JPH09129166A - Electron gun - Google Patents
Electron gunInfo
- Publication number
- JPH09129166A JPH09129166A JP7287113A JP28711395A JPH09129166A JP H09129166 A JPH09129166 A JP H09129166A JP 7287113 A JP7287113 A JP 7287113A JP 28711395 A JP28711395 A JP 28711395A JP H09129166 A JPH09129166 A JP H09129166A
- Authority
- JP
- Japan
- Prior art keywords
- cathode
- electron beam
- anode
- electron gun
- electron
- 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- Withdrawn
Links
- 238000010894 electron beam technology Methods 0.000 claims abstract description 57
- 230000000007 visual effect Effects 0.000 abstract description 6
- 229910052746 lanthanum Inorganic materials 0.000 abstract description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 abstract description 2
- 229910025794 LaB6 Inorganic materials 0.000 abstract 1
- 230000003287 optical effect Effects 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 239000000758 substrate Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 3
- 230000005684 electric field Effects 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- NCGICGYLBXGBGN-UHFFFAOYSA-N 3-morpholin-4-yl-1-oxa-3-azonia-2-azanidacyclopent-3-en-5-imine;hydrochloride Chemical compound Cl.[N-]1OC(=N)C=[N+]1N1CCOCC1 NCGICGYLBXGBGN-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 238000005094 computer simulation Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000001894 space-charge-limited current method Methods 0.000 description 1
Landscapes
- Electron Sources, Ion Sources (AREA)
- Electron Beam Exposure (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えば電子線転写
装置等の電子線源として使用される電子銃に関し、特に
大きなエミッタンスを有し広い視野を均一な強度分布で
照射するために使用して好適な電子銃に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun used as an electron beam source for, for example, an electron beam transfer device, and particularly to use it for irradiating a wide field of view with a uniform intensity distribution having a large emittance. It relates to a suitable electron gun.
【０００２】[0002]
【従来の技術】半導体集積回路等の原版としてのマスク
パターンを半導体ウエハ等の基板上に転写するような場
合に、電子銃から放出される電子ビームをマスクパター
ンに照射し、マスクパターンを通過した電子ビームを電
子光学鏡筒内で制御してその基板上に導き、その基板上
にそのマスクパターンの縮小像を転写する電子線縮小転
写装置が使用されている。最近は、マスクパターンを高
いスループット（生産性）で転写することが求められて
いるため、マスクパターンを第１方向に複数の主視野に
分割し、これらの主視野をそれぞれその第１方向に直交
する第２方向に複数の副視野に分割し、これらの副視野
を単位としてマスクパターンを順次基板上に転写すると
共に、その第１方向にマスクと基板とを同期して走査し
て転写を行う所謂分割転写方式の電子線縮小転写装置も
開発されている。2. Description of the Related Art When a mask pattern as an original plate of a semiconductor integrated circuit or the like is transferred onto a substrate such as a semiconductor wafer, an electron beam emitted from an electron gun is applied to the mask pattern and passes through the mask pattern. 2. Description of the Related Art An electron beam reduction transfer device is used which controls an electron beam in an electron optical lens barrel to guide it onto the substrate and transfers a reduced image of the mask pattern onto the substrate. Recently, since it is required to transfer a mask pattern with high throughput (productivity), the mask pattern is divided into a plurality of main visual fields in the first direction, and these main visual fields are orthogonal to the first direction. In the second direction, the sub-fields are divided into a plurality of sub-fields of view, and the mask pattern is sequentially transferred onto the substrate in units of these sub-fields of view. In the first direction, the mask and the substrate are synchronously scanned and transferred. A so-called division transfer type electron beam reduction transfer device has also been developed.
【０００３】このような分割転写方式でスループットを
より高めるためには、転写単位である各副視野の面積を
広くすればよいが、そのためには広い視野に均一な強度
分布の電子ビームを照射できる電子銃が必要となる。斯
かる電子銃の特性を表すパラメータとして、図３に示す
ように、当該電子銃から放出される電子ビームＥＢによ
る電子線源の像であるクロスオーバ１８の直径ｄｇと、
そのクロスオーバ１８から放出される電子ビームの強度
が最大値の９９％となるときの電子ビームの開口全角２
・αｇ（αｇは開口半角）との積であるエミッタンスが
ある。即ち、次式が成立している。In order to further increase the throughput in such a division transfer method, the area of each sub-field of view, which is a transfer unit, may be widened. For that purpose, the wide field of view can be irradiated with an electron beam having a uniform intensity distribution. You need an electron gun. As shown in FIG. 3, as parameters showing the characteristics of such an electron gun, the diameter dg of the crossover 18, which is an image of the electron beam source by the electron beam EB emitted from the electron gun,
The full aperture angle 2 of the electron beam when the intensity of the electron beam emitted from the crossover 18 becomes 99% of the maximum value.
-There is emittance that is the product of αg (αg is the half angle of the aperture). That is, the following equation holds.
【０００４】エミッタンス＝ｄｇ・２αｇ （１） 一般に、エミッタンスの値が大きい程、より広い視野に
均一な強度分布の電子線を照射することができる。そし
て、後続の電子光学系で開口半角αｇを大きくすると、
クロスオーバの直径ｄｇが小さくなるため、（１）式の
エミッタンスの値は電子銃によって決定され、後続の電
子光学系によっては大きくすることができない。従来の
電子線縮小転写装置用の電子銃としては、開口半角αｇ
が例えば０．１ｍｒａｄ程度と小さい電子銃が用いられ
ていた。一方、クロスオーバの直径ｄｇは、電子銃の形
状にはあまり依存せず、通常１０μｍ程度である。従っ
て、従来の電子銃のエミッタンスは２μｍ・ｍｒａｄ程
度であった。この場合の電子銃の形状としては、例えば
カソードの電子ビームの放出面の曲率半径が２５０μｍ
程度のものが知られている。Emittance = dg · 2αg (1) In general, the larger the emittance value, the wider the field of view can be irradiated with an electron beam having a uniform intensity distribution. Then, if the aperture half angle αg is increased in the subsequent electron optical system,
Since the diameter dg of the crossover becomes small, the value of the emittance of the equation (1) is determined by the electron gun and cannot be increased by the subsequent electron optical system. As an electron gun for a conventional electron beam reduction transfer device, an opening half angle αg
However, an electron gun as small as about 0.1 mrad was used. On the other hand, the diameter dg of the crossover does not largely depend on the shape of the electron gun and is usually about 10 μm. Therefore, the emittance of the conventional electron gun is about 2 μm · mrad. As the shape of the electron gun in this case, for example, the radius of curvature of the electron beam emission surface of the cathode is 250 μm.
Something is known.
【０００５】これとは別に、カソードの電子ビームの放
出面を平面とした電子銃を温度制限電流の範囲（カソー
ドの温度が低く、電子ビームの電流がほぼカソードの温
度だけで決まる範囲）で使用し、且つクリティカル照明
条件で使用するようにした電子線縮小転写装置も知られ
ている。Separately from this, an electron gun whose cathode electron beam emission surface is a flat surface is used in a range of temperature limiting current (a range in which the temperature of the cathode is low and the electron beam current is determined almost only by the temperature of the cathode). In addition, an electron beam reduction transfer device adapted to be used under critical illumination conditions is also known.
【０００６】[0006]
【発明が解決しようとする課題】通常、電子線縮小転写
装置で使用される電子光学系の開口半角の最適値は、ビ
ーム分解能やビーム電流値に応じて変わるが、略々０．
５〜２ｍｒａｄ程度である。それに対して、従来のよう
に開口半角αｇが０．１ｍｒａｄ程度の小開口の電子銃
を使用すると、回折によるぼけや空間電荷効果によるぼ
けが大きくなり、高解像度の電子ビームを得ることがで
きなかったり、高いビーム電流が得られず、高解像度の
パターンを高スループットで転写できないといった不都
合があった。Normally, the optimum value of the aperture half angle of the electron optical system used in the electron beam reduction transfer apparatus varies depending on the beam resolution and the beam current value, but it is about 0.
It is about 5 to 2 mrad. On the other hand, when an electron gun having a small aperture with a half-angle αg of about 0.1 mrad is used as in the conventional case, blurring due to diffraction and blurring due to the space charge effect become large, and a high-resolution electron beam cannot be obtained. However, there is a problem that a high beam current cannot be obtained and a high resolution pattern cannot be transferred with high throughput.
【０００７】また、電子ビームの放出面を平面としたカ
ソードを備えた電子銃を温度制限電流の範囲で、且つク
リティカル照明条件で使用する場合には、先ず電子ビー
ムの放出面とマスク面とを光学的に共役にする必要性が
あるため、レンズを１段余計に設ける必要があり、電子
光学系が複雑化するという不都合がある。更に、カソー
ドの電子ビームの放出面の像をマスク面に投影している
ため、カソード表面の仕事関数のばらつきによってマス
ク面を照射する電子ビームの電流密度がばらつき、マス
ク上の各副視野の全体を一様な電流密度で転写すること
が困難で、線幅精度にばらつきが生じるという不都合が
あった。また、電子銃を温度制限電流の範囲で使用して
いるため、カソード温度が変動すると、電子銃電流、輝
度、及びビーム電流等が変動して、安定な転写ができな
い恐れもあって、実用性の点でも不安が残っていた。When an electron gun having a cathode whose emission surface is an electron beam is used in a temperature-limited current range and under critical illumination conditions, the emission surface of the electron beam and the mask surface are first separated. Since it is necessary to optically conjugate the lens, it is necessary to provide an extra lens in one step, and there is a disadvantage that the electron optical system becomes complicated. Furthermore, since the image of the emission surface of the electron beam of the cathode is projected onto the mask surface, the current density of the electron beam irradiating the mask surface varies due to the variation of the work function of the cathode surface, and the entire sub-field of view on the mask However, there is a problem that it is difficult to transfer with a uniform current density and the line width accuracy varies. In addition, since the electron gun is used in the range of the temperature limited current, if the cathode temperature changes, the electron gun current, the brightness, the beam current, etc. may change, and stable transfer may not be possible. I was still worried about this.
【０００８】本発明は斯かる点に鑑み、広い視野に均一
な強度分布の電子線を照射できると共に、動作が安定な
電子銃を提供することを目的とする。In view of the above problems, an object of the present invention is to provide an electron gun capable of irradiating a wide field of view with an electron beam having a uniform intensity distribution and having stable operation.
【０００９】[0009]
【課題を解決するための手段】本発明による電子銃は、
例えば図１に示すように、電子線の放出面（１ａ）が凸
の球面に形成されたカソード（１）と、このカソードに
対向するように配置された部分（２ａ）の内面がその電
子線の放出面（１ａ）と同心の球面に形成されたアノー
ド（２）と、を有するものである。An electron gun according to the present invention comprises:
For example, as shown in FIG. 1, a cathode (1) having an electron beam emitting surface (1a) formed in a convex spherical surface and an inner surface of a portion (2a) arranged so as to face the cathode are the electron beam. And an anode (2) formed on a spherical surface concentric with the emission surface (1a).
【００１０】斯かる本発明によれば、カソード（１）と
アノード（２）との間には、同心球の等ポテンシャル面
が形成され、カソード（１）から放出された電子線はこ
の等ポテンシャル面に直角に進む。即ち、カソード
（１）の放出面（１ａ）から法線方向に放出された電子
線は無収差の軌道に沿って進む。また、カソード（１）
の放出面（１ａ）の全面には、等しい電位が印加されて
いるため、放出面（１ａ）の全面から等しい電流密度の
電子銃電流が放出される。従って、広い放出角度に亘っ
て一様な電流密度の電子線が得られ、開口全角を大きく
できる。According to the present invention, a concentric sphere equipotential surface is formed between the cathode (1) and the anode (2), and the electron beam emitted from the cathode (1) has the same potential. Proceed perpendicular to the plane. That is, the electron beam emitted in the normal direction from the emission surface (1a) of the cathode (1) travels along an aberration-free trajectory. Also, the cathode (1)
Since the same potential is applied to the entire surface of the emission surface (1a), electron gun currents having the same current density are emitted from the entire surface of the emission surface (1a). Therefore, an electron beam having a uniform current density can be obtained over a wide emission angle, and the full aperture angle can be increased.
【００１１】一方、クロスオーバの直径は電子銃の形状
にあまり依存せず、１０μｍ程度である。そのため、ク
ロスオーバの直径と開口全角との積であるエミッタンス
を大きくでき、広い視野に均一な強度分布の電子線を照
射できる。例えば、１０００μｍ・ｍｒａｄのエミッタ
ンスを持つ電子銃を得るには、開口全角を１００ｍｒａ
ｄ以上とすればよい。このためには、例えば図１におい
て、アノード（２）の開口部（２ｃ）の直径がカソード
（１）の放出面（１ａ）の曲率中心を見込む角度（カソ
ード角）２・θを５．７°（＝１００ｍｒａｄ）以上と
すればよい。On the other hand, the diameter of the crossover does not much depend on the shape of the electron gun and is about 10 μm. Therefore, the emittance, which is the product of the diameter of the crossover and the full angle of aperture, can be increased, and an electron beam with a uniform intensity distribution can be applied to a wide field of view. For example, to obtain an electron gun having an emittance of 1000 μm · mrad, the full aperture angle is 100 mra.
It may be d or more. For this purpose, for example, in FIG. 1, an angle (cathode angle) 2 · θ in which the diameter of the opening (2c) of the anode (2) allows for the center of curvature of the emission surface (1a) of the cathode (1) is 5.7. It may be set to be at least ° (= 100 mrad).
【００１２】この場合、カソード（１）のその電子線の
放出面（１ａ）の曲率半径は２ｍｍ以上であることが望
ましい。これによって、カソード表面の電界強度が極端
に大きくなることが避けられ、１×１０+2〜１×１０+4
Ａ／（ｃｍ2 ｓｒ）程度の低輝度の電子銃が得られる。
また、アノード（２）に印加される電圧を可変として、
アノード（２）に印加される電圧を変化させることによ
って電子銃としての特性（電子銃電流、ビーム電流、輝
度、又はビーム電流密度等）を制御するようにしてもよ
い。In this case, the radius of curvature of the electron beam emitting surface (1a) of the cathode (1) is preferably 2 mm or more. As a result, it is possible to avoid the electric field strength on the cathode surface from becoming extremely large, and it is possible to avoid the occurrence of 1 × 10 +2 to 1 × 10 +4
An electron gun with a low brightness of about A / (cm 2 sr) can be obtained.
In addition, by changing the voltage applied to the anode (2),
The characteristics (electron gun current, beam current, brightness, beam current density, etc.) as an electron gun may be controlled by changing the voltage applied to the anode (2).
【００１３】更に、カソード（１）とアノード（２）と
の間にカソード（１）とアノード（２）との中間の電位
の第３の電極（３）を配置することが望ましい。この第
３の電極（３）の電位を変化させて、カソード（１）の
放出面（１ａ）で一様な電流密度の電子線を放出する範
囲を制御することによって、電子線の開口全角、ひいて
はエミッタンスを制御できる。Further, it is desirable to dispose a third electrode (3) having an intermediate potential between the cathode (1) and the anode (2) between the cathode (1) and the anode (2). By changing the potential of the third electrode (3) to control the range of emitting an electron beam having a uniform current density on the emission surface (1a) of the cathode (1), the full aperture angle of the electron beam, Consequently, emittance can be controlled.
【００１４】更に、カソード（１）の温度を加熱して、
空間電荷制限電流の範囲（カソードの温度を高めて熱電
子の放出量を増すことによって空間電荷を多くして、ビ
ーム電流の大きさが空間電荷層によって支配されるよう
な条件であり、このときのビーム電流は、ほぼアノード
の電圧によって決定される）でその電子銃を使用するこ
とが望ましい。これによって、カソード（１）の温度が
少しぐらい変動しても輝度等は変化しない。また、カソ
ード（１）の放出面（１ａ）で仕事関数の変動があって
も、方向による電子線の強度の一様性が損なわれない。Further, by heating the temperature of the cathode (1),
Space charge limited current range (a condition in which the space charge is increased by increasing the temperature of the cathode to increase the amount of thermionic emission, and the magnitude of the beam current is dominated by the space charge layer. Beam current is approximately determined by the anode voltage) and it is desirable to use the electron gun. As a result, the brightness and the like do not change even if the temperature of the cathode (1) changes slightly. Further, even if the work function varies on the emission surface (1a) of the cathode (1), the uniformity of the electron beam intensity depending on the direction is not impaired.
【００１５】[0015]
【発明の実施の形態】以下、本発明による電子銃の実施
の形態の一例につき図１を参照して説明する。図１は本
例の電子銃を示す一部を切り欠いた構成図を示し、この
図１において、カソード１は、六ホウ化ランタン（Ｌａ
Ｂ6 ）の２ｍｍ角の角柱状の単結晶の先端、即ち電子ビ
ームの放出面１ａを曲率半径ｒ１の球面に研磨して形成
した。本例では放出面１ａの曲率半径ｒ１は２ｍｍであ
る。また、カソード１の角柱状の部分の１対の対向する
面１ｂ，１ｃをそれぞれ加熱用グラファイト４Ａ，４Ｂ
を介して支持金具を兼ねる電極５Ａ，５Ｂで挟持してい
る。以下では、カソード１の角柱状の部分の中心軸を通
る直線を光軸ＡＸとして説明する。BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of an electron gun according to the present invention will be described below with reference to FIG. FIG. 1 is a partially cutaway view showing the electron gun of this example. In FIG. 1, the cathode 1 is lanthanum hexaboride (La).
The tip of a 2 mm square prismatic single crystal of B 6 ), that is, the electron beam emission surface 1a was polished to a spherical surface with a radius of curvature r1. In this example, the radius of curvature r1 of the emission surface 1a is 2 mm. In addition, the pair of facing surfaces 1b and 1c of the prismatic portion of the cathode 1 are heated to the heating graphites 4A and 4B, respectively.
It is sandwiched by the electrodes 5A and 5B which also serve as a support fitting. In the following, a straight line passing through the central axis of the prismatic portion of the cathode 1 will be described as the optical axis AX.
【００１６】そして、カソード１に対向するように、金
属板よりなる円筒状の側面部２ｂの下端に金属板よりな
る球面部２ａを取り付けた構造のアノード２を配置し、
その球面部２ａの内面を、カソード１の放出面１ａと同
心の曲率半径ｒ２の球面に加工した。また、球面部２ａ
の中央部には、光軸ＡＸを中心として直径Ｄ２の電子ビ
ーム通過用の開口部２ｃを設けた。本例では、曲率半径
ｒ２は１０ｍｍとし、開口部２ｃの直径Ｄ２は３．５ｍ
ｍとした。また、本例のカソード１は、軸対称ではない
加熱用グラファイト４Ａ，４Ｂ、及び電極５Ａ，５Ｂに
よる非軸対称電位の影響を受けている。そこで、このよ
うな非軸対称電位をシールドするために、カソード１と
アノード２との間に、金属板よりなる円筒状の側面部３
ｂの下端に、金属板よりなる内面の曲率半径ｒ３の球面
部３ａを取り付けた構造の第３の電極としてのウェーネ
ルト３を配置し、その球面部３ａの中央部には、光軸Ａ
Ｘを中心として直径Ｄ３の電子ビーム通過用の開口部３
ｃを設けた。半径ｒ３及び直径Ｄ３の一例については後
述する。本例では、ウェーネルト３の電位を変えること
によってエミッタンスを制御する。An anode 2 having a structure in which a spherical surface portion 2a made of a metal plate is attached to the lower end of a cylindrical side surface portion 2b made of a metal plate is arranged so as to face the cathode 1.
The inner surface of the spherical surface portion 2a was processed into a spherical surface having a radius of curvature r2 concentric with the emission surface 1a of the cathode 1. Also, the spherical surface portion 2a
An opening 2c for passing an electron beam having a diameter D2 centered on the optical axis AX is provided in the central part of the. In this example, the radius of curvature r2 is 10 mm, and the diameter D2 of the opening 2c is 3.5 m.
m. Further, the cathode 1 of this example is affected by the non-axisymmetric potential due to the non-axisymmetric heating graphites 4A and 4B and the electrodes 5A and 5B. Therefore, in order to shield such a non-axisymmetric potential, a cylindrical side surface portion 3 made of a metal plate is provided between the cathode 1 and the anode 2.
A Wehnelt 3 as a third electrode having a structure in which a spherical surface portion 3a having an inner surface made of a metal plate and having a radius of curvature r3 is attached to the lower end of b, the optical axis A is provided at the central portion of the spherical surface portion 3a.
An opening 3 for passing an electron beam having a diameter D3 centered on X
c is provided. An example of the radius r3 and the diameter D3 will be described later. In this example, the emittance is controlled by changing the potential of the Wehnelt 3.
【００１７】以上のように、カソード１、加熱用グラフ
ァイト４Ａ，４Ｂ、電極５Ａ，５Ｂ、アノード２、及び
ウェーネルト３より本例の電子銃１０が構成されてい
る。そして、電子銃１０の下端部に後続の電子光学系用
の金属板よりなるカバー７を配置した。カバー７の内面
を、カソード１の放出面１ａと同心の半径ｒ４（半径ｒ
４は電子銃１０からカバー７までの間隔によって定ま
る）の球面に加工し、カバー７の中央部に光軸ＡＸを中
心に電子ビーム通過用の開口部を設けた。更に、カバー
７を接地電位として、カソード１には−１００ｋＶの電
位を与え、アノード２にはカソード電位より＋１００Ｖ
〜＋２０００Ｖ高い可変の電位を与えた。そして、アノ
ード２の電位を変化させることによって、電子銃電流、
ビーム電流、輝度、又はビーム電流密度等を制御するよ
うにした。更に、カソード１の温度を加熱して、空間電
荷制限電流の範囲で使用した。As described above, the cathode 1, the heating graphites 4A, 4B, the electrodes 5A, 5B, the anode 2, and the Wehnelt 3 constitute the electron gun 10 of this embodiment. Then, the cover 7 made of a metal plate for the subsequent electron optical system is arranged at the lower end of the electron gun 10. The inner surface of the cover 7 has a radius r4 concentric with the emission surface 1a of the cathode 1 (radius r
4 is formed into a spherical surface (determined by the distance from the electron gun 10 to the cover 7), and an opening for passing an electron beam is provided at the center of the cover 7 around the optical axis AX. Further, the cover 7 is set to the ground potential, the potential of −100 kV is applied to the cathode 1, and the anode 2 is +100 V higher than the cathode potential.
A variable potential of ~ + 2000V higher was applied. Then, by changing the potential of the anode 2, the electron gun current,
The beam current, brightness, beam current density, etc. were controlled. Further, the cathode 1 was heated to a temperature within the range of the space charge limiting current.
【００１８】そして、ウェーネルト３の形状、及び電位
については、カソード１の表面での電流密度が一様にな
ること、及びカソード１の放出面１ａから法線方向に放
出された電子線が直進する軌道を示すこと、という２つ
の条件を課して、コンピュータによるシミュレーション
を行って決定した。その結果、ウェーネルト３の球面部
３ａの曲率半径ｒ３は４．５ｍｍ、開口部３ｃの直径は
５ｍｍが良く、アノード２の電位がカソード１より＋２
００Ｖ以上高い場合、ウェーネルト３に与える電圧はカ
ソード１より＋２００Ｖ高い値が良かった。Regarding the shape and potential of the Wehnelt 3, the current density on the surface of the cathode 1 becomes uniform, and the electron beam emitted from the emission surface 1a of the cathode 1 in the normal direction goes straight. It was decided by performing a computer simulation under the two conditions of indicating a trajectory. As a result, the radius of curvature r3 of the spherical surface portion 3a of the Wehnelt 3 is 4.5 mm, the diameter of the opening portion 3c is 5 mm, and the potential of the anode 2 is +2 than that of the cathode 1.
When the voltage was higher than 00V, the voltage applied to the Wehnelt 3 was + 200V higher than that of the cathode 1.
【００１９】更に、本例のアノード２の球面部２ａの曲
率半径ｒ２は１０ｍｍ、開口部２ｃの直径Ｄ２は３．５
ｍｍであるため、その開口部２ｃがカソード１の放出面
１ａの曲率中心を見込む角度（カソード角）２・θは、
次のように約２０°、即ち約３５０ｍｒａｄとなる。Further, the radius of curvature r2 of the spherical surface portion 2a of the anode 2 of this example is 10 mm, and the diameter D2 of the opening portion 2c is 3.5.
Therefore, the angle (cathode angle) 2 · θ at which the opening 2c looks at the center of curvature of the emission surface 1a of the cathode 1 is
It becomes about 20 °, that is, about 350 mrad as follows.
【００２０】 ２・θ＝２・sin-1{Ｄ２／（２・ｒ２）｝ ≒２０．１６° （２） 従って、本例によれば、クロスオーバの開口半角αｇは
原理的には１７５ｍｒａｄ程度まで可能であるが、上述
のウェーネルト３を使用した場合の開口半角αｇの実測
値は４５ｍｒａｄであり、クロスオーバの直径ｄｇは１
１μｍであった。その結果、エミッタンスの値は次のよ
うに９９０μｍ・ｍｒａｄとなった。2 · θ = 2 · sin −1 {D2 / (2 · r2)} ≈20.16 ° (2) Therefore, according to this example, the opening half angle αg of the crossover is theoretically about 175 mrad. However, the actual measurement value of the opening half angle αg when the above-mentioned Wehnelt 3 is used is 45 mrad, and the diameter dg of the crossover is 1.
It was 1 μm. As a result, the emittance value was 990 μm · mrad as follows.
【００２１】 エミッタンス＝１１×９０＝９９０（μｍ・ｍｒａｄ） （３） これによって、本例の電子銃では、従来の通常の電子銃
と比べて５０倍程度のエミッタンスが得られていること
が分かる。従って、広い視野を均一な強度分布の電子ビ
ームで照射することができる。また、例えばアノード２
の電位の制御によって、輝度は１×１０+3〜５×１０+4
Ａ／（ｃｍ2 ｓｒ）程度の低輝度の範囲で変えることが
できた。Emittance = 11 × 90 = 990 (μm · mrad) (3) From this, it can be seen that the electron gun of this example has about 50 times the emittance as compared with the conventional ordinary electron gun. . Therefore, a wide field of view can be irradiated with the electron beam having a uniform intensity distribution. Also, for example, the anode 2
The luminance is controlled to 1 × 10 +3 to 5 × 10 +4 by controlling the potential of
It could be changed within a low luminance range of about A / (cm 2 sr).
【００２２】なお、上述の例では、カソード１の放出面
１ａの曲率半径ｒ１は２ｍｍであるが、２ｍｍ以上とし
てもよい。また、ウェーネルト３の電位は、カソード１
の電位とアノード２の電位との間の電位であればよい。
次に、本例の電子銃１０を使用した分割転写方式の電子
線縮小転写装置の構成例につき図２を参照して説明す
る。Although the radius of curvature r1 of the emission surface 1a of the cathode 1 is 2 mm in the above example, it may be 2 mm or more. The potential of Wehnelt 3 is the same as that of the cathode 1.
It suffices if it is a potential between the potential of 1 and the potential of the anode 2.
Next, an example of the structure of a split transfer type electron beam reduction transfer apparatus using the electron gun 10 of this example will be described with reference to FIG.
【００２３】図２は本例の分割転写方式の電子線縮小転
写装置の概略構成を示し、この図２において、光軸ＡＸ
に平行にＺ軸を取り、Ｚ軸に垂直な平面内で図２の紙面
に垂直にＸ軸を、図２の紙面に平行にＹ軸を取って説明
する。図２において、図１の例と同じ構成の電子銃１０
から放出された電子ビームＥＢは、カバー７の開口部を
通過した後、コンデンサレンズ１１で平行ビームとさ
れ、視野選択偏向器１２によりＸＹ平面内で偏向されて
マスクＭ上の多数の副視野内の１つに導かれる。この際
に、マスクＭのパターン領域は、Ｘ方向に多数の主視野
に分割され、各主視野はそれぞれＹ方向に多数の副視野
に分割されている。FIG. 2 shows a schematic structure of a split transfer type electron beam reduction transfer apparatus of this example. In FIG. 2, an optical axis AX is shown.
In the following description, the Z axis is taken parallel to, the X axis is taken perpendicularly to the plane of FIG. 2 in the plane perpendicular to the Z axis, and the Y axis is taken parallel to the plane of FIG. In FIG. 2, an electron gun 10 having the same configuration as the example of FIG.
After passing through the opening of the cover 7, the electron beam EB emitted from the electron beam EB is collimated into a parallel beam by the condenser lens 11 and is deflected in the XY plane by the field-of-view selection deflector 12 to be in a number of sub-fields on the mask M. Is led to one of. At this time, the pattern area of the mask M is divided into a large number of main visual fields in the X direction, and each main visual field is divided into a large number of sub visual fields in the Y direction.
【００２４】マスクＭの１つの副視野を通過した電子ビ
ームＥＢは偏向器１３により所定量偏向された上で、投
影レンズ１４により集束されてクロスオーバ１７を形成
する。そして、クロスオーバ１７からの電子ビームＥＢ
は、対物レンズ１５によって電子線レジストが塗布され
たウエハＷ上の所定位置に所定の縮小率（例えば１／
４）で、その副視野のパターンを反転して結像する。マ
スクＭは、Ｘ軸方向に連続移動し、Ｙ軸方向にステップ
移動するステージ（不図示）上に保持されている。一
方、ウエハＷはＸ軸方向に移動自在なステージ（不図
示）上に保持されている。転写時には、例えばマスクＭ
を＋Ｘ方向に走査するのと同期して、ウエハＷを−Ｘ方
向に走査することにより、ウエハＷ上の１つの転写領域
への転写が行われる。走査方向が逆であるのは、レンズ
１４，１５によりパターン像が反転して転写されるから
である。The electron beam EB passing through one sub-field of the mask M is deflected by a predetermined amount by a deflector 13 and then focused by a projection lens 14 to form a crossover 17. Then, the electron beam EB from the crossover 17
Is a predetermined reduction ratio (for example, 1 /) at a predetermined position on the wafer W coated with the electron beam resist by the objective lens 15.
In 4), the pattern of the sub-field of view is inverted to form an image. The mask M is held on a stage (not shown) that continuously moves in the X-axis direction and steps in the Y-axis direction. On the other hand, the wafer W is held on a stage (not shown) movable in the X-axis direction. At the time of transfer, for example, the mask M
The wafer W is scanned in the -X direction in synchronism with the scanning in the + X direction, whereby the transfer to one transfer area on the wafer W is performed. The scanning direction is opposite because the pattern images are inverted and transferred by the lenses 14 and 15.
【００２５】この際に、本例の電子銃１０はエミッタン
スが大きいため、マスクＭ上の１つの副転写領域を大き
くできる。そのため、マスクＭのパターンを高いスルー
プットでウエハＷ上の各転写領域に転写することができ
る。なお、本発明は上述の実施の形態に限定されず、本
発明の要旨を逸脱しない範囲で種々の構成を取り得るこ
とは勿論である。At this time, since the electron gun 10 of this embodiment has a large emittance, one sub-transfer region on the mask M can be enlarged. Therefore, the pattern of the mask M can be transferred to each transfer region on the wafer W with high throughput. It should be noted that the present invention is not limited to the above-described embodiment, and can take various configurations without departing from the spirit of the present invention.
【００２６】[0026]
【発明の効果】本発明によれば、カソードの電子線の放
出面とアノードの対向面とが同心の球面に加工されてい
るため、カソードとアノードとの間に形成される同心の
等ポテンシャル面に垂直に安定に電子線が放出され、大
きな開口半角が得られる。従って、エミッタンスを大き
くすることができ、広い視野に均一な強度分布の電子線
を照射できると共に、動作が安定である利点がある。According to the present invention, since the electron beam emitting surface of the cathode and the facing surface of the anode are processed into concentric spherical surfaces, the concentric equipotential surface formed between the cathode and the anode. A stable electron beam is emitted perpendicularly to, and a large half-angle of opening can be obtained. Therefore, it is possible to increase the emittance, irradiate a wide field of view with an electron beam having a uniform intensity distribution, and there is an advantage that the operation is stable.
【００２７】また、カソードの電子線の放出面の曲率半
径を２ｍｍ以上としたときには、カソード表面の電界強
度が極端に大きくなることが避けられ、例えば１×１０
+2〜１×１０+4Ａ／（ｃｍ2 ｓｒ）程度の低輝度の電子
銃が得られる。また、アノードに印加される電圧を可変
として、そのアノードに印加される電圧を変化させるこ
とによって電子銃としての特性を制御する場合には、他
に制御用の電極を設けることなく簡単な機構で電子銃と
しての特性を制御できる。When the radius of curvature of the electron beam emitting surface of the cathode is set to 2 mm or more, it is possible to avoid the electric field strength on the cathode surface from becoming extremely large, for example, 1 × 10.
An electron gun with a low brightness of about +2 to 1 × 10 +4 A / (cm 2 sr) can be obtained. When the characteristics of the electron gun are controlled by changing the voltage applied to the anode and changing the voltage applied to the anode, a simple mechanism is provided without providing any other control electrode. The characteristics as an electron gun can be controlled.
【００２８】更に、カソードとアノードとの間にそのカ
ソードとそのアノードとの中間の電位の第３の電極を配
置したときには、この第３の電極によって電子線の開口
半角、ひいてはエミッタンスを或る程度制御できる利点
がある。Furthermore, when a third electrode having an intermediate potential between the cathode and the anode is arranged between the cathode and the anode, the half-angle of the opening of the electron beam, and thus the emittance, is made to some extent by the third electrode. It has the advantage of being controllable.
【図１】本発明による電子銃の実施の形態の一例を示す
一部の部材を断面に沿う端面図で表した構成図である。FIG. 1 is a configuration diagram showing an end view of a part of members showing an example of an embodiment of an electron gun according to the present invention along a cross section.
【図２】図１の電子銃を備えた分割転写方式の電子線縮
小転写装置の一例を示す概略構成図である。FIG. 2 is a schematic configuration diagram showing an example of a division transfer type electron beam reduction transfer apparatus including the electron gun of FIG.
【図３】電子銃の特性であるエミッタンスの説明図であ
る。FIG. 3 is an explanatory diagram of emittance, which is a characteristic of an electron gun.
１ カソード ２ アノード ３ ウェーネルト ４Ａ，４Ｂ 加熱用グラファイト ５Ａ，５Ｂ 電極 ７ カバー １０ 電子銃 1 cathode 2 anode 3 Wehnelt 4A, 4B heating graphite 5A, 5B electrode 7 cover 10 electron gun
Claims (4)
カソードと、 該カソードに対向するように配置された部分の内面が前
記電子線の放出面と同心の球面に形成されたアノード
と、を有することを特徴とする電子銃。1. A cathode in which an electron beam emission surface is formed into a convex spherical surface, and an anode in which an inner surface of a portion arranged to face the cathode is formed in a spherical surface concentric with the electron beam emission surface. And an electron gun.
率半径は２ｍｍ以上であることを特徴とする請求項１記
載の電子銃。2. The electron gun according to claim 1, wherein the radius of curvature of the electron beam emitting surface of the cathode is 2 mm or more.
あり、前記アノードに印加される電圧を変化させること
によって電子銃としての特性を制御することを特徴とす
る請求項１又は２記載の電子銃。3. The electron according to claim 1, wherein the voltage applied to the anode is variable, and the characteristic as an electron gun is controlled by changing the voltage applied to the anode. gun.
記カソードと前記アノードとの中間の電位の第３の電極
が配置されたことを特徴とする請求項１、２、又は３記
載の電子銃。4. The electron gun according to claim 1, 2 or 3, wherein a third electrode having an intermediate potential between the cathode and the anode is arranged between the cathode and the anode. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7287113A JPH09129166A (en) | 1995-11-06 | 1995-11-06 | Electron gun |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7287113A JPH09129166A (en) | 1995-11-06 | 1995-11-06 | Electron gun |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09129166A true JPH09129166A (en) | 1997-05-16 |
Family
ID=17713237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7287113A Withdrawn JPH09129166A (en) | 1995-11-06 | 1995-11-06 | Electron gun |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09129166A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1052678A2 (en) * | 1999-05-07 | 2000-11-15 | Lucent Technologies Inc. | Electron guns for lithography tools |
| FR2830680A1 (en) * | 2001-10-08 | 2003-04-11 | Thomson Licensing Sa | Electron gun tube micro emission cathode having cold emission micro emitter network with micro beam gun converger converging micro electron beam virtual zone opposite focussing electrode. |
| EP1308979A1 (en) * | 2000-05-16 | 2003-05-07 | Denki Kagaku Kogyo Kabushiki Kaisha | Electron gun and a method for using the same |
| FR2833750A1 (en) * | 2001-12-19 | 2003-06-20 | Thomson Licensing Sa | Cathode ray tube electron gun having cold cathode emission network transmitting electron beam assembly and mechanism zone converging micro beams two points. |
| EP1471561A2 (en) | 2003-04-21 | 2004-10-27 | Canon Kabushiki Kaisha | Electron gun |
| US6992307B2 (en) | 2003-06-26 | 2006-01-31 | Canon Kabushiki Kaisha | Electron beam source and electron beam exposure apparatus employing the electron beam source |
-
1995
- 1995-11-06 JP JP7287113A patent/JPH09129166A/en not_active Withdrawn
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1052678A2 (en) * | 1999-05-07 | 2000-11-15 | Lucent Technologies Inc. | Electron guns for lithography tools |
| EP1052678A3 (en) * | 1999-05-07 | 2006-07-05 | Lucent Technologies Inc. | Electron guns for lithography tools |
| KR100850034B1 (en) * | 1999-05-07 | 2008-08-04 | 루센트 테크놀러지스 인크 | Electron emitters for lithography tools |
| EP1308979A1 (en) * | 2000-05-16 | 2003-05-07 | Denki Kagaku Kogyo Kabushiki Kaisha | Electron gun and a method for using the same |
| FR2830680A1 (en) * | 2001-10-08 | 2003-04-11 | Thomson Licensing Sa | Electron gun tube micro emission cathode having cold emission micro emitter network with micro beam gun converger converging micro electron beam virtual zone opposite focussing electrode. |
| FR2833750A1 (en) * | 2001-12-19 | 2003-06-20 | Thomson Licensing Sa | Cathode ray tube electron gun having cold cathode emission network transmitting electron beam assembly and mechanism zone converging micro beams two points. |
| WO2004049380A3 (en) * | 2001-12-19 | 2004-07-22 | Thomson Licensing Sa | Electron gun for cathode ray tubes |
| EP1471561A2 (en) | 2003-04-21 | 2004-10-27 | Canon Kabushiki Kaisha | Electron gun |
| EP1471561A3 (en) * | 2003-04-21 | 2007-10-10 | Canon Kabushiki Kaisha | Electron gun |
| US6992307B2 (en) | 2003-06-26 | 2006-01-31 | Canon Kabushiki Kaisha | Electron beam source and electron beam exposure apparatus employing the electron beam source |
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