Electron gun cathode mechanism and method for manufacturing the same

Abstract

PURPOSE: To provide a cathode mechanism with which it is possible to extend the life of a cathode with which a desired luminance distribution is obtained.CONSTITUTION: The cathode mechanism of an electron gun comprises: a crystal 10 having an upper part of a columnar or truncated cone shape or a combination of these having a first face that emits thermoelectrons upon heating, and a lower part having a second face which is substantially parallel to the first face and larger in diameter size than the maximum diameter size of the upper part and being constructed integrally with the upper part; a holding part 12 which is formed in cylindrical form having a plurality of different inner diameters from the upper face side, including a first diameter size and a second diameter size larger than the first diameter size, and which holds the crystal in such a state that the first face of the crystal protrudes from the upper face and is in contact with the second face of the crystal in the cylinder; and a hold-down part 13 for holding down the crystal on the lower reverse side of the crystal so as not to come off from the holding part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] One aspect of the invention relates to an electron gun cathode assembly and a method for manufacturing an electron gun cathode assembly. [Background technology]

[0002] Lithography technology, which is responsible for the advancement of miniaturization of semiconductor devices, is the only extremely important process in the semiconductor manufacturing process that generates patterns. In recent years, with the increasing integration of LSIs, the circuit line width required for semiconductor devices has become finer year by year. Here, electron beam (EB) drawing technology has inherently excellent resolution, and mask patterns are drawn on mask blanks using electron beams.

[0003] For example, there is a lithography device that uses multiple beams. Compared to lithography using a single electron beam, the use of multiple beams allows many beams to be irradiated at once, greatly improving throughput. In such a lithography device using the multi-beam method, for example, an electron beam emitted from an electron gun is passed through a mask with multiple holes to form multiple beams, each of which is blanked and each beam that is not blocked is reduced in size by an optical system, the mask image is reduced in size, and the beams are deflected by a deflector to be irradiated at the desired position on the sample.

[0004] A crystal whose side surface is covered with a coating material up to the same height as the electron emission surface is used as the cathode of a thermionic gun that emits an electron beam (see, for example, Patent Document 1). The crystal wears out with use, and the electron emission surface recedes from its initial state. When a crystal whose side surface is covered with a coating material is used, if the electron emission surface recedes a certain amount from the end surface of the coating material, the desired luminance distribution cannot be obtained, and the cathode reaches the end of its life. When the cathode reaches the end of its life, the device must be stopped each time, and the operating time of the device is shortened. On the other hand, when a crystal whose side surface is not covered is used, electrons are also emitted from the side surface of the crystal, making it difficult to control the desired luminance distribution. Therefore, it is necessary to extend the life of a cathode that can obtain a desired luminance distribution. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Republished Patent No. WO2007 / 055154 Summary of the Invention [Problem to be solved by the invention]

[0006] One aspect of the present invention provides a cathode mechanism and a method for manufacturing the same that can extend the life of the cathode to obtain a desired luminance distribution. [Means for solving the problem]

[0007] The cathode mechanism of an electron gun according to one aspect of the present invention comprises: A crystal having an upper portion having a columnar shape, a truncated cone shape, or a combination thereof, and having a first surface that emits thermoelectrons when heated, and a lower portion having a second surface that is approximately parallel to the first surface and has a diameter larger than the maximum diameter of the upper portion, and being integral with the upper portion; a holding section formed in a cylindrical shape having a plurality of different inner diameters from the top surface side, the first diameter size and a second diameter size larger than the first diameter size, the holding section holding the crystal in a state where the first surface of the crystal protrudes from the top surface and is in contact with the second surface of the crystal within the cylinder; a holding part that holds the crystal on the back side of the lower part of the crystal so that the crystal does not come off the holding part; The present invention is characterized by comprising:

[0008] Also, it is preferable that the amount by which the first surface protrudes from the upper surface of the holding portion is 10% or less of the diameter of the first surface.

[0009] It is also preferable that the holding portion be formed with an opening that has a first diameter size from the top surface to an intermediate height position, or that expands from the top surface to have the first diameter size at an intermediate height position and then has a second diameter size larger than the first diameter size from the intermediate height position toward the back surface side.

[0010] It is also preferable to further include first and second support columns that support the holding portion and that extend while maintaining the same cross-sectional size.

[0011] It is also preferable that the holding portion and the pressing portion are made of the same material.

[0012] A method for manufacturing a cathode mechanism for an electron gun according to one aspect of the present invention includes the steps of: a step of inserting a crystal having a columnar, truncated cone or combination thereof upper part having a first surface that emits thermoelectrons when heated, and a lower part integral with the upper part, the lower part having a second surface that is substantially parallel to the first surface and has a diameter larger than the maximum diameter size of the upper part, into the openings from the back side of a cylindrical holder having a plurality of openings with different inner diameters, the first diameter size and a second diameter size larger than the first diameter size, from the top side; a step of holding the crystal on the back side of the lower part of the crystal with a holding part so that the crystal does not come off the holding part while the first surface protrudes from the end of the opening and the second surface of the crystal is abutted against the surface in the opening where the diameter size changes from the second diameter size to the first diameter size; The present invention is characterized by comprising: Effect of the Invention

[0013] According to one aspect of the present invention, the amount of crystal protruding from the upper surface of the holder can be controlled with high precision, thereby extending the life of the cathode that provides a desired luminance distribution. [Brief description of the drawings]

[0014] [Figure 1] 2 is a cross-sectional view showing an example of the configuration of a cathode mechanism of an electron gun in the first embodiment. [Diagram 2] 2 is a top view showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment. FIG. [Diagram 3] 2 is an enlarged cross-sectional view of an example of a crystal, an example of a holding portion, and an example of a pressing portion in the first embodiment. FIG. [Figure 4]5A to 5C are cross-sectional views for explaining an example of a manufacturing method for the cathode mechanism of the electron gun in the first embodiment. [Diagram 5] 5A to 5C are diagrams illustrating an example of a method for fixing a pressing portion in the first embodiment. [Figure 6] 6A to 6C are diagrams illustrating another example of a method for fixing the holding portion in the first embodiment. [Figure 7] FIG. 11 is a diagram for explaining the life of a cathode in a comparative example of the first embodiment. [Figure 8] FIG. 4 is a diagram for explaining the life of a cathode in the first embodiment. [Figure 9] 4 is a diagram for explaining the relationship between the height position of the electron emission surface of the crystal and the electric field distribution in the first embodiment. FIG. [Figure 10A] 5 is a diagram showing the relationship between the luminance, the cathode temperature, and the emission current and the protrusion amount of the electron emission surface in the first embodiment. FIG. [Figure 10B] 5 is a diagram showing the relationship between the emission current and the protrusion amount of the electron emission surface in the first embodiment. FIG. [Figure 11] 4 is an enlarged cross-sectional view of another example of the crystal, another example of the holding portion, and an example of the pressing portion in the first embodiment. FIG. [Figure 12] 4 is an enlarged cross-sectional view of another example of the crystal, another example of the holding portion, and an example of the pressing portion in the first embodiment. FIG. [Figure 13] 4 is an enlarged cross-sectional view of an example of a crystal, another example of a holding portion, and an example of a pressing portion in the first embodiment. FIG. [Figure 14] 4 is an enlarged cross-sectional view of another example of the crystal, another example of the holding portion, and an example of the pressing portion in the first embodiment. FIG. [Figure 15] 4 is an enlarged cross-sectional view of another example of the crystal, another example of the holding portion, and an example of the pressing portion in the first embodiment. FIG. [Figure 16] FIG. 1 illustrates an example of a configuration of a drawing device according to a first embodiment. [Figure 17] 2 is a conceptual diagram showing a configuration of a shaping aperture array substrate in the first embodiment. FIG. [Figure 18]2 is a cross-sectional view showing a configuration of a blanking aperture array mechanism in the first embodiment. FIG. [Figure 19] FIG. 2 is a conceptual diagram for explaining an example of a drawing operation in the first embodiment. [Figure 20] 3 is a diagram showing an example of a region irradiated with multiple beams and a pixel to be written in the first embodiment. FIG. [Figure 21] FIG. 2 is a diagram for explaining an example of a multi-beam writing method according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In the following embodiments, a configuration using multiple beams as the electron beam will be described. However, the present invention is not limited to this, and a configuration using a single beam may be used. In addition, although a drawing device will be described below, the device may be any device other than a drawing device as long as it uses an electron beam emitted from a thermoelectron emission source. For example, the device may be an image acquisition device, an inspection device, or the like.

[0016] Embodiment 1 FIG. 1 is a cross-sectional view showing an example of the configuration of a cathode mechanism of an electron gun in the first embodiment. FIG. 2 is a top view showing an example of the configuration of the cathode mechanism of the electron gun in the first embodiment. FIG. 3 is an enlarged cross-sectional view of an example of a crystal, an example of a holding portion, and an example of a pressing portion according to the first embodiment. 1 and 2, a cathode mechanism 222 of the electron gun includes a crystal 10, a holder 12, a pressing portion 13, a pair of support columns 14, 16, and a pair of base portions 18, 19. As shown in FIG.

[0017] When the crystal 10 is heated, it emits thermoelectrons from an electron emission surface 11 (first surface) which is one end surface. The material of the crystal 10 is, for example, lanthanum hexaboride (LaB 6 The crystal orientation within the electron emission surface 11 of the crystal 10 is the same. For example, it is preferable that the crystal orientation is (100) or (310).

[0018] As shown in FIG. 3, the crystal 10 is composed of an upper portion 70 and a lower portion 80. The upper portion 70 and the lower portion 80 are integrally formed. The upper portion 70 is formed in a columnar shape, a truncated cone shape, or a combination thereof. Examples of columnar shapes include a circular cylinder, a square prism, or a polygonal prism having more angles than a square. In the example of FIGS. 1 to 3, the upper portion 70 has a diameter φ 1 The upper surface of the upper portion 70 becomes the electron emission surface 11 (first surface). It is desirable for the electron emission surface 11 to be circular.

[0019] The lower portion 80 is configured in a columnar or truncated cone shape. The columnar shape includes, for example, a circular cylinder, a square prism, or a polygonal prism having more sides than a square. Similarly, the columnar shape includes, for example, a circular cylinder, a square prism, or a polygonal prism having more sides than a square. Alternatively, it may be a triangular prism. Alternatively, it may be a combination of a plurality of columns or truncated cones having different maximum diameter sizes. In the example of FIGS. 1 to 3, the lower portion 80 has a diameter φ larger than the maximum diameter size of the upper portion 70. 2 1 shows a case where the lower portion 80 is formed in a cylindrical shape. The lower portion 80 has a seating surface 81 (second surface) with a diameter larger than the maximum diameter size of the upper portion 70. The seating surface 81 becomes the upper surface of the lower portion 80. The seating surface 81 is formed approximately parallel to the electron emission surface 11.

[0020] The holder 12 holds the crystal 10 with the electron emission surface 11 of the crystal 10 exposed and at least a portion of the other surfaces of the crystal 10 covered. The material of the holder 12 can be one of graphite, tantalum, tungsten, and iridium. Specifically, the holder 12 is formed in a cylindrical shape having a plurality of different inner diameters, a small diameter size (first diameter size) from the top side and a diameter size (second diameter size) larger than the small diameter size, and holds the crystal 10 with the electron emission surface 11 of the crystal 10 protruding from the top surface and in contact with the seating surface 81 of the crystal 10 inside the cylinder. The holder 12 has a diameter φ 3 An opening 42 is formed through the center of the cylindrical body. Specifically, the following openings 42 are formed.

[0021] In the holding part 12, an opening 42 is formed which has a size (first diameter size) of the maximum diameter size of the upper part 70 of the crystal 10 + α from the top surface to an intermediate height position h, or which tapers from the top surface to the maximum diameter size of the upper part 70 of the crystal 10 at an intermediate height position h, and from the intermediate height position h toward the back surface, has a size (second diameter size) of the maximum diameter size of the lower part 80 of the crystal 10 + α, which is larger than the maximum diameter size of the upper part 70 of the crystal 10. In the example of FIG. 3, the diameter φ 1 +α, and the diameter φ 2 This shows the case where the opening 42 is formed with an opening portion 42-2 of size +α. Here, α is the margin for achieving a predetermined fitting relationship. Therefore, the counterbore surface 43 (bottom) is formed at height position h.

[0022] The retaining portion 13 is disposed in contact with the back surface side of the lower portion 80 of the crystal 10. The retaining portion 13 holds the crystal 10 so that the crystal 10 does not come off the holding portion 12. The retaining portion 13 is preferably made of the same material as the holding portion 12. The material of the retaining portion 13 can be one of graphite, tantalum, tungsten, and iridium.

[0023] FIG. 4 is a cross-sectional view for explaining an example of a manufacturing method of the cathode mechanism of the electron gun in the first embodiment. As shown in FIG. 4, first, the crystal 10 is inserted into the opening 42 from the back side of the holding part 12. At this time, the crystal 10 is inserted in a direction in which the upper part 70 enters the opening 42 first. Then, the crystal 10 is inserted to a position where the seating surface 81 abuts against the counterbore surface 43 in the opening 42. This allows the electron emission surface 11 to protrude by a predetermined protrusion amount d from the insertion end of the opening 42. If the seating surface 81 and the counterbore surface 43 do not abut, it is difficult to adjust the protrusion amount d. In the first embodiment, the seating surface 81 and the counterbore surface 43 are abutted against each other, so that the crystal 10 can be arranged according to the design dimensions.

[0024] In this way, with the electron emission surface 11 protruding from the end of the opening 42 and the seat surface 81 of the crystal 10 abutting the countersink surface 43 which changes from the maximum diameter size (second diameter size) of the lower part 80 of the crystal 10 within the opening 42 to the maximum diameter size (first diameter size) of the upper part 70 of the crystal 10, the retaining portion 13 holds the crystal 10 on the back side of the lower part 80 of the crystal 10 so that it does not come off the holding portion 12.

[0025] Fig. 5 is a diagram showing an example of a method for fixing the suppressing portion in embodiment 1. In the example of Fig. 5, an adhesive 90 such as a carbon paste material is applied to the side surface of the suppressing portion 13, and the suppressing portion 13 is then inserted into the opening 42 of the holding portion 12. This allows the suppressing portion 13 to be bonded to the holding portion 12. Alternatively, the adhesive 90 can be replaced by a screw, and in this case, for example, the crystallization can be suppressed using the above-mentioned structure and method.

[0026] FIG. 6 is a diagram showing another example of a method for fixing the pressing portion in the first embodiment. In the example of FIG. 6, at least one hole 93 is formed penetrating from the outer periphery side of the holding portion 12 into the opening 42. Each hole 93 is formed at a height position where the pressing portion 13 is disposed. For example, the hole 93 is formed in the horizontal direction. Also, for example, it is preferable to form two holes 93 with a phase shift of 180 degrees. Or, it is even better to form three holes 93 with a phase shift of 120 degrees each. With the pressing portion 13 inserted into the opening 42 of the holding portion 12, a wedge 92 is driven into the pressing portion 13 through the hole 93. This causes the pressing portion 13 to deform and be fixed in the holding portion 12.

[0027] Alternatively, at the height position where the holding portion 13 is disposed, a female screw is formed on the side surface of the holding portion 13 at a position corresponding to the hole 93 in the direction in which the hole 93 extends. Then, with the holding portion 13 inserted into the opening 42 of the holding portion 12, a male screw 94 may be inserted through the hole 93, and further, the male screw 94 may be screwed into the female screw formed on the side surface of the holding portion 13, thereby fixing the holding portion 13 within the holding portion 12. In the example of Fig. 6, the male screw 94 does not have a head, but this is not limited to this. A general bolt with a head may also be used.

[0028] Alternatively, a female screw is formed in a hole 93 formed in the holding portion 12. Then, with the pressing portion 13 inserted into the opening 42 of the holding portion 12, a male screw 94 is screwed into the hole 93 until the tip of the male screw 94 abuts against the pressing portion 13 and further presses it. As a result, the pressing portion 13 is fixed inside the holding portion 12 by friction between the tip of the male screw 94 and the side surface of the pressing portion 13.

[0029] As described above, by configuring the seat surface 81 to abut against the countersunk surface 43, the protrusion amount d of the electron emission surface 11 can be controlled with high precision.

[0030] A pair of supports 14 (first supports) and 16 (second supports) support the holder 12. The pair of supports 14, 16 extend while maintaining the same cross-sectional size. The pair of supports 14, 16 are arranged with a gap width W between them. The pair of supports 14, 16 function as a heater for heating the crystal 10 via the holder 12.

[0031] The pair of base portions 18, 19 fix the pair of pillars 14, 16. Specifically, the base portion 18 fixes the lower end of the pillar 14. The base portion 19 fixes the lower end of the pillar 16. The base portion 18 is connected to a metal wiring 50 supported by an insulator 54, and is supported by the wiring 50. The base portion 19 is connected to a metal wiring 52 supported by the insulator 54, and is supported by the wiring 52.

[0032] The holding portion 12, the pair of support columns 14, 16, and the pair of base portions 18, 19 are formed as an integral structure using the same material. One of graphite, tantalum, tungsten, and iridium can be used as the material for the integral structure. When forming the holding portion 12, the pair of support columns 14, 16, and the pair of base portions 18, 19 as an integral structure, first, a base material is formed in the shape of an upright cylinder in the center of a plate-like base portion. The width L of the base portion is determined by multiplying the diameter φ of the cylinder by the diameter of the cylinder. 4It is preferable to make the size sufficiently larger than the base 18. For example, it is formed to be twice or more the size. In the example of FIG. 2, for example, it is formed to be about three times the size. Then, a cut of width W is made at the center of the longitudinal direction of the base 18, leaving a portion corresponding to the holding part 12 at a position passing through the center of the cylinder, to separate the base 18 from the base 19, and also to separate the support 14 from the support 16. This makes it possible to form a serial flow path through which current flows in the order of the base 18, the support 14, the holding part 12, the support 16, and the base 19. In addition, the above-mentioned opening 42 is formed in the center of the upper surface of the cylindrical holding part 12. This makes it possible to form the holding part 12, the pair of support 14, 16, and the pair of base parts 18, 19, which are integral in structure.

[0033] The current flowing through the electric wire 50 to the base portion 18 of width L can be suppressed in resistance because of the large cross-sectional area, and the amount of heat generated can be suppressed. The resistance is large in the support 14, whose cross-sectional area decreases rapidly from the base portion 18, and the amount of heat generated can be increased. Here, for example, in a shape in which the cross-sectional area gradually decreases, there are few areas with low resistance, and a large amount of power is required to obtain the required amount of heat generated. In contrast, in the first embodiment, the support 14 extends toward the holding portion 12 while maintaining a small cross-sectional area, and therefore a state of high resistance can be maintained. Therefore, when obtaining the required amount of heat, heat can be generated efficiently with a small amount of power. The same is true for the support 16.

[0034] The pair of supports 14, 16 are cut out from a cylindrical portion having a diameter of φ4 as described above. The cylindrical portion having a diameter of φ4 is cut out into two halved portions by forming a notch of width W in the center, leaving the region of the holding portion 12. Furthermore, as shown in the top view of the pair of supports in the upper right of FIG. 1, the portions 2, 3, 4, and 5 on both sides of the halved portion are cut out, respectively, to form the pair of supports 14, 16 having a width D and an arc-shaped outer side of the cross section. As a result, the supports 14, 16 have a cross-sectional structure with three straight sides and one curved side. The cross-sectional area of ​​the supports 14, 16 can be further reduced by further cutting the portions 2, 3, 4, and 5 on both sides of the halved portion. Reducing the cross-sectional area increases the resistance, and the temperature can be efficiently increased when current is passed through the supports.

[0035] FIG. 7 is a diagram for explaining the life of a cathode in a comparative example to the first embodiment. FIG. 8 is a diagram for explaining the life of the cathode in the first embodiment. FIG. 7(a) shows a case where a crystal 60 having a truncated cone-shaped upper part arranged on a cylindrical lower part is used. In the comparative example, the upper surface of the holding part 62 and the upper surface (electron emission surface) of the crystal 60 are arranged so as to be at the same height. Also, the holding part 62 shows a case where a filler material 61 is arranged along the inclined surface of the truncated cone of the crystal 60 with a gap therebetween. In the comparative example, the electron emission surface recedes as shown in FIG. 7(b) due to wear of the crystal 60 during use. When the receding amount Δ reaches a predetermined value, the desired luminance distribution cannot be obtained, and the cathode reaches the end of its life. When the cathode reaches the end of its life, the device must be stopped each time. If the period from the start of use until the receding amount Δ from the upper surface of the holding part 62 reaches a predetermined value is short, the frequency of cathode replacement increases, and the downtime of the device increases. In contrast, in the first embodiment, the electron emission surface 11 is arranged so as to protrude from the upper surface of the holding part 12 by a predetermined protrusion amount d, as shown in FIG. 8. Therefore, the period from the start of use until the recession amount Δ from the top surface of the holding part 62 reaches a predetermined value can be made longer than in the comparative example. This makes it possible to extend the life of the cathode. However, in order to obtain stable beam brightness or uniform brightness distribution, it is not enough to simply make the electron emission surface 11 protrude from the top surface of the holding part 12. It is important to control the protrusion amount d.

[0036] FIG. 9 is a diagram for explaining the relationship between the height position of the electron emission surface of the crystal in the first embodiment and the electric field distribution. In FIG. 9, the height position of the electron emission surface 11 is shown at a height position A that is the same as the upper surface of the holding part 12, at a height position B that protrudes from the upper surface of the holding part 12, at a height position C that protrudes further, and at a height position D that is recessed from the upper surface of the holding part 12. The graph in FIG. 9 shows the electric field distribution near the electron emission surface 11 in each of the states A to D. If the height position of the electron emission surface 11 deviates from the upper surface of the holding part 12, the electric field distribution near the electron emission surface 11 also becomes non-uniform. If the deviation of the height position of the electron emission surface 11 from the upper surface of the holding part 12 becomes large, the deviation of the electric field distribution becomes large accordingly. If the deviation of the electric field distribution becomes large, the lens effect by the electric field becomes large, the beam becomes divergent, and it becomes difficult to control the brightness (or current density) or brightness distribution (or current density distribution) on the sample surface within an allowable range. Therefore, the height position of the electron emission surface 11 needs to be adjusted within an allowable range.

[0037] Fig. 10A is a diagram showing the relationship between the luminance, the cathode temperature, and the emission current, and the protrusion amount of the electron emission surface in embodiment 1. In Fig. 10A, the protrusion amount of the electron emission surface is shown as the ratio of the protrusion amount to the diameter of the electron emission surface 11. Under conditions where the cathode temperature and the emission current are constant, the luminance decreases as the protrusion amount increases. The brightness is higher when more electrons are emitted from the limited electron emission surface 11. And with a protruding structure, electrons are emitted not only from the electron emission surface 11 but also from the outer periphery of the cylinder. With a protruding structure, it becomes necessary to consider the area of ​​the outer periphery in addition to the electron emission surface 11. When comparing under conditions of a constant emission current and the same cathode temperature, the protruding structure crystal 10 has a larger surface area than a non-protruding structure crystal, so the electron density calculated by dividing the emission current by the surface area is lower. As a result, the brightness is lower. In order to maintain a constant brightness, it is necessary to increase the cathode temperature and emission current. However, there is a limit to how much the cathode temperature and emission current can be increased. Therefore, in order to maintain the desired brightness range (tolerance range) for the entire beam, there is a limit to the protrusion amount d of the electron emission surface.

[0038] FIG. 10B is a diagram showing the relationship between the emission current and the protrusion amount of the electron emission surface in the first embodiment. In FIG. 10B, the vertical axis shows the emission current E. The horizontal axis shows the protrusion amount (%) of the electron emission surface. The scales of FIG. 10A and FIG. 10B are not the same. FIG. 10B shows the change in the emission current when the luminance, here the current density J instead of the luminance, is kept constant. When the protrusion amount of the electron emission surface is increased, the luminance (current density) decreases as shown in FIG. 10A, so in order to maintain a constant luminance (current density), the emission current E is increased as shown in FIG. 10B. In addition, the cathode temperature also increases. Increasing the emission current is not preferable because it leads to an increase in the capacity of the power supply that controls the emission current. In addition, the temperature rise of the cathode accelerates the evaporation and sublimation of the crystals, shortening the life. Even if the temperature rise of the cathode is allowed, the maximum value Emax of the emission current E is determined from the guaranteed range of the high-voltage power supply. 10B, the protrusion amount of the electron emission surface at which the emission current E reaches the maximum value Emax is uniquely determined, and the protrusion amount is 10% of the diameter of the electron emission surface. Therefore, it is preferable that the protrusion amount d of the electron emission surface 11 from the upper surface of the holding part 12 be 10% or less of the diameter of the electron emission surface 11.

[0039] In the first embodiment, further protrusion of electron emission surface 11 can be prevented by abutting seat 81 of crystal 10 with countersunk surface 43 of holder 12. Therefore, if the distance between electron emission surface 11 and seat 81 and the distance between the upper surface of holder 12 and countersunk surface 43 are manufactured with high precision, then by abutting seat 81 with countersunk surface 43, assembly can be performed in which the protrusion amount d of electron emission surface 11 is controlled with high precision when manufacturing cathode mechanism 222.

[0040] In the examples of Figs. 1 and 3, the shape of the upper portion 70 of the crystal 10 is columnar, but the shape is not limited to this.

[0041] Fig. 11 is an enlarged cross-sectional view of another example of the crystal, another example of the holding part, and an example of the pressing part in the first embodiment. In the example of Fig. 11, the shape of the upper part 70 of the crystal 10 is a truncated cone. In the example of Fig. 11, the electron emission surface 11 has a diameter φ 1 The lower end of the upper part 70 has a diameter of φ 5 In this case, the maximum diameter size of the upper portion 70 is the diameter φ of the lower end of the upper portion 70. 5 The lower part 80 has a diameter φ 5 Diameter φ is larger than 2 Therefore, the bearing surface 81 is formed in a cylindrical shape with a diameter φ 5 and diameter φ 2 The plane between these two points is called the plane.

[0042] In the holding part 12, an opening 42 is formed which tapers from the top surface to an intermediate height position h, becomes the maximum diameter size of the upper part 70 of the crystal 10 at the intermediate height position h, and becomes the maximum diameter size (second diameter size) of the lower part 80 of the crystal 10 which is larger than the maximum diameter size of the upper part 70 of the crystal 10 from the intermediate height position h toward the back surface side. In the example of Fig. 11, the opening 42 tapers from the top surface to the intermediate height position h along the slope of the upper part 70, and becomes the maximum diameter size of the lower part 80 of the crystal 10 at the intermediate height position h, becoming the maximum diameter size of the lower part 80 of the crystal 10 (second diameter size). 5 +α, and the diameter φ 2 This shows a case where an opening 42 is formed with a size of +α, where α is the margin for achieving a predetermined fit. Therefore, a counterbore surface 43 is formed at height position h.

[0043] Fig. 12 is an enlarged cross-sectional view of another example of the crystal, another example of the holding part, and an example of the pressing part in embodiment 1. The example in Fig. 12 shows a case where the shape of the upper part 70 of crystal 10 is a combination of a columnar shape and a truncated cone shape. The example in Fig. 12 shows a shape in which a cylinder is placed on a truncated cone. In the example in Fig. 12, the part of the upper part 70 of crystal 10 from near the top surface of holding part 12 to electron emission surface 11 is made up of a cylinder, and the part from near the top surface of holding part 12 to lower part 80 of crystal 10 is made up of a truncated cone. In the example in Fig. 12, electron emission surface 11 is a shape with a diameter φ 1 The diameter φ 1 The diameter remains the same, and the diameter φ 1 The diameter φ from the top surface height position of the holding portion 12 5 In this case, the maximum diameter size of the upper portion 70 is the diameter φ 5 The lower part 80 has a diameter φ 5 Diameter φ is larger than 2 Therefore, the bearing surface 81 is formed in a cylindrical shape with a diameter φ 5 and diameter φ 2 The plane between these two points is called the plane.

[0044] In the holding part 12, an opening 42 is formed which tapers from the top surface to an intermediate height position h, where it reaches the maximum diameter size of the upper part 70 of the crystal 10, and from the intermediate height position h toward the back surface, reaches the maximum diameter size (second diameter size) of the lower part 80 of the crystal 10 which is larger than the maximum diameter size of the upper part 70 of the crystal 10. In the example of FIG. 12, the opening 42 has a diameter φ 1 +α, and spreads in a tapered shape along the slope of the upper portion 70 from the upper surface to the intermediate height position h, and at the intermediate height position h, the diameter φ 5 +α, and the diameter φ 2 This shows a case where an opening 42 is formed with a size of +α, where α is the margin for achieving a predetermined fit. Therefore, a counterbore surface 43 is formed at height position h.

[0045] In the above example, a case where there is substantially no gap between the side surface of opening 42 of holder 12 and the side surface of upper portion 70 of crystal 10 has been described, but the present invention is not limited to this.

[0046] Fig. 13 is an enlarged cross-sectional view of an example of a crystal, another example of a holding part, and an example of a pressing part in embodiment 1. The example in Fig. 13 shows a configuration in which a gap G is provided between the side surface of upper part 70 of crystal 10 and holding part 12. The other configurations are the same as those in Fig. 3.

[0047] Fig. 14 is an enlarged cross-sectional view of another example of the crystal, another example of the holding part, and an example of the pressing part in embodiment 1. The example in Fig. 14 shows a configuration in which a gap G is provided between the truncated cone slope of the upper part 70 of crystal 10 and holding part 12. The other configurations are the same as those in Fig. 11.

[0048] Fig. 15 is an enlarged cross-sectional view of another example of the crystal, another example of the holding part, and an example of the pressing part in embodiment 1. The example in Fig. 15 shows a configuration in which a gap G is provided between the truncated cone slope of the upper part 70 of crystal 10 and holding part 12. The other configurations are the same as those in Fig. 12.

[0049] It does not matter which of the configurations shown in Fig. 3 and Fig. 11 to Fig. 15 is used. In any case, it is possible to extend the life of the cathode while controlling the amount of protrusion of the electron emission surface 11 with high precision.

[0050] FIG. 16 is a diagram showing an example of the configuration of the drawing apparatus in the first embodiment. In FIG. 16, the drawing apparatus 100 includes a drawing mechanism 150 and a control circuit 160. The drawing apparatus 100 is an example of a multi-electron beam drawing apparatus. The drawing mechanism 150 includes an electron lens barrel 102 (multi-electron beam column) and a drawing chamber 103. In the electron lens barrel 102, an electron gun 201, an illumination lens 202, a shaping aperture array substrate 203, a blanking aperture array mechanism 204, a reduction lens 205, a limiting aperture substrate 206, an objective lens 207, a deflector 208, and a deflector 209 are arranged. In the drawing chamber 103, an XY stage 105 is arranged. On the XY stage 105, a sample 101 such as a mask blank coated with a resist, which is a substrate to be drawn during drawing, is arranged. The sample 101 includes an exposure mask for manufacturing a semiconductor device, a semiconductor substrate (silicon wafer) on which the semiconductor device is manufactured, and the like. Further, a mirror 210 for measuring the position of the XY stage 105 is disposed on the XY stage 105 .

[0051] The electron gun 201 (electron beam emission source) has the above-mentioned cathode mechanism 222. In addition to the cathode mechanism 222, the electron gun 201 has a Wehnelt 224 (Wehnelt electrode) and an anode 226 (anode electrode). The anode 226 is controlled to a state of a more positive potential than the crystal 10 of the cathode mechanism 222, and draws out thermoelectrons emitted from the crystal 10. For example, the anode 226 is grounded (earthed).

[0052] The control circuit 160 includes a control computer 110, a memory 112, an electron gun power supply device 120, a deflection control circuit 130, digital-to-analog conversion (DAC) amplifier units 132 and 134, a stage position detector 139, and a storage device 140 such as a magnetic disk device. The control computer 110, the memory 112, the electron gun power supply device 120, the deflection control circuit 130, the DAC amplifier units 132 and 134, the stage position detector 139, and the storage device 140 are connected to each other via a bus (not shown). The DAC amplifier units 132 and 134 and a blanking aperture array mechanism 204 are connected to the deflection control circuit 130. The output of the DAC amplifier unit 132 is connected to a deflector 209. The output of the DAC amplifier unit 134 is connected to a deflector 208. The deflector 208 is composed of four or more electrodes, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 134. The deflector 209 is composed of four or more electrodes, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 132. The stage position detector 139 irradiates a mirror 210 on the XY stage 105 with laser light, and receives the reflected light from the mirror 210. Then, the position of the XY stage 105 is measured by utilizing the principle of laser interference using information on the reflected light.

[0053] Information input to and output from the control computer 110 and information being calculated are stored in the memory 112 each time.

[0054] In the electron gun power supply device 120, an acceleration voltage power supply circuit 236, a bias voltage power supply circuit 234, a filament power supply circuit 231 (filament power supply unit), and an ammeter 238 are arranged.

[0055] The cathode (-) side of the acceleration voltage power supply circuit 236 is connected to the wirings 50, 52 of both poles of the cathode mechanism 222 in the electron microscope column 102. The anode (+) side of the acceleration voltage power supply circuit 236 is grounded (grounded) via an ammeter 238 connected in series. The cathode (-) of the acceleration voltage power supply circuit 236 is also branched and connected to the anode (+) of the bias voltage power supply circuit 234, and the cathode (-) of the bias voltage power supply circuit 234 is electrically connected to the Wehnelt 224 arranged between the cathode mechanism 222 and the anode 226. In other words, the bias voltage power supply circuit 234 is arranged so as to be electrically connected between the cathode (-) of the acceleration voltage power supply circuit 236 and the Wehnelt 224. The filament power supply circuit 231 passes a current between the wirings 50, 52 of both poles of the cathode mechanism 222 to heat the crystal 10 in the cathode mechanism 222 to a predetermined temperature. In other words, the filament power supply circuit 231 supplies filament power to the cathode mechanism 222. A certain relationship can be defined between the filament power and the cathode temperature T (heating temperature of the crystal 10), and the cathode can be heated to a desired temperature by the filament power. Thus, the cathode temperature T is controlled by the filament power. The filament power is defined as the product of the current flowing between the two poles of the cathode mechanism 222 and the voltage applied between the two poles of the cathode mechanism 222 by the filament power supply circuit 231. The acceleration voltage power supply circuit 236 applies an acceleration voltage between the cathode mechanism 222 and the anode 226. The bias voltage power supply circuit 234 applies a negative bias voltage to the Wehnelt 224.

[0056] Moreover, drawing data is input from outside the drawing device 100 and stored in the storage device 140. The drawing data usually defines information on a plurality of graphic patterns to be drawn. Specifically, a graphic code, coordinates, size, etc. are defined for each graphic pattern.

[0057] 16 shows the configuration necessary for explaining the embodiment 1. The drawing device 100 may also include other configurations that are normally required.

[0058] FIG. 17 is a conceptual diagram showing the configuration of the shaping aperture array substrate in the first embodiment. In FIG. 17, holes (openings) 22 are formed in a matrix of p columns (y direction)×q columns (x direction) (p, q≧2) at a predetermined arrangement pitch in the shaping aperture array substrate 203. In FIG. 17, for example, 512×512 columns of holes 22 are formed in the vertical and horizontal directions (x and y directions). Each hole 22 is formed in a rectangular shape with the same dimensions. Alternatively, they may be circular shapes with the same diameter. The shaping aperture array substrate 203 (beam forming mechanism) forms a multi-beam 20. Specifically, a part of the electron beam 200 passes through each of the multiple holes 22, thereby forming the multi-beam 20. In addition, the arrangement of the holes 22 is not limited to the case where the holes 22 are arranged in a lattice shape vertically and horizontally as shown in FIG. 17. For example, the holes in the kth column and the k+1th column in the vertical direction (y direction) may be shifted by a dimension a in the horizontal direction (x direction). Similarly, the holes in the k+1th column and the k+2th column in the vertical direction (y direction) may be shifted by a dimension b in the horizontal direction (x direction).

[0059] FIG. 18 is a cross-sectional view showing the configuration of the blanking aperture array mechanism in the first embodiment. In the blanking aperture array mechanism 204, as shown in FIG. 18, a semiconductor substrate 31 made of silicon or the like is placed on a support base 33. The central part of the substrate 31 is cut from, for example, the back side and processed into a membrane region 330 (first region) with a thin film thickness h. The periphery surrounding the membrane region 330 becomes an outer peripheral region 332 (second region) with a thick film thickness H. The upper surface of the membrane region 330 and the upper surface of the outer peripheral region 332 are formed to be at the same height position or to be substantially at the same height position. The substrate 31 is held on the support base 33 at the back side of the outer peripheral region 332. The central part of the support base 33 is open, and the position of the membrane region 330 is located in the open region of the support base 33.

[0060] In the membrane region 330, a passage hole 25 (opening) for passing each beam of the multibeam 20 is opened at a position corresponding to each hole 22 of the shaping aperture array substrate 203 shown in FIG. 17. In other words, a plurality of passage holes 25 through which the corresponding beams of the multibeam 20 using electron beams pass is formed in an array in the membrane region 330 of the substrate 31. Then, on the membrane region 330 of the substrate 31, a plurality of electrode pairs having two electrodes are arranged at positions facing each other across the corresponding passage hole 25 among the plurality of passage holes 25. Specifically, on the membrane region 330, as shown in FIG. 8, a pair of a control electrode 24 for blanking deflection and a counter electrode 26 (blanker: blanking deflector) is arranged on each of the membrane regions 330, with the passage hole 25 corresponding to the position adjacent to each passage hole 25 being interposed therebetween. Also, inside the substrate 31, and in the vicinity of each passage hole 25 on the membrane region 330, a control circuit 41 (logic circuit) for applying a deflection voltage to the control electrode 24 for each passage hole 25 is arranged. The counter electrode 26 for each beam is connected to ground.

[0061] In the control circuit 41, an amplifier (not shown) such as a CMOS inverter circuit (one example of a switching circuit) is disposed. The output line (OUT) of the amplifier is connected to the control electrode 24. On the other hand, the counter electrode 26 is applied with a ground potential. Either an L (low) potential (for example, ground potential) lower than the threshold voltage or an H (high) potential (for example, 1.5 V) equal to or higher than the threshold voltage is applied as a control signal to the input (IN) of the amplifier. In the first embodiment, when an L potential is applied to the input (IN) of the amplifier, the output (OUT) of the amplifier becomes a positive potential (Vdd), and the corresponding beam is deflected by an electric field due to a potential difference with the ground potential of the counter electrode 26, and the beam is controlled to be turned OFF by blocking with the limiting aperture substrate 206. On the other hand, when an H potential is applied to the input (IN) of the amplifier (active state), the output (OUT) of the amplifier becomes a ground potential, and the potential difference with the ground potential of the counter electrode 26 disappears and the corresponding beam is not deflected, so that the beam is controlled to be turned ON by passing through the limiting aperture substrate 206.

[0062] The pairs of control electrodes 24 and counter electrodes 26 individually blank and deflect the corresponding beams of the multi-beams 20 by the potentials switched by the amplifiers serving as the corresponding switching circuits. In this manner, the multiple blankers perform blanking deflection of the corresponding beams of the multi-beams 20 that have passed through the multiple holes 22 (openings) of the shaping aperture array substrate 203.

[0063] Next, the operation of the drawing mechanism 150 in the drawing apparatus 100 will be described. The drawing mechanism 150 draws a pattern on the sample 101 using thermal electrons emitted from the electron gun 201. Specifically, the drawing mechanism 150 operates as follows. An electron beam 200 emitted from the electron gun 201 (electron emission source) illuminates the entire shaping aperture array substrate 203 by an illumination lens 202. A plurality of rectangular holes 22 (openings) are formed in the shaping aperture array substrate 203, and the electron beam 200 illuminates an area including all of the plurality of holes 22. Each part of the electron beam 200 irradiated to the position of the plurality of holes 22 passes through each of the plurality of holes 22 of the shaping aperture array substrate 203, thereby forming a plurality of electron beams (multi-beams 20) having, for example, a rectangular shape. The multi-beams 20 pass through the corresponding blankers (first deflectors: individual blanking mechanisms) of the blanking aperture array mechanism 204. Each such blanker individually deflects the electron beam passing through it (performs blanking deflection).

[0064] The multi-beams 20 that have passed through the blanking aperture array mechanism 204 are reduced by the reduction lens 205 and proceed toward the central hole formed in the limiting aperture substrate 206. Here, among the multi-beams 20, the electron beams deflected by the blanker of the blanking aperture array mechanism 204 are displaced from the central hole of the limiting aperture substrate 206 and are blocked by the limiting aperture substrate 206. On the other hand, the electron beams that have not been deflected by the blanker of the blanking aperture array mechanism 204 pass through the central hole of the limiting aperture substrate 206 as shown in FIG. 1. Blanking control is performed by turning on / off the individual blanking mechanisms, and the beams are turned on / off. Then, the beams that have passed through the limiting aperture substrate 206 and that have been formed for each beam from when the beam is turned on until when the beam is turned off form a beam for one shot. The multi-beams 20 that have passed through the limiting aperture substrate 206 are focused by the objective lens 207 to become a pattern image with a desired reduction ratio, and each beam that has passed through the limiting aperture substrate 206 (the entire multi-beams 20 that have passed through) is deflected collectively in the same direction by the deflectors 208 and 209, and each beam is irradiated onto its respective irradiation position on the sample 101. The multi-beams 20 that are irradiated at one time are ideally arranged at a pitch obtained by multiplying the arrangement pitch of the multiple holes 22 in the shaping aperture array substrate 203 by the desired reduction ratio described above.

[0065] FIG. 19 is a conceptual diagram for explaining an example of the writing operation in the first embodiment. As shown in FIG. 19, the writing region 30 of the sample 101 is virtually divided into a plurality of stripe regions 32 each having a predetermined width in the y direction. First, the XY stage 105 is moved to adjust the irradiation region 34 that can be irradiated with one shot of the multi-beam 20 to be located at the left end of the first stripe region 32 or at a position further to the left, and writing is started. When writing the first stripe region 32, the XY stage 105 is moved, for example, in the -x direction to relatively advance writing in the x direction. The XY stage 105 is moved continuously at a constant speed, for example. After writing the first stripe region 32 is completed, the stage position is moved in the -y direction to adjust the irradiation region 34 to be located at the right end of the second stripe region 32 or at a position further to the right in the y direction, and then the XY stage 105 is moved, for example, in the x direction to similarly perform writing in the -x direction. The writing time can be reduced by alternately changing the direction of writing, such as writing in the x direction in the third stripe region 32 and writing in the -x direction in the fourth stripe region 32. However, writing may be performed in the same direction when writing each stripe region 32, not limited to the alternately changing direction of writing. In one shot, a plurality of shot patterns, the same number as the number of holes 22 formed in the shaping aperture array substrate 203, is formed at once by the multi-beam formed by passing through each hole 22 in the shaping aperture array substrate 203. In addition, the example of FIG. 19 shows a case where each stripe region 32 is written once, but this is not limited to this. Multiple writing, in which the same region is written multiple times, may also be performed. When performing multiple writing, it is preferable to set the stripe regions 32 of each pass while shifting the positions.

[0066] FIG. 20 is a diagram showing an example of the irradiation area of ​​the multi-beam and the pixel to be written in the first embodiment. In FIG. 20, a plurality of control grids 27 (design grids) are set in the stripe area 32, which are arranged in a lattice shape with a beam size pitch of the multi-beam 20 on the surface of the sample 101. For example, an arrangement pitch of about 10 nm is preferable. Such a plurality of control grids 27 are the designed irradiation positions of the multi-beam 20. The arrangement pitch of the control grid 27 is not limited to the beam size, and may be configured with an arbitrary size that can be controlled as the deflection position of the deflector 209 regardless of the beam size. Then, a plurality of pixels 36 are set that are virtually divided into a mesh shape with the same size as the arrangement pitch of the control grid 27, with each control grid 27 at the center. Each pixel 36 is an irradiation unit area for one beam of the multi-beam. The example of FIG. 20 shows a case where the writing area of ​​the sample 101 is divided into a plurality of stripe areas 32 with a width size substantially the same as the size of the irradiation area 34 (writing field) that can be irradiated by one irradiation of the multi-beam 20, for example, in the y direction. The x-direction size of the irradiation area 34 can be defined as a value obtained by multiplying the inter-beam pitch of the multibeam 20 in the x direction by the number of beams in the x direction. The y-direction size of the irradiation area 34 can be defined as a value obtained by multiplying the inter-beam pitch of the multibeam 20 in the y direction by the number of beams in the y direction. The width of the stripe area 32 is not limited to this. It is preferable that the size is n times (n is an integer of 1 or more) the size of the irradiation area 34. In the example of FIG. 20, for example, the illustration of 512×512 rows of multibeams is abbreviated to 8×8 rows of multibeams. Then, a plurality of pixels 28 (beam drawing positions) that can be irradiated by one shot of the multibeam 20 are shown in the irradiation area 34. In other words, the pitch between adjacent pixels 28 is the pitch between each beam of the multibeam in the design. In the example of FIG. 20, one sub-irradiation area 29 is formed by an area surrounded by the inter-beam pitch. In the example of FIG. 20, a case where each sub-irradiation area 29 is formed by 4×4 pixels is shown.

[0067] FIG. 21 is a diagram for explaining an example of a multi-beam writing method in the first embodiment. FIG. 21 shows a part of the sub-irradiation area 29 written by each beam of coordinates (1,3), (2,3), (3,3), . . . , (512,3) in the third row in the y direction among the multi-beams that write the stripe area 32 shown in FIG. 20. The example of FIG. 6 shows, for example, a case where four pixels are written (exposed) while the XY stage 105 moves a distance of eight beam pitches. While writing (exposing) these four pixels, the deflector 208 deflects the entire multi-beam 20 collectively so that the relative position of the irradiation area 34 with respect to the sample 101 does not shift due to the movement of the XY stage 105, thereby making the irradiation area 34 follow the movement of the XY stage 105. In other words, tracking control is performed. The example of FIG. 21 shows a case where one tracking cycle is performed by writing (exposing) four pixels while shifting the pixel 36 to be irradiated with the beam in the y direction for each shot while moving a distance of eight beam pitches.

[0068] Specifically, the drawing mechanism 150 irradiates each control grid 27 with the corresponding ON beam of the multi-beam 20 for a drawing time (irradiation time or exposure time) corresponding to each control grid 27 within the maximum irradiation time Ttr among the irradiation times of each beam of the multi-beam in the shot. The maximum irradiation time Ttr is set in advance. In reality, the shot cycle is the maximum irradiation time Ttr plus the settling time of the beam deflection, but here, the settling time of the beam deflection is omitted and the maximum irradiation time Ttr is shown as the shot cycle. Then, when one tracking cycle is completed, the tracking control is reset and the tracking position is swung back to the start position of the next tracking cycle.

[0069] Since drawing of the first pixel row from the right in each sub-irradiation area 29 has been completed, after tracking reset, in the next tracking cycle, the deflector 209 first deflects the beam so as to align (shift) the drawing position of the beam corresponding to the control grid 27 of the first row from the bottom and the second pixel from the right in each sub-irradiation area 29.

[0070] As described above, during the same tracking cycle, the deflector 208 controls the irradiation region 34 so that the relative position with respect to the sample 101 is the same, and the deflector 209 shifts the irradiation region 34 by one control grid 27 (pixel 36) to perform each shot. After one tracking cycle is completed, the tracking position of the irradiation region 34 is returned, and then, as shown in the lower part of FIG. 10, the first shot position is aligned to a position shifted by one control grid (one pixel), for example, and each shot is performed while shifting the irradiation region 34 by one control grid (one pixel) while performing the next tracking control. By repeating such an operation during drawing of the stripe region 32, the position of the irradiation region 34 moves sequentially from the irradiation regions 34a to 34o, and drawing of the stripe region is performed.

[0071] Which of the multi-beams irradiates which control grid 27 (pixel 36) on the sample 101 is determined by the drawing sequence. If the sub-irradiation area 29 is an area of ​​n×n pixels, n control grids (n pixels) are drawn in one tracking operation. In the next tracking operation, n pixels are similarly drawn by a beam different from the above-mentioned beam. In this way, n pixels are drawn by different beams in n tracking operations, and all pixels in one n×n pixel area are drawn. Similar operations are performed at the same time for other n×n pixel sub-irradiation areas 29 in the multi-beam irradiation area, and drawing is performed in the same manner.

[0072] As described above, according to the first embodiment, the amount of crystal 10 protruding from the upper surface of holder 12 can be controlled with high precision. As a result, the life of cathode mechanism 222 that can obtain a desired luminance distribution can be extended. Thus, the downtime of imaging apparatus 100 can be reduced.

[0073] Although the embodiments have been described above with reference to specific examples, the present invention is not limited to these specific examples.

[0074] Although the description of the device configuration, control method, and other parts not directly necessary for the explanation of the present invention have been omitted, the required device configuration and control method can be appropriately selected and used. For example, the description of the control unit configuration that controls the drawing device 100 has been omitted, but it goes without saying that the required control unit configuration can be appropriately selected and used.

[0075] In addition, all cathode mechanisms of electron guns, electron guns, and electron beam writing apparatuses that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included within the scope of the present invention. [Explanation of symbols]

[0076] 2,3,4,5 parts 10 crystals 11 Electron emitting surface 12 Holding part 13 Retaining part 14,16 pillars 18,19 Base 20 Multibeam 22 holes 24 Control electrode 25 Passing hole 26 Counter electrode 27 Control Grid 28 pixels 29 Sub-irradiation area 30 drawing area 32 Stripe Area 31 Substrate 33 Support stand 34 Irradiation area 35 Unit Area 36 pixels 41 Control circuit 42 Opening 43 Countersunk surface 54 Insulator 50,52 Wiring 60 crystal 61 Filler material 62 Holding part 70 Top 80 Lower 81 Seat 100 drawing device 101 Sample 102 Electron Tube 103 Drawing room 105 XY Stage 110 Control computer 112 Memory 120 Electron gun power supply unit 130 Deflection control circuit 132,134 DAC amplifier unit 139 Stage Position Detector 140 Storage device 150 Drawing mechanism 160 Control Circuits 200 Electron Beam 201 Electron Gun 202 Lighting lens 203 Shaped aperture array substrate 204 Blanking Aperture Array Mechanism 205 Reduction Lens 206 Limiting Aperture Board 207 Objective Lens 208,209 Deflector 210 Mirror 222 Cathode Mechanism 224 Wehnelt 226 Anode 231 Filament power supply circuit 234 Bias voltage power supply circuit 236 Accelerating voltage power supply circuit 238 Ammeter 330 Membrane Region 332 Outer area

Claims

1. A crystal having an upper portion having a columnar shape, a truncated cone shape, or a combination thereof, and having a first surface that emits thermoelectrons when heated, and a lower portion having a second surface that is approximately parallel to the first surface and has a diameter larger than the maximum diameter of the upper portion, and being integral with the upper portion; a holding section formed in a cylindrical shape having a plurality of different inner diameters, a first diameter size and a second diameter size larger than the first diameter size, from the upper surface side, the holding section holding the crystal in a state in which the first surface of the crystal protrudes from the upper surface and abuts against the second surface of the crystal within the cylinder; a holding portion that holds the crystal on a back surface side of the lower portion of the crystal so that the crystal does not come off the holding portion; A cathode mechanism for an electron gun comprising:

2. 2. The cathode mechanism for an electron gun according to claim 1, wherein the amount by which said first surface protrudes from the upper surface of said holder is 10% or less of a diameter of said first surface.

3. 3. The cathode mechanism of an electron gun as claimed in claim 1, wherein an opening is formed in the holding portion, the opening having the first diameter size from the top surface to an intermediate height position, or the opening having the first diameter size at the intermediate height position while expanding from the top surface, and the opening having the second diameter size larger than the first diameter size from the intermediate height position toward the back surface side.

4. 4. The cathode mechanism of an electron gun according to claim 1, further comprising first and second support columns supporting said holding portion, each of said support columns extending while maintaining the same cross-sectional size.

5. 5. The cathode mechanism for an electron gun according to claim 1, wherein said holding portion and said pressing portion are made of the same material.

6. a step of inserting a crystal having a columnar, truncated cone or combination thereof upper part having a first surface that emits thermoelectrons when heated, and a lower part integral with the upper part, the lower part having a second surface that is substantially parallel to the first surface and has a diameter larger than the maximum diameter of the upper part, into the openings from the back side of a cylindrical holder having a plurality of openings with different inner diameters, the openings having a first diameter size and a second diameter size larger than the first diameter size from the top side; a step of holding the crystal on the back side of the lower part of the crystal with a holding part so that the crystal does not come off the holding part while the first surface protrudes from the end of the opening and the second surface of the crystal is abutted against a surface in the opening where the diameter size changes from the second diameter size to the first diameter size; A method for manufacturing a cathode mechanism for an electron gun, comprising:

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