used to control the electron beam to deflect by a first preset angle in a direction away from the axis of the lens barrel; The second centering component is used to control the electron beam deflected by the first preset angle to be deflected again toward the direction close to the axis of the lens barrel, so that the re-deflected electron beam deviates from the axis of the lens barrel of the electron microscope by the first distance.

3. The electronic detection device according to claim 2, characterized in that: The second centering assembly comprises a third centering component and a fourth centering component which are sequentially arranged along the axis direction of the lens barrel; The third centering component is used to control the electron beam to deflect toward a direction close to the axis of the lens barrel by a second preset angle; The fourth centering component is used to control the electron beam deflected by the second preset angle to be deflected again in a direction away from the axis of the lens barrel, so that the distance between the electron beam after the deflection is less than the preset distance from the axis of the lens barrel.

4. The electronic detection device according to claim 3, characterized in that: Any of the first centering component, the second centering component, the third centering component or the fourth centering component comprises: A first conductive electrode plate and a second conductive electrode plate.

5. The electronic detection device according to claim 3, characterized in that: Any of the first centering member, the second centering member, the third centering member, or the fourth centering member includes a conductive coil.

6. The electron detection device according to any one of claims 1 to 5, characterized in that: The detector assembly includes at least one detector, wherein the detector includes a receiving surface for receiving a returning electronic signal.

7. The electronic detection device according to claim 6, characterized in that: The receiving surface includes a plurality of sub-receiving surfaces arranged in sequence along the radial direction of the lens barrel, and each of the sub-receiving surfaces is used to receive a return electronic signal of corresponding energy.

8. An electronic signal detection method, characterized in that: Applied to the electronic detection device according to any one of claims 1 to 7, the method comprises: Applying a first electrical signal to the first centering component, and controlling the electron beam deflection through the first centering component after the first electrical signal is applied, so that the deflected electron beam deviates from the axis of the electron microscope barrel by a first distance; Applying a second electrical signal to the second centering component, and controlling the deflected electron beam to deflect again through the second centering component after the second electrical signal is applied, so that the distance between the electron beam after the deflection is less than a preset distance from the axis of the lens barrel; Converging the electron beam deflected by the second centering component after the second electrical signal is applied through an objective lens, and causing the converged electron beam to act on a test sample placed on the sample stage, so that the test sample generates a return electron signal, the energy of which is less than the energy of the electron beam; Controlling the deflection of the return electronic signal by the second centering component after applying the second electrical signal, so that the deflected return electronic signal deviates from the axis of the lens barrel by a second distance; The deflected return electron signal is received by the detector assembly.

9. The method according to claim 8, characterized in that The detector assembly comprises at least one detector, the detector comprises a receiving surface, and the receiving surface comprises a plurality of sub-receiving surfaces sequentially arranged along the radial direction of the lens barrel; The step of receiving the deflected return electronic signal through the detector assembly comprises: A return electron signal of corresponding energy is received by each sub-receiving surface of the detector in the detector assembly.

10. An electron microscope, characterized in that: Comprising the electronic detection device according to any one of claims 1 to 7.

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