JPH1167884A - Electrostatic attraction device and electron beam plotting apparatus using it - Google Patents
Electrostatic attraction device and electron beam plotting apparatus using itInfo
- Publication number
- JPH1167884A JPH1167884A JP22606197A JP22606197A JPH1167884A JP H1167884 A JPH1167884 A JP H1167884A JP 22606197 A JP22606197 A JP 22606197A JP 22606197 A JP22606197 A JP 22606197A JP H1167884 A JPH1167884 A JP H1167884A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- sample
- dielectric
- potential
- electrostatic
- 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.)
- Granted
Links
Landscapes
- Jigs For Machine Tools (AREA)
- Electron Beam Exposure (AREA)
- Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は試料の静電吸着装置
（静電チャック）及びそれを用いた電子線描画装置に係
り、特に電子線描画装置など、荷電粒子を試料に照射す
る装置内での使用に適した静電吸着装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample electrostatic chuck (electrostatic chuck) and an electron beam lithography apparatus using the same, and more particularly to an apparatus for irradiating a sample with charged particles, such as an electron beam lithography apparatus. The present invention relates to an electrostatic attraction device suitable for use in a device.
【０００２】[0002]
【従来の技術】電子線を利用した装置、例えば電子線描
画装置では、試料の描画時においてステージ機構により
加減速を伴う試料の移動が行われている。このため、試
料が所定の位置からずれないよう、試料保持を行う機能
が必要となる。さらに、成膜等のプロセスを経たウエハ
は、数十μｍもの凸形もしくは凹形に沿った形状になっ
ている。したがって、描画精度の面からこの反りを平坦
面に矯正する必要がある。2. Description of the Related Art In an apparatus using an electron beam, for example, an electron beam lithography apparatus, a stage mechanism moves a sample with acceleration and deceleration at the time of drawing the sample. For this reason, a function of holding the sample is required so that the sample does not shift from a predetermined position. Further, a wafer that has undergone a process such as film formation has a shape along a convex or concave shape of several tens of μm. Therefore, it is necessary to correct this warp to a flat surface in terms of drawing accuracy.
【０００３】この要求に対し、同じパターン露光を目的
とする縮小投影露光装置（ステッパ）では、大気圧下で
試料保持を行うため、真空吸着により試料の矯正が可能
である。しかし、電子線描画装置や測長・外観検査を目
的とした走査型電子顕微鏡（SEM）では、真空雰囲気内
で電子線を試料に照射するため、この真空吸着方式は採
用できない。[0003] In response to this requirement, a reduction projection exposure apparatus (stepper) for performing the same pattern exposure holds a sample under atmospheric pressure, so that the sample can be corrected by vacuum suction. However, an electron beam lithography apparatus or a scanning electron microscope (SEM) intended for length measurement and appearance inspection irradiates a sample with an electron beam in a vacuum atmosphere, so that this vacuum suction method cannot be adopted.
【０００４】そこで、静電力を利用した静電吸着装置を
用いて試料を保持している。この静電吸着装置は、試料
であるウエハ（半導体ウエハ）と試料ホルダ（試料保持
部材）を構成する誘電体の間に電圧を印加して電荷を発
生させることにより、静電力（静電吸着力）を確保して
いる。Therefore, a sample is held by using an electrostatic attraction device utilizing electrostatic force. This electrostatic attraction device applies electrostatic force (electrostatic attraction force) by applying a voltage between a sample wafer (semiconductor wafer) and a dielectric material constituting a sample holder (sample holding member) to generate electric charges. ).
【０００５】図３にこの種静電吸着装置の従来例を示
す。図３において、１は試料たるシリコンウエハ、２は
誘電体で構成された試料ホルダ、３は誘電体２に埋設し
た電極である。電極３はスイッチ１３を介して直流電源
４の（＋）側と接続される。電源４の（−）側は電流計
２０を介して接地されている。シリコンウエハ１は接地
電極たる導電性ピン７を介して接地電位に保たれてい
る。接地電極７は、ばね６及びベースパレット５（基
盤）を介して接地されており、また、上記ばね６の力で
ウエハ１に押しつけられている。なお、ウエハ１表面に
は、酸化膜（絶縁物）が形成されているので、上記の接
地電極７の接触部位では、ウエハ１との導電性を確保す
るためにこの絶縁物を除去する必要がある。絶縁物除去
としては、例えば特開昭６０−１１０１３３号公報に記
載されるように、予めウエハ上に一対の酸化膜破壊用の
電極をセットして、この電極を介して高電圧を放電さ
せ、その結果発生した熱によって酸化膜を破壊する手法
がある。FIG. 3 shows a conventional example of this kind of electrostatic attraction device. In FIG. 3, reference numeral 1 denotes a silicon wafer as a sample, 2 denotes a sample holder made of a dielectric, and 3 denotes an electrode embedded in the dielectric 2. The electrode 3 is connected to the (+) side of the DC power supply 4 via the switch 13. The (−) side of the power supply 4 is grounded via the ammeter 20. The silicon wafer 1 is maintained at a ground potential via conductive pins 7 serving as ground electrodes. The ground electrode 7 is grounded via a spring 6 and a base pallet 5 (base), and is pressed against the wafer 1 by the force of the spring 6. Since an oxide film (insulator) is formed on the surface of the wafer 1, it is necessary to remove the insulator at the contact portion of the ground electrode 7 in order to secure conductivity with the wafer 1. is there. For removing the insulator, for example, as described in JP-A-60-110133, a pair of oxide film breaking electrodes is set in advance on a wafer, and a high voltage is discharged through this electrode. There is a method of destroying an oxide film by heat generated as a result.
【０００６】上記構成において、スイッチ１３を閉じる
と、誘電体２側に設けた電極３と接地電極７との間に直
流電圧が印加され、ウエハ１・誘電体２間に静電力を発
生させ、この静電力によりウエハ１が誘電体２上に吸着
される。In the above configuration, when the switch 13 is closed, a DC voltage is applied between the electrode 3 provided on the dielectric 2 side and the ground electrode 7 to generate an electrostatic force between the wafer 1 and the dielectric 2, The wafer 1 is attracted onto the dielectric 2 by this electrostatic force.
【０００７】ところで、ウエハ１と接地電極７との間に
接触不良をきたした場合や、接地電極７に経時的な劣化
が生じて、ウエハと接地電極との導通が不十分である
と、充分な静電力が確保できず吸着不良が生じることが
ある。In the case where a contact failure occurs between the wafer 1 and the ground electrode 7 or when the ground electrode 7 deteriorates with time and the conduction between the wafer and the ground electrode is insufficient, sufficient contact is made. Insufficient electrostatic force may not be secured, and poor suction may occur.
【０００８】そこで、電子線照射の前に、試料が誘電体
に確実に吸着されているかを確認する必要がある。その
ために、従来は、図３に示すように、接地電極７がウエ
ハ１に接触した状態で静電吸着スイッチ１３が閉じてい
る時の誘電体２に流れる漏れ電流（充電電流、もしくは
定常電流）を電流計２０を用いて測定し、その大きさを
基準値（静電吸着力が正常に作動している時に誘電体に
流れる漏れ電流値）と比較することによって判定してい
た。あるいは、上記した特開昭６０−１１０１３３号に
記載されるように、ウエハと誘電体間に検査用の交流電
圧を印加してその静電容量を測定することによって、異
常検出をしていた（ウエハに接地不良が生じている場
合、ウエハと誘電体により形成される静電容量は小さく
なる）。Therefore, before the electron beam irradiation, it is necessary to confirm whether the sample is securely adsorbed on the dielectric. Therefore, conventionally, as shown in FIG. 3, a leakage current (charging current or steady current) flowing through the dielectric 2 when the electrostatic attraction switch 13 is closed with the ground electrode 7 in contact with the wafer 1. Was measured using an ammeter 20, and the magnitude was determined by comparing it with a reference value (a leakage current value flowing through the dielectric when the electrostatic attraction force was operating normally). Alternatively, as described in JP-A-60-110133, abnormality is detected by applying an inspection AC voltage between the wafer and the dielectric and measuring the capacitance thereof. When the grounding failure occurs on the wafer, the capacitance formed by the wafer and the dielectric decreases.)
【０００９】[0009]
（１）ところで、電子線描画装置においては、使用する
ウエハの種類が変わるとウエハの裏面状態が変化するこ
ともあり、特にウエハの裏面にも絶縁物が成膜されてい
る場合がある。(1) By the way, in the electron beam lithography apparatus, when the type of wafer to be used changes, the state of the back surface of the wafer may change. In particular, an insulator may be formed on the back surface of the wafer.
【００１０】この場合には、図３に示すような静電チャ
ックの検査法（誘電体２，ウエハ１，接地電極７を流れ
る漏れ電流からウエハの接地不良を検出する手法）によ
れば漏れ電流の絶対値が小さくなり、ノイズの影響で判
定が困難になる。In this case, according to the inspection method of the electrostatic chuck as shown in FIG. 3 (a method of detecting a ground failure of a wafer from a leakage current flowing through the dielectric 2, the wafer 1, and the ground electrode 7), Becomes small, and the determination becomes difficult due to the influence of noise.
【００１１】一方、ウエハと誘電体間に検査用の交流電
圧を印加してその静電容量を測定する手法の場合には、
ウエハ裏面に絶縁物が形成されていても静電容量を検出
することが可能であるが、たとえ検出できたとしても、
ウエハの種類によって静電容量が変化することになり、
判定レベルの設定が困難となる。On the other hand, in the case of a method of measuring the electrostatic capacitance by applying an inspection AC voltage between the wafer and the dielectric,
Capacitance can be detected even if an insulator is formed on the back surface of the wafer, but even if it can be detected,
The capacitance will change depending on the type of wafer,
It is difficult to set the judgment level.
【００１２】（２）また、ウエハと誘電体間に直流電圧
を印加してウエハを吸着する静電力を確保した場合であ
っても、接地電極のウエハへの接触度合いの低下や接地
電極に経時劣化が生じてウエハ・接地電極間の接触抵抗
が増大している場合もある。この場合、ウエハを流れる
漏れ電流によりウエハ上に表面電位が生じることにな
る。この電位はウエハ近傍の不要な電界を発生させるた
め、照射される電子線に対して、軌道を曲げてしまうと
いう問題が生じる。このとき漏れ電流はさほど変化しな
いため、ウエハ電位の発生状況までは把握できない。(2) Even when a DC voltage is applied between the wafer and the dielectric to secure an electrostatic force for attracting the wafer, the degree of contact between the ground electrode and the wafer is reduced, and the ground electrode is not affected with time. The contact resistance between the wafer and the ground electrode may be increased due to deterioration. In this case, a leakage current flowing through the wafer generates a surface potential on the wafer. Since this potential generates an unnecessary electric field near the wafer, there is a problem that the trajectory is bent with respect to the irradiated electron beam. At this time, since the leakage current does not change much, it is not possible to grasp the state of generation of the wafer potential.
【００１３】本発明は以上の点に鑑みてなされ、その目
的は、この種の静電吸着装置において、第１には試料
（例えばシリコンウエハ）の裏面に絶縁物が形成されて
いる場合であっても、試料と接地電極間の導通状態（接
地状態）を検査でき（換言すればウエハが正常に静電吸
着されるかどうか検査でき）、第２には試料・接地電極
間の導通状態の検査に併せて試料の電子線照射（例えば
電子線描画や電子顕微鏡における電子線走査）に支障と
なる電位が発生しているか否かを検査可能にする装置を
提供することにある。The present invention has been made in view of the above points, and an object of the present invention is to firstly provide a case in which an insulator is formed on the back surface of a sample (for example, a silicon wafer) in this kind of electrostatic chuck. However, the conduction state (ground state) between the sample and the ground electrode can be inspected (in other words, whether or not the wafer is normally electrostatically attracted) can be inspected. Second, the conduction state between the sample and the ground electrode can be inspected. It is an object of the present invention to provide an apparatus capable of inspecting whether or not a potential that interferes with electron beam irradiation (for example, electron beam drawing or electron beam scanning in an electron microscope) of a sample is generated in addition to the inspection.
【００１４】[0014]
【課題を解決するための手段】本発明は上記課題を解決
するため、次のように構成される。The present invention is configured as follows to solve the above-mentioned problems.
【００１５】第１の発明は、試料を保持する部材が誘電
体より成り、この誘電体上の試料に接触して該試料を接
地する接地電極を備え、この接地電極と前記誘電体側に
設けた電極との間に直流電圧を印加して前記試料・誘電
体間に静電力を発生させ、この静電力により前記試料を
前記誘電体上に吸着する静電吸着装置において、前記接
地電極以外に、前記誘電体上の前記試料に接触する抵抗
測定用の電極が配置され、この抵抗測定用電極と前記接
地電極の間の抵抗値を測定する抵抗測定回路と、この抵
抗測定値から前記試料の接地具合を判定する判定手段
と、を備えたことを特徴とする。According to a first aspect of the present invention, the member holding the sample is made of a dielectric material, and is provided with a ground electrode for contacting the sample on the dielectric and grounding the sample, and is provided on the ground electrode and the dielectric side. Applying a DC voltage between the electrodes and generating an electrostatic force between the sample and the dielectric, in the electrostatic chucking device that sucks the sample on the dielectric by the electrostatic force, in addition to the ground electrode, An electrode for resistance measurement that is in contact with the sample on the dielectric is disposed, a resistance measurement circuit that measures a resistance value between the resistance measurement electrode and the ground electrode, and grounding of the sample from the resistance measurement value. Determining means for determining the condition.
【００１６】このような構成によれば、試料表面側に接
地電極のほかに抵抗測定用電極を接触させて、この抵抗
測定用電極と前記接地電極の間の抵抗値を抵抗測定回路
を用いて測定できる。この抵抗値は、接地不良の場合に
は大きくなるので、抵抗値が所定の基準値（設定値）よ
りも大きい場合には接地不良と判定する。本発明によれ
ばウエハ裏面に絶縁物が成膜されていても、試料表面で
の抵抗測定用電極の接触（絶縁物を介さない接触）を確
保することで、試料の接地具合の検査を可能にする。According to such a configuration, a resistance measuring electrode is brought into contact with the surface of the sample in addition to the ground electrode, and the resistance between the resistance measuring electrode and the ground electrode is measured using a resistance measuring circuit. Can be measured. Since this resistance value becomes large in the case of poor grounding, if the resistance value is larger than a predetermined reference value (set value), it is determined that the grounding is poor. According to the present invention, even if an insulator is formed on the back surface of the wafer, it is possible to inspect the grounding condition of the sample by securing the contact of the electrode for resistance measurement on the surface of the sample (contact not through the insulator). To
【００１７】第２の発明は、第１の発明同様に、試料を
保持する部材が誘電体より成り、この誘電体上の試料に
接触して該試料を接地する接地電極を備え、この接地電
極と前記誘電体側に設けた電極との間に直流電圧を印加
して前記試料・誘電体間に静電力を発生させ、この静電
力により前記試料を前記誘電体上に吸着する静電吸着装
置において、前記接地電極以外に、前記誘電体上の前記
試料に接触する電位測定用の電極が配置され、この電位
測定用電極を用いて前記直流電圧印加時の試料の表面電
位を測定する電位測定回路と、この電位測定値から前記
試料の接地具合を判定する判定手段と、を備えたことを
特徴とする。According to a second aspect of the present invention, similarly to the first aspect, the member holding the sample is made of a dielectric, and is provided with a ground electrode for contacting the sample on the dielectric and grounding the sample. And an electrode provided on the dielectric side to apply a DC voltage to generate an electrostatic force between the sample and the dielectric, and the electrostatic attraction device for attracting the sample on the dielectric by the electrostatic force. In addition to the ground electrode, an electrode for measuring a potential that is in contact with the sample on the dielectric is disposed, and a potential measurement circuit that measures a surface potential of the sample when the DC voltage is applied using the potential measurement electrode And determining means for determining the grounding condition of the sample from the measured potential value.
【００１８】このような構成によれば、試料表面側に接
地電極のほかに電位測定用電極を接触させ、前記静電吸
着に用いる直流電圧を印加した時の試料上の表面電位を
電位測定回路により測定することができる。この電位測
定値は、試料の接地不良（接地電極と試料間の接触不
良，接地電極劣化など）をきたした場合に大きくなるの
で、電位測定値が所定の基準値（設定値）よりも大きい
場合には接地不良と判定する。本発明によれば、接地不
良の判定のほかに、試料に表面電位を発生する状況を電
子描画等の荷電粒子の照射に際して事前にとらえて、そ
の対策を講じることが可能になる。According to this configuration, the potential measurement electrode is brought into contact with the surface of the sample in addition to the ground electrode, and the surface potential on the sample when the DC voltage used for the electrostatic adsorption is applied is measured by the potential measurement circuit. Can be measured. Since the measured potential value becomes large when a ground failure of the sample (poor contact between the ground electrode and the sample, deterioration of the ground electrode, etc.) occurs, when the measured potential value is larger than a predetermined reference value (set value). Is determined to be poor grounding. ADVANTAGE OF THE INVENTION According to this invention, in addition to the determination of a grounding failure, it is possible to take a measure against the situation in which a surface potential is generated on a sample in advance when irradiating with charged particles such as electronic drawing.
【００１９】第３の発明は、上記第１の発明における抵
抗測定用電極，抵抗測定回路，判定手段と、第２の発明
における電位測定用電極，電位測定回路，判定手段を備
え、且つ前記抵抗測定用電極及び前記電位測定用電極が
兼用のものであり、この兼用電極が前記抵抗測定回路と
前記電位測定回路に対して切替可能に接続されているこ
とを特徴とする。According to a third aspect of the present invention, there is provided the electrode for resistance measurement, the resistance measuring circuit, and the judging means according to the first aspect of the invention, and the electrode for potential measurement, the potential measuring circuit, and the judging means according to the second aspect of the invention. The measurement electrode and the potential measurement electrode are shared, and the shared electrode is switchably connected to the resistance measurement circuit and the potential measurement circuit.
【００２０】このような構成によれば、上記第１の発明
と第２の発明の作用を期待することができる。According to such a configuration, the effects of the first and second inventions can be expected.
【００２１】[0021]
【発明の実施の形態】本発明の一実施例を図１により説
明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG.
【００２２】図１は本実施例に係る静電吸着装置の構成
図である。図１において、ウエハ１を静電吸着保持する
誘電体（試料ホルダ）２には電極３が埋め込まれてお
り、電極３は静電吸着用直流電源４の（＋）側と接続さ
れている。FIG. 1 is a configuration diagram of the electrostatic suction device according to the present embodiment. In FIG. 1, an electrode 3 is embedded in a dielectric (sample holder) 2 for electrostatically holding a wafer 1, and the electrode 3 is connected to the (+) side of a DC power supply 4 for electrostatic adsorption.
【００２３】この誘電体２は導電性を持つベースパレッ
ト５上に取付られており、ベースパレット５は電位が０
となるように接地されている。ウエハ１の表面には、ば
ね６の弾性力を利用して、接地電極たる導電性ピン７が
押しつけられている。The dielectric 2 is mounted on a conductive base pallet 5 having a potential of 0.
It is grounded so that A conductive pin 7 serving as a ground electrode is pressed against the surface of the wafer 1 by using the elastic force of a spring 6.
【００２４】この接地電極７は、ばね６を介してベース
パレット５とも導通があり、ウエハ１を接地電位にする
機能を有する。The ground electrode 7 is also electrically connected to the base pallet 5 via the spring 6, and has a function of setting the wafer 1 to a ground potential.
【００２５】さらに、ベースパレット５とは絶縁された
形態で、後述の抵抗測定用及び電位測定用として兼用さ
れる電極（導電性ピン）８がばね６´によりウエハ１上
に押しつけられている。この兼用電極８は、抵抗測定回
路９、電位測定回路１０、および接地電位に切り替えら
れるように、スイッチ１１と接続されている。Further, in a form insulated from the base pallet 5, an electrode (conductive pin) 8, which is also used for resistance measurement and potential measurement described later, is pressed onto the wafer 1 by a spring 6 '. The dual-purpose electrode 8 is connected to a switch 11 so as to be switched to a resistance measuring circuit 9, a potential measuring circuit 10, and a ground potential.
【００２６】以下、本実施例の動作について説明する。The operation of this embodiment will be described below.
【００２７】誘電体２の吸着面に置かれたウエハ１の表
面には、接地電極７および抵抗値・電位測定用（兼用）
の電極８が押しつけられている（なお、ウエハ１表面に
おける電極８の押しつけ位置となる個所では酸化膜等の
絶縁物が局部的に除去され、また、この電極接触部位は
電子線描画領域から外れた個所にある）。On the surface of the wafer 1 placed on the suction surface of the dielectric 2, a ground electrode 7 and a resistance / potential measurement (also used)
(The insulator such as an oxide film is locally removed at a position where the electrode 8 is pressed on the surface of the wafer 1, and the electrode contact portion deviates from the electron beam drawing area. Place).
【００２８】この状態で、先ずは、静電吸着の前にスイ
ッチ１１を接点ａの位置に切り替えて、電極８を抵抗測
定回路９と接続する。これにより電極８は抵抗測定用電
極となり、接地電極７及び抵抗測定用電極８間の抵抗値
が抵抗測定回路９により測定される。In this state, first, the switch 11 is switched to the position of the contact a before the electrostatic attraction, and the electrode 8 is connected to the resistance measuring circuit 9. As a result, the electrode 8 becomes a resistance measurement electrode, and the resistance value between the ground electrode 7 and the resistance measurement electrode 8 is measured by the resistance measurement circuit 9.
【００２９】この測定値がある設定値（例えば100kΩ）
以下かどうかを、判定回路１２によって検出する。設定
値（基準値）以上の場合、接地電極７とウエハ１間の導
通不良、もしくは接地電極７の劣化（寿命）等を原因と
した接地不良が生じているものと判断される。この場合
には、接地電極７の接触状態をチェックして電極７，８
を再駆動し（電極７，８間の抵抗値再測定を行い）、そ
れでも測定値（抵抗値）が設定値以上の場合には、接地
電極７の新品への交換を行う。This measured value is a certain set value (for example, 100 kΩ)
It is detected by the determination circuit 12 whether or not it is below. If the value is equal to or larger than the set value (reference value), it is determined that a poor connection between the ground electrode 7 and the wafer 1 or a poor ground due to deterioration (life) of the ground electrode 7 has occurred. In this case, the contact state of the ground electrode 7 is checked and the electrodes 7 and 8 are checked.
Is re-driven (the resistance value between the electrodes 7 and 8 is re-measured). If the measured value (resistance value) is still equal to or greater than the set value, the ground electrode 7 is replaced with a new one.
【００３０】上記測定値が設定値以下の場合、スイッチ
１３を閉じて静電吸着用の直流電圧源４により誘電体２
に電圧を印加し、誘電体２とウエハ１間に生じた静電力
により、ウエハ１を誘電体２の吸着面に吸着させる。If the measured value is equal to or less than the set value, the switch 13 is closed and the dielectric 2 is turned on by the DC voltage source 4 for electrostatic attraction.
And the wafer 1 is attracted to the attracting surface of the dielectric 2 by an electrostatic force generated between the dielectric 2 and the wafer 1.
【００３１】この場合、誘電体２からウエハ１にかけて
リーク電流が流れるため、接地電極７とウエハ１との接
触抵抗により、ウエハ１には表面電位が発生する。ここ
で、スイッチ１１を接点ｂの位置に切り替え、電極８を
電位測定回路１０側に接続する。これにより電極８は電
位測定用電極となり、電位測定回路１０によってウエハ
１の表面電位が測定される。この電位測定値がある設定
値（例えば500mV）以下かどうかを、判定回路１２によ
って検出する。設定値以上の場合、接地電極７の不具合
として、接地電極７の接触状態をチェックして電極８を
再駆動し（電極８によるウエハ電位測定）、それでも電
位測定値が設定値以上の場合には、接地電極７の新品へ
の交換を行う。In this case, since a leak current flows from the dielectric 2 to the wafer 1, a surface potential is generated on the wafer 1 due to the contact resistance between the ground electrode 7 and the wafer 1. Here, the switch 11 is switched to the position of the contact b, and the electrode 8 is connected to the potential measuring circuit 10 side. As a result, the electrode 8 becomes a potential measuring electrode, and the surface potential of the wafer 1 is measured by the potential measuring circuit 10. The determination circuit 12 detects whether or not the measured potential value is equal to or less than a set value (for example, 500 mV). If the measured value is equal to or larger than the set value, the contact state of the ground electrode 7 is checked and the electrode 8 is driven again (wafer potential measurement using the electrode 8). Then, the ground electrode 7 is replaced with a new one.
【００３２】設定値以下の場合、ウエハ吸着が正常で表
面電位も許容以下であるとして、電子線の照射（描画、
観察等）を開始する。この際、スイッチ１１を接点ｃの
位置に切り替える。これにより電極８は接地電極とな
り、接地電極７と相俟ってウエハ１の接地強化が行われ
る。例えば、電子線描画時には接地電極が２つになるた
め、ウエハ１との接触抵抗が半分になり、ウエハ電位が
小さくなる。If the value is equal to or less than the set value, it is determined that wafer suction is normal and the surface potential is not more than an allowable value, and the irradiation of electron beam (drawing
Observation). At this time, the switch 11 is switched to the position of the contact c. As a result, the electrode 8 becomes a ground electrode, and the grounding of the wafer 1 is strengthened together with the ground electrode 7. For example, when drawing an electron beam, since there are two ground electrodes, the contact resistance with the wafer 1 is halved, and the wafer potential is reduced.
【００３３】本実施例によれば次のような効果を奏す
る。According to this embodiment, the following effects are obtained.
【００３４】（１）ウエハ１表面上の接地電極７・抵抗
測定用電極８間の抵抗値を測定することで接地電極７の
接地具合を判定できるので、ウエハ１裏面に絶縁物が成
膜されていても、支障なくウエハの接地具合を判定する
ことができる。(1) The degree of grounding of the ground electrode 7 can be determined by measuring the resistance between the ground electrode 7 and the resistance measuring electrode 8 on the front surface of the wafer 1, so that an insulator is formed on the back surface of the wafer 1. The grounding condition of the wafer can be determined without any problem.
【００３５】（２）さらに、上記の抵抗測定値が正常値
の範囲内であっても、次にウエハ電位測定値からウエハ
の接地具合を判定するので、２重の検査により接地具合
を検査することにより、静電吸着時における吸着不良の
検出信頼性を向上させ、しかも、接地電極７の接触抵抗
に起因してウエハ１の表面電位が許容値を上回る時に
も、これを電子線照射前に検知して対処することができ
る。(2) Even if the measured resistance value is within the normal value range, the grounding state of the wafer is determined from the measured wafer potential value. Thereby, the reliability of detection of a suction failure at the time of electrostatic suction is improved, and even when the surface potential of the wafer 1 exceeds an allowable value due to the contact resistance of the ground electrode 7, it is necessary to reduce this before the electron beam irradiation. Detect and take action.
【００３６】（３）電子線をウエハ１に照射する場合に
は、２つの電極７，８が接地電極となるので、ウエハの
接触抵抗を従来の１／２にすることができ、ウエハの表
面電位（静電吸着及び電子線照射によるチャージアップ
により生じる電位）を小さくして、電子線の照射精度を
高めることができる。(3) When irradiating the wafer 1 with an electron beam, since the two electrodes 7 and 8 serve as ground electrodes, the contact resistance of the wafer can be reduced to half that of the conventional one, and the surface of the wafer 1 can be reduced. The potential (potential generated by charge up due to electrostatic attraction and electron beam irradiation) can be reduced, and the electron beam irradiation accuracy can be increased.
【００３７】図２は、上記した図１の静電吸着装置を搭
載した電子線描画装置の概略図である。FIG. 2 is a schematic diagram of an electron beam lithography apparatus equipped with the above-described electrostatic suction device of FIG.
【００３８】図２において、電子銃１４から放出された
電子ビーム１５は、アパーチャ１６および各レンズ１７
によって成形され、偏向板１８によってビーム軌道が所
望の描画位置にくるように制御されている。また、Ｘ
軸，Ｙ軸への移動機構を備えたステージ１９上には、静
電チャックとなる既述のベースパレット５および誘電体
２（試料ホルダ）が設置されている。誘電体２に吸着保
持されたウエハ１の描画位置はステージ１９の移動によ
って制御される。In FIG. 2, an electron beam 15 emitted from an electron gun 14 has an aperture 16 and each lens 17.
And the beam trajectory is controlled by the deflecting plate 18 so as to reach a desired drawing position. Also, X
The above-described base pallet 5 and dielectric 2 (sample holder) serving as an electrostatic chuck are placed on a stage 19 having a moving mechanism for moving the axis and the Y axis. The drawing position of the wafer 1 sucked and held by the dielectric 2 is controlled by the movement of the stage 19.
【００３９】図１の実施例でも述べた接地電極７と抵抗
測定用・電位測定用の兼用電極８とが描画対象となるウ
エハ１に接触している。電極８は電子線描画に際して前
述した抵抗測定回路９および電位測定回路１０に順番に
接続され、ウエハ１の吸着状況や発生電位を把握するこ
とが可能である。また、電極８は、電子線描画時には接
地に切り替わりる。したがって、本例の電子線描画装置
によれば、従来の装置に比べて安定した描画精度を維持
することができる。The ground electrode 7 and the dual-purpose electrode 8 for resistance measurement and potential measurement which are also described in the embodiment of FIG. 1 are in contact with the wafer 1 to be written. The electrode 8 is connected to the resistance measuring circuit 9 and the potential measuring circuit 10 described above in order to draw the electron beam, so that the state of suction of the wafer 1 and the generated potential can be grasped. The electrode 8 is switched to the ground when drawing an electron beam. Therefore, according to the electron beam lithography apparatus of the present embodiment, it is possible to maintain more stable lithography accuracy than the conventional apparatus.
【００４０】なお、上記実施例では、電極８を抵抗測定
用・電位測定用に兼用させているが、その他の実施形態
としては、電極８に対して抵抗測定回路９と電位測定回
路１０のいずれか一つを省略してもよい。In the above embodiment, the electrode 8 is used for both resistance measurement and potential measurement. However, in other embodiments, the electrode 8 may be used for either the resistance measurement circuit 9 or the potential measurement circuit 10. One of them may be omitted.
【００４１】例えば、静電チャックの検査系を、図４に
示すように電極８（抵抗測定用電極），抵抗測定回路９
で構成したり（課題を解決するための第１の発明に相当
する）、或いは図５に示すように電極８（電位測定用電
極），電位測定回路１０で構成したり（課題を解決する
ための第２の発明に相当する）、或いはこれらと図１に
示す接地電位切替接点ｃとの組合せで構成することも可
能である。For example, as shown in FIG. 4, the inspection system of the electrostatic chuck is composed of an electrode 8 (electrode for resistance measurement) and a resistance measurement circuit 9.
(Corresponding to a first invention for solving the problem), or as shown in FIG. 5, composed of an electrode 8 (electrode for measuring potential) and a potential measuring circuit 10 (for solving the problem). Or the combination of these with the ground potential switching contact c shown in FIG.
【００４２】[0042]
【発明の効果】第１の発明によれば、試料の裏面に絶縁
物が形成されている場合であっても、試料と接地電極間
の導通状態（接地状態）を検査でき、ひいては試料が正
常に静電吸着されるかどうか検査でき、静電吸着時にお
いて吸着不良の検出信頼性を向上させる。According to the first aspect of the present invention, even if an insulating material is formed on the back surface of the sample, the conduction state (ground state) between the sample and the ground electrode can be inspected, and the sample can be properly operated. It is possible to inspect whether or not electrostatic adsorption is performed, and to improve the reliability of detection of a suction failure during electrostatic adsorption.
【００４３】第２の発明によれば、試料と接地電極間の
導通状態（接地状態）ひいては試料が正常に静電吸着さ
れるかどうか検査できるほかに、試料の電子線照射（例
えば電子線描画や電子顕微鏡における電子線走査）に支
障となる電位が発生しているか否かを検査可能にして、
電子線描画精度や電子顕微鏡の測定精度を維持すること
ができる。According to the second aspect of the present invention, it is possible to inspect whether the sample is in a conductive state (ground state) between the sample and the ground electrode, and whether the sample is normally electrostatically attracted. And electron beam scanning in an electron microscope) to check whether a potential that interferes with
The electron beam drawing accuracy and the measurement accuracy of the electron microscope can be maintained.
【００４４】第３の発明によれば、上記第１，第２の発
明の効果を奏することができる。According to the third aspect, the effects of the first and second aspects can be obtained.
【図１】本発明の一実施例に係る静電吸着装置の構成図
である。FIG. 1 is a configuration diagram of an electrostatic suction device according to an embodiment of the present invention.
【図２】本発明の静電吸着装置を搭載した電子線描画装
置の概略図である。FIG. 2 is a schematic view of an electron beam lithography apparatus equipped with the electrostatic suction device of the present invention.
【図３】従来の静電吸着装置の概略図である。FIG. 3 is a schematic view of a conventional electrostatic suction device.
【図４】本発明の他の実施例に係る静電吸着装置の構成
図である。FIG. 4 is a configuration diagram of an electrostatic attraction device according to another embodiment of the present invention.
【図５】本発明の他の実施例に係る静電吸着装置の構成
図である。FIG. 5 is a configuration diagram of an electrostatic suction device according to another embodiment of the present invention.
１…ウエハ（試料）、２…誘電体（試料保持部材）、３
…電極、４…吸着用直流電源、５…ベースパレット、６
…押しつけばね、７…接地電極、８…抵抗測定用・電位
測定用の兼用電極、９…抵抗測定回路、１０…電位測定
回路、１１…測定モード切り替えスイッチ、１２…判定
回路、１３…吸着ON/OFFスイッチ、１４…電子銃、１５
…電子ビーム、１６…アパーチャ、１７…レンズ、１８
…偏向板、１９…ステージ、２０…電流計。DESCRIPTION OF SYMBOLS 1 ... Wafer (sample), 2 ... Dielectric (sample holding member), 3
... Electrode, 4 ... DC power supply for adsorption, 5 ... Base pallet, 6
... pressing spring, 7 ... ground electrode, 8 ... dual-purpose electrode for resistance measurement and potential measurement, 9 ... resistance measurement circuit, 10 ... potential measurement circuit, 11 ... measurement mode changeover switch, 12 ... determination circuit, 13 ... suction ON / OFF switch, 14 ... electron gun, 15
... Electron beam, 16 ... Aperture, 17 ... Lens, 18
... deflecting plate, 19 ... stage, 20 ... ammeter.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 池田 和典 茨城県ひたちなか市大字市毛882番地 株 式会社日立製作所計測器事業部内 (72)発明者 福嶋 芳雅 茨城県ひたちなか市大字市毛882番地 株 式会社日立製作所計測器事業部内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Ikeda 882-Chair, Oaza-shi, Hitachinaka-city, Ibaraki Pref.Hitachi, Ltd.Measurement Division, Hitachi, Ltd. Within Hitachi Measuring Instruments Division
Claims (5)
この誘電体上の試料に接触して該試料を接地する接地電
極を備え、この接地電極と前記誘電体側に設けた電極と
の間に直流電圧を印加して前記試料・誘電体間に静電力
を発生させ、この静電力により前記試料を前記誘電体上
に吸着する静電吸着装置において、 前記接地電極以外に、前記誘電体上の前記試料に接触す
る抵抗測定用の電極が配置され、 この抵抗測定用電極と前記接地電極の間の抵抗値を測定
する抵抗測定回路と、 この抵抗測定値から前記試料の接地具合を判定する判定
手段と、を備えたことを特徴とする静電吸着装置。1. A member holding a sample is made of a dielectric,
A ground electrode for contacting the sample on the dielectric and grounding the sample; applying a DC voltage between the ground electrode and an electrode provided on the dielectric to apply an electrostatic force between the sample and the dielectric; And an electrostatic chucking device for attracting the sample onto the dielectric by the electrostatic force, wherein an electrode for resistance measurement that is in contact with the sample on the dielectric is arranged in addition to the ground electrode. An electrostatic chuck device comprising: a resistance measurement circuit that measures a resistance value between a resistance measurement electrode and the ground electrode; and a determination unit that determines a grounding state of the sample from the resistance measurement value. .
この誘電体上の試料に接触して該試料を接地する接地電
極を備え、この接地電極と前記誘電体側に設けた電極と
の間に直流電圧を印加して前記試料・誘電体間に静電力
を発生させ、この静電力により前記試料を前記誘電体上
に吸着する静電吸着装置において、 前記接地電極以外に、前記誘電体上の前記試料に接触す
る電位測定用の電極が配置され、 この電位測定用電極を用いて前記直流電圧印加時の試料
の表面電位を測定する電位測定回路と、 この電位測定値から前記試料の接地具合を判定する判定
手段と、を備えたことを特徴とする静電吸着装置。2. A member holding a sample is made of a dielectric,
A ground electrode for contacting the sample on the dielectric and grounding the sample; applying a DC voltage between the ground electrode and an electrode provided on the dielectric to apply an electrostatic force between the sample and the dielectric; In the electrostatic chucking device for attracting the sample onto the dielectric by the electrostatic force, an electrode for measuring the potential in contact with the sample on the dielectric is arranged in addition to the ground electrode. A potential measurement circuit for measuring a surface potential of the sample when the DC voltage is applied using an electrode for potential measurement; and a determination unit for determining a grounding state of the sample from the potential measurement value. Electrostatic suction device.
この誘電体上の試料に接触して該試料を接地する接地電
極を備え、この接地電極と前記誘電体側に設けた電極と
の間に直流電圧を印加して前記試料・誘電体間に静電力
を発生させ、この静電力により前記試料を前記誘電体上
に吸着する静電吸着装置において、 請求項１のおける前記抵抗測定用電極と前記抵抗測定回
路と前記判定手段と、請求項２における前記電位測定用
電極と前記電位測定回路と前記判定手段とを備え、且つ
前記抵抗測定用電極及び前記電位測定用電極が兼用され
ており、 この兼用電極が前記抵抗測定回路と前記電位測定回路に
対して切替可能に接続されていることを特徴とする静電
吸着装置。3. A member holding a sample is made of a dielectric,
A ground electrode for contacting the sample on the dielectric and grounding the sample; applying a DC voltage between the ground electrode and an electrode provided on the dielectric to apply an electrostatic force between the sample and the dielectric; And an electrostatic attraction device for attracting the sample onto the dielectric by the electrostatic force, wherein the electrode for resistance measurement, the resistance measurement circuit, the determination means, and the determination means according to claim 1, wherein An electrode for potential measurement, the potential measurement circuit, and the determination means are provided, and the electrode for resistance measurement and the electrode for potential measurement are also used, and the dual-purpose electrode is provided for the resistance measurement circuit and the potential measurement circuit. An electrostatic attraction device characterized by being connected in a switchable manner.
線を照射する場合には、その電子線照射に際して前記抵
抗測定用電極又は前記電位測定用電極又は前記抵抗測定
用・電位測定用の兼用電極が接地電位に切替接続される
構成としてある請求項１又は請求項２又は請求項３記載
の静電吸着装置。4. The method according to claim 1, wherein the sample is an object to be irradiated with an electron beam, and when the sample is irradiated with an electron beam, the electrode for resistance measurement or the electrode for potential measurement or the electrode for resistance measurement / potential measurement at the time of electron beam irradiation. 4. The electrostatic attraction device according to claim 1, wherein the dual-purpose electrode is configured to be switched to a ground potential.
エハを載置して電子線描画を行う電子線描画装置におい
て、 請求項１又は請求項２又は請求項３又は請求項４記載の
静電吸着装置が半導体ウエハを保持する機構を構成し、
このうち前記誘電体が前記ステージ上に設置され、電子
線描画に際して前記抵抗測定用電極又は前記電位測定用
電極又は前記抵抗測定用・電位測定用の兼用電極を用い
て前記半導体ウエハの接地具合を検査するよう設定され
ていることを特徴とする電子線描画装置。5. An electron beam lithography apparatus for performing electron beam lithography by mounting a semiconductor wafer on a stage having a moving mechanism, wherein the electrostatic chuck according to claim 1, 2, 3 or 4. The device constitutes a mechanism for holding the semiconductor wafer,
Among them, the dielectric is placed on the stage, and at the time of electron beam drawing, grounding of the semiconductor wafer is performed using the resistance measurement electrode or the potential measurement electrode or the resistance measurement / potential measurement combined electrode. An electron beam lithography apparatus set to be inspected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22606197A JP3373762B2 (en) | 1997-08-22 | 1997-08-22 | Electrostatic suction device and electron beam lithography device using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22606197A JP3373762B2 (en) | 1997-08-22 | 1997-08-22 | Electrostatic suction device and electron beam lithography device using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1167884A true JPH1167884A (en) | 1999-03-09 |
| JP3373762B2 JP3373762B2 (en) | 2003-02-04 |
Family
ID=16839197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22606197A Expired - Fee Related JP3373762B2 (en) | 1997-08-22 | 1997-08-22 | Electrostatic suction device and electron beam lithography device using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3373762B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006108643A (en) * | 2004-09-10 | 2006-04-20 | Hitachi High-Technologies Corp | For charged particle beam lithography device and charged particle beam lithography method |
| JP2006516675A (en) * | 2002-09-11 | 2006-07-06 | バリアン・セミコンダクター・イクイップメント・アソシエーツ・インコーポレーテッド | Active method and system for establishing electrical contact |
| EP1788615A2 (en) * | 2005-11-17 | 2007-05-23 | E-Beam Corporation | Substrate treatment apparatus and substrate treatment method |
| JP2007266361A (en) * | 2006-03-29 | 2007-10-11 | Nuflare Technology Inc | Grounding mechanism of substrate, and charged particle beam drawing apparatus |
| JP2007279070A (en) * | 2007-07-23 | 2007-10-25 | Hitachi Ltd | Sample analysis method |
| WO2008068815A1 (en) * | 2006-11-30 | 2008-06-12 | Advantest Corporation | Electron beam exposure device |
| JP2010272586A (en) * | 2009-05-19 | 2010-12-02 | Hitachi High-Technologies Corp | Charged particle beam device |
| JP2016021292A (en) * | 2014-07-14 | 2016-02-04 | 株式会社日立ハイテクノロジーズ | Charged particle beam device |
| JP2018014383A (en) * | 2016-07-20 | 2018-01-25 | 株式会社ディスコ | Adsorption confirmation method, desorption confirmation method, and decompression processing apparatus |
| JP2020035984A (en) * | 2018-08-31 | 2020-03-05 | 株式会社ニューフレアテクノロジー | Abnormality determination method and drawing apparatus |
-
1997
- 1997-08-22 JP JP22606197A patent/JP3373762B2/en not_active Expired - Fee Related
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006516675A (en) * | 2002-09-11 | 2006-07-06 | バリアン・セミコンダクター・イクイップメント・アソシエーツ・インコーポレーテッド | Active method and system for establishing electrical contact |
| JP4637684B2 (en) * | 2004-09-10 | 2011-02-23 | 株式会社日立ハイテクノロジーズ | Charged particle beam application equipment |
| JP2006108643A (en) * | 2004-09-10 | 2006-04-20 | Hitachi High-Technologies Corp | For charged particle beam lithography device and charged particle beam lithography method |
| EP1788615A2 (en) * | 2005-11-17 | 2007-05-23 | E-Beam Corporation | Substrate treatment apparatus and substrate treatment method |
| EP1788615A3 (en) * | 2005-11-17 | 2011-08-24 | Tokyo Electron Limited | Substrate treatment apparatus and substrate treatment method |
| JP2007266361A (en) * | 2006-03-29 | 2007-10-11 | Nuflare Technology Inc | Grounding mechanism of substrate, and charged particle beam drawing apparatus |
| JPWO2008068815A1 (en) * | 2006-11-30 | 2010-03-11 | 株式会社アドバンテスト | Electron beam exposure system |
| WO2008068815A1 (en) * | 2006-11-30 | 2008-06-12 | Advantest Corporation | Electron beam exposure device |
| JP5047192B2 (en) * | 2006-11-30 | 2012-10-10 | 株式会社アドバンテスト | Electron beam exposure system |
| JP4534235B2 (en) * | 2007-07-23 | 2010-09-01 | 株式会社日立製作所 | Sample analysis method |
| JP2007279070A (en) * | 2007-07-23 | 2007-10-25 | Hitachi Ltd | Sample analysis method |
| JP2010272586A (en) * | 2009-05-19 | 2010-12-02 | Hitachi High-Technologies Corp | Charged particle beam device |
| JP2016021292A (en) * | 2014-07-14 | 2016-02-04 | 株式会社日立ハイテクノロジーズ | Charged particle beam device |
| JP2018014383A (en) * | 2016-07-20 | 2018-01-25 | 株式会社ディスコ | Adsorption confirmation method, desorption confirmation method, and decompression processing apparatus |
| JP2020035984A (en) * | 2018-08-31 | 2020-03-05 | 株式会社ニューフレアテクノロジー | Abnormality determination method and drawing apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3373762B2 (en) | 2003-02-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4637684B2 (en) | Charged particle beam application equipment | |
| US4415851A (en) | System for contactless testing of multi-layer ceramics | |
| JP4828162B2 (en) | Electron microscope application apparatus and sample inspection method | |
| JPH03135778A (en) | Method and device for conducting opening/short circuit test of electric circuit in noncontact manner | |
| WO2010097858A1 (en) | Electron microscope, and specimen holding method | |
| JP3373762B2 (en) | Electrostatic suction device and electron beam lithography device using the same | |
| TWI779070B (en) | Probe device | |
| TW201110254A (en) | Wafer grounding and biasing method, apparatus, and application | |
| TW202038019A (en) | Object table | |
| JP2001174499A (en) | Apparatus and method for testing electric trace with use of photoelectric effect | |
| US20080296496A1 (en) | Method and apparatus of wafer surface potential regulation | |
| JP6411799B2 (en) | Charged particle beam equipment | |
| JPH01321136A (en) | Deterioration sensing device for electrostatic chuck | |
| TW202123287A (en) | Method, apparatus, and system for wafer grounding | |
| JP3123956B2 (en) | Electrostatic suction device and electron beam lithography device using the same | |
| JP5401343B2 (en) | Power supply circuit for electrostatic chuck and electrostatic chuck device | |
| JP2008515226A (en) | Method and apparatus for measuring the density of defects and / or impurities in a semiconductor wafer | |
| JP3458548B2 (en) | Work potential measurement method | |
| JPH09246366A (en) | Electrostatic clamping device and electron beam drawing device provided therewith | |
| JPH1167647A (en) | Method and apparatus for preventing charging of photomask | |
| JPH07130827A (en) | Electrostatic wafer chuck | |
| JPH07283296A (en) | Electrostatic attraction device | |
| JP2007019524A (en) | Separation state determining method and vacuum processing device | |
| JPH09167593A (en) | Ion implantation device | |
| JP4029668B2 (en) | Ion beam irradiation equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313114 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071122 Year of fee payment: 5 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071122 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081122 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091122 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101122 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101122 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111122 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111122 Year of fee payment: 9 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313117 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111122 Year of fee payment: 9 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111122 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121122 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121122 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131122 Year of fee payment: 11 |
|
| LAPS | Cancellation because of no payment of annual fees |