Electrostatic field deflector and method of processing the same

Abstract

The application relates to an electrostatic field deflector suitable for being installed in a scanning electron microscope, comprising a deflection electrode plate and an insulating mounting seat, the middle part of the insulating mounting seat is provided with a mounting hole, the deflection electrode plate is in the form of a cylinder as a whole, the outer side wall is matched with the mounting hole, the deflection electrode plate is fixed in the mounting hole, and the middle part of the deflection electrode plate is provided with an optical axis hole coaxially arranged with the mounting hole, wherein the deflection electrode plate is divided into an even number of deflection electrode blocks along the radial direction. The deflection electrode plate is fixed in the insulating mounting seat, the optical axis hole of the deflection electrode plate is coaxially arranged with the mounting hole, the electron beam can pass through the geometric center of the electrostatic field deflector as vertically as possible, the deflection electrode plate is evenly cut into an even number of deflection electrode blocks along the radial direction, opposite two deflection electrode blocks form an electrostatic field, the uniformity of the electrostatic field is effectively improved, the scanning electron microscope is reduced in phase difference, the resolution is improved, the detection precision is improved, and the scanning electron microscope can be applied to a higher process production line.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor, in particular to a static electric field deflector and a processing method thereof. BACKGROUND

[0002] With the development of semiconductor technology and the progress of process technology, the integrated circuit line width is increasingly developed to be fine, and the production process technology of the circuit is also required to be higher and more difficult. Not only sub-micron lines are etched, but also line defects are controlled within a certain range to ensure the function and yield of the chip.

[0003] When the size of the defect is more than one-third of the feature line width, the defect becomes a fatal defect that can cause device failure. As the size of the device is continuously reduced, the size of the fatal defect becomes smaller and smaller, and the detection of the defect becomes more difficult. The optical detection equipment cannot meet the needs, and the electron beam detection equipment overcomes the limitation of the optical wavelength, and the resolution is improved to the nanometer field, so that extremely small defects can be detected. The core of the electron beam detection equipment is a scanning electron microscope, which images by point-by-point scanning of the electron beam. The deflector has two types of electrostatic deflector and magnetic deflector. The electrostatic deflection has the advantage of fast scanning speed compared with the magnetic deflection. However, compared with the magnetic deflection, the electrostatic field in the electrostatic field deflector is more uneven, which can cause greater phase difference and is not conducive to the centering of the scanning electron microscope. SUMMARY

[0004] Therefore, the present application provides a static electric field deflector which is suitable for being installed in a scanning electron microscope, comprising a deflection electrode plate and an insulating mounting seat; the insulating mounting seat has a mounting hole in the middle; the deflection electrode plate is in the shape of a cylinder as a whole, and the outer sidewall is matched with the mounting hole; the deflection electrode plate is fixed in the mounting hole, and the middle part of the deflection electrode plate has an optical axis hole which is coaxially arranged with the mounting hole; wherein the deflection electrode plate is divided into an even number of deflection electrode blocks along the radial direction.

[0005] In a possible implementation method, the upper sidewall of the deflection electrode block extends outwardly from the insulating mounting seat and has a first extension part, the upper surface of the first extension part is lower than the upper surface of the deflection electrode block, and the lower surface of the first extension part is in contact with the upper surface of the insulating mounting seat.

[0006] In a possible implementation method, the deflection electrode plate is a cylinder, and a groove is arranged on the sidewall surface of the deflection electrode plate which does not extend the first extension part, and the sidewall surface is in contact with the inner wall of the mounting hole.

[0007] In a possible implementation method, the deflection electrode plate is divided into eight deflection electrode blocks on average.

[0008] In a possible implementation, the deflection electrode plate is made of beryllium copper; and the insulating mounting seat is made of ceramic.

[0009] In a possible implementation, the upper sidewall of the insulating mounting seat extends outwardly with a second extension, which has a ring structure in the vertical direction, and four fixing screw holes are formed in the second extension, the axial distance of the fixing screw holes to the mounting hole is equal, and the connecting line of adjacent fixing screw holes forms a square structure; the first extension on each deflection electrode block is spliced into a ring structure in the vertical direction, and the outer diameter of the ring structure of the deflection electrode block is smaller than the outer diameter of the ring structure of the second extension; the upper surface of the first extension is provided with a wire pressing hole, and the sidewall is provided with a wire inlet hole.

[0010] In another aspect, the application provides a processing method of an electrostatic field deflector, the upper sidewall of the deflection electrode block extends outwardly from the insulating mounting seat with a first extension, the upper surface of the first extension is lower than the upper surface of the deflection electrode block, and the lower surface of the first extension is in contact with the upper surface of the insulating mounting seat; the deflection electrode plate is a cylinder, and a groove is formed in the sidewall surface of the deflection electrode plate without the first extension and in contact with the inner wall of the mounting hole; the method comprises the following steps: rough machining the deflection electrode plate to be processed to form a deflection electrode plate initial type with the upper sidewall being the first extension and the sidewall without the first extension being provided with a groove; processing the electrostatic field deflector; comprising the following steps: rough machining the deflection electrode plate to be processed to form a deflection electrode plate initial type with the upper sidewall being the extension and the sidewall without the extension being provided with a groove; rough machining the insulating mounting seat to be processed to form a mounting seat initial type with the mounting hole in the middle; coating adhesive in the groove of the deflection electrode plate and / or the inner wall of the mounting hole of the insulating mounting seat, and waiting for a preset time after the deflection electrode plate and the insulating mounting seat are adhesively fixed to release the adhesive stress.

[0011] In a possible implementation, the preliminary machining of the deflection electrode plate to be processed further comprises: placing the deflection electrode plate to be processed on a cutting line machining device, and machining an even number of cutting lines on the upper surface, the side surface and the lower surface of the first deflection electrode plate to be processed in the radial direction.

[0012] In a possible implementation, the upper sidewall of the insulating mounting seat extends outwardly with a second extension, the second extension has a ring structure in the vertical direction, four fixing screw holes are formed on the second extension, the axial distance from the fixing screw holes to the mounting hole is equal, and the connecting lines of adjacent fixing screw holes form a square structure; the first extension on each deflection pole piece is spliced into a ring structure in the vertical direction, and the outer diameter of the ring structure of the deflection pole piece is smaller than the outer diameter of the ring structure of the second extension; a pressing wire hole is formed on the upper surface of the first extension, and a wire inlet hole is formed on the sidewall; the sidewall of the second extension is clamped by a clamping device, and the sidewall of the insulating mounting seat without the second extension, the lower surface of the second extension, and the inner wall of the optical axis hole of the deflection pole preliminary type are sequentially finished.

[0013] In a possible implementation, the deflection pole preliminary type is cut along the cutting line using a slow wire, and is cut into eight-petal average deflection pole pieces.

[0014] The application has the following beneficial effects: by fixing the deflection pole in the insulating mounting seat and coaxially arranging the optical axis hole of the deflection pole and the mounting hole, the electron beam passes through the geometric center of the electrostatic field deflector as vertically as possible, the deflection pole is cut into an even number of deflection pole pieces along the radial direction, and the opposite two deflection pole pieces form an electrostatic field, thereby effectively improving the uniformity of the electrostatic field, reducing the phase difference of the scanning electron microscope, improving the resolution, and improving the detection precision to be applicable to a higher process production line.

[0015] Other features and aspects of the application will become apparent from the following detailed description of exemplary embodiments with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the application and serve to explain the principles of the application.

[0017] Figure 1 FIG. 1 shows a perspective view of an electrostatic field deflector according to an embodiment of the application;

[0018] Figure 2 FIG. 2 shows an installation schematic diagram of a deflector preliminary type and a mounting seat preliminary type according to an embodiment of the application;

[0019] Figure 3 FIG. 3 shows a sectional view of an electrostatic field deflector according to an embodiment of the application. DETAILED DESCRIPTION

[0020] Various exemplary embodiments, features, and aspects of the present application will be described herein below with reference to the accompanying drawings. The same reference numbers in different drawings indicate the same or similar elements. Although various aspects of embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically noted, and the drawings are not intended to limit the scope of the application unless specifically stated.

[0021] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate relative or positional relationships based on the orientation or position shown in the drawings, and are used merely for convenience and simplicity of description and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

[0022] In addition, the terms "first", "second", and the like are used merely as labels for convenience and do not necessarily indicate or imply a relative importance or a particular order of use or significance, unless specifically stated. Therefore, the features defined with "first", "second" can include one or more of the features explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is two or more, unless specifically limited otherwise.

[0023] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0024] In addition, numerous specific details are given in the following detailed description in order to provide a thorough understanding. Those of ordinary skill in the art will realize that the application can be practiced without many of the specific details given. In some instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure aspects of the application.

[0025] Figure 1 A perspective view of an electrostatic field deflector according to an embodiment of the present application is shown; Figure 2 An installation schematic view of a deflector prototype and a mounting seat prototype when installed according to an embodiment of the present application is shown; Figure 3 A cross-sectional view of an electrostatic field deflector according to an embodiment of the present application is shown.

[0026] As Figures 1-3As shown, this electrostatic field deflector is suitable for installation inside a scanning electron microscope. It includes a deflecting electrode 10 and an insulating mounting base 20. The insulating mounting base 20 has a mounting hole in the middle. The deflecting electrode 10 is cylindrical in shape, and its outer side wall is adapted to the mounting hole. The deflecting electrode 10 is fixed in the mounting hole, and the deflecting electrode 10 has an optical axis hole 102 in the middle. The optical axis hole 102 is coaxially arranged with the mounting hole. The deflecting electrode 10 is divided into an even number of deflecting electrode blocks 11 along its radial direction.

[0027] In this implementation, by fixing the deflection plate 10 inside the insulating mounting base 20, and coaxially aligning the optical axis hole 102 of the deflection plate 10 with the mounting hole, the electron beam passes through the geometric center of the electrostatic field deflector as perpendicularly as possible. Furthermore, the deflection plate 10 is evenly cut into an even number of deflection pole pieces 11 along its radial direction. Two opposing deflection pole pieces 11 form an electrostatic field, effectively improving the uniformity of the electrostatic field. This reduces the phase difference in the scanning electron microscope, increases the resolution, and improves the detection accuracy, making it suitable for production lines with higher process capabilities.

[0028] like Figure 3 As shown, in one possible implementation, the upper sidewall of the deflection pole 11 extends outward from the insulating mounting base 20 and has a first extension 101. The upper surface of the first extension 101 is lower than the upper surface of the deflection pole 11, and the lower surface of the first extension 101 is in contact with the upper surface of the insulating mounting base 20.

[0029] In this possible implementation, the upper sidewall of each deflection electrode 11 extends outward to form a first extension 101. The first extension 101 is cut into an even number of segments along with the deflection electrode 10. The lower surface of the first extension 101 can contact the upper surface of the insulating mounting base 20, ensuring from a mechanical structure perspective that the deflection electrode 11 is horizontally installed in the insulating mounting base 20, and ensuring that the electron beam exits the optical axis hole 102 as vertically as possible.

[0030] Furthermore, the longitudinal projection of a single first extension 101 is a fan ring, the inner edge of which contacts the outer wall of the deflection electrode block 11, and the lower surface of the fan ring is horizontal, so that the deflection electrode plate 10 is placed horizontally in the insulating mounting base 20, which facilitates the alignment of the scanning electron microscope and improves the resolution.

[0031] More specifically, the longitudinal projection of all the first extensions 101 is annular, and the upper surface of the deflection pole 11 is higher than the upper surface of the first extension 101. Using the upper surface of the deflection pole 11 as a base surface makes it easier for those skilled in the art to level it during processing.

[0032] In one possible implementation, the deflection plate 10 is a cylinder, and a groove is formed on the side wall surface of the deflection plate 10 without the first extension 101, which contacts the inner wall of the mounting hole.

[0033] In this implementation, the sidewall of the deflection plate 10 without the first extension 101 is the vertical plane of the deflection plate 10, and the vertical plane of the deflection plate 10 has a groove. Compared with a smooth plane, the groove can store more adhesive, and the bonding effect is better, and the connection strength is improved.

[0034] In a possible implementation method, the deflection plate 10 is evenly divided into eight deflection blocks 11.

[0035] Preferably, the deflection plate 10 is evenly divided into eight parts after cutting, and forms four pairs of electrostatic fields.

[0036] In a possible implementation method, the material of the deflection plate 10 is beryllium copper, and the material of the insulating mounting seat 20 is ceramic.

[0037] Preferably, the material of the deflection plate 10 is beryllium copper, and the material of the insulating mounting seat 20 is ceramic.

[0038] As shown in Figure 1 , Figure 2 In a possible implementation method, the upper sidewall of the insulating mounting seat 20 extends outwardly with a second extension 201, the second extension 201 has a ring structure in the vertical direction, four fixing screw holes 202 are formed on the second extension 201, the distance from the fixing screw holes 202 to the axis of the mounting hole is equal, and the line connecting the adjacent fixing screw holes 202 forms a square structure. The first extension 101 on each deflection block 11 is spliced into a ring structure in the vertical direction, and the outer diameter of the ring structure of the deflection block 11 is smaller than the outer diameter of the ring structure of the second extension 201. The upper surface of the first extension 101 is provided with a wire pressing hole 104, and the sidewall is provided with a wire inlet hole 105.

[0039] In this possible implementation, the wire inlet hole 105 is formed in the sidewall of the first extension 101 to connect the power line of the deflection plate 10, apply voltage to generate an electric field to change the direction of the electron beam, and realize the scanning function of the scanning lens. The wire pressing hole 104 is formed in the upper surface of the first extension 101, and the screw is screwed in to press the wire and fix the cable of each deflection block 11.

[0040] In this implementation, the second extension 201 extending outward from the upper sidewall of the insulating mounting base 20 also forms a ring structure. The second extension 201 is used to horizontally and stably fix the deflection plate 10 and the first extension 101 thereon. The second extension 201 is provided with fixing screw holes 202. The axial distance from the fixing screw holes 202 to the mounting holes is equal, and the line connecting adjacent fixing screw holes 202 forms a square structure, which is easy to process and ensures that the force is evenly distributed after assembly. The fixing screw holes 202 are used to screw and fix the deflection cover above the deflection plate 10. Installing the deflection cover ensures the rationality of the device design. Other components of the deflector mechanism have not been modified, so they will not be described in detail in this article.

[0041] On the other hand, this application proposes a processing method for an electrostatic field deflector, which processes the electrostatic field deflector in the above possible implementations, including the following steps: rough machining the deflection plate 10 to be processed to form a preliminary deflection plate 10 with an extension on the upper part of the side wall and grooves on the side wall without the extension; rough machining the insulating mounting base 20 to be processed to form a preliminary mounting base with a mounting hole in the middle; applying adhesive to the grooves of the deflection plate 10 and / or the inner wall of the mounting hole of the insulating mounting base 20; and waiting for a preset time after the deflection plate 10 and the insulating mounting base 20 are bonded and fixed to each other to release the bonding stress.

[0042] In one possible implementation, the preliminary processing of the deflection plate 10 to be processed further includes: placing the deflection plate 10 to be processed on a cutting wire processing device, and processing an even number of cutting lines 103 radially on the upper surface, side surface and lower surface of the first deflection plate 10 to be processed.

[0043] In the above implementation method, the beryllium copper deflection plate 10 to be processed is first roughed. It should be emphasized that the preliminary processing here leaves room for fine processing. The specific equipment and dimensions used for processing can be changed according to the specifications of the scanning electron microscope. Since this is existing technology, only one processing sequence is given in this article, and no further restrictions are made for the others.

[0044] Specifically, the first extension 101 is formed on the upper side wall of the deflection plate 10, a cylindrical body is formed in the center with an optical axis hole 102, and the first extension 101 is also formed as a cylindrical body, and a groove is formed on the side wall without the first extension 101 extending outward, the upper surface of the deflection plate 10 is higher than the upper surface of the first extension 101, so as to serve as a leveling surface for finishing; then the cutting line processing device is used to process an even number of cutting lines 103 on the upper surface, side surface and lower surface of the first deflection plate 10 along the radial direction, the cutting lines 103 at both ends of the side surface are connected with the cutting lines 103 on the upper surface and lower surface respectively, the cutting lines 103 serve as the reference line for cutting the deflection plate 10 into deflection pole pieces 11, and then the pressure line hole 104 and the wire inlet hole 105 are preliminarily processed on the first extension 101, and the foregoing processing steps are completed to form the initial type of the deflection plate 10.

[0045] Further, the ceramic insulating mounting seat 20 is rough machined to form a cylindrical body with a second extension 201 extending outward from the upper side wall, an installation hole is formed in the middle, and the second extension 201 is also machined as a cylindrical body, and a fixing screw hole 202 is formed on the surface, and the foregoing sequential machining steps are completed to form the initial type of the mounting seat.

[0046] The adhesive is coated on the groove of the side wall of the initial type of the deflection plate 10 and the inner wall of the installation hole of the initial type of the mounting seat, and after bonding, the adhesive is allowed to solidify, and it is pointed out here that after the adhesive solidifies, it still needs to be placed for a period of time to release the bonding stress, so as to avoid the bonding stress from affecting the cutting to some extent and effectively improve the yield of the electrostatic field deflector.

[0047] In a possible implementation, the upper side wall of the insulating mounting seat 20 extends outward with a second extension 201, the second extension 201 has a ring structure in the vertical direction, four fixing screw holes 202 are formed on the second extension 201, the distances from the fixing screw holes 202 to the axis of the installation hole are equal, and the lines connecting the adjacent fixing screw holes 202 form a square structure, the first extension 101 on each deflection pole piece 11 is spliced into a ring structure in the vertical direction, and the outer diameter of the ring structure of the deflection pole piece 11 is smaller than the outer diameter of the ring structure of the second extension 201, the upper surface of the first extension 101 is provided with a pressure line hole 104, and the side wall is provided with a wire inlet hole 105, the side wall of the second extension 201 is clamped by using a clamping device, and the side wall of the insulating mounting seat 20 without the second extension 201, the lower surface of the second extension 201 and the inner wall of the optical axis hole 102 of the initial type of the deflection plate 10 are sequentially finished.

[0048] In this implementation, the side wall of the second extension 201 is used as the clamping surface, the upper surface of the deflection plate 10 prototype is leveled, and then the side wall of the insulating mounting seat without the second extension 201, the lower surface of the second extension 201, and the inner wall of the optical axis hole 102 of the deflection plate 10 prototype are sequentially processed. This processing sequence ensures the perpendicularity of the side wall of the deflection plate 10 without the first extension 101 and the side wall of the insulating mounting seat 20 without the second extension 201, thereby ensuring that the geometric center of the electrostatic field of the deflection plate 10 after installation is as possible as possible perpendicular to the electron beam, so that the deflector prepared by the electrostatic deflector processing method of the present application is suitable for higher process production lines.

[0049] In a possible implementation, the deflection plate 10 prototype is cut along the cutting line 103 using a slow wire, and is cut into eight-petal average deflection plate blocks 11.

[0050] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical application, or improvement of the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. An electrostatic field deflector adapted for mounting within a scanning electron microscope, characterised in that, The deflection electrode plate and the insulating mounting base are included. The middle part of the insulating mounting base has a mounting hole. The deflection electrode plate is a cylinder as a whole, and the outer sidewall of the deflection electrode plate is matched with the mounting hole. The deflection electrode plate is evenly divided into an even number of deflection electrode blocks along the radial direction. The upper sidewall of the deflection electrode block extends out of the insulating mounting base and outwardly extends a first extension part, the upper surface of the first extension part is lower than the upper surface of the deflection electrode block, and the lower surface of the first extension part is in contact with the upper surface of the insulating mounting base. The deflection electrode plate is a cylinder, and the sidewall surface of the deflection electrode plate without the first extension part is provided with a groove in contact with the inner wall of the mounting hole. The upper sidewall of the insulating mounting base outwardly extends a second extension part, the second extension part has a ring structure in the vertical direction, four fixing screw holes are formed in the second extension part, the axial distance from the fixing screw holes to the mounting hole is equal, and the connecting lines of adjacent fixing screw holes form a square structure. The upper surface of the first extension part is provided with a pressing line hole, and the sidewall is provided with a wire inlet hole.

2. The electrostatic deflector of claim 1, wherein The deflection electrode plate is divided into eight deflection electrode blocks.

3. The electrostatic deflector of claim 2, wherein The material of the deflection electrode plate is beryllium copper, and the material of the insulating mounting base is ceramic.

4. A method of processing an electrostatic field deflector, the electrostatic field deflector being processed according to claim 1, characterized by The upper sidewall of the deflection electrode block extends out of the insulating mounting base and outwardly extends a first extension part, the upper surface of the first extension part is lower than the upper surface of the deflection electrode block, and the lower surface of the first extension part is in contact with the upper surface of the insulating mounting base. The deflection electrode plate is a cylinder, and the sidewall surface of the deflection electrode plate without the first extension part is provided with a groove in contact with the inner wall of the mounting hole. The method comprises the following steps: rough machining the deflection electrode plate to be processed to form a deflection electrode plate initial type with a first extension part in the upper sidewall and a groove in the sidewall without the first extension part; Rough machining the insulating mounting base to be processed to form a mounting base initial type with a mounting hole in the middle part; Coating an adhesive in the groove of the deflection electrode plate and / or the inner wall of the mounting hole of the insulating mounting base, and waiting for a preset time after the deflection electrode plate and the insulating mounting base are adhesively fixed to release the adhesive stress; The preliminary machining of the deflection electrode plate to be processed further comprises: placing the deflection electrode plate to be processed on a cutting line machining device to process an even number of cutting lines in the radial direction on the upper surface, the side surface and the lower surface of the deflection electrode plate to be processed; Cutting the deflection electrode plate initial type into eight deflection electrode blocks using a slow wire.

5. A method of processing an electrostatic deflector as claimed in claim 4, characterized in that The upper side wall of the insulating mounting seat extends outwardly with a second extension part, which is annular in vertical direction, and four fixing screw holes are formed in the second extension part, the axial distance of the fixing screw holes to the mounting hole is equal, and the connecting line of adjacent fixing screw holes forms a square structure; The first extension part on each deflection pole block is annular in vertical direction, and the outer diameter of the annular structure of the deflection pole block is smaller than that of the second extension part; The upper surface of the first extension part is provided with a pressing wire hole, and the side wall is provided with a wire inlet hole; The side wall of the second extension part is clamped by a clamping device, and the side wall of the insulating mounting seat without the second extension part, the lower surface of the second extension part and the inner wall of the optical axis hole of the deflection pole plate are sequentially finished.

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