JP2013069661A - Electrode frame body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve work efficiency when replacing the electrode rod of a charged particle beam extraction electrode.SOLUTION: The extraction electrode is configured of a slit electrode 1 having a slit-like aperture 4. The slit electrode 1 consists of an electrode frame 2 and electrode rods 5. The electrode frame 2 has an integral structure and includes an aperture 3 for passing a charged particle beam and groove-like electrode supports. The electrode rods 5 are arranged on the electrode frame 2 while straddling over the aperture 3 and supported, at both ends thereof, by the electrode supports, thus forming the slit-like aperture 4.

Description

  The present invention relates to an electrode frame that constitutes a beam extraction electrode used in a charged particle beam generator such as an ion source of an ion beam irradiation apparatus or an electron source of an electron beam irradiation apparatus.

  Conventionally, a slit electrode having a plurality of slit-like openings (rectangular openings) has been used as an extraction electrode system for extracting an ion beam from an ion source of an ion beam irradiation apparatus. The slit-shaped opening of such a slit electrode is heated to a high temperature by being exposed to plasma or colliding with the extracted ion beam.

  When the slit-like opening is heated to a high temperature, it causes thermal deformation. When the distortion of the slit-shaped opening due to thermal deformation becomes large, for example, an ion beam having a desired beam amount cannot be extracted. As a result, parts must be replaced.

  Even if the parts are replaced, the cost increases if the entire slit electrode is replaced. For this reason, there is a demand for exchanging only a part having a particularly large distortion among the parts constituting the plurality of slit-shaped openings.

  In order to meet such a demand, a slit electrode described in Patent Document 1 has been devised so far.

  Patent Document 1 discloses a slit electrode in which members constituting the slit-like opening of the slit electrode can be partially exchanged.

  FIG. 2 of Patent Document 1 discloses a configuration of a plasma electrode (also referred to as an acceleration electrode) used in an extraction electrode system of an ion source. In this plasma electrode, a plurality of electrode rods are arranged in the opening of the electrode frame, so that slit-like openings are formed between the electrode rods. Each electrode rod is attached to and detached from the electrode frame by being individually inserted and removed from the outside of the electrode frame through a through hole formed in the electrode frame.

  FIG. 3 of Patent Document 1 shows an example of a suppression electrode and a ground electrode that constitute the extraction electrode system. Similar to the example of FIG. 2, the slit-shaped opening is configured by arranging a plurality of electrode rods in the opening of the electrode frame. In the example of FIG. 3, the electrode frame is composed of two frames. By combining the two frames with the end of the electrode rod inserted into the hole provided in each frame. Assembling of the slit electrode is performed. On the other hand, when the slit electrode is disassembled, the two frames are disassembled, and a plurality of electrode bars are removed from the holes of each frame.

Japanese Examined Patent Publication No. 7-34358 (FIG. 2, FIG. 3, (2) 4 33rd line to (3) 5 40th line)

  Usually, not only one electrode rod constituting the slit electrode is distorted, but a plurality of electrode rods arranged in a certain region are distorted. Therefore, it is necessary to exchange them together.

  However, in the configuration of the electrode described in FIG. 2 of Patent Document 1, it takes time because the electrode rods are replaced by being inserted into and removed from the electrode frame one by one along the length direction. End up.

  Further, in the configuration of the electrode described in FIG. 3 of Patent Document 1, a plurality of electrode rods can be replaced together, but the electrode frame must always be disassembled regardless of the number of electrode rods to be replaced. The work efficiency is poor. In particular, when the size of the ion source is large, the electrode frame is also large, and therefore, the disassembly work requires a lot of time and labor.

  The main object of the present invention is to improve the working efficiency when replacing the electrode rod forming the slit-like opening of the extraction electrode.

  The electrode frame of the present invention is an electrode frame that constitutes an electrode for extracting a charged particle beam, and the electrode frame has an opening that allows a charged particle beam to pass through in a substantially central part, and the electrode When the frame is viewed from one direction, an electrode rod support portion that supports both ends of the electrode rod disposed across the opening is formed in a part around the opening.

  If such a structure is employ | adopted, an electrode rod can be easily attached to an electrode frame from the direction substantially orthogonal to the length direction. In addition, since it is not necessary to disassemble the electrode frame, the time required to replace the electrode rod can be greatly shortened.

  More specifically, the electrode rod support portion is formed on the surface of the electrode frame and is recessed in a groove shape from the surface.

  Moreover, it is desirable that the electrode rod support portion is connected to the opening.

  In addition, it is desirable that a lid is attached above the electrode rod support.

  On the other hand, the charged particle beam generator is provided with a beam extraction electrode composed of the electrode frame.

  Since the electrode rod can be attached to the electrode frame from a direction substantially orthogonal to the length direction, the replacement work is simplified. Moreover, since it is not necessary to disassemble the electrode frame when exchanging the electrode rod, the time required for exchanging the electrode rod can be greatly shortened.

It is a top view showing an example of the slit electrode of this invention. It is a top view showing a mode when a cover body and an electrode stick | rod are removed from the slit electrode of FIG. It is a principal part enlarged view of FIG. 2, and represents a mode when an electrode rod is arrange | positioned at an electrode rod support part. It is a principal part enlarged view of FIG. 2, and represents a mode when a cover body has been arrange | positioned on an electrode bar support part.

  In the following embodiments, the X, Y, and Z axes depicted in the drawings are orthogonal to each other.

  FIG. 1 shows an example of the slit electrode 1 of the present invention. The slit electrode 1 is mainly composed of an electrode frame 2 having an opening 3 and a plurality of electrode rods 5 (members hatched in the drawing) disposed in the opening 3.

  The electrode rods 5 are supported by the electrode frame 2 so that the longitudinal direction is along the X direction, and are arranged in parallel at substantially equal intervals along the Y direction.

  A slit-shaped opening 4 is formed between the electrode rods 5 arranged substantially along the Y direction or between the electrode rods 5 positioned at the ends in the Y direction and the electrode frame 2. . In FIG. 1, FIG. 7 and FIG. 8 to be described later, the electrode rod 5 and the slit-like opening 4 are only partially indicated for simplification of the drawing.

  The state when the electrode rod 5 and the lid 6 are removed from the slit electrode 1 shown in FIG. 1 is depicted in FIG. The plurality of electrode rods 5 are supported at both ends in the longitudinal direction by the electrode rod support portion 7 shown in FIG. 2 arranged opposite to each other along the X direction across the opening 3 of the electrode frame 2. Yes. As an example, the electrode rod support portion 7 is formed by cutting out an end portion adjacent to the opening 3 of the electrode frame 2 into a rectangular shape.

  The lid body 6 shown in FIG. 1 is attached to the upper surface of the electrode rod support portion 7 shown in FIG. 2 from the Z direction side. A through hole (not shown) is formed in the lid body 6. A set screw 8 is inserted into the through hole of the lid body 6 from the Z direction side and is screwed into the screw hole 9 of the electrode frame body 2. 6 is attached.

  The lid body 6 shown in FIG. 1 is divided into a plurality of parts along the direction in which the electrode rods 5 are arranged in parallel (approximately the Y direction in the figure). Also good. In the case of one lid body 6, the mounting operation of the lid body 6 becomes simple. Further, since thermal expansion occurs in the lid body 6, it is desirable to use a high melting point material such as molybdenum or tungsten having a low thermal expansion coefficient for the lid body 6.

  When thermal expansion occurs in the lid body 6, if the single large lid body 6 is used, the elongation of the lid body 6 due to thermal expansion also increases. On the other hand, if the lid body 6 is divided, the lid body 6 can be made smaller than the one large lid body 6 so as to allow the elongation due to thermal expansion of the lid body 6. Further, if the lid body 6 is divided and provided, only the lid body having a large thermal deformation can be replaced, so that it can be expected that the cost for the replacement of the member can be reduced.

  FIG. 3 is an enlarged view of a main part of FIG. 2, and shows a state in which the electrode rod 5 is disposed on the electrode rod support portion 7. In the X direction and the Y direction, the relationship between the dimension of the electrode bar 5 and the dimension between the pair of electrode bar support portions 7 arranged in the X direction is set to satisfy R1X <LX <R2X and LY ≦ RY. Yes. In the Z direction, the dimensional relationship between the electrode rods 5 is set so that the electrode rods 5 fit within the electrode rod support portion 7. However, it is not limited to this. For example, when a counterbore is provided in a part of the lid 6 that covers the upper part of the electrode bar support portion 7 and a part of the electrode bar 5 is accommodated therein, the electrode bar 5 is an electrode bar. It does not have to be within the support portion 7.

  In FIG. 3, the electrode rod support portion 7 is formed on the electrode frame 2. In that case, since the special member which comprises the electrode stick | rod support part 7 is not required, it can be anticipated that the member cost will be reduced.

  However, the vicinity where the electrode rod support portion 7 is formed is heated to a relatively high temperature by being exposed to plasma or colliding with an ion beam. Therefore, there is a possibility that the electrode rod support portion 7 is thermally deformed. When the electrode rod support 7 is thermally deformed, the electrode frame 2 must be replaced in the example of FIG. Although depending on the size of the ion source, since the electrode frame 2 is a relatively large member, the cost of the member is high accordingly.

  FIG. 4 is an enlarged view of a main part of FIG. 2, and shows a state where the lid body 6 is arranged on the electrode rod support portion 7. As can be understood from this figure, when the lid 6 is arranged on the upper surface of the electrode rod support portion 7, the open end 13 is formed on the electrode rod support portion 7 in the X direction which is the longitudinal direction of the electrode rod 5. With such a configuration, it is possible to prevent the end of the electrode rod 5 from coming off from the electrode rod support portion 7.

  The opening 3 formed in the electrode frame 2 to which the present invention is applied need not be rectangular, and may have other shapes. For example, a circular shape, an elliptical shape, or a polygonal shape may be used, and when the electrode rod 5 is disposed in the opening 3, the slit-shaped opening 4 through which the ion beam passes is formed. Any shape is acceptable.

  As a material of the electrode rod 5, it is considered that a high melting point material (for example, molybdenum or tungsten) is used because it is heated to a high temperature.

  In the above-described embodiment, the example in which the electrode frame of the present invention is applied to the ion beam extraction electrode of the ion source used in the ion beam irradiation apparatus has been described, but the electron source used in the electron beam irradiation apparatus is The electrode frame of the present invention may be applied to an electrode for extracting an electron beam. In the electron source, as in the case of the ion source, there is a problem that the electrode portion is heated when the electron beam is drawn out. Therefore, the electrode frame of the present invention can be applied.

  In addition to the above, it goes without saying that various improvements and modifications may be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Slit electrode 2 ... Electrode frame 3 ... Opening part 4 ... Slit-like opening part 5 ... Electrode bar 6 ... Cover body 7 ... Electrode bar support part 8 ...・ Set screw 9 ... Screw hole 13 ... Open end

Claims (5)

An electrode frame constituting an electrode for extracting a charged particle beam,
The electrode frame has an opening that allows a charged particle beam to pass through in a substantially central part,
When the electrode frame is viewed from one direction, an electrode rod support portion that supports both ends of the electrode rod disposed across the opening is formed in a part around the opening. Electrode frame.   2. The electrode frame according to claim 1, wherein the electrode bar support portion is formed on a surface of the electrode frame and is recessed in a groove shape from the surface.   The electrode frame according to claim 1, wherein the electrode bar support portion is connected to the opening.   The electrode frame according to any one of claims 1 to 3, wherein a lid is attached above the electrode rod support portion. A charged particle beam generator comprising an extraction electrode comprising the electrode frame according to claim 1.

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