Electron gun component, electron gun, and electron beam device

Abstract

An electron gun component includes an electron emission component 10 that emits electrons, and a suppression electrode 50 having an opening 50a through which the electron emission component 10 is inserted, wherein the ratio of the sum of the distance D between the center C1 of the area A occupied by the electron emission component and the center C2 of the smallest face B among the opening face 50b of the opening 50a and the cross section, and the radius R1 of the area A of the electron emission component, to the radius R2 of the smallest face B ([((D+R1) / R2]x100) is 80.0% or less.

Description

Technical Field

[0001] This disclosure relates to an electron gun component, an electron gun, an electron beam device, etc. Background Technology

[0002] Electron guns are used in electron beam devices such as electron microscopes and semiconductor inspection equipment. An electron gun comprises an electron gun component and an extraction electrode. The electron gun component includes an electron emitting component for emitting electrons and a suppression electrode with an opening. Various structures of electron guns have been studied (for example, see Patent Document 1 below).

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2007-250491 Summary of the Invention

[0004] The problem the invention aims to solve In the electron gun assembly, there is a case where the electron emission component is inserted into the opening of the suppression electrode. In this situation, if the electron emission component is close to the suppression electrode in the opening of the suppression electrode, a discharge may occur between the electron emission component and the suppression electrode, thereby hindering electron emission.

[0005] One aspect of this disclosure aims to provide an electron gun component capable of effectively emitting electrons. Another aspect aims to provide an electron gun incorporating such an electron gun component. Yet another aspect aims to provide an electron beam device incorporating such an electron gun.

[0006] Technical means to solve the problem [1] An electron gun component comprising: an electron emission component for emitting electrons, and a suppression electrode having an opening, wherein the electron emission component is inserted into the opening, and the sum of the distance D between the center of the region occupied by the electron emission component and the center of the minimum surface in the opening face and the cross-section of the opening, and the radius R1 of the region of the electron emission component, is 80.0% or less relative to the radius R2 of the minimum surface ([(D+R1) / R2]×100).

[0007] [2] According to the electron gun component described in [1], the ratio of the distance D to the radius R2 ([D / R2]×100) is less than 30.0%.

[0008] [3] According to the electron gun component described in [1] or [2], the ratio of the radius R1 to the radius R2 ([R1 / R2]×100) is 50.0% or less.

[0009] [4] The distance D of the electron gun component according to any one of [1] to [3] is 60 μm or less.

[0010] [5] The electron gun component according to any one of [1] to [4], wherein the radius R1 is 125 μm or less and the radius R2 is 500 μm or less.

[0011] [6] An electron gun comprising: an electron gun component as described in any one of [1] to [5], and an output electrode facing the suppression electrode.

[0012] [7] An electron beam device comprising the electron gun described in [6].

[0013] The effects of the invention According to one aspect of this disclosure, an electron gun component capable of effectively emitting electrons can be provided. According to another aspect of this disclosure, an electron gun incorporating such an electron gun component can be provided. According to yet another aspect of this disclosure, an electron beam device incorporating such an electron gun can be provided. Attached Figure Description

[0014] [ Figure 1 ] Figure 1 An end view schematically illustrating an example of an electron gun component.

[0015] [ Figure 2 ] Figure 2 This is a diagram illustrating an example of observing the opening surface and the smallest surface in the cross-section of the suppression electrode opening.

[0016] [ Figure 3 ] Figure 3 This is another example of observing the opening surface and the smallest surface in the cross-section of the suppression electrode opening. Detailed Implementation

[0017] The numerical range "above A" refers to A and the range exceeding A. The numerical range "below A" refers to A and the range less than A. In the numerical ranges described in stages in this specification, the upper or lower limit of a certain stage's numerical range can be arbitrarily combined with the upper or lower limits of the numerical ranges of other stages. In the numerical ranges described in this specification, the upper or lower limit of the numerical range can be replaced with the values ​​shown in the embodiments. "A or B" may include either A or B, or both. The materials illustrated in this specification can be used alone or in combination of two or more.

[0018] The electron gun component according to this embodiment includes an electron emission component that emits electrons and a suppression electrode with an opening, wherein the electron emission component is inserted into the opening of the suppression electrode. In the electron gun component according to this embodiment, the sum of the distance D between the center of the region A occupied by the electron emission component and the center of the minimum surface B of the suppression electrode (hereinafter, depending on the situation, it is simply referred to as "the minimum surface B of the suppression electrode") on the opening surface of the suppression electrode opening and the minimum surface B of the cross section, and the radius R1 of the region A, is 80.0% or less relative to the radius R2 of the minimum surface B of the suppression electrode, in the ratio X1 (X1=[(D+R1) / R2]×100).

[0019] According to the inventors' findings, in an electron gun component having an electron emission component inserted into the opening of a suppression electrode, the electron emission component and the suppression electrode may approach each other in the opening of the suppression electrode due to factors such as misalignment of the component's mounting position during manufacturing, residual stress in the component, or gravity applied to the component. In this regard, the proportion X1 in the electron gun component according to this embodiment can be used as an indicator of the degree of proximity between the electron emission component and the suppression electrode in the opening of the suppression electrode. According to the electron gun component according to this embodiment, since the proportion X1 is 80.0% or less, the proximity between the electron emission component and the suppression electrode in the opening of the suppression electrode can be suppressed. Therefore, discharges between the electron emission component and the suppression electrode can be suppressed, thereby enabling efficient electron emission. The electron gun component according to this embodiment can be used as a Schottky electron gun component.

[0020] The electron gun component according to this embodiment includes an electron emission component that emits electrons. The electron emission component can emit electrons by heating, by applying an electric field, or by both heating and applying an electric field. The electron emission component may have a front end for emitting electrons. The direction of electron emission can be any of the following: vertically upward, vertically downward, horizontal, inclined from the vertical, inclined from the horizontal, etc. The shape of the electron emission component is not particularly limited; for example, it can be a columnar component extending along the electron emission direction. Examples of cross-sectional shapes (cross-sections perpendicular to the electron emission direction) in the electron emission component include: circular (perfect circle, ellipse, etc.), polygonal (triangle, quadrilateral, pentagon, hexagon, etc.). The front end of the electron emission component can be flat or pointed (for example, it can be tapered and tapered). The length of the electron emission component (length in the electron emission direction) can be 100–5000 μm, 500–4000 μm, or 1000–3000 μm.

[0021] Examples of constituent elements for electron emission components include tungsten, iridium, and lanthanides. Lanthanides include lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Materials used in electron emission components include tungsten (e.g., W(100), W(310) tungsten single crystals), lanthanide-containing borides (LaB6 (e.g., LaB6 single crystals), CeB6 (e.g., CeB6 single crystals), HfC (e.g., HfC single crystals), iridium, and compounds containing lanthanides (IrCe compounds, IrLa compounds, etc.). IrCe compounds include Ir2Ce, Ir3Ce, Ir7Ce2, and Ir5Ce. The constituent materials of the electron emission component can be a single type or a combination of two or more types.

[0022] The electron emission component is inserted into and passes through the opening (through hole) of the suppression electrode. That is, the electron emission component extends from one opening surface of the suppression electrode opening to the other opening surface.

[0023] The electron gun component according to this embodiment includes a suppression electrode with an opening (through hole), and an electron emitting component is inserted through the opening. The suppression electrode can be used to suppress electron emission from a portion of the electron emitting component other than the front end (e.g., the side of the electron emitting component), and can also be used to suppress electron emission from other components such as the filament described later. Examples of shapes for the opening surface and cross-section of the suppression electrode include: circular (perfect circle, ellipse, etc.), polygonal (triangle, quadrilateral, pentagon, hexagon, etc.).

[0024] The electron gun component according to this embodiment may include an electron source having an electron emission component and a suppression electrode. The electron source may have components other than the electron emission component. Examples of components other than the electron emission component include: a diffusion source (storage unit), a filament, and a support component.

[0025] The diffusion source is in contact with the electron emission component. The diffusion source can be positioned on the outer periphery of the electron emission component between its front and base ends, or on the outer periphery of the central portion of the electron emission component in the electron emission direction. The material of the diffusion source is not particularly limited; examples include zirconium oxide (e.g., ZrO) and calcium oxide (e.g., CaO).

[0026] The filament is connected to the electron emission component, or it can be connected to the electron emission component via a conductive component. The filament can be used to heat the electron emission component. The electron source can have a single filament or multiple filaments. Materials with heat resistance and conductivity can be used as the constituent materials of the filament. Examples of constituent elements of the filament include: tungsten, rhenium, molybdenum, platinum, aluminum, silicon, and potassium. The filament can be a tungsten filament or a tungsten-rhenium (tungsten-rhenium alloy) filament.

[0027] A support member supports the filament. The support member may have an insulating component and a pair of terminals, with the terminals spaced apart from each other through the insulating component. In this case, one end of the filament can be connected to one terminal, and the other end of the filament can be connected to the other terminal.

[0028] The electron gun component according to this embodiment may include a first power source for heating (electrically heating) an electron emitting component and / or a filament. The first power source is capable of supplying current to the electron emitting component for heating the electron emitting component and supplying current to the filament for heating the filament. The first power source may be electrically connected to the electron emitting component via the filament, or via terminals of a support component and the filament, or via terminals of the support component and the filament.

[0029] The electron gun component according to this embodiment may include a second power supply (bias power supply, suppression power supply) for applying voltage to the suppression electrode. The second power supply is connected to the suppression electrode and can output a negative voltage to the suppression electrode.

[0030] Figure 1 An end view schematically illustrating an example of an electron gun component. Figure 1 The electron gun component 100 includes an electron emission component 10, a diffusion source (storage) 20, a filament 30, a support component 40, and a suppression electrode 50.

[0031] The electron emitting component 10 is a columnar component extending along the electron emission direction and has a front end 10a for emitting electrons. The diffusion source 20 is disposed on the outer periphery of the central portion of the electron emitting component 10 in the electron emission direction. The filament 30 has a shape formed by bending a straight filament, and the base end of the electron emitting component 10 is connected to the bent portion of the filament.

[0032] The support member 40 has an insulating member (insulator) 42 and a pair of straight terminals 44. The pair of terminals 44 pass through the insulating member 42 at intervals. One end of the filament 30 is connected to one of the terminals 44, and the other end of the filament 30 is connected to the other terminal of the pair of terminals 44. A first power source (not shown) for heating the electron emission member 10 is electrically connected to the electron emission member 10 through the pair of terminals 44 and the filament 30.

[0033] The suppression electrode 50 has a cylindrical portion 52, a connecting portion 54, a tapered portion 56, and a front end portion 58. The cylindrical portion 52 is a cylindrical body with an internal space, and is connected to an insulating member 42 housed in the internal space via the connecting portion 54 disposed in the internal space. The tapered portion 56 is connected to the end of the cylindrical portion 52 in the electron emission direction. The tapered portion 56 is tapered in diameter along the electron emission direction. The front end portion 58 is connected to the end of the tapered portion 56 in the electron emission direction. The front end portion 58 is flat and has an opening 50a formed in the center for the electron emission member 10 to pass through. The opening 50a has an opening surface 50b on the front end 10a side of the electron emission member 10, which is the smallest surface B in the opening surface and cross-section of the opening 50a. A second power source (not shown) for applying voltage to the suppression electrode 50 is connected to the suppression electrode 50.

[0034] In the electron gun component according to this embodiment, from the viewpoint of suppressing the electron emission component to approach the suppressing electrode for efficient electron emission, the ratio X1 (X1=[(D+R1) / R2]×100) of the minimum surface B of the opening surface and cross-section (cross-section perpendicular to the opening direction of the opening) of the suppressing electrode opening is 80.0% or less, relative to the radius R1 of the minimum surface B of the suppressing electrode. From the viewpoint of easily suppressing the electron emission component to approach the suppressing electrode for efficient electron emission, the ratio X1 can be 75.0% or less, 70.0% or less, 65.0% or less, 60.0% or less, 55.0% or less, 50.0% or less, 45.0% or less, 40.0% or less, or 35.0% or less. From the perspective of easily suppressing excess electron emission that may become a source of noise, the proportion X1 can be 0% or more, greater than 0%, 5.0% or more, 10.0% or more, 15.0% or more, 20.0% or more, 25.0% or more, 30.0% or more, 35.0% or more, 40.0% or more, 45.0% or more, 50.0% or more, or 55.0% or more. Based on these viewpoints, the scale X1 can be 0% or more to 80.0%, 0% or more to 60.0%, 0% or more to 50.0%, 0% or more to 40.0%, 0% or more to 35.0%, greater than 0% and less than 80.0%, greater than 0% and less than 60.0%, greater than 0% and less than 50.0%, greater than 0% and less than 40.0%, greater than 0% and less than 35.0%, 30.0 to 80.0%, 30.0 to 60.0%, 30.0 to 50.0%, 30.0 to 40.0%, or 30.0 to 35.0%. As shown in the embodiments described later, the scale X1 can be calculated by obtaining the distance D, radius R1, and radius R2 using an observation image of the minimum surface B of the suppression electrode. An observation image can be obtained by aligning the focal point of the minimum surface B of the suppression electrode from the front end side of the electron emission component in a direction perpendicular to the minimum surface B of the suppression electrode. An image of the minimum surface B can be obtained regardless of the opening direction of the suppression electrode opening. The minimum face B is the face with the smallest diameter. When the shape of the opening face or cross-section is not a perfect circle, it is the face with the smallest radius of the largest inscribed circle. When the shape and size of the opening remain unchanged in the opening direction, the opening face (opening end) on the front end side of the electron emission component in the opening can be used as the minimum face B.

[0035] On the smallest surface B of the suppression electrode, the radius R1 of the region A occupied by the electron-emitting component can be within the following ranges. From the viewpoints of easily suppressing proximity between the electron-emitting component and the suppression electrode, easily increasing electron emission brightness, easily suppressing positional changes due to the weight of the electron-emitting component, or easily concentrating the electric field and emitting electrons, the radius R1 can be 200 μm or less, 180 μm or less, 150 μm or less, 125 μm or less, 120 μm or less, 100 μm or less, 90.0 μm or less, 80.0 μm or less, 70.0 μm or less, or 65.0 μm or less. From the viewpoint of easily suppressing damage due to impact, the radius R1 can be 1.0 μm or more, 5.0 μm or more, 10.0 μm or more, 20.0 μm or more, 30.0 μm or more, 40.0 μm or more, 50.0 μm or more, or 60.0 μm or more. Based on these viewpoints, the radius R1 can be 1.0–200 μm, 1.0–100 μm, 1.0–80 μm, 10.0–200 μm, 10.0–100 μm, 10.0–80.0 μm, 30.0–200 μm, 30.0–100 μm, or 30.0–80.0 μm. When the shape of region A is not a perfect circle, the radius R1 is the minimum circumcircle radius of region A (see below). Figure 3 ).

[0036] Based on the ratio to R1 described later, the radius R2 of the minimum surface B of the suppression electrode can be within the following ranges. From the viewpoint of easily suppressing excess electron emission that may be a cause of noise, the radius R2 can be less than 1000 μm, less than 900 μm, less than 800 μm, less than 700 μm, less than 600 μm, less than 500 μm, less than 400 μm, less than 300 μm, less than 250 μm, or less than 200 μm. From the viewpoint of easily suppressing electron emission components and the suppression electrode, the radius R2 can be more than 10 μm, more than 30 μm, more than 50 μm, more than 80 μm, more than 100 μm, more than 120 μm, more than 150 μm, more than 180 μm, or more than 200 μm. Based on these viewpoints, the radius R2 can be 10–1000 μm, 10–500 μm, 10–300 μm, 50–1000 μm, 50–500 μm, 50–300 μm, 100–1000 μm, 100–500 μm, or 100–300 μm. When the shape of the minimum surface B of the suppression electrode is not a perfect circle, the radius R2 is the radius of the maximum inscribed circle of the minimum surface B (see below). Figure 3 ).

[0037] Based on the ratio to R1 described later, the distance D between the center of the region A occupied by the electron emission component and the center of the minimum surface B of the suppression electrode can be within the following ranges. From the viewpoint of facilitating the proximity of the electron emission component to the suppression electrode, the distance D can be 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 15 μm or less, 10 μm or less, 5 μm or less, or 3 μm or less. From the viewpoint of improving manufacturing yield, the distance D can be 0 μm or more, greater than 0 μm, 1 μm or more, 3 μm or more, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. Based on these viewpoints, the distance D can be greater than or equal to 0 μm and less than 500 μm, greater than or equal to 0 μm and less than 80 μm, greater than or equal to 0 μm and less than 30 μm, greater than or equal to 0 μm and less than 15 μm, greater than or equal to 0 μm and less than 10 μm, greater than or equal to 0 μm and less than 500 μm, greater than or equal to 0 μm and less than 80 μm, greater than or equal to 0 μm and less than 30 μm, greater than or equal to 0 μm and less than 15 μm, greater than or equal to 0 μm and less than 10 μm, 1–500 μm, 1–80 μm, 1–30 μm, 1–15 μm, or 1–10 μm. The distance D can be adjusted by the relative position of the center of region A to the opening of the suppression electrode. For example, the distance D can be adjusted by the mounting position of each component during the manufacture of the electron gun component (e.g., the fixed position of the filament relative to the terminal of the support component). Furthermore, the distance D can also be adjusted by electrically heating the electron emission component, filament, etc.

[0038] The ratio X2 of distance D to radius R1 (X2 = [D / R1] × 100) can be within the following ranges. From the viewpoint of easily suppressing electron emission by bringing the component close to the suppression electrode, thus facilitating efficient electron emission, the ratio X2 can be 100% or less, 90.0% or less, 80.0% or less, 70.0% or less, 60.0% or less, 50.0% or less, 40.0% or less, 30.0% or less, 20.0% or less, or 10.0% or less. From the viewpoint of improving manufacturing yield, the ratio X2 can be 0% or more, greater than 0%, 1.0% or more, 3.0% or more, 5.0% or more, 10.0% or more, 20.0% or more, 30.0% or more, 40.0% or more, 50.0% or more, 60.0% or more, or 70.0% or more. Based on these viewpoints, the ratio X2 can be 0% to 100%, 0% to 80.0%, 0% to 40.0%, 0% to 20.0%, 0% to 10.0%, greater than 0% and less than 100%, greater than 0% and less than 80.0%, greater than 0% and less than 40.0%, greater than 0% and less than 20.0%, greater than 0% and less than 10.0%, 3.0 to 100%, 3.0 to 80.0%, 3.0 to 40.0%, 3.0 to 20.0%, or 3.0 to 10.0%.

[0039] The ratio X3 of distance D to radius R2 (X3 = [D / R2] × 100) can be within the following ranges. From the viewpoint of easily suppressing electron emission by bringing the component close to the suppression electrode, thus facilitating efficient electron emission, the ratio X3 can be 50.0% or less, 40.0% or less, 30.0% or less, 25.0% or less, 20.0% or less, 15.0% or less, 10.0% or less, 8.0% or less, 6.0% or less, 5.0% or less, 3.0% or less, or 2.0% or less. From the viewpoint of improving manufacturing yield, the ratio X3 can be 0% or more, greater than 0%, 1.0% or more, 2.0% or more, 3.0% or more, 5.0% or more, 6.0% or more, 8.0% or more, 10.0% or more, 15.0% or more, 20.0% or more, or 25.0% or more. Based on these viewpoints, the ratio X3 can be above 0% and below 50.0%, above 0% and below 30.0%, above 0% and below 15.0%, above 0% and below 8.0%, above 0% and below 5.0%, above 0% and below 50.0%, above 0% and below 30.0%, above 0% and below 15.0%, above 0% and below 8.0%, above 0% and below 5.0%, 1.0–50.0%, 1.0–30.0%, 1.0–15.0%, 1.0–8.0%, or 1.0–5.0%.

[0040] The ratio X4 of radius R1 to radius R2 (X4 = [R1 / R2] × 100) can be within the following ranges. From the viewpoint of easily suppressing the proximity of the electron-emitting component to the suppression electrode, thus facilitating efficient electron emission, or from the viewpoint of easily concentrating the electric field and emitting electrons, the ratio X4 can be 80.0% or less, 70.0% or less, 60.0% or less, 50.0% or less, 40.0% or less, or 35.0% or less. From the viewpoint of easily suppressing damage caused by impact, the ratio X4 can be greater than 0%, 1.0% or more, 5.0% or more, 10.0% or more, 15.0% or more, 20.0% or more, 25.0% or more, or 30.0% or more. Based on these viewpoints, the ratio X4 can be greater than 0% and less than 80.0%, greater than 0% and less than 60.0%, greater than 0% and less than 40.0%, 10.0–80.0%, 10.0–60.0%, 10.0–40.0%, 20.0–80.0%, 20.0–60.0%, or 20.0–40.0%.

[0041] Figure 2 This diagram illustrates an example of observing the opening surface and the smallest surface in the cross-section of the suppression electrode opening. Figure 2 In the diagram, region A, occupied by the electron emission component, exists on the minimum surface B of the suppression electrode. Region A and minimum surface B are both circular. Region A has a center C1 and a radius R1. Minimum surface B has a center C2 and a radius R2. The distance between centers C1 and C2 is D.

[0042] Figure 3 This is another example of observing the opening surface and the smallest surface in the cross-section of the suppression electrode opening. Figure 3 and Figure 2 The difference is that region A and the minimum face B are not circular but polygonal in shape. When region A and the minimum face B are polygonal, as shown... Figure 3 As shown, the center C1 and radius R1 of region A are used, along with the center and radius of the smallest circumcircle A' of region A. The center C2 and radius R2 of the smallest face B are used, along with the center and radius of the largest incircle B' of the smallest face B.

[0043] exist Figure 2 and Figure 3 In the example, the ratio X1 represents the ratio of the sum of distance D and radius R1 to radius R2 ([(D+R1) / R2]×100). In this case, the larger the distance D and / or radius R1, the larger the sum of distance D and radius R1, the closer region A1 is to the inner edge of the suppression electrode located on the outer periphery of the minimum surface B, and therefore the easier it is to generate discharge. That is, when the electron emission component is deviated from the center of the minimum surface B, and / or when the size of the electron emission component in the radial direction of the minimum surface B is large, the electron emission component is close to the suppression electrode, and therefore it is easy to generate discharge.

[0044] The electron gun according to this embodiment includes the electron gun components according to this embodiment and a lead-out electrode facing the suppression electrode. The electron gun according to this embodiment can be used as a Schottky electron gun.

[0045] The lead-out electrode can be used to apply an electric field for emitting electrons from the electron emission component. The lead-out electrode may have an opening (through-hole) through which electrons emitted from the electron emission component pass. The lead-out electrode may have a positive potential relative to a suppression power source with a negative potential.

[0046] The electron gun according to this embodiment may include a third power supply for applying voltage to the lead-out electrodes. The third power supply is connected to the lead-out electrodes and can output a positive voltage to the lead-out electrodes.

[0047] The electron gun according to this embodiment may have an accelerating electrode positioned opposite the suppressing electrode on the side opposite to the extracting electrode. That is, the extracting electrode is disposed between the suppressing electrode and the accelerating electrode. The accelerating electrode can be used to accelerate electrons emitted from the electron emission component. The accelerating electrode may have an opening (through-hole) through which electrons emitted from the electron emission component pass. The accelerating electrode may have a positive potential relative to the suppressing power supply having a negative potential.

[0048] The electron gun component according to this embodiment may include a fourth power supply for applying voltage to the accelerating electrode. The fourth power supply is connected to the accelerating electrode and can output a positive voltage to the accelerating electrode.

[0049] The electron beam apparatus according to this embodiment includes the electron gun according to this embodiment. Examples of electron beam apparatus include: X-ray generating apparatus, electron microscope, semiconductor manufacturing apparatus, analytical apparatus (inspection apparatus: for example, electron probe microanalyzer), and processing apparatus (for example, electron beam evaporation apparatus).

[0050] Example The present disclosure will be described in more detail below using examples, but the present disclosure is not limited to the following examples.

[0051] <Fabrication of Electron Gun Components> Obtain through the following steps Figure 1 The electron gun component 100 is shown. The electron emission direction of the electron gun component 100 is adjusted to be vertical and upward.

[0052] First, a filament 30 is obtained by bending a straight filament (material: tungsten, cross-sectional shape: circular, diameter: 127 μm). Next, a support member 40 is prepared, having an insulating component 42 (material: alumina) and a pair of terminals 44 (material: Kova alloy, terminal spacing: 5.59 mm). Then, one end of the filament 30 is welded to one of the terminals 44, and the other end of the filament 30 is welded to the other terminal of the pair of terminals 44.

[0053] As the electron emission component 10, a tungsten single crystal cylinder is prepared (cylinder length direction: (100) crystal orientation of the tungsten single crystal, radius: 63.5 μm, length: 2000 μm). Next, the base end side of the electron emission component 10 is welded to the side of the bent portion of the filament 30. Then, in order to release stress, the electron emission component 10 and the filament 30 are heated by energizing a pair of terminals 44 of the support component 40.

[0054] The front end 10a of the electron emission component 10 is sharpened by electrolytic polishing. Then, a zirconium oxide (ZrO) diffusion source (reservoir) 20 is formed on the outer periphery of the central part of the electron emission component 10 in the electron emission direction.

[0055] A suppression electrode 50 is prepared, comprising a cylindrical portion 52, a connecting portion 54, a conical portion 56, and a front end portion 58. Next, an electron emission component 10 is inserted into the opening 50a of the suppression electrode 50, and the support component 40 is connected to the suppression electrode 50 via the connecting portion 54. The length of the portion of the electron emission component 10 protruding from the opening surface 50b is 250 μm. Through the above steps, an electron gun component 100 is obtained in which the relative relationship between the electron emission component 10 and the opening 50a of the suppression electrode 50 satisfies the relative relationship shown in Table 1. The relative relationship between the electron emission component 10 and the opening 50a of the suppression electrode 50 is adjusted by adjusting the mounting positions of each component during the manufacture of the electron gun component 100 (e.g., the fixed position of the filament 30 relative to the terminal 44 of the support component 40) and by heating the electron emission component 10 and the filament 30 by applying electricity.

[0056] <Observation of the suppression electrode opening> Using a scanning electron microscope (SEM), an image is obtained by aligning the front end 10a of the electron emitting component 10 with the focal point of the opening 50b in a direction perpendicular to the opening 50b of the suppression electrode 50. For the image analysis step, [the following steps are performed]. Figure 3 The following explanation is provided. Using image analysis software, the region A occupied by the electron emission component on the minimum surface B of the suppression electrode, as well as the minimum surface B of the suppression electrode, are determined. The center and radius of the smallest circumcircle of region A are taken as the center C1 and radius R1 of region A. The center and radius of the largest incircle of the minimum surface B are taken as the center C2 and radius R2 of the minimum surface B.

[0057] The radius R1 is 63.5 μm, and the radius R2 is 200 μm. The distance D between the center C1 of the measurement area A and the center C2 of the smallest surface B is shown in Table 1. Table 1 also shows the calculated results of the ratios of distance D to radius R1 relative to radius R2: X1 (X1 = [(D+R1) / R2]×100), X2 (X2 = [D / R1]×100), and X3 (X3 = [D / R2]×100). The ratio of radius R1 to radius R2, X4 (X4 = [R1 / R2]×100), is 31.8%.

[0058] <Evaluation: Electron emission test> A Schottky electron gun was fabricated by connecting the lead-out electrode, the accelerating electrode, and various power supplies (power supplies 1 to 4 mentioned above) to the electron gun component 100. Using this Schottky electron gun, electron emission was performed for 120 hours under the following conditions. The condition where electron emission could be sustained for 120 hours was classified as "A," and the condition where electron emission could not be sustained for 120 hours due to discharge, etc., was classified as "B." The results are shown in Table 1.

[0059] Vacuum degree: 2.53×10 -8 Pa Electron emission component temperature: 1800K Bias voltage (voltage between the electron emission component and the suppression electrode): -300V Power supply voltage: 4700V Lead-out electrode opening diameter: 0.5mm Distance between the front end of the electron emission component and the opening of the lead-out electrode: 0.75mm Accelerator power supply voltage: 4700V Accelerating electrode opening diameter: 2.0mm Distance between the lead-in electrode and the accelerating electrode: 10mm [Table 1]

[0060] Symbol Explanation 10... Electron emission component, 10a... Front end, 20... Diffusion source, 30... Filament, 40... Support component, 42... Insulating component, 44... Terminal, 50... Suppression electrode, 50a... Opening, 50b... Opening surface, 52... Cylindrical part, 54... Connecting part, 56... Conical part, 58... Front end part, 100... Electron gun component, A... Region, A'... Circumcircle, B... Minimum surface, B'... Inscribed circle, C1, C2... Center, D... Distance, R1, R2... Radius.

Claims

1. An electron gun component comprising: an electron emitting component for emitting electrons, and a suppression electrode having an opening. The electron emission component is inserted into the opening. On the smallest surface of the opening and the cross-section of the opening, the sum of the distance D between the center of the area occupied by the electron emission component and the center of the smallest surface, and the radius R1 of the area of ​​the electron emission component, relative to the radius R2 of the smallest surface ([(D+R1) / R2]×100) is less than 80.0%.

2. The electron gun component according to claim 1, wherein the ratio of the distance D to the radius R2 ([D / R2]×100) is 30.0% or less.

3. The electron gun component according to claim 1, wherein the ratio of radius R1 to radius R2 ([R1 / R2]×100) is 50.0% or less.

4. The electron gun component according to claim 1, wherein the distance D is less than 60 μm.

5. The electron gun component according to claim 1, wherein the radius R1 is less than 125 μm and the radius R2 is less than 500 μm.

6. An electron gun comprising: an electron gun component according to any one of claims 1 to 5, and an output electrode opposite to the suppression electrode.

7. An electron beam device comprising the electron gun of claim 6.

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