JP3956680B2 - Exposure method, exposure apparatus, and semiconductor device manufacturing method - Google Patents

Description

【００３５】
表１に示すエネルギーフィルターは電子顕微鏡や２次イオン質量分析器などに広く用いられているものであり、多くのバリエーションがある。また、表１で挙げた以外にもエネルギーを選別する光学系は数多くある。これらのエネルギーフィルターを露光に用いると、露光される荷電粒子の量（電流量）が減少し、スループットが低下する可能性がある。
【００３６】
しかしながら、すべてのパターンの露光にこのようなエネルギーフィルターを用いる必要はなく、極めて微細なパターンを露光する必要があるときのみ、スペクトロ・リソグラフィーを行えば、スループットを大幅に低下させることなく、解像度を飛躍的に向上させることができる。
【００３７】
一例として、表１で挙げたエネルギーフィルターのうち、Ω型エネルギーフィルター（Ωフィルター）を用いる場合について説明する。図２はΩフィルターの概略図である。図２に示すように、Ωフィルター１１は４個のセクター型電磁石１２ａ〜１２ｄを有する。セクター型電磁石１２ｂとセクター型電磁石１２ｃとの間には対称面１３が存在する。
【００３８】
入射絞り面（エントランスアパーチャー）１４に入射した電子ビームは、セクター型電磁石１２ａ〜１２ｄによって、エネルギー選択スリット１５に至るまでの軌道がΩ字状に偏向する。Ωフィルター１１によれば、電子のエネルギーの違いに応じて、電子ビームの軌道を分離させることができる。これにより、特定のエネルギーを持つ電子を選別できる。
【００３９】
図３は図２のΩフィルターを用いた露光方法を示す概略図である。図３に示すように、マスク３を透過した電子ビームＢは、対物・中間レンズ４ａを通過してビーム方向が制御され、エントランスアパーチャー１４に入射する。対物・中間レンズ４ａは図１のマスク後段光学系４に対応する。図示しないが、マスク３の前段には図１と同様にマスク前段光学系２が設けられる。
【００４０】
マスク３で散乱された電子のうち、進行方向を電子ビームＢの方向から大きく変えた電子は、対物・中間レンズ４ａによって電子ビームＢと同じ位置に結像されず、エントランスアパーチャー１４を通過しない。すなわち、マスク３での散乱により大きく方向を変えた電子は、対物・中間レンズ４ａとエントランスアパーチャー１４によって電子ビームＢから排除される。
【００４１】
エントランスアパーチャー１４を通過した電子ビームＢは、Ωフィルター１１を通過する。Ωフィルター１１を通過した電子は、エネルギーに応じてエネルギー選択スリット１５のスリット面上に分散し、特定のエネルギーを持つ電子のみがエネルギー選択スリット１５を通過する。したがって、エネルギー選択スリット１５の後段で行われるウェハの露光には、マスク３で散乱されずにマスク３を透過した電子のみが寄与する。
【００４２】
上記の本実施形態の露光方法および露光装置によれば、特定のエネルギーを持つ電子のみをウェハに入射させることができるため、対物・中間レンズ４ａの色収差が小さくなる。これにより、露光の解像度が向上し、マスクパターンを正確にウェハに転写することが可能となる。
【００４３】
図示しないが、上記の本実施形態において、Ωフィルターを表１に示す他のエネルギーフィルターに変更してもよい。Castaing型フィルターは、磁気プリズムの作用により、エネルギーの異なる電子ビームを分散させ、特定のエネルギーをもつ電子ビームのみをスリットにより選別する。
ウィーンフィルターは、フィルター内部の電場と磁場が直交する場を電子ビームが通過すると、エネルギーの異なる電子の軌道がずれることを利用して、電子のエネルギー選別を行うものである。
【００４４】
四重極質量フィルターは、四重極電極に直流と高周波交流を重ね合わせた電圧を印加して、四重極電極内を通過するイオンの選別を行うものである。四重極電極に入ったイオンは高周波電場の影響を受け、振動しながら電極内を進行する。印加電圧と電流の周波数に応じて、特定のイオンのみ振幅が増大せずに安定に振動して電極間を通過する。これにより、イオンは選別されて四重極質量フィルターから出射する。
【００４５】
本実施形態の半導体装置の製造方法は、ウェハ表面に塗布されたレジストに、上記の露光方法で露光を行い、パターンを転写する工程を含む。本実施形態の半導体装置の製造方法によれば、従来よりも微細化されたパターンをレジストに高精度に転写できる。したがって、半導体装置をさらに高集積化できる。
【００４６】
（実施形態２）
本実施形態の露光方法によれば、マスク透過後の荷電粒子をセクター型アナライザーで偏向させ、エネルギー選別する。この方法は、荷電ビーム露光に用いられた例はないが、光電子分光や２次イオン質量分析等の分光分析法においては広く用いられている。荷電粒子とエネルギーアナライザーとの主要な組み合わせを、表２に示す（前述の「マイクロビームアナリシス」(1985)参照）。
【００４７】
【表２】

【００４８】
荷電粒子が電子の場合とイオンの場合のいずれも、静電型または磁場型のセクターアナライザーを組み合わせることが可能である。アナライザーの形状は特に限定されず、例えば半球型やトロイダル型のアナライザーを用いることができる。
【００４９】
表２で挙げたアナライザーのうち、静電半球型アナライザーを用いる場合について、図面を参照して説明する。図４に示すように、マスク３を透過した電子ビームは、入射レンズ系２１によりアナライザー２２の入口に導かれる。アナライザー２２は内球と外球の半径および電圧差で定まる特定のエネルギー（パスエネルギー）を持つ電子のみを通過させる。
【００５０】
したがって、アナライザー２２の出口で電子ビームは単色化されている。これを出射レンズ系２３でウェハ２４上に結像する。例えば、パスエネルギーをマスク３に入射する電子のエネルギーに設定すれば、マスク３で散乱されずにマスク３を透過した電子のみが、ウェハ２４へのパターン転写に寄与することになる。
【００５１】
本実施形態の半導体装置の製造方法は、ウェハ表面に塗布されたレジストに、上記の露光方法で露光を行い、パターンを転写する工程を含む。本実施形態の半導体装置の製造方法によれば、従来よりも微細化されたパターンをレジストに高精度に転写できる。したがって、半導体装置をさらに高集積化できる。
【００５２】
（実施形態３）
本実施形態の露光方法によれば、マスク透過後の荷電粒子を減速電界法によりエネルギー選別する。この方法によれば、板状またはメッシュ状の電極を配置することにより、荷電粒子ビームの径路上に荷電粒子の阻止電場を形成する。これにより、特定のエネルギー以下の荷電粒子がウェハに入射するのを抑制できる。本実施形態の方法は、実施形態１および２の方法に比較するとエネルギー分解能は劣るが、エネルギー選別を行わない従来の露光に比較すれば、パターンの解像度を向上させることができる。
【００５３】
（実施形態４）
実施形態１〜３においては、マスクで散乱されずにマスクを透過した荷電粒子を選別し、ウェハの露光に用いる。それに対し、本実施形態においては、マスクで荷電粒子が散乱される際のエネルギー損失を利用して、荷電粒子のエネルギー選別を行う。
【００５４】
図５は本実施形態のマスクの平面図である。本実施形態のマスクは電子ビームが入射するマスクの例である。図５に示すように、基材３１の一部にパターン部３２が形成されている。基材３１は電子ビームが透過する厚さの薄膜であり、パターン部３２は基材３１を貫通するように設けられる。パターン部３２は周囲の基材３１によって支持されている。パターン部３２も電子ビームが透過する厚さで形成される。
【００５５】
パターン部３２は第１の相補パターン部３３、第２の相補パターン部３４および非分割パターン部３５を含む。パターン部３２の形状や分布によっては、必ずしもこのように３種類のパターン部３３〜３５を形成する必要はなく、パターン部を２種類以下としてもよい。あるいは、必要に応じて４種類以上のパターン部を形成してもよい。後述するように、複数の種類のパターン部を設けた場合、露光装置に取り付けたマスクを交換せずに、異なるパターンの多重露光を行うことができる。
【００５６】
本実施形態のマスクは基材３１、第１の相補パターン部３３、第２の相補パターン部３４および非分割パターン部３５が互いに異なる物質からなる。これらのパターン部３３〜３５のそれぞれには、基材３１に含まれず、かつ他のパターン部に含まれない少なくとも１種類の元素を含有させる。但し、これらのパターン部のうちの少なくとも一つと基材３１が同一の元素を含有しても、その元素の化学結合の状態が異なっていればよい。
【００５７】
例えば、第１の相補パターン部３３の材料がシリコン（Ｓｉ）で、基材３１の材料が酸化シリコン（ＳｉＯ₂ ）とすると、これらは同一の元素を含有するが、Ｓｉの化学結合の状態は異なる。したがって、第１の相補パターン部３３と基材３１における電子ビームのエネルギー損失は互いに異なる。これにより、電子ビームのエネルギー選別が可能となる。
【００５８】
従来の露光方法に用いられるステンシルマスクは、孔以外の部分で電子ビームを物理的に遮蔽する。それに対し、本実施形態のマスクは、パターン部と非パターン部での材料の化学的性質の違いを利用して、パターン部を透過する電子と非パターン部を透過する電子とをエネルギー選別する。このように基材と化学的性質の異なる材料でパターン部が形成されたマスクを、以下、化学マスクとも称する。
【００５９】
本実施形態の化学マスクに電子ビームが入射すると、基材３１および各パターン部３３〜３５にそれぞれ含有される元素によって、電子が散乱される。このとき、電子は衝突した元素あるいはその元素の化学結合の状態（化学的環境）に応じた固有のエネルギー損失を起こす。したがって、化学マスクを透過した電子ビームは、透過した部分の材料に応じて特有のエネルギー損失スペクトルを示す。
【００６０】
これらのエネルギー損失スペクトル間でのピーク位置のずれは、化学シフトと呼ばれる。原子核に特定のエネルギーの電磁波を照射すると、共鳴吸収が起こる。同種の原子核であっても、その周囲の化学的環境が異なった場合、共鳴吸収が起こるエネルギーは異なる。
【００６１】
これは主に、原子核の周辺に存在する電子や隣接する原子核によって小磁場が形成されることに起因する。化学シフトは、原子核の周囲の電子雲の密度だけでなく、例えば電子雲の球対称からのずれによる常磁性電流等、多様な因子の総和によって決定される。
【００６２】
材料に固有なエネルギー損失スペクトルを測定し、このスペクトルから材料に含有される元素を分析する方法は、電子エネルギー損失分光法（ＥＥＬＳ；electron energy loss spectroscopy)として広く知られている。図５の化学マスクの例では、各パターン部３３〜３５を透過した電子は、それぞれ異なるエネルギー分布を示す。
【００６３】
各パターン部３３〜３５のうち、特定のパターン部を含む領域を透過した電子ビームのエネルギー損失スペクトルには、他のパターン部または基材３１を透過した電子ビームのエネルギー損失スペクトルに現れない損失ピークが現れる。図３あるいは図４に示したスペクトロ・リソグラフィー装置で、パスエネルギーをそのような損失ピークのエネルギーに設定する。これにより、化学マスクのうちの特定のパターン部を透過した電子のみをエネルギー選別できる。したがって、単色化された電子を用いて高精度にパターン転写を行うことができる。
【００６４】
本実施形態の化学マスクによれば、スペクトロ・リソグラフィー装置に取り付けられたマスクを交換せずに、異なるパターンをウェハに多重露光することも可能である。例えば、図５に示す平行なライン状パターンを１枚のステンシルマスクに形成し、電子ビーム露光を行うと、パターン間隔が狭い場合には、孔を透過した電子が干渉し合い、パターンの解像度が低下することがある（近接効果）。
【００６５】
あるいは、ステンシルマスクの場合には、メンブレンのすべての部分が連続している必要があるために、例えばドーナツ状パターンのように１枚のマスクでは形成できないパターンがある。また、パターンの形状によっては、孔の形状に異方性の歪みが生じたり、メンブレンが破損しやすくなったりする。
【００６６】
このような場合、パターンを分割して２枚の相補マスクに振り分け、多重露光により相補的にパターンを転写する（例えば、U. Behringer and H. Engelke, J. Vac. Sci. Technol. B 11, 2400 (1993)）。これらの相補パターンを転写するには、露光装置での相補マスクの交換が必要となる。
【００６７】
一方、本実施形態の化学マスクによれば、図５に示すように、間隔の狭いパターンを第１の相補パターン部３３と第２の相補パターン部３４に分割し、それぞれのパターン部を異なる材料で形成する。一方のパターン部で特徴的な損失ピークが現れるように、第１の電子ビーム露光を行ってから、他方のパターン部で特徴的な損失ピークが現れるように、第２の電子ビーム露光を行う。したがって、マスクを交換せずに多重露光を行うことができる。
【００６８】
また、本実施形態の化学マスクによれば、メンブレンに孔を形成する場合と異なり、パターン部分が基材３１と異なる材料で埋め込まれる。したがって、パターン間隔が狭い場合にも、メンブレンの機械的強度が低下しにくく、パターンの位置ずれや歪みが抑制される。さらに、ステンシルマスクではパターンの分割が不可欠であるような形状のパターンであっても、１枚のマスクに形成することが可能となる。
【００６９】
本実施形態の半導体装置の製造方法は、ウェハ表面に塗布されたレジストに、上記の露光方法で露光を行い、パターンを転写する工程を含む。化学マスクに何種類のパターン部が形成されるかに関わらず、各パターン部に特徴的な損失ピークのエネルギーを持つ電子ビームが単色化される。したがって、本実施形態の半導体装置の製造方法によれば、従来よりも微細化されたパターンをレジストに高精度に転写でき、半導体装置をさらに高集積化できる。
【００７０】
（実施形態５）
本実施形態によれば、実施形態４の化学マスクに電子ビームではなくＸ線を照射して、パターン部３２から材料に応じた光電子を発生させる。発生した光電子を、例えば図４に示した偏向エネルギーアナライザーによりエネルギー選別する。偏向エネルギーアナライザーにより単色化された電子ビームを露光に用いることにより、パターンの解像度を向上させることができる。
【００７１】
本実施形態においても、実施形態４と同様に、化学マスクに形成されるパターン部３２は３種類に限定されない。ここでは、説明を容易とするため、図５に示すように３種類のパターン部３３〜３５が形成された化学マスクを用いることとする。
【００７２】
化学マスクにＸ線を照射すると、基材３１および各パターン部３３〜３５に含有される元素に固有なエネルギーを持った光電子が放出される。すなわち、基材３１および各パターン部３３〜３５から放出される光電子は、それぞれ異なるエネルギー分布を持つ。このような光電子をエネルギー分析すれば、含有されている元素を判別できる。これは光電子分光法（ＰＥＳ；photoelectron spectroscopy）として広く知られている。
【００７３】
本実施形態の露光方法によれば、図４に示す偏向エネルギーアナライザーを有するスペクトロ・リソグラフィー装置を用いる。偏向エネルギーアナライザーのアナライザー２２に印加する電圧を調整し、パスエネルギーを特定のパターン部から放出される光電子のエネルギーに設定しておく。
【００７４】
スペクトロ・リソグラフィー装置において、図５に示す化学マスクにＸ線を照射して、光電子を放出させる。放出された光電子は、偏向エネルギーアナライザーの入射レンズ系２１に取り込まれ、単色化された電子ビームが出射レンズ系２３から出射する。単色化された電子ビームによりウェハ２４が露光される。
【００７５】
本実施形態においても、相補パターンの多重露光を行うことができる。例えば、図５の第１の相補パターン部３３で光電子が発生するように、化学マスクに対して第１のＸ線照射を行ってから、第２の相補パターン部３４で光電子が発生するように、化学マスクに対して第２のＸ線照射を行う。これにより、スペクトロ・リソグラフィー装置に取り付けられた化学マスクを交換せずに、多重露光を行い、パターンを相補的に転写することができる。
【００７６】
上記の本実施形態の露光方法によれば、図４に示すように、化学マスクの一方の面にＸ線を照射して、他方の面から放出される光電子を偏向エネルギーアナライザーに入射させる。あるいは、図示しないが、化学マスクの一方の面にＸ線を照射して、その面から放出される光電子を偏向エネルギーアナライザーに入射させ、光電子のエネルギー選別を行うこともできる。
【００７７】
この構成は、電子ビームがマスクを透過しない点で、前述した特許第２９５７６６９号公報記載の反射マスクおよび特開２０００−１８２９４３号公報記載の２次電子を放出するマスクと共通する。しかしながら、これらの公報に記載されたマスクには荷電粒子ビームが照射されるのに対し、本実施形態の化学マスクにはＸ線が照射され、これにより光電子が放出される。したがって、上記の公報に記載された従来のマスクと本実施形態の化学マスクとは本質的に異なる。
【００７８】
本実施形態の半導体装置の製造方法は、ウェハ表面に塗布されたレジストに、上記の露光方法で露光を行い、パターンを転写する工程を含む。化学マスクに何種類のパターン部が形成されるかに関わらず、各パターン部で固有のエネルギーを持つ光電子を発生させる。
したがって、本実施形態の半導体装置の製造方法によれば、従来よりも微細化されたパターンをレジストに高精度に転写でき、半導体装置をさらに高集積化できる。
【００７９】
本発明の露光方法、露光装置、半導体装置の製造方法およびマスクの実施形態は、上記の説明に限定されない。例えば、実施形態５のスペクトロ・リソグラフィー装置において、図４に示すような電子光学系を採用するかわりに、光電子顕微鏡（ＰＥＥＭ；photoelectron energy microscope)に用いられるような拡大結像レンズ系を採用することも可能である。その他、本発明の要旨を逸脱しない範囲で、種々の変更が可能である。
【００８０】
【発明の効果】
本発明の露光方法および露光装置によれば、マスクを透過したビームの単色性が改善され、パターンの解像度が向上する。本発明の半導体装置の製造方法によれば、微細パターンを高精度に転写できるため、半導体装置を高集積化できる。本発明のマスクによれば、リソグラフィー工程において微細パターンを高精度に転写することが可能となる。
【図面の簡単な説明】
【図１】図１は本発明の露光方法の原理を示す概略図である。
【図２】図２は本発明の実施形態１に係る露光装置の一部を示す概略図である。
【図３】図３は本発明の実施形態１に係る露光装置の一部を示す概略図である。
【図４】図４は本発明の実施形態２に係る露光装置の一部を示す概略図である。
【図５】図５は本発明の実施形態４および５に係るマスクの平面図である。
【図６】図６は従来の露光方法の原理を示す概略図である。
【符号の説明】
１、１０１…荷電粒子線源、２、１０２…マスク前段光学系、３、１０３…マスク、４、１０４…マスク後段光学系、４ａ…対物・中間レンズ、５…分光系、６、１０５…像面、１１…Ωフィルター、１２ａ〜１２ｄ…セクター型電磁石、１３…対称面、１４…エントランスアパーチャー、１５…エネルギー選択スリット、２１…入射レンズ系、２２…アナライザー、２３…出射レンズ系、２４…ウェハ、３１…基材、３２…パターン部、３３…第１の相補パターン部、３４…第２の相補パターン部、３５…非分割パターン部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure method, an exposure apparatus, a method for manufacturing a semiconductor device, and a mask used for them.
[0002]
[Prior art]
In lithography using a charged particle beam such as an electron beam or an ion beam, exposure is performed through a mask on which a pattern is directly formed and a pattern is directly drawn on a wafer by scanning the beam. There are projection types that transfer to a wafer. The latter is superior in throughput (Takikawa et al. “Innovation of ULSI Lithography Technology” (Science Forum (1994))).
[0003]
Masks used in projection lithography include stencil masks (HC Pfeiffer, Jpn. J. Appl. Phys. 34, 6658 (1995)) in which the pattern part is a hole, and heavy metal in parts other than the pattern. There is a scattering mask (LR Harriott, J. Vac. Sci. Technol B 15, 2130 (1997)) in which a thin film is formed.
[0004]
FIG. 6 is a schematic view showing the principle of a conventional exposure method, and shows a part of a projection exposure apparatus using charged particles such as ions and electrons. As shown in FIG. 6, charged particles are emitted from the charged particle beam source 101, the beam B is collimated or focused by the mask pre-stage optical system 102, and the mask 103 is exposed.
[0005]
In FIG. 6, the mask pre-stage optical system 102 is illustrated as a single optical lens for general description. However, in actuality, as in the case of a single or a plurality of electrostatic lenses or magnetic lenses, charging is performed. A particle that has a lens effect is used. Similarly, the mask post-stage optical system 104 is illustrated as a single optical lens for simplification, but is not limited to a single optical lens.
[0006]
6 shows a stencil mask having holes 103a in a predetermined pattern as the mask 103, a scattering mask may be used instead of the stencil mask. The beam B incident on the mask 103 is transmitted through the hole 103a, and is imaged on the image plane 105 by the post mask optical system 104 as indicated by the solid line a. The image plane 105 corresponds to the wafer surface. The mask pattern is transferred onto the wafer according to the transfer principle described above. Therefore, ideally, a pattern that accurately reflects the mask pattern (pattern as shown by hatching in FIG. 6) is transferred to the image plane 105.
[0007]
Alternatively, Japanese Patent No. 2957669 discloses a reflection mask on which a reflection pattern for reflecting a charged beam is formed and a charged beam exposure apparatus using the same. Furthermore, Japanese Patent Application Laid-Open No. 2000-182943 discloses a mask having a surface on which a desired pattern is formed of a material having different secondary electron emission efficiency, and a charged beam exposure apparatus and a charged beam exposure method using the mask. ing. As described in these publications, lithography can be performed using a mask through which a charged beam does not pass.
[0008]
[Problems to be solved by the invention]
However, according to the above conventional masks, charged particles are scattered by the mask when the charged particle beam passes through the mask. This not only changes the energy and direction of the beam, but the excited secondary particles are emitted from the mask, reducing the monochromaticity and parallelism of the beam incident on the wafer (M. Kotera et al., Jpn J. Appl. Phys. 39, 6861 (2000)).
[0009]
For example, in the reduced projection system shown in FIG. 6, as shown in the Monte Carlo simulation (M. Kotera et al., Jpn. J. Appl. Phys. 39, 6861 (2000)), the charge incident on the mask. The particles are scattered by the mask, the energy and the traveling direction are changed, and secondary particles are generated. The post mask optical system 104 is optimized for imaging a charged particle beam having the same energy as the beam incident on the mask 103.
[0010]
Therefore, the charged particles whose energy has been partially lost due to scattering in the mask enter the image plane 105 along a locus shown by a dotted line in FIG. 6 and deviate from the ideal locus shown by a solid line a. Due to such chromatic aberration, the pattern actually transferred to the wafer is blurred as shown by the solid line b, and the contrast and resolution of the pattern are lowered.
[0011]
Of the electron beam projection lithography, the proximity transfer method places the mask and the wafer close to each other, and the pattern on the mask is usually transferred to the wafer at the same magnification. Therefore, when the monochromaticity or parallelism of the beam transmitted through the mask is lowered, the resolution of the pattern is significantly lowered (T. Utsumi, J. Vac. Sci. Technol B 17, 2897 (1999)).
[0012]
Even in a reduction projection system, a reflection type, or a secondary electron emission type exposure system, the spread of beam energy causes chromatic aberration of the electron optical system, which limits the resolution limit of the pattern (Katsuaki Ura “Electron Optics” (Kyoritsu) Complete book (1979)).
The present invention has been made in view of the above problems, and therefore the present invention provides an exposure method, an exposure apparatus, a method for manufacturing a semiconductor device, and a mask capable of dramatically improving the resolution of a fine pattern. The purpose is to provide.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, an exposure method of the present invention includes a step of making a charged particle beam incident on a mask having a charged particle beam transmission portion formed in a predetermined pattern, and among charged particles transmitted through the mask, The method includes a step of selecting charged particles having a specific energy and a step of causing charged particles having the selected specific energy to enter a photosensitive surface.
[0014]
Alternatively, the exposure method of the present invention includes a thin film that transmits an electron beam, and a pattern portion that is formed in a part of the thin film so as to penetrate the thin film in a predetermined pattern and is made of a material different from the thin film. A step of allowing an electron beam having a predetermined energy to enter a mask having the mask, and selecting electrons having a peak energy appearing only in an electron energy loss spectrum of the electron beam transmitted through the pattern portion from among the electrons transmitted through the mask And a step of causing the selected electrons to enter the photosensitive surface.
[0015]
Alternatively, the exposure method of the present invention has a thin film and a pattern portion formed in a predetermined pattern on a part of the thin film and made of a substance different from the thin film, and is irradiated with X-rays having a predetermined energy. The step of making X-rays of a predetermined energy incident on a mask in which the energy of electrons generated in the thin film and the pattern part is different, and the electrons generated by irradiating the pattern part with X-rays are selected. And a step of causing the selected electrons to enter the photosensitive surface.
[0016]
In order to achieve the above object, an exposure apparatus of the present invention is an exposure apparatus that irradiates a photosensitive surface with a charged particle beam and transfers a pattern onto the photosensitive surface, and is a charged particle beam source that emits a charged particle beam. A mask on which the charged particle beam emitted from the charged particle beam source is incident, and a mask in which a charged particle beam transmitting portion is formed in the pattern, and among the charged particles transmitted through the mask, And energy sorting means for sorting charged particles having energy and making them enter the photosensitive surface.
[0017]
Alternatively, the exposure apparatus of the present invention is an exposure apparatus that irradiates a photosensitive surface with an electron beam and transfers a pattern onto the photosensitive surface. The exposure apparatus emits an electron beam, and is emitted from the electron beam source. A mask on which the electron beam is incident, a thin film that transmits the electron beam, and a pattern made of a material different from the thin film, formed in a predetermined pattern on a part of the thin film so as to penetrate the thin film The mask has different electron energy loss spectra obtained by transmitting an electron beam of a predetermined energy between the thin film and the pattern portion, and the pattern portion of the electron beam transmitted through the mask. The energy having the peak energy appearing in the electron energy loss spectrum of the electron beam transmitted through the screen is selected and made incident on the photosensitive surface. And having a chromatography selection means.
[0018]
Alternatively, the exposure apparatus of the present invention is an exposure apparatus that irradiates a photosensitive surface with an electron beam and transfers a pattern onto the photosensitive surface, and emits an X-ray from the X-ray source and the X-ray source. A mask on which the X-ray is incident, the mask having a thin film and a pattern portion formed in a predetermined pattern on a part of the thin film and made of a material different from the thin film, and irradiated with the X-ray The mask having different energy of electrons generated in the thin film and the pattern portion, and energy selecting means for selecting electrons generated by irradiating the pattern portion with X-rays and causing the electrons to enter the photosensitive surface. It is characterized by having.
[0019]
In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention includes a step of causing a charged particle beam to enter a mask having a charged particle beam transmission portion formed in a predetermined pattern, and a charged particle transmitted through the mask. Among these, the method includes a step of selecting charged particles having a specific energy, and a step of causing the charged particles having the selected specific energy to enter a resist and transferring the pattern to the resist.
[0020]
Alternatively, the method of manufacturing a semiconductor device according to the present invention includes a thin film that transmits an electron beam, and a pattern made of a material different from the thin film, which is formed in a part of the thin film so as to penetrate the thin film. A step of allowing an electron beam having a predetermined energy to enter a mask having a portion, and among the electrons transmitted through the mask, the electron beam transmitted through the thin film does not appear in the electron energy loss spectrum and transmitted through the pattern portion. The method includes a step of selecting an electron having a peak energy appearing in an electron energy loss spectrum of an electron beam, and a step of causing the selected electron to enter a resist and transferring the pattern to the resist.
[0021]
Alternatively, when the semiconductor device manufacturing method of the present invention has a thin film and a pattern portion formed in a predetermined pattern on a part of the thin film and made of a material different from the thin film, the X-ray is irradiated A step of causing X-rays of a predetermined energy to enter a mask in which energy of electrons generated in the thin film and the pattern portion is different, and a step of selecting electrons generated by irradiating the pattern portion with X-rays And a step of causing the selected electrons to enter the resist and transferring the pattern to the resist.
[0022]
In order to achieve the above object, a mask of the present invention comprises a thin film that transmits an electron beam, and a material different from the thin film formed in a predetermined pattern in a part of the thin film so as to penetrate the thin film. And an electron energy loss spectrum obtained by transmitting an electron beam having a predetermined energy is different between the thin film and the pattern portion.
[0023]
Alternatively, the mask of the present invention has a thin film and a pattern portion formed in a predetermined pattern on a part of the thin film and made of a material different from the thin film, and is irradiated with X-rays having a predetermined energy. The energy of generated electrons is different between the thin film and the pattern portion.
[0024]
This makes it possible to prevent charged particles that have been scattered by the mask and whose energy and locus have changed from entering the photosensitive surface (or resist). According to the exposure method, exposure apparatus, semiconductor device manufacturing method, and mask of the present invention, the monochromaticity and parallelism of the beam incident on the photosensitive surface can be improved, and the exposure resolution can be dramatically improved.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an exposure method, an exposure apparatus, a semiconductor device manufacturing method, and a mask according to the present invention will be described below with reference to the drawings. First, the basic principle of the exposure method of the present invention will be described in comparison with the conventional exposure method shown in FIG.
[0026]
FIG. 1 is a schematic view showing the principle of the exposure method of the present invention, and shows, for example, a part of a projection type exposure apparatus using charged particles such as ions and electrons. As shown in FIG. 1, charged particles are emitted from the charged particle beam source 1, and the beam B is monochromatic by the pre-mask optical system 2. Further, the beam B is collimated or focused by the pre-mask optical system 2 and the mask 3 is exposed.
[0027]
In FIG. 1, for the sake of generalization, the mask pre-stage optical system 2 is illustrated as a single optical lens. However, in actuality, as in the case of a single or a plurality of electrostatic lenses or magnetic lenses, charging is performed. A particle that has a lens effect is used. Similarly, the mask post-stage optical system 4 is illustrated as a single optical lens for simplification, but is not limited to a single optical lens.
[0028]
Moreover, although the stencil mask which has the hole 3a by the predetermined pattern was shown as the mask 3 in FIG. 1, a scattering mask may be sufficient instead of a stencil mask. The beam B incident on the mask 3 passes through the hole 3a and is focused by the post mask optical system 4 as shown by the solid line a.
[0029]
Since the post mask optical system 4 is optimized to form an image of a charged particle beam having the same energy as the beam incident on the mask 3, the secondary particles generated by the mask are ideal for the beam B indicated by the solid line a. Deviate from the trajectory. According to the exposure method of the present invention, the charged particles transmitted through the mask 3 and the secondary particles generated by the mask are focused by the post mask optical system 4 and enter the spectroscopic system 5.
[0030]
The charged particles are subjected to energy selection by the spectroscopic system 5, and only charged particles having specific energy (path energy) set by the spectroscopic system 5 are imaged on the image plane 6. Since the secondary particles generated in the mask have energy different from the path energy, they are excluded by the prism 5a and the diaphragm 5b of the spectroscopic system 5 and do not reach the image plane 6 as indicated by the dotted line. Therefore, a pattern (a pattern as shown by hatching in FIG. 1) that accurately reflects the mask pattern is transferred to the image plane 6.
[0031]
In FIG. 1, for the sake of simplicity, the spectroscopic system 5 is shown as a combination of a prism 5a and a diaphragm 5b. However, the spectroscopic system 5 is not limited to such a configuration, and various energy filters used for charged particles, An energy analyzer can be used. Details of such a spectroscopic system 5 will be described later.
[0032]
According to the exposure method and the exposure apparatus of the present invention, secondary particles or the like that do not have pass energy are eliminated by the spectroscopic system 5, so that the chromatic aberration of the post mask optical system 4 is reduced. Also, the resolution on the image plane 6 is improved. The exposure method including energy sorting as described above is hereinafter also referred to as spectro lithography.
[0033]
(Embodiment 1)
When an energy filter optical system is incorporated into a normal projection type charged particle beam exposure apparatus, the main combinations of charged particles and energy filters are as shown in Table 1 (edited by the Japan Society for the Promotion of Science, Microbeam Analysis No. 141 Committee, “ Microbeam Analysis "(Asakura Shoten (1985))).
[0034]
[Table 1]

[0035]
The energy filter shown in Table 1 is widely used in electron microscopes and secondary ion mass spectrometers, and has many variations. In addition to those listed in Table 1, there are many optical systems for selecting energy. When these energy filters are used for exposure, the amount of charged particles to be exposed (current amount) is reduced, and the throughput may be reduced.
[0036]
However, it is not necessary to use such an energy filter for exposure of all patterns. Spectrolithography can be used only when it is necessary to expose very fine patterns, and resolution can be reduced without significantly reducing throughput. It can be improved dramatically.
[0037]
As an example, the case where an Ω type energy filter (Ω filter) is used among the energy filters listed in Table 1 will be described. FIG. 2 is a schematic diagram of an Ω filter. As shown in FIG. 2, the Ω filter 11 has four sector type electromagnets 12a to 12d. A symmetry plane 13 exists between the sector type electromagnet 12b and the sector type electromagnet 12c.
[0038]
The electron beam that has entered the entrance diaphragm surface (entrance aperture) 14 is deflected in an Ω shape by the sector type electromagnets 12 a to 12 d until reaching the energy selection slit 15. According to the Ω filter 11, the trajectory of the electron beam can be separated according to the difference in electron energy. Thereby, electrons having specific energy can be selected.
[0039]
FIG. 3 is a schematic view showing an exposure method using the Ω filter of FIG. As shown in FIG. 3, the electron beam B that has passed through the mask 3 passes through the objective / intermediate lens 4 a, the direction of the beam is controlled, and enters the entrance aperture 14. The objective / intermediate lens 4a corresponds to the post mask optical system 4 of FIG. Although not shown, a mask pre-stage optical system 2 is provided in the front stage of the mask 3 as in FIG.
[0040]
Among the electrons scattered by the mask 3, electrons whose traveling direction is greatly changed from the direction of the electron beam B are not imaged at the same position as the electron beam B by the objective / intermediate lens 4 a and do not pass through the entrance aperture 14. That is, electrons whose direction has been greatly changed due to scattering by the mask 3 are excluded from the electron beam B by the objective / intermediate lens 4 a and the entrance aperture 14.
[0041]
The electron beam B that has passed through the entrance aperture 14 passes through the Ω filter 11. Electrons that have passed through the Ω filter 11 are dispersed on the slit surface of the energy selection slit 15 according to energy, and only electrons having specific energy pass through the energy selection slit 15. Therefore, only the electrons transmitted through the mask 3 without being scattered by the mask 3 contribute to the exposure of the wafer performed at the subsequent stage of the energy selection slit 15.
[0042]
According to the exposure method and the exposure apparatus of the present embodiment, since only electrons having specific energy can be incident on the wafer, the chromatic aberration of the objective / intermediate lens 4a is reduced. Thereby, the resolution of exposure is improved, and the mask pattern can be accurately transferred to the wafer.
[0043]
Although not shown, in the above-described embodiment, the Ω filter may be changed to another energy filter shown in Table 1. The castaing type filter disperses electron beams having different energies by the action of a magnetic prism, and selects only electron beams having a specific energy by slits.
The Wien filter performs electron energy selection by utilizing the fact that the trajectory of electrons having different energies shifts when an electron beam passes through a field in which the electric field and magnetic field inside the filter are orthogonal to each other.
[0044]
The quadrupole mass filter applies a voltage obtained by superimposing direct current and high frequency alternating current to the quadrupole electrode, and selects ions passing through the quadrupole electrode. Ions entering the quadrupole electrode are affected by the high-frequency electric field and travel in the electrode while vibrating. Depending on the frequency of the applied voltage and current, only specific ions do not increase in amplitude and vibrate stably and pass between the electrodes. As a result, ions are sorted and emitted from the quadrupole mass filter.
[0045]
The manufacturing method of the semiconductor device of this embodiment includes a step of transferring a pattern by exposing the resist applied to the wafer surface by the exposure method described above. According to the method for manufacturing a semiconductor device of the present embodiment, a finer pattern than before can be transferred to a resist with high accuracy. Therefore, the semiconductor device can be further highly integrated.
[0046]
(Embodiment 2)
According to the exposure method of the present embodiment, the charged particles after passing through the mask are deflected by the sector type analyzer, and energy selection is performed. Although this method has not been used for charged beam exposure, it is widely used in spectroscopic methods such as photoelectron spectroscopy and secondary ion mass spectrometry. The main combinations of charged particles and energy analyzers are shown in Table 2 (see the aforementioned “microbeam analysis” (1985)).
[0047]
[Table 2]

[0048]
In both cases where the charged particles are electrons and ions, it is possible to combine an electrostatic or magnetic sector analyzer. The shape of the analyzer is not particularly limited, and for example, a hemispherical or toroidal analyzer can be used.
[0049]
Of the analyzers listed in Table 2, the case of using an electrostatic hemispherical analyzer will be described with reference to the drawings. As shown in FIG. 4, the electron beam transmitted through the mask 3 is guided to the entrance of the analyzer 22 by the incident lens system 21. The analyzer 22 passes only electrons having specific energy (path energy) determined by the radius and voltage difference between the inner sphere and the outer sphere.
[0050]
Therefore, the electron beam is monochromatized at the outlet of the analyzer 22. This is imaged on the wafer 24 by the exit lens system 23. For example, if the pass energy is set to the energy of electrons incident on the mask 3, only the electrons that are transmitted through the mask 3 without being scattered by the mask 3 contribute to pattern transfer onto the wafer 24.
[0051]
The manufacturing method of the semiconductor device of this embodiment includes a step of transferring a pattern by exposing the resist applied to the wafer surface by the exposure method described above. According to the method for manufacturing a semiconductor device of the present embodiment, a finer pattern than before can be transferred to a resist with high accuracy. Therefore, the semiconductor device can be further highly integrated.
[0052]
(Embodiment 3)
According to the exposure method of this embodiment, the charged particles after passing through the mask are subjected to energy selection by the deceleration electric field method. According to this method, a blocking electric field of charged particles is formed on the path of the charged particle beam by arranging plate-like or mesh-like electrodes. Thereby, it can suppress that the charged particle below specific energy injects into a wafer. The method of this embodiment is inferior in energy resolution to the methods of Embodiments 1 and 2, but can improve the resolution of the pattern as compared to conventional exposure that does not perform energy selection.
[0053]
(Embodiment 4)
In the first to third embodiments, charged particles that are transmitted through the mask without being scattered by the mask are selected and used for wafer exposure. On the other hand, in the present embodiment, energy selection of charged particles is performed using energy loss when charged particles are scattered by a mask.
[0054]
FIG. 5 is a plan view of the mask of this embodiment. The mask of this embodiment is an example of a mask on which an electron beam is incident. As shown in FIG. 5, a pattern portion 32 is formed on a part of the base material 31. The base material 31 is a thin film having a thickness through which an electron beam is transmitted, and the pattern portion 32 is provided so as to penetrate the base material 31. The pattern portion 32 is supported by the surrounding base material 31. The pattern portion 32 is also formed with a thickness that allows the electron beam to pass therethrough.
[0055]
The pattern portion 32 includes a first complementary pattern portion 33, a second complementary pattern portion 34, and a non-divided pattern portion 35. Depending on the shape and distribution of the pattern portion 32, it is not always necessary to form the three types of pattern portions 33 to 35, and the number of pattern portions may be two or less. Or you may form four or more types of pattern parts as needed. As will be described later, when a plurality of types of pattern portions are provided, multiple exposures of different patterns can be performed without replacing the mask attached to the exposure apparatus.
[0056]
In the mask of the present embodiment, the base material 31, the first complementary pattern portion 33, the second complementary pattern portion 34, and the non-divided pattern portion 35 are made of different materials. Each of these pattern portions 33 to 35 contains at least one element that is not included in the base material 31 and is not included in the other pattern portions. However, even if at least one of these pattern portions and the base material 31 contain the same element, it is sufficient that the state of chemical bonding of the element is different.
[0057]
For example, the material of the first complementary pattern portion 33 is silicon (Si), and the material of the substrate 31 is silicon oxide (SiO ₂ ), These contain the same elements, but the state of chemical bonding of Si is different. Therefore, the energy loss of the electron beam in the first complementary pattern portion 33 and the substrate 31 is different from each other. Thereby, energy sorting of the electron beam becomes possible.
[0058]
The stencil mask used in the conventional exposure method physically shields the electron beam at a portion other than the hole. On the other hand, the mask of this embodiment uses the difference in the chemical properties of the material in the pattern portion and the non-pattern portion to select energy between electrons that pass through the pattern portion and electrons that pass through the non-pattern portion. A mask having a pattern portion formed of a material having a chemical property different from that of the base material is also referred to as a chemical mask hereinafter.
[0059]
When an electron beam is incident on the chemical mask of this embodiment, electrons are scattered by the elements contained in the substrate 31 and the pattern portions 33 to 35, respectively. At this time, the electrons cause an inherent energy loss depending on the colliding element or the chemical bond state (chemical environment) of the element. Therefore, the electron beam transmitted through the chemical mask exhibits a specific energy loss spectrum depending on the material of the transmitted portion.
[0060]
The shift in peak position between these energy loss spectra is called chemical shift. When an atomic nucleus is irradiated with electromagnetic waves of a specific energy, resonance absorption occurs. Even in the case of the same kind of nucleus, if the chemical environment around it is different, the energy at which resonance absorption occurs differs.
[0061]
This is mainly due to the formation of a small magnetic field by electrons existing around the nucleus and adjacent nuclei. The chemical shift is determined not only by the density of the electron cloud around the nucleus, but also by the sum of various factors such as the paramagnetic current due to the deviation of the electron cloud from the spherical symmetry.
[0062]
A method of measuring an energy loss spectrum specific to a material and analyzing elements contained in the material from this spectrum is widely known as electron energy loss spectroscopy (EELS). In the example of the chemical mask of FIG. 5, electrons transmitted through the pattern portions 33 to 35 show different energy distributions.
[0063]
The loss peak that does not appear in the energy loss spectrum of the electron beam transmitted through the other pattern unit or the base material 31 in the energy loss spectrum of the electron beam transmitted through the region including the specific pattern unit among the pattern units 33 to 35. Appears. With the spectrolithographic apparatus shown in FIG. 3 or FIG. 4, the path energy is set to such a loss peak energy. Thereby, only the electrons that have passed through the specific pattern portion of the chemical mask can be subjected to energy selection. Therefore, pattern transfer can be performed with high accuracy using monochromatized electrons.
[0064]
According to the chemical mask of this embodiment, it is possible to perform multiple exposure of different patterns on the wafer without replacing the mask attached to the spectrolithography apparatus. For example, when the parallel line pattern shown in FIG. 5 is formed on one stencil mask and electron beam exposure is performed, when the pattern interval is narrow, electrons transmitted through the holes interfere with each other and the pattern resolution is reduced. May decrease (proximity effect).
[0065]
Alternatively, in the case of a stencil mask, since all parts of the membrane need to be continuous, there are patterns that cannot be formed with a single mask, such as a donut-shaped pattern. Further, depending on the shape of the pattern, anisotropic distortion may occur in the shape of the hole, or the membrane may be easily damaged.
[0066]
In such a case, the pattern is divided and assigned to two complementary masks, and the pattern is transferred complementarily by multiple exposure (for example, U. Behringer and H. Engelke, J. Vac. Sci. Technol. B 11, 2400 (1993)). In order to transfer these complementary patterns, it is necessary to replace the complementary mask in the exposure apparatus.
[0067]
On the other hand, according to the chemical mask of the present embodiment, as shown in FIG. 5, a pattern having a narrow interval is divided into a first complementary pattern portion 33 and a second complementary pattern portion 34, and the respective pattern portions are made of different materials. Form with. After the first electron beam exposure is performed so that a characteristic loss peak appears in one pattern portion, the second electron beam exposure is performed so that a characteristic loss peak appears in the other pattern portion. Therefore, multiple exposure can be performed without exchanging the mask.
[0068]
In addition, according to the chemical mask of the present embodiment, the pattern portion is embedded with a material different from that of the base material 31, unlike the case of forming holes in the membrane. Therefore, even when the pattern interval is narrow, the mechanical strength of the membrane is not easily lowered, and pattern displacement and distortion are suppressed. Furthermore, even with a stencil mask, it is possible to form a pattern having a shape in which division of the pattern is indispensable on a single mask.
[0069]
The manufacturing method of the semiconductor device of this embodiment includes a step of transferring a pattern by exposing the resist applied to the wafer surface by the exposure method described above. Regardless of how many types of pattern portions are formed on the chemical mask, an electron beam having a characteristic loss peak energy in each pattern portion is monochromatized. Therefore, according to the method for manufacturing a semiconductor device of this embodiment, a pattern finer than the conventional one can be transferred to a resist with high accuracy, and the semiconductor device can be further highly integrated.
[0070]
(Embodiment 5)
According to the present embodiment, the chemical mask of the fourth embodiment is irradiated with X-rays instead of an electron beam, and photoelectrons corresponding to the material are generated from the pattern portion 32. The generated photoelectrons are subjected to energy selection using, for example, a deflection energy analyzer shown in FIG. The resolution of the pattern can be improved by using an electron beam monochromatized by the deflection energy analyzer for exposure.
[0071]
Also in this embodiment, the pattern part 32 formed in a chemical mask is not limited to three types similarly to Embodiment 4. FIG. Here, for ease of explanation, a chemical mask in which three types of pattern portions 33 to 35 are formed as shown in FIG. 5 is used.
[0072]
When the chemical mask is irradiated with X-rays, photoelectrons having energy specific to the elements contained in the base material 31 and the pattern portions 33 to 35 are emitted. That is, the photoelectrons emitted from the substrate 31 and the pattern portions 33 to 35 have different energy distributions. By analyzing the energy of such photoelectrons, the contained elements can be discriminated. This is widely known as photoelectron spectroscopy (PES).
[0073]
According to the exposure method of the present embodiment, the spectrolithography apparatus having the deflection energy analyzer shown in FIG. 4 is used. The voltage applied to the analyzer 22 of the deflection energy analyzer is adjusted, and the pass energy is set to the energy of the photoelectrons emitted from the specific pattern portion.
[0074]
In the spectrolithography apparatus, the chemical mask shown in FIG. 5 is irradiated with X-rays to emit photoelectrons. The emitted photoelectrons are taken into the incident lens system 21 of the deflection energy analyzer, and a monochromatic electron beam is emitted from the emission lens system 23. The wafer 24 is exposed by the monochromatic electron beam.
[0075]
Also in this embodiment, multiple exposure of complementary patterns can be performed. For example, so that photoelectrons are generated in the first complementary pattern portion 33 of FIG. 5, the first complementary X-ray irradiation is performed on the chemical mask, and then the photoelectrons are generated in the second complementary pattern portion 34. Then, the second X-ray irradiation is performed on the chemical mask. Accordingly, multiple exposure can be performed and the pattern can be transferred in a complementary manner without changing the chemical mask attached to the spectrolithography apparatus.
[0076]
According to the exposure method of this embodiment described above, as shown in FIG. 4, one surface of the chemical mask is irradiated with X-rays, and photoelectrons emitted from the other surface are incident on the deflection energy analyzer. Alternatively, although not shown, X-rays can be irradiated to one surface of the chemical mask, and photoelectrons emitted from the surface can be incident on a deflection energy analyzer to perform photoelectron energy selection.
[0077]
This configuration is common to the above-described reflective mask described in Japanese Patent No. 2957669 and the mask emitting secondary electrons described in Japanese Patent Application Laid-Open No. 2000-182943 in that the electron beam does not pass through the mask. However, the masks described in these publications are irradiated with a charged particle beam, whereas the chemical mask of the present embodiment is irradiated with X-rays, whereby photoelectrons are emitted. Therefore, the conventional mask described in the above publication is essentially different from the chemical mask of the present embodiment.
[0078]
The manufacturing method of the semiconductor device of this embodiment includes a step of transferring a pattern by exposing the resist applied to the wafer surface by the exposure method described above. Regardless of how many types of pattern portions are formed on the chemical mask, each pattern portion generates photoelectrons having specific energy.
Therefore, according to the method for manufacturing a semiconductor device of this embodiment, a pattern finer than the conventional one can be transferred to a resist with high accuracy, and the semiconductor device can be further highly integrated.
[0079]
Embodiments of the exposure method, exposure apparatus, semiconductor device manufacturing method, and mask of the present invention are not limited to the above description. For example, in the spectrolithographic apparatus of the fifth embodiment, instead of using an electron optical system as shown in FIG. 4, an enlargement imaging lens system used in a photoelectron microscope (PEEM) is adopted. Is also possible. In addition, various modifications can be made without departing from the scope of the present invention.
[0080]
【The invention's effect】
According to the exposure method and the exposure apparatus of the present invention, the monochromaticity of the beam transmitted through the mask is improved, and the resolution of the pattern is improved. According to the method for manufacturing a semiconductor device of the present invention, since a fine pattern can be transferred with high accuracy, the semiconductor device can be highly integrated. According to the mask of the present invention, a fine pattern can be transferred with high accuracy in a lithography process.
[Brief description of the drawings]
FIG. 1 is a schematic view showing the principle of an exposure method of the present invention.
FIG. 2 is a schematic view showing a part of an exposure apparatus according to Embodiment 1 of the present invention.
FIG. 3 is a schematic view showing a part of an exposure apparatus according to Embodiment 1 of the present invention.
FIG. 4 is a schematic view showing a part of an exposure apparatus according to Embodiment 2 of the present invention.
FIG. 5 is a plan view of a mask according to Embodiments 4 and 5 of the present invention.
FIG. 6 is a schematic view showing the principle of a conventional exposure method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,101 ... Charged particle beam source, 2,102 ... Mask front stage optical system, 3, 103 ... Mask, 4, 104 ... Mask back stage optical system, 4a ... Objective / intermediate lens, 5 ... Spectral system, 6, 105 ... Image Surface 11 Ω filter 12a to 12d Sector type electromagnet 13 Symmetrical surface 14 Entrance aperture 15 Energy selection slit 21 Incident lens system 22 Analyzer 23 Exit lens system 24 Wafer , 31 ... base material, 32 ... pattern part, 33 ... first complementary pattern part, 34 ... second complementary pattern part, 35 ... non-divided pattern part.

Claims (13)

An exposure apparatus that irradiates a photosensitive surface with a charged particle beam and transfers a pattern onto the photosensitive surface,
A charged particle beam source that emits the charged particle beam to a mask in which a charged particle beam transmitting portion is formed so as to correspond to the pattern ; and
An exposure apparatus comprising: energy sorting means for sorting charged particles having a specific energy out of charged particles transmitted through the mask and causing the particles to enter the photosensitive surface ;
The energy selecting means includes
An incident aperture surface that receives charged particles that have passed through the mask and excludes charged particles scattered by the mask in the incident charged particles;
An energy filter that separates orbits of charged particles that have passed through the entrance diaphragm surface according to energy;
In the charged particles whose orbits are separated according to the energy by the energy filter, an energy selection slit for passing charged particles having a specific energy;
including
Exposure device. The exposure apparatus according to claim 1, wherein the charged particles include electrons, and the energy filter includes an Ω filter. The exposure apparatus according to claim 1, wherein the charged particles include electrons, and the energy filter includes a Castaing type filter. The exposure apparatus according to claim 1, wherein the charged particles include electrons, and the energy filter includes a Wien filter. The exposure apparatus according to claim 1, wherein the charged particles include ions, and the energy filter includes a quadrupole mass filter. The exposure apparatus according to claim 1, wherein the energy filter includes a deflection energy analyzer. The exposure apparatus according to claim 6, wherein the charged particles include electrons, and the deflection energy analyzer includes an electrostatic deflection sector. The exposure apparatus according to claim 6, wherein the charged particles include electrons, and the deflection energy analyzer includes a magnetic field deflection sector. The exposure apparatus according to claim 6, wherein the charged particles include ions, and the deflection energy analyzer includes an electrostatic deflection sector. The exposure apparatus according to claim 6, wherein the charged particles include ions, and the deflection energy analyzer includes a magnetic field deflection sector. The exposure apparatus according to claim 6, wherein the deflection energy analyzer is a hemispherical energy analyzer that allows charged particles having passed through the mask to pass charged particles having energy determined by a radius and a voltage difference between an inner sphere and an outer sphere. A step of causing a charged particle beam to enter a mask in which a charged particle beam transmitting portion is formed in a predetermined pattern;
Selecting charged particles having specific energy among charged particles transmitted through the mask;
And a step of causing charged particles having specific energy to be incident on a photosensitive surface .
In the step of causing the charged particle beam to be incident on the mask, a charged particle beam having a specific energy is incident on the mask,
In the step of selecting charged particles that have passed through the mask,
In the charged particles that have passed through the mask, the charged particles scattered by the mask are eliminated on the entrance diaphragm surface,
The trajectory of the charged particles transmitted through the entrance diaphragm surface is separated according to energy by an energy filter,
In charged particles whose orbits are separated according to energy by the energy filter, charged particles having specific energy are passed through the energy selection slit.
Exposure method . A step of causing a charged particle beam to enter a mask in which a charged particle beam transmitting portion is formed in a predetermined pattern;
Selecting charged particles having specific energy among charged particles transmitted through the mask;
A method of manufacturing a semiconductor device, comprising the step of causing charged particles having specific energy selected to enter a resist and transferring the pattern onto the resist ,
In the step of causing the charged particle beam to be incident on the mask, a charged particle beam having a specific energy is incident on the mask,
In the step of selecting charged particles that have passed through the mask,
In the charged particles that have passed through the mask, the charged particles scattered by the mask are eliminated on the entrance diaphragm surface,
The trajectory of the charged particles transmitted through the entrance diaphragm surface is separated according to energy by an energy filter,
In charged particles whose orbits are separated according to energy by the energy filter, charged particles having specific energy are passed through the energy selection slit.
A method for manufacturing a semiconductor device .

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