JP2006185637A - Electrostatic deflector and electron beam device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic deflector and an electron beam device in which adjustment is not needed in assembling and disassembling, and in which repeated and highly precise positioning precision is enabled. <P>SOLUTION: In the electrostatic deflector 1 which is composed of a non-magnetic conductor and a cylindrical supporting body 5 wherein a plurality of recessed grooves 4 opened at the center axis side along the longitudinal direction are formed with an equal spacing, and which is composed a plurality of electrode pieces 6 that are arranged in the recessed grooves 4 and where a conductive film is formed on the center axis side surface, side walls 4a of the recessed grooves 4 are slanted, and the electrode pieces 6 have slanted parts 6a matching with the side walls 4a of the recessed grooves 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrostatic deflector such as a lens or an aperture in an electron optical system used in an electron beam apparatus, and more particularly to an electrostatic deflector that can hold an optical element of the electron optical system arranged in the electron beam apparatus with high positioning accuracy. The present invention relates to a deflector and an electron beam apparatus using the deflector.

  In general, an electron beam apparatus includes an electron gun that emits an electron beam, a primary electron optical system that includes an electrostatic deflector that focuses the electron beam from the electron gun and irradiates the sample, and secondary electrons from the sample. Are provided with a secondary electron optical system that makes the light incident on the detector, a device for detecting secondary electrons, and the like.

  Conventionally, the electrostatic deflector is formed with a plurality of electrode portions along the longitudinal direction on the inner periphery, and the surface of the electrode portions is processed with high accuracy roundness and coaxiality. In order to process the electrode with high accuracy, the electrostatic deflector inserts a plurality of high-precision finished optical elements individually into a cylindrical part that has been processed with high-precision fitting tolerance. By stacking themselves one by one and stacking them while adjusting each stage, the respective optical elements are positioned with high accuracy to form a long electrostatic deflector.

  However, it is difficult to achieve the required accuracy with the current machining accuracy by the method that relies on the machining accuracy as described above, and if the fitting tolerance is tightened, even if a slight machining error is required, it is possible to optically It was difficult to assemble the elements and remove the optical elements from the cylindrical member. In addition to the above method, a method is also conceivable in which the fitting tolerance between the cylindrical member and the optical element is loosened so that positioning adjustment from the radial direction can be performed at the time of assembly. However, such adjustment takes time and effort. It is inefficient and takes a lot of effort and time to do with each individual optical element. Even if the accuracy can be maintained, it is very difficult to reproduce the accuracy before disassembly when reassembly is performed after disassembly when maintenance is required.

  On the other hand, in recent years, for example, when forming a circuit by irradiating a silicon wafer with an electron beam, an electron beam apparatus that controls the drawing accuracy with high precision as the lines drawn on the silicon wafer become increasingly finer. Is now required.

  Therefore, extremely high accuracy is required for the positioning accuracy between the optical elements provided in the electron beam apparatus. However, the method that relies on the machining accuracy as described above has a problem that it is difficult to achieve the required accuracy with the current machining accuracy. In addition, when fitting tolerances are tightened, it is difficult to assemble an optical element to a cylindrical member or remove an optical element from the cylindrical member even with a slight processing error.

Therefore, as a method for solving these problems, Patent Document 1 discloses that a cylindrical body that stores a plurality of optical elements is divided into three parts at equal intervals in the circumferential direction, and is provided in a cage that holds each division point. After holding the optical element before processing by three bolts, the optical axis of the optical element is processed, and after marking the optical element, the optical element is removed from the cylinder and post-processing such as electrode formation is performed. Thereafter, an optical element assembling method is proposed in which the optical element is inserted into the cylindrical holder again and fine adjustment is performed at three points.
JP 2002-341216 A

  However, as described above, in order to process with high precision roundness and coaxiality, the positioning of a general optical element is performed by inserting it into a part processed with high precision fitting tolerance, and Since the workers are assembled in a stacked manner while checking the accuracy one by one, the positioning of each optical element requires an assembling technique by an expert and takes time for assembly.

  On the other hand, when trying to increase the positioning accuracy, it is necessary to further tighten the tolerance of high precision, but if the tolerance of tightness is tightened, there is a problem that biting occurs during assembly or disassembly work. . Moreover, if it is a metal or resin cylinder or an optical element, there has been a concern about deformation during assembly.

  Furthermore, in recent years, an object to be evaluated is highly miniaturized, and thus an apparatus having an increasingly higher detection accuracy is required. The method of assembling was desired.

  According to the assembling method of the optical element as described in Patent Document 1, since the optical element is held, and after the optical axis processing, the optical element is incorporated into the cylinder again, the work becomes complicated. There is a problem that accuracy is not obtained because fine adjustment is performed in terms of points. In addition, there is a problem that it is very difficult to form an independent electrode portion with a metal film or the like on the inner peripheral surface of the optical element.

  The present invention has been devised in view of the above-described problems, and an optical element assembly for an electron beam apparatus capable of realizing high positioning accuracy among a plurality of optical elements in an electron optical system with a simple configuration. And an assembly method thereof.

  Another object of the present invention is to provide an electron beam apparatus having good drawing accuracy and detection accuracy provided with the optical element assembly as described above.

  Therefore, in view of the above problems, the inventor of the present invention is an electrostatic deflector according to the present invention, which is made of a nonmagnetic conductor in which a plurality of concave grooves that open toward the central axis along the longitudinal direction of the inner peripheral surface are formed at equal intervals. An electrostatic deflector comprising: a cylindrical support comprising: a conductive film formed on a surface thereof; and an electrode piece disposed in each of the plurality of concave grooves so that the electrode film faces the central axis. The groove side wall is formed in an inclined shape, and an inclined portion that matches the side wall of the concave groove is formed on the side wall of the electrode piece.

  The electrostatic deflector according to the present invention is characterized in that an opening area of the concave groove is larger than an area of the bottom portion.

  Furthermore, the electrostatic deflector of the present invention is characterized in that a minute gap is provided between the bottom of the concave groove and the electrode piece.

  Furthermore, the electrostatic deflector of the present invention is characterized in that the electrode piece is formed by forming a base made of an alumina sintered body and a conductive film on the surface of the base.

  The electron beam apparatus of the present invention is characterized by using the electrostatic deflector.

  According to the configuration of the present invention, the side wall of the concave groove is formed in an inclined shape, and the inclined portion that matches the side wall of the concave groove is formed on the side wall of the electrode piece. And can be assembled with high accuracy even after repeated disassembly and assembly. In particular, it is possible to provide an electrostatic deflector that can maintain the positioning accuracy of a plurality of electrodes with high accuracy and can be realized with a simple configuration.

  In addition, by positioning the plurality of electrodes easily, stable reassembly and disassembly can be realized even when reassembly is performed after disassembly for reasons such as the need for maintenance. Even if not, the operation can be facilitated.

  In addition, since the electrode piece has a substrate made of an alumina sintered body, it is not deformed even during assembly or disassembly, there is little deterioration in accuracy due to wear, and even when heat is applied, the amount of deformation can be kept small. A possible electrostatic deflector can be provided.

  Moreover, the opening area of the said recessed part is larger than the bottom part of the said recessed groove, and the said electrode piece is pressed in the direction which goes to the said outer peripheral side, Therefore A load is applied to an outer peripheral direction in the case of an inner peripheral process Therefore, the processing accuracy can be improved.

  Furthermore, by providing a minute gap between the bottom of the concave groove and the electrode piece, the concave groove side wall of the support and the inclined portion of the electrode piece can surely come into contact with each other.

  Further, by providing an electron beam apparatus provided with such an electrostatic deflector, it is possible to provide an electron beam apparatus that has good drawing accuracy and detection accuracy, and is highly accurate and inexpensive.

  Hereinafter, the best mode for carrying out the present invention will be described.

  1 and 2 are diagrams showing an embodiment of an electrostatic deflector according to the present invention, in which FIG. 1 (a) shows a perspective view, FIG. 1 (b) shows an exploded perspective view, and FIG. ) Is a top view, and FIG. 2B is a cross-sectional view taken along line XX in FIG.

  As shown in FIGS. 1 and 2, the electrostatic deflector 1 of the present invention is made of a nonmagnetic conductor, and a plurality of concave grooves 4 that are open toward the central axis A along the longitudinal direction are formed at equal intervals. A cylindrical support 5 and a plurality of electrode pieces 6 arranged in the groove 4.

  The support 5 is a cylindrical body having a circular shape, a polygonal shape, etc., and considering the workability, a circular shape as shown in FIG. 1 is preferable, and the support 5 is processed with high accuracy by cylindrical grinding or honing. Is possible.

  Further, the support 5 may be a non-magnetic conductor, and is preferably made of carbide or titanium alloy that can be subjected to electric discharge machining since a complicated shape is machined. Furthermore, it is more preferable to use a cemented carbide that does not deform during assembly or disassembly and that has little deterioration in accuracy due to wear.

  The electrode piece 6 includes a nonmagnetic ceramic substrate 9 made of any one of an alumina sintered body, a zirconia sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and the like, and the substrate A conductive film 7 made of a nonmagnetic metal film made of one or more metals such as Cu, Ni, Au, Pt, Ag, TiN, TiC, or the like is formed on the surface 9 on the central axis A side.

  The substrate 9 may be made of ceramic such as non-magnetic, insulating alumina sintered body, zirconia sintered body, silicon carbide sintered body, silicon nitride sintered body, and aluminum nitride sintered body. Preferably, there is no deformation during assembly or disassembly, there is little deterioration in accuracy due to wear, and even when heat is applied, the amount of deformation can be kept small.

  Moreover, since the electrode piece 6 acts as an electrode of the electrostatic deflector 1, it is desirable that two or more even numbers are formed coaxially with the central axis A and on the same circumference, and their areas are substantially equal. .

  Here, in the present invention, it is important that the side wall 4 a of the concave groove 4 is formed in an inclined shape and that the side wall of the electrode piece 6 has an inclined portion 6 a that matches the side wall 4 a of the concave groove 4. .

  Thereby, it can slide in a state without a gap between the side wall 4a of the concave groove 4 and the inclined portion 6a of the electrode piece 6, and can be received by the surface. For this reason, it is possible to perform positioning at the same position every time even if repeated assembly or disassembly work is performed.

  As shown in FIGS. 1 and 2, it is preferable that the opening area K of the groove 4 is inclined so as to be larger than the area S of the bottom.

  As a result, the electrode piece 6 is pressed toward the outer peripheral side and is easily fixed, and positioning is performed in a state where the electrode piece 6 is pressed against the side wall 4a of the concave groove 4 of the support 5, so that assembly and disassembly can be performed. Even if it repeats, it becomes possible to provide the electrostatic deflector 1 which maintained the same precision each time.

  As a method of pressing and fixing the electrode piece 6, as shown in FIG. 1 (b), a female screw portion is formed on the electrode piece 6, and the support member 5 is located at a position where it is mated with the female screw portion. A through hole may be formed, and pulled from the outer peripheral direction of the support 5 by a male screw 10 such as a bolt to the outer peripheral side and fixed so that the side surface of the electrode piece 6 is pressed against the side wall 4 a of the concave groove 4.

  Furthermore, it is preferable that the opening area K of the groove 4 is larger than the area S of the bottom, and the angle of the side wall 4a of the groove 4 and the inclined portion 6a of the electrode piece 6 is preferably 3 to 45 degrees. It should be done. These angles may be determined in consideration of the wall thickness depending on the arrangement of the electrode pieces 6, and the area is determined by the outer diameter of the support 5 and the angle of the inclined surface. By the way, when the angle is smaller than 3 degrees, it is difficult to obtain a gap between the inclined portion 6a and the side wall 4a during assembly or disassembly. On the other hand, when the angle is larger than 45 degrees, the electrode piece 6 is extremely tapered on the outer diameter side and the strength is deteriorated. Further, when the electrode pieces 6 are composed of 6 or more, they interfere with the adjacent electrode pieces 6, and therefore a preferable angle is in the range of 3 to 45 degrees. Although it is preferable to increase the opening area, in the case of increasing the opening area, the adjacent electrode pieces 6 may be formed to have an area where the thickness of the side wall 4a of the concave groove 4 does not become too thin due to interference. As a guide, the side wall 4a may be formed to have a thickness of 0.5 mm or more, preferably 1 mm or more. What is necessary is just to ensure the thickness of the side wall 4a and to enlarge an area.

  Further, as shown in FIG. 1, it may be formed in a straight shape halfway, and only the back side is inclined.

  Further, it is preferable that a minute gap 8 is provided between the bottom 4 b of the groove 4 and the electrode piece 6.

These minute gaps 8 are necessary at the time of assembling, and when assembling is performed without these minute gaps, problems such as the electrode piece 6 biting in the middle are likely to occur. However, if the minute gap 8 is provided, the electrode piece 6 is inserted into the support 5 while minimizing the minute gap 8 during assembly or disassembly, and if the electrode piece 6 is pressed after insertion to the back, the taper portion Thus, a gap is generated and biting can be prevented.

  Further, after the electrode piece 6 is attached to the support 5, it is important that the substantially inner diameter of the electrode piece 6 is processed with a highly accurate cylindricity, regardless of the size of the electrostatic deflector 1. The cylindricity of the inner diameter is preferably finished at 2 μm or less. Further, the angle between the inclined portion 6a of the electrode piece 6 and the side wall 4a of the groove 4 needs to be finished at the same level with almost no gap.

  3 and 4 are diagrams showing another embodiment of the electrostatic deflector according to the present invention, in which FIG. 3 (a) shows a perspective view and FIG. 3 (b) shows an exploded perspective view. 4A is a top view, and FIG. 4B is a sectional view taken along line XX of FIG. 4A.

  3 and FIG. 4, the opening area K of the groove 4 is inclined so as to be smaller than the area S of the bottom. In this case, the electrode piece 6 is pressed in the direction of the central axis A. What is necessary is just to press and fix the electrode piece 6 with a volt | bolt etc. from the outer peripheral direction of the support body 5 so that a female screw part may be penetrated and formed in the outer peripheral part of the support body 5. Further, since the electrode piece 6 is positioned in a state where it is pressed against the side wall 4a of the support body 5, it is possible to provide the electrostatic deflector 1 that maintains the same accuracy every time even if assembly and disassembly are repeated. Become. At this time, since the pressing direction is one direction, no adjustment is required. However, in order to apply grinding resistance to the outer peripheral side when finishing the inner periphery of the electrostatic deflector, as shown in FIGS. It is preferable to incline so that it may become larger than the area S.

Next, a ceramic manufacturing method for forming the base 9 of the electrode piece 6 will be described. For example, as an alumina sintered body, alumina (Al ₂ O ₃ ) 99 to 99.9% by mass, silica (SiO ₂ ), magnesia (MgO), and calcia (CaO) as a sintering aid in total After adding 0.1 to 1% by mass and forming into a desired shape, it is fired at a temperature of 1500 to 1800 ° C. in an air atmosphere or a vacuum atmosphere, or alumina (Al ₂ O ₃ ) 92 to 99. 1-7% by mass of zirconia stabilized or partially stabilized by a stabilizer such as yttria (Y ₂ O ₃ ), magnesia (MgO), calcia (CaO), ceria (CeO ₂ ) is added to mass%. And after shape | molding in a desired shape, what was baked at the temperature of 1500-1700 degreeC in air | atmosphere atmosphere, hydrogen atmosphere, or nitrogen atmosphere is good.

As the zirconia sintered body, zirconia (ZrO ₂ ) partially stabilized with _{3 to} 9 mol% yttria (Y ₂ O ₃ ), or zirconia partially stabilized with 16 to 26 mol% magnesia (MgO) ( ZrO _2), or 8～12Mol% of calcia (CaO) in partially stabilized zirconia (ZrO ₂₎ and 8～16Mol% of ceria (zirconia partially stabilized with CeO ₂₎ a (ZrO ₂₎ into a desired shape What is necessary is just to use what was baked at the temperature of 1400-1700 degreeC in air | atmosphere atmosphere or a vacuum atmosphere after shaping | molding.

Moreover, when using a silicon carbide based sintered body, a total of 10% by mass to 1% by mass of B and C, or Al ₂ O ₃ and Y ₂ O ₃ as sintering aids with respect to 90% by mass to 99% by mass of SiC. After being added into a desired shape, it may be fired at a temperature of 1900 ° C. to 2100 ° C. in an inert gas atmosphere or a vacuum atmosphere. Further, as the sintering aid for B and C, as a carbon component, in addition to carbon black, graphite, etc., a phenol resin that can generate carbon by thermal decomposition, coal tar pitch, or the like can be used. Further, examples of the boron component include B ₄ C and metallic boron. The addition amount of these sintering aids depends on the amount of oxygen in the raw material powder, and requires 1 to 5 moles of carbon and 0.15 to 3 moles of boron for each mole of oxygen in the silicon carbide raw material. However, it is desirable to add an amount of about 1 to 3% by mass of carbon and 0.20 to 1.5% by mass of boron. As the silicon nitride sintered body, Si ₃ N ₄ 96 mass After adding 2 to 4% by mass in total of Al ₂ O ₃ and Y ₂ O ₃ as sintering aids to a% to 98% by mass, the desired shape is formed, and then in a nitrogen atmosphere or vacuum What is necessary is just to use what was baked at the temperature of 1800 degreeC-2000 degreeC in atmosphere or an inert atmosphere.

  Next, the manufacturing method of the support body 5 is demonstrated.

  If the support 5 is, for example, a titanium alloy, an alloy containing 0.5 mass% or less of Fe, N0.07 mass% or less, O0.40 mass% or less, or H0.015 mass% or less is used as a content other than Ti. If it is cemented carbide, it may be non-magnetic cemented carbide and is manufactured by electric discharge machining.

  The electrostatic polarizer 1 manufactured in this way is effectively used as an electron beam apparatus 20 as outlined in FIG.

  The electron beam apparatus 20 includes an electron gun 100 disposed on the electrostatic deflector 1 described above, and a workpiece base plate 101 disposed on the lower side. By using the plurality of electrostatic deflectors 1 with high accuracy as described above, the optical axis is adjusted when the electron beam is irradiated from the electron gun 100 and passes through the inside of the electrostatic deflector 1. Since the position irradiated with the electron beam can be finely adjusted, the workpiece on the workpiece base plate 101 has good drawing accuracy.

  When used in the arrangement shown in FIG. 5, an electron beam apparatus 20 having higher detection accuracy and capable of maintaining the accuracy even when repeated disassembly or assembly for maintenance or the like is obtained. It is done.

  Such an electron beam apparatus has good drawing accuracy and detection accuracy, and can provide a highly accurate and inexpensive electron beam apparatus.

  Next, examples of the present invention will be described.

  A cylindrical body made of a nonmagnetic cemented carbide having a shape as shown in FIG. 1 and FIG. 2 and having an outer diameter of 40 mm, an overall length of 130 mm, and four inner diameter tapered grooves, and a cross-sectional shape of almost Four electrode pieces made of alumina having a total length of 130 mm, in which a convex taper having the same shape as the tapered portion of the cylindrical body is formed on a part of a 5 mm and 13 mm rectangle, and plated with gold on the opposite side of the tapered portion in the cross section. One piece was prepared and the electrostatic deflector 1 was assembled.

  The electrode piece 6 was inserted into the support 5 so that the tapered portion of the same shape was in contact with the support member 5 and fixed using the male screw 10 so that the tapered portion was pressed without a gap.

  Since the electrostatic deflector 1 is similarly machined with high accuracy, the electrostatic deflector 1 having the same cylindricity can be obtained every time even when assembly and disassembly are repeated.

  The present invention can be used for an electrostatic deflector that holds a lens or the like in an electron optical system of an electron beam apparatus, and an electron beam apparatus using the electrostatic deflector.

It is a figure which shows one Example of the electrostatic deflector which concerns on this invention, (a) is a perspective view, (b) has each shown the disassembled perspective view. It is a figure which shows one Example of the electrostatic deflector which concerns on this invention, (a) is a top view, (b) has shown sectional drawing of the cross section in the XX line of the same figure (a), respectively. . It is a figure which shows one Example of the electrostatic deflector which concerns on this invention, (a) is a perspective view, (b) has each shown the disassembled perspective view. It is a figure which shows one Example of the electrostatic deflector which concerns on this invention, (a) is a top view, (b) has shown sectional drawing of the cross section in the XX line of the same figure (a), respectively. . It is the schematic which shows the electron beam apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrostatic deflector 4 ... Concave groove 4a ... Side wall 5 ... Support body 6 ... Electrode piece 6a .... Inclined part 7 ... Conductive film 8 ... Minute clearance 9 ... .... Base 10 ... Male screw 20 ... Electron beam device 100 ... Electron gun 101 ... Base plate for workpiece

Claims (5)

A cylindrical support made of a non-magnetic conductor in which a plurality of concave grooves opened toward the central axis along the longitudinal direction of the inner peripheral surface are formed at equal intervals; and a conductive film formed on the surface, the electrode film In the electrostatic deflector comprising the electrode pieces respectively disposed in the plurality of grooves so as to face the central axis, the side walls of the grooves are formed in an inclined shape, and the side walls of the electrode pieces are An electrostatic deflector characterized in that an inclined portion that matches the side wall of the groove is formed. 2. The electrostatic deflector according to claim 1, wherein the opening area of the concave groove is larger than the area of the bottom. The electrostatic deflector according to claim 1, wherein a minute gap is provided between the bottom of the concave groove and the electrode piece. The electrostatic deflector according to claim 1, wherein the electrode piece is formed by forming a base made of an alumina sintered body and a conductive film on a surface of the base. An electron beam apparatus using the electrostatic deflector according to claim 1.

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