JP3336438B2 - Projection exposure apparatus, exposure method, and circuit manufacturing method - Google Patents
Projection exposure apparatus, exposure method, and circuit manufacturing methodInfo
- Publication number
- JP3336438B2 JP3336438B2 JP34360191A JP34360191A JP3336438B2 JP 3336438 B2 JP3336438 B2 JP 3336438B2 JP 34360191 A JP34360191 A JP 34360191A JP 34360191 A JP34360191 A JP 34360191A JP 3336438 B2 JP3336438 B2 JP 3336438B2
- Authority
- JP
- Japan
- Prior art keywords
- light source
- annular
- projection
- secondary light
- exposure
- 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.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70058—Mask illumination systems
Description
【０００１】[0001]
【産業上の利用分野】本発明は、半導体集積回路等の製
造に要する微細パターンを基板（ウエハ）上に投影露光
する投影露光装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure apparatus for projecting and exposing a fine pattern required for manufacturing a semiconductor integrated circuit or the like onto a substrate (wafer).
【０００２】[0002]
【従来の技術】従来の投影露光装置としては、回路パタ
ーンが形成されたマスク、レチクル等の投影原版（以下
レチクルと称する。）に露光光を照明し、投影光学系を
介してウエハ等の基板（以下ウエハと称する。）上にレ
チクル上の回路パターン像を転写露光するものが知られ
ている。2. Description of the Related Art A conventional projection exposure apparatus illuminates a projection original (hereinafter referred to as a "reticle") such as a mask or a reticle on which a circuit pattern is formed with exposure light, and transmits a substrate such as a wafer via a projection optical system. (Hereinafter referred to as a wafer) is known in which a circuit pattern image on a reticle is transferred and exposed.
【０００３】ここで、レチクル上に転写される解像力
は、露光光の波長をλとし、投影光学系の開口数をＮＡ
とするとき、理論的には０．５×λ／ＮＡ程度である。
しかしながら、実際のリソグラフィ工程ではウエハの湾
曲、プロセスによるウエハの段差等の影響、またはフォ
トレジスト自体の厚さのために、ある程度の焦点深度が
必要となる。このため、焦点深度等の要因を加味した実
用的な解像力は、ｋ×λ／ＮＡとして表され、ここで、
ｋはプロセス係数と呼ばれ、通常０．７〜０．８程度で
ある。Here, the resolving power transferred onto the reticle is represented by the wavelength of exposure light as λ and the numerical aperture of the projection optical system as NA.
Is theoretically about 0.5 × λ / NA.
However, in the actual lithography process, a certain depth of focus is required due to the curvature of the wafer, the influence of the step of the wafer due to the process, or the thickness of the photoresist itself. For this reason, a practical resolving power in consideration of factors such as the depth of focus is expressed as k × λ / NA, where
k is called a process coefficient and is usually about 0.7 to 0.8.
【０００４】[0004]
【発明が解決しようとする課題】ところで、近年におい
ては、特にウエハ上に転写されるパターンの微細化が進
んでおり、この微細化に対応するための手法として、上
記の解像力の式から明らかな如く、露光光の短波長化、
あるいは、投影光学系の開口数ＮＡを大きくすることが
考えられる。In recent years, in particular, the pattern transferred onto a wafer has been miniaturized, and as a method for responding to this miniaturization, it is apparent from the above expression of the resolving power. As described above, shortening the wavelength of the exposure light,
Alternatively, it is conceivable to increase the numerical aperture NA of the projection optical system.
【０００５】しかし、露光光の短波長化を行う手法で
は、この露光光の短波長化に伴い投影光学系のレンズに
使用できる硝材は限られたものとなり、この制約された
硝材の中で十分なる収差補正が成された投影光学系を設
計することは困難である。また、投影光学系の開口数Ｎ
Ａを大きくする手法では、確かに解像力の向上は図れる
ものの、投影光学系の焦点深度が投影光学系の開口数Ｎ
Ａの二乗に反比例する。従って、焦点深度が著しく減少
するため好ましくない。しかも、大きな開口数ＮＡを持
ちながら十分に収差補正が成された投影光学系を設計す
ることは難しい。However, in the method of shortening the wavelength of the exposure light, the glass material that can be used for the lens of the projection optical system is limited due to the shortening of the wavelength of the exposure light. It is difficult to design a projection optical system with some aberration correction. Also, the numerical aperture N of the projection optical system
In the method of increasing A, although the resolution can be certainly improved, the depth of focus of the projection optical system is increased by the numerical aperture N of the projection optical system.
It is inversely proportional to the square of A. Accordingly, the depth of focus is undesirably reduced. In addition, it is difficult to design a projection optical system having a large numerical aperture NA and sufficiently correcting aberrations.
【０００６】本発明は、以上の課題に鑑みてなされたも
のであり、投影光学系の焦点深度を向上させることによ
り、実用上においてレチクル上の回路パターンをより高
解像度でウエハに忠実に転写できる投影露光装置を提供
することを目的としている。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a circuit pattern on a reticle can be transferred to a wafer with higher resolution in practical use by improving the depth of focus of a projection optical system. It is an object to provide a projection exposure apparatus.
【０００７】[0007]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明の投影露光装置は、照明光学系からの露光
光によって投影原版上のパターンを投影光学系を介して
基板上に投影露光する投影露光装置であって、前記照明
光学系は、露光光を供給する光源手段と、該光源手段か
らの光によって輪帯状の２次光源を形成する輪帯光源形
成手段と、該輪帯光源形成手段からの光束を前記投影原
版上に集光するコンデンサー光学系とを有し、前記輪帯
光源形成手段は、 １／３≦ｄ1 ／ｄ2 ≦２／３ （１） ０．４５≦ＮＡ2 ／ＮＡ1 ≦０．８ （２） を満足する輪帯状の２次光源と、円形状の２次光源とを
選択的に形成可能であるように構成したものである。但
し、 ｄ1 ：前記輪帯状の２次光源の内径 ｄ2 ：前記輪帯状の２次光源の外径 ＮＡ1 ：前記投影光学系の投影原版側の開口数 ＮＡ2 ：前記輪帯状の２次光源の外径により決定される
前記照明光学系の開口数である。In order to achieve the above object, a projection exposure apparatus according to the present invention projects a pattern on a projection original onto a substrate via a projection optical system by exposure light from an illumination optical system. A projection exposure apparatus that performs exposure, wherein the illumination optical system includes: a light source unit that supplies exposure light; an annular light source forming unit that forms an annular secondary light source using light from the light source unit; A condenser optical system for condensing a light beam from the light source forming means on the projection master, wherein the annular light source forming means: 1/3 ≦ d 1 / d 2 ≦ 2/3 (1) 0.45 ≦ NA 2 / NA 1 ≦ 0.8 (2) An annular secondary light source and a circular secondary light source satisfying the condition (2) can be selectively formed. Where, d 1 : inner diameter of the annular secondary light source d 2 : outer diameter of the annular secondary light source NA 1 : numerical aperture on the projection original side of the projection optical system NA 2 : secondary of the annular secondary light source The numerical aperture of the illumination optical system is determined by the outer diameter of the light source.
【０００８】また、本発明の露光方法は、照明光学系か
らの露光光によって投影原版上のパターンを基板へ露光
する露光方法であって、露光光を供給する工程と、該露
光光によって輪帯状の２次光源を形成する工程と、該輪
帯状の２次光源からの光束を前記投影原版上に集光する
工程と、投影光学系を介して前記投影原版上の前記パタ
ーンの像を前記基板に形成する工程とを有し、前記２次
光源を形成する工程は、上記条件式（１）及び（２）を
満足する輪帯状の２次光源と、円形状の２次光源とを選
択する工程を有するものである。The exposure method according to the present invention is an exposure method for exposing a pattern on a projection original to a substrate by exposure light from an illumination optical system. The exposure method comprises the steps of: supplying exposure light; Forming a secondary light source, condensing a light beam from the annular secondary light source on the projection master, and transferring the image of the pattern on the projection master via a projection optical system to the substrate. And forming the secondary light source. In the forming of the secondary light source, an annular secondary light source and a circular secondary light source satisfying the conditional expressions (1) and (2) are selected. It has a process.
【０００９】[0009]
【作 用】本発明は、光源手段からの露光用の光によっ
て輪帯状の２次光源を形成し、この輪帯状の面光源から
の光によってレチクル上を照明するという、所謂輪帯照
明（あるいは傾斜照明）を行うようにしたものである。
このとき、輪帯状の２次光源の内径をｄ1 、輪帯状の２
次光源の外径をｄ2 とするとき、 １／３≦ｄ1 ／ｄ2 ≦２／３ （１） を満足するように輪帯状の２次光源を形成することによ
り、投影光学系の焦点深度を向上させて実用的な解像力
の向上が達成できた。The present invention provides a so-called annular illumination (or so-called annular illumination) in which an annular secondary light source is formed by light for exposure from a light source means, and the light from the annular surface light source is illuminated on a reticle. Inclined illumination).
At this time, the inner diameter of the annular secondary light source is d 1 , and the annular secondary light source is
When the outer diameter of the secondary light source is d 2 , by forming the annular secondary light source so as to satisfy 1/3 ≦ d 1 / d 2 ≦ 2/3 (1), the focal point of the projection optical system is adjusted. By improving the depth, a practical improvement in resolution was achieved.
【００１０】具体的には、本発明によって、前述の如く
実用的な最小解像線幅に大きく関与するプロセス係数ｋ
を０．５程度に向上させることが可能となった。一例と
して、光源の波長λをｉ線（365nm ）、投影レンズのウ
エハ側の開口数ＮＡを０．４とするとき、プロセス係数
ｋを０．７とした従来の露光装置によって解像できる線
幅は、ｋ×λ／ＮＡより、０．６４μｍ程度となるが、
本発明による露光装置では、プロセス係数ｋが０．５程
度となるため、解像できる線幅は、０．４６μｍとな
る。従って、従来の装置よりも実用上十分なる焦点深度
を確保した上での解像度の向上が図れていることが分か
る。Specifically, according to the present invention, as described above, the process coefficient k which greatly contributes to the practical minimum resolution line width is described.
Can be improved to about 0.5. As an example, when the wavelength λ of the light source is i-line (365 nm) and the numerical aperture NA of the projection lens on the wafer side is 0.4, a line width that can be resolved by a conventional exposure apparatus with a process coefficient k of 0.7. Is about 0.64 μm from k × λ / NA,
In the exposure apparatus according to the present invention, since the process coefficient k is about 0.5, the resolvable line width is 0.46 μm. Therefore, it can be seen that the resolution is improved while securing a sufficient depth of focus practically more than the conventional device.
【００１１】ここで、条件（１）の下限値を越えると、
輪帯状光源の内径が小さくなり過ぎ、本発明による輪帯
照明の効果が薄れ、投影光学系の焦点深度と解像度とを
向上させることが困難となる。逆に条件（１）の上限を
越えると、レチクル上では同じ線幅のパターンでも周期
性の有無によりウエハ上に転写される線幅が異なり、レ
チクルパターンを忠実にウエハ上に転写することができ
なくなる。また、露光量変化に対する線幅の変化量が大
きくなるため、所望の線幅のパターンをウエハ上に形成
することが難しくなる。Here, if the lower limit of the condition (1) is exceeded,
The inner diameter of the annular light source becomes too small, the effect of the annular illumination according to the present invention is weakened, and it becomes difficult to improve the depth of focus and resolution of the projection optical system. Conversely, when the value exceeds the upper limit of the condition (1), the line width transferred onto the wafer differs depending on the presence or absence of the periodicity even on the reticle even if the pattern has the same line width, and the reticle pattern can be faithfully transferred onto the wafer. Disappears. Further, since the amount of change in the line width with respect to the change in the exposure amount becomes large, it becomes difficult to form a pattern having a desired line width on the wafer.
【００１２】さらに、本発明の輪帯照明による効果を十
分に引き出すためには、投影光学系の投影原版側の開口
数をＮＡ1 、輪帯状の２次的な光源の外径により決定さ
れる照明光学系の開口数をＮＡ2 とするとき、以下の条
件（２）を満足することが望ましい。 ０．４５≦ＮＡ2 ／ＮＡ1 ≦０．８ （２） この条件（２）の下限を越えると、輪帯照明によりレチ
クルを傾斜照明する光の入射角度が小さくなり、本発明
による輪帯照明の効果を殆ど得ることができない。この
ため、輪帯照明を行うこと自体無意味となってしまう。
逆に条件（２）の上限を越えると、空間像としての解像
度は向上するものの、焦点深度が低下する。さらには、
ベストフォーカスでのコントラストが大幅に低下するた
め好ましくない。Further, in order to sufficiently bring out the effects of the annular illumination of the present invention, the numerical aperture of the projection optical system on the projection original side is determined by NA 1 and the outer diameter of the annular secondary light source. When the numerical aperture of the illumination optical system is NA 2 , it is desirable that the following condition (2) is satisfied. 0.45 ≦ NA 2 / NA 1 ≦ 0.8 (2) When the lower limit of the condition (2) is exceeded, the angle of incidence of light for obliquely illuminating the reticle by the annular illumination is reduced, and the annular illumination according to the present invention is performed. Can hardly obtain the effect of. For this reason, it is meaningless to perform annular illumination.
Conversely, when the value exceeds the upper limit of the condition (2), the resolution as an aerial image is improved, but the depth of focus is reduced. Moreover,
This is not preferable because the contrast at the best focus is greatly reduced.
【００１３】[0013]
【実施例】図１は本発明による第１実施例の概略的構成
を示す図であり、以下、この図１を参照しながら本発明
による第１実施例を詳細に説明する。水銀アーク灯１か
らの光（例えば、ｇ線(436nm) 、ｉ線(365nm）等の光）
は、楕円鏡２によって集光され、反射鏡３を介して、コ
リメータレンズ４により平行光束に変換される。その
後、複数の棒状レンズ素子の集合体で構成されるフライ
アイレンズ５（オプティカルインテグレータ）を平行光
束が通過すると、これの射出側に複数の光源像が形成さ
れ、ここには、フライアイレンズ５を構成する棒状レン
ズ素子の数に相当する複数の２次的な光源が形成され
る。FIG. 1 is a diagram showing a schematic configuration of a first embodiment according to the present invention. Hereinafter, the first embodiment according to the present invention will be described in detail with reference to FIG. Light from mercury arc lamp 1 (for example, light of g-line (436 nm), i-line (365 nm), etc.)
Is condensed by the elliptical mirror 2 and is converted into a parallel light beam by the collimator lens 4 via the reflecting mirror 3. Thereafter, when a parallel light beam passes through a fly-eye lens 5 (optical integrator) composed of an aggregate of a plurality of rod-shaped lens elements, a plurality of light source images are formed on the exit side of the parallel light beam. Are formed, a plurality of secondary light sources corresponding to the number of the rod-shaped lens elements constituting.
【００１４】２次的光源が形成される位置には、輪帯状
の透過部を持つ開口絞り６が設けられており、ここには
輪帯状の複数の光源が形成される。開口絞り６は、図２
に示す如く、例えば石英等の透明基板上に輪帯状の透過
部６ａが形成される如くクロム等の遮光部６ｂ、６ｃの
蒸着によって形成されている。また、円形状の遮光部材
とそれよりも大きな円形状の開口を持つ遮光部材とで開
口絞り６を構成しても良い。At the position where the secondary light source is formed, an aperture stop 6 having a ring-shaped transmission portion is provided, and a plurality of ring-shaped light sources are formed here. The aperture stop 6 is shown in FIG.
As shown in FIG. 7, the light shielding portions 6b and 6c made of chrome or the like are formed by vapor deposition so that the ring-shaped transmitting portion 6a is formed on a transparent substrate made of quartz or the like. Further, the aperture stop 6 may be constituted by a circular light shielding member and a light shielding member having a larger circular opening.
【００１５】ここで、開口絞り６の遮光体６ｂの径（輪
帯状の透過部６ａの内径）をｄ1 、開口絞り６の遮光体
６ｃの径（輪帯状の透過部６ａの外径）をｄ2 とし、ｄ
1 ／ｄ2 を輪帯比と定義するとき、開口絞り６の輪帯比
は、１／３乃至２／３の範囲で構成されている。さて、
開口絞り６にて形成された複数の２次的光源からの光
は、反射鏡７を介して、コンデンサーレンズ８により集
光されて、レチクル９上の回路パターン９ａを斜め方向
から重畳的に均一照明する。すると、投影光学系１０に
よってウエハ１１上には、レチクル９上の回路パターン
像が形成される。従って、ウエハ１１上に塗布されたレ
ジストが感光されて、ここにはレチクル９上の回路パタ
ーン像が転写される。Here, the diameter of the light shield 6b of the aperture stop 6 (the inner diameter of the ring-shaped transmission portion 6a) is d 1 , and the diameter of the light shield 6c of the aperture stop 6 (the outer diameter of the ring-shaped transmission portion 6a) is d 1 . d 2 and d
When 1 / d 2 is defined as the annular ratio, the annular ratio of the aperture stop 6 is in the range of 範 囲 to ／. Now,
Light from a plurality of secondary light sources formed by the aperture stop 6 is condensed by a condenser lens 8 via a reflecting mirror 7, and the circuit pattern 9a on the reticle 9 is superposed and uniform in an oblique direction. Light up. Then, a circuit pattern image on the reticle 9 is formed on the wafer 11 by the projection optical system 10. Accordingly, the resist applied on the wafer 11 is exposed, and the circuit pattern image on the reticle 9 is transferred here.
【００１６】投影光学系１０の瞳（入射瞳）位置には、
開口絞り１０ａが設けられており、この開口絞り１０ａ
は、開口絞り６と共役に設けられている。図３は開口絞
り１０ａの円形状の開口部Ｐの様子を示したものであ
り、図示の如く、開口絞り１０ａの開口部Ａの内側に
は、輪帯状の２次光源の像Ｉが形成されており、この２
次光源の像Ｉの輪帯比（２次光源の像の内径Ｄ1 ／２次
光源の像の外径Ｄ2 ）は上述の開口絞り６の輪帯比と等
しくなっている。At the position of the pupil (entrance pupil) of the projection optical system 10,
An aperture stop 10a is provided.
Is provided conjugate with the aperture stop 6. FIG. 3 shows a state of a circular opening P of the aperture stop 10a. As shown in the drawing, an image I of the annular secondary light source is formed inside the opening A of the aperture stop 10a. This 2
The annular ratio of the image I of the secondary light source (the inner diameter D 1 of the image of the secondary light source / the external diameter D 2 of the image of the secondary light source) is equal to the annular ratio of the aperture stop 6 described above.
【００１７】ここで、開口絞り１０ａの開口部の径をＤ
3 とするとき、２次光源の像の外径と開口絞り１０ａの
開口部Ａの径との比率（Ｄ2 ／Ｄ3 ）は、コヒーレンス
ファクター、即ちσ値と呼ばれ、このとき、輪帯状２次
光源の像Ｉは、図３に示す如く、０．４５乃至０．８の
σ値の範囲で形成されている。なお、σ値は、図１に示
す如く、開口絞り１０ａの最周縁からの光軸Ａｘに平行
な光線Ｒ1 により決定される投影光学系１０のレチクル
側の開口数をＮＡ1(=sinθ1)とし、開口絞り６の最周縁
（最外径）からの光軸Ａｘに平行な光線Ｒ2 により決定
される照明光学系（１〜８）の開口数ＮＡ2(=sinθ2)と
するとき、σ値は、次式でも定義される。Here, the diameter of the aperture of the aperture stop 10a is D
When it is set to 3 , the ratio (D 2 / D 3 ) between the outer diameter of the image of the secondary light source and the diameter of the opening A of the aperture stop 10a is called a coherence factor, that is, a σ value. As shown in FIG. 3, the image I of the secondary light source is formed in a range of σ values of 0.45 to 0.8. As shown in FIG. 1, the σ value is a numerical aperture on the reticle side of the projection optical system 10 determined by a light ray R 1 parallel to the optical axis Ax from the outermost edge of the aperture stop 10 a as NA 1 (= sin θ 1). ), And the numerical aperture NA 2 (= sin θ 2 ) of the illumination optical system (1 to 8) determined by the ray R 2 parallel to the optical axis Ax from the outermost edge (outermost diameter) of the aperture stop 6. , Σ values are also defined by the following equation.
【００１８】σ＝ＮＡ2 ／ＮＡ1 ところで、開口絞り１０ａの口径を可変に構成して、σ
値を変化させると、焦点深度と解像度等とを制御するこ
とができる。従って、本実施例では、開口絞り６の配置
により輪帯照明を行っているため、焦点深度及び解像度
のより一層の向上が達成できるが、開口絞り１０ａの開
口部Ａの径を変化させてσ値を変更することにより、微
細なパターンを焼き付けが要求されるプロセス、深い焦
点深度が要求されるプロセス等の各プロセスに応じた最
適な照明状態を達成できる。Σ = NA 2 / NA 1 By the way, the aperture of the aperture stop 10a is configured to be variable and
By changing the value, it is possible to control the depth of focus, the resolution, and the like. Therefore, in the present embodiment, the annular illumination is performed by the arrangement of the aperture stop 6, so that it is possible to further improve the depth of focus and the resolution. However, by changing the diameter of the opening A of the aperture stop 10a, By changing the value, it is possible to achieve an optimal illumination state according to each process such as a process that requires printing of a fine pattern and a process that requires a deep depth of focus.
【００１９】また、図１では、開口絞り６を固定的に用
いた例を示したが、図４に示す如く、輪帯比が互いに異
なる複数の開口絞りを円周方向に沿って円形基板上に設
けてけも良い。図４では、１／３〜２／３の範囲内で互
いに異なる輪帯比を持つ第１の開口絞り群（６０ｂ〜６
０ｃ）と、この第１の開口絞り群とは異なる外径を有し
１／３〜２／３の範囲内で互いに異なる輪帯比を持つ第
２の開口絞り群（６０ｆ〜６０ｈ）とが透明な円形基板
６０上にクロム等の蒸着等により形成されている。そし
て、さらに、円形基板６０上には第１の開口絞り群の外
径と同じ径を持つ円形開口絞り６０ａと第２の開口絞り
群の外径と同じ径を持つ円形開口絞り６０ｅとが設けら
れている。FIG. 1 shows an example in which the aperture stop 6 is fixedly used. However, as shown in FIG. 4, a plurality of aperture stops having different ring zone ratios are formed on a circular substrate along the circumferential direction. May be provided. In FIG. 4, the first aperture stop group (60b to 6b) having different ring zone ratios within the range of 1/3 to 2/3.
0c) and a second aperture stop group (60f to 60h) having an outer diameter different from that of the first aperture stop group and having a ring ratio different from each other within a range of 1/3 to 2/3. It is formed on a transparent circular substrate 60 by vapor deposition of chromium or the like. Further, a circular aperture stop 60a having the same diameter as the outer diameter of the first aperture stop group and a circular aperture stop 60e having the same diameter as the outer diameter of the second aperture stop group are provided on the circular substrate 60. Have been.
【００２０】以上のターレット式による開口絞りを適宜
回転させて、最適な輪帯比を持つ開口絞り（６０ｂ〜６
０ｃ，６０ｆ〜６０ｈ）をフライアイレンズ６の射出側
に設定することにより、上述の如く、焦点深度と解像度
等とを制御することができるため、最適なσ値のもとで
の最適な輪帯照明が達成できる。また、通常に円形開口
も持つ開口絞り（６０ａ，６０ｅ）をフライアイレンズ
６の射出側に設定すれば、通常の照明による露光を行う
ことができる。The turret-type aperture stop is appropriately rotated to obtain an aperture stop (60b to 60b) having an optimum annular ratio.
0c, 60f to 60h) on the exit side of the fly-eye lens 6, it is possible to control the depth of focus and the resolution as described above. Band illumination can be achieved. If the aperture stop (60a, 60e) having a circular aperture is set on the exit side of the fly-eye lens 6, exposure with normal illumination can be performed.
【００２１】さらには、プロセス情報、必要とされる焦
点深度の情報さらには露光されるべき最小線幅等の情報
を含むバーコード等のマークを持つレチクルを用い、こ
のマークを検知するマーク検知手段を設けても良い。こ
れにより、このマーク検知手段を介して検知された情報
に基づいて、上記ターレット式等による交換可能な開口
絞りの適切な輪帯比、適切なσ値を自動的に設定するよ
うにしても良い。Further, a mark detecting means for detecting a mark by using a reticle having a mark such as a bar code including process information, required depth of focus information, and information such as a minimum line width to be exposed. May be provided. Thereby, based on the information detected through the mark detecting means, an appropriate zonal ratio and an appropriate σ value of the replaceable aperture stop using the turret method or the like may be automatically set. .
【００２２】次に、図５は本発明による第２実施例の概
略的構成を示す図であり、この図５を参照しながら本発
明による第２実施例を説明する。図１の第１実施例の構
成と同じ機能を持つ部材には同じ符号を付してある。第
２実施例が第１実施例と異なる点は、フライアイレンズ
５と反射鏡７との間に設けられていた開口絞り６の代わ
りに、集光レンズ２０と、入射側が円形状に束ねられる
と共に射出側が輪帯状に束ねられた複数の光フアイバー
より構成されるライトガイド２１とを設け、フライアイ
レンズ５からの光束を遮光することなく輪帯状の多数の
光源を形成した点である。Next, FIG. 5 is a view showing a schematic configuration of a second embodiment according to the present invention. The second embodiment according to the present invention will be described with reference to FIG. Members having the same functions as those in the configuration of the first embodiment in FIG. 1 are denoted by the same reference numerals. The second embodiment is different from the first embodiment in that a condenser lens 20 and an incident side are bundled in a circular shape instead of the aperture stop 6 provided between the fly-eye lens 5 and the reflecting mirror 7. In addition, a light guide 21 composed of a plurality of optical fibers bundled in an annular shape on the emission side is provided, and a large number of annular light sources are formed without blocking light from the fly-eye lens 5.
【００２３】このライトガイド２１の入射端には、図６
に示す如く、複数のフアイバーを束ねる円形状部材２１
ａが設けられており、これの射出端には複数のフアイバ
ーを輪帯状に束ねる輪帯状部材２１ｂが設けられてい
る。ここで、ライトガイド２１の射出端の外径に対する
内径の比率、即ち輪帯比は１／３乃至２／３となるよう
に構成されており、投影光学系の開口絞り１０ａの位置
には、図３に示した如く、σ値が０．４５乃至０．８程
度となる輪帯状の光源像が形成される。FIG. 6 shows the incident end of the light guide 21.
As shown in the figure, a circular member 21 for bundling a plurality of fibers.
a is provided, and a ring-shaped member 21b for bundling a plurality of fibers in a ring shape is provided at the emission end. Here, the ratio of the inner diameter to the outer diameter of the exit end of the light guide 21, that is, the annular zone ratio is configured to be 乃至 to 、, and the position of the aperture stop 10 a of the projection optical system is As shown in FIG. 3, an annular light source image having a σ value of about 0.45 to 0.8 is formed.
【００２４】以上の構成により、本実施例では、光源１
からの光を何ら遮光することなく効率良く輪帯照明が行
えるため、焦点深度及び解像度のより一層の向上が達成
できるのみならず、高いスループットのもとでの露光を
達成することができる。なお、本実施例でも、上述の如
く、レチクル上に各種の情報を盛り込んだマークを検知
する手段を設け、この検知情報に基づいて、開口絞り１
０ａの開口部の最適な径を設定し、最適なσ値のもとで
の輪帯照明を行うようにしても良い。With the above configuration, in this embodiment, the light source 1
Since the annular illumination can be performed efficiently without blocking any light from the illuminator, not only the depth of focus and the resolution can be further improved, but also the exposure under a high throughput can be achieved. In this embodiment, as described above, means for detecting a mark including various information on the reticle is provided, and the aperture stop 1 is provided based on the detected information.
The optimal diameter of the opening of 0a may be set, and annular illumination may be performed under an optimal σ value.
【００２５】また、本発明による装置の光源としてエキ
シマレーザ（ＫｒＦ:248mn、ＡｒＦ:193mn等）を用いて
も良いことは言うまでもない。It goes without saying that an excimer laser (KrF: 248 mn, ArF: 193 mn, etc.) may be used as the light source of the apparatus according to the present invention.
【００２６】[0026]
【発明の効果】以上の如く、本発明によれば、従来の投
影露光装置よりも大きな焦点深度を確保できるため、実
用上より高い解像度のもとでの露光が実現できる。これ
により、従来の投影露光装置よりも、さらに微細なパタ
ーンをウエハ上に転写することができる。As described above, according to the present invention, a larger depth of focus can be ensured than in a conventional projection exposure apparatus, so that exposure at a resolution higher than practical can be realized. Thereby, a finer pattern can be transferred onto the wafer than a conventional projection exposure apparatus.
【図１】図１は本発明による第１実施例の概略的構成を
示す図である。FIG. 1 is a diagram showing a schematic configuration of a first embodiment according to the present invention.
【図２】図２は開口絞りの様子を示す平面図である。FIG. 2 is a plan view showing a state of an aperture stop.
【図３】図３は投影光学系の瞳位置に設けられた開口絞
りの開口部の様子を示す図である。FIG. 3 is a diagram illustrating a state of an aperture of an aperture stop provided at a pupil position of the projection optical system.
【図４】輪帯照明を行うための開口絞りをターレット式
にした様子を示す図である。FIG. 4 is a diagram showing a turret type aperture stop for performing annular illumination.
【図５】本発明による第２実施例の概略的構成を示す図
である。 FIG. 5 is a diagram showing a schematic configuration of a second embodiment according to the present invention.
It is.
【図６】ライトガイドの様子を示す斜示図である。FIG. 6 is a perspective view showing a state of a light guide.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭61−91662（ＪＰ，Ａ) 特開 平５−67553（ＪＰ，Ａ) 特開 平５−41345（ＪＰ，Ａ) 特開 平５−36585（ＪＰ，Ａ) 特開 平５−121290（ＪＰ，Ａ) 実開 昭61−151（ＪＰ，Ｕ) 第52回応用物理学会学術講演会予稿集 Ｎｏ．２ 601頁 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-91662 (JP, A) JP-A-5-67553 (JP, A) JP-A-5-41345 (JP, A) JP-A-5-41345 36585 (JP, A) Japanese Patent Laid-Open No. 5-121290 (JP, A) Japanese Utility Model Application Sho 61-151 (JP, U) Proceedings of the 52nd JSAP Academic Lecture No. 2 601 pages
Claims (22)
上のパターンを投影光学系を介して基板上に投影露光す
る投影露光装置において、 前記照明光学系は、露光光を供給する光源手段と、該光
源手段からの光によって輪帯状の２次光源を形成する輪
帯光源形成手段と、該輪帯光源形成手段からの光束を前
記投影原版上に集光するコンデンサー光学系とを有し、 前記輪帯光源形成手段は、 １／３≦ｄ1 ／ｄ2 ≦２／３ ０．４５≦ＮＡ2 ／ＮＡ1 ≦０．８ を満足する輪帯状の２次光源と、円形状の２次光源とを
選択的に形成可能であることを特徴とする投影露光装
置。 但し、 ｄ1 ：前記輪帯状の２次光源の内径 ｄ2 ：前記輪帯状の２次光源の外径 ＮＡ1 ：前記投影光学系の投影原版側の開口数 ＮＡ2 ：前記輪帯状の２次光源の外径により決定される
前記照明光学系の開口数である。1. A projection exposure apparatus for projecting and exposing a pattern on a projection original onto a substrate via a projection optical system by exposure light from an illumination optical system, wherein the illumination optical system comprises: a light source means for supplying exposure light; Having an annular light source forming means for forming an annular secondary light source by light from the light source means, and a condenser optical system for condensing a light beam from the annular light source forming means on the projection original, The annular light source forming means includes: an annular secondary light source that satisfies 1/3 ≦ d 1 / d 2 ≦ 2/3 0.45 ≦ NA 2 / NA 1 ≦ 0.8; and a circular secondary light source. A projection exposure apparatus capable of selectively forming a light source. Where, d 1 : inner diameter of the annular secondary light source d 2 : outer diameter of the annular secondary light source NA 1 : numerical aperture on the projection original side of the projection optical system NA 2 : secondary of the annular secondary light source The numerical aperture of the illumination optical system is determined by the outer diameter of the light source.
情報に応じて設定するための手段とをさらに備えること
を特徴とする請求項１記載の投影露光装置。2. An apparatus according to claim 1, further comprising an input unit for inputting process information, and a unit for setting a secondary light source formed by said annular light source forming unit in accordance with the process information. 2. The projection exposure apparatus according to claim 1.
て前記プロセス情報を含むマークを検知するためのマー
ク検知手段を有することを特徴とする請求項３記載の投
影露光装置。3. The projection exposure apparatus according to claim 3, wherein said input means includes a mark detection means provided on said projection original for detecting a mark including said process information.
た開口絞りを有し、 前記入力手段からの情報に基づいて前記投影光学系の前
記開口絞りの口径を設定する手段を有することを特徴と
する請求項２又は３記載の投影露光装置。4. The projection optical system has an aperture stop with a variable aperture, and has means for setting the aperture of the aperture stop of the projection optical system based on information from the input means. 4. The projection exposure apparatus according to claim 2, wherein:
ある輪帯状の２次光源と、前記第１の輪帯比とは異なる
第２の輪帯比である輪帯状の２次光源とを選択的に形成
可能であり、前記輪帯状の２次光源の内径をｄ1 、前記
輪帯状の２次光源の外径をｄ2 とするとき、前記第１お
よび第２の輪帯比はともに、 １／３≦ｄ1 ／ｄ2 ≦２／３ なる条件を満足することを特徴とする請求項1乃至４の
何れか一項記載の投影露光装置。5. The annular light source forming means includes an annular secondary light source having a first annular ratio, and an annular secondary light source having a second annular ratio different from the first annular ratio. The secondary light source can be selectively formed. When the inner diameter of the annular secondary light source is d 1 and the outer diameter of the annular secondary light source is d 2 , the first and second light sources are formed. annular ratio together, 1/3 ≦ d 1 / d projection exposure apparatus according to any one of claims 1 to 4, characterized by satisfying the 2 ≦ 2/3 following condition.
ンテグレータと、輪帯形状の開口を有する絞りとを備え
ることを特徴とする請求項１乃至５の何れか一項記載の
投影露光装置。6. The projection exposure apparatus according to claim 1, wherein said annular light source forming means includes an optical integrator and a stop having an annular aperture.
ことを特徴とする請求項１乃至６の何れか一項記載の投
影露光装置。7. The projection exposure apparatus according to claim 1, wherein said light source means comprises an excimer laser.
２次光源の外径に対する内径の比率を変更可能にする手
段を有することを特徴とする請求項１乃至７の何れか一
項記載の投影露光装置。8. The annular light source forming means includes means for changing a ratio of an inner diameter to an outer diameter of the annular secondary light source. Item 3. The projection exposure apparatus according to Item 1.
２次光源の外径の大きさを変更可能にすることを特徴と
する請求項１乃至８の何れか一項記載の投影露光装置。9. The projection according to claim 1, wherein said annular light source forming means is capable of changing the size of the outer diameter of said annular secondary light source. Exposure equipment.
２次光源の大きさを変更可能にすることを特徴とする請
求項１乃至９の何れか一項記載の投影露光装置。10. The projection exposure apparatus according to claim 1, wherein said annular light source forming means is capable of changing the size of said circular secondary light source.
露光方法において、 請求項１乃至１０の何れか一項記載の投影露光装置を用
いて前記投影原版を照明し、照明された前記パターンを
前記基板へ転写することを特徴とする露光方法。11. An exposure method for exposing a pattern on a projection original to a substrate, wherein the projection original is illuminated using the projection exposure apparatus according to claim 1, and the illuminated pattern is exposed. An exposure method, wherein the image is transferred to the substrate.
写する工程を含む回路の製造方法において、 請求項１乃至１０の何れか一項記載の投影露光装置の前
記照明光学系を用いて前記投影原版を照明し、前記投影
光学系を用いて前記回路パターンの像を前記基板上に形
成することを特徴とする回路の製造方法。12. A method of manufacturing a circuit including a step of transferring a circuit pattern on a projection original onto a substrate, wherein the illumination optical system of the projection exposure apparatus according to claim 1 is used. A method of manufacturing a circuit, comprising: illuminating a projection master and forming an image of the circuit pattern on the substrate using the projection optical system.
版上のパターンを基板へ露光する露光方法において、 露光光を供給する工程と、 該露光光によって輪帯状の２次光源を形成する工程と、 該輪帯状の２次光源からの光束を前記投影原版上に集光
する工程と、 投影光学系を介して前記投影原版上の前記パターンの像
を前記基板に形成する工程とを有し、 前記２次光源を形成する工程は、 １／３≦ｄ1 ／ｄ2 ≦２／３ ０．４５≦ＮＡ2 ／ＮＡ1 ≦０．８ を満足する輪帯状の２次光源と、円形状の２次光源とを
選択する工程を有することを特徴とする露光方法。 但し、 ｄ1 ：前記輪帯状の２次光源の内径 ｄ2 ：前記輪帯状の２次光源の外径 ＮＡ1 ：前記投影光学系の投影原版側の開口数 ＮＡ2 ：前記輪帯状の２次光源の外径により決定される
前記照明光学系の開口数である。13. An exposure method for exposing a pattern on a projection original to a substrate by exposure light from an illumination optical system, comprising the steps of: supplying exposure light; and forming an annular secondary light source with the exposure light. Converging a light beam from the annular secondary light source on the projection master; and forming an image of the pattern on the projection master on the substrate via a projection optical system, The step of forming the secondary light source includes: an annular secondary light source satisfying 1/3 ≦ d 1 / d 2 ≦ 2/3 0.45 ≦ NA 2 / NA 1 ≦ 0.8; An exposure method comprising a step of selecting a secondary light source. Where, d 1 : inner diameter of the annular secondary light source d 2 : outer diameter of the annular secondary light source NA 1 : numerical aperture on the projection original side of the projection optical system NA 2 : secondary of the annular secondary light source The numerical aperture of the illumination optical system is determined by the outer diameter of the light source.
をさらに有することを特徴とする請求項１３記載の露光
方法。14. The exposure method according to claim 13, further comprising: a step of inputting process information; and a step of setting said secondary light source according to said process information.
設けられて前記プロセス情報を含むマークを検知する補
助工程を有することを特徴とする請求項１４記載の露光
方法。15. The exposure method according to claim 14, wherein the inputting step includes an auxiliary step of detecting a mark provided on the projection original and including the process information.
系中の開口絞りの口径を設定する工程をさらに有するこ
とを特徴とする請求項１４又は１５記載の露光方法。16. An exposure method according to claim 14, further comprising the step of setting the aperture of an aperture stop in said projection optical system according to said process information.
光光をオプティカルインテグレータへ導く工程と、該オ
プティカルインテグレータからの前記露光光を輪帯形状
の開口を有する絞りへ導く工程とを有することを特徴と
する請求項１３乃至１６の何れか一項記載の露光方法。17. The step of forming the secondary light source includes a step of guiding the exposure light to an optical integrator, and a step of guiding the exposure light from the optical integrator to a stop having a ring-shaped opening. The exposure method according to any one of claims 13 to 16, wherein:
れることを特徴とする請求項１３乃至１７の何れか一項
記載の露光方法。18. The exposure method according to claim 13, wherein said exposure light is supplied from an excimer laser.
径の比率を変更する工程をさらに含むことを特徴とする
請求項１４乃至１６の何れか一項記載の露光方法。19. The exposure method according to claim 14, further comprising a step of changing a ratio of an inner diameter to an outer diameter of said annular secondary light source.
径の比率を変更する工程では、前記輪帯形状の２次光源
の前記内径をｄ1 とし、前記外径をｄ2 とするとき、 １／３≦ｄ1 ／ｄ2 ≦２／３ の範囲内で変更することを特徴とする請求項１９記載の
露光方法。20. The step of changing the ratio of the inner diameter to the outer diameter of the annular secondary light source, wherein the inner diameter of the annular secondary light source is d 1 and the outer diameter is d 2. , 1/3 the exposure method according to claim 19, wherein the change in the range of ≦ d 1 / d 2 ≦ 2 /3.
を変更する工程をさらに有することを特徴とする請求項
１３乃至２０の何れか一項記載の露光方法。21. The exposure method according to claim 13, further comprising a step of changing the outer diameter of the secondary light source having the annular shape.
る工程をさらに有することを特徴とする請求項１３乃至
２１の何れか一項記載の露光方法。22. The exposure method according to claim 13, further comprising a step of changing a size of said circular secondary light source.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34360191A JP3336438B2 (en) | 1991-12-25 | 1991-12-25 | Projection exposure apparatus, exposure method, and circuit manufacturing method |
| US08/370,216 US5530518A (en) | 1991-12-25 | 1994-12-07 | Projection exposure apparatus |
| US08/480,863 US5576801A (en) | 1991-12-25 | 1995-06-07 | Projection exposure apparatus |
| US09/320,472 USRE39662E1 (en) | 1991-12-25 | 1999-05-25 | Projection exposure apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34360191A JP3336438B2 (en) | 1991-12-25 | 1991-12-25 | Projection exposure apparatus, exposure method, and circuit manufacturing method |
Related Child Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000173209A Division JP2001028335A (en) | 2000-01-01 | 2000-06-09 | Projection aligner and method therefor, and manufacture of circuit thereof |
| JP2002064764A Division JP2002353131A (en) | 2002-03-11 | 2002-03-11 | Projection aligner and aligning method, and method for fabricating circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05175101A JPH05175101A (en) | 1993-07-13 |
| JP3336438B2 true JP3336438B2 (en) | 2002-10-21 |
Family
ID=18362796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34360191A Expired - Lifetime JP3336438B2 (en) | 1991-12-25 | 1991-12-25 | Projection exposure apparatus, exposure method, and circuit manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3336438B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0722242B1 (en) * | 1995-01-11 | 2003-04-02 | Dainippon Screen Mfg. Co., Ltd. | Image reading apparatus |
| KR20000066337A (en) * | 1999-04-15 | 2000-11-15 | 김영환 | Semiconductor Exposure System |
| JP2001028335A (en) * | 2000-01-01 | 2001-01-30 | Nikon Corp | Projection aligner and method therefor, and manufacture of circuit thereof |
-
1991
- 1991-12-25 JP JP34360191A patent/JP3336438B2/en not_active Expired - Lifetime
Non-Patent Citations (1)
| Title |
|---|
| 第５２回応用物理学会学術講演会予稿集 Ｎｏ．２ ６０１頁 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05175101A (en) | 1993-07-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6004699A (en) | Photomask used for projection exposure with phase shifted auxiliary pattern | |
| KR100955293B1 (en) | Lithographic method of manufacturing a device | |
| US5296892A (en) | Illuminating apparatus and projection exposure apparatus provided with such an illuminating apparatus | |
| US6780574B2 (en) | Multiple exposure method | |
| US20020076622A1 (en) | Structure and method of correcting proximity effects in a tri-tone attenuated phase-shifting mask | |
| JP3295956B2 (en) | Exposure apparatus and method for manufacturing semiconductor element | |
| US5576801A (en) | Projection exposure apparatus | |
| US4906080A (en) | Optical arrangement for projection exposure | |
| US20060197933A1 (en) | Exposure apparatus | |
| JPH11143047A (en) | Photomask and its production | |
| US6441886B2 (en) | Illumination optical system and exposure apparatus having the same | |
| JP3336438B2 (en) | Projection exposure apparatus, exposure method, and circuit manufacturing method | |
| JP3262074B2 (en) | Exposure method and exposure apparatus | |
| US5733687A (en) | Photomask, exposing method using photomask, and manufacturing method of photomask | |
| US6480263B1 (en) | Apparatus and method for phase shift photomasking | |
| JPH07248612A (en) | Master drawing substrate for projection exposure and projection exposure method | |
| KR100434954B1 (en) | Method for exposing of semiconductor device | |
| JPH10275769A (en) | Exposure method | |
| JP2001028335A (en) | Projection aligner and method therefor, and manufacture of circuit thereof | |
| JP2002353131A (en) | Projection aligner and aligning method, and method for fabricating circuit | |
| USRE39662E1 (en) | Projection exposure apparatus | |
| KR960039111A (en) | Photographing Process and Mask for Linewidth Control of Photoresist Pattern | |
| JP3296346B2 (en) | Exposure apparatus and method for manufacturing semiconductor element | |
| JP3296348B2 (en) | Projection exposure apparatus and method, and method for manufacturing semiconductor element | |
| JPH04212154A (en) | Photomask |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110809 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110809 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120809 Year of fee payment: 10 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120809 Year of fee payment: 10 |