JP2005032574A - Plate-like coil, toroidal coil structure, and charged particle beam exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate-like coil where coils can be easily aligned with high accuracy, when assembling a coil structure. <P>SOLUTION: A toroidal coil assembly comprises a cylindrical member having a plurality of grooves, extending in its longitudinal direction on the outer surface; and a plate-like member which is fitted into the cylindrical member so that at least one surface becomes perpendicular with respect to the axial direction of the cylindrical member, and has a plurality of grooves extending radially around the intersection with the axis of the cylindrical member. The plate-like coil which is inserted into the groove in the toroidal coil assembly and arranged radially with respect to the axis of the toroidal coil assembly, is characterised by being provided with a board member where the coils are formed on both sides; and positioning protrusions which are formed on at least one side of this board member and adjust the relative position, in between the cylindrical member or the plate-like member and the coils, by abutting shoulders of the grooves of the cylindrical member or the plate-like member, when inserted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coil substrate of a coil structure used for a deflector and an astigmatism corrector of a charged particle beam exposure apparatus, and in particular, a coil substrate capable of easily and highly accurately aligning a coil when the coil structure is assembled. About.

In recent years, the degree of integration of semiconductor integrated circuits has been increasing, and research and development of charged particle beam exposure apparatuses capable of producing finer semiconductor integrated circuits have been actively conducted. Among them, an electron beam exposure apparatus that draws a circuit pattern called a reticle on a wafer by a projection lens of an electron optical system has attracted attention.
The reticle is made of, for example, a silicon wafer having a diameter of about 200 mm. However, since the exposure field of the electron beam exposure apparatus is as small as about 250 μm, the subdivided pattern is connected to expose a chip of several tens of mm square. While exposing. Patent Document 1 discloses a technique for repeating exposure while deflecting an electron beam as means for joining patterns. In any electron beam exposure apparatus, it is indispensable to deflect an electron beam in any electron beam exposure apparatus, and without this technique, an electron beam exposure apparatus cannot be realized. Accordingly, every electron beam exposure apparatus includes a deflector, an astigmatism corrector for correcting astigmatism, and the like, which is one of important components.

These deflectors and astigmatism correctors have been devised in various structures, and one of them is called a toroidal coil. In this toroidal coil, in order to make the magnetic flux of the coil uniform, the position of the coil is required to have a positioning accuracy of about ± 50 μm at each location.
Patent Document 2 discloses a technique related to improvement of the mounting position accuracy of the coil substrate (plate coil) of the toroidal coil. The toroidal type coil of Patent Document 2 is formed by forming a coil on a plate-like coil and arranging the plate-like coils radially. The plate coil is fitted in a groove formed on the outer periphery of the cylindrical member and a groove formed on a plane perpendicular to the axis of the cylindrical member in the plate member fitted in the cylindrical member. The plate-like coil is positioned and fixed by bringing the end of the plate-like coil into contact with the groove bottom.

Patent Document 3 discloses a toroidal coil structure by the present inventor. For quartz, machinable ceramics, fine ceramics, etc., it is difficult to align the groove depth that affects the accuracy of the mounting position of the plate coil. It is designed for easy and accurate installation.
US Pat. No. 4,376,249 US Pat. No. 6,153,885 Japanese Patent Application Laid-Open No. 2003-74526

  Here, the positional accuracy of the coil in the coil structure is greatly influenced by the position of the coil from the outer periphery of the plate coil rather than the mounting position of the plate coil. Therefore, in an actual manufacturing process, it is necessary to correct the coil position of each plate coil after forming a copper coil by lithography on the plate material and cutting the plate coil by laser processing or the like. However, it is difficult to align the distance from the coil position to the outer periphery of the plate coil with an accuracy of about ± 50 μm by laser processing or the like, and there is room for improvement in this respect.

In addition, in the case of incorporating a plurality of types of plate-like coils in the conventional toroidal coil, it is difficult to ensure the positional accuracy of the coil because the shape of the coil is different for each coil substrate. there were.
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a plate coil that can easily and accurately align a coil during assembly of a coil structure. .

  The invention according to claim 1 is fitted to the cylindrical member having a plurality of grooves extending in the length direction on the outer peripheral surface, and the cylindrical member so that at least one surface is perpendicular to the axial direction of the cylindrical member, Inserted in the groove in the toroidal coil assembly comprising a plate-like member having a plurality of grooves extending radially about the intersection with the axis of the cylindrical member, and arranged radially with respect to the axis of the toroidal coil assembly In the plate-like coil, the plate member formed on both sides of the coil and the plate member is formed on at least one side of the plate member, and contacts the cylindrical member or the shoulder of the groove of the plate-like member during the insertion. A positioning projection for adjusting a relative position between the member or the plate-like member and the coil is provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the coil and the positioning protrusion are simultaneously formed by lithography.
According to a third aspect of the present invention, in the first or second aspect of the present invention, an outer edge portion of the coil formed on the plate member serves as the positioning protrusion.
According to a fourth aspect of the present invention, a cylindrical member having a plurality of grooves extending in the length direction on an outer peripheral surface, and the cylindrical member are fitted to the cylindrical member so that at least one surface is perpendicular to the axial direction of the cylindrical member, The toroidal type coil assembly which consists of a plate-shaped member which has several groove | channels radially extended centering | focusing on the intersection with the axis | shaft of a cylindrical member, The plate-shaped coil of any one of Claims 1-3 A toroidal type coil structure, wherein the plate-like coil is inserted into the groove of the cylindrical member and the plate-like member, and the plate-like coil is arranged with respect to the axis of the toroidal-type coil assembly. The plate-like coil positioning projections are arranged in a radial manner and contact the shoulder of the groove of the cylindrical member or the plate-like member, and the relative position between the cylindrical member or the plate-like member and the coil is adjusted. Specially To.

  According to a fifth aspect of the present invention, there is provided a charged particle beam exposure apparatus comprising the toroidal type coil structure according to the fourth aspect.

In the plate coil of the present invention, the relative position of the plate coil and the toroidal coil assembly is adjusted by the positioning protrusion. Therefore, the plate coil can be easily and highly accurately attached to the toroidal coil assembly without being affected by the cutting accuracy of the plate coil.
Moreover, in the coil structure and the charged particle apparatus of the present invention, a highly accurate toroidal coil structure and a charged particle beam exposure apparatus using the same can be obtained by using the plate coil.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
1 to 5 are views showing a plate-like coil 1 according to the first embodiment and a toroidal type coil structure using the plate-like coil 1 (corresponding to claims 1, 2 and 4). To do). The plate-like coil 1 according to the first embodiment constitutes a toroidal type coil structure 11 together with a toroidal type coil assembly 10.
(Configuration of toroidal coil assembly)
First, the configuration of the toroidal coil assembly 10 into which the plate coil 1 is inserted will be described. The toroidal coil assembly 10 includes a cylindrical member 12 and a plate-like member 13.

A plurality of grooves 14 are formed on the outer peripheral surface of the cylindrical member 12 so as to extend in the length direction of the cylindrical member 12.
Further, the plate-like member 13 is a member formed in a donut shape, and is fitted into the cylindrical member 12 on the inner periphery thereof. A plurality of grooves 15 radiating from the center of the plate-like member 13 are formed on one surface of the plate-like member 13.

In the assembly of the toroidal coil assembly 10, the cylindrical member 12 is fitted to the inner periphery of the plate-like member 13 so that the formation surface of the groove 15 of the plate-like member 13 is perpendicular to the axial direction of the cylindrical member 12, Fix with adhesive. At this time, the position of the groove 14 of the cylindrical member 12 and the position of the groove 15 of the plate-like member 13 are made to correspond to each other.
(Configuration of plate coil)
Next, the configuration of the plate coil 1 of the first embodiment will be described. The plate coil 1 is composed of a plate member 2, a coil 3, and a positioning projection 4. The plate-like coil 1 is inserted into the groove 14 and the groove 15 of the toroidal coil assembly 10 and is arranged radially about the axis of the toroidal coil assembly 10.

The plate member 2 is formed of an insulator such as quartz, machinable ceramics, or fine ceramics. The thickness of the plate member 2 is set slightly smaller than the groove widths of the groove 14 and the groove 15 of the toroidal coil assembly 10 so that the plate member 2 can be inserted into the groove 14 and the groove 15.
The coil 3 is formed on both surfaces of the plate member 2. The pattern of the coil 3 has a line-symmetric shape that is right-handed on the front side (or back side) of the plate member 2 and is left-handed on the back side (or front side) of the plate member 2. The coil 3 is formed on both surfaces of the plate member 2 so that the pattern of the coil 3 matches back to back across the plate member 2. The plate member 2 is penetrated at the center of the coil 3, and the coils 3 on both sides are conducted.

  The coil 3 is formed by the following process. First, a thin film conductor is formed on the flat plate member 2 by vapor deposition or the like. This thin film conductor becomes an electrode in the subsequent electroforming process. Next, a thick film resist is applied to both surfaces of the plate member, and then patterned into a predetermined shape by lithography. This thick resist pattern serves to limit the growth direction of electroforming from the substrate to the vertical direction in the subsequent electroforming process. Next, the plate member 2 is immersed in an electroforming solution containing copper, and copper is deposited on the electrodes by electroforming. Thereafter, the thick film resist is removed. Finally, the thin film conductor is removed by etching or the like, and the coil 3 is formed on the plate member 2.

The positioning protrusions 4 are respectively formed on both surfaces of the plate member 2 on which the coil 3 is formed. The positioning protrusions 4 are provided at a total of three locations, two on the boundary between the plate member 2 and the portion inserted into the groove 14 and one on the boundary with the portion inserted into the groove 15.
The positioning protrusion 4 is made of copper like the coil 3 and is formed at the same time as the coil 3 in the above-described process of forming the coil 3. Since the positioning protrusion 4 is formed by lithography, it is easy to stably align the position of the coil and the positioning protrusion with high accuracy of about ± 30 μm. Furthermore, since the coil 3 and the positioning protrusion 4 are formed at a time, the forming operation of the positioning protrusion 4 is not complicated.

The projection height of the positioning projection 4 on both surfaces of the plate member 2 is such that the positioning projection 4 interferes with the shoulder of the groove 14 or the groove 15 in a state where the plate coil 1 is inserted into the toroidal coil assembly 10. It is set to height.
The positioning projection 4 is limited to the arrangement of the first embodiment as long as the relative position between the cylindrical member or plate-like member and the coil can be adjusted and the plate-like coil can be stably supported. is not. For example, as shown in FIG. 3, the positioning protrusion 4 may be formed as a groove or a positioning protrusion on the groove side continuously, or may be appropriately changed such as forming the positioning protrusion in an L shape. Furthermore, the positioning protrusions do not need to be formed so that their positions correspond to both surfaces of the plate member, and the pattern of the positioning protrusions on both surfaces of the plate coil 1 may be asymmetric (not shown).
(Assembly of toroidal coil structure)
The toroidal coil structure 11 includes the plate-like coil 1 inserted into the groove 14 of the cylindrical member 12 and the groove 15 of the plate-like member 13 and fixed with an adhesive or the like. It completes by arrange | positioning radially centering on the axis | shaft of the coil assembly 10. FIG. The toroidal coil structure 11 generates a combined magnetic field in the direction perpendicular to the optical axis on the optical axis by controlling the current flowing through the plate coil 1, and Lorentz by the interaction between the magnetic field and the electron beam. The electron beam is deflected by force.

  In the assembled state of the toroidal coil structure 11, the three positioning projections 4 of the plate coil 1 abut on the shoulders of the groove 14 or the groove 15 of the toroidal coil assembly 10. Therefore, the plate-like coil 1 is stably supported at three points where the positioning protrusion 4 contacts the toroidal coil assembly 10. And the relative position of the coil 3 of the plate-shaped coil 1 arrange | positioned radially by the positioning protrusion 4 on the basis of the surface of the cylindrical member 12 and the plate-shaped member 13 is each adjusted.

In the present invention, the positioning protrusion 4 aligns the position of the coil 3 for the following reason. Conventionally, the coil 3 has been positioned by bringing the peripheral edge of the plate coil 1 into contact with the groove bottom of the toroidal coil assembly 10. However, it is very difficult to align the position from the outer periphery of the plate member 2 to the coil 3 with high accuracy. Therefore, in the present invention, the position of the coil 3 is adjusted by the positioning protrusion 4 with reference to the shoulder portion of the groove 14 or the groove 15 (the surface of the cylindrical member 12 or the plate-like member 13). That is, in the present invention, the positional accuracy of the coil 3 in the toroidal coil structure is not affected by the distance from the outer periphery of the plate member 2 to the coil 3. Therefore, it is not necessary to adjust the distance from the outer periphery of the plate member 2 to the coil 3 after the plate coil 1 is cut by laser processing, and the manufacturing efficiency is greatly improved.
(Second Embodiment)
FIG. 6 is a view showing a plate coil 1a according to a second embodiment of the present invention (corresponding to claims 1 to 3). In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the plate coil 1a of the second embodiment, a coil 3 for deflecting an electron beam and a correction coil 5 are arranged on one plate member 2. The outer periphery of the correction coil 5 is located on the boundary between the insertion portion of the groove 14 and the insertion portion of the groove 15, and the outer edge portion of the correction coil 5 functions as a positioning protrusion. Thereby, the relative position of the coil 3 of the plate-like coil 1 is adjusted by the positioning projection 4 and the outer edge portion of the correction coil 5 with reference to the surfaces of the cylindrical member 12 and the plate-like member 13.

In addition, when assembling a toroidal type coil structure using a plurality of types of plate-like coils as in the first embodiment and the second embodiment, the size of the plate member, the position of the coil, etc. can be matched in the prior art. It becomes difficult. Therefore, in such a case, the alignment of the coil by the positioning protrusion of the present invention is particularly effective.
(Third embodiment)
FIG. 7 is a diagram showing an outline of an electron beam exposure apparatus using the toroidal coil structure 11 of the present invention, which is a third embodiment (corresponding to claim 5).

The electron beam exposure apparatus in FIG. 7 includes an electron gun 20, an illumination optical system 21, a reticle stage 22, projection lenses 23 and 24, and a wafer stage 25.
An electron beam is emitted from the electron gun 20 of the electron beam exposure apparatus, passes through the illumination optical system 21, and is irradiated onto the reticle 26. Among the electron beams that irradiate the surface of the reticle 26, those that have passed the pattern formed on the reticle 26 are reduced and transferred onto the surface of the wafer 27 by the projection lenses 23 and 24. The toroidal type coil structure 11 of the present invention is provided for controllably shifting the activation of the electron beam. In the above description, the toroidal coil structure 11 is used at all locations, but the toroidal coil structure 11 is not necessarily used at all locations. Further, a toroidal coil structure 11 having both functions of a deflector and a magnetic lens may be used. Although the above example relates to the projection optical system, it goes without saying that the toroidal coil structure 11 of the present invention can be used in the illumination optical system as well.

  In the present invention, the relative position between the plate coil and the toroidal coil assembly is adjusted by the positioning protrusion. Therefore, the plate coil can be attached to the toroidal coil assembly easily and with high accuracy without being affected by the cutting accuracy of the plate coil, and a highly accurate toroidal coil structure or charged particle beam exposure apparatus Can provide.

(A) is a front view of the plate-shaped coil of 1st Embodiment, (b) is a front view which shows the state which attached the plate-shaped coil of 1st Embodiment to the toroidal type coil assembly. It is sectional drawing which shows the contact state of the positioning protrusion and toroidal type coil assembly in FIG.1 (b). It is the figure which showed the modification of arrangement | positioning of the positioning protrusion of 1st Embodiment. It is a perspective view which shows the outline | summary of the attachment to the toroidal type coil assembly of a plate-shaped coil. It is a top view of a toroidal type coil structure. (A) is a front view of the plate-shaped coil of 2nd Embodiment, (b) is a front view which shows the state which attached the plate-shaped coil of 2nd Embodiment to the toroidal type coil assembly. It is a schematic diagram of the charged particle beam exposure apparatus of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Plate coil 2 Plate member 3 Coil 4 Positioning protrusion 5 Correction coil 10 Toroidal type coil assembly 11 Toroidal type coil structure 12 Cylindrical member 13 Plate members 14, 15 Groove 20 Electron gun 21 Illumination optical system 22 Reticle stage 23, 24 Projection lens 25 Wafer stage 26 Reticle 27 Wafer 28 Scattering aperture

Claims (5)

A cylindrical member having a plurality of grooves extending in the length direction on the outer peripheral surface, and an intersection of the cylindrical member, which is fitted to the cylindrical member so that at least one surface is perpendicular to the axial direction of the cylindrical member. In the plate-like coil inserted into the groove in the toroidal coil assembly comprising a plate-like member having a plurality of grooves extending radially about the center, and arranged radially with respect to the axis of the toroidal coil assembly,
A plate member having coils formed on both sides;
Positioning that is formed on at least one side of the plate member and adjusts the relative position between the cylindrical member or the plate-like member and the coil by contacting the shoulder of the groove of the cylindrical member or the plate-like member during the insertion. A plate-like coil comprising: a protrusion. The plate coil according to claim 1, wherein the coil and the positioning protrusion are formed simultaneously by lithography. The plate-shaped coil according to claim 1, wherein an outer edge portion of the coil formed on the plate member serves as the positioning protrusion. A cylindrical member having a plurality of grooves extending in the length direction on the outer peripheral surface, and an intersection of the cylindrical member, which is fitted to the cylindrical member so that at least one surface is perpendicular to the axial direction of the cylindrical member. A toroidal type coil assembly comprising a toroidal type coil assembly comprising a plate-like member having a plurality of grooves extending radially from the center and the plate-like coil according to any one of claims 1 to 3. A structure,
The plate-like coil is inserted into the cylindrical member and the groove of the plate-like member, and the plate-like coil is arranged radially with respect to the axis of the toroidal type coil assembly,
The positioning projection of the plate-like coil is in contact with the shoulder of the groove of the cylindrical member or the plate-like member, and the relative position between the cylindrical member or the plate-like member and the coil is adjusted. Toroidal coil structure. A charged particle beam exposure apparatus comprising the toroidal coil structure according to claim 4.

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