JP2010232129A - Charged particle beam device - Google Patents

Charged particle beam device Download PDF

Info

Publication number
JP2010232129A
JP2010232129A JP2009081076A JP2009081076A JP2010232129A JP 2010232129 A JP2010232129 A JP 2010232129A JP 2009081076 A JP2009081076 A JP 2009081076A JP 2009081076 A JP2009081076 A JP 2009081076A JP 2010232129 A JP2010232129 A JP 2010232129A
Authority
JP
Japan
Prior art keywords
charged particle
discharge
voltage
acceleration voltage
source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP2009081076A
Other languages
Japanese (ja)
Inventor
Kyoji Saito
藤 教 司 斎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jeol Ltd
Original Assignee
Jeol Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jeol Ltd filed Critical Jeol Ltd
Priority to JP2009081076A priority Critical patent/JP2010232129A/en
Publication of JP2010232129A publication Critical patent/JP2010232129A/en
Withdrawn legal-status Critical Current

Links

Images

Landscapes

  • Electron Sources, Ion Sources (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charged particle beam device capable of accurately detecting abnormal discharge of a charged particle source. <P>SOLUTION: The charged particle beam device is provided with a charged particle source 12, an accelerating voltage source 3 impressing accelerating voltage on the charged particle source 12, a transformer 30 having a gap G at a core C and a primary-side winding connected between the accelerating voltage source 3 and the charged particle source 12, a primary-side current detecting circuit detecting a current flowing in the primary-side winding N1 based on a current flowing in, or a voltage generated at, a secondary-side winding N2 of the transformer, and a discharge detecting circuit detecting discharge based on an output of the primary-side current detecting circuit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は荷電粒子線装置に使用される放電検出回路に関する。 The present invention relates to a discharge detection circuit used in a charged particle beam apparatus.

荷電粒子線装置は荷電粒子を熱電子放出させたり、電界放出させたりすることにより発生させ、その発生した荷電粒子を加速させ、被照射物に照射する。このような荷電粒子線装置は、電子顕微鏡、X線管、電子ビーム加熱装置、電子ビーム露光装置等多数あり、微少領域の観察、分析、加工、加熱、X線発生装置など幅広い分野で使われている。   The charged particle beam device generates charged particles by causing thermionic emission or electric field emission, accelerates the generated charged particles, and irradiates an object to be irradiated. There are many such charged particle beam devices such as electron microscopes, X-ray tubes, electron beam heating devices, electron beam exposure devices, etc., and they are used in a wide range of fields such as observation, analysis, processing, heating, and X-ray generation devices in minute areas. ing.

このような荷電粒子線装置の一つである電子線照射装置の構成例を図1に示す。   A configuration example of an electron beam irradiation apparatus which is one of such charged particle beam apparatuses is shown in FIG.

図中1は熱電子を放出するフィラメントであり、2はフィラメント1に電流を流すフィラメント電源である。3は加速電圧電源でフィラメント1に加速電圧を印加する。50は荷電粒子線が照射される試料であり、試料50はグランドに電気的に接続されている。5はフィラメント1から放出される電子線である。   In the figure, reference numeral 1 denotes a filament that emits thermoelectrons, and reference numeral 2 denotes a filament power source that supplies current to the filament 1. Reference numeral 3 denotes an acceleration voltage power source for applying an acceleration voltage to the filament 1. Reference numeral 50 denotes a sample irradiated with a charged particle beam, and the sample 50 is electrically connected to the ground. Reference numeral 5 denotes an electron beam emitted from the filament 1.

フィラメント1から試料50まで、電子線の通る部分は真空チャンバ6の中にあり、真空チャンバ6は真空ポンプ(図示せず)により真空に引かれる。真空チャンバ6は電気的にグランドに接続されている。加速電圧上の電位にあるフィラメント1は絶縁碍子7で絶縁しチャンバ6に保持されている。また、絶縁碍子7にはウエネルト8がフィラメント1を取り囲むように取り付けられている。ウエネルト8とフィラメント1間にウエネルト電源4が接続してあり、フィラメント1に対し負(マイナス)の電位を印加している。10はカソードであり、ウエネルト8を取り囲むように取り付けられている。また、カソードは電気的にグランドに繋がっている。   The portion through which the electron beam passes from the filament 1 to the sample 50 is in the vacuum chamber 6, and the vacuum chamber 6 is evacuated by a vacuum pump (not shown). The vacuum chamber 6 is electrically connected to the ground. The filament 1 at the potential on the acceleration voltage is insulated by an insulator 7 and held in a chamber 6. A Wehnelt 8 is attached to the insulator 7 so as to surround the filament 1. A Wehnelt power supply 4 is connected between the Wehnelt 8 and the filament 1, and a negative (minus) potential is applied to the filament 1. A cathode 10 is attached so as to surround the Wehnelt 8. The cathode is electrically connected to the ground.

フィラメント1の先端から試料50へ電子線5が照射されるようにウエネルト8にはウエネルト穴9が開けられ、カソード10にはカソード穴11が開けられている。フィラメント1、ウエネルト8、カソード10で荷電粒子線源である電子銃12を構成している。   A Wehnelt hole 9 is formed in the Wehnelt 8 and a cathode hole 11 is formed in the cathode 10 so that the electron beam 5 is irradiated from the tip of the filament 1 to the sample 50. The filament 1, Wehnelt 8, and cathode 10 constitute an electron gun 12 that is a charged particle beam source.

20は加速電圧を2本の抵抗で分圧する分圧器である。21は比較器であり、加速電圧を分圧器20で分圧した電圧を、比較基準電圧源22が出力する基準電圧Vrefと比較し放電検出信号を出力する。23は保護回路で比較器21からの放電検出信号を受けて動作する。   A voltage divider 20 divides the acceleration voltage with two resistors. Reference numeral 21 denotes a comparator which compares the voltage obtained by dividing the acceleration voltage by the voltage divider 20 with the reference voltage Vref output from the comparison reference voltage source 22 and outputs a discharge detection signal. Reference numeral 23 denotes a protection circuit which operates upon receiving a discharge detection signal from the comparator 21.

このような装置において、電流をフィラメント電源2からフィラメント1に流しフィラメント1を加熱する。加熱されたフィラメント1からは熱電子が放出される。しかし、フィラメント1の周囲にウエネルト8がウエネルト電源4によりフィラメント1に対し負(マイナス)の電位に印加されている。そのため、負の電荷を持つ熱電子はウエネルト8に対し反発する。そして熱電子はウエネルト8に開けられた穴9を通りカソード10に引き寄せられて加速し、電子線となってカソード10の穴11を通り試料4に照射される。   In such an apparatus, a current is passed from the filament power source 2 to the filament 1 to heat the filament 1. Thermoelectrons are emitted from the heated filament 1. However, a Wehnelt 8 is applied around the filament 1 to a negative (minus) potential with respect to the filament 1 by a Wehnelt power source 4. Therefore, thermoelectrons having a negative charge repel the Wehnelt 8. Then, the thermoelectrons are attracted to the cathode 10 through the hole 9 formed in the Wehnelt 8 and accelerated, and become an electron beam and irradiated to the sample 4 through the hole 11 of the cathode 10.

電子を加速する加速電圧は低くても1kV程度で、時には1000kVに及ぶ事もあり、加速電圧とグランド間で不要な放電がしばしば発生する。これを不用放電と呼ぶ。不要放電が起こると加速電圧源3の出力はグランドに短絡されるのと同じ状態となり急激な放電電流が流れる。連続的な不要放電は加速電圧電源3の破壊を引き起こす事もある。また、荷電粒子線装置を電子ビーム蒸着装置として使った場合は不要放電による加速電圧の変動で均一な蒸着膜が出来ず不良品の原因になったりすることもある。この不用放電を検出し、不用放電が発生しても加速電圧が安定するように制御する方法、また不要放電が起きると加速電圧印加を停止し、保護する方法などが考案されている。   The acceleration voltage for accelerating electrons is at least about 1 kV, sometimes up to 1000 kV, and unnecessary discharge often occurs between the acceleration voltage and the ground. This is called unnecessary discharge. When unnecessary discharge occurs, the output of the acceleration voltage source 3 is in the same state as short-circuited to the ground, and a rapid discharge current flows. Continuous unnecessary discharge may cause destruction of the acceleration voltage power supply 3. In addition, when the charged particle beam apparatus is used as an electron beam vapor deposition apparatus, a uniform vapor deposition film cannot be formed due to fluctuations in acceleration voltage due to unnecessary discharge, which may cause defective products. A method of detecting the unnecessary discharge and controlling the acceleration voltage to be stable even if the unnecessary discharge occurs, and a method of stopping and protecting the application of the acceleration voltage when an unnecessary discharge occurs have been devised.

不用放電の検出は、加速電圧が不用放電により変化するのを検出するのが一般的である。しかし加速電圧は高電圧のため直接加速電圧の変化を検出するのは困難である。そのため2本の抵抗で構成される分圧抵抗20を加速電圧電源3の出力とグランド間に接続し、加速電圧を10ボルト程度に分圧する。不用放電によって加速電圧がドロップすると分圧電圧もドロップする。予め比較基準電圧源22設定し基準電圧Vrefを決定しておき、分圧電圧が、その基準電圧Vrefよりもドロップした場合不用放電と判断し比較器21は不要放電検出信号を出力する。比較器21が不要放電と判定し、出力した信号を保護回路23が受け加速電圧を下げたり加速電圧印加を中止したりする。   In general, the unnecessary discharge is detected by detecting that the acceleration voltage changes due to the unnecessary discharge. However, since the acceleration voltage is high, it is difficult to detect a change in the acceleration voltage directly. Therefore, a voltage dividing resistor 20 composed of two resistors is connected between the output of the acceleration voltage power supply 3 and the ground, and the acceleration voltage is divided to about 10 volts. When the acceleration voltage drops due to unnecessary discharge, the divided voltage also drops. The comparison reference voltage source 22 is set in advance to determine the reference voltage Vref. If the divided voltage drops below the reference voltage Vref, it is determined that the discharge is unnecessary, and the comparator 21 outputs an unnecessary discharge detection signal. The comparator 21 determines that the discharge is unnecessary, and the protection circuit 23 receives the output signal to lower the acceleration voltage or stop application of the acceleration voltage.

特開平8−22797号公報JP-A-8-22797

さて、図1に示すように、加速電圧とグランド間に2本の抵抗を直列接続して構成した分圧抵抗20が加速電圧とグランド間に接続されている。   As shown in FIG. 1, a voltage dividing resistor 20 configured by connecting two resistors in series between the acceleration voltage and the ground is connected between the acceleration voltage and the ground.

電子線発生装置の場合、電子線を加速するには加速電圧電源3はマイナスの電圧を出力する。そのため、分圧器20にはグランドから加速電圧電源3に向かって電流が流れる。加速電圧電源3は高電圧電源であり、負荷電流を多く取れる様にするには、電源が大型になるだけでなく非常にコストもかかる。そのため、なるべく電流を分圧器20に流さないようにするために分圧器に数百MΩなどの大きな抵抗値のものを用いる。   In the case of an electron beam generator, the acceleration voltage power supply 3 outputs a negative voltage to accelerate the electron beam. Therefore, a current flows through the voltage divider 20 from the ground toward the acceleration voltage power supply 3. The acceleration voltage power supply 3 is a high voltage power supply, and in order to obtain a large load current, not only the power supply becomes large but also very expensive. Therefore, in order to prevent the current from flowing through the voltage divider 20 as much as possible, a voltage divider having a large resistance value such as several hundred MΩ is used.

しかし、分圧抵抗20に流す電流を減らすと比較器21の入力端子に流れ込む電流も無視できなくなる。そのため、抵抗による分圧比だけで加速電圧の分圧電圧が得られなくなり、正確に不用放電を判定できなくなる。   However, if the current flowing through the voltage dividing resistor 20 is reduced, the current flowing into the input terminal of the comparator 21 cannot be ignored. For this reason, the divided voltage of the acceleration voltage cannot be obtained only by the voltage dividing ratio by the resistance, and the unnecessary discharge cannot be accurately determined.

更に、加速電圧を変えて使用すると分圧器の電圧も変化するため、比較器21判定基準となる比較基準電圧源22を設定しなおし基準電圧Vrefを加速電圧に合わせその都度変更する必要があった。   Further, when the acceleration voltage is changed, the voltage of the voltage divider also changes. Therefore, it is necessary to reset the comparison reference voltage source 22 as a reference for the comparator 21 and change the reference voltage Vref to the acceleration voltage each time. .

その他にも、分圧抵抗20が放電しても同じ不要放電であるので、分圧抵抗20が不要放電を起さないように絶縁油中に入れる、もしくはシリコン等で固体モールドするなどの放電防止策が必要である。それにより小型化できないだけでなくコストも上がる。   In addition, even if the voltage dividing resistor 20 is discharged, the same unnecessary discharge is generated, so that the voltage dividing resistor 20 is placed in an insulating oil so as not to cause unnecessary discharge or is solid-molded with silicon or the like. A measure is needed. This not only reduces the size but also increases the cost.

また、図2に1つの加速電圧電源3で複数の荷電粒子源12,12bを使う場合の例を示す。この場合どの電子銃7,7bのどちらで不要放電が発生しても加速電圧は変動するため、不要放電を起した電子銃の断定はできなかった。   FIG. 2 shows an example in which a plurality of charged particle sources 12 and 12b are used with one acceleration voltage power source 3. In this case, the acceleration voltage fluctuates regardless of which of the electron guns 7 and 7b generates an unnecessary discharge. Therefore, the electron gun that caused the unnecessary discharge could not be determined.

荷電粒子源と、該荷電粒子源に加速電圧を印加する加速電圧源と、コアにギャップを有し前記加速電圧源と荷電粒子源間に1次側巻き線が接続されたトランスと、該トランスの2次側巻き線に流れる電流又は発生する電圧に基づいて1次側巻き線に流れる電流を検出する1次電流検出回路と、該1次電流検出回路の出力に基づいて放電を検出する放電検出回路を備えたことを特徴とする荷電粒子線装置。   A charged particle source, an acceleration voltage source for applying an acceleration voltage to the charged particle source, a transformer having a gap in the core and having a primary winding connected between the acceleration voltage source and the charged particle source, and the transformer A primary current detection circuit for detecting a current flowing in the primary winding based on a current flowing in the secondary winding or a generated voltage, and a discharge for detecting discharge based on the output of the primary current detection circuit A charged particle beam apparatus comprising a detection circuit.

本発明によれば、荷電粒子源の異常放電を正確に検出可能な荷電粒子線装置を提供することができる。   ADVANTAGE OF THE INVENTION According to this invention, the charged particle beam apparatus which can detect the abnormal discharge of a charged particle source correctly can be provided.

以下、図面を参照して本発明の実施するための最良の形態を説明する。図3に本発明による荷電粒子線装置の一概略例を示す。また、図1で使用した記号と同一の記号としたものは同一構成要素である。   The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 3 shows a schematic example of a charged particle beam apparatus according to the present invention. Moreover, what was made into the symbol same as the symbol used in FIG. 1 is the same component.

フィラメント1、フィラメント電源2、加速電圧電源3、試料50、電子線5、真空チャンバ6、絶縁碍子7、ウエネルト8、ウエネルト電源4、カソード10、ウエネルト穴9、カソード穴11は従来技術と同様である。30はカレントトランスである。カレントトランス30はギャップGがあるコアCに1次側巻き線N1と2次側巻き線N2を巻いた構造になっている。カレントトランス30の1次側には加速電圧電源3とフィラメント1間のケーブルが巻かれ、2次側巻き線の両端には検出抵抗31が取り付けられている。検出抵抗31の片側はグランドに接続され、逆端は比較器21に接続されている。比較器21は比較基準電圧源22の出力である基準電圧Vrefと検出抵抗31の電圧を比較するために接続されている。   Filament 1, filament power source 2, acceleration voltage power source 3, sample 50, electron beam 5, vacuum chamber 6, insulator 7, Wehnelt 8, Wehnelt power source 4, cathode 10, Wehnelt hole 9 and cathode hole 11 are the same as in the prior art. is there. Reference numeral 30 denotes a current transformer. The current transformer 30 has a structure in which a primary winding N1 and a secondary winding N2 are wound around a core C having a gap G. A cable between the acceleration voltage power source 3 and the filament 1 is wound around the primary side of the current transformer 30, and detection resistors 31 are attached to both ends of the secondary side winding. One side of the detection resistor 31 is connected to the ground, and the opposite end is connected to the comparator 21. The comparator 21 is connected to compare the reference voltage Vref, which is the output of the comparison reference voltage source 22, with the voltage of the detection resistor 31.

このような装置において従来技術と同様にフィラメント1に電流を流して加熱し、加速電圧をフィラメント1に印加して電子線5を試料50に照射させる。   In such an apparatus, a current is passed through the filament 1 to heat it as in the prior art, and an acceleration voltage is applied to the filament 1 to irradiate the sample 50 with the electron beam 5.

電子線5を試料50に照射中に加速電圧とグランド間で不要放電が起こるとグランドから加速電圧電源3に放電電流が流れる。カレントトランス30の1次側巻き線N1をフィラメント1と加速電源3間に接続する。すると、放電電流はグランドからカレントトランス30の1次側巻き線N1を経由して加速電源30に流れる。そしてカレントトランス30の2次側巻き線N2には1次側巻き線に流れる一次電流に比例した電流が発生する。カレントトランス30の2次側巻き線の両端に検出抵抗31を接続しておくと、検出抵抗31に2次側巻き線発生した電流が流れ、検出抵抗31の両端は電圧降下により電圧Vsが発生する。検出抵抗31の両端の電圧は不要放電が無ければ0Vであり、放電が起これば電圧Vsをする発生するため1次電流検出回路として動作する。これにより検出抵抗31の両端に発生する電圧Vsを観測すれば不要放電を検出できる。   If an unnecessary discharge occurs between the acceleration voltage and the ground while the sample 50 is irradiated with the electron beam 5, a discharge current flows from the ground to the acceleration voltage power source 3. The primary winding N1 of the current transformer 30 is connected between the filament 1 and the acceleration power source 3. Then, the discharge current flows from the ground to the acceleration power supply 30 via the primary winding N1 of the current transformer 30. A current proportional to the primary current flowing in the primary winding is generated in the secondary winding N2 of the current transformer 30. If the detection resistor 31 is connected to both ends of the secondary winding of the current transformer 30, the current generated by the secondary winding flows in the detection resistor 31, and the voltage Vs is generated at both ends of the detection resistor 31 due to a voltage drop. To do. The voltage at both ends of the detection resistor 31 is 0 V when there is no unnecessary discharge, and the voltage Vs is generated when discharge occurs, so that it operates as a primary current detection circuit. Thus, unnecessary discharge can be detected by observing the voltage Vs generated across the detection resistor 31.

検出抵抗31の両端に発生した電圧Vsは比較器21に入力され、比較基準電圧源22の出力である基準電圧Vrefと比較する。そして比較器21が不要放電と判定した場合は比較器21から不要放電検出信号を出力する。比較器21が出力した不要放電検出信号は保護回路23に入力され、不要放電検出信号を受けた保護回路23は加速電圧を下げ加速電圧印加を中止する。   The voltage Vs generated at both ends of the detection resistor 31 is input to the comparator 21 and compared with the reference voltage Vref that is the output of the comparison reference voltage source 22. If the comparator 21 determines that the discharge is unnecessary, the comparator 21 outputs an unnecessary discharge detection signal. The unnecessary discharge detection signal output from the comparator 21 is input to the protection circuit 23. Upon receiving the unnecessary discharge detection signal, the protection circuit 23 lowers the acceleration voltage and stops applying the acceleration voltage.

しかし、微少な放電では装置の保護回路を動作は行わず、大放電時のみ保護を行いたい場合も多い。その場合は比較器21に接続されている比較基準電圧源22の設定を変え基準電圧Vrefをあげ、放電電流の大きい放電のみを検出すればよい。   However, there are many cases where it is desired to protect only during a large discharge without operating the protection circuit of the device with a slight discharge. In that case, it is only necessary to change the setting of the comparison reference voltage source 22 connected to the comparator 21 to increase the reference voltage Vref and detect only the discharge with a large discharge current.

さて、図4にカレントトランス30を示す。カレントトランス30はフェライトなどの強磁性体のコアに1次側巻き線N1と2次側巻き線N2を巻いて作られている。   FIG. 4 shows the current transformer 30. The current transformer 30 is formed by winding a primary winding N1 and a secondary winding N2 around a ferromagnetic core such as ferrite.

図5にカレントトランス30の外部磁束(1次巻き線N1により発生する磁束)に対するコアCの磁束密度のグラフを示す。   FIG. 5 shows a graph of the magnetic flux density of the core C with respect to the external magnetic flux of the current transformer 30 (the magnetic flux generated by the primary winding N1).

カレントトランス31の1次側巻き線N1に電流Iを流し、強磁性体でできたコアCに1次巻き線N1から磁界を加えて行く。外部磁界Hがゼロの場合は磁束密度Bもゼロであり、外部磁界Hの強さを増やしていくと比例してコアCの磁束密度Bも増え飽和磁束密度Bmに達すると外部磁界の強さHをそれ以上げても磁束密度Bは増えない。これはコアCが飽和したからである。   A current I is passed through the primary winding N1 of the current transformer 31, and a magnetic field is applied from the primary winding N1 to the core C made of a ferromagnetic material. When the external magnetic field H is zero, the magnetic flux density B is also zero. When the strength of the external magnetic field H is increased, the magnetic flux density B of the core C increases in proportion to the saturation magnetic flux density Bm. Increasing H beyond that does not increase the magnetic flux density B. This is because the core C is saturated.

カレントトランス31の1次側巻き線N1から2次側巻き線N2へのエネルギーの伝達は、1次側巻き線N1によって発生した磁界がコアCの磁束密度Bを変化させ、その磁束密度Bの変化によって2次側巻き線N2に電流を発生させる。コアCが飽和した場合、磁束密度Bの変化は無くなるため2次側巻き線N2にエネルギー伝達はされなくなってしまう。   In the transmission of energy from the primary winding N1 of the current transformer 31 to the secondary winding N2, the magnetic field generated by the primary winding N1 changes the magnetic flux density B of the core C. The change causes a current to be generated in the secondary winding N2. When the core C is saturated, the magnetic flux density B does not change, and energy is not transmitted to the secondary winding N2.

コアCに加える磁界の強さは1次側のターン数と流す電流によって決まる。加速電圧の放電は、高電圧である加速電源3をグランドに短絡した事とほぼ等しく、その放電電流は大変大きい。1次側巻き線のターン数を減らしても放電電流が大きくコアが飽和してしまう場合がある。コアを飽和させないためにはコアの断面積を増やす、もしくはコアの透磁率を低くする事が必要となる。   The strength of the magnetic field applied to the core C is determined by the number of turns on the primary side and the current that flows. The discharge of the acceleration voltage is almost equivalent to the short-circuit of the acceleration power supply 3 which is a high voltage, and the discharge current is very large. Even if the number of turns of the primary winding is reduced, the discharge current is large and the core may be saturated. In order not to saturate the core, it is necessary to increase the cross-sectional area of the core or lower the magnetic permeability of the core.

コアの断面積を増やし飽和を避けた場合は、コア自体を大きくすることになりカレントトランス30が大型になり現実的ではない。また、コアの透磁率を変えるにはコアの材質を変えればよいが最適な透磁率の材質を選択するのは困難である。   When the cross-sectional area of the core is increased and saturation is avoided, the core itself is enlarged and the current transformer 30 becomes large, which is not realistic. Further, in order to change the magnetic permeability of the core, the material of the core may be changed, but it is difficult to select a material having the optimum magnetic permeability.

そこで、カレントトランス30のコアにギャップを設ける。図4(b)にカレントトランス30のコアCにギャップGを設けた状態を示す。   Therefore, a gap is provided in the core of the current transformer 30. FIG. 4B shows a state where a gap G is provided in the core C of the current transformer 30.

図5に戻り、カレントトランス30のコアにギャップがある場合の外部磁束に対する磁束密度の変化を説明する。   Returning to FIG. 5, the change in the magnetic flux density with respect to the external magnetic flux when there is a gap in the core of the current transformer 30 will be described.

外部磁界Hがゼロの場合は磁束密度Bもゼロであり、外部磁界Hの強さを増やしていくと比例して磁束密度Bも増える。そして、飽和磁束密度Bmに達すると外部磁界の強さHをそれ以上げても磁束密度Bは増えない。しかし、コアギャップ無しの場合は外部磁界の強さがA点で飽和磁束密度Bmに達するのに対し、コアギャップがある場合は外部磁界の強さがA点より大きいB点で飽和する。ここで、コアのギャップGを大きくする(広げる)と飽和磁束密度Bmに達する外部磁界の強さはより大きくなり、コアのギャップGを小さくする(狭める)と飽和磁束密度Bmに達する外部磁界の強さはA点に近づく。これは、カレントトランス31のコアCの透磁率を変えた事と同じである。さらにカレントトランス31のコアCのギャップを調整する事により最適な透磁率を得る事ができる。   When the external magnetic field H is zero, the magnetic flux density B is also zero. When the strength of the external magnetic field H is increased, the magnetic flux density B increases in proportion. When the saturation magnetic flux density Bm is reached, the magnetic flux density B does not increase even if the external magnetic field strength H is increased further. However, when there is no core gap, the strength of the external magnetic field reaches the saturation magnetic flux density Bm at point A, whereas when there is a core gap, the strength of the external magnetic field saturates at point B greater than point A. Here, when the core gap G is increased (expanded), the strength of the external magnetic field reaching the saturation magnetic flux density Bm is increased, and when the core gap G is decreased (decreased), the external magnetic field reaching the saturation magnetic flux density Bm is increased. The strength approaches point A. This is the same as changing the magnetic permeability of the core C of the current transformer 31. Furthermore, the optimum magnetic permeability can be obtained by adjusting the gap of the core C of the current transformer 31.

このようにコアCの透磁率を最適にしたため、カレントトランス31のコアCを小型化してもカレントトランス31のコアCは飽和せずに正確に放電検出ができる。   Since the magnetic permeability of the core C is optimized as described above, even if the core C of the current transformer 31 is downsized, the core C of the current transformer 31 is not saturated and discharge can be detected accurately.

また、加速電圧の変化を検出しているのではなく、放電電流を検出しているため加速電圧を変化させても比較器21が参照する比較基準電圧Vrefを比較基準電源22で設定しなおす必要が無くなる。   Further, since the change in the acceleration voltage is not detected but the discharge current is detected, it is necessary to reset the comparison reference voltage Vref referred to by the comparator 21 by the comparison reference power source 22 even if the acceleration voltage is changed. Disappears.

その他にも高圧部分は加速電源3とフィラメント1間の絶縁ケーブルをコアに巻く(1ターンの場合はコアに通す)だけのため、検出抵抗31やカレントトランス30を絶縁油中に浸す、もしくは固体モールド等の特別な絶縁は必要が無い。   In addition, the high-voltage part is simply wound around the insulation cable between the accelerating power source 3 and the filament 1 (passing through the core in the case of one turn), so that the detection resistor 31 and the current transformer 30 are immersed in insulation oil or solid. There is no need for special insulation such as a mold.

次に図6に1個の加速電圧電源3を複数の電子銃に接続し使用する場合の例を示す。図3の構成で構成する電子線照射装置を、加速電圧電源3以外全て2式構成している。これにより高価な加速電圧電源3を2つの荷電粒子銃で共用してコストを抑えている。   Next, FIG. 6 shows an example in which one acceleration voltage power source 3 is connected to a plurality of electron guns. The electron beam irradiation apparatus configured in the configuration of FIG. As a result, the expensive acceleration voltage power supply 3 is shared by the two charged particle guns, thereby reducing the cost.

ここで、第一電子銃12で不要放電があった場合の放電電流はカレントトランス30だけに流れ、カレントトランス30bには流れない。また、第二電子銃12bに不要放電があった場合はカレントトランス30bにだけ放電電流が流れ、カレントトランス30には放電電流が流れない。よって加速電圧電源を複数の電子銃に繋いで使えばどの電子銃で不要放電があったか認識する事ができる。   Here, when there is an unnecessary discharge in the first electron gun 12, the discharge current flows only to the current transformer 30 and does not flow to the current transformer 30b. Further, when there is an unnecessary discharge in the second electron gun 12b, a discharge current flows only in the current transformer 30b, and no discharge current flows in the current transformer 30. Therefore, if an accelerating voltage power source is connected to a plurality of electron guns, it can be recognized which electron gun has caused an unnecessary discharge.

尚、不要放電を検出して保護回路23を動作させ加速電圧を下げ加速電圧印加を中止して保護する場合について説明したが、比較回路21の出力にレコーダーを接続し、不要放電の頻度をモニタし、荷電粒子銃のメンテナンスの目安にしても良い。   In the above description, the protection circuit 23 is activated by detecting the unnecessary discharge, and the acceleration voltage is lowered to stop the application of the acceleration voltage for protection. However, a recorder is connected to the output of the comparison circuit 21 to monitor the frequency of unnecessary discharge. However, it may be used as a guide for maintenance of the charged particle gun.

尚、前記最良の形態は電子線照射装置に実施した場合について説明したが、イオン発生装置にも実施可能なことは言うまでもない。   In addition, although the said best form demonstrated the case where it implemented to the electron beam irradiation apparatus, it cannot be overemphasized that it can implement also to an ion generator.

従来の電子線照射装置の放電検出器の概略を示す。The outline of the discharge detector of the conventional electron beam irradiation apparatus is shown. 従来の加速電圧電源を複数の電子線照射装置で使用した場合の概略を示す。The outline at the time of using the conventional acceleration voltage power supply with several electron beam irradiation apparatus is shown. 本発明の電子線照射装置の放電検出器の概略を示す。The outline of the discharge detector of the electron beam irradiation apparatus of this invention is shown. カレントトランスの概略を示す。The outline of a current transformer is shown. 外部磁界の強さと磁束密度との関係を示すグラフである。It is a graph which shows the relationship between the intensity | strength of an external magnetic field, and magnetic flux density. 本発明の加速電圧電源を複数の電子線照射装置で使用した場合の概略を示す。The outline at the time of using the acceleration voltage power supply of this invention with a several electron beam irradiation apparatus is shown.

1,1b…フィラメント、2,2b…フィラメント電源、3,…加速電圧電源、4,4b…ウエネルト電源、5,5b…電子線、6,6b…真空チャンバ、7,7b…絶縁碍子、8,8b…ウエネルト、9,9b…ウエネルトの穴、10,10b…カソード、11,11b…カソードの穴、12,12b…電子銃、20…分圧抵抗、21,21b…比較器、22,22b…比較基準電圧源、23…保護回路、30,30b…カレントトランス、N1…カレントトランスの1次側巻き線、N2…カレントトランスの2次側巻き線、C…カレントトランスのコア、G…カレントトランスのコアのギャップ、検出電圧…Vs,Vs2、基準電圧…Vref,Vref2 DESCRIPTION OF SYMBOLS 1,1b ... Filament, 2, 2b ... Filament power supply, 3, ... Acceleration voltage power supply, 4, 4b ... Wehnelt power supply, 5, 5b ... Electron beam, 6, 6b ... Vacuum chamber, 7, 7b ... Insulator, 8, 8b: Wehnelt, 9, 9b: Wehnelt hole, 10, 10b ... Cathode, 11, 11b ... Cathode hole, 12, 12b ... Electron gun, 20 ... Voltage dividing resistor, 21, 21b ... Comparator, 22, 22b ... Comparative reference voltage source, 23 ... protection circuit, 30, 30b ... current transformer, N1 ... primary winding of current transformer, N2 ... secondary winding of current transformer, C ... core of current transformer, G ... current transformer Core gap, detection voltage ... Vs, Vs2, reference voltage ... Vref, Vref2

Claims (2)

荷電粒子源と、
該荷電粒子源に加速電圧を印加する加速電圧源と、
コアにギャップを有し前記加速電圧源と荷電粒子源間に1次側巻き線が接続されたトランスと、
該トランスの2次側巻き線に流れる電流又は発生する電圧に基づいて1次側巻き線に流れる電流を検出する1次電流検出回路と、
該1次電流検出回路の出力に基づいて放電を検出する放電検出回路を備えたことを特徴とする荷電粒子線装置。
A charged particle source;
An acceleration voltage source for applying an acceleration voltage to the charged particle source;
A transformer having a gap in the core and a primary winding connected between the acceleration voltage source and the charged particle source;
A primary current detection circuit for detecting a current flowing in the primary winding based on a current flowing in the secondary winding of the transformer or a generated voltage;
A charged particle beam apparatus comprising a discharge detection circuit that detects discharge based on an output of the primary current detection circuit.
荷電粒子源を複数有し、
1つの前記加速電圧源から複数個の荷電粒子源に加速電圧を印加するように構成されると共に、
前記各荷電粒子源と前記加速電圧源間に前記トランスを配置するようにしたことを特徴とする請求項1記載の荷電粒子線装置。
Have multiple charged particle sources,
Configured to apply an accelerating voltage from one accelerating voltage source to a plurality of charged particle sources;
The charged particle beam apparatus according to claim 1, wherein the transformer is arranged between the charged particle sources and the acceleration voltage source.
JP2009081076A 2009-03-30 2009-03-30 Charged particle beam device Withdrawn JP2010232129A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009081076A JP2010232129A (en) 2009-03-30 2009-03-30 Charged particle beam device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009081076A JP2010232129A (en) 2009-03-30 2009-03-30 Charged particle beam device

Publications (1)

Publication Number Publication Date
JP2010232129A true JP2010232129A (en) 2010-10-14

Family

ID=43047749

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009081076A Withdrawn JP2010232129A (en) 2009-03-30 2009-03-30 Charged particle beam device

Country Status (1)

Country Link
JP (1) JP2010232129A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015135847A (en) * 2014-01-16 2015-07-27 株式会社ニューフレアテクノロジー Electron beam lithography apparatus and electron beam lithography method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015135847A (en) * 2014-01-16 2015-07-27 株式会社ニューフレアテクノロジー Electron beam lithography apparatus and electron beam lithography method

Similar Documents

Publication Publication Date Title
JP6114981B2 (en) X-ray generator
US20170236683A1 (en) Particle beam apparatus and method for operating a particle beam apparatus
Cheng et al. Variation in time lags of vacuum surface flashover utilizing a periodically grooved dielectric
JP6779847B2 (en) Charged particle device, charged particle drawing device and charged particle beam control method
Kornilov et al. On the beam parameters of an electron gun with a plasma emitter
JP2010232129A (en) Charged particle beam device
Pikin et al. Structure and Design of the Electron Lens for RHIC
US20220415602A1 (en) Charged Particle Gun and Charged Particle Beam Device
Kittimanapun et al. Low Emittance Thermionic Electron Gun at SLRI
Zemskov et al. Instabilities of electrical properties of He-induced W “fuzz” within the pre-breakdown and breakdown regimes
RU2624916C2 (en) Method of electronic degassing microchannel plate
Li et al. Characterization of an electron gun for hollow electron beam collimation
US8507855B2 (en) Inductive modulation of focusing voltage in charged beam system
Gassner et al. RHIC electron lens test bench diagnostics
Kumar et al. A sub-nanosecond rise time intense electron beam source
Ovchinnikova et al. Optimization of an electron gun with an off-axis cathode position
Prakash et al. Characterization and testing of 30 kV, 60 kW electron optical column for melting applications
Satyanarayana et al. Experimental development of rod pinch diode radiographic source using modified Kali 1000 pulsed power system
Bryzgunov et al. Profile monitor for electron beam in the high-voltage electron cooling system of the COSY synchrotron
KR20110121004A (en) Power suppling apparatus for electron gus of scanning electron microscope
JP4545284B2 (en) High voltage power circuit
Shimabukuro et al. Suppression of damages on cathodes in the negative hydrogen ion source for the stable NBI system
Murata et al. Computer simulation of high brightness and high beam current electron gun for high-throughput electron beam lithography
JP4233103B2 (en) X-ray generator for X-ray inspection equipment
Bruker et al. Secondary Electron Measurements at the HIM Electron Cooler Test Set-Up

Legal Events

Date Code Title Description
A300 Application deemed to be withdrawn because no request for examination was validly filed

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20120605