Electron gun and vapor deposition apparatus

Abstract

To provide an electron gun that can improve the focusing ability of the electron beam. [Solution] The electron gun 110 includes a filament 10, a Wehnert 20 for focusing the electron beam EB emitted from the filament 10, and an anode 30 for accelerating the electron beam EB emitted from the filament 10. The Wehnert 20 has a first portion 24a and a second portion 24b. The filament 10 is positioned between the first portion 24a and the second portion 24b. The anode 30 is located in a first direction (+Z direction) of the first portion 24a. In the first direction, the distance D1 between the first portion 24a and the anode 30 is smaller than the distance between the second portion 24b and the anode 30.

Description

Technical Field

[0001] The present invention relates to an electron gun and a vapor deposition apparatus.

Background Art

[0002] As a method for forming a thin film on a semiconductor substrate, a lens, or the like, an electron beam evaporation method is known. The electron beam evaporation method is a method of irradiating an electron beam emitted from an electron gun in a vacuum onto an evaporation material, heating and evaporating the evaporation material, and depositing the evaporation material on a semiconductor substrate or the like to form a thin film.

[0003] For example, Patent Document 1 discloses an electron gun including a filament, a Wehnelt that converges an electron beam emitted from the filament, and an anode that accelerates the converged electron beam, and the electric field formed between the Wehnelt and the anode is made asymmetric by making the shape of the anode asymmetric.

[0004] For example, the atmospheric gas in the vacuum chamber may be ionized by an electron beam to generate positive ions. When the electric field formed between the Wehnelt and the anode is symmetric, the positive ions are converged by the electric field and collide with the filament. When the positive ions collide with the filament, the filament may be damaged and the filament may be disconnected in some cases. On the other hand, by making the electric field formed between the Wehnelt and the anode asymmetric, the possibility of the positive ions colliding with the filament can be reduced.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if the electric field formed between the Wehnert and the anode is asymmetrical, the focusing ability of the electron beam emitted from the electron gun deteriorates. [Means for solving the problem]

[0007] One embodiment of the electron gun according to the present invention is: Filament and, A Wehnert device that focuses the electron beam emitted from the aforementioned filament, an anode that accelerates the electron beam emitted from the filament, Includes, The aforementioned Wehnert has a first part and a second part, The filament is positioned between the first portion and the second portion. The anode is located in the first direction of the first portion, In the first direction, the distance between the first portion and the anode is smaller than the distance between the second portion and the anode.

[0008] Such electron guns can reduce the deterioration of electron beam focusing that occurs when the electric field formed between the Wehnert and the anode is asymmetrical.

[0009] One aspect of the deposition apparatus according to the present invention is: This includes the electron gun mentioned above.

[0010] Such a deposition apparatus includes the electron gun described above, which reduces the deterioration of electron beam focusing that occurs when the electric field formed between the Wehnert and the anode is asymmetrical. [Brief explanation of the drawing]

[0011] [Figure 1] A diagram showing an example of the configuration of a vapor deposition apparatus related to one embodiment of the present invention. [Figure 2] A schematic plan view showing the electron source of an electron gun. [Figure 3] A schematic cross-sectional view showing the electron source of an electron gun. [Figure 4] A diagram for explaining the operation of an electron gun. [Figure 5] A diagram for explaining the operation of an electron gun. [Figure 6] A diagram for explaining the operation of an electron gun according to a comparative example. [Figure 7] A cross-sectional view schematically showing an electron beam emitted from an electron gun. [Figure 8] A cross-sectional view schematically showing an electron beam emitted from an electron gun according to a comparative example. [Figure 9] A graph showing the relationship between filament current and emission current. [Figure 10] A plan view schematically showing an electron generation source of an electron gun according to a first modification. [Figure 11] A cross-sectional view schematically showing an electron generation source of an electron gun according to a second modification. [Figure 12] A cross-sectional view schematically showing an electron generation source of an electron gun according to a third modification. [Figure 13] A cross-sectional view schematically showing an electron generation source of an electron gun according to a fourth modification.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0013] 1. Evaporation apparatus First, an evaporation apparatus according to an embodiment of the present invention will be described while referring to the drawings. FIG. 1 is a diagram showing an example of the configuration of an evaporation apparatus 100 according to the present embodiment.

[0014] The deposition apparatus 100 is a device for forming thin films on semiconductor substrates, lenses, etc., by electron beam deposition. Electron beam deposition is a method of forming thin films by irradiating a deposition material 102 with an electron beam EB emitted from an electron gun 110 in a vacuum, heating and evaporating the deposition material 102, and depositing the deposition material 102 onto a semiconductor substrate or the like. As shown in Figure 1, the deposition apparatus 100 includes an electron gun 110 and a water-cooled crucible 120. Although not shown, the electron gun 110 and the water-cooled crucible 120 are housed in a vacuum chamber that can be maintained in a vacuum state.

[0015] The electron gun 110 emits an electron beam EB. The electron beam EB emitted from the electron gun 110 is irradiated onto the deposition material 102 contained in a water-cooled crucible 120. The electron gun 110 includes an electron source 112, a magnetic field source 114, and a scanning coil 116.

[0016] The electron source 112 generates an electron beam EB. Details of the electron source 112 will be described later.

[0017] The magnetic field generator 114 generates a magnetic field to deflect the electron beam EB generated by the electron generator 112. The magnetic field generator 114 includes, for example, a magnet and a yoke magnetically connected to the magnet. The magnet may be a permanent magnet or an electromagnet. By connecting the yoke to the magnet, the leakage magnetic field from the magnet can be reduced, and a desired magnetic field can be generated.

[0018] The magnetic field source 114 deflects the electron beam EB in a range of 180 to 270 degrees, for example. A magnetic field is generated. In the example shown in Figure 1, the electron beam EB is deflected by 270 degrees by the magnetic field generated by the magnetic field source 114. The magnetic field generated by the magnetic field source 114 allows the electron beam EB generated by the electron source 112 to be irradiated onto the deposition material 102 contained in the water-cooled crucible 120.

[0019] The scanning coil 116 is a coil used to scan the deposited material 102 with the electron beam EB. The scanning coil 116 can deflect the electron beam EB in two dimensions. By deflecting the electron beam EB with the scanning coil 116, the electron beam EB can be scanned on the surface of the deposited material 102.

[0020] The water-cooled crucible 120 contains the deposition material 102. The water-cooled crucible 120 is equipped with a water cooling mechanism for cooling the deposition material 102, although it is not shown in the diagram. The electron beam EB emitted from the electron gun 110 irradiates the deposition material 102 contained in the water-cooled crucible 120, thereby heating and evaporating the deposition material 102. The evaporated deposition material 102 is deposited on a semiconductor substrate, lens, etc., placed in a vacuum chamber, although it is not shown in the diagram. This allows a thin film to be formed on the semiconductor substrate, etc. The deposition apparatus 100 can form, for example, optical films, oxide films, metal films, etc.

[0021] 2. Electron gun Figure 2 is a schematic plan view showing the electron source 112 of the electron gun 110. Figure 3 is a schematic cross-sectional view showing the electron source 112 of the electron gun 110. Note that Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figures 2 and 3 show three mutually orthogonal axes: the X-axis, Y-axis, and Z-axis.

[0022] The electron source 112 includes a filament 10, a Wehnert 20, and an anode 30, as shown in Figures 2 and 3.

[0023] The filament 10 generates an electron beam EB. By passing an electric current through the filament 10, the filament 10 is heated. As a result, thermionic electrons are emitted from the filament 10. A negative high voltage is applied to the filament 10. The material of the filament 10 is, for example, tungsten. The filament 10 has a cylindrical shape with a wire wound in a spiral. In the filament 10, the number of turns of the wire and the wire diameter are not particularly limited. The central axis of the filament 10 is parallel to the X axis. The filament 10 is positioned in the opening 22 of the Wehnelt 20.

[0024] The Wehnert 20 focuses the electron beam EB emitted from the filament 10. A negative high voltage is applied to the Wehnert 20. The filament 10 and the Wehnert 20 constitute the cathode.

[0025] The Wehnert 20 has a first portion 24a, a second portion 24b, a third portion 24c, and a fourth portion 24d. Each of the first portion 24a, the second portion 24b, the third portion 24c, and the fourth portion 24d has, for example, a plate-like shape.

[0026] The first part 24a is located in the +Y direction of the filament 10. Here, the electron beam EB emitted from the filament 10 is deflected in the +Y direction by the magnetic field generated by the magnetic field source 114. The first part 24a is located in the +Y direction of the filament 10, that is, in the direction (+Y direction) in which the electron beam EB is deflected by the magnetic field generated by the magnetic field source 114 of the filament 10.

[0027] The second part 24b is located in the -Y direction of the filament 10. That is, the second part 24b is located in the opposite direction (-Y direction) to the direction (+Y direction) in which the electron beam EB is deflected by the magnetic field generated by the magnetic field source 114 of the filament 10. The filament 10 is positioned between the first part 24a and the second part 24b.

[0028] The third part 24c is located in the +X direction of the filament 10. The fourth part 24d is located in the -X direction of the filament 10. The third part 24c and the fourth part 24d are separated. The third part 24c connects the +X end of the first part 24a to the +X end of the second part 24b. The fourth part 24d connects the -X end of the first part 24a to the -X end of the second part 24b. The filament 10 is positioned between the third part 24c and the fourth part 24d.

[0029] As shown in Figure 2, the filament 10 is enclosed by a first portion 24a, a second portion 24b, a third portion 24c, and a fourth portion 24d when viewed from a direction along the Z-axis, i.e., in a plan view. The space enclosed by the first portion 24a, the second portion 24b, the third portion 24c, and the fourth portion 24d constitutes the opening 22. In a plan view, the shape of the opening 22 is, for example, a rectangle. The filament 10 is not in contact with any of the first portion 24a, the second portion 24b, the third portion 24c, and the fourth portion 24d.

[0030] As shown in Figure 3, the first part 24a protrudes more in the +Z direction than the second part 24b. That is, in the +Z direction (along the Z axis), the distance D1 between the first part 24a and the anode 30 is smaller than the distance D2 between the second part 24b and the anode 30. Here, the distance D1 between the first part 24a and the anode 30 is the shortest distance between the first part 24a and the anode 30 in the direction along the Z axis. The same applies to distance D2, which is the shortest distance between the second part 24b and the anode 30 in the direction along the Z axis. Distance D1 is set to a distance that does not cause dielectric breakdown between the Wehnelt 20 and the anode 30.

[0031] The first part 24a has an upper surface 2a facing the +Z direction, and the anode 30 has a lower surface 3d facing the -Z direction. That is, the upper surface 2a of the first part 24a and the lower surface 3d of the anode 30 face each other. Here, the distance D1 between the first part 24a and the anode 30 is the distance between the upper surface 2a of the first part 24a and the lower surface 3d of the anode 30.

[0032] Furthermore, the second portion 24b has an upper surface 4a facing the +Z direction. The distance D2 between the second portion 24b and the anode 30 is the distance between the upper surface 4a of the second portion 24b and the lower surface 3d of the anode 30 in the +Z direction.

[0033] Similarly, the third portion 24c protrudes more in the +Z direction than the second portion 24b. That is, in the +Z direction, the distance between the third portion 24c and the anode 30 is smaller than the distance D2 between the second portion 24b and the anode 30. The distance between the third portion 24c and the anode 30 is equal to, for example, the distance D1. The upper surface 2a of the first portion 24a facing the +Z direction and the upper surface of the third portion 24c facing the +Z direction are, for example, flush.

[0034] Similarly, the fourth portion 24d protrudes more in the +Z direction than the second portion 24b. That is, in the +Z direction, the distance between the fourth portion 24d and the anode 30 is smaller than the distance D2 between the second portion 24b and the anode 30. The distance between the fourth portion 24d and the anode 30 is equal to, for example, the distance D1. The upper surface 2a of the first portion 24a facing the +Z direction and the upper surface of the fourth portion 24d facing the +Z direction are, for example, flush.

[0035] In the +Z direction, the distance D10 between the filament 10 and the anode 30 is greater than the distance D1 between the first part 24a and the anode 30. Also, in the +Z direction, The distance D10 between the filament 10 and the anode 30 is smaller than the distance D2 between the second part 24b and the anode 30. Here, distance D10 is the shortest distance between the filament 10 and the anode 30 in the +Z direction, and is the distance between the end of the filament 10 in the +Z direction and the lower surface 3d of the anode 30.

[0036] The corner 2 of the first part 24a on the filament 10 side is chamfered. That is, the corner 2 of the first part 24a in the -Y direction is chamfered. The first part 24a has an upper surface 2a facing the +Z direction, a side surface 2b facing the -Y direction, and an inclined surface 2c connecting the upper surface 2a and the side surface 2b. The side surface 2b faces the opening 22. The inclination angle θ2 of the inclined surface 2c with respect to the upper surface 2a is acute. The inclination angle θ2 of the inclined surface 2c with respect to the upper surface 2a is, for example, 45 degrees. The inclined surface 2c constitutes the chamfered corner 2.

[0037] The corner 6 on the filament 10 side of the third portion 24c is chamfered. That is, the corner 6 in the -X direction of the third portion 24c is chamfered. The third portion 24c has an inclined surface 6c with the same inclination angle as the inclined surface 2c. Note that the inclination angle of the inclined surface 6c may be different from the inclination angle θ2 of the inclined surface 2c. The inclined surface 6c constitutes the chamfered corner 6.

[0038] Similarly, the corner 8 on the filament 10 side of the fourth portion 24d is chamfered. That is, the corner 8 in the +X direction of the fourth portion 24d is chamfered. The fourth portion 24d has an inclined surface 8c with the same inclination angle as the inclined surface 2c. Note that the inclination angle of the inclined surface 8c may be different from the inclination angle θ2 of the inclined surface 2c. The inclined surface 8c constitutes the chamfered corner 8.

[0039] Note that the corner of the second part 24b on the filament 10 side is not chamfered. The corner of the second part 24b on the filament 10 side is connected, for example, to the upper surface 4a of the second part 24b facing the +Z direction and the side of the second part 24b facing the +Y direction.

[0040] The anode 30 accelerates the electron beam EB emitted from the filament 10. The anode 30 is connected to the ground potential (reference potential, e.g., 0V). Alternatively, a positive potential may be applied to the anode 30. By applying the ground potential or a positive potential to the anode 30, an electric field can be formed between the Wehnelt 20 and the anode 30 to accelerate the electron beam EB emitted from the filament 10.

[0041] Anode 30 is located in the +Z direction of the first part 24a. Anode 30 faces the first part 24a. Specifically, the lower surface 3d of anode 30 faces the upper surface 2a of the first part 24a. In plan view, anode 30 and the first part 24a overlap.

[0042] The anode 30 is not located in the +Z direction of the second portion 24b. The upper surface 4a of the second portion 24b facing the +Z direction is open.

[0043] Anode 30 is located in the +Z direction of the third part 24c. Anode 30 is opposite to the third part 24c. In a plan view, anode 30 and the third part 24c overlap. Also, anode 30 is located in the +Z direction of the fourth part 24d. Anode 30 is opposite to the fourth part 24d. In a plan view, anode 30 and the fourth part 24d overlap.

[0044] The anode 30 has a first electrode portion 32a, a second electrode portion 32b, and a third electrode portion 32c. Each of the first electrode portion 32a, the second electrode portion 32b, and the third electrode portion 32c is For example, it has a plate-like shape.

[0045] In a plan view, the first electrode portion 32a is located in the +Y direction of the filament 10. In a plan view, the second electrode portion 32b is located in the +X direction of the filament 10. In a plan view, the third electrode portion 32c is located in the -X direction of the filament 10. The second electrode portion 32b is connected to the +X end of the first electrode portion 32a, and the third electrode portion 32c is connected to the -X end of the first electrode portion 32a. In a plan view, the filament 10 is located between the second electrode portion 32b and the third electrode portion 32c.

[0046] The first electrode portion 32a is located in the +Z direction of the first portion 24a of the Wehnelt 20. The second electrode portion 32b is located in the +Z direction of the third portion 24c of the Wehnelt 20. The third electrode portion 32c is located in the +Z direction of the fourth portion 24d of the Wehnelt 20.

[0047] Thus, in a plan view, the anode 30 is asymmetric with respect to axis A, which is parallel to the X-axis. Axis A coincides, for example, with the central axis of the filament 10. In contrast, the Wehnelt 20 is symmetric with respect to axis A in a plan view. Therefore, the electric field formed between the Wehnelt 20 and the anode 30 is asymmetric with respect to axis A. That is, the potential distribution formed between the Wehnelt 20 and the anode 30 is asymmetric with respect to axis A.

[0048] The corner 3 on the filament 10 side of the anode 30 is chamfered. In the example shown in Figure 3, the corner 3 on the filament 10 side of the first electrode portion 32a of the anode 30, i.e., the corner 3 in the -Y direction of the first electrode portion 32a, is chamfered. Furthermore, the corner 5 on the filament 10 side of the second electrode portion 32b of the anode 30, i.e., the corner 5 in the -X direction of the second electrode portion 32b, is chamfered. Furthermore, the corner 7 on the filament 10 side of the third electrode portion 32c of the anode 30, i.e., the corner 7 in the +X direction of the third electrode portion 32c, is chamfered.

[0049] The corner 3 of the first electrode portion 32a in the -Y direction is chamfered. As shown in Figure 3, the first electrode portion 32a has an upper surface 3a facing the +Z direction, a side surface 3b facing the -Y direction, and an inclined surface 3c connecting the upper surface 3a and the side surface 3b. The side surface 3b is connected to the lower surface 3d. The inclination angle θ3 of the inclined surface 3c with respect to the upper surface 3a is acute. For example, the inclination angle θ3 of the inclined surface 3c with respect to the upper surface 3a is 40 degrees. The inclined surface 3c constitutes the chamfered corner 3.

[0050] The corner 5 in the -X direction of the second electrode portion 32b of the anode 30 is chamfered. The second electrode portion 32b has an inclined surface 5c with the same inclination angle as the inclined surface 3c. Note that the inclination angle of the inclined surface 5c may be different from the inclination angle θ3 of the inclined surface 3c. The inclined surface 5c constitutes the chamfered corner 5.

[0051] The corner 7 in the +X direction of the third electrode portion 32c of the anode 30 is chamfered. The third electrode portion 32c has an inclined surface 7c with the same inclination angle as the inclined surface 3c. Note that the inclination angle of the inclined surface 7c may be different from the inclination angle θ3 of the inclined surface 3c. The inclined surface 7c constitutes the chamfered corner 7.

[0052] 3. Operation of the electron gun Figure 4 is a diagram illustrating the operation of the electron gun 110.

[0053] An electric current is passed through the filament 10, heating it and causing it to emit thermionic electrons. A negative high voltage is applied to the filament 10 and the Wehnelt 20, and the anode 30 is grounded and maintained at ground potential. This creates a current between the Wehnelt 20 and the anode 30 that accelerates thermionic electrons and forms an electron beam EB. An electric field is formed. Thermionic electrons emitted from the filament 10 are accelerated by the electric field formed between the Wehnert 20 and the filament 10, forming an electron beam EB.

[0054] A positive potential may be applied to the anode 30. Even when a positive potential is applied to the anode 30, the electron gun 110 operates in the same way as when a ground potential is applied to the anode 30.

[0055] In the electron gun 110, as described above, the anode 30 is asymmetric with respect to axis A in a plan view, so an asymmetric electric field is formed with respect to axis A. Specifically, a first electrode portion 32a is provided on the +Y direction side of axis A, but no electrode portion corresponding to the first electrode portion 32a is provided on the -Y direction side of axis A. By making the electric field formed between the Wehnelt 20 and the anode 30 asymmetric in this way, the positive ions IB pass on the -Y direction side of the trajectory of the electron beam EB. Therefore, the possibility of positive ions IB colliding with the second portion 24b of the Wehnelt 20 can be increased, and the possibility of positive ions IB colliding with the filament 10 can be reduced.

[0056] Positive ions (IB) are ions generated when the atmospheric gas in a vacuum chamber is ionized by an electron beam (EB). For example, when depositing oxides, oxygen is introduced as the atmospheric gas into the vacuum chamber. Oxygen is ionized by the electron beam (EB), generating positive ions (IB). In some cases, an inert gas such as argon may be introduced as the atmospheric gas into the vacuum chamber, and this inert gas is ionized by the electron beam (EB), generating positive ions (IB).

[0057] For example, if the electric field formed between the Wehnelt 20 and the anode 30 is symmetric with respect to axis A, the positive ions IB will be focused by the electric field and collide with the filament 10. This collision of positive ions IB with the filament 10 can damage the filament 10, potentially causing it to break. In contrast, if the electric field formed between the Wehnelt 20 and the anode 30 is asymmetric, the likelihood of positive ions IB colliding with the filament 10 can be reduced, thereby reducing the likelihood of the filament 10 being damaged.

[0058] Figure 5 is a diagram illustrating the operation of the electron gun 110, and Figure 6 is a diagram illustrating the operation of the electron gun 110 according to the comparative example. Figure 7 is a schematic cross-sectional view showing the electron beam EB emitted from the electron gun 110, and Figure 8 is a schematic cross-sectional view showing the electron beam EB emitted from the electron gun 110 according to the comparative example. Note that in Figures 5 to 8, the influence of the magnetic field generated by the magnetic field source 114 is ignored.

[0059] In the electron gun 110, as shown in Figure 5, the distance D1 between the first part 24a of the Wehnert 20 and the anode 30 is smaller than the distance D2 between the second part 24b of the Wehnert 20 and the anode 30. Therefore, the divergence of the electron beam EB in the +Y direction can be reduced.

[0060] As shown in Figure 6, the anode 30 is located in the +Y direction of the filament 10, but not in the -Y direction. Therefore, as shown in Figure 6, when the distance D1 between the first part 24a and the anode 30 is equal to the distance D2 between the second part 24b and the anode 30, the equipotential lines are denser in the +Y direction of the filament 10 compared to the space in the -Y direction of the filament 10, and the potential changes more abruptly. Consequently, the electron beam EB emitted from the filament 10 diverges in the +Y direction. As a result, as shown in Figure 8, the cross-sectional shape of the electron beam EB emitted from the electron gun 110 is elliptical with a major axis along the Y axis.

[0061] In contrast, as shown in Figure 5, if distance D1 is made smaller than distance D2, then Figure 6 shows... Compared to the case where the indicated distance D1 is equal to the distance D2, the spacing between equipotential lines in the +Y direction space of the filament 10 can be widened, reducing abrupt changes in potential. Therefore, the divergence of the electron beam EB emitted from the filament 10 in the +Y direction can be reduced. As a result, as shown in Figure 7, the cross-sectional shape of the electron beam EB emitted from the electron gun 110 can be made closer to a circle.

[0062] Therefore, as shown in Figure 5, by making the distance D1 smaller than the distance D2, the deterioration of electron beam EB focusing that occurs when the electric field formed between the Wehnert 20 and the anode 30 is made asymmetrical can be reduced.

[0063] Furthermore, in the electron gun 110, the corner 2 on the filament 10 side of the first portion 24a is chamfered. By chamfering the corner 2, the focusing ability of the electron beam EB can be improved. As shown in Figure 5, by chamfering the corner 2, the steep potential change near the corner 2 can be reduced compared to when the corner 2 is not chamfered, as shown in Figure 6. Therefore, when the corner 2 is chamfered as shown in Figure 5, the focusing ability of the electron beam EB in the direction along the Y axis can be improved compared to when the corner 2 is not chamfered as shown in Figure 6.

[0064] Furthermore, in the electron gun 110, as shown in Figure 2, the corner 6 on the filament 10 side of the third portion 24c of the Wehnert 20 and the corner 8 on the filament 10 side of the fourth portion 24d of the Wehnert 20 are chamfered. This improves the focusing ability of the electron beam EB in the direction along the X axis.

[0065] Furthermore, in the electron gun 110, the corner 3 on the filament 10 side of the first electrode portion 32a of the anode 30 is chamfered. By chamfering the corner 3, the possibility of the electron beam EB deflected in the +Y direction interfering with the anode 30 can be reduced. In addition, by chamfering the corner 3, the electron beam EB is less likely to be attracted to the anode 30 compared to when the corner 3 is not chamfered. Therefore, the focusing ability of the electron beam EB in the direction along the Y axis can be improved.

[0066] Furthermore, in the electron gun 110, the corner 5 on the filament 10 side of the second electrode portion 32b of the anode 30 and the corner 7 on the filament 10 side of the third electrode portion 32c of the anode 30 are chamfered. This reduces the possibility of the electron beam EB interfering with the anode 30 and improves the focusing ability of the electron beam EB in the direction along the X axis.

[0067] In the electron gun 110, the distance D10 between the filament 10 and the anode 30 is greater than the distance D1 between the first portion 24a and the anode 30. Therefore, the convergence of the electron beam EB emitted from the filament 10 can be enhanced. Further, in the +Z direction, the distance D10 between the filament 10 and the anode 30 is smaller than the distance D2 between the second portion 24b and the anode 30. Thus, by bringing the filament 10 closer to the anode 30 than the second portion 24b, the electron beam EB can be efficiently extracted from the filament 10, and the current amount of the electron beam EB emitted from the filament 10 can be increased. Therefore, in the electron gun 110, a large emission current (electron current emitted from the electron gun) can be obtained.

[0068] FIG. 9 is a graph showing the relationship between the filament current and the emission current when the distance D10 shown in FIG. 5 is greater than the distance D1 and the distance D10 is smaller than the distance D2 (D1 < D10 < D2). Here, the filament current is the current flowing through the filament 10.

[0069] In addition, in FIG. 9, as a comparative example, a graph showing the relationship between the filament current and the emission current when the distance D10 shown in FIG. 6 is greater than the distance D1 and the distance D10 is greater than the distance D2 (D1 = D2 < D10) is also shown. The case satisfying D1 < D10 < D2 is shown by a solid line, and the case satisfying D1 = D2 < D10 is shown by a broken line.

[0070] As shown in FIG. 9, when D1 < D10 < D2 is satisfied, a large emission current can be obtained with a small filament current as compared with the case when D1 = D2 < D10 is satisfied.

[0071] 4. Effects The electron gun 110 includes a filament 10, a Wehnert 20 for focusing the electron beam EB emitted from the filament 10, and an anode 30 for accelerating the electron beam EB emitted from the filament 10. The Wehnert 20 has a first portion 24a and a second portion 24b, the filament 10 is positioned between the first portion 24a and the second portion 24b, and the anode 30 is located in the +Z direction (an example of the first direction) of the first portion 24a. In the +Z direction, the distance D1 between the first portion 24a and the anode 30 is smaller than the distance D2 between the second portion 24b and the anode 30. Therefore, as described above, the electron gun 110 can reduce the deterioration of electron beam EB focusing that occurs when the electric field formed between the Wehnert 20 and the anode 30 is asymmetrical.

[0072] In the electron gun 110, the anode 30 is not located in the +Z direction of the second portion 24b. Therefore, in the electron gun 110, the electric field formed between the Wehnelt 20 and the anode 30 can be made asymmetrical. Consequently, in the electron gun 110, the probability of positive ions IB colliding with the second portion 24b can be increased, while the probability of positive ions IB colliding with the filament 10 can be reduced.

[0073] In the electron gun 110, the distance D10 between the filament 10 and the anode 30 in the +Z direction is greater than the distance D1 between the first part 24a and the anode 30. Therefore, the electron gun 110 can improve the focusing of the electron beam EB emitted from the filament 10. Furthermore, in the electron gun 110, the distance D10 between the filament 10 and the anode 30 in the +Z direction is smaller than the distance D2 between the second part 24b and the anode 30. Therefore, the electron gun 110 can efficiently extract the electron beam EB from the filament 10 and obtain a large emission current.

[0074] In the electron gun 110, the corner 3 on the filament 10 side of the first part 24a is chamfered. Therefore, the electron gun 110 can improve the focusing ability of the electron beam EB.

[0075] In the electron gun 110, the corner 3 on the filament 10 side of the anode 30 is chamfered. Therefore, the electron gun 110 can reduce the possibility of the electron beam EB, which is deflected in the +Y direction, interfering with the anode 30. This reduces the possibility of the anode 30 being damaged by the electron beam EB irradiating it.

[0076] In the electron gun 110, the Wehnert 20 has a third portion 24c connecting the first portion 24a and the second portion 24b, and a fourth portion 24d that is separated from the third portion 24c and connects the first portion 24a and the second portion 24b, and the filament 10 is positioned between the third portion 24c and the fourth portion 24d. Therefore, in the electron gun 110, the filament 10 can be positioned in the region enclosed by the first portion 24a, the second portion 24b, the third portion 24c, and the fourth portion 24d.

[0077] In the electron gun 110, the corner 6 on the filament 10 side of the third part 24c is chamfered, and the corner 8 on the filament 10 side of the fourth part 24d is chamfered. Therefore, The subgun 110 can improve the focusing of the electron beam EB in the direction along the X-axis.

[0078] The electron gun 110 includes a magnetic field source 114 that generates a magnetic field to deflect the electron beam EB accelerated by the anode 30 in the +Y direction (an example of a second direction), and the first part 24a is located in the +Y direction of the filament 10. Therefore, the electron gun 110 can reduce the possibility of positive ions IB colliding with the filament 10. Furthermore, the electron gun 110 can improve the focusing ability of the electron beam EB.

[0079] The deposition apparatus 100 includes an electron gun 110. Therefore, the deposition apparatus 100 can reduce the deterioration of electron beam EB focusing that occurs when the electric field formed between the Wehnelt 20 and the anode 30 is asymmetrical. Consequently, the deposition apparatus 100 can irradiate the deposition material 102 with a focused electron beam EB.

[0080] 5. Variations 5.1. First Variation Figure 10 is a schematic plan view showing the electron source 112 of the electron gun 110 according to the first modified example.

[0081] In the electron gun 110 shown in Figure 2 above, the third portion 24c and the fourth portion 24d of the Wehnert 20 protruded in the +Z direction. That is, the distance between the third portion 24c and the anode 30 was smaller than the distance D2 between the second portion 24b and the anode 30, and the distance between the fourth portion 24d and the anode 30 was smaller than the distance D2 between the second portion 24b and the anode 30.

[0082] In contrast, as shown in Figure 10, the third portion 24c and the fourth portion 24d of the Wehnert 20 do not have to protrude in the +Z direction. That is, the distance between the third portion 24c and the anode 30 may be equal to the distance D2 between the second portion 24b and the anode 30, and the distance between the fourth portion 24d and the anode 30 may be equal to the distance D2 between the second portion 24b and the anode 30. The upper surface 4a of the second portion 24b, the upper surface of the third portion 24c, and the upper surface of the fourth portion 24d may be flush with the surface.

[0083] Furthermore, in the electron gun 110 shown in Figure 2 above, the corners 6 of the third portion 24c and the corners 8 of the fourth portion 24d of the Wehnert 20 were chamfered. In contrast, as shown in Figure 10, the corners 6 of the third portion 24c and the corners 8 of the fourth portion 24d of the Wehnert 20 do not need to be chamfered.

[0084] 5.2. Second Variation Figure 11 is a schematic cross-sectional view showing the electron source 112 of the electron gun 110 according to the second modified example.

[0085] In the electron gun 110 shown in Figure 3 above, the corner 3 on the filament 10 side of the anode 30 was chamfered. In contrast, as shown in Figure 11, the corner 3 on the filament 10 side of the anode 30 does not need to be chamfered. The corner 3 has an upper surface 3a facing the +Z direction and a side surface 3b facing the -Y direction connected.

[0086] 5.3. Third Variation The second part 24b of the Wehnelt 20 may be interchangeable. For example, the second part 24b may be detachable from the first part 24a, the third part 24c, and the fourth part 24d. The interchangeability of the second part 24b allows positive ions IB to collide. If the second part 24b is destroyed by this process, the second part 24b can be replaced. It is also possible that only a portion of the second part 24b is replaceable.

[0087] Figure 12 is a schematic cross-sectional view showing an electron gun 110 according to a third modified example. The electron gun 110 may include a cover 25 that covers the second portion 24b, as shown in Figure 12. The cover 25 is detachable from the second portion 24b. Therefore, in the electron gun 110, the positive ions IB do not collide with the second portion 24b, but rather with the cover 25, thus reducing damage to the second portion 24b caused by irradiation with positive ions IB. It is desirable that the cover 25 be made of a non-magnetic material that is resistant to sputtering.

[0088] 5.4. Fourth Variation Figure 13 is a schematic cross-sectional view showing an electron gun 110 according to the fourth modified example. In the example shown in Figure 3 described above, the magnetic field source 114 generates a magnetic field that deflects the electron beam EB in the +Y direction, and the first part 24a of the Wehnert 20 was located in the +Y direction of the filament 10. That is, the first part 24a was located in the direction (+Y direction) in which the electron beam EB is deflected by the magnetic field generated by the magnetic field source 114 of the filament 10.

[0089] In contrast, as shown in Figure 13, when the magnetic field source 114 generates a magnetic field that deflects the electron beam EB in the +Y direction, the first portion 24a of the Wehnert 20 may be located in the -Y direction of the filament 10. That is, the first portion 24a may be located in the opposite direction (-Y direction) to the direction (+Y direction) in which the electron beam EB is deflected by the magnetic field of the filament 10. In this case, the first electrode portion 32a of the anode 30 may also be located in the -Y direction of the filament 10. The electron gun 110 shown in Figure 13 can also improve the focusing ability of the electron beam EB, similar to the electron gun 110 shown in Figure 3.

[0090] The embodiments and modifications described above are merely examples and are not limiting. For example, each embodiment and each modification can be combined as appropriate.

[0091] The present invention is not limited to the embodiments described above, and various further modifications are possible. For example, the present invention includes configurations that are substantially identical to those described in the embodiments. A substantially identical configuration is, for example, a configuration that has the same function, method, and result, or a configuration that has the same purpose and effect. The present invention also includes configurations in which non-essential parts of the configuration described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as the configuration described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configuration described in the embodiments. [Explanation of Symbols]

[0092] 2…corner, 2a…top, 2b…side, 2c…sloping surface, 3…corner, 3a…top, 3b…side, 3c…sloping surface, 3d…bottom, 4a…top, 5…corner, 5c…sloping surface, 6…corner, 6c…sloping surface, 7…corner, 7c…sloping surface, 8…corner, 8c…sloping surface, 10…frament, 20…winglet, 22…opening, 24a…Part 1, 24b…Part 2, 24c…Part 3, 24d…Part 4, 25…Cover, 30…Anod, 32a…Electrode 1, 32b…Electrode 2, 32c…Electrode 3, 100…Electrode device, 102…Electrode material, 110…Electro-gun, 112…Electro-generating source, 114…Magnetic-generating source, 116…Tracking collage

Claims

1. Filament and, A Wehnert device that focuses the electron beam emitted from the aforementioned filament, an anode that accelerates the electron beam emitted from the filament, Includes, The aforementioned Wehnert has a first part and a second part, The filament is positioned between the first portion and the second portion. The anode is located in the first direction of the first portion, An electron gun in which, in the first direction, the distance between the first portion and the anode is smaller than the distance between the second portion and the anode.

2. In claim 1, The electron gun wherein the anode is not located in the first direction of the second portion.

3. In claim 1, An electron gun in which, in the first direction, the distance between the filament and the anode is greater than the distance between the first portion and the anode.

4. In claim 3, An electron gun in which, in the first direction, the distance between the filament and the anode is smaller than the distance between the second portion and the anode.

5. In claim 1, The corner of the first portion on the filament side is chamfered, in the electron gun.

6. In claim 1, The corner of the anode on the filament side is chamfered, in this electron gun.

7. In claim 1, The second part is a replaceable electron gun.

8. In claim 1, The aforementioned Wehnert said, A third part connecting the first part and the second part, A fourth part that is separated from the third part and connects the first part and the second part, It has, The filament is an electron gun positioned between the third and fourth parts.

9. In claim 8, The corner of the third portion on the filament side is chamfered. The corner of the fourth portion on the filament side is chamfered, in the electron gun.

10. In claim 1, The system includes a magnetic force source that generates a magnetic field for deflecting the electron beam accelerated by the anode in a second direction, The first part is an electron gun located in the second direction of the filament.

11. A vapor deposition apparatus comprising an electron gun according to any one of claims 1 to 10.

Images