JP2000021721A - Exposure method and aligner - Google Patents
Exposure method and alignerInfo
- Publication number
- JP2000021721A JP2000021721A JP10184239A JP18423998A JP2000021721A JP 2000021721 A JP2000021721 A JP 2000021721A JP 10184239 A JP10184239 A JP 10184239A JP 18423998 A JP18423998 A JP 18423998A JP 2000021721 A JP2000021721 A JP 2000021721A
- Authority
- JP
- Japan
- Prior art keywords
- exposure
- optical system
- projection optical
- pattern
- mask pattern
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
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
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は，露光方法及び露光
装置に関し、特に微細な回路パタ−ンを感光基板上に露
光する露光方法および露光装置に関し、本発明の露光方
法及び露光装置は、例えばＩＣ，ＬＳＩ等の半導体チッ
プ、液晶パネル等の表示素子、磁気ヘッド等の検出素
子、ＣＣＤ等の撮像素子といった各種デバイスの製造に
用いられる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure method and an exposure apparatus, and more particularly to an exposure method and an exposure apparatus for exposing fine circuit patterns on a photosensitive substrate. It is used for manufacturing various devices such as semiconductor chips such as ICs and LSIs, display elements such as liquid crystal panels, detection elements such as magnetic heads, and image pickup elements such as CCDs.
【０００２】[0002]
【従来の技術】従来より、ＩＣ，ＬＳＩ、液晶パネル等
のデバイスをフォトリソグラフィ−技術を用いて製造す
る時には、フォトマスク又はレチクル等（以下、「マス
ク」と記す。）の回路パタ−ンを投影光学系によってフ
ォトレジスト等が塗布されたシリコンウエハ又はガラス
プレ−ト等（以下、「ウエハ」と記す。）の感光基板上
に投影し、そこに転写する（露光する）投影露光方法及
び投影露光装置が使用されている。2. Description of the Related Art Conventionally, when manufacturing devices such as ICs, LSIs, and liquid crystal panels using photolithography technology, circuit patterns such as photomasks or reticles (hereinafter, referred to as "masks") are used. A projection exposure method and a projection exposure method in which a projection optical system projects onto a photosensitive substrate such as a silicon wafer or a glass plate or the like (hereinafter, referred to as a “wafer”) coated with a photoresist or the like and transfers (exposes) the same onto the photosensitive substrate. The device is being used.
【０００３】上記デバイスの高集積化に対応して、ウエ
ハに転写するパタ−ンの微細化即ち高解像度化とウエハ
における1チップの大面積化とが要求されており、従っ
てウエハに対する微細加工技術の中心を成す上記投影露
光方法及び投影露光装置においても、現在、０．５μｍ
以下の寸法（線幅）の像を広範囲に形成するべく、解像
度と露光面積の向上が計られている。In response to the high integration of the above-mentioned devices, there is a demand for a fine pattern, ie, a high resolution, to be transferred to a wafer and a large area of one chip on the wafer. In the projection exposure method and the projection exposure apparatus which form the center of
In order to form an image having the following dimensions (line width) in a wide range, resolution and exposure area are improved.
【０００４】従来の投影露光装置の摸式図を図１５に示
す。図１５中，191は遠紫外線露光用光源であるエキシ
マ−レ−ザ、192は照明光学系、193は照明光、194はマ
スク、195はマスク194４から出て光学系196に入射する
物体側露光光、196は縮小投影光学系、197は光学系196
から出て基板198に入射する像側露光光、198は感光基板
であるウエハ、199は感光基板を保持する基板ステージ
を、示す。FIG. 15 is a schematic diagram of a conventional projection exposure apparatus. In FIG. 15, reference numeral 191 denotes an excimer laser which is a light source for exposure to far ultraviolet rays, 192 denotes an illumination optical system, 193 denotes illumination light, 194 denotes a mask, and 195 denotes an object side exposure coming out of the mask 1944 and entering the optical system 196. Light, 196 is reduction projection optical system, 197 is optical system 196
198 denotes a wafer which is a photosensitive substrate, and 199 denotes a substrate stage for holding the photosensitive substrate.
【０００５】エキシマレ−ザ191から出射したレ−ザ光
は、引き回し光学系によって照明光学系192に導光さ
れ、投影光学系192により所定の光強度分布、配光分
布、開き角（開口数ＮＡ）等を持つ照明光193となるよ
うに調整され、マスク194を照明する。The laser light emitted from the excimer laser 191 is guided to an illumination optical system 192 by a drawing optical system, and a predetermined light intensity distribution, a light distribution, and an opening angle (numerical aperture NA) are projected by a projection optical system 192. ) Is adjusted so as to become the illumination light 193, and illuminates the mask 194.
【０００６】マスク194にはウエハ198上に形成する微細
パタ−ンを投影光学系192の投影倍率の逆数倍（例えば2
倍や4倍や5倍）した寸法のパターンがクロム等によって
石英基板上に形成されており、照明光193はマスク194の
微細パターンによって透過回折され、物体側露光光195
となる。On the mask 194, a fine pattern to be formed on the wafer 198 is inversely multiplied by a projection magnification of the projection optical system 192 (for example, 2).
(4 times, 4 times, 5 times) are formed on the quartz substrate by chrome or the like. The illumination light 193 is transmitted and diffracted by the fine pattern of the mask 194, and the object side exposure light 195
Becomes
【０００７】投影光学系196は、物体側露光光195を、マ
スク194の微細パターンを上記投影倍率で且つ充分小さ
な収差でウエハ198上に結像する像側露光光197に変換す
る。像側露光光197は図19の下部の拡大図に示されるよ
うに、所定の開口数ＮＡ (＝sinθ )でウエハ198上に収
束し，ウエハ198上に微細パターンの像を結ぶ。The projection optical system 196 converts the object-side exposure light 195 into image-side exposure light 197 that forms a fine pattern of the mask 194 on the wafer 198 at the above-mentioned projection magnification and with a sufficiently small aberration. The image side exposure light 197 converges on the wafer 198 at a predetermined numerical aperture NA (= sin θ) as shown in the enlarged view at the bottom of FIG. 19, and forms an image of a fine pattern on the wafer 198.
【０００８】基板ステ−ジ199は、ウエハ198の互いに異
なる複数の領域（ショット領域：１個又は複数のチップ
となる領域）に順次微細パタ−ンを形成する場合に、投
影光学系の像平面に沿ってステップ移動することにより
ウエハ198の投影光学系１９６に対する位置を変える。The substrate stage 199 is used to form a fine pattern sequentially on a plurality of different areas (shot areas: areas forming one or a plurality of chips) of the wafer 198. , The position of the wafer 198 with respect to the projection optical system 196 is changed.
【０００９】しかしながら、現在主流の上記のエキシマ
レーザを光源とする投影露光装置は，０．１５μｍ以下
のパタ−ンを形成することが困難である。However, it is difficult for a projection exposure apparatus using the above-described excimer laser as a light source to form a pattern of 0.15 μm or less.
【００１０】投影光学系196は、露光（に用いる）波長
に起因する光学的な解像度と焦点深度との間のトレ−ド
オフによる解像度の限界がある。投影露光装置による解
像パタ−ンの解像度Ｒと焦点深度ＤＯＦは，次の(1)式
と(2)式の如きレ−リ−の式によって表される。The projection optical system 196 has a resolution limit due to a trade-off between the optical resolution due to (exposure) wavelength and the depth of focus. The resolution R of the resolution pattern and the depth of focus DOF by the projection exposure apparatus are expressed by the following relay equations such as equations (1) and (2).
【００１１】 Ｒ＝ｋ1（λ／ＮＡ） ……（１） ＤＯＦ＝ｋ2（λ／ＮＡ2） ……（２） ここで、λは露光波長、NAは投影光学系196の明るさを
表す像側の開口数、ｋ1、ｋ2はウエハ198の現像プロセ
ス特性等によって決まる定数であり，通常０．５〜０．
７程度の値である。R = k 1 (λ / NA) (1) DOF = k 2 (λ / NA 2 ) (2) where λ is the exposure wavelength, and NA is the brightness of the projection optical system 196. The numerical aperture on the image side, k 1 , and k 2, which are represented, are constants determined by the development process characteristics of the wafer 198 and the like.
The value is about 7.
【００１２】この(1)式と(2)式から、解像度Rを小さい
値とする高解像度化には開口数NAを大きくする「高ＮＡ
化」があるが、実際の露光では投影光学系196の焦点深
度ＤＯＦをある程度以上の値にする必要があるため、高
NA化をある程度以上進めることは不可能となることと、
高解像度化には結局露光波長λを小さくする「短波長
化」が必要となることとが分かる。From the equations (1) and (2), it can be seen from the equations (1) and (2) that the numerical aperture NA is increased in order to increase the resolution R to a small value.
However, in actual exposure, the depth of focus DOF of the projection optical system 196 needs to be set to a certain value or more.
It is impossible to advance NA to some extent,
It can be seen that, in order to increase the resolution, "short wavelength" for reducing the exposure wavelength λ is necessary.
【００１３】ところが短波長化を進めていくと重大な問
題が発生する。この問題とは投影光学系196のレンズの
硝材がなくなってしまうことである。殆どの硝材の透過
率は遠紫外線領域では0に近く、特別な製造方法を用い
て露光装置用（露光波長約248nm）に製造された硝材と
して溶融石英が現存するが，この溶融石英の透過率も波
長193nm以下の露光波長に対しては急激に低下するし、
０．１５μｍ以下の微細パタ−ンに対応する露光波長１
５０ｎｍ以下の領域では実用的な硝材の開発は非常に困
難である。また遠紫外線領域で使用される硝材は、透過
率以外にも、耐久性，屈折率均一性，光学的歪み，加工
性等の複数条件を満たす必要があり、この事から、実用
的な硝材の存在が危ぶまれている。However, as the wavelength becomes shorter, a serious problem arises. This problem is that the glass material of the lens of the projection optical system 196 runs out. The transmittance of most glass materials is close to 0 in the deep ultraviolet region, and fused quartz currently exists as a glass material manufactured for exposure equipment (exposure wavelength: about 248 nm) using a special manufacturing method. Also decreases sharply for exposure wavelengths below 193 nm,
Exposure wavelength 1 corresponding to a fine pattern of 0.15 μm or less
It is extremely difficult to develop a practical glass material in the region of 50 nm or less. In addition, the glass material used in the deep ultraviolet region must satisfy various conditions such as durability, uniformity of refractive index, optical distortion, workability, etc., in addition to transmittance. Existence is at stake.
【００１４】このように従来の投影露光方法及び投影露
光装置では、ウエハ198に０．１５μｍ以下のパタ−ン
を形成する為には１５０ｎｍ程度以下まで露光波長の短
波長化が必要であるのに対し、この波長領域では実用的
な硝材が存在しないので、ウエハ198に０．１５μｍ以
下のパターンを形成することができなかった。As described above, in the conventional projection exposure method and projection exposure apparatus, it is necessary to shorten the exposure wavelength to about 150 nm or less in order to form a pattern of 0.15 μm or less on the wafer 198. On the other hand, in this wavelength region, there is no practical glass material, so that a pattern of 0.15 μm or less could not be formed on the wafer 198.
【００１５】米国特許第５，４１５，８３５号公報は2
光束干渉露光によって微細パターンを形成する技術を開
示しており、2光束干渉露光によれば、ウエハに０．１
５μｍ以下のパターンを形成することができる。US Pat. No. 5,415,835 discloses that
A technique for forming a fine pattern by light beam interference exposure is disclosed.
A pattern of 5 μm or less can be formed.
【００１６】2光束干渉露光は、レーザからの可干渉性
を有し且つ平行光線束であるレーザ光をハーフミラーに
よって2光束に分割し、2光束を夫々平面ミラーによって
反射することにより2個のレーザ光（可干渉性平行光線
束）を0より大きく９０度未満のある角度を成して交差
させることにより交差部分に干渉縞を形成し、この干渉
縞（の光強度分布）によってウエハのレジストを露光し
て感光させることで干渉縞の光強度分布に応じた微細な
周期パタ−ン（露光量分布）をウエハ（レジスト）に形
成するものである。In the two-beam interference exposure, a laser beam having a coherence from a laser and being a parallel beam is divided into two beams by a half mirror, and the two beams are reflected by a plane mirror, respectively. The laser beam (coherent parallel light beam) crosses at an angle greater than 0 and less than 90 degrees to form an interference fringe at the intersection, and the interference fringe (light intensity distribution) causes the resist on the wafer Is exposed and exposed to light to form a fine periodic pattern (exposure amount distribution) on the wafer (resist) according to the light intensity distribution of the interference fringes.
【００１７】2光束がウエハ面の立てた垂線に対して互
いに逆方向に同じ角度だけ傾いた状態でウエハ面で交差
する場合、この2光束干渉露光における解像度Rは次の
（３）式で表される。If the two light beams intersect on the wafer surface in the direction opposite to the vertical line of the wafer surface at the same angle in the opposite direction, the resolution R in the two light beam interference exposure is expressed by the following equation (3). Is done.
【００１８】 Ｒ＝λ／（４sinθ） ＝λ／４ＮＡ ＝０．２５（λ／ＮＡ） ……（３） ここで、ＲはＬ＆Ｓ(ライン・アンド・スペース)の夫々
の幅即ち干渉縞の明部と暗部の夫々の幅を、θは2光束
の夫々の像面に対する入射角度（絶対値）を表し、ＮＡ
=sinθである。R = λ / (4 sin θ) = λ / 4NA = 0.25 (λ / NA) (3) where R is the width of each L & S (line and space), that is, the lightness of interference fringes. Represents the width of each of the light and dark portions, and θ represents the angle of incidence (absolute value) of each of the two light beams with respect to each image plane.
= sinθ.
【００１９】通常の投影露光における解像度の式である
(１)式と2光束干渉露光における解像度の式である(３)
式とを比較すると、２光束干渉露光の解像度Ｒは（１）
式においてｋ1 =０．２５とした場合に相当するから、2
光束干渉露光では ｋ1＝０．５〜０．７である通常の投
影露光の解像度より2倍以上の解像度を得ることが可能
である。上記米国特許第５，４１５，８３５号公報には
開示されていないが、例えばλ= ０．２４８ｎｍ（Ｋｒ
Ｆエキシマ）でＮＡ =０．６の時は、Ｒ =０．１０μｍ
が得られる。Expression for resolution in normal projection exposure
Equation (1) and equation for resolution in two-beam interference exposure (3)
Comparing with the equation, the resolution R of the two-beam interference exposure is (1)
Since this corresponds to the case where k 1 = 0.25 in the equation, 2
In the light beam interference exposure, it is possible to obtain a resolution twice or more that of a normal projection exposure in which k 1 = 0.5 to 0.7. Although not disclosed in the above-mentioned US Pat. No. 5,415,835, for example, λ = 0.248 nm (Kr
F = Excimer), when NA = 0.6, R = 0.10 μm
Is obtained.
【００２０】[0020]
【発明が解決しようとする課題】しかしながら2光束干
渉露光は、基本的に干渉縞の光強度分布（露光量分布）
に相当する単純な縞パターンしか得られないので、所望
の形状の回路パタ−ンをウエハに形成することができな
い。However, two-beam interference exposure is basically based on the light intensity distribution (exposure amount distribution) of interference fringes.
Therefore, a circuit pattern having a desired shape cannot be formed on the wafer because only a simple stripe pattern corresponding to the above is obtained.
【００２１】そこで上記米国特許第５，４１５，８３５
号公報は、2光束干渉露光によって単純な縞パターン即
ち2値的な露光量分布をウエハ（のレジスト）に与えた
後、ある開口が形成されたマスクを用いて通常リソグラ
フィー（露光）を行なって更に別の2値的な露光量分布
をウエハに与えることにより孤立の線（パターン）を得
る「多重露光」を提案している。Therefore, the above-mentioned US Pat. No. 5,415,835 is disclosed.
Japanese Patent Application Laid-Open Publication No. H11-216733 discloses a method in which a simple fringe pattern, that is, a binary exposure amount distribution, is given to a wafer (resist) by two-beam interference exposure, and then a normal lithography (exposure) is performed using a mask having a certain opening. We have proposed "multiple exposure" in which an isolated line (pattern) is obtained by giving another binary exposure distribution to the wafer.
【００２２】しかしながら、上記米国特許第５，４１
５，８３５号公報の多重露光の方法は、2光束干渉露光
用の露光装置にウエハを設置して露光した後で、別の通
常露光用の露光装置にウエハを設置し直して露光を行な
うので、時間がかかるという問題があった。However, US Pat.
In the multiple exposure method disclosed in Japanese Patent No. 5,835, the wafer is placed in an exposure apparatus for two-beam interference exposure, and after exposing, the wafer is placed again in another exposure apparatus for normal exposure to perform exposure. There was a problem that it took time.
【００２３】本発明の目的は、比較的短い時間で多重露
光が行なえる露光方法及び露光装置を提供することにあ
る。An object of the present invention is to provide an exposure method and an exposure apparatus capable of performing multiple exposures in a relatively short time.
【００２４】[0024]
【課題を解決するための手段】上記目的を達成するため
に、本発明の第１の露光方法は、同一のマスクパターン
を投影光学系の空間周波数通過スペクトルを変えた形で
照明条件を変えて照明して共通の被露光領域に投影する
ことを特徴とする。In order to achieve the above object, a first exposure method of the present invention changes the illumination condition of the same mask pattern while changing the spatial frequency pass spectrum of the projection optical system. It is characterized by being illuminated and projected onto a common exposure area.
【００２５】本発明の第２の露光方法は、同一のマスク
パターンを投影光学系の空間周波数通過スペクトルを変
えた形で小σ（シグマ）と大σとで照明して共通の被露
光領域に投影することを特徴とする。ここで、σは、照
明光学系のマスク側の開口数を投影光学系のマスク側の
開口数で割った値である。According to the second exposure method of the present invention, the same mask pattern is illuminated with a small σ (sigma) and a large σ while changing the spatial frequency pass spectrum of the projection optical system, so that the same mask pattern is exposed. It is characterized by projecting. Here, σ is a value obtained by dividing the numerical aperture on the mask side of the illumination optical system by the numerical aperture on the mask side of the projection optical system.
【００２６】本発明の第３の露光方法は、同一のマスク
パターンを投影光学系の空間周波数通過スペクトルを変
えた形で小ＮＡ（開口数）と大ＮＡとで照明して共通の
被露光領域に投影することを特徴とする。ここで、ＮＡ
は照明光学系のマスク側の開口数である。According to a third exposure method of the present invention, the same mask pattern is illuminated with a small NA (numerical aperture) and a large NA while changing the spatial frequency transmission spectrum of the projection optical system to form a common exposure area. Is projected on the image. Where NA
Is the numerical aperture on the mask side of the illumination optical system.
【００２７】本発明の第４の露光方法は、同一のマスク
パターンに投影光学系の空間周波数通過スペクトルを変
えた形で斜め照明と垂直照明を行なって共通の被露光領
域に投影することを特徴とする。ここで、斜め照明とは
投影光学系の光軸に対して傾いた方向から照明する形態
であり、垂直照明とは投影光学系の光軸に平行な方向か
ら照明する形態である。The fourth exposure method of the present invention is characterized in that oblique illumination and vertical illumination are performed on the same mask pattern while changing the spatial frequency pass spectrum of the projection optical system, and the same mask pattern is projected onto a common exposure area. And Here, the oblique illumination is a form in which illumination is performed from a direction inclined with respect to the optical axis of the projection optical system, and the vertical illumination is a form in which illumination is performed from a direction parallel to the optical axis of the projection optical system.
【００２８】本発明の第１の露光装置は、同一のマスク
パターンを投影光学系の空間周波数通過スペクトルを変
えた形で照明条件を変えて照明して共通の被露光領域に
投影する露光モードを有することを特徴とする。The first exposure apparatus of the present invention provides an exposure mode in which the same mask pattern is illuminated under different illumination conditions while changing the spatial frequency transmission spectrum of the projection optical system, and is projected onto a common exposure area. It is characterized by having.
【００２９】本発明の第２の露光装置は、同一のマスク
パターンを投影光学系の空間周波数通過スペクトルを変
えた形で小σ（シグマ）と大σとで照明して共通の被露
光領域に投影する露光モードを有することを特徴とす
る。ここで、σは、照明光学系のマスク側の開口数を投
影光学系のマスク側の開口数で割った値である。The second exposure apparatus of the present invention illuminates the same mask pattern with small sigma (sigma) and large sigma while changing the spatial frequency pass spectrum of the projection optical system to form a common exposure area. It has an exposure mode for projecting. Here, σ is a value obtained by dividing the numerical aperture on the mask side of the illumination optical system by the numerical aperture on the mask side of the projection optical system.
【００３０】本発明の第３の露光装置は、同一のマスク
パターンを投影光学系の空間周波数通過スペクトルを変
えた形で小ＮＡ（開口数）と大ＮＡとで照明して共通の
被露光領域に投影する露光モードを有することを特徴と
する。ここで、ＮＡは照明光学系のマスク側の開口数で
ある。A third exposure apparatus according to the present invention illuminates the same mask pattern with a small NA (numerical aperture) and a large NA in a manner that changes the spatial frequency transmission spectrum of the projection optical system, to form a common exposure area. Characterized by having an exposure mode for projecting to Here, NA is the numerical aperture on the mask side of the illumination optical system.
【００３１】本発明の第４の露光装置は、同一のマスク
パターンに投影光学系の空間周波数通過スペクトルを変
えた形で斜め照明と垂直照明を行なって共通の被露光領
域に投影する露光モードを有することを特徴とする。The fourth exposure apparatus of the present invention provides an exposure mode in which oblique illumination and vertical illumination are performed on the same mask pattern while changing the spatial frequency transmission spectrum of the projection optical system, and the same mask pattern is projected onto a common exposure area. It is characterized by having.
【００３２】上記の本発明の露光方法及び露光装置によ
れば、ある露光装置（例えばステップアンドリピート方
式やステップアンドスキャン方式の縮小投影露光装置）
にあるマスクを配置し、このマスクのパターン（同一の
マスクパターン）に対してこの露光装置に異なる照明条
件を設定することで多重露光が行なえるので、従来の２
台の異なる露光装置を用いるう場合に比べて多重露光に
要する時間が短くなる。According to the above-described exposure method and exposure apparatus of the present invention, a certain exposure apparatus (eg, a step-and-repeat type or step-and-scan type reduced projection exposure apparatus)
In the exposure apparatus, different exposure conditions are set for this mask pattern (the same mask pattern), so that multiple exposure can be performed.
The time required for multiple exposures is shorter than when using different exposure apparatuses.
【００３３】尚、上記の小σと大σの意味は各シグマの
大きさの相対的な関係を意味しているだけであり、「あ
るσとこのσより大きい（或いは小さい）σ」を意味す
る。同様に、上記の小ＮＡと大ＮＡの意味は各ＮＡの大
きさの相対的な関係を意味しているだけであり、「ある
ＮＡとこのσより大きい（或いは小さい）ＮＡ」を意味
する。The meaning of the small σ and the large σ only means the relative relationship between the sizes of the respective sigma, and means “a certain σ and a σ larger (or smaller) than this σ”. I do. Similarly, the meaning of the small NA and the large NA only means the relative relationship between the sizes of the respective NAs, and means "a certain NA and an NA larger (or smaller) than σ".
【００３４】本発明は、KrFエキシマレーザー（波長約2
48nm）、ArFエキシマレーザー（波長約193nm）又はF2エ
キシマレーザー（波長約157nm）から光で前記マスクパ
ターンを照明する形態を含む。The present invention relates to a KrF excimer laser (wavelength of about 2
48 nm), the form of illuminating the mask pattern with light from an ArF excimer laser (wavelength: about 193 nm) or an F2 excimer laser (wavelength: about 157 nm).
【００３５】本発明は、屈折系、反射−屈折系、又は反
射系のいずれかより成る投影光学系によって前記マスク
パターンを投影する形態を含む。The present invention includes a mode in which the mask pattern is projected by a projection optical system including any one of a refraction system, a reflection-refraction system, and a reflection system.
【００３６】本発明は、前記被露光領域を途中で現像す
ることなく各照明条件で順次露光する形態を含む。The present invention includes a mode in which the exposed area is sequentially exposed under each illumination condition without being developed on the way.
【００３７】本発明は、前記被露光領域を前記各照明条
件で各照明条件における光が互いに干渉しない状態で
（例えばそれぞれ直線偏光光として互いに偏光方向を直
交させる等した状態）同時に露光する形態を含む。According to the present invention, there is provided an embodiment in which the exposure area is simultaneously exposed under the above-mentioned illumination conditions in such a manner that the lights under the respective illumination conditions do not interfere with each other (for example, the polarization directions are orthogonal to each other as linearly polarized light). Including.
【００３８】本発明は、前記マスクパターンは、使用す
る露光装置の解像限界以下の線幅（例えば０．１μｍ付
近）を持つ開口パターンを有する形態を含む。The present invention includes an embodiment in which the mask pattern has an opening pattern having a line width (for example, around 0.1 μm) smaller than the resolution limit of the exposure apparatus to be used.
【００３９】本発明は、前記開口パターンは複数個並ん
でいる（所謂繰り返しパターンである）形態を含む。The present invention includes a form in which a plurality of the opening patterns are arranged (a so-called repetitive pattern).
【００４０】本発明は、前記マスクパターンは例えばレ
ベンソン型の位相シフトパターンやリム型の位相シフト
パターンを有する形態を含む。The present invention includes an embodiment in which the mask pattern has, for example, a Levenson type phase shift pattern or a rim type phase shift pattern.
【００４１】本発明は、前記投影光学系の空間周波数通
過スペクトルを変えるために前記投影光学系の開口絞り
の開口形状及び／又は透過率分布を変える形態を含む。The present invention includes a mode in which the aperture shape and / or transmittance distribution of the aperture stop of the projection optical system is changed in order to change the spatial frequency transmission spectrum of the projection optical system.
【００４２】本発明は、上記の露光方法や露光装置及び
各形態を用いてデバイスパターンでウエハを露光する段
階と、露光したウエハを現像する段階とを有することを
特徴とするデバイス製造方法が提供できる。According to the present invention, there is provided a device manufacturing method comprising the steps of exposing a wafer with a device pattern using the above-described exposure method, exposure apparatus and each mode, and developing the exposed wafer. it can.
【００４３】[0043]
【発明の実施の形態】本発明の第1の実施形態を説明す
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described.
【００４４】第１の実施形態の従来技術に対する改良点
は投影露光装置において照明光学系の照明条件と投影光
学系の開口絞りとを切り替えることにある。An improvement of the first embodiment over the prior art is that the projection exposure apparatus switches between the illumination condition of the illumination optical system and the aperture stop of the projection optical system.
【００４５】本実施形態は、投影露光装置は従来から照
明条件切替機構や開口絞り切換え機構を有しているの
で、本実施形態を実施するための装置の改良は小規模で
済むという利点がある。また、多重露光に使用するマス
クは、従来と同様のパターンニングを行なった又は若干
の改良を施した、基本的に一枚のマスクであるため、作
成コストがあまりかからない。The present embodiment has the advantage that the projection exposure apparatus conventionally has an illumination condition switching mechanism and an aperture stop switching mechanism, so that the apparatus for implementing this embodiment can be improved on a small scale. . In addition, the mask used for multiple exposure is basically a single mask that has been subjected to patterning similar to that of the related art or has been slightly improved, and therefore does not require much production cost.
【００４６】本実施形態では、専用の２光束干渉計を使
用しないことは勿論投影露光装置に２光束干渉専用のレ
ベンソン型位相シフトマスクのように特殊なマスクを設
置することなく、ウエハに転写すべき回路パターンが形
成された通常のマスクに対して照明光学系の照明条件と
投影光学系の開口絞りの形態を適宜設定することにより
擬似的に「２光束干渉（微細な干渉縞の形成）」を達成
する。In the present embodiment, the transfer to the wafer is performed without using a special mask such as a Levenson-type phase shift mask dedicated to two-beam interference in the projection exposure apparatus as well as not using a dedicated two-beam interferometer. By appropriately setting the illumination conditions of the illumination optical system and the form of the aperture stop of the projection optical system with respect to a normal mask on which a circuit pattern to be formed is formed, pseudo "two-beam interference (formation of fine interference fringes)" To achieve.
【００４７】本実施形態の多重露光の原理は、照明条件
によるマスクパターンの空間周波数スペクトルの制御と
投影光学系の開口絞りによるマスクパターンの空間周波
数スペクトルの制御を組み合わせることによって、マス
クから２光束干渉が実質的に生じるような空間周波数成
分を抽出してマスクに含まれる通常の露光では解像でき
ない極微細な線パターン（の繰り返しパターン）を当該
パターンに最適な当該２光束干渉によって独立にウエハ
のレジストを露光してそこに周期的な潜像を形成する一
方、同一のマスクパターンでウエハのレジストに通常の
露光を行なった結果の潜像を重ねて形成し（潜像形成の
順番は逆でも可）、積算された潜像（積算された露光量
分布）を元に現像を行って所望の回路パターンを得ると
いうものである。The principle of the multiple exposure according to the present embodiment is that the control of the spatial frequency spectrum of the mask pattern by the illumination condition and the control of the spatial frequency spectrum of the mask pattern by the aperture stop of the projection optical system are combined, so that the two-beam interference from the mask is achieved. Is extracted by extracting a spatial frequency component that substantially causes a pattern (a repetition pattern) that cannot be resolved by the normal exposure included in the mask and is independently formed on the wafer by the two-beam interference optimal for the pattern. The resist is exposed and a periodic latent image is formed thereon, and a latent image obtained by performing normal exposure on the resist on the wafer with the same mask pattern is formed on the resist (the latent image is formed in the reverse order). Yes), a desired circuit pattern is obtained by performing development based on the accumulated latent image (accumulated exposure amount distribution).
【００４８】この多重露光法によれば、１マスク内に含
まれる多様な微細パターンをそれぞれ投影露光装置の限
界能力を用いて露光可能となり、単純な一露光で制限さ
れていた投影露光装置の能力を最大限引き出すことがで
きる。According to this multiple exposure method, various fine patterns included in one mask can be exposed using the limit capability of the projection exposure apparatus, and the performance of the projection exposure apparatus which has been limited by one simple exposure Can be maximized.
【００４９】例えば、KrFエキシマレーザ（波長約248n
m）と像側の開口数（ＮＡ）０．６の投影レンズ系とを
用いた投影露光装置で、線幅０．１μｍのパターン
（像）をシリコンウエハのレジスト上の露光（潜像形
成）することも可能であり、この線幅は現在この種の装
置の限界とされている最小焼付け線幅０．２μｍの１／
２の線幅であり、約2倍の解像度が得られることにな
る。For example, a KrF excimer laser (wavelength: about 248 nm)
m) and a projection exposure system using a projection lens system having an image-side numerical aperture (NA) of 0.6, exposing a pattern (image) having a line width of 0.1 μm on a silicon wafer resist (latent image formation) It is also possible to make the line width 1/1/2 of the minimum printing line width 0.2 μm which is currently a limit of this type of apparatus.
This is a line width of 2, which means that about twice the resolution can be obtained.
【００５０】図２に本多重露光法の基本的なフロ−チャ
−トを示す。FIG. 2 shows a basic flowchart of the present multiple exposure method.
【００５１】図２に示すとおり、本多重露光法は、ラフ
（粗）露光ステップ，ファイン（微細）露光ステップを
含む。ラフ露光ステップとファイン露光ステップは図２
の逆の順番で行なっても良く、少なくとも一方のステッ
プに複数回の露光ステップがある場合は、ラフ露光ステ
ップとファイン露光ステップを交互に行う方法もある。
ラフ露光とファイン露光の間で現像はしない。As shown in FIG. 2, the present multiple exposure method includes a rough (coarse) exposure step and a fine (fine) exposure step. The rough and fine exposure steps are shown in FIG.
May be performed in the reverse order. If at least one of the steps includes a plurality of exposure steps, there is a method of alternately performing the rough exposure step and the fine exposure step.
No development is performed between rough exposure and fine exposure.
【００５２】また、各露光ステップ間には公知のウエハ
アライメントステップ等を適宜挿入して像形成精度を上
げる方法がある。このように本発明は図２のものにその
手順や構成が限定されるものではない。There is also a method in which a well-known wafer alignment step or the like is appropriately inserted between each exposure step to increase image forming accuracy. As described above, the present invention is not limited to the procedure and configuration shown in FIG.
【００５３】図２が示す手順に従って多重露光を行なう
場合、あるマスクのパターン（マスクパターン）と投影
露光装置を用いてまずラフ露光を行い、ウエハ等の感光
基板をマスクパターンの像で露光する（レジストに潜像
を形成する）。本実施形態は投影光学系で解像できる最
小線幅以下の極微細な線幅の像を感光基板に露光するも
のであるため、マスクパターンは最小線幅以下の線幅に
対応するパターンを含んでいる。このようなマスクパタ
ーンの一例を図３に示す。When multiple exposure is performed according to the procedure shown in FIG. 2, rough exposure is first performed using a mask pattern (mask pattern) and a projection exposure apparatus, and a photosensitive substrate such as a wafer is exposed with a mask pattern image ( A latent image is formed on the resist). In the present embodiment, since an image having an extremely fine line width smaller than the minimum line width that can be resolved by the projection optical system is exposed on the photosensitive substrate, the mask pattern includes a pattern corresponding to a line width smaller than the minimum line width. In. FIG. 3 shows an example of such a mask pattern.
【００５４】図３のパターンは半導体デバイスのASICに
用いられる所謂ゲートパターンである。図３中、３１は
ゲート線で、スイッチングを司る主要部分であり、この
ゲート線の線幅に極微細化が望まている。一方、３２は
配線コンタクト部で、この部分３２はある程度の面積が
必要であるため、ゲート線３１に比べて寸法が大きなパ
ターンとなっている。従って、このゲートパターンは投
影光学系で解像できる最小線幅以下の像に対応する微細
な線パターンとそれに比べて大きめのパターンとが混在
している。そのためラフ露光（投影露光）ステップでは
おおきめのパターンは解像されるが微細線パターンは解
像されない。またその際の焦点深度は浅い。The pattern shown in FIG. 3 is a so-called gate pattern used for an ASIC of a semiconductor device. In FIG. 3, reference numeral 31 denotes a gate line, which is a main part that controls switching, and it is desired that the line width of the gate line be extremely fine. On the other hand, reference numeral 32 denotes a wiring contact portion, and since this portion 32 requires a certain area, the pattern has a larger size than the gate line 31. Therefore, this gate pattern includes both a fine line pattern corresponding to an image having a size smaller than the minimum line width that can be resolved by the projection optical system and a pattern larger than that. Therefore, in the rough exposure (projection exposure) step, a large pattern is resolved, but a fine line pattern is not resolved. The depth of focus at that time is shallow.
【００５５】次にラフ露光を行った感光基板の同一領域
（共通領域）に対して、現像を行なわずにファイン露光
を行なって、同一領域のレジストを微細線パターンの像
で露光することいよって多重露光を完了するが、本実施
形態のファイン露光は、マスクをそのままにして同一の
マスクパターンを対象に、マスクを照明する照明光学系
の照明条件とマスクパターンを投影する投影光学系の開
口絞りの形態を（ラフ露光の場合に対して）変更した後
で行うところが特徴である。Next, fine exposure is performed on the same region (common region) of the photosensitive substrate that has been subjected to the rough exposure, without performing development, and the resist in the same region is exposed with a fine line pattern image. Although the multiple exposure is completed, the fine exposure according to the present embodiment is performed by using the same mask pattern as the target while leaving the mask as it is, and the illumination conditions of the illumination optical system that illuminates the mask and the aperture stop of the projection optical system that projects the mask pattern. Is performed after changing the form (for rough exposure).
【００５６】図４に、本実施形態のラフ露光とファイン
露光のそれぞれで設定される有効光源の形状（照明光学
系の開口絞りを投影光学系の開口絞りの開口に投影した
の像の形状）と投影光学系の開口絞りの開口形状とマス
クとウエハ上の像とを示す。FIG. 4 shows the shape of the effective light source (the shape of the image obtained by projecting the aperture stop of the illumination optical system onto the aperture of the aperture stop of the projection optical system) which is set for each of the rough exposure and the fine exposure in this embodiment. 2 shows an aperture shape of an aperture stop of a projection optical system, a mask, and an image on a wafer.
【００５７】図４に示す通り、本実施形態では、同一の
マスクパターンに対して、ラフ露光の際はσ＝０．８程
度の有効光源を形成する垂直照明法（通常の照明法）を
用いいると共に投影光学系の開口絞りとして通常の円形
の開口を備える絞りを用い、ファイン露光の際は2重極
の（σ＝０．２程度の円形光源が一対光軸に関して対称
にマスクパターンであるゲートパターンアレイの微細線
パターンの繰り返し方向であるｘ方向に並ぶ）有効光源
を形成するような斜め照明法を用いると共に投影光学系
の開口絞りとしてマスクパターンであるゲートパターン
アレイの微細線パターンの繰り返し方向であるｘ方向に
長い長方形の開口を備える絞りを用い、ラフとファイン
の多重露光を行なう。尚、図４中のｘ軸とｙ軸の各方向
は図３のゲートパターン中に示したｘ軸とｙ軸の各方向
と揃えてある。As shown in FIG. 4, in the present embodiment, a vertical illumination method (ordinary illumination method) for forming an effective light source of about σ = 0.8 is used for the same mask pattern at the time of rough exposure. In addition, an aperture stop having an ordinary circular aperture is used as an aperture stop of the projection optical system, and in the case of fine exposure, a dipole (a circular light source of about σ = 0.2) is a mask pattern symmetrically with respect to a pair of optical axes. (In the x direction, which is the repetition direction of the fine line pattern of the gate pattern array) Use an oblique illumination method that forms an effective light source, and repeat the fine line pattern of the gate pattern array that is a mask pattern as an aperture stop of the projection optical system. Rough and fine multiple exposure is performed using a stop having a rectangular opening that is long in the x direction, which is the direction. Note that the x-axis and y-axis directions in FIG. 4 are aligned with the x-axis and y-axis directions shown in the gate pattern of FIG.
【００５８】このような多重露光を行った時の各パター
ン像の光強度分布（断面）図の一例を図５に示す。図５
は具体的には図３に示したゲートパターンのゲート線の
中央部のA-A'断面の光強度分布を示している。図５にお
いて、上段はネガレジストに対する露光、下段はポジレ
ジストに対する露光の結果を示し、各段左から順にラフ
露光の結果、ファイン露光の結果、そしてラフとファイ
ンの二露光の積算結果を示している。FIG. 5 shows an example of a light intensity distribution (cross section) of each pattern image when such multiple exposure is performed. FIG.
Specifically, FIG. 3 shows the light intensity distribution on the AA ′ cross section at the center of the gate line of the gate pattern shown in FIG. In FIG. 5, the upper row shows the result of exposure to the negative resist, the lower row shows the result of exposure to the positive resist, the result of rough exposure, the result of fine exposure, and the integration result of two exposures of rough and fine in order from the left of each row. I have.
【００５９】図５より、ラフ露光だけではゲート線を形
成できる許容露光量の幅(露光裕度)が狭いのに対し、二
露光（多重露光）ではファイン露光によりコントラスト
の大きいゲート線パターンの光強度分布が積算されるこ
とによって許容露光量の幅がネガレジストに対する露光
で約２倍、ポジレジストに対する露光では約３倍に拡大
されていることがわかる。FIG. 5 indicates that the width of the allowable exposure amount (exposure allowance) for forming a gate line is narrow only by rough exposure, whereas the light of a gate line pattern having a large contrast is obtained by fine exposure in two exposures (multiple exposure). By integrating the intensity distributions, it can be seen that the width of the permissible exposure amount is increased about twice in exposure to a negative resist and about three times in exposure to a positive resist.
【００６０】即ち本実施形態の多重露光により露光装置
の通常の解像限界よりも解像度の高い（線幅の狭い）パ
ターンの像で被露光基板のレジストを安定して露光し感
光させる（潜像を形成させる）ことが可能となる。That is, the resist on the substrate to be exposed is stably exposed and exposed to light with a pattern image having a higher resolution (narrower line width) than the normal resolution limit of the exposure apparatus by the multiple exposure of this embodiment (latent image). Is formed).
【００６１】図１４で本実施形態のファイン露光で用い
た斜め照明法に基く結像の効果を説明する。FIG. 14 illustrates the effect of image formation based on the oblique illumination method used in the fine exposure according to the present embodiment.
【００６２】図１４中、(A)が通常の露光装置の通常の
使用状態で最小線幅のパターンを露光する様子、(B)が
通常の使用状態で限界解像の２倍の周波数のパターンを
露光する様子、(C)が本実施形態の斜め照明法で２倍の
周波数のパターンを露光する様子、を示す摸式図であ
る。In FIG. 14, (A) shows a state of exposing a pattern having a minimum line width in a normal use state of a normal exposure apparatus, and (B) shows a pattern of a frequency twice as high as the limit resolution in a normal use state. FIG. 4C is a schematic diagram showing a state in which a pattern having twice the frequency is exposed by the oblique illumination method of the present embodiment.
【００６３】図１４(A)では、マスク１４１上の線の繰
り返しパターン１４３のピッチP1に対応する1次回折光
が投影光学系の開口絞りの開口にぎりぎり入る状態とな
っている．即ち，投影光学系を通過して結像に寄与する
光はマスクを素通りする０次光と正負の１次回折光との
3光束である。尚、図１４中、１４２はガラス基板であ
る。In FIG. 14A, the first-order diffracted light corresponding to the pitch P1 of the line repetition pattern 143 on the mask 141 is almost in the state of entering the aperture stop of the projection optical system. That is, the light that passes through the projection optical system and contributes to the image formation is a combination of the zero-order light and the positive and negative first-order diffracted light that pass through the mask.
3 luminous flux. In FIG. 14, reference numeral 142 denotes a glass substrate.
【００６４】図１４(B)は、マスク１４１上の線の繰り
返しパターン１４３のピッチP2を図１４(A)のピッチP1
の１／２としたもので、この場合マスクで回折された１
次回折光の出射角θ２は図１４(A)の場合の出射角θ１
に比べて２倍となる。従って投影光学系の開口絞りの開
口に入るのは０次光のみとなり，即ち投影光学系を通過
して結像に寄与する光はマスクを素通りする０次光だけ
であり、線の像は解像されない。FIG. 14B shows the pitch P2 of the line repetition pattern 143 on the mask 141 as the pitch P1 of FIG.
In this case, 1 is diffracted by the mask.
The output angle θ2 of the next-order diffracted light is the output angle θ1 in the case of FIG.
It is twice as large as. Accordingly, only the 0th-order light enters the aperture of the aperture stop of the projection optical system, that is, the light that passes through the projection optical system and contributes to the image formation is only the 0th-order light that passes through the mask, and the line image is the solution. Not imaged.
【００６５】図１４(C)は、図１４(B)と同じく図１４
(A)のピッチP1の１／２のピッチのパターン１４３を用
いるが，入射光を投影光学系の光軸に対して傾けて斜入
射照明とした場合であり、入射光の入射角θ３は図１４
(B)の出射角θ２の１／２としている。この場合図示す
るように０次光と正負の １次回折光の進行方向がそれ
ぞれ斜め方向に同じ側にシフトするので、正負の１次回
折光の内のどちらか一方の１次回折光（図は−１次の場
合を示している）と０次光とが投影光学系の開口絞りの
開口に入り、２光束が投影光学系を通過して結像に寄与
する。FIG. 14C is the same as FIG.
A pattern 143 having a pitch １ ／ of the pitch P1 of (A) is used, but the incident light is inclined with respect to the optical axis of the projection optical system to provide oblique illumination, and the incident angle θ3 of the incident light is shown in FIG. 14
(B) is の of the emission angle θ2. In this case, as shown in the figure, the traveling directions of the zero-order light and the positive and negative first-order diffracted lights are each shifted obliquely to the same side, so that either one of the positive and negative first-order diffracted lights (in the figure, -1) The following case is shown) and the zero-order light enters the aperture of the aperture stop of the projection optical system, and the two light beams pass through the projection optical system and contribute to image formation.
【００６６】従って線の像は解像される。この２光束干
渉による結像において０次光と１次回折光が結像面で成
す角度は図１４(A)の通常照明の場合の３光束干渉の角
度の２倍であり、従って解像度は図１４(A)の場合の２
倍となる。Accordingly, the image of the line is resolved. In the image formed by the two-beam interference, the angle formed by the zero-order light and the first-order diffracted light on the image plane is twice the angle of the three-beam interference in the case of the normal illumination shown in FIG. 2 in case of (A)
Double.
【００６７】以上の説明は１次元的な見方であり、もし
マスクが微細な線露光専用で１次元の周期パターン（繰
り返しパターン）だけ形成してあれば上記の斜入射照明
によって微細な線を露光することが可能であるが、一般
的なマスクはパターンの方向性が２次元であり投影光学
系の開口絞りは円形開口を備えているため、マスクから
の光は円形開口内で２次元的に分布し、斜入射照明を行
っても図１４(C)で説明した２光束干渉の解像度が通常
の２倍という利点が得られない。The above description is a one-dimensional view. If the mask is dedicated to fine line exposure and only a one-dimensional periodic pattern (repeated pattern) is formed, fine lines are exposed by the above-mentioned oblique incidence illumination. However, since the general mask has a two-dimensional pattern direction and the aperture stop of the projection optical system has a circular aperture, light from the mask is two-dimensionally transmitted within the circular aperture. Even if distributed and oblique incidence illumination is performed, the advantage that the resolution of the two-beam interference described in FIG.
【００６８】このことから、本実施形態はゲートパター
ン等の回路パターンに含まれる微細な線パターンを解像
度が通常の２倍或いはそれに近い条件で露光するのが目
的であるのので、図１４の構成による通常の一回露光で
は目的を完全に達成できないことが分かる。From this, the present embodiment aims at exposing a fine line pattern included in a circuit pattern such as a gate pattern under the condition that the resolution is twice or more the normal resolution, and therefore, the configuration of FIG. It can be understood that the object cannot be completely achieved by the normal single exposure by the method described above.
【００６９】そこで本願発明者は鋭意検討を重ね、同一
パターンに対して大σの垂直照明と小σの斜め照明を行
なう多重露光を採用するだけでなく、斜め照明の際に投
影光学系の開口絞りとして解像限界以下の微細な線から
の回折光を選択的に通過させる長方形状の開口を有する
絞りを配置することによって目的を達成した。The inventor of the present invention has conducted intensive studies and has not only employed multiple exposure for performing a large σ vertical illumination and a small σ oblique illumination for the same pattern, but also employed an aperture of a projection optical system for oblique illumination. The object is achieved by arranging a stop having a rectangular opening through which diffracted light from a fine line smaller than the resolution limit is selectively passed as the stop.
【００７０】本発明の露光装置の一実施例を図１に示
す。FIG. 1 shows an embodiment of the exposure apparatus of the present invention.
【００７１】図１において、１１は露光用の光源であ
り、KrFエキシマレーザー（波長約248nm）、ArFエキシ
マレーザー（波長約193nm）又はF2エキシマレーザー
（波長約157nm）が使用できる。これらのレーザーは必
要に応じて共振器内に分光素子を配置して狭帯域化レー
ザーとして用いられる。In FIG. 1, reference numeral 11 denotes a light source for exposure, and a KrF excimer laser (wavelength: about 248 nm), an ArF excimer laser (wavelength: about 193 nm), or an F2 excimer laser (wavelength: about 157 nm) can be used. These lasers are used as narrow-band lasers by disposing a spectroscopic element in a resonator as necessary.
【００７２】１２は照明光学系、１３は照明光学系１２
の照明モ−ドの摸式図、１４は回路パターンが形成され
たマスク、１５は照明光学系の開口絞り交換手段、１６
は交換用開口絞り、１７はレチクルステ−ジ、１８は投
影光学系で、屈折系、反射−屈折系、又は反射系のいず
れかより成る。Reference numeral 12 denotes an illumination optical system, and 13 denotes an illumination optical system 12.
14 is a schematic diagram of the illumination mode, 14 is a mask on which a circuit pattern is formed, 15 is an aperture stop replacing means of an illumination optical system, 16
Is a replacement aperture stop, 17 is a reticle stage, and 18 is a projection optical system, which is one of a refraction system, a reflection-refraction system, and a reflection system.
【００７３】１９は投影光学系の開口絞り、２０は投影
光学系の開口絞り交換手段、２１は感光基板であるとこ
ろのレジスト付シリコンウエハ、２２はウエハ２１を保
持して投影光学系１８の光軸方向及びこの光軸方向に垂
直な平面に沿って２次元的に移動するウエハステ−ジで
ある。Reference numeral 19 denotes an aperture stop of the projection optical system, reference numeral 20 denotes an aperture stop replacement unit of the projection optical system, reference numeral 21 denotes a silicon wafer with a resist serving as a photosensitive substrate, and reference numeral 22 denotes light of the projection optical system 18 holding the wafer 21. This is a wafer stage that moves two-dimensionally along an axial direction and a plane perpendicular to the optical axis direction.
【００７４】この露光装置はステップアンドリピート方
式やステップアンドスキャン方式でウエハ２１の多数の
ショット領域にマスク１４の回路パターンを縮小投影露
光する装置である。This exposure apparatus is an apparatus that performs a reduced projection exposure of a circuit pattern of the mask 14 on a large number of shot areas of the wafer 21 by a step-and-repeat method or a step-and-scan method.
【００７５】この露光装置で前述のラフ露光を行なう場
合は、マスク１４に対し、照明モード図１３中(1)で示
したように通常の部分コヒーレント垂直照明即ち照明光
学系１２で大ＮＡ、大σ(σ＝０．６〜０．８程度)の円
形開口を持つ開口絞り(1)を用いると共に投影光学系１
８で径が略最大の円形開口を持つ開口絞り(1)'を用い
て、マスク１４のパターンをウエハ２のレジストに結像
させる。When the above-described rough exposure is performed by this exposure apparatus, the mask 14 is subjected to ordinary partial coherent vertical illumination, ie, the illumination optical system 12 with a large NA and large illumination mode, as shown in FIG. An aperture stop (1) having a circular aperture of σ (σ = about 0.6 to 0.8) is used, and the projection optical system 1 is used.
The pattern of the mask 14 is imaged on the resist of the wafer 2 by using an aperture stop (1) 'having a circular aperture having a diameter which is substantially the maximum in FIG.
【００７６】次に、この露光装置で前述のファイン露光
を行う場合は、ラフ露光と同一のマスク１４に対し、マ
スク１４とウエハ２１は基本的にそのままで、照明モー
ド図１３中(2)で示したように小ＮＡ、小σ（σ＝０．
１〜０．３程度）の斜入射照明即ち照明光学系１２で開
口絞り(2)を用いると共に投影光学系１８の開口で絞り
については斜入射照明により開口絞り位置で０次光と１
次回折光が並ぶ方向（換言すればマスク１４の微細な線
の繰り返し方向）に長手方向を持つ長方形の開口を備え
る開口絞り(2)'を用いて、マスク１４のパターンをウエ
ハ２１の同一（共通の）領域に結像させてる。Next, when the above-described fine exposure is performed by this exposure apparatus, the mask 14 and the wafer 21 are basically kept as they are with respect to the same mask 14 as the rough exposure, and the illumination mode in FIG. As shown, small NA, small σ (σ = 0.
(Approximately 1 to 0.3) oblique incidence illumination, that is, an aperture stop (2) is used in the illumination optical system 12, and the aperture at the aperture of the projection optical system 18 is obliquely incident illumination and 0th order light and 1 at the aperture stop position
By using an aperture stop (2) ′ having a rectangular opening having a longitudinal direction in the direction in which the next diffracted light is arranged (in other words, the repetition direction of the fine lines of the mask 14), the pattern of the mask 14 Image).
【００７７】照明光学系１２の開口絞り(1)と(2)は開口
絞り交換手段１６により交換し，投影光学系の１８の開
口絞り(1)'と(2)'は開口絞り交換手段２０によって交換
する。The aperture stops (1) and (2) of the illumination optical system 12 are exchanged by the aperture stop exchange means 16, and the aperture stops (1) 'and (2)' of the projection optical system 18 are exchanged by the aperture stop exchange means 20. Replace by
【００７８】開口絞り交換手段１５としては、図６に示
すように、ファイン露光用とラフ露光用の２つの開口絞
り（フィルタ）６３、６４を1つの保持具６１に固定し
ておき、この保持具６１を照明光学系１２の光軸に垂直
な方向に平行にスライドさせて一方の開口絞りを選択的
に照明光学系１２の光路６２内に配置する手段や、図７
に示すように、複数の開口絞り（フィルタ）７３−７７
を円盤状の保持具７１（ターレット）に固定しておき、
この保持具７１を照明光学系１２の光軸に垂直な面内で
回転させて一つの開口絞りを選択的に照明光学系１２の
光路７２内に配置する手段等がある。As the aperture stop changing means 15, as shown in FIG. 6, two aperture stops (filters) 63 and 64 for fine exposure and rough exposure are fixed to one holder 61, and 7, a tool 61 is slid parallel to a direction perpendicular to the optical axis of the illumination optical system 12, and one of the aperture stops is selectively disposed in the optical path 62 of the illumination optical system 12.
As shown in the figure, a plurality of aperture stops (filters) 73-77
Is fixed to a disc-shaped holder 71 (turret),
There is a means for rotating the holder 71 in a plane perpendicular to the optical axis of the illumination optical system 12 to selectively arrange one aperture stop in the optical path 72 of the illumination optical system 12.
【００７９】一方、開口絞り交換手段２０としては、図
８に示すように、長方形開口を備える開口絞り（フィル
タ）８５を不図示の保持具に保持しておき、ファイン露
光時にこの保持具を投影光学系１８の光軸に垂直な方向
に平行にスライドさせて投影光学系１８内の所定位置
（瞳位置）に開口絞り８５挿入して固定し、ラフ露光時
にはこの保持具を平行にスライドさせて保持具ごと開口
絞り８５を投影光学系の光路から退避させる手段や、図
９に示すように投影光学系１８に対して外側より２枚の
遮光板９５を投影光学系１８の光軸に垂直な方向に平行
にスライドさせて光路９６内の所定位置まで挿入して固
定することにより光路の中心部に長方形の開口を形成す
る手段等がある。On the other hand, as shown in FIG. 8, as the aperture stop changing means 20, an aperture stop (filter) 85 having a rectangular aperture is held in a holder (not shown), and this holder is projected during fine exposure. The aperture stop 85 is inserted and fixed at a predetermined position (pupil position) in the projection optical system 18 by being slid parallel to a direction perpendicular to the optical axis of the optical system 18, and the holder is slid in parallel during rough exposure. A means for retracting the aperture stop 85 together with the holder from the optical path of the projection optical system, and two light shielding plates 95 from the outside with respect to the projection optical system 18 perpendicular to the optical axis of the projection optical system 18 as shown in FIG. For example, there is a means for forming a rectangular opening in the center of the optical path by inserting the optical path 96 into a predetermined position in the optical path 96 and fixing it by sliding in parallel to the direction.
【００８０】更に、図１０に示すように機構１０２、１
０３によって図８の手段の保持具や開口絞り８５を駆動
して回転可能にしたり、図９の手段において２枚の遮光
板と遮光板挿入退避手段とを回転可能にしたりして、長
方形開口の方位を変更できるようにする構成を採った
り、長方形開口の方位が異なる複数種の開口絞りと開口
絞り挿入退避交換手段を設けたりする構成を採り、後述
する実施例に用いることもある。Further, as shown in FIG.
By driving the holder and the aperture stop 85 of the means of FIG. 8 by means of the lever 03, the two light-shielding plates and the light-shielding plate insertion / retreat means of the means of FIG. A configuration is adopted in which the orientation can be changed, or a configuration in which a plurality of types of aperture stops having different orientations of the rectangular aperture and an aperture stop insertion / retraction / exchange unit is provided is used in some embodiments described later.
【００８１】前述の実施形態は集積化されたゲートパタ
ーンを２重露光（途中で現像しないで異なる条件で２回
露光する）するものであったが、以下には集積化された
ゲートパターンを３重露光で行なう実施形態を説明す
る。In the above-described embodiment, the integrated gate pattern is subjected to double exposure (exposure is performed twice under different conditions without development in the middle). An embodiment performed by double exposure will be described.
【００８２】本実施形態は図１１に示すようにゲートパ
ターン同志が集積化された場合に、より適した露光方法
および露光装置の一例であり、図１、図７及び図１０が
示す投影露光装置が用いられる。This embodiment is an example of an exposure method and an exposure apparatus which are more suitable when gate patterns are integrated as shown in FIG. 11, and is a projection exposure apparatus shown in FIGS. 1, 7 and 10. Is used.
【００８３】本実施形態では図１２に示すように、２左
のラフ露光と中央のファイン露光1に加えて右のファイ
ン露光２の３重露光を行うことによりによりゲートパタ
ーン像同志のｘｙ方向のそれぞれの分離境界を強調でき
る。In the present embodiment, as shown in FIG. 12, by performing triple exposure of the right fine exposure 2 in addition to the two left rough exposures and the center fine exposure 1, the gate pattern images can be moved in the xy directions. Each separation boundary can be emphasized.
【００８４】本実施形態のラフ露光とファイン露光1は
露光量などに違いはあるものの基本的に前述の図４で説
明した実施形態と同じ露光を行なうが、ファイン露光2
は、２重極有効光源を形成する斜入射照明と長方形開口
の開口絞りによる空間周波数調整（フィルタリング）を
行う点はファイン露光1と同様であるが、マスクパター
ンは維持して、開口絞りの長方形開口の方位を（必要に
応じて有効光源の方位も）ファイン露光1の状態から９
０度回転させて配置して露光を行なう。これによって集
積化されたことで高い解像度が必要となったｙ方向(紙
面上下)の解像度を高め，更に斜入射照明の方向と異な
ることで，より好ましい強度分布を構成している。The rough exposure and the fine exposure 1 of this embodiment are basically the same as those of the embodiment described with reference to FIG.
Is similar to fine exposure 1 in that oblique incidence illumination forming a dipole effective light source and spatial frequency adjustment (filtering) by a rectangular aperture stop are performed, but the mask pattern is maintained and the aperture stop rectangle is Change the direction of the aperture (and the direction of the effective light source if necessary) from the state of fine exposure 1 to 9
Exposure is performed by arranging the device by rotating it by 0 degrees. As a result, the resolution in the y-direction (up and down on the paper surface), for which high resolution is required due to integration, is increased, and further different from the direction of oblique incidence illumination, thereby forming a more favorable intensity distribution.
【００８５】本発明は以上説明した実施例に限定される
ものではなく本発明の趣旨を逸脱しない範囲において露
光シーケンス等も種々に変更する事が可能である。The present invention is not limited to the embodiments described above, and the exposure sequence and the like can be variously changed without departing from the spirit of the present invention.
【００８６】特に照明光学系１２の開口絞りの開口形状
や投影光学系１８の開口絞りの形状はウエハに転写すべ
き回路パターンに合わせて適宜選択される。例えば照明
光学系の開口絞り１６としては輪帯状の開口を持つ絞り
（図７の絞り７７）や光軸外に４つの開口を持つ絞り
（図７の絞り７６）等も使用でき、投影光学系１８の開
口絞り１９としては楕円状開口を持つ絞りや光軸外に４
つの開口を持つ絞り等を用いることができる。これに関
してファイン露光の変形例(1)-(3)を図１３に示す。In particular, the shape of the aperture stop of the illumination optical system 12 and the shape of the aperture stop of the projection optical system 18 are appropriately selected according to the circuit pattern to be transferred to the wafer. For example, as the aperture stop 16 of the illumination optical system, a stop having an annular aperture (a stop 77 in FIG. 7), a stop having four apertures outside the optical axis (a stop 76 in FIG. 7), and the like can be used. As the aperture stop 18, a stop having an elliptical aperture or a 4
An aperture having two openings can be used. FIG. 13 shows modified examples (1) to (3) of the fine exposure.
【００８７】以上説明した各実施形態によれば、通常の
投影露光装置と一枚のマスク或いはそれぞれに若干の改
良を施しただけで、装置の限界解像以下の線幅のパター
ンを有する回路パターンを二重露光や三重露光によって
ウエハに露光できるので、装置間のウエハの移動、マス
クの交換等が不要であり、二重露光や三重露光に要する
時間を短くできる。次に投影光学系１８の開口絞りの開
口形状を換えずにラフ露光とファイン露光を行なう実施
形態を説明する。本実施形態は図1及び図7が示す投影露
光装置により行なう露光方法に関するものである。According to each of the embodiments described above, a circuit pattern having a line width less than the limit resolution of the apparatus can be obtained by making only a slight improvement to the ordinary projection exposure apparatus and one mask or each. Can be exposed on a wafer by double exposure or triple exposure, so that it is not necessary to move the wafer between apparatuses, exchange masks, etc., and the time required for double exposure or triple exposure can be shortened. Next, an embodiment in which rough exposure and fine exposure are performed without changing the aperture shape of the aperture stop of the projection optical system 18 will be described. This embodiment relates to an exposure method performed by the projection exposure apparatus shown in FIGS.
【００８８】本実施形態の特徴は、露光装置の解像限界
以下の線幅の微細な孤立パターンを有する回路パターン
のこの微細な線に補助パターンを付設し、この補助パタ
ーン付回路パターンを、途中で現像を行なわないで、大
σの垂直照明によるラフ露光と小σの斜め照明によるフ
ァイン露光との二重露光を行なう点にあり、ラフ露光で
０．５λ／ＮＡ以上の大き目のパターンを優先的に解像
し、ファイン露光で０．５λ／ＮＡ以下の微細パターン
を優先的に解像する。ここで、λは露光光の波長、ＮＡ
は投影光学系の像面側の開口数である。The feature of this embodiment is that an auxiliary pattern is attached to a fine line of a circuit pattern having a fine isolated pattern having a line width equal to or less than the resolution limit of the exposure apparatus, and the circuit pattern with the auxiliary pattern is inserted in the middle. In that the double exposure of rough exposure with large σ vertical illumination and fine exposure with small σ oblique illumination is performed without performing development, and preferentially a pattern larger than 0.5λ / NA in rough exposure. And fine resolution of 0.5λ / NA or less is preferentially resolved by fine exposure. Here, λ is the wavelength of the exposure light, NA
Is the numerical aperture on the image plane side of the projection optical system.
【００８９】本実施形態の場合、投影光学系１８の開口
絞りはラフ露光とファイン露光の双方で図１の円形開口
を備える開口絞り(1)'を用い、照明光学系１２の切り替
えられる開口絞りとしては、ラフ露光は図７の通常の中
央円形開口を持つ絞り７３、ファイン露光は図７の４つ
の軸外開口を持つ絞り７６や輪帯開口を持つ絞り７７が
用いられる。照明光学系１２のこれらの開口絞りは先の
実施例で述べた方法により切り換えられる。In this embodiment, the aperture stop of the projection optical system 18 uses the aperture stop (1) 'having a circular aperture shown in FIG. For rough exposure, the stop 73 having a normal central circular aperture shown in FIG. 7 is used, and for fine exposure, the stop 76 having four off-axis apertures shown in FIG. These aperture stops of the illumination optical system 12 are switched by the method described in the previous embodiment.
【００９０】図１７は絞り７６の開口像（有効光源）を
示す図、図１８は絞り７７の開口像（有効光源）の図、
図１９は絞り７３の開口像（有効光源）の図であり、こ
れらの開口像は０次光で投影光学系の開口絞りの開口内
（瞳）に形成される。FIG. 17 is a view showing an aperture image (effective light source) of the stop 76, FIG. 18 is a view showing an aperture image (effective light source) of the stop 77,
FIG. 19 is a diagram of an aperture image (effective light source) of the stop 73, and these aperture images are formed in the aperture (pupil) of the aperture stop of the projection optical system with zero-order light.
【００９１】補助パターンの付設の仕方について述べ
る。The way of providing the auxiliary pattern will be described.
【００９２】パターンの幅wが０．５λ／ＮＡ以下の孤
立した微細パターンに対して補助パターンを付ける。こ
の時、片側のみ孤立している微細パターンには孤立して
いる片側のみに補助パターンを付ける。補助パターンの
線幅w'は大凡０．２５λ／ＮＡ以下に設定され、微細パ
ターンと孤立パターンの間隔sは線幅w'と同じ値または
近い値にするのが有効である。An auxiliary pattern is provided for an isolated fine pattern having a pattern width w of 0.5λ / NA or less. At this time, an auxiliary pattern is attached to only one side of the isolated fine pattern. The line width w 'of the auxiliary pattern is set to approximately 0.25λ / NA or less, and it is effective to set the interval s between the fine pattern and the isolated pattern to the same value as or close to the line width w'.
【００９３】尚、微細パターンが繰り返しパターンを構
成している場合や補助パターンを付設できないくらい多
数密集している場合には、補助パターンは付けない。When the fine patterns form a repetitive pattern or when the fine patterns are so dense that the auxiliary patterns cannot be attached, no auxiliary patterns are provided.
【００９４】また、補助パターンの位相（そこを通過す
る露光光の位相）を対象とするものの位相（そこを通過
する露光光の位相）に対して反転させてリム型の位相シ
フトマスクとしてもいい。この時、対象としている微細
パターンが光透過部でその回りが遮光部の場合には微細
パターンに対して補助パターンの位相を反転させ、対象
としている微細パターンが遮光部でその回りが光透過部
の場合には回りの部分に対して補助パターンの位相を反
転させる。A rim type phase shift mask may be obtained by inverting the phase of the auxiliary pattern (the phase of the exposure light passing therethrough) with respect to the phase of the auxiliary pattern (the phase of the exposure light passing therethrough). . At this time, if the target fine pattern is a light transmitting part and the surrounding area is a light shielding part, the phase of the auxiliary pattern is inverted with respect to the fine pattern, and the target fine pattern is the light shielding part and the surrounding area is a light transmitting part. In the case of, the phase of the auxiliary pattern is inverted with respect to the surrounding part.
【００９５】図１６−１は前述の実施形態でも採り上げ
たゲートパターンの微細な2本の幅wの線に補助パターン
を付設した例であり、図１６−１の例は一対のゲートパ
ターンを間隔sをあけて幅w'の補助パターンで取り囲ん
だものである。図１６−２はゲートパターンの微細な線
に光透過部に対して位相を反転させた斜線で示す幅w'の
リム型の補助パターンを付設した例を示す。FIG. 16A is an example in which an auxiliary pattern is provided on two fine lines of the width w of the gate pattern also adopted in the above-described embodiment. In the example of FIG. It is surrounded by an auxiliary pattern of width w 'with an interval of s. FIG. 16B shows an example in which fine lines of the gate pattern are provided with rim-shaped auxiliary patterns having a width w ′ indicated by oblique lines and having a phase inverted with respect to the light transmitting portion.
【００９６】本実施形態の露光方法による二重露光の結
果を図２０に示す。FIG. 20 shows the result of double exposure by the exposure method of this embodiment.
【００９７】ここのでの二重露光は像側開口数ＮＡが
０．６の投影光学系と波長λが２４８ｎｍの露光光を用
いた。図２０は図１６−１のようにw＝０．１２μｍの
微細線を有するゲートパターンの回りにw'＝s＝０．０
３μｍの補助パターンを付設したマスクを用いた。The double exposure here used a projection optical system having an image-side numerical aperture NA of 0.6 and exposure light having a wavelength λ of 248 nm. FIG. 20 shows that w ′ = s = 0.0 around a gate pattern having a fine line of w = 0.12 μm as shown in FIG.
A mask provided with an auxiliary pattern of 3 μm was used.
【００９８】図２０の上段は図１７の有効光源を形成す
る照明光でファイン露光を行なった結果を、図２０の中
段は図１９の有効光源を形成する照明光でラフ露光を行
なった結果を、図２０の下段はこのファイン露光とラフ
露光の二重露光を行なった結果を示す。The upper part of FIG. 20 shows the result of fine exposure using the illumination light forming the effective light source of FIG. 17, and the middle part of FIG. 20 shows the result of rough exposure using the illumination light forming the effective light source of FIG. The lower part of FIG. 20 shows the result of performing the double exposure of the fine exposure and the rough exposure.
【００９９】図２０が示す通り、ラフ露光の場合は２つ
の微細な線が解像されないでボケて露光させるのに対
し、ファイン露光の場合には２つの微細な線が解像され
ているが、２つの線の間隔が開きすぎていてゲートパタ
ーンとして必要な形状が得られていないが、二重露光の
場合は2つの微細な線が解像され且つゲートパターンと
して必要な形状が得られている。As shown in FIG. 20, in the case of rough exposure, two fine lines are exposed without blurring, whereas in the case of fine exposure, two fine lines are resolved. 2. The interval between the two lines is too wide to obtain the required shape as a gate pattern, but in the case of double exposure, two fine lines are resolved and the required shape as a gate pattern is obtained. I have.
【０１００】このように本実施形態においても、通常の
投影露光装置と一枚のマスク或いはそれぞれに若干の改
良を施しただけで、装置の限界解像以下の線幅のパター
ンを有する回路パターンを二重露光によってウエハに露
光できるので、装置間のウエハの移動、マスクの交換等
が不要であり、二重露光に要する時間を短くできる。As described above, also in this embodiment, a circuit pattern having a line width equal to or less than the limit resolution of the apparatus can be obtained by slightly improving the ordinary projection exposure apparatus and one mask or each of them. Since the wafer can be exposed by the double exposure, it is not necessary to move the wafer between the apparatuses, exchange the mask, and the like, and the time required for the double exposure can be shortened.
【０１０１】以上説明した各実施形態において、ウエハ
２１の多数個のショット領域にラフ露光とファイン露光
の二重露光を行なう場合、各ショット毎に二つの露光を
行なう形態、一方の露光を１枚又は１ロットの複数枚の
ウエハの全てショットに対して行なった後で、現像する
ことなく、他方の露光をこの１枚又は複数枚のウエハの
全てショットに対して行なう形態が採れる。In each of the embodiments described above, when performing double exposure of rough exposure and fine exposure on a large number of shot areas of the wafer 21, two exposures are performed for each shot, and one exposure is performed for one shot. Alternatively, after all the shots of a plurality of wafers in one lot are performed, the other exposure is performed on all the shots of the one or more wafers without developing.
【０１０２】更に、二つの露光の照明光を互いに偏光方
向が直交する直線偏光光として、二つの露光に使用する
光が干渉しないようにして、二つ露光を同時に行なうこ
とも可能である。Further, it is also possible to perform two exposures at the same time by using the illumination light of the two exposures as linearly polarized light whose polarization directions are orthogonal to each other so that the light used for the two exposures does not interfere.
【０１０３】また、本発明は、ネガレジスト及びポジレ
ジストのどちらにも対処できる。Further, the present invention can deal with both negative resists and positive resists.
【０１０４】[0104]
【発明の効果】以上説明したように本発明によれば、短
い時間で、二重露光や三重露光などの多重露光が行なえ
る露光方法や露光装置を提供でき、従って、微細パター
ンを有するデバイスを早く製造できるデバイス製造方法
を提供できる。As described above, according to the present invention, it is possible to provide an exposure method and an exposure apparatus capable of performing multiple exposures such as double exposure and triple exposure in a short time. Therefore, a device having a fine pattern can be provided. A device manufacturing method that can be manufactured quickly can be provided.
【図１】本発明の露光装置の一例を示す図である。FIG. 1 is a view showing one example of an exposure apparatus of the present invention.
【図２】本発明の露光方法のフローの一例を示す図であ
る。FIG. 2 is a diagram showing an example of a flow of an exposure method of the present invention.
【図３】ゲートチャート形状を示す摸式図である。FIG. 3 is a schematic diagram showing a gate chart shape.
【図４】本発明の露光方法の実施形態1の露光条件と像
強度を示す摸式図である。FIG. 4 is a schematic diagram showing exposure conditions and image intensity according to the first embodiment of the exposure method of the present invention.
【図５】実施形態1の微細な線の部分の強度分布と露光
裕度を示す模式図である。FIG. 5 is a schematic diagram showing an intensity distribution and an exposure latitude of a fine line portion according to the first embodiment.
【図６】照明光学系の開口絞り交換手段の一例を示す模
式図である。FIG. 6 is a schematic diagram showing an example of an aperture stop replacing unit of the illumination optical system.
【図７】照明光学系の開口絞り交換手段の他の例を示す
模式図である。FIG. 7 is a schematic diagram showing another example of an aperture stop replacing unit of the illumination optical system.
【図８】投影光学系の開口絞り交換手段の一例を示す模
式図である。FIG. 8 is a schematic diagram showing an example of an aperture stop changing unit of the projection optical system.
【図９】投影光学系の開口絞り交換手段の他の例を示す
模式図である。FIG. 9 is a schematic diagram showing another example of the aperture stop replacing means of the projection optical system.
【図１０】投影光学系の開口絞りの回転手段の一例を示
す模式図である。FIG. 10 is a schematic diagram showing an example of a rotation unit of an aperture stop of the projection optical system.
【図１１】集積化されたゲートチャートの一例を示す摸
式図である。FIG. 11 is a schematic diagram showing an example of an integrated gate chart.
【図１２】本発明の露光方法の実施形態２の露光条件と
像強度を示す模式図である。FIG. 12 is a schematic diagram showing exposure conditions and image intensity according to a second embodiment of the exposure method of the present invention.
【図１３】ファイン露光の他の実施例を示す模式図であ
る。FIG. 13 is a schematic view showing another embodiment of fine exposure.
【図１４】斜入射照明の効果を示す説明図である。FIG. 14 is an explanatory diagram showing an effect of oblique illumination.
【図１５】通 常の投影露光装置を示す概略図である。FIG. 15 is a schematic view showing a normal projection exposure apparatus.
【図１６】本発明の露光方法に関連する実施形態で用い
る補助パターン付ゲートパターンの一例を示す説明図で
ある。FIG. 16 is an explanatory diagram showing an example of a gate pattern with an auxiliary pattern used in an embodiment related to the exposure method of the present invention.
【図１７】本発明の露光方法に関連する実施形態で用い
る補助パターン付ゲートパターンの他の例を示す説明図
である。FIG. 17 is an explanatory diagram showing another example of a gate pattern with an auxiliary pattern used in an embodiment related to the exposure method of the present invention.
【図１８】有効光源の一例を示す図である。FIG. 18 is a diagram illustrating an example of an effective light source.
【図１９】有効光源の他の例を示す図である。FIG. 19 is a diagram showing another example of the effective light source.
【図２０】有効光源の他の例を示す図である。FIG. 20 is a diagram showing another example of the effective light source.
【図２１】実施形態３の二重露光の効果を示す説明図で
ある。FIG. 21 is an explanatory diagram illustrating the effect of double exposure according to the third embodiment.
１１ 露光光源 １２ 照明光学系 １３ 照明モ−ド １４ マスク １５ 照明光学系の開口絞り交換手段 １６ 照明光学系の開口絞り １７ マスクステ−ジ １８ 投影光学系 １９ 投影光学系の開口絞り ２０ 投影光学系の開口絞り交換手段 ２１ ウエハ ２２ ウエハステ−ジ DESCRIPTION OF SYMBOLS 11 Exposure light source 12 Illumination optical system 13 Illumination mode 14 Mask 15 Illumination optical system aperture stop exchange means 16 Illumination optical system aperture stop 17 Mask stage 18 Projection optical system 19 Projection optical system aperture stop 20 Projection optical system Aperture stop exchange means 21 Wafer 22 Wafer stage
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｌ 21/30 ５６９Ｚ ５７４ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 569Z 574
Claims (25)
影光学系の空間周波数通過スペクトルとを変えて照明し
て共通の被露光領域に投影することを特徴とする露光方
法。1. An exposure method, wherein the same mask pattern is illuminated under different illumination conditions and a spatial frequency pass spectrum of a projection optical system and projected onto a common exposure area.
間周波数通過スペクトルを変えた形で小σ（シグマ）と
大σとで照明して共通の被露光領域に投影することを特
徴とする露光方法。2. An exposure method wherein the same mask pattern is illuminated with a small σ (sigma) and a large σ while changing the spatial frequency transmission spectrum of a projection optical system and projected onto a common exposure area. Method.
間周波数通過スペクトルを変えた形で小NA（開口数）と
大NAとで照明して共通の被露光領域に投影することを特
徴とする露光方法。3. The method according to claim 1, wherein the same mask pattern is illuminated with a small NA (numerical aperture) and a large NA while changing the spatial frequency pass spectrum of the projection optical system and projected onto a common exposure area. Exposure method.
間周波数通過スペクトルを変えた形で斜め照明と垂直照
明を行なって共通の被露光領域に投影することを特徴と
する露光方法。4. An exposure method, wherein oblique illumination and vertical illumination are performed on the same mask pattern while changing the spatial frequency transmission spectrum of a projection optical system, and the projection is performed on a common exposure area.
置の解像限界以下の線幅を持つ開口パターンを有するこ
とを特徴とする請求項１乃至請求項４のいずれか一つに
記載の露光方法。5. The exposure method according to claim 1, wherein the mask pattern has an opening pattern having a line width smaller than a resolution limit of an exposure apparatus to be used. .
とを特徴とする請求項５に記載の露光方法。6. The exposure method according to claim 5, wherein a plurality of the opening patterns are arranged.
有することを特徴とする請求項５に記載の露光方法。7. The exposure method according to claim 5, wherein the mask pattern has a phase shift pattern.
トルを変えるために前記投影光学系の開口絞りの開口形
状及び／又は透過率分布を変えることを特徴とする請求
項１−４のいずれかに記載の露光方法。8. The projection optical system according to claim 1, wherein an aperture shape and / or transmittance distribution of an aperture stop of the projection optical system is changed to change a spatial frequency transmission spectrum of the projection optical system. Exposure method according to the above.
ー又はF2エキシマレーザーから光で前記マスクパターン
を照明することを特徴とする請求項１−８のいずれかに
記載の露光方法。9. The exposure method according to claim 1, wherein the mask pattern is illuminated with light from a KrF excimer laser, an ArF excimer laser, or an F2 excimer laser.
いずれかより成る投影光学系によって前記マスクパター
ンを投影することを特徴とする請求項１−８のいずれか
に記載の露光方法。10. The exposure method according to claim 1, wherein the mask pattern is projected by a projection optical system including any one of a refraction system, a reflection-refraction system, and a reflection system.
なく各照明条件で順次露光することを特徴とする請求項
１−１０に記載の露光方法。11. The exposure method according to claim 1, wherein the exposed area is sequentially exposed under each illumination condition without being developed in the middle.
照明条件における光が互いに干渉しない状態で同時に露
光することを特徴とする請求項１−１０に記載の露光方
法。12. The exposure method according to claim 1, wherein the area to be exposed is exposed simultaneously under the respective illumination conditions without light under the respective illumination conditions interfering with each other.
空間周波数通過スペクトルを変えた形で照明条件を変え
て照明して共通の被露光領域に投影する露光モードを有
することを特徴とする露光装置。13. An exposure apparatus having an exposure mode in which the same mask pattern is illuminated under different illumination conditions while changing the spatial frequency transmission spectrum of a projection optical system, and projected onto a common exposure area. .
空間周波数通過スペクトルを変えた形で小σ（シグマ）
と大σとで照明して共通の被露光領域に投影する露光モ
ードを有することを特徴とする露光装置。14. The same mask pattern is formed by changing the spatial frequency pass spectrum of the projection optical system to a small σ (sigma).
An exposure apparatus having an exposure mode in which light is projected at a common exposure area by illuminating with a large σ.
空間周波数通過スペクトルを変えた形で小NA（開口数）
と大NAとで照明して共通の被露光領域に投影する露光モ
ードを有することを特徴とする露光装置。15. A small NA (numerical aperture) of the same mask pattern in a form in which a spatial frequency pass spectrum of a projection optical system is changed.
An exposure apparatus having an exposure mode for illuminating with a large NA and projecting onto a common exposure area.
空間周波数通過スペクトルを変えた形で斜め照明と垂直
照明を行なって共通の被露光領域に投影する露光モード
を有することを特徴とする露光装置。16. An exposure apparatus having an exposure mode in which oblique illumination and vertical illumination are performed on the same mask pattern while changing the spatial frequency pass spectrum of a projection optical system, and the same mask pattern is projected onto a common exposure area. .
装置の解像限界以下の線幅を持つ開口パターンを有する
ことを特徴とする請求項１４乃至請求項１６のいずれか
一つに記載の露光装置。17. The exposure apparatus according to claim 14, wherein the mask pattern has an opening pattern having a line width smaller than a resolution limit of an exposure apparatus to be used. .
ことを特徴とする請求項１７に記載の露光方法。18. The exposure method according to claim 17, wherein a plurality of the opening patterns are arranged.
を有することを特徴とする請求項１７に記載の露光装
置。19. The exposure apparatus according to claim 17, wherein the mask pattern has a phase shift pattern.
クトルを変えるために前記投影光学系の開口絞りの開口
形状及び／又は透過率分布を変えることを特徴とする請
求項１２−１６のいずれかに記載の露光装置。20. The method according to claim 12, wherein an aperture shape and / or transmittance distribution of an aperture stop of the projection optical system is changed to change a spatial frequency pass spectrum of the projection optical system. Exposure apparatus according to the above.
ザー又はF2エキシマレーザーから光で前記マスクパター
ンを照明することを特徴とする請求項１３−２０のいず
れかに記載の露光装置。21. The exposure apparatus according to claim 13, wherein the mask pattern is illuminated with light from a KrF excimer laser, an ArF excimer laser, or an F2 excimer laser.
いずれかより成る投影光学系によって前記マスクパター
ンを投影することを特徴とする請求項１３−２０いずれ
かに記載の露光装置。22. The exposure apparatus according to claim 13, wherein the mask pattern is projected by a projection optical system including any one of a refraction system, a reflection-refraction system, and a reflection system.
なく各照明条件で順次露光することを特徴とする請求項
１２−２２に記載の露光装置。23. The exposure apparatus according to claim 12, wherein the exposure area is sequentially exposed under each illumination condition without being developed on the way.
照明条件における光が互いに干渉しない状態で同時に露
光することを特徴とする請求項１３−２２に記載の露光
装置。24. The exposure apparatus according to claim 13, wherein the exposed area is simultaneously exposed under the respective illumination conditions without light under the respective illumination conditions interfering with each other.
光装置を用いてデバイスパターンでウエハを露光する段
階と、露光したウエハを現像する段階とを有することを
特徴とするデバイス製造方法。25. A device manufacturing method, comprising: exposing a wafer with a device pattern using the exposure apparatus according to claim 13; and developing the exposed wafer.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18423998A JP3647271B2 (en) | 1998-06-30 | 1998-06-30 | Exposure method and exposure apparatus |
| US09/337,040 US6930754B1 (en) | 1998-06-30 | 1999-06-28 | Multiple exposure method |
| EP99305098A EP0969327B1 (en) | 1998-06-30 | 1999-06-29 | Multiple exposure apparatus and method |
| DE69936687T DE69936687T2 (en) | 1998-06-30 | 1999-06-29 | Apparatus and method for multiple exposure |
| US11/003,889 US7023522B2 (en) | 1998-06-30 | 2004-12-06 | Multiple exposure method |
| US11/230,676 US7505112B2 (en) | 1998-06-30 | 2005-09-21 | Multiple exposure method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18423998A JP3647271B2 (en) | 1998-06-30 | 1998-06-30 | Exposure method and exposure apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000021721A true JP2000021721A (en) | 2000-01-21 |
| JP3647271B2 JP3647271B2 (en) | 2005-05-11 |
Family
ID=16149827
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18423998A Expired - Fee Related JP3647271B2 (en) | 1998-06-30 | 1998-06-30 | Exposure method and exposure apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3647271B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007533128A (en) * | 2004-04-09 | 2007-11-15 | カール ツァイス エスエムテー アクチェンゲゼルシャフト | Substrate patterning method using multiple exposure |
| US7523438B2 (en) | 2001-08-21 | 2009-04-21 | Asml Masktools B.V. | Method for improved lithographic patterning utilizing optimized illumination conditions and high transmission attenuated PSM |
| JP2013006238A (en) * | 2011-06-24 | 2013-01-10 | Seiko Epson Corp | Horizontal articulated robot |
-
1998
- 1998-06-30 JP JP18423998A patent/JP3647271B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7523438B2 (en) | 2001-08-21 | 2009-04-21 | Asml Masktools B.V. | Method for improved lithographic patterning utilizing optimized illumination conditions and high transmission attenuated PSM |
| JP2007533128A (en) * | 2004-04-09 | 2007-11-15 | カール ツァイス エスエムテー アクチェンゲゼルシャフト | Substrate patterning method using multiple exposure |
| JP2013006238A (en) * | 2011-06-24 | 2013-01-10 | Seiko Epson Corp | Horizontal articulated robot |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3647271B2 (en) | 2005-05-11 |
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