Electron gun for evaporation

Abstract

To provide an electron gun device for vapor deposition that suppresses deterioration of film formation quality. [Solution] The electron gun device for vapor deposition disclosed herein comprises an apparatus main body equipped with an electron beam source and installed to the side of a crucible that is open at the top and contains an evaporation material to be vapor-deposited on a coating member, and a pair of pole pieces that guide the electron beam emitted from the apparatus main body to a target area set in the crucible, wherein the pair of pole pieces include a base end installed on the apparatus main body, a tip end disposed above the crucible and behind the target area as seen from the apparatus main body, a first connecting portion extending from the base end toward the tip end, and a second connecting portion connecting the end of the first connecting portion to the tip end and extending in a second direction that intersects with a first direction along a straight line connecting the apparatus main body and the target area, wherein the length of the second connecting portion in the first direction is longer than the length of the tip end in the first direction.

Description

[Technical Field]

[0001] The present disclosure relates to an electron gun apparatus for vapor deposition. [Background technology]

[0002] A vacuum deposition apparatus is known that forms a film of a coating material by heating and evaporating an evaporation material placed in a vacuum chamber, and then attaching the resulting evaporated particles to the coating material, such as a component that constitutes an optical device, such as a substrate or a lens (see, for example, Patent Document 1 below).

[0003] The following Patent Document 1 describes an electron gun device included in a vacuum deposition device, in which an electron beam generated from an electron beam generating means is deflected by a deflection magnetic field generating means including a pole piece and made to impinge on an evaporation material in a crucible. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-007269 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned vacuum deposition apparatuses are often used for thin film formation in the field of optical devices. With the recent trend toward higher performance of optical devices, there is a demand for suppressing optical loss (e.g., scattering and absorption) in optical thin films formed on optical devices. In response to this demand, there is a demand for improved thin film deposition accuracy in vacuum deposition apparatuses. However, existing vacuum deposition apparatuses, particularly deposition electron gun apparatuses used in vacuum deposition apparatuses, still have room for improvement in terms of suppressing deterioration in the film deposition quality of coated members.

[0006] In consideration of the above, an object of the present disclosure is to provide an evaporation electron gun apparatus that suppresses deterioration in film formation quality. [Means for solving the problem]

[0007] In order to achieve the above object, an evaporation electron gun device according to a first aspect of the present disclosure includes: an apparatus main body having an electron beam source and installed to the side of a crucible that is open at the top and contains an evaporation material to be evaporated onto a coating member; and a pair of pole pieces that guide the electron beam emitted from the apparatus main body to a target area set in the crucible, wherein the pair of pole pieces include a base end installed on the apparatus main body, a tip end disposed above the crucible and behind the target area as seen from the apparatus main body, a first connecting portion extending from the base end toward the tip end, and a second connecting portion connecting an end of the first connecting portion to the tip end and extending in a second direction intersecting a first direction along a straight line connecting the apparatus main body and the target area, wherein the length of the second connecting portion in the first direction is longer in a direction away from the apparatus main body than the length of the tip end in the first direction.

[0008] In this type of electron gun for deposition, a part of the second connecting part generates a magnetic field behind the tip part, and this magnetic field can deflect the reflected electrons that are reflected and emitted onto the target area. This effectively reduces the energy of the reflected electrons, which are part of the electron beam, making it difficult for the reflected electrons to reach the coating material, thereby preventing a decrease in the quality of the coating material.

[0009] An electron gun device for deposition according to a second aspect of the present disclosure is the electron gun device for deposition according to the first aspect of the present disclosure, wherein the thickness of at least a portion of the first connecting portion along a third direction intersecting the first direction and the second direction is thicker than the thickness of the tip portion along the third direction.

[0010] In such an electron gun device for deposition, by increasing the thickness of the first connecting portion, the magnetic field generated around the first connecting portion can be made larger, and this magnetic field can deflect even reflected electrons that have reached the periphery of the first connecting portion.

[0011] An electron gun device for deposition according to a third aspect of the present disclosure is the electron gun device for deposition according to the first or second aspect of the present disclosure, wherein the pair of pole pieces further includes one or more magnetic field adjustment pieces extending in a direction away from the target region from the portion where the second connecting portion and the end of the first connecting portion are connected.

[0012] In such an electron gun device for deposition, a magnetic field can also be generated around the base of the second connecting part, which is relatively far from the target area, and this magnetic field can also deflect reflected electrons toward the base of the second connecting part.

[0013] According to a fourth aspect of the present disclosure, there is provided an electron gun device for vapor deposition, comprising: an apparatus main body having an electron beam source and installed to the side of a crucible having an open top and containing an evaporation material to be vapor-deposited on a coating member; and a pair of pole pieces for guiding the electron beam emitted from the apparatus main body to a target region set in the crucible, wherein the pair of pole pieces include a base end installed in the apparatus main body, a tip end disposed above the crucible and behind the target region as seen from the apparatus main body, a first connecting portion extending from the base end toward the tip end, a second connecting portion connecting an end of the first connecting portion to the tip end and extending in a second direction intersecting a first direction along a straight line connecting the apparatus main body and the target region, and one or more magnetic field adjustment pieces extending in a direction away from the target region from a portion where the second connecting portion and the end of the first connecting portion are connected.

[0014] In such an electron gun device for deposition, a magnetic field can be generated around the base of the second connecting part, which is relatively far from the target area, and this magnetic field can deflect reflected electrons toward the base of the second connecting part.

[0015] An electron gun device for deposition according to a fifth aspect of the present disclosure is the electron gun device for deposition according to any one of the first to fourth aspects of the present disclosure, wherein the first connecting portion includes a detour portion extending in a direction away from the target region.

[0016] In such an electron gun for deposition, the pole piece can be easily routed to a position away from the target area, which prevents the evaporation material from adhering to the surface of the pole piece, thereby preventing a decrease in the quality of the film formed on the coating member that occurs in association with the re-evaporation of the evaporation material adhering to the pole piece. [Effects of the Invention]

[0017] According to the deposition electron gun device of the present disclosure, it is possible to suppress a decrease in the quality of film formation. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic perspective view showing an example of an evaporation electron gun device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view of the deposition electron gun device shown in FIG. [Figure 3] FIG. 2 is a side view of the deposition electron gun device shown in FIG. [Figure 4] FIG. 2 is a schematic perspective view showing a first modified example of the deposition electron gun device shown in FIG. [Figure 5] FIG. 2 is a schematic perspective view showing a second modified example of the deposition electron gun device shown in FIG. [Figure 6] FIG. 10 is a schematic perspective view showing an example of an evaporation electron gun device according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, each embodiment for carrying out the present disclosure will be described with reference to the drawings. Note that the scope necessary for the explanation to achieve the object of the present disclosure will be schematically shown below, and the scope necessary for explaining the relevant parts of the present disclosure will be mainly explained, and the parts for which explanation is omitted will be referred to as publicly known technologies. Furthermore, identical or similar reference numerals will be used for identical or corresponding components in the drawings, and duplicate explanations will be omitted. Furthermore, when a plurality of identical or corresponding components are included in the drawings, only some of them may be referenced to make the drawings easier to understand.

[0020] First Embodiment Fig. 1 is a schematic perspective view showing an example of an evaporation electron gun device according to a first embodiment of the present disclosure. Fig. 2 is a plan view of the evaporation electron gun device shown in Fig. 1. Fig. 3 is a side view of the evaporation electron gun device shown in Fig. 1. In the following description, the direction indicated by arrow A in Figs. 1 to 3 is provisionally defined as the left-right direction, the direction indicated by arrow B as the front-rear direction, and the direction indicated by arrow C as the height direction (or up-down direction).

[0021] The deposition electron gun device 1 according to this embodiment can be employed as part of a vacuum deposition device. This vacuum deposition device may include at least a vacuum chamber (not shown) capable of creating a substantially vacuum state inside, a substrate (not shown) as an example of a coating member supported at an arbitrary position within the vacuum chamber, for example, above, a crucible (sometimes called a "hearth" or "hearth liner") 3 containing an evaporation material 2 to be deposited on the substrate, and the deposition electron gun device 1. Note that the deposition electron gun device 1 of the present disclosure can also be applied to deposition devices other than the vacuum deposition device configured as described above.

[0022] 1 to 3, the evaporation electron gun device 1 according to this embodiment may be an apparatus that is disposed adjacent to a crucible 3 and that irradiates an evaporation material 2 contained in the crucible 3 with an electron beam EB. Note that the term "adjacent" as used here means that the device is adjacent to the crucible 3, and may be disposed to the side of the crucible 3 as shown in FIG. 1, or may include a device that is disposed at least partially below the crucible 3.

[0023] As shown in Fig. 2, the crucible 3 exemplified in this embodiment has a circular container 3A that is open at the top. The container 3A may contain an evaporation material 2 that is circular like the container 3A but slightly smaller than the container 3A. The crucible 3 may be connected to a rotation mechanism (not shown) and be rotatable in the horizontal direction in order to change the evaporation material 2 positioned in the target area TA. The rotation speed of the crucible 3 may be adjusted taking into account the capacity and evaporation speed of the evaporation material 2, etc.

[0024] In this embodiment, the crucible 3 is exemplified as having a circular container 3A, but the shape of the crucible 3 is not limited thereto. For example, a single cup-shaped crucible having an opening substantially the same size as the target area TA can be used. Alternatively, multiple cup-shaped crucibles can be arranged in a circle at predetermined intervals on a disk-shaped turntable, and the crucible irradiated with the electron beam can be changed by rotating the turntable. Furthermore, the opening of the container 3A of the crucible 3, excluding the target area TA, may be covered with a cover member (not shown) to prevent unintended heating and external contamination due to collisions with reflected electrons RE (described later).

[0025] Any material desired to be deposited on a substrate may be used as the evaporation material 2. Specific examples include silicon oxide (SiO2), titanium oxide (TiO2), and zirconium oxide (ZrO2). When the electron beam EB is irradiated onto the portion of the annular evaporation material 2 located in the target area TA, the evaporation material 2 in that portion is heated, melted, and evaporated, and is then deposited on the surface of a substrate placed above the target area TA.

[0026] The above-mentioned evaporation electron gun device 1 includes at least an apparatus main body 10, at least a portion of which is installed to the side of the crucible 3, and an electron beam deflection means 20 that guides the electron beam EB irradiated from the apparatus main body 10 to a target area TA set in the crucible 3.

[0027] The apparatus main body 10 is a member that is installed to the side of the crucible 3 and is capable of irradiating the electron beam EB. The apparatus main body 10 may include a housing 11, an electron beam source 12 provided inside the housing 11, and a window 13 formed in the upper part of the housing 11.

[0028] The electron beam source 12 may include, for example, a filament that emits thermoelectrons and an accelerator that accelerates the thermoelectrons to form an electron beam EB. The housing 11 may accommodate the electron beam source 12 therein, have a flat top surface, and have a window 13 formed as a through-hole in part of the top surface. A scan coil (not shown) may be disposed around the window 13 in the housing 11 to scan the electron beam EB within the target area TA. The electron beam EB generated by the electron beam source 12 including the above-described configuration is emitted outside the housing 11 through the window 13.

[0029] The electron beam deflection means 20 is a means for deflecting the electron beam EB generated in the apparatus main body 10 and emitted outside the housing 11, and guiding the electron beam EB to a target area TA set in the crucible 3. The electron beam deflection means 20 includes at least a pair of pole pieces 21L, 21R. The pair of pole pieces 21L, 21R are capable of guiding the electron beam EB to the target area TA by generating a magnetic field around them. The electron beam deflection means 20 may further include a magnetic source 22 for generating a magnetic field around the pair of pole pieces 21L, 21R.

[0030] The pair of pole pieces 21L, 21R may be configured as strip-shaped members made of a ferromagnetic material and having a predetermined thickness. The pair of pole pieces 21L, 21R may be arranged so as to sandwich a straight line L connecting the device body 10, more specifically, the window portion 13, and the target area TA of the crucible 3. More preferably, the pair of pole pieces 21L, 21R may be arranged with a gap between them so as to be symmetrical with respect to the straight line L. Note that the straight line L may substantially coincide with the horizontal traveling direction of the electron beam EB. Furthermore, in this embodiment, the pair of pole pieces 21L, 21R are symmetrical with respect to the straight line L, but the shapes of the pair of pole pieces 21L, 21R do not need to be symmetrical and may have different shapes.

[0031] The magnetic source 22 can be configured with a permanent magnet or an excitation coil (electromagnet). This magnetic source 22 can magnetize (excite) the pole pieces 21L, 21R, etc. by being connected to the pole pieces 21L, 21R or other members of the device body 10.

[0032] One of the factors that can reduce the quality of a film formed on a coated member in a vacuum deposition apparatus, including an existing electron gun for deposition, is thin-film contamination, which occurs when the evaporated material from the target region is deposited on a member other than the coated member. This type of thin-film contamination is particularly likely to occur when a pole piece is disposed above the target region. This is thought to occur because the evaporated material from the crucible adheres to and accumulates on the pole piece, then falls into or near the crucible and re-evaporates, or the deposited evaporated material is heated on the surface of the pole piece and re-evaporates. It is known that the re-evaporated material may be different from the evaporated material in the crucible, or the re-evaporated material itself may be altered or its evaporation rate may be uncontrollable, thereby affecting the quality of the film formed.

[0033] In addition, evaporation of the evaporation material can occur not only in the target area but also in areas surrounding the target area that are heated and reach high temperatures as the target area is heated (hereinafter referred to as "high-temperature areas"). Therefore, the deterioration of film formation quality due to the above-mentioned factors can be substantially avoided if pole pieces are not placed above the target area and high-temperature areas. However, in order to deflect the electron beam in a desired direction without placing pole pieces above the target area and high-temperature areas, it is necessary to accurately control the magnetic field around the electron beam, which is not easy.

[0034] In the pair of pole pieces 21L, 21R in this embodiment, in order to generate the most effective magnetic field for stably irradiating the electron beam EB onto the target area TA, the tip portions 32L, 32R are arranged in a position relatively close to the target area TA, more specifically, behind the target area TA as seen from the apparatus body 10. On the other hand, in consideration of the above-mentioned contamination, the portions of the pair of pole pieces 21L, 21R other than the tip portions 32L, 32R have a structure that is bent in a substantially L-shape in a plan view so as to pass through a position relatively distant from the target area TA and the high temperature area HA.

[0035] Explaining in more detail, the pair of pole pieces 21L, 21R includes at least base ends 31L, 31R installed in the device body 10, tip ends 32L, 32R arranged above the crucible 3 and behind the target area TA as viewed from the device body 10, and first connecting portions 33L, 33R and second connecting portions 34L, 34R connecting the base ends 31L, 31R and the tip ends 32L, 32R.

[0036] The base ends 31L and 31R may be located at positions sandwiching the window portion 13 on the housing 11. The base ends 31L and 31R may be connected to a magnetic source 22. Furthermore, it is preferable that the base ends 31L and 31R are located below the opening of the accommodation portion 3A of the crucible 3, since they are not substantially exposed to the evaporation material 2 evaporated from the crucible 3.

[0037] The tip portions 32L, 32R may be disposed so as to face each other with a predetermined gap between them in the front-to-rear direction of the target area TA. The shape of the tip portions 32L, 32R is preferably such that at least a portion of the facing end faces approach each other from the front to the rear in a plan view, as shown in Figures 1 and 2, so that the direction of the magnetic field formed around the tip portions 32L, 32R is directed toward the target area TA.

[0038] The first connecting portions 33L, 33R constitute at least a portion of the pair of pole pieces 21L, 21R extending from the base ends 31L, 31R in a direction approaching the tip ends 32L, 32R. The first connecting portions 33L, 33R may constitute a portion of the pair of pole pieces 21L, 21R extending generally along the front-rear direction from the apparatus body 10 toward the crucible 3. The first connecting portions 33L, 33R in this embodiment are constituted by detour portions 35L, 35R connected to the base ends 31L, 31R, and extension portions 36L, 36R extending substantially linearly from the detour portions 35L, 35R in a direction approaching the crucible 3.

[0039] The detour portions 35L, 35R can be provided at appropriate locations between the base ends 31L, 31R and a position above the crucible 3, in other words, a position overlapping the crucible 3 in a plan view. As shown in FIGS. 1 and 2 , the detour portions 35L, 35R of this embodiment have one end connected to the base ends 31L, 31R, and extend from the one end in a direction intersecting the above-mentioned line L, specifically, in the left-right direction, so as to move away from each other. It is also preferable that at least a portion of the detour portions 35L, 35R extends below the opening of the accommodation portion 3A of the crucible 3. By including the above-mentioned detour portions 35L, 35R in the pole pieces 21L, 22R, it becomes possible to easily route most of the pole pieces 21L, 22R to positions away from the upper portions of the target area TA and the high-temperature area HA. This allows most of the pole pieces 21L, 21R to be disposed at positions away from the target area TA, and makes it possible to prevent the evaporation material from adhering to and accumulating on the pole pieces 21L, 21R. Note that the first connecting portions 33L, 33R may also omit the detouring portions 35L, 35R when, for example, the housing 11 is sufficiently large in the left-right direction.

[0040] The extending portions 36L, 36R may extend linearly such that one end is connected to one end of the detour portions 35L, 35R and the other end is positioned past the target area TA in the front-to-rear direction. In this embodiment, the extending portions 36L, 36R extend in a direction substantially parallel to the straight line L. Note that the shape of the extending portions 36L, 36R may not be linear as described above, but may be bent or curved at one or more locations. Furthermore, the extending direction of the extending portions 36L, 36R may extend in a direction different from the extending direction of the straight line L.

[0041] The second connecting portions 34L, 34R connect the ends of the first connecting portions 33L, 33R and the tip portions 32L, 32R of the pair of pole pieces 21L, 21R, and form portions that extend in a second direction that intersects with the first direction along the straight line L. In this embodiment, the first direction corresponds to the front-rear direction, and the second direction corresponds to the left-right direction. In other words, the second connecting portions 34L, 34R can be said to be members that extend along the left-right direction.

[0042] As shown in FIGS. 1 and 2, the second connecting portions 34L and 34R are made of wide members with a relatively long length in the front-rear direction. Specifically, the length W1 of the second connecting portions 34L and 34R in the front-rear direction is longer rearward as viewed from the device body 10 than the length W2 of the tip portions 32L and 32R in the front-rear direction. In relation to this, a step 38 is formed at the rear of the tip portions 32L and 32R at the connecting portion of the second connecting portions 34L and 34R. The portions of the second connecting portions 34L and 34R that extend rearward beyond the rear ends of the tip portions 32L and 32R function as reflected electron deflection units 37L and 37R. The specific functions of the reflected electron deflection units 37L and 37R will be described later. In the present embodiment, the second connecting portions 34L, 34R have been exemplified as having the same length in the front-rear direction along their entire length in the left-right direction, but the lengths of the second connecting portions 34L, 34R in the front-rear direction do not have to be the same. In other words, the lengths of the second connecting portions 34L, 34R in the front-rear direction may differ depending on the left-right position.

[0043] In the deposition electron gun device 1 according to this embodiment, the electron beam EB emitted from the device body 10 is deflected in a desired direction by the action of the electron beam deflection means 20 including the above-described configuration. Specifically, as shown in FIG. 3 , when the electron beam EB is emitted from the electron beam source 12, it passes through the window 13 of the device body 10, and then its traveling direction is deflected by 180 to 270 degrees by the electron beam deflection means 20, and the electron beam EB is irradiated onto the target area TA. The evaporation material 2 located in the target area TA irradiated with the electron beam EB is heated and melted by the electron beam EB, vaporizes, and is evaporated onto the surface of a substrate serving as a coating member previously placed above the target area TA, thereby forming a thin film.

[0044] Another factor that can degrade the quality of a film formed on a coated member in a vacuum deposition apparatus, including an existing deposition electron gun device, is the collision of reflected electrons from the evaporation material with a thin film (evaporated film) on the coated member. Specifically, a portion of the electron beam irradiated on the evaporation material is not absorbed by the evaporation material, and the reflected electrons collide with the surface of a substrate (coating member) placed above the evaporation material, causing damage or deformation of the thin film at the collision site. Such damage or deformation is caused by the impact of the reflected electrons colliding with the thin film or by heat generated when the reflected electrons collide. In this embodiment, the shape of the pair of pole pieces 21L and 21R is devised to suppress the degradation of film formation quality due to the reflected electrons.

[0045] The deposition electron gun apparatus 1 according to this embodiment employs a structure in which the second connecting portions 34L, 34R are formed wide and provided with the reflected electron deflection portions 37L, 37R, as described above, in order to deflect, among the reflected electrons RE emitted from the target area TA, mainly those reflected toward the rear of the target area TA. The reflected electron deflection portions 37L, 37R are formed as part of the second connecting portions 34L, 34R of the pair of pole pieces 21L, 21R, and extend in a direction away from the apparatus body 10. When the reflected electron deflection portions 37L, 37R are magnetized by the magnetic source 22, a magnetic field can also be generated behind the tip portions 32L, 32R.

[0046] Furthermore, a distance L1 larger than the distance between the tip ends 32L, 32R may be formed between the reflected electron deflection units 37L, 37R. The distance L1 between the reflected electron deflection units 37L, 37R can be adjusted as appropriate, taking into consideration, for example, the width of the target area TA in the left-right direction and the magnitude of the magnetic field generated between the reflected electron deflection units 37L, 37R. Although Figure 2 and other figures illustrate an example in which the opposing surfaces of the reflected electron deflection units 37L, 37R are substantially parallel, the opposing surfaces do not have to be parallel.

[0047] The magnetic field generated by the reflected electron deflection units 37L, 37R mainly acts to deflect downward most of the reflected electrons RE that are emitted upward after being reflected by the electron beam EB irradiated onto the target area TA. As shown in FIG. 3, the reflected electrons RE deflected by the magnetic field generated by the reflected electron deflection units 37L, 37R emit upward from within the target area TA, then travel backward and downward so as to approach the upper surface of the crucible 3, moving so as to collide with any position on the crucible 3 one or more times. Each time the reflected electrons RE collide with the crucible 3, a portion of the reflected electrons RE is absorbed by the crucible 3. Thereafter, the same operation can be repeated one or more times.

[0048] As described above, in the deposition electron gun apparatus 1 according to this embodiment, the wide second connecting portions 34L and 34R allow a downward magnetic field to act on the back-reflected electrons RE emitted from the target area TA. This allows the back-reflected electrons RE to collide multiple times with components separate from the substrate, such as the crucible 3, thereby reducing their energy. Reducing the energy of the back-reflected electrons RE, which are part of the electron beam EB, prevents the back-reflected electrons RE from reaching the substrate, thereby avoiding or significantly reducing degradation of the film formation quality on the substrate due to the back-reflected electrons RE. While this embodiment illustrates the case where the back-reflected electrons RE collide with the top surface of the crucible 3, a cover member (not shown) may be provided on the top surface of the crucible 3 in advance, and the back-reflected electrons RE may collide with the surface of the cover member. The cover member may be a plate-shaped member capable of covering the top surface of the crucible 3, excluding the target area TA and the upper portion of the high-temperature area HA surrounding the target area TA. Furthermore, it is preferable to at least partially use a material capable of absorbing the energy of reflected electrons as the material for the cover member. By using such a cover member, it is possible to prevent the reflected electrons RE from colliding with the evaporation material 2 in the portion not located in the target area TA.

[0049] The above-described reflected electron deflection units 37L and 37R are primarily intended to apply a magnetic field to the reflected electrons RE reflected to the rear of the target area TA, but the reflected electrons RE may also be reflected in a direction other than the rear of the target area TA. For example, if a portion of the electron beam EB irradiated onto the target area TA is diffusely reflected, the reflected electrons RE may fly out in a direction other than the rear of the target area TA, for example, in the left-right direction. In the deposition electron gun device 1 according to this embodiment, a magnetic field generated around the extension units 36L and 36R can be used to deflect the reflected electrons RE flying out in the left-right direction.

[0050] The magnetic field generated around the extensions 36L and 36R mainly acts to deflect downward the reflected electrons RE that are scattered in the left and right directions and fly upward from the electron beam EB irradiated onto the target area TA. This action allows the scattered electrons RE that are scattered in the target area TA to collide with the crucible 3 and the like multiple times, thereby reducing their energy.

[0051] The magnetic field generated around the first connecting portions 33L and 33R depends on the magnetic field generated at the tip portions 32L and 32R. On the other hand, when deflecting the reflected electrons RE diffusely reflected from the target area TA, a stronger magnetic field generated around the first connecting portions 33L and 33R is preferable in terms of reducing the energy of the reflected electrons RE. Therefore, the following describes a deposition electron gun apparatus 1A according to a first modification of the first embodiment, which is modified in consideration of the above-mentioned points. Note that the components of the deposition electron gun apparatus 1A according to the first modification described below may be similar to the components of the deposition electron gun apparatus 1 according to the first embodiment, except for the partial shape of the pair of pole pieces 21LA and 21RA. Therefore, the following description will focus on the components that are different from those of the first embodiment, with the same reference numerals used to designate components similar to those of the deposition electron gun apparatus 1 according to the first embodiment.

[0052] FIG. 4 is a schematic perspective view showing a first modification of the deposition electron gun apparatus shown in FIG. 1. In the deposition electron gun apparatus 1A according to this modification, as shown in FIG. 4, the magnetic field generated around the pair of pole pieces 21LA and 21RA constituting the electron beam deflection means 20A is adjusted. More specifically, the magnitude of the magnetic field around the first connecting portions 33LA and 33RA is adjusted by adjusting the cross-sectional area of ​​the first connecting portions 33LA and 33RA of the pair of pole pieces 21LA and 21RA. In this modification, the aforementioned cross-sectional area adjustment is achieved by making the thickness of at least a portion of the first connecting portions 33LA and 33RA along a third direction thicker than the thickness of the tip portions along the third direction. Note that the aforementioned third direction corresponds to the up-down direction.

[0053] More specifically, in the deposition electron gun apparatus 1A according to this modification, the base ends of the extension portions 36LA, 36RA of the first coupling portions 33LA, 33RA and the second coupling portions 34LA, 34RA have thicker vertical thicknesses than the other portions including the tip portions 32L, 32R. Note that the vertical thicknesses of the base ends of the extension portions 36LA, 36RA and the second coupling portions 34LA, 34RA may be adjusted as appropriate depending on the magnitude of the magnetic field to be generated.

[0054] In the deposition electron gun apparatus 1A including the pair of pole pieces 21LA, 21RA as described above, the magnetic field generated around the extensions 36LA, 36RA can be made stronger than the magnetic field generated around other parts.

[0055] In the first modified example described above, the thickness of the first connecting portions 33LA and 33RA is adjusted to adjust the magnetic field generated around the first connecting portions 33LA and 33RA, but the same effect can be obtained by increasing the cross-sectional area of ​​the first connecting portions 33LA and 33RA. Therefore, the same effect can be obtained by, for example, increasing the width of the first connecting portions 33LA and 33RA in the left-right direction.

[0056] In the first modified example described above, the thickness of the first connecting portions 33LA and 33RA is adjusted to effectively deflect reflected electrons RE that are scattered from the target area TA mainly in the left and right directions. Below, a deposition electron gun apparatus 1B in which the shape of the pair of pole pieces is further improved will be described as a second modified example of the first embodiment described above. Note that, like the first modified example, the components of the deposition electron gun apparatus 1B according to the second modified example described below may be similar to the components of the deposition electron gun apparatus 1 according to the first embodiment described above, except for the partial shape of the pair of pole pieces 21LB and 21RB. Therefore, the following description will focus on the components that are different from those of the first embodiment, with the same reference numerals used to designate components that are similar to those of the deposition electron gun apparatus 1 according to the first embodiment, and their description will be omitted.

[0057] Fig. 5 is a schematic perspective view showing a second modified example of the deposition electron gun apparatus shown in Fig. 1. As shown in Fig. 5, the deposition electron gun apparatus 1B according to this modified example employs magnetic field adjustment pieces for adjusting the magnetic field at appropriate positions of a pair of pole pieces 21LB, 21RB constituting the electron beam deflection means 20B. Specifically, the pair of pole pieces 21LB, 21RB further includes one or more magnetic field adjustment pieces (for example, magnetic field adjustment pieces 41L, 41R, 42L, 42R described later) extending in a direction away from the target area TA from a portion where the second connecting portions 34LB, 34RB and the first connecting portions 33LB, 33RB are connected.

[0058] In this modified example, the one or more magnetic field adjustment pieces described above are exemplified by first magnetic field adjustment pieces 41L, 41R extending rearward from the ends of the second connecting portions 34LB, 34RB, and second magnetic field adjustment pieces 42L, 42R extending outward from the ends of the second connecting portions 34LB, 34RB along the left-right direction of a pair of pole pieces 21LB, 21RB.

[0059] The first magnetic field adjustment pieces 41L, 41R function to adjust the magnetic field in the rear region of the second connecting portions 34LB, 34RB, and mainly deflect reflected electrons RE that fly out to the left rear and right rear from the target area TA. The second magnetic field adjustment pieces 42L, 42R function to adjust the magnetic field in the outer region of the pair of pole pieces 21LB, 21RB, and mainly deflect reflected electrons RE that fly out to the left and right from the target area TA. The lengths along the extension direction and cross-sectional areas of the first magnetic field adjustment pieces 41L, 41R and second magnetic field adjustment pieces 42L, 42R may be adjusted taking into consideration the magnitude and range of the magnetic field generated around each magnetic field adjustment piece.

[0060] As in this modification, by providing magnetic field adjusting pieces 41L, 41R, 42L, and 42R extending in desired directions from a pair of pole pieces 21LB and 21RB, the magnetic field around the pole pieces 21LB and 21RB can be adjusted over a wide range, which effectively reduces the energy of the reflected electrons RE and significantly prevents a decrease in the quality of film deposition on the substrate due to collisions with the reflected electrons.

[0061] In the second modified example described above, the first magnetic field adjustment pieces 41L, 41R and the second magnetic field adjustment pieces 42L, 42R are exemplified as magnetic field adjustment pieces, but only one of these magnetic field adjustment pieces may be used. Furthermore, the shape of the magnetic field adjustment piece is not limited to one that extends linearly, but may also be one that is bent or curved at one or more points. Furthermore, the technical features described in the first and second modified examples described above may be used in combination.

[0062] <Second embodiment> In the second modified example described above, magnetic field adjustment pieces 41L, 41R, 42L, and 42R are used in a pair of pole pieces including the reflected electron deflection units 37L and 37R. However, the present disclosure is not limited to this. Therefore, as a second embodiment of the present disclosure, a deposition electron gun apparatus 1C including a pair of pole pieces including magnetic field adjustment pieces but not including the reflected electron deflection units 37L and 37R will be described below. Note that the configuration of the deposition electron gun apparatus 1C according to this embodiment may be similar to that shown in the second modified example or the first embodiment, except for the configuration of the second connecting unit. Therefore, the following description will focus on differences from the first embodiment or the second modified example, and configurations not described will be similar to those shown in the first embodiment or the second modified example.

[0063] Fig. 6 is a schematic perspective view showing an example of an evaporation electron gun apparatus according to a second embodiment of the present disclosure. As shown in Fig. 6, the evaporation electron gun apparatus 1C according to this embodiment includes an apparatus main body 10 including an electron beam source 12 and installed to the side of a crucible 3 that is open at the top and contains an evaporation material 2 to be evaporated onto a coating member, and a pair of pole pieces 21LC, 21RC that guide the electron beam EB irradiated from the apparatus main body 10 to a target area TA set in the crucible 3. Of these, the configuration of the apparatus main body 10 may be the same as that of the first embodiment. Furthermore, the pair of pole pieces 21LC, 21RC may be similar to the pair of pole pieces 21L, 21R of the first embodiment in that they include base ends 31L, 31R installed on the apparatus main body 10, tip ends 32L, 32R arranged above the crucible 3 and behind the target area TA, first connecting portions 33LC, 33RC extending in a direction approaching the tip ends 32L, 32R from the base ends 31L, 31R, and second connecting portions 34LC, 34RC connecting the ends of the first connecting portions 33LC, 33RC to the tip ends 32L, 32R and extending in the left-right direction.

[0064] On the other hand, the pair of pole pieces 21LC, 21RC of this embodiment are not particularly limited in the length in the front-rear direction of the second connecting portions 34LC, 34RC. Therefore, the length in the front-rear direction of the second connecting portions 34LC, 34RC may be adjusted to be substantially the same as the length in the front-rear direction of the tip portions 32L, 32R, as shown in FIG. 6. Therefore, the second connecting portions 34LC, 34RC of this embodiment do not substantially need to include the reflected electron deflection portions 37L, 37R of the first embodiment described above.

[0065] In addition, the pair of pole pieces 21LC, 21RC in this embodiment include one or more magnetic field adjustment pieces extending in a direction away from the target area TA from the portion where the second connecting portion 34LC, 34RC and the end of the first connecting portion 33LC, 33RC are connected.

[0066] 6, the magnetic field adjustment pieces in this embodiment are similar to those shown in the second modified example described above, that is, first magnetic field adjustment pieces 41L, 41R that adjust the magnetic field in the rear region of the second connecting portions 34LC, 34RC, and second magnetic field adjustment pieces 42L, 42R that adjust the magnetic field in the outer region of the pair of pole pieces 21LC, 21RC. Therefore, these first magnetic field adjustment pieces 41L, 41R and second magnetic field adjustment pieces 42L, 42R can deflect reflected electrons RE that fly out toward the rear of the second connecting portions 34LC, 34RC and toward the outside of the pair of pole pieces 21LC, 21RC.

[0067] As described above, the deposition electron gun apparatus 1C according to this embodiment can adjust the magnetic field around the pole pieces 21LC and 21RC, including around the bases of the second connecting portions 34LC and 34RC, over a wide range. This allows the reflected electrons RE to collide multiple times with components separate from the substrate, such as the crucible 3, thereby reducing their energy. Reducing the energy of the reflected electrons RE, which are part of the electron beam EB, can prevent the reflected electrons RE from reaching the substrate, thereby avoiding or significantly reducing degradation in the film formation quality on the substrate due to the reflected electrons RE.

[0068] The present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the present disclosure, all of which are included in the technical concept of the present disclosure. [Explanation of symbols]

[0069] 1, 1A, 1B, 1C Electron gun equipment for deposition 2 Evaporation material 3 Crucible 10. Device body 12 Electron beam source 20, 20A~20C Electron beam deflection means 21L, 21R, 21LA-21LC, 21RA-21RC pole pieces 31L, 31R proximal end 32L, 32R tip 33L, 33R, 33LA-33LC, 33RA-33RC First connecting part 34L, 34R, 34LA-34LC, 34RA-34RC Second connecting part 35L, 35R detour section 36L, 36R, 36LA, 36RA extension 37L, 37R Backscattered electron deflector 38 Step part 41L, 41R: First magnetic field adjusting piece (an example of a magnetic field adjusting piece) 42L, 42R: Second magnetic field adjusting piece (an example of a magnetic field adjusting piece) EB electron beam RE backscattered electron

Claims

1. an apparatus body provided with an electron beam source and disposed beside a crucible having an open top and containing an evaporation material to be deposited on the coating member; a pair of pole pieces made of a ferromagnetic material that guide the electron beam emitted from the device body to a target area set in the crucible; The pair of pole pieces are a base end portion installed in the device body; a tip portion disposed above the crucible and behind the target region as viewed from the apparatus body; a first connecting portion extending from the base end portion toward the tip end portion; a second connecting portion that connects an end of the first connecting portion and the tip portion and extends in a second direction that intersects with a first direction along a straight line connecting the device body and the target area, wherein the length of the second connecting portion in the first direction is longer in a direction away from the device body than the length of the tip portion in the first direction; Electron gun device for evaporation.

2. a thickness of at least a part of the first connecting portion along a third direction intersecting the first direction and the second direction is thicker than a thickness of the tip portion along the third direction; 2. The deposition electron gun device according to claim 1.

3. The pair of pole pieces are Further provided is one or more magnetic field adjustment pieces extending in a direction away from the target area from a portion where the second connecting portion and the end of the first connecting portion are connected.

2. The deposition electron gun device according to claim 1.

4. an apparatus body provided with an electron beam source and disposed beside a crucible having an open top and containing an evaporation material to be deposited on the coating member; a pair of pole pieces for guiding the electron beam emitted from the apparatus body to a target area set in the crucible; The pair of pole pieces are a base end portion installed in the device body; a tip portion disposed above the crucible and behind the target region as viewed from the apparatus body; a first connecting portion extending from the base end portion toward the tip end portion; a second connecting portion that connects the end portion of the first connecting portion and the tip portion and extends in a second direction that intersects with a first direction along a straight line connecting the device body and the target area; one or more magnetic field adjustment pieces extending in a direction away from the target area from a portion where the second connecting portion and the end of the first connecting portion are connected; Electron gun device for evaporation.

5. the first connecting portion includes a detour portion extending in a direction away from the target area; 5. The deposition electron gun device according to claim 1.

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