JPH07302700A - High frequency quadrupole accelerator - Google Patents

Abstract

PURPOSE:To provide a high frequency quadrupole accelerator in which specific charged particles only can be accelerated and outputted by composing a resonance circuit in a metal casing to form an acceleration cavity, and supplying high frequency power combined with a DC voltage to quadrupole electrodes. CONSTITUTION:Metal bodies 21-24 are disposed to be close to each other between two pairs of mutually facing electrodes of quadrupole electrodes 11-14 in which the two pairs of the electrodes are disposed in directions of a cross, so a resonance circuit is formed in a metal casing 16 composing an acceleration cavity to compose an RFQ acceleration device which is stable electrically and mechanically, which has a low Q-value, and in which high frequency loss is small. Simultaneously, a DC voltage combined with high frequency power is applied between the two pairs of the mutually facing electrodes, and a ratio between the high frequency voltage and the DC voltage is kept constant, while the respective voltages are changed, so the quadrupole electrodes 11-14 achieve functions of a quadrupole mass filter, thereby a specific sort of ions only can be transmitted through the acceleration cavity.

Description

Translated fromJapanese

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は，半導体プロセス，医
療，バイオ技術等の分野に利用される荷電粒子加速器に
係り，詳しくは，高周波四重極電極により荷電粒子を高
エネルギービームに加速して，イオン注入，組成分析，
表面改質等の用に供する高周波四重極加速装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle accelerator used in the fields of semiconductor processing, medical treatment, biotechnology and the like, and more specifically, it accelerates charged particles into a high energy beam by a high frequency quadrupole electrode. , Ion implantation, composition analysis,
The present invention relates to a high-frequency quadrupole accelerator used for surface modification and the like.

【０００２】[0002]

【従来の技術】上記高周波四重極加速装置は，周知の通
り高周波電界を発生する４個のベイン電極（四重極電
極）の間に入射された荷電粒子を上記高周波電界により
加速させるように構成された加速器である。この高周波
四重極（Radio Frequency Quadrupole）加速装置（以下
ＲＦＱ加速装置と呼称する）の基本的な構成及び動作に
ついて以下に示す。図８に示すＲＦＱ加速装置は，筒状
の金属筐体５の中心軸方向に四重極電極を形成する電極
１，２，３，４が配設され，各電極１，２，３，４は互
いに向き合った面が凹凸状に波打った形状に形成され，
互いに向かい合った電極では凹凸形状が同位相に形成さ
れており，互いに隣合った電極では凹凸形状が逆位相に
形成されている。このように形成された四重極電極に，
図９に示すように互いに向かい合った電極には同位相，
互いに隣合った電極には逆位相の高周波電圧を印加する
と，４個の電極１，２，３，４が向かい合う中心軸付近
では四重極電界が発生する。電極１，３がプラスのと
き，電極２，４はマイナスであり，前者がマイナスのと
き，後者はプラスとなる。このような条件に加えて電極
１，２，３，４の凹凸形状が垂直，水平に１８０度ずれ
て形成されていることから，例えば，電極１，３がプラ
ス，電極２，４がマイナスのとき，中心軸上に軸方向の
電界が生じることになる。電極１，２，３，４の電圧極
性が逆になったときは，この電界の方向も逆になる。い
ま，中心軸に沿って四重極電極の中に入射されたイオン
が常に左右方向への加速電界を受けるような速度及び位
相をもつと，電極１，２，３，４の凹凸形状の部分を通
過する毎に加速され，単調にエネルギーが増加する。他
方，最初に減速を受けるような位相で入ってきたイオン
も，次の加速電界のときに後続のイオンの中に徐々にバ
ンチングされていき，後は単調に加速される。また，軸
に直交する平面に存在する強い高周波電界によって垂
直，水平方向には強い集束力が生じているため，非常に
高い透過率でイオンを加速させることができる。実際に
は，イオンの速度増加，バンチング状況に合わせて凹凸
形状の周期，電極間隔を徐々に変化させた電極を設計す
ることによって１００パーセント近い輸送効率を得るこ
とができる。2. Description of the Related Art As is well known, a high frequency quadrupole accelerator is designed to accelerate charged particles, which are injected between four vane electrodes (quadrupole electrodes) which generate a high frequency electric field, by the high frequency electric field. It is a structured accelerator. The basic configuration and operation of this radio frequency quadrupole accelerator (hereinafter referred to as RFQ accelerator) will be described below. In the RFQ accelerator shown in FIG. 8, electrodes 1, 2, 3, 4 forming a quadrupole electrode are arranged in the central axis direction of a cylindrical metal casing 5, and each electrode 1, 2, 3, 4 is arranged. Are formed in a corrugated shape with the opposite surfaces facing each other,
The concavo-convex shapes are formed in the same phase on the electrodes facing each other, and the concavo-convex shapes are formed on the opposite phases in the electrodes adjacent to each other. In the quadrupole electrode formed in this way,
As shown in FIG. 9, the electrodes facing each other have the same phase,
When a high frequency voltage of opposite phase is applied to the electrodes adjacent to each other, a quadrupole electric field is generated near the central axis where the four electrodes 1, 2, 3, 4 face each other. When the electrodes 1 and 3 are positive, the electrodes 2 and 4 are negative, and when the former is negative, the latter is positive. In addition to these conditions, since the concavo-convex shapes of the electrodes 1, 2, 3, 4 are vertically and horizontally shifted by 180 degrees, for example, the electrodes 1, 3 are positive and the electrodes 2, 4 are negative. Then, an axial electric field is generated on the central axis. When the voltage polarities of the electrodes 1, 2, 3, 4 are reversed, the direction of this electric field is also reversed. Now, if the ions injected into the quadrupole electrode along the central axis have such a velocity and phase that they always receive an accelerating electric field in the left-right direction, the uneven parts of the electrodes 1, 2, 3, 4 The energy is increased monotonically as it passes through. On the other hand, the ions that first enter the phase that undergoes deceleration are gradually bunched into the subsequent ions at the time of the next acceleration electric field, and are then monotonically accelerated. In addition, since the strong high-frequency electric field existing in the plane orthogonal to the axis produces a strong focusing force in the vertical and horizontal directions, the ions can be accelerated with a very high transmittance. Actually, by designing electrodes in which the ion velocity is increased, the period of the uneven shape and the electrode spacing are gradually changed according to the bunching situation, a transport efficiency close to 100% can be obtained.

【０００３】しかしながら，上記ＲＦＱ加速装置を例え
ば半導体へのイオン注入に適用する場合を考えると，次
のような不具合が生じる。イオン注入プロセスでは，イ
オンビーム中の不純物濃度が少ないほどよい。ところ
が，ＲＦＱ加速装置の特性としてイオン源からの不純物
ビームもそのまま透過させてしまう問題がある。即ち，
ＲＦＱ加速装置では四重極電極の凹凸形状と電極電圧，
高周波周波数と同期のとれたイオンしか加速されない
が，イオン生成のための原料中に含まれる不純物やイオ
ン源を構成する部材からの不純物元素は，加速はされな
いものの高周波四重極電場に誘導されて，そのままＲＦ
Ｑ加速装置の出口まで輸送される。そこで，従来のイオ
ン注入装置では，上記ＲＦＱ加速装置に限らず加速部の
前あるいは後に質量分析用の磁石が配置され，不純物イ
オンを除去することがなされる。しかし，このような構
成を採用した場合，質量分析磁石のため装置全体が大型
化する問題が生じる。この問題を解決する試みとして質
量分析機能を備えたＲＦＱ加速装置が，特公平５−５８
２４０号公報に開示されている。上記質量分析機能を備
えたＲＦＱ加速装置は，図１０に示すように構成されて
いる。図１０に示すように，四重極電極１，２，３，４
は絶縁物４４を介して金属筐体５に取り付けられ，コイ
ル４１とコンデンサ４２とからなる外部共振器４０から
高周波電力と，この高周波電力に重畳させて直流電源４
３からの直流電圧が上記四重極電極１，２，３，４に供
給される。上記構成では，四重極電極１，２，３，４間
の加速軸と直角の方向に高周波四重極電場が生じて入射
されたイオンが加速されると共に，印加される直流電圧
により周知技術である四重極マスフィルタ（ＱＭＦ）と
同様の電場が生じるため，イオンの加速と質量分析とが
同時になされ，加速器からは不純物が除かれた所望のイ
オンが加速されて出力される。However, considering the case where the RFQ accelerator is applied to, for example, ion implantation into a semiconductor, the following problems occur. In the ion implantation process, the lower the impurity concentration in the ion beam, the better. However, as a characteristic of the RFQ accelerator, there is a problem that the impurity beam from the ion source is transmitted as it is. That is,
In the RFQ accelerator, the uneven shape of the quadrupole electrode and the electrode voltage,
Only ions synchronized with the high frequency are accelerated, but impurities contained in the raw material for ion generation and impurity elements from the members constituting the ion source are not accelerated but are induced by the high frequency quadrupole electric field. , RF as it is
Transported to the exit of the Q accelerator. Therefore, in the conventional ion implanter, not only the RFQ accelerator but also a magnet for mass spectrometry is arranged before or after the accelerator to remove the impurity ions. However, when such a configuration is adopted, the mass analysis magnet causes a problem that the entire apparatus becomes large. As an attempt to solve this problem, an RFQ accelerator equipped with a mass spectrometric function is disclosed in Japanese Patent Publication No. 5-58.
No. 240 publication. The RFQ accelerator having the above mass spectrometric function is configured as shown in FIG. As shown in FIG. 10, the quadrupole electrodes 1, 2, 3, 4
Is attached to the metal casing 5 via the insulator 44, and the high frequency power from the external resonator 40 including the coil 41 and the capacitor 42 is superimposed on the high frequency power.
The DC voltage from 3 is supplied to the quadrupole electrodes 1, 2, 3, and 4. In the above configuration, a high-frequency quadrupole electric field is generated in a direction perpendicular to the acceleration axis between the quadrupole electrodes 1, 2, 3, and 4 to accelerate the injected ions, and at the same time, a known DC voltage is applied by the applied DC voltage. Since an electric field similar to that of a quadrupole mass filter (QMF) is generated, acceleration of ions and mass analysis are simultaneously performed, and desired ions free of impurities are accelerated and output from the accelerator.

【０００４】[0004]

【発明が解決しようとする課題】しかしながら，上記従
来構成では外部共振器を通じて高周波電力が供給されて
いるため，外部共振器と加速器とを接続するケーブルに
無視できない浮遊インダクタンスや浮遊容量が生じ，ケ
ーブル部分での損失によりＱ値が低下する問題点があっ
た。又，重イオン加速に適した比較的低い周波数に共振
させようとすると，共振回路のコイル半径を大きくする
か，コンデンサの容量を上げる必要があるが，機構的に
大型化して機械的振動等の外部擾乱を受けやすく不安定
な装置となってしまう問題点があった。コイルのインダ
クタンスを増すべくコイル半径を小さくして巻数を増し
たり，コイル内部に磁性体を挿入することもできるが，
全磁場エネルギーは減少し，共振回路のＱ値の低下を招
いてしまう。そこで，本発明が目的とするところは，加
速空洞を形成する金属筐体の内部に共振回路を構成する
ことにより，Ｑ値の低下をまねくことなく質量分析機能
を有するＲＦＱ加速装置を提供することにある。However, since the high-frequency power is supplied through the external resonator in the above-mentioned conventional configuration, a stray inductance or stray capacitance that cannot be ignored is generated in the cable connecting the external resonator and the accelerator, There is a problem that the Q value is lowered due to the loss in the part. Also, when trying to resonate at a relatively low frequency suitable for heavy ion acceleration, it is necessary to increase the coil radius of the resonance circuit or increase the capacity of the capacitor, but mechanically upsizing causes mechanical vibration and the like. There is a problem in that the device is susceptible to external disturbance and becomes an unstable device. To increase the inductance of the coil, the radius of the coil can be reduced to increase the number of turns and a magnetic material can be inserted inside the coil.
The total magnetic field energy is reduced, leading to a reduction in the Q value of the resonant circuit. Therefore, an object of the present invention is to provide an RFQ accelerating device having a mass spectrometric function without causing a decrease in Q value by forming a resonance circuit inside a metal casing forming an acceleration cavity. It is in.

【０００５】[0005]

【課題を解決するための手段】上記目的を達成するため
に本発明が採用するは，相対向する２対の電極が十字方
向に配置され，該電極の対向面側に荷電粒子を加速させ
るための所定の波打ち形状が形成されてなる四重極電極
を金属筐体の中心軸方向に配設すると共に，上記金属筐
体内に共振回路を構成し，該共振回路を通じて上記四重
極電極に所定周波数の高周波電力を印加して上記四重極
電極間を通過させる荷電粒子を任意の速度に加速させる
高周波四重極加速装置において，上記四重極電極を相対
向する２対の電極間で絶縁し，該絶縁間の金属体近接配
置により上記共振回路の静電容量を形成すると共に，該
絶縁間に直流電圧を印加することにより，上記四重極電
極に直流電圧が重畳された上記高周波電力を印加するよ
うにしたことを特徴とする高周波四重極加速装置として
構成されている。In order to achieve the above object, the present invention employs that two pairs of electrodes facing each other are arranged in a cross direction to accelerate charged particles on the facing surface side of the electrodes. A quadrupole electrode having a predetermined corrugated shape is arranged in the central axis direction of the metal casing, and a resonance circuit is formed in the metal casing, and a predetermined quadrupole electrode is formed through the resonance circuit. In a high-frequency quadrupole accelerator for accelerating charged particles passing between the quadrupole electrodes at an arbitrary speed by applying high-frequency power of a frequency, the quadrupole electrodes are insulated between two pairs of electrodes facing each other. Then, the capacitance of the resonance circuit is formed by the disposition of the metal body between the insulations, and by applying a DC voltage between the insulations, the high-frequency power in which the DC voltage is superimposed on the quadrupole electrodes Is specially applied. It is configured as a high-frequency quadrupole accelerator to.

【０００６】[0006]

【作用】本発明によれば，相対向する２対の電極が十字
方向に配置されてなる四重極電極の上記相対向する２対
の電極間に金属体を近接配置することにより，加速空洞
を構成する金属筐体内に形成する共振回路の静電容量成
分を十分に大きくすることができ，重イオン等の荷電粒
子を加速する場合にも対応できる加速装置を構成するこ
とができる。金属筐体内に共振回路が形成されるので，
電気的，機械的に安定で，且つＱ値が低く高周波損失の
少ないＲＦＱ加速装置が構成される。同時に，上記相対
向する２対の電極間に高周波電力に重畳させて直流電圧
を印加し，高周波電圧と直流電圧との比を一定に保っ
て，それぞれの電圧を変化させることにより，四重極電
極は四重極マスフィルタの機能を発揮して，特定のイオ
ン種のみを加速内を透過させることができる。この透過
可能なイオン種をイオン注入等のプロセスに必要なイオ
ンと一致させることにより，不純物のない荷電粒子ビー
ムが出力できるＲＦＱ加速装置が構成される。According to the present invention, the accelerating cavity is formed by arranging the metal body close to each other between the two pairs of electrodes of the quadrupole electrode in which two pairs of electrodes facing each other are arranged in a cross direction. It is possible to sufficiently increase the capacitance component of the resonance circuit formed in the metal casing constituting the above, and to configure an accelerating device that can cope with the case of accelerating charged particles such as heavy ions. Since the resonance circuit is formed in the metal housing,
An RFQ accelerator that is electrically and mechanically stable, has a low Q value, and has little high frequency loss is configured. At the same time, a DC voltage is applied by superimposing it on the high-frequency power between the two pairs of electrodes facing each other, the ratio between the high-frequency voltage and the DC voltage is kept constant, and the respective voltages are changed, so that the quadrupole The electrode exerts the function of a quadrupole mass filter and allows only specific ion species to pass through in the acceleration. An RFQ accelerator capable of outputting a charged particle beam without impurities is configured by matching the permeable ion species with the ions required for a process such as ion implantation.

【０００７】[0007]

【実施例】以下，添付図面を参照して，本発明を具体化
した実施例につき説明し，本発明の理解に供する。尚，
以下の実施例は本発明を具体化した一例であって，本発
明の技術的範囲を限定するものではない。ここに，図１
は本発明の第１実施例に係るＲＦＱ加速装置の構成を断
面で示す模式図，図２は静電容量形成のための構成例を
示す部分断面図，図３は第１実施例に係る構成の等価回
路図である。図１において，第１実施例に係るＲＦＱ加
速装置１０は，イオン加速器として構成されており，共
振空洞を構成する筒状の金属筐体１６の中心軸方向に，
四重極電極が電極１１，１３と電極１２，１４とをそれ
ぞれ対向させて十字方向に配置すると共に，各電極１
１，１２，１３，１４は，それぞれ絶縁物１７を介して
上記金属筐体１６に支持されて構成されている。又，各
電極１１，１２，１３，１４には，それぞれ共振電極２
１，２２，２３，２４が固定されている。各共振電極１
１，１２，１３，１４のそれぞれが隣り合う近接端部は
互いに離隔絶縁させ，折り曲げ対向させて対向間に静電
容量を形成させている。この対向間の静電容量の形成
は，図２（ａ）（ｂ）に示すように形成することもで
き，対向面積によって静電容量の大きさを変化させるこ
とが可能となる。上記構成により金属筐体１６内に形成
される共振回路の等価回路は，図３に示すようになる。
同図において，２８は各電極１１，１２，１３，１４の
電極間静電容量，２７は上記各共振電極２１，２２，２
３，２４のそれぞれの端部を近接させて静電容量を形成
させた近接端部間静電容量である。上記各静電容量が形
成される間の導体は図示するようにインダクタンスとし
て，上記静電容量と共に共振回路が形成される。上記近
接端部間静電容量２７は，共振回路に直列に挿入される
ことになるため，共振回路の共振周波数を高くする方向
に働き，電極間静電容量２８に比べて小さいと，近接端
部に高電圧が発生し，加速電圧の低下や不要な放電現象
が生じる。従って，近接端部間静電容量２７は電極間静
電容量２８よりも十分に大きく，少なくとも１倍以上に
なるように近接端部の間隔及び対向面積を選択する。Embodiments of the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. still,
The following example is an example embodying the present invention and does not limit the technical scope of the present invention. Figure 1
1 is a schematic view showing in cross section the configuration of the RFQ accelerator according to the first embodiment of the present invention, FIG. 2 is a partial cross sectional view showing a configuration example for capacitance formation, and FIG. 3 is a configuration according to the first embodiment. 2 is an equivalent circuit diagram of FIG. In FIG. 1, an RFQ accelerator 10 according to the first embodiment is configured as an ion accelerator, and in the central axis direction of a cylindrical metal casing 16 that forms a resonance cavity,
The quadrupole electrodes are arranged in the cross direction with the electrodes 11 and 13 and the electrodes 12 and 14 facing each other, and each electrode 1
1, 12, 13, and 14 are configured to be supported by the metal casing 16 via an insulator 17, respectively. Further, each of the electrodes 11, 12, 13 and 14 has a resonance electrode 2
1, 22, 23 and 24 are fixed. Each resonance electrode 1
Proximity end portions adjacent to each of 1, 12, 13, and 14 are insulated and isolated from each other, and are bent and opposed to each other to form an electrostatic capacitance therebetween. The formation of the electrostatic capacitance between the facing portions can be formed as shown in FIGS. 2A and 2B, and the magnitude of the electrostatic capacitance can be changed depending on the facing area. An equivalent circuit of the resonance circuit formed in the metal casing 16 with the above configuration is as shown in FIG.
In the figure, 28 is the inter-electrode capacitance of the electrodes 11, 12, 13, 14 and 27 is the resonance electrodes 21, 22, 2 described above.
It is the capacitance between the adjacent ends where the respective ends of 3 and 24 are brought close to each other to form a capacitance. A resonance circuit is formed together with the above-mentioned capacitances as an inductance of the conductor while the above-mentioned capacitances are formed, as shown in the figure. Since the capacitance 27 between the adjacent ends is inserted in series with the resonance circuit, it works in the direction of increasing the resonance frequency of the resonance circuit, and if it is smaller than the capacitance 28 between the electrodes, it is close to the proximity end. A high voltage is generated in the area, and the acceleration voltage drops and unnecessary discharge occurs. Therefore, the capacitance 27 between the adjacent ends is sufficiently larger than the capacitance 28 between the electrodes, and the distance between the adjacent ends and the facing area are selected so as to be at least 1 time or more.

【０００８】上記のように構成されたＲＦＱ加速装置１
０に，図１に示すように相対向する電極１１，１３と１
２，１４との間に高周波電力１８と直流電圧１９とを重
畳して印加すると，各電極１１，１２，１３，１４間に
は四重極電場が発生し，先に説明したような各電極の波
打ち形状と相まって電極間に入射されるイオンビームを
加速する。同時に，高周波電圧に重畳された直流電圧が
印加されることにより，四重極電極は四重極マスフィル
タとして動作し，各電極１１，１２，１３，１４に囲ま
れた空間を通過するイオンは，一定の振幅を越えないで
安定な軌道を辿るものと，進行に伴って振幅が無限大に
発散するものとに分けられる。そこで，高周波電圧と直
流電圧との比を一定に保ち，適当な値に設定することに
より，イオン注入等のプロセスに必要なイオンのみが選
択加速される。次に，本発明の第２実施例について図４
を参照して説明する。図４は第２実施例に係るＲＦＱ加
速装置の構成を断面で示す模式図である。尚，上記第１
実施例構成と共通する要素には同一の符号を付して，そ
の説明は省略する。図４において，ＲＦＱ加速装置１５
は，第１実施例と同様に配設された共振電極２１，２
２，２３，２４の各端部が互いに隣り合う各近接端部間
を離隔絶縁し，その間に誘電体２０がそれぞれ配設され
て構成されている。この各近接端部間への誘電体２０の
挿入により，近接端部間静電容量を大きく形成すること
ができると共に，各共振電極２１，２２，２３，２４を
一体的に形成して機械的強度を向上させることができる
ので，装置の小型化を図ることができる。次いで，本発
明の第３実施例について説明する。ここに，図５は第３
実施例に係るＲＦＱ加速装置の構成を断面で示す模式図
である。図５において，第３実施例に係るＲＦＱ加速装
置４７は，金属筐体４８の中心軸方向に四重極電極を構
成する電極１１，１２，１３，１４が配設され，各電極
は上記金属筐体４８に絶縁物４９を介して支持されてい
る。上記各電極１１，１２，１３，１４には，それぞれ
共振電極５１，５２，５３，５４が取り付けられて，金
属筐体４８との間で静電容量を形成している。次いで，
本発明の第４実施例について説明する。ここに，図６は
第４実施例に係るＲＦＱ加速装置の構成を断面で示す模
式図，図７は第３実施例に係る共振電極の構成を示す部
分斜視図である。RFQ accelerator 1 configured as described above
0, electrodes 11 and 13 facing each other as shown in FIG.
When the high frequency power 18 and the DC voltage 19 are superposed and applied between the electrodes 2 and 14, a quadrupole electric field is generated between the electrodes 11, 12, 13 and 14, and each electrode as described above is generated. The ion beam incident between the electrodes is accelerated in combination with the corrugated shape. At the same time, by applying a DC voltage superimposed on the high frequency voltage, the quadrupole electrode acts as a quadrupole mass filter, and ions passing through the space surrounded by the electrodes 11, 12, 13, 14 are , It is divided into those that follow a stable trajectory without exceeding a certain amplitude and those that diverge infinitely with progress. Therefore, by keeping the ratio between the high frequency voltage and the DC voltage constant and setting it to an appropriate value, only the ions necessary for the process such as ion implantation are selectively accelerated. Next, a second embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. FIG. 4 is a schematic diagram showing in cross section the configuration of the RFQ accelerator according to the second embodiment. In addition, the first
The elements common to those of the embodiment configuration are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 4, the RFQ accelerator 15
Are resonant electrodes 21, 2 arranged in the same manner as in the first embodiment.
Each of the end portions 2, 23, and 24 isolates and insulates the adjacent end portions that are adjacent to each other, and the dielectric 20 is disposed between them. By inserting the dielectric 20 between the adjacent end portions, it is possible to form a large capacitance between the adjacent end portions, and at the same time, to form the resonant electrodes 21, 22, 23, 24 integrally and mechanically. Since the strength can be improved, the device can be downsized. Next, a third embodiment of the present invention will be described. Here, FIG. 5 shows the third
It is a schematic diagram which shows the structure of the RFQ accelerator which concerns on an Example in a cross section. In FIG. 5, an RFQ accelerator 47 according to the third embodiment is provided with electrodes 11, 12, 13, and 14 that constitute a quadrupole electrode in the central axis direction of a metal housing 48, and each electrode is made of the above metal. It is supported by the housing 48 via an insulator 49. Resonant electrodes 51, 52, 53, 54 are attached to the electrodes 11, 12, 13, 14 to form capacitance with the metal housing 48. Then,
A fourth embodiment of the present invention will be described. Here, FIG. 6 is a schematic view showing the structure of the RFQ accelerator according to the fourth embodiment in cross section, and FIG. 7 is a partial perspective view showing the structure of the resonance electrode according to the third embodiment.

【０００９】図６において，第４実施例に係るＲＦＱ加
速装置２５は，金属筐体２６の中心軸方向に四重極電極
を構成する電極３１，３２，３３，３４が配設されてい
る。相対向する電極３１，３３は第１の金属環３５に，
電極３２，３４は第２の金属環３６に，図７に示すよう
に交互に支持されると共に，金属環３５は第１の共振電
極２９，金属環３６は第２の共振電極３０に接合され，
第１の共振電極２９と第２の共振電極３０とは図示する
ように互いに相手側の二股形成間に電極が入り込んで重
なり合い，大きな静電容量を形成している。更に，第１
の共振電極２９は第３の共振電極３７に接合され，第２
の共振電極３０は第４の共振電極３８に接合され，第３
の共振電極３７と第４の共振電極３８とは，それぞれ絶
縁物３９を介して金属筐体２６に支持されている。又，
第３の金属電極３７と第４の共振電極３８との端部が近
接する位置には対向部分が形成され，静電容量成分を形
成すると共に，第３の金属電極３７と第４の共振電極３
８とはインダクタンス成分を形成している。上記構成に
より，金属筐体２６内には静電容量とインダクタンスと
が形成された共振回路が構成され，これらの値が所望の
高周波周波数に一致するようにして，高周波電力１８と
直流電圧１９とを上記共振回路を通じて四重極電極に供
給することにより，ＲＦＱ加速装置２５は四重極マスフ
ィルタとしての機能を発揮すると同時に，Ｑ値の高い加
速装置として動作し，所望のイオンのみを所望のエネル
ギーに加速することができる。In FIG. 6, an RFQ accelerator 25 according to the fourth embodiment is provided with electrodes 31, 32, 33 and 34 forming a quadrupole electrode in the central axis direction of a metal casing 26. The electrodes 31 and 33 facing each other are provided on the first metal ring 35,
The electrodes 32 and 34 are alternately supported by the second metal ring 36 as shown in FIG. 7, and the metal ring 35 is bonded to the first resonance electrode 29 and the metal ring 36 is bonded to the second resonance electrode 30. ，
As shown in the figure, the first resonance electrode 29 and the second resonance electrode 30 are overlapped with each other by interposing the electrodes between the opposite bifurcated formations to form a large capacitance. Furthermore, the first
The resonance electrode 29 of is connected to the third resonance electrode 37,
The resonance electrode 30 of the
The resonance electrode 37 and the fourth resonance electrode 38 are each supported by the metal casing 26 via an insulator 39. or,
A facing portion is formed at a position where the end portions of the third metal electrode 37 and the fourth resonance electrode 38 are close to each other to form a capacitance component, and the third metal electrode 37 and the fourth resonance electrode 38 are formed. Three
8 forms an inductance component. With the above-described configuration, a resonance circuit in which a capacitance and an inductance are formed is formed in the metal casing 26, and these values are made to match the desired high frequency, and the high frequency power 18 and the DC voltage 19 are generated. Are supplied to the quadrupole electrode through the resonance circuit, the RFQ accelerator 25 functions as a quadrupole mass filter, and at the same time, operates as a high Q factor accelerator to obtain only desired ions. Can be accelerated to energy.

【００１０】[0010]

【発明の効果】以上の説明の通り本発明によれば，相対
向する２対の電極が十字方向に配置されてなる四重極電
極の上記相対向する２対の電極間に金属体を近接配置す
ることにより，加速空洞を構成する金属筐体内に共振回
路を形成することができる。金属筐体内に共振回路が形
成されるので，電気的，機械的に安定で，且つＱ値が低
く高周波損失の少ないＲＦＱ加速装置が構成されると同
時に，上記相対向する２対の電極間に高周波電力に重畳
させて直流電圧を印加して，高周波電圧と直流電圧との
比を一定に保って，それぞれの電圧を変化させることに
より，四重極電極は四重極マスフィルタの機能を発揮し
て，特定のイオン種のみを加速内を透過させることがで
きる。この透過可能なイオン種をイオン注入等のプロセ
スに必要なイオンと一致させることにより，不純物のな
い荷電粒子ビームが出力できるＲＦＱ加速装置が構成さ
れる。As described above, according to the present invention, a metal body is placed between two pairs of electrodes of a quadrupole electrode, the pair of electrodes facing each other in a cross direction. By arranging them, the resonance circuit can be formed in the metal casing that constitutes the acceleration cavity. Since the resonance circuit is formed in the metal casing, an RFQ accelerator which is electrically and mechanically stable, has a low Q value and has a small high frequency loss, and at the same time, is formed between the two pairs of electrodes facing each other. The quadrupole electrode exerts the function of a quadrupole mass filter by applying a DC voltage by superimposing it on the high-frequency power, keeping the ratio between the high-frequency voltage and the DC voltage constant, and changing each voltage. Then, only a specific ion species can be transmitted through the acceleration. An RFQ accelerator capable of outputting a charged particle beam without impurities is configured by matching the permeable ion species with the ions required for a process such as ion implantation.

【図面の簡単な説明】[Brief description of drawings]

【図１】 本発明の第１実施例に係るＲＦＱ加速装置の
構成を断面で示す模式図。FIG. 1 is a schematic view showing a cross section of a configuration of an RFQ accelerator according to a first embodiment of the present invention.

【図２】 実施例に係る共振電極の近接端部の形状例を
示す部分断面図。FIG. 2 is a partial cross-sectional view showing a shape example of a proximal end portion of a resonance electrode according to an embodiment.

【図３】 第１実施例に係る構成の等価回路を示す回路
図。FIG. 3 is a circuit diagram showing an equivalent circuit of the configuration according to the first embodiment.

【図４】 本発明の第２実施例に係るＲＦＱ加速装置の
構成を断面で示す模式図。FIG. 4 is a schematic view showing a cross section of the configuration of an RFQ accelerator according to a second embodiment of the present invention.

【図５】 本発明の第３実施例に係るＲＦＱ加速装置の
構成を断面で示す模式図。FIG. 5 is a schematic view showing a cross section of the configuration of an RFQ accelerator according to a third embodiment of the present invention.

【図６】 本発明の第４実施例に係るＲＦＱ加速装置の
構成を断面で示す模式図。FIG. 6 is a schematic diagram showing a cross section of a configuration of an RFQ accelerator according to a fourth embodiment of the present invention.

【図７】 第３実施例に係る共振電極の構成を示す斜視
図。FIG. 7 is a perspective view showing the configuration of a resonance electrode according to a third embodiment.

【図８】 高周波四重極加速装置の基本構成を示す模式
図。FIG. 8 is a schematic diagram showing a basic configuration of a high frequency quadrupole accelerator.

【図９】 四重極電極の動作原理を説明する模式図。FIG. 9 is a schematic diagram illustrating the operating principle of a quadrupole electrode.

【図１０】 従来例構成に係る高周波四重極加速装置の
構成を示す回路図。FIG. 10 is a circuit diagram showing a configuration of a high-frequency quadrupole accelerator according to a conventional configuration.

【符号の説明】[Explanation of symbols]

１０，１５，２５，４７…高周波四重極加速装置 １１，１２，１３，１４，３１，３２，３３，３４…電
極 １６，２６…金属筐体 １７，３９…絶縁物 １８…高周波電力 １９…直流電圧 ２０…誘電体 ２１，２２，２３，２４，２９，３０，３７，３８，５
１，５２，５３，５４…共振電極（金属体） ２７…近接端部間静電容量 ２８…電極間静電容量10, 15, 25, 47 ... High-frequency quadrupole accelerator 11, 12, 13, 14, 31, 32, 33, 34 ... Electrode 16, 26 ... Metal housing 17, 39 ... Insulator 18 ... High-frequency power 19 ... DC voltage 20 ... Dielectrics 21, 22, 23, 24, 29, 30, 37, 38, 5
1, 52, 53, 54 ... Resonant electrode (metal body) 27 ... Electrostatic capacitance between adjacent ends 28 ... Electrostatic capacitance between electrodes

フロントページの続き (72)発明者 井上 浩司 神戸市西区高塚台１丁目５番５号 株式会 社神戸製鋼所神戸総合技術研究所内 (72)発明者 今中 博文 神戸市西区高塚台１丁目５番５号 株式会 社神戸製鋼所神戸総合技術研究所内Front page continuation (72) Inventor Koji Inoue 1-5-5 Takatsukadai, Nishi-ku, Kobe City Kobe Steel Research Institute, Kobe Steel, Ltd. (72) Inventor Hirofumi Imanaka 1-5-5 Takatsukadai, Nishi-ku, Kobe City No. 5 Stock Company Kobe Steel Works, Kobe Research Institute

Claims (1)

Translated fromJapanese

【特許請求の範囲】[Claims]【請求項１】 相対向する２対の電極が十字方向に配置
され，該電極の対向面側に荷電粒子を加速させるための
所定の波打ち形状が形成されてなる四重極電極を金属筐
体の中心軸方向に配設すると共に，上記金属筐体内に共
振回路を構成し，該共振回路を通じて上記四重極電極に
所定周波数の高周波電力を印加して上記四重極電極間を
通過させる荷電粒子を任意の速度に加速させる高周波四
重極加速装置において，上記四重極電極を相対向する２
対の電極間で絶縁し，該絶縁間の金属体近接配置により
上記共振回路の静電容量を形成すると共に，該絶縁間に
直流電圧を印加することにより，上記四重極電極に直流
電圧が重畳された上記高周波電力を印加するようにした
ことを特徴とする高周波四重極加速装置。1. A metal casing having a quadrupole electrode in which two pairs of electrodes facing each other are arranged in a cross direction, and a predetermined corrugated shape for accelerating charged particles is formed on the facing surface side of the electrodes. And a resonance circuit is formed in the metal casing, and high-frequency power of a predetermined frequency is applied to the quadrupole electrodes through the resonance circuit so that the quadrupole electrodes pass through the charging circuit. In a high frequency quadrupole accelerator for accelerating particles to an arbitrary velocity, the quadrupole electrodes are opposed to each other 2
By insulating between the pair of electrodes and forming a capacitance of the resonance circuit by disposing a metal body close to the insulation, a DC voltage is applied between the insulations, so that a DC voltage is applied to the quadrupole electrodes. A high-frequency quadrupole accelerator characterized in that the superimposed high-frequency power is applied.