Cathode mechanism of electron gun, electron gun and electron beam drawing device

Abstract

The cathode mechanism of an electron gun according to one embodiment of the present invention is characterized in that it comprises: a crystal that emits thermal electrons from one end face by heating; a holding portion that holds the crystal in a state where the one end face is exposed and covers at least a portion of the other faces of the crystal; a first pillar and a second pillar that support the holding portion and extend while maintaining the same cross-sectional dimensions; a first base that fixes the first pillar; and a second base that fixes the second pillar, wherein the holding portion, the first pillar and the second pillar, and the first base and the second base are formed by an integral structure based on the same material, and the crystal is heated by flowing an electric current in the integral structure.

Description

[0001] Cross-references to related applications

[0002] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2021-029008 filed in Japan on February 25, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One aspect of the present application relates to a cathode mechanism of an electron gun, an electron gun, and an electron beam imaging device. Background Art

[0004] The photolithography technology that is responsible for the progress of miniaturization of semiconductor devices is also an extremely important process for generating unique patterns in the semiconductor manufacturing process. In recent years, with the high integration of LSI, the circuit line width required by semiconductor devices has been miniaturized year by year. Here, the electron beam (electron beam) drawing technology has excellent resolution in nature and uses electron beams to draw mask patterns on mask blanks.

[0005] For example, there is a drawing device using multiple beams. Compared with the case of drawing using a single electron beam, since multiple beams can be irradiated at one time by using multiple beams, productivity can be greatly improved. In this multi-beam drawing device, for example, the electron beam emitted from the electron gun is passed through a mask with multiple holes to form multiple beams, and blanking control is performed on each beam. The unblocked beams are reduced by the optical system, the mask image is reduced, deflected by the deflector, and irradiated to the desired position on the sample.

[0006] In a thermionic gun that emits an electron beam, the operating temperature of the cathode becomes higher as the brightness of the cathode increases. In the past, the cathode mechanically joined and assembled multiple parts through which current flows. Therefore, there are multiple electrical contact positions, so there is a problem that the resistance of the cathode as a whole becomes unstable. In addition, when multiple parts through which current flows are fixed in the ceramic as an insulating part, there is a problem that the ceramic also becomes high temperature when heated and insulation breakdown is likely to occur.

[0007] Here, the following cathode structure is disclosed, in which a pair of terminals for conducting electricity, a pair of legs extending so that the cross-sectional area gradually decreases from each terminal, and a supporting portion connecting the pair of legs at the thinnest part and carrying lanthanum hexaboride (LaB6) powder are integrally formed by glassy carbon (for example, refer to Japanese Patent Gazette No. 2001-084932). Summary of the invention

[0008] A cathode mechanism of an electron gun according to one aspect of the present application is characterized by comprising:

[0009] A crystal, which is heated to emit hot electrons from one end face;

[0010] A holding portion that holds the crystal in a state where one end face is exposed and at least a portion of other faces of the crystal is covered;

[0011] The first support and the second support support the holding portion and extend while maintaining the same cross-sectional dimensions.

[0012] a first base portion to fix the first support column; and

[0013] The second base, fixes the second support,

[0014] The holding portion, the first and second pillars, and the first and second bases are formed by an integral structure based on the same material, and the crystal is heated by flowing an electric current in the integral structure.

[0015] An electron gun according to one aspect of the present invention is characterized by comprising:

[0016] The cathode mechanism of the electron gun mentioned above; and

[0017] The anode electrode is controlled to be in a state of positive potential compared to the crystal, and is used to extract thermal electrons emitted from the crystal.

[0018] An electron beam drawing device according to one aspect of the present invention is characterized by comprising:

[0019] The electron gun as described above; and

[0020] The drawing mechanism draws a pattern on the sample using thermal electrons emitted from an electron gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a cross-sectional view showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment.

[0022] Figure 2 This is a plan view showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment.

[0023] Figure 3 This is a perspective view for reference showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment.

[0024] Figure 4 This is a structural diagram showing an example of a cathode mechanism in Comparative Example 1 of Embodiment 1.

[0025] Figure 5 This is a structural diagram showing an example of a cathode mechanism in Comparative Example 2 of Embodiment 1.

[0026] Figure 6 This is a diagram showing an example of the configuration of the drawing device in the first embodiment.

[0027] Figure 7 This is a conceptual diagram showing the structure of the formed aperture array substrate in the first embodiment.

[0028] Figure 8 This is a cross-sectional view showing the structure of the blanking aperture array mechanism in the first embodiment.

[0029] Fig. 9 This is a conceptual diagram for explaining an example of the drawing operation in the first embodiment.

[0030] Fig.10 This is a diagram showing an example of a multi-beam irradiation area and drawing target pixels in the first embodiment.

[0031] Fig.11 This is a diagram for explaining an example of a multi-beam drawing method in the first embodiment. DETAILED DESCRIPTION

[0032] In the following, in the embodiments, a cathode mechanism that can efficiently heat a crystal while achieving stability of cathode resistance and suppression of dielectric breakdown will be described.

[0033] In the following embodiments, a configuration using multiple electron beams is described. However, the present invention is not limited thereto, and a configuration using a single electron beam may be used. In the following, a drawing device is described, but any device using electron beams emitted from a thermal electron emission source may be used, and a device other than a drawing device may be used. For example, an image acquisition device or an inspection device may be used.

[0034] Implementation method 1.

[0035] Figure 1 This is a cross-sectional view showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment.

[0036] Figure 2 This is a plan view showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment.

[0037] Figure 3 This is a perspective view for reference showing an example of the configuration of a cathode mechanism of the electron gun in the first embodiment. Figure 3 The shape of the cathode structure shown is partly Figure 1 as well as Figure 2 The shapes shown are not consistent. Figure 1 as well as Figure 2 In FIG. 1 , the cathode mechanism 222 (cathode mechanism) of the electron gun includes a crystal 10 , a holding portion 12 , a pair of supporting columns 14 , 16 , and a pair of bases 18 , 19 .

[0038] The crystal 10 emits hot electrons from the electron emission surface 11 as one end surface by heating. As the material of the crystal 10, for example, lanthanum hexaboride (LaB6) is used. The crystal orientation in the electron emission surface 11 of the crystal 10 is the same. For example, it is preferable to have a crystal orientation of (100) or (310). The crystal 10 is formed into at least one of a cylindrical shape and a truncated cone shape. For example, Figure 1 As shown, it is preferably formed into a combination of a cylindrical lower part and a truncated cone upper part. Alternatively, it can be formed into a cylindrical shape from the lower part to the upper part. Alternatively, it can be formed into a truncated cone shape from the lower part to the upper part. Alternatively, it can be a prism.

[0039] The holding portion 12 exposes the electron emission surface 11 of the crystal 10 and holds the crystal 10 while covering at least a portion of the other surfaces of the crystal 10. A hole is formed at a predetermined depth in the center of the upper surface of the cylindrical holding portion 12. The size of the hole matches the size of the crystal 10. The crystal 10 is held by inserting the crystal 10 into the hole from the lower side. Figure 1 In the example of the embodiment, the bottom surface and the side surface of the lower part of the crystal 10 are covered. The holding part 12 contacts the crystal 10 in the covered surface, heats the crystal 10 and applies an accelerating voltage to the crystal 10. For example, when the crystal 10 is a cylinder, a truncated cone, or a combination of the two, the shape of the hole of the holding part 12 can be set to a cylinder. For example, when the crystal 10 is a prism, the shape of the hole of the holding part 12 can be set to a prism.

[0040] A pair of pillars 14 (first pillar) and a pillar 16 (second pillar) support the holding portion 12. The pair of pillars 14 and 16 extend while maintaining the same cross-sectional dimensions. The pair of pillars 14 and 16 are arranged to be separated by a gap width W. The pair of pillars 14 and 16 function as a heater for heating the crystal 10 via the holding portion 12.

[0041] The pair of bases 18 and 19 fix the pair of pillars 14 and 16. Specifically, the base 18 fixes the lower end of the pillar 14. The base 19 fixes the lower end of the pillar 16. The base 18 is connected to the metal wiring 50 supported by the insulating member 54 and supported by the wiring 50. The base 19 is connected to the metal wiring 52 supported by the insulating member 54 and supported by the wiring 52.

[0042] The retaining portion 12, a pair of pillars 14, 16, and a pair of bases 18, 19 are formed by an integral structure based on the same material. As a material for the integral structure, one of graphite, tantalum, tungsten and iridium can be used. When the retaining portion 12, a pair of pillars 14, 16, and a pair of bases 18, 19 are formed as an integral structure, first, the base material is formed into a shape in which a cylinder stands upright in the center of a plate-like base portion. The width L of the base portion is preferably set to a size that is sufficiently larger than the diameter φ of the cylinder. For example, it is formed to a size that is twice or more. Figure 2 as well as Figure 3 In the example of , a case where the size is about 3 times the size is shown. Then, at the central part of the length direction of the base and passing through the central part of the cylinder, a portion corresponding to the holding portion 12 is retained and a cut of width W is performed to separate the base 18 from the base 19 and the pillar 14 from the pillar 16. Thus, a series flow path can be formed in which the current flows in the order of the base 18, the pillar 14, the holding portion 12, the pillar 16 and the base 19. In addition, a space of the same width W is formed continuously between the two pillars 14 and 16 and between the two bases 18 and 19 from the back of the holding portion 12. In addition, a hole is formed at a predetermined depth in the central part of the upper surface of the cylindrical holding portion 12. The diameter of the hole matches the size of the crystal 10. The depth of the hole is preferably set to be less than the length of the crystal 10. Thus, a holding portion 12, a pair of pillars 14 and 16 and a pair of bases 18 and 19 of an integral structure can be formed.

[0043] Regarding the current flowing in the base 18 of width L via the wire 50, the resistance can be suppressed to be small due to the large cross-sectional area, thereby suppressing the heat generation. Moreover, in the pillar 14 whose cross-sectional area decreases sharply from the base 18, the heat generation can be increased due to the large resistance. Here, for example, in a shape with a gradually decreasing cross-sectional area, there are fewer parts with large resistance, and a large amount of electricity is required to obtain the required heat generation. In contrast, in embodiment 1, the pillar 14 can extend toward the retaining portion 12 while maintaining a small cross-sectional area, so that a state with a large resistance can be maintained. As a result, when the required heat generation is obtained, heat can be efficiently generated with a small amount of electricity. The same is true for the pillar 16.

[0044] The pair of pillars 14 and 16 are cut from the cylindrical portion of diameter φ as described above. The cylindrical portion of diameter φ is cut into two halves by leaving the region of the holding portion 12 and forming a cutout of width W in the center. Figure 1As shown in the top view of a pair of pillars on the upper right of the figure, the parts 2, 3, 4, and 5 on both sides of the half-divided part are cut respectively, so as to form a pair of pillars 14 and 16 whose outer sides of the cross section are arc-shaped with a width D. Thus, the pillars 14 and 16 have a cross-sectional structure in which three sides are straight lines and one side is a curve. By further cutting the parts 2, 3, 4, and 5 on both sides of the half-divided part, the cross-sectional area of ​​the pillars 14 and 16 can be further reduced. By reducing the cross-sectional area, the resistance is increased, and the temperature can be efficiently increased when the current is passed.

[0045] Thus, for example, the heater can be easily manufactured by cutting out the slit (W) and the parts 2, 3, 4, and 5 from a cylinder made by lathing a graphite material. In other words, it is a structure that is easy to manufacture. Moreover, since the cylinder is homogeneous by lathing and has less stress under a weak load, it is difficult for the cylinder itself to crack. Moreover, the cross-sectional area is small, which can increase the resistance, and the cross-sectional shape is quadrilateral, which further increases the strength.

[0046] Figure 4 1 is a structural diagram showing an example of a cathode structure in Comparative Example 1 of Implementation Example 1. Figure 4 In Comparative Example 1, for example, two leads 350 that vertically penetrate a disc-shaped ceramic base 354 from the outside and are fixed are bent inward and extended to each other after penetrating the ceramic base 354. Moreover, the crystal 310 is clamped by a plate-like pyrolytic graphite (PG) 312 at the front end portion of the two leads 350. In this structure, there are positions where each lead 350 is mechanically and electrically bonded to each PG 312, and positions where the two PGs 312 are mechanically and electrically bonded to the crystal 310. In particular, the crystal 310 is bonded at the front end portion of each plate-like PG 312. Therefore, there is a problem that the contact resistance at these bonding positions is easily changed.

[0047] Figure 5 1 is a structural diagram showing an example of a cathode structure in Comparative Example 2 of Implementation Example 1. Figure 5In Comparative Example 2, for example, two base pins 450 and 452 extend obliquely inward from the outer peripheral portion of the upper surface of a disc-shaped ceramic base 454, and a leaf spring 418 is connected to the front end portion of the base pin 450. Similarly, a leaf spring 419 is connected to the front end portion of the base pin 452. The leaf springs 418 and 419 extend toward the central portion in parallel with the upper surface of the ceramic base 454, and are fixed in an insulating block 453 with less insulation arranged in the central portion. In the insulating block 453, the heater rod 414 is connected to the leaf spring 418. Similarly, in the insulating block 453, the heater rod 416 is connected to the leaf spring 419. The two heater rods 414 and 416 set as a center ring by the insulating block 453 extend vertically and are connected to the holding portion 412. The crystal 410 is embedded in the upper surface of the holding portion 412. In this structure, there are mechanical and electrical connection positions between the front end of the base pin 450 and the leaf spring 418, and mechanical and electrical connection positions between the front end of the base pin 452 and the leaf spring 419. In addition, there are mechanical and electrical connection positions between the heater rod 414 and the leaf spring 418 in the insulating block 453. Similarly, there are mechanical and electrical connection positions between the heater rod 416 and the leaf spring 419 in the insulating block 453. Therefore, there is a problem that the contact resistance at these connection positions is easy to change. Moreover, since the heater rods 414 and 416 become high temperature, the insulating block 453 itself also becomes high temperature. As a result, although it is originally a material with excellent insulation properties, poor insulation occurs in the insulating block 453. As a result, insulation breakdown occurs between the heater rods 414 and 416 in the insulating block 453, resulting in a problem that the resistance of the cathode mechanism as a whole changes.

[0048] Furthermore, in Comparative Example 2, contaminants accumulate on the insulating block 453 and electrically connect the heater rods 414 and 416 , so insulation breakdown occurs between the heater rods 414 and 416 , causing a problem in that the resistance of the entire cathode mechanism changes.

[0049] In contrast, in Embodiment 1, the holding portion 12, the pair of pillars 14, 16, and the pair of bases 18, 19 are formed of an integral structure based on the same material, so that the joint positions of mechanical joint and electrical joint can be eliminated. Thus, the change in contact resistance can be eliminated. In addition, although each end of the pair of pillars 14, 16 is connected to one of the separated bases 18, 19, since there is no insulating block, the accumulation of contaminants can be avoided. Thus, the insulation breakdown between the pillars 14, 16 can be eliminated, and the change in the resistance of the cathode mechanism as a whole can be eliminated.

[0050] As described above, according to Embodiment 1, the crystal 10 can be efficiently heated while achieving stability of the resistance of the cathode mechanism 222 and suppression of dielectric breakdown. By stabilizing the resistance of the cathode mechanism 222, temperature changes of the crystal 10 can be suppressed, and stable hot electrons can be emitted.

[0051] Figure 6 FIG. 1 is a diagram showing an example of the structure of the drawing device in Embodiment 1. Figure 1 In the drawing device 100, a drawing mechanism 150 and a control system circuit 160 are provided. The drawing device 100 is an example of a multi-electron beam drawing device. The drawing mechanism 150 includes an electron lens barrel 102 (multi-electron beam array) and a drawing chamber 103. An electron gun 201, an illumination lens 202, a forming 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 electron lens barrel 102. An XY table 105 is arranged in the drawing chamber 103. A sample 101 such as a mask blank coated with a resist, which is a drawing object substrate during drawing, is arranged on the XY table 105. The sample 101 includes an exposure mask when manufacturing a semiconductor device, or a semiconductor substrate (silicon wafer) for manufacturing a semiconductor device. A reflector 210 for measuring the position of the XY table 105 is also arranged on the XY table 105.

[0052] 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 also has a Wehnelt 224 (Wehnelt electrode) and an anode 226 (anode electrode). In addition, the anode 226 is controlled to be in a state of positive potential compared to the crystal 10 of the cathode mechanism 222, and extracts thermal electrons emitted from the crystal 10. For example, the anode 226 is grounded.

[0053] The control system circuit 160 includes a control computer 110, a memory 112, an electron gun power supply device 120, a deflection control circuit 130, digital / analog conversion (DAC) amplifier units 132 and 134, a table 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 table 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 the blanking aperture array mechanism 204 are connected to the deflection control circuit 130. The output of the DAC amplifier unit 132 is connected to the deflector 209. The output of the DAC amplifier unit 134 is connected to the deflector 208. The deflector 208 is composed of four or more electrodes, and is controlled by the deflection control circuit 130 via the DAC amplifier 134 for each electrode. 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 the 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 the principle of laser interference using the information of the reflected light.

[0054] Information input to and output from the control computer 110 and information in operation are stored in the memory 112 at all times.

[0055] An accelerating 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 in the electron gun power supply device 120 .

[0056] The cathode (-) side of the accelerating voltage power supply circuit 236 is connected to the wirings 50 and 52 at both poles of the cathode mechanism 222 in the electron column 102. The anode (+) side of the accelerating voltage power supply circuit 236 is grounded (grounded) via an ammeter 238 connected in series. In addition, the cathode (-) of the accelerating 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 Wehner 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 accelerating voltage power supply circuit 236 and the Wehner 224. In addition, the filament power supply circuit 231 allows current to flow between the wirings 50 and 52 at 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. The filament power and the cathode temperature T (heating temperature of the crystal 10) can be defined in a certain relationship, and the cathode temperature 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 by 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 Wiener 224.

[0057] In addition, drawing data is input from outside the drawing device 100 and stored in the storage device 140. The drawing data generally defines information of a plurality of graphic patterns used for drawing. Specifically, a graphic code, coordinates, size, etc. are defined for each graphic pattern.

[0058] Here, in Figure 6 , the configuration required to explain Embodiment 1 is described. The drawing device 100 may generally include other configurations required.

[0059] Figure 7 2 is a conceptual diagram showing the structure of the formed aperture array substrate 203 in Embodiment 1. Figure 7 In the example, holes (openings) 22 of p columns in the longitudinal direction (y direction) and q columns in the transverse direction (x direction) (p, q ≥ 2) are formed in a matrix at a predetermined arrangement pitch on the aperture array substrate 203. Figure 2For example, 512×512 rows 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 size. Alternatively, it can be a circle with the same diameter. The forming aperture array substrate 203 (beam forming mechanism) forms multiple beams 20. Specifically, multiple beams 20 are formed by allowing a portion of the electron beam 200 to pass through the multiple holes 22 respectively. In addition, the arrangement of the holes 22 is not limited to the following. Figure 7 For example, the holes in the kth column and the k+1th column in the longitudinal direction (y direction) can be arranged with a dimension a offset from each other in the transverse direction (x direction). Similarly, the holes in the k+1th column and the k+2th column in the longitudinal direction (y direction) can be arranged with a dimension b offset from each other in the transverse direction (x direction).

[0060] Figure 8 2 is a cross-sectional view showing the structure of the blanking aperture array mechanism 204 in Embodiment 1. Figure 8 As shown, the blanking aperture array mechanism 204 is configured with a semiconductor substrate 31 made of silicon or the like on a support platform 33. The central portion of the substrate 31 is cut from the back side, for example, to form a thinner diaphragm region 330 (first region) of thickness h. The area surrounding the diaphragm region 330 is formed into a peripheral region 332 (second region) of thickness H. The upper surface of the diaphragm region 330 and the upper surface of the peripheral region 332 are formed at the same height position, or substantially the same height position. The substrate 31 is held on the support platform 33 by the back side of the peripheral region 332. The central portion of the support platform 33 is open, and the position of the diaphragm region 330 is located in the area of ​​the opening of the support platform 33.

[0061] In the diaphragm region 330, Figure 7 The positions corresponding to the holes 22 of the aperture array substrate 203 are provided with through holes 25 (openings) for passing each of the multiple beams 20. In other words, in the diaphragm region 330 of the substrate 31, the multiple through holes 25 through which the corresponding beams of the multiple beams 20 of electron beams pass are formed in an array. Furthermore, multiple electrode pairs having two electrodes are respectively arranged at positions on the diaphragm region 330 of the substrate 31 that are opposite to each other with corresponding through holes 25 in the multiple through holes 25 interposed therebetween. Specifically, as Figure 8 As shown, on the diaphragm region 330, a group of control electrodes 24 and counter electrodes 26 for blanking deflection are arranged at positions near each through hole 25, sandwiching the corresponding through hole 25. In addition, a control circuit 41 (logic circuit) for applying a deflection voltage to the control electrode 24 for each through hole 25 is arranged inside the substrate 31 and near each through hole 25 on the diaphragm region 330. The counter electrode 26 for each beam is grounded.

[0062] An amplifier (an example of a switch circuit) not shown in the figure, such as a CMOS inverter circuit, is arranged in the control circuit 41. The output line (OUT) of the amplifier is connected to the control electrode 24. On the other hand, the ground potential is applied to the opposing electrode 26. One of the L (low) potential (for example, the ground potential) lower than the threshold voltage and the H (high) potential (for example, 1.5V) higher than the threshold voltage is applied to the input (IN) of the amplifier as a control signal. In Embodiment 1, in a state where the 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 the electric field generated by the potential difference with the ground potential of the opposing electrode 26, and is blocked by the limiting aperture substrate 206, thereby controlling the beam to be closed. On the other hand, in a state where the 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 opposing electrode 26 disappears, and the corresponding beam is not deflected, so it passes through the limiting aperture substrate 206, thereby controlling the beam to be open.

[0063] The control electrode 24 and the counter electrode 26 set blanks and deflects the corresponding beams of the multiple beams 20 independently through the potential switched by the amplifiers that constitute the corresponding switching circuits. In this way, the multiple blanking deflectors blank and deflect the corresponding beams of the multiple beams 20 after passing through the multiple holes 22 (openings) of the aperture array substrate 203.

[0064] Next, the operation of the drawing mechanism 150 in the drawing device 100 is described. The drawing mechanism 150 draws a pattern on the sample 101 using thermal electrons emitted from the electron gun 201. Specifically, it operates as follows. The electron beam 200 emitted from the electron gun 201 (electron emission source) illuminates the entire forming aperture array substrate 203 through the illumination lens 202. A plurality of rectangular holes 22 (openings) are formed in the forming aperture array substrate 203, and the electron beam 200 illuminates the area including all the plurality of holes 22. Each portion of the electron beam 200 irradiated to the position of the plurality of holes 22 passes through the plurality of holes 22 of the forming aperture array substrate 203, thereby forming a plurality of electron beams (multiple beams 20) in, for example, a rectangular shape. The multiple beams 20 pass through each corresponding blanking deflector (first deflector: individual blanking mechanism) of the blanking aperture array mechanism 204. The blanking deflector deflects the electron beams that pass through individually (performs blanking deflection).

[0065] The multi-beam 20 that has passed through the blanking aperture array mechanism 204 is reduced by the reduction lens 205 and moves toward the hole formed in the center of the limiting aperture substrate 206. Here, the electron beam in the multi-beam 20 that has been deflected by the blanking deflector of the blanking aperture array mechanism 204 is deviated from the hole in the center of the limiting aperture substrate 206 and is blocked by the limiting aperture substrate 206. On the other hand, the electron beam that has not been deflected by the blanking deflector of the blanking aperture array mechanism 204 is as shown in FIG. Figure 6 As shown, the hole in the center of the limiting aperture substrate 206 is passed. The opening / closing of the separate blanking mechanism is used to perform blanking control, thereby controlling the opening / closing of the beam. Moreover, for each beam, the beam formed from the time when the beam is turned on to the time when the beam is turned off and passes through the limiting aperture component 206 forms a beam emitted once. The multiple beams 20 passing through the limiting aperture substrate 206 are focused by the objective lens 207 to form a pattern image of the desired reduction ratio, and the beams passing through the limiting aperture substrate 206 (the entire multiple beams 20 after passing) are deflected in the same direction by the deflectors 208 and 209, and irradiated to each irradiation position on the sample 101 of each beam. The multiple beams 20 irradiated at one time are ideally arranged at the following pitch, which is the pitch obtained by multiplying the arrangement pitch of the multiple holes 22 of the forming aperture array substrate 203 by the above-mentioned desired reduction ratio.

[0066] Fig. 9 1 is a conceptual diagram for explaining an example of a drawing operation in Implementation Example 1. Fig. 9As shown, the drawing area 30 of the sample 101 is virtually divided into a plurality of rectangular strip areas 32 with a predetermined width, for example, in the y direction. First, the XY worktable 105 is moved and adjusted so that the irradiation area 34 that can be irradiated by the emission of the multi-photon electron beam 20 is located at the left end or further to the left of the first strip area 32, and the drawing is started. When drawing the first strip area 32, the XY worktable 105 is moved, for example, in the -x direction, so that the drawing is relatively performed in the x direction. The XY worktable 105 moves continuously, for example, at a constant speed. After the drawing of the first strip area 32 is completed, the worktable position is moved in the -y direction and adjusted so that the irradiation area 34 is relatively located at the right end or further to the right of the second strip area 32 in the y direction. This time, the XY worktable 105 is moved, for example, in the x direction, so that the drawing is similarly performed in the -x direction. In the third strip region 32, the drawing is done in the x direction, and in the fourth strip region 32, the drawing is done in the -x direction. By alternately changing the direction in this way, the drawing time can be shortened. However, the drawing is not limited to the case where the drawing is done by alternately changing the direction on one side. When drawing each strip region 32, the drawing can also be advanced in the same direction. In one emission, multiple beams are formed by passing through each hole 22 of the forming aperture array substrate 203, forming multiple emission patterns at most as many as the number of holes 22 formed in the forming aperture array substrate 203. In addition, in Fig. 9 In the example of FIG. 1 , each strip region 32 is drawn one by one, but the present invention is not limited thereto. It is also preferable to perform multiple drawing in which the same region is drawn multiple times. When performing multiple drawing, it is preferable to set the strip region 32 of each pass while shifting the position.

[0067] Fig.10 FIG. 1 is a diagram showing an example of a multi-beam irradiation area and a drawing target pixel in Embodiment 1. Fig.10 In the strip region 32, a plurality of control grids 27 (design grids) are set, for example, arranged in a grid shape at a beam size pitch of the multiple beams 20 on the surface of the sample 101. For example, it is preferable to set the arrangement pitch to about 10 nm. The multiple control grids 27 become the designed irradiation positions of the multiple beams 20. The arrangement pitch of the control grids 27 is not limited to the beam size, and can be configured with any size that can be controlled as the deflection position of the deflector 209 regardless of the beam size. Furthermore, a plurality of pixels 36 are set that are virtually divided into a grid shape with the same size as the arrangement pitch of the control grids 27 as the center. Each pixel 36 becomes the irradiation unit area of ​​each beam of the multiple beams. In Fig.10In the example, a case is shown where the drawing area of ​​the sample 101 is divided into a plurality of strip regions 32, for example, along the y direction with a width dimension substantially the same as the dimension of the irradiation area 34 (drawing area) that can be irradiated by irradiation of the multiple beams 20 at one time. The x-direction dimension of the irradiation area 34 can be defined by a value obtained by multiplying the inter-beam spacing in the x-direction of the multiple beams 20 by the number of beams in the x-direction. The y-direction dimension of the irradiation area 34 can be defined by a value obtained by multiplying the inter-beam spacing in the y-direction of the multiple beams 20 by the number of beams in the y-direction. In addition, the width of the strip region 32 is not limited thereto. Preferably, it is a dimension that is n times (n is an integer greater than 1) the irradiation area 34. In Fig.10 In the example, for example, the illustration of the multi-beam of 512×512 columns is omitted and represented as a multi-beam of 8×8 columns. Furthermore, in the irradiation area 34, a plurality of pixels 28 (beam drawing positions) that can be irradiated by emitting the multi-beam 20 once are shown. In other words, the spacing between adjacent pixels 28 is the spacing between each beam of the multi-beam in design. Fig.10 In the example of , a sub-irradiation area 29 is formed by an area surrounded by the inter-beam spacing. Fig.10 In the example of FIG. 1 , the case where each sub-irradiation region 29 is composed of 4×4 pixels is shown.

[0068] Fig.11 FIG. 1 is a diagram for explaining an example of a method for drawing multiple beams in Embodiment 1. Fig.11 In the figure, it is shown that Fig.10 A portion of the sub-irradiation area 29 drawn by each beam of the coordinates (1, 3), (2, 3), (3, 3), ..., (512, 3) in the third segment in the y direction among the multiple beams drawn by the strip-shaped area 32 shown in FIG. Fig.11 In the example of FIG. 1 , for example, the XY stage 105 depicts (exposes) four pixels while moving a distance of eight beam pitches. During the depiction (exposure) of the four pixels, the deflector 208 deflects the multi-beam 20 as a whole, so that the irradiation area 34 follows the movement of the XY stage 105, so that the relative position of the irradiation area 34 and the sample 101 does not deviate due to the movement of the XY stage 105. In other words, tracking control is performed. Fig.11 In the example of FIG. 1 , a tracking cycle is shown in which four pixels are drawn (exposed) for each shot while the pixel 36 to be irradiated with the beam is displaced in the y direction during movement of a distance of about eight beam pitches.

[0069] Specifically, the drawing mechanism 150 irradiates each corresponding beam of the turned-on beam in the multiple beams 20 to each control grid 27 at the following time, which is the 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 in the emission. The maximum irradiation time Ttr is preset. In fact, the time obtained by adding the setting time of beam deflection to the maximum irradiation time Ttr is the emission cycle, but the setting time of beam deflection is omitted here, and the maximum irradiation time Ttr is expressed as the emission cycle. In addition, at the end of one tracking cycle, the tracking control is reset, and the tracking position returns to the starting position of the next tracking cycle.

[0070] In addition, since the depiction of the first pixel column from the right of each sub-irradiation area 29 is completed, after the tracking is reset, in the next tracking cycle, the deflector 209 is first deflected so that the control grid 27 of the first segment from the bottom and the second pixel from the right of each sub-irradiation area 29 is aligned (shifted to) the depiction position of each corresponding beam.

[0071] As described above, in the same tracking cycle, the irradiation area 34 is controlled by the deflector 208 to be in the same relative position with respect to the sample 101, and each emission is performed while the control grid 27 (pixel 36) is shifted by 1 at a time by the deflector 209. After the tracking cycle ends, the tracking position of the irradiation area 34 is returned, and then the irradiation area 34 is returned to the tracking position. Fig.10 As shown in the lower part of , for example, the first emission position is made consistent with the position shifted by 1 control grid (1 pixel), and each emission is performed while performing the subsequent tracking control while shifting 1 control grid (1 pixel) by the deflector 209. In the depiction of the strip region 32, by repeating this action, the position of the irradiation region 34 is sequentially moved within the range of the irradiation regions 34a to 34o, thereby advancing the depiction of the strip region.

[0072] Furthermore, which beam of the multiple 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 set to 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 also drawn by a beam different from the above beam. In this way, in n tracking operations, all pixels in an area of ​​n×n pixels are drawn by drawing every n pixels by different beams. The same operation is also performed on other n×n pixel sub-irradiation areas 29 in the irradiation area of ​​the multiple beams at the same time, and the drawing is also performed.

[0073] As described above, since the resistance of the cathode mechanism 222 is stable, it is possible to emit a stable electron beam 200. As a result, high-precision drawing can be performed.

[0074] The embodiments have been described above with reference to specific examples, but the present invention is not limited to these specific examples.

[0075] In addition, although the description of the device configuration and control method of the parts not directly necessary in the description of the present invention is omitted, the necessary device configuration and control method can be appropriately selected and used. For example, although the description of the control unit configuration for controlling the rendering device 100 is omitted, it is of course possible to appropriately select the necessary control unit configuration and use it.

[0076] In addition, all cathode mechanisms of electron guns, electron guns, and electron beam drawing devices that include the elements of the present invention and can be appropriately designed and modified by those skilled in the art are included in the scope of the present invention.

[0077] Other advantages and modifications can be easily thought of by those skilled in the art. Therefore, the present invention is not limited to the specific details and embodiments described above. Therefore, various modifications can be made without departing from the scope of the main idea of ​​the invention. The embodiment and its variations are included in the scope and main idea of ​​the invention, and are also included in the invention described in the claims and its equivalent scope.

Claims

1. A cathode mechanism of an electron gun, characterized in that: have: A crystal, which is heated to emit hot electrons from one end face; a holding portion that holds the crystal in a state where the one end face is exposed and at least a portion of other faces of the crystal is covered; The first support and the second support support the holding portion and extend while maintaining the same cross-sectional dimensions. a first base portion, fixing the first support column; as well as a second base, fixing the second support, The holding portion, the first support and the second support, the first base and the second base are formed by an integral structure based on the same material, and the crystal is heated by passing an electric current through the integral structure. The integrated structure is obtained by processing a base material having a cylindrical shape standing upright in the center of a plate-shaped base portion. The first support and the second support have a cross-sectional structure in which three sides are straight lines and one side is a curve. The cross-sectional dimensions of the first base and the second base are greater than the cross-sectional dimensions of the first support and the second support.

2. The cathode mechanism of an electron gun according to claim 1, wherein: The crystal is formed in at least one of a cylindrical shape and a truncated cone shape.

3. The cathode mechanism of an electron gun according to claim 1, wherein: The first support and the second support function as a heater for heating the crystal via the holding portion.

4. The cathode mechanism of an electron gun according to claim 1, wherein: The crystal orientations in the one end surface are the same.

5. The cathode mechanism of the electron gun according to claim 1, characterized in that: As a material of the integral structure, one of graphite, tantalum, tungsten and iridium is used.

6. The cathode mechanism of an electron gun according to claim 1, wherein: A space of the same width is formed continuously from the back surface of the holding portion between the first support and the second support and between the first base and the second base.

7. An electron gun, characterized in that: have: The cathode mechanism of the electron gun according to claim 1; and The anode electrode is controlled to be in a state of a positive potential compared to the crystal, and is used to extract thermal electrons emitted from the crystal.

8. An electron beam drawing device, characterized in that: have: The electron gun according to claim 7; and The drawing mechanism draws a pattern on a sample using thermal electrons emitted from the electron gun.

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