Ion beam source assembly

Abstract

An ion beam source assembly according to an embodiment of the present invention comprises an anode electrode and a cathode electrode arranged in a stacked structure by forming a first gap on the anode electrode, wherein the cathode electrode comprises a first cathode electrode and a second cathode electrode, and the first cathode electrode and the second cathode electrode each form a first gap with the anode electrode, and the first cathode electrode and the second cathode electrode are spaced apart by forming a second gap, and a plasma groove is formed on the anode electrode at a position corresponding to the position of the second gap formed by the first cathode electrode and the second cathode electrode.

Description

Technology Field

[0001] The present invention relates to an ion beam source assembly, and more specifically, to an anode ion beam source assembly. Background Technology

[0002] Generally, an ion beam source applies voltage to an anode and a cathode spaced apart at a certain distance and injects gas into the spaced space to generate plasma, and accelerates ions from the plasma with an electric field to extract them in the form of a beam. The ion beam technology is broadly divided into a method that generates plasma using a filament or RF frequency and then accelerates and extracts ions through a separate acceleration electrode, and an extraction method with a structure capable of simultaneously generating plasma and accelerating ions.

[0003] In the case of extraction methods with a structure capable of simultaneously generating plasma and accelerating ions, a closed-drift ion source utilizing electrons undergoing closed-loop motion is primarily employed. This closed-drift ion beam source allows for easy linear expansion of the ion extraction region and, due to its simple structure, is used in various surface treatment industries.

[0004] In order to utilize the above linear ion beam source in a high-speed surface treatment process, the amount of ions or active species generated from the linear ion beam source must be large. Generally, the generation of ions and active species can be increased by increasing the discharge power and current.

[0005] In the above linear ion beam source, the discharge current increases as the distance between the anode and cathode widens. However, if the distance between the anode and cathode widens beyond a certain distance, the space outside the plasma discharge space for ion beam extraction expands, leading to unwanted dielectric breakdown. Consequently, flow instability of the plasma is caused, resulting in abnormal discharge and consequently, the operational stability of the ion beam source deteriorates.

[0006] In addition, the discharge current and power can be improved by expanding the discharge space under the same voltage conditions. When the discharge space is expanded, the space in which electrons confined and moving by the magnetic field can collide with neutral particles increases, thereby relatively increasing the discharge current. However, if the discharge space is expanded excessively, or if the space between the positive and negative electrodes is expanded in the non-discharge region, it may result in abnormal discharge or unstable discharge.

[0007] Furthermore, as the ion beam is ejected, the cathode is etched or sputtered, changing the gap and shape between the cathodes, or a problem arises where sputtered particles contaminate the sample irradiated by the ion beam. In particular, as the cathode is etched or sputtered and its shape changes, the emission pattern and amount of the ion beam change, which can cause the ion source to become unstable.

[0008] Therefore, an ion beam source assembly capable of guaranteeing the stability of the ion beam source is essential for the ion beam's lifetime and for reducing particles on substrates undergoing deposition or surface treatment. Prior art literature

[0009] U.S. Patent No. 7425709 (September 16, 2008) Republic of Korea Patent No. 2075157 (February 3, 2020) The problem to be solved

[0010] The objective of the present invention is to provide an ion beam source assembly with improved straightness so that the ion beam does not collide with the cathode electrode. means of solving the problem

[0011] An ion beam source assembly according to an embodiment of the present invention comprises an anode electrode and a cathode electrode arranged in a stacked structure by forming a first gap on the anode electrode, wherein the cathode electrode comprises a first cathode electrode and a second cathode electrode, and the first cathode electrode and the second cathode electrode each form a first gap with the anode electrode, and the first cathode electrode and the second cathode electrode are spaced apart by forming a second gap, and a plasma groove is formed on the anode electrode at a position corresponding to the position of the second gap formed by the first cathode electrode and the second cathode electrode.

[0012] An ion beam source assembly with this structure can reduce the gap between the cathode electrode and the anode electrode, thereby improving the straightness of the ion beam.

[0013] In addition, according to an embodiment of the present invention, the third gap constituting the open entrance of the plasma groove is formed to be narrower than the second gap. By forming the third gap to be narrower than the second gap, the sputtering phenomenon in which radially emitted ions collide with the cathode electrode can be reduced.

[0014] In addition, according to an embodiment of the present invention, the cross-section of the plasma groove may be formed in a polygonal or circular shape. The shape of the cross-section of the plasma groove is related to the shape of the emitted ion beam and the intensity of the ions, and may affect the electric field formed by the voltage applied to the anode.

[0015] In addition, according to an embodiment of the present invention, the mutually opposing surfaces of the first cathode electrode and the second cathode electrode are formed as inclined surfaces, and the cathode electrode may have an ion beam emission portion formed in a shape that is wider at the top and narrower at the bottom, including a second gap.

[0016] The sputtering phenomenon that may occur on the cathode electrode can be reduced by the inclined surface formed on the first cathode electrode and the second cathode electrode and the second gap.

[0017] In addition, according to an embodiment of the present invention, the first cathode electrode and the second cathode electrode may each have a surface facing the anode electrode that is parallel.

[0018] Since the plasma density point formed between the first cathode electrode and the anode electrode of the second cathode electrode is generated in the aforementioned plasma groove, it can be maintained at a constant first interval to improve the straightness of the ion beam and reduce collisions with the cathode.

[0019] In addition, according to an embodiment of the present invention, the first gap may be less than 1 mm. Even if the first gap is less than 1 mm, a cathode sheath and an anode sheath may be formed in the plasma groove, and plasma is formed.

[0020] In addition, according to an embodiment of the present invention, a supply gas injection unit for supplying gas to the cathode electrode is further included. By supplying gas to the cathode electrode, the cathode electrode in a ground state can form a circuit configuration that stably maintains the plasma, and a stable plasma floating from the electrically grounded cathode electrode can be formed to apply a high voltage to the anode electrode. In addition, the need to secure an insulating structure in the ion beam source assembly is reduced, so the structure can be implemented relatively simply. Effects of the invention

[0021] According to the ion beam source assembly according to an embodiment of the present invention, it is possible to irradiate an ion beam with improved straightness.

[0022] In addition, it can prevent the negative electrode (cathode electrode) from being etched.

[0023] In addition, the lifespan of the ion beam source is extended.

[0024] Further scopes of the applicability of the present invention will become apparent from the following detailed description. However, since various changes and modifications within the spirit and scope of the present invention are clearly understood by those skilled in the art, specific embodiments, such as the detailed description and preferred embodiments of the present invention, should be understood as being given merely as examples. Brief explanation of the drawing

[0025] FIG. 1 is a perspective view of an ion beam source assembly according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of an ion beam source assembly according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of an ion beam source assembly according to an embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of an ion beam source assembly according to an embodiment of the present invention. Specific details for implementing the invention

[0026] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed herein are provided merely for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described herein.

[0027] Terms such as "first" or "second" may be used to describe various components, but said components should not be limited by said terms. For the sole purpose of distinguishing one component from another, for example, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0028] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Expressions describing the relationships between components, such as "between," "exactly between," or "directly adjacent to," should be interpreted in the same way.

[0029] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0030] Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, the scope of the patent application is not limited or restricted by these embodiments. Identical reference numerals in each drawing indicate identical components.

[0031] FIG. 1 is a perspective view of an ion beam source assembly according to an embodiment of the present invention.

[0032] FIG. 2 is an exploded perspective view of an ion beam source assembly according to an embodiment of the present invention.

[0033] FIG. 3 is a cross-sectional view of an ion beam source assembly according to an embodiment of the present invention.

[0034] FIG. 4 is an enlarged cross-sectional view of an ion beam source assembly according to an embodiment of the present invention.

[0035] As illustrated in FIGS. 1 and 2, an ion beam source assembly according to an embodiment of the present invention comprises an anode electrode (100) and a cathode electrode (200) arranged in a stacked structure by forming a first gap (20) on the anode electrode (100), wherein the cathode electrode (200) comprises a first cathode electrode (210) and a second cathode electrode (220), wherein the first cathode electrode (210) and the second cathode electrode (220) each form the first gap (20) with the anode electrode (100), and the first cathode electrode (210) and the second cathode electrode (220) are spaced apart by forming a second gap (30), and the anode electrode (100) is formed by the first cathode electrode (210) and the second cathode electrode (220). A plasma groove (110) is formed at a position corresponding to the position of the second interval (30).

[0036] An ion beam source assembly according to an embodiment of the present invention has a plasma groove (110) formed in the anode electrode (100) to reduce sputtering of the cathode electrode (200) by plasma ions and ensure the straightness of the ion beam.

[0037] An ion beam source assembly according to an embodiment of the present invention illustrated in FIGS. 1 to 3 can be implemented in a stacked form comprising a main body (10), an anode electrode (100), a cathode electrode (200), and a magnet (300).

[0038] That is, it can be configured such that a hollow cylindrical body (10) with an open top, an anode electrode (100) and a magnet (300) stacked inside the body (10) are mounted, and a cathode electrode (200) is coupled to the open top of the body (10).

[0039] The main body (10) has a fastening rod (11) protruding from the center inside, and a blocking part (13, 14) for separating the magnet (300) and the anode electrode (100) may be formed on the outside of the fastening rod (11).

[0040] The center of a donut-shaped magnet (300) can be attached to the connecting rod (11), and the center of a donut-shaped anode electrode (100) can be attached to the outer surface of the blocking part (13, 14).

[0041] The blocking portion (13, 14) is positioned along the outer side of the donut-shaped magnet (300) in a manner that surrounds the magnet (300), and the blocking portion (13, 14) functions to separate the magnet (300) from the anode electrode (100).

[0042] As illustrated in FIGS. 2 and 3, the blocking section (13, 14) can be distinguished into a first blocking section (13) and a second blocking section (14). The first blocking section (13) is in direct contact with the outer surface of the magnet (300), and the second blocking section (14) is formed on the outer side of the first blocking section (13). A supply gas injection section (17) may be formed between the first blocking section (13) and the second blocking section (14).

[0043] The blocking section (13, 14) shown in FIGS. 2 and 3 is designed such that the supply gas injection section (17) injects supply gas into the cathode electrode (200), but the ion beam source assembly according to the embodiment of the present invention is not necessarily limited thereto.

[0044] The main body (10) has a side guide (12) formed on its side, and a space is formed between the side guide (12) and the blocking part (13, 14).

[0045] The anode electrode (100) may be configured in the shape of a donut-shaped circular plate as shown in FIG. 2. The anode electrode (100) is located in the space formed between the aforementioned side guide (12) and the blocking parts (13, 14). An external power source is connected to the anode electrode (100) and acts as an energy source for emitting an ion beam.

[0046] The anode electrode (100) is seated in a space formed inside the main body (10) and is firmly connected to the main body (10) by bolting. A plasma groove (110) is formed on the upper surface of the anode electrode (100).

[0047] A detailed description of the plasma groove according to an embodiment of the present invention will be provided later.

[0048] The cathode electrode (200) includes a first cathode electrode (210) and a second cathode electrode (220).

[0049] The first cathode electrode (210) has a cone shape with its upper end cut off, and a first slope (211) is formed along an arc. In particular, the first cathode electrode (210) is installed so that it is seated on the upper part of the first blocking part (13) and a first gap (20) can be formed with the anode electrode (100).

[0050] A magnet (300) is located at the lower center of the first cathode electrode (210).

[0051] The second cathode electrode (220) has a donut shape and a second bevel (221) formed inside, and is installed in a position facing the first bevel (211) of the first cathode electrode (210).

[0052] In particular, the second cathode electrode (220) is fitted into a protruding ring (15) formed on the upper side guide (12) of the main body (10) and is firmly connected to the main body (10) by bolting.

[0053] The second cathode electrode (220) is placed on the upper side guide (12) of the main body (10) and is fixed, and a first gap (20) can be formed with the anode electrode (100) installed at the lower side.

[0054] That is, the first cathode electrode (210) and the second cathode electrode (220) each have a surface facing the anode electrode (100) that is parallel to the first gap (20).

[0055] The first slope (211) and the second slope (221), which are mutually opposing regions of the first cathode electrode (210) and the second cathode electrode (220), have a tapered shape, and the gap between the edge regions of the first slope (211) and the second slope (221) forms a second gap (30).

[0056] This is to prevent sputtering of the first cathode electrode (210) and the second cathode electrode (220) by the ion beam emitted in a radial form.

[0057] As shown in FIG. 1, a circular space band is formed on the upper part of the ion beam source assembly according to an embodiment of the present invention by the first cathode electrode (210) and the second cathode electrode (220).

[0058] The tapered circular space band region, which is wider at the top and narrower at the bottom, is an ion beam emission section (400) where an ion beam is emitted.

[0059] Additionally, as shown in FIGS. 3 and 4, a plasma groove (110) formed on the upper part of the anode electrode (100) is located at the lower part of the circular space band, and the third gap (40), which is the opening gap of the plasma groove (110), is formed narrower than the second gap (30). As the third gap (40) is formed narrower than the second gap (30), ions emitted from the plasma density point formed near the plasma groove (110) do not collide with the first cathode electrode (210) and the second cathode electrode (220).

[0060] In an ion beam source assembly according to an embodiment of the present invention, the first gap (20), which is the gap between the anode electrode (100) and the cathode electrode (200), is less than 1 mm.

[0061] A typical ion beam source is 10 -4 It must operate at Torr pressure, and a space must be secured between the cathode and anode electrodes for plasma formation. This space includes the region called the cathode sheath in the cathode electrode area and the anode sheath in the anode electrode area.

[0062] A gap including the cathode sheath and anode sheath regions must be secured in the space between the cathode electrode and the anode electrode, and the ion beam source currently in use forms a gap of about 3 mm.

[0063] In this way, plasma density is maintained by a magnetic field formed by a magnet within the gap between the cathode electrode and the anode electrode, power is applied to the anode electrode, and an ion beam is emitted due to the potential difference between the cathode electrode and the anode electrode.

[0064] In a driving circuit where electrons and ions move, a Cathode Sheath and an Anode Sheath exist between the cathode and anode electrodes, which are regions of high ion and electron density at each electrode; the gap between the cathode and anode electrodes must be sufficient to include these Cathode Sheaths and Anode Sheaths, providing a space where plasma can be formed.

[0065] 10 -4 In a typical ion source with a counter electrode shape driven at Torr pressure, the gap between the cathode electrode and the anode electrode is preferably about 3 mm, and if a gap of about 3 mm is not formed, plasma is not formed.

[0066] Conversely, if the gap between the cathode electrode and the anode electrode exceeds 3 mm, the plasma generation space increases, resulting in a larger number of generated ions. However, as the ions accelerate and collide with the cathode electrode, there are more ions sputtering the cathode electrode than ions emitting outward, making it inefficient. In the long term, the cathode electrode is sputtered, reducing its lifespan and causing the shape of the cathode electrode to deform, preventing the ion beam from emitting normally.

[0067] However, in the ion beam source assembly according to the embodiment of the present invention, a plasma groove (110) is formed on the upper part of the anode electrode (100), so that plasma is formed even though the gap between the cathode electrode (200) and the anode electrode (100) is less than 1 mm.

[0068] According to the ion beam source assembly according to an embodiment of the present invention, plasma is not formed in the first gap (20), which is the gap between the cathode electrode (200) and the anode electrode (100), and plasma is formed in the plasma groove (110), which is a space formed on the upper part of the anode electrode (100).

[0069] An ion beam is emitted from the second gap (30), which is the gap between the first cathode electrode (210) and the second cathode electrode (220), with the intensity of the potential applied to the anode electrode (100) while the plasma is maintained by the magnetic field formed by the magnet (300).

[0070] The cross-section of the plasma groove (110) according to an embodiment of the present invention may be polygonal or circular in shape and may be implemented in various shapes. In particular, the depth of the plasma groove (110) affects the straightness of the ion beam by the potential applied to the anode electrode (100).

[0071] Furthermore, the spatial size (volume) of the plasma home (110) has the effect of increasing the volume of the plasma being formed, thereby increasing the amount of ions emitted to the outside.

[0072] However, the spatial size of the plasma home (110) can be optimized according to the strength of the applied voltage and magnetic field, and if an excessively large space is formed that does not match these factors, plasma may not be generated or may become an unstable plasma state, and an arc may occur.

[0073] Therefore, it is desirable to determine the spatial size of the optimized plasma home (110) by considering the magnetic force strength of the magnet (300) mounted on the ion beam source and the voltage strength applied to the anode electrode (100).

[0074] An ion beam source assembly according to an embodiment of the present invention includes a supply gas injection unit (17) that provides a supply gas, and the supply gas injection unit (17) provides a supply gas to a cathode electrode (200).

[0075] When a supply gas is injected into the anode electrode (100), the ionization rate increases, thereby increasing the concentration of ions formed in the plasma groove (110). However, if the ion beam source assembly is designed with a structure that injects a supply gas into the anode electrode (100), there is a difficulty in forming a complex insulation structure inside the assembly. In addition, it is difficult to apply high voltage because an arc occurs.

[0076] An ion beam source assembly according to an embodiment of the present invention can supply a supply gas to a cathode electrode (200). A supply gas injection unit (17) for supplying the supply gas to the cathode electrode (200) is connected, and in this case, a high voltage can be applied and can be implemented with a simple structure.

[0077] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0078] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

Claim 1 An ion beam source assembly comprising: an anode electrode; and a cathode electrode arranged in a stacked structure by forming a first gap in the anode electrode, wherein the cathode electrode comprises a first cathode electrode and a second cathode electrode, wherein the first cathode electrode and the second cathode electrode each form a first gap with the anode electrode, and the surface of each of the first cathode electrode and the second cathode electrode facing the anode electrode is parallel to the first gap, and the first cathode electrode and the second cathode electrode are spaced apart by forming a second gap, and wherein a plasma groove is formed in the anode electrode at a position corresponding to the position of the second gap formed by the first cathode electrode and the second cathode electrode. Claim 2 An ion beam source assembly according to claim 1, characterized in that the third gap constituting the open entrance of the plasma groove is narrower than the second gap. Claim 3 An ion beam source assembly according to claim 1, characterized in that the cross-section of the plasma groove is polygonal or circular in shape. Claim 4 An ion beam source assembly according to claim 1, wherein the mutually opposing surfaces of the first cathode electrode and the second cathode electrode are formed as inclined surfaces, and the cathode electrode is formed with an ion beam emission portion having a shape that is wider at the top and narrower at the bottom, including a second gap. Claim 5 An ion beam source assembly according to claim 4, wherein each of the first cathode electrode and the second cathode electrode has a surface facing the anode electrode that is parallel. Claim 6 An ion beam source assembly according to claim 1, characterized in that the first gap is less than 1 mm. Claim 7 An ion beam source assembly according to claim 1, further comprising a supply gas injection unit that provides a supply gas to the cathode electrode.

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