561280 A7 _____B7__ 五、發明說明（丨） (發明之詳細說明） (發明所屬之技術領域） (請先閱讀背面之注意事項再填寫本頁) 本發明係一種於X射線顯微鏡' X射線分析裝置、X 射線曝光裝置等X射線光學系統內所使用的多層膜反射鏡 。特別是關於一種使用該多層膜反射鏡的X射線曝光裝置 【習知技術】 近年來，隨著半導體積體電路的微細化發展，爲提昇 受限於光的繞射極限的光學系統之解析度，採用較以往的 紫外線波長更短（11〜14nm)的X射線來運用在投影微影製 程上之技術乃漸被開發（例如，可參照D.Tichenor，et al.， SPIE 2437(1995) 292 )。此種技術近來被稱爲 EUV(Extreme Ultraviolet)微影，可望能達到以往I90nm波 長的光線在施以光微影時所無法取得之70nm以下的解析 度。 在X射線的波長區域內之物質的複折射率n ’係以 n=l-5 -ik(5、K :複數)所表示。此折射率的虛數k係表示 -X射線的吸收。因5、k相較於1係極小數値’故在此區 域內之折射率極近於1。致無法使用以往之透鏡等光學元 件，而需使用反射光學系統。以利用斜向入射於反射面= X射線的全反射來進行反射之斜向入射光學系統而言’胃 入射角度較全反射臨界角0 c (波長10nm時爲20°以下） 爲小（接近垂直）時，其反射率將非常小。又’此處所^旨 4 _ 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 561280 A7 _____Β7_____ 五、發明說明（^ ) 之入射角度，係表示入射面的法線與入射光的光軸所成的 角度。 是以，乃使用一種多層膜反射鏡，其是積層了界面之 振幅反射率儘可能高的物質來設置多數的反射面（例如數 十〜數百層），根據光干涉理論，調整各層厚度俾使各自 的反射波之相位重合。多層膜反射鏡，係將所使用之X射 線波長區域的折射率與真空的折射率(=1)之差値大之物質 與差値小之物質，於基板上交互積層而形成。而多層膜的 材料，係以習知的鎢/碳、鉬/碳等之組合者；且藉由濺 鍍或真空蒸鍍、CVD等薄膜形成技術來成膜。 再者，多層膜反射鏡，因爲亦可反射垂直入射的X射 線，故所構成的光學系統之像差較採全反射的斜向入射光 學系統更小。 又，多層膜反射鏡爲使反射波的相位重合而滿足布拉 格式2dsin0=nA (d表多層膜的週期長，Θ表斜向入射 角度，7Γ /2表入射角度，λ表X射線的波長）之際，因具 有使X射線相當程度反射的波長依存性，所以必須慎選滿 足於該式子之各因子。 以鉬（Mo)/矽（Si)作爲多層膜時，如所周知者，波長 12.6nm的矽之L吸收端的長波長側具有高反射率。是以， 在波長13nm附近，較易製得在直向入射（入射角度爲〇。 )時可達60%以上之高反射率的多層膜反射鏡。此種採 / Si多層膜之反射鏡’被稱爲£uVL(Extreme Ultraviolet Lithography)，亦能應用於使用軟X射線之縮 5 P氏張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐)一 —- •---------------- (請先閱讀背面之注意事項再填寫本頁) 今0· .線 561280 A7 __B7 _ 五、發明說明（4 ) 小投影微影技術。 【發明所欲解決之課題】 (請先閱讀背面之注意事項再填寫本頁) 採Mo/Si的多層膜反射鏡，雖具有上述般之高反射 率，然而，如同布拉格式所示般，除波長依存性外亦具有 入射角度依存性。用於微影之照明光學系統或投影光學系 統的反射鏡，其基板上各點的光線之入射角度各異’入射 角度之差値範圍從數度至十餘度。因而’倘在基板的全面 上形成等厚之多層膜，則將因爲入射角度之差，以致在基 板表面上產生反射率之差異。 圖6所示者，係表示反射率對應於反射角度的關係圖 。該圖係以理論方式表示週期長69A，積層數50層對、入 射光波長13.36nm時之入射角度與反射率之圖。橫軸爲入 射角度，縱軸爲反射率，實線表s偏光，虛線表無偏光。 又，在該圖之中的層對組合，在Mo/Si多層膜時，係以 相鄰的Mo層一層與Si層一層之組合爲一對，週期長則表 1層對之厚度。Mo層一層的厚度對週期長的比値以Γ表示 ，在此多層膜中，Γ爲0.35且爲定値。 如圖6所示般，反射率隨入射角度而改變，入射角度 爲〇°時的反射率雖達約74%，然而，入射角度爲1〇。時 的反射率爲60%以上，反射率之降幅達10%以上。 針對此點，習知的作法，乃是調整多層膜的膜厚分布 ，俾使特定波長的光在表面上各點的入射角度皆具高反射 率。 圖7所示者，係表入射光的波長爲13.36nm時，反射 6 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） '' 561280 A7 ____B7__ 五、發明說明（W ) 率相對於入射角度達最高値之週期長及膜厚（週期長X層 對數）的關係圖。橫軸爲入射角度，左側之縱軸爲週期長 ，右側的縱軸爲膜厚。Γ爲0.35。 由圖7可得知’當入射角度爲〇。時其反射率達最高 値的週期長約68.26A，膜厚約3413A ;當入射角度爲10。 時其反射率達最高値的週期長約69.31人，膜厚約3466人。 是以，各入射角度之中，欲使反射率達最高値時，倘其入 射角度爲10°之點時，須使週期長較入射角度爲0°之點 多1A左右。Mo/Si多層膜一般爲50層對，隨著週期長 的加大將致使多層膜的膜厚差達4.7nm。從而，經過精密 加工之光學系統（基板）的表面形狀具有該程度的變化量 。此程度之變化量，已經高於波面像差所能容許的數値， 故成爲光學特性劣化的要因。 本發明係鑑於上述之問題點，其目的乃在於提供一種 光學特性不會劣化，且不依存於入射角度之具高反射率的 多層膜反射鏡，以及，使用該多層膜反射鏡的X射線曝光 裝置。 【用以解決課題之手段】 爲解決上述課題，本發明之多層膜反射鏡，係讓在軟 X射線區域之折射率與真空折射率的差距大的物質所構成 之第1層、折射率與真空折射率的差距小的物質所構成之 第2層於基板上交互積層所得者；其特徵在於，第1層厚 度相對於第1層厚度與第2層厚度的合計厚度之比在反射 鏡面內具有分布。 7 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） ----------------- (請先閱讀背面之注意事項再填寫本頁) 訂- .線 561280 A7 __B7 _ 五、發明說明（ί ) 於本發明中，該分布，在該反射鏡面內之X射線的入 射角度大處係降低該比値乃爲所希望者。 藉由使得第1層厚度相對於第1層厚度與第2層厚度 之合計厚度之比（Γ )在反射鏡面內對應於入射角度分布而 分布，則可在反射鏡面內之各點的入射角度獲取最大的反 射率。此時因無須改變週期長，故反射鏡的光學性能不致 劣化。 於本發明中，當該分布係在該反射鏡面內之X射線的 入射角度大之處，降低該比乃爲所希望者。 一般而言，外周側的入射角度較基板的中心側要大。 因之，如圖9所示般，在入射角度較大的外周側，藉著降 低第1層厚度相對於第1層厚度與第2層厚度之合計的比（ Γ )，可在外周側獲得高反射率。 在本發明中，上述第1層，較佳爲鋁(Mo)所構成之單 層或以鉬、釕(Ru)、鉬之順序所積層之複數層。又，上述 第2層，較佳爲矽（Si)所構成之層。藉此，可獲致廉價、 持久性佳、反射波面的相位一致之多層膜反射鏡。 本發明之曝光裝置係具有：X射線光源，用來產生X 射線；照明光學系統，用來將X射線從X·射線光源引導至 光罩；以及，投影光學系統，用來將X射線從上述光罩引 導至感光性基板；以將上述光罩的圖案轉印至感光性基板 ;其特徵在於，該照明光學系統、該光罩以及該投影光學 系統當中之至少一者具備多層膜反射鏡；該多層膜反射鏡 ’係讓在軟X射線區域之折射率與真空折射率的差距大的 8 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁)561280 A7 _____B7__ V. Description of the invention (丨) (Detailed description of the invention) (Technical field to which the invention belongs) (Please read the precautions on the back before filling out this page) The present invention is an X-ray microscope, X-ray analysis device, Multilayer film reflectors used in X-ray optical systems such as X-ray exposure devices. In particular, an X-ray exposure apparatus using the multilayer film mirror [known technique] In recent years, with the development of miniaturization of semiconductor integrated circuits, in order to improve the resolution of optical systems that are limited by the diffraction limit of light The use of X-rays with shorter ultraviolet wavelengths (11 to 14 nm) than conventional UV ray lithography processes has been gradually developed (for example, see D. Tichenor, et al., SPIE 2437 (1995) 292 ). This technology has recently been called EUV (Extreme Ultraviolet) lithography, and it is expected to reach a resolution below 70 nm that was previously unavailable when light lithography was applied to light with a wavelength of I90 nm. The complex refractive index n 'of a substance in the wavelength region of X-rays is represented by n = l-5 -ik (5, K: complex number). The imaginary number k of this refractive index represents -X-ray absorption. Because 5, k is extremely small compared to 1, the refractive index in this region is very close to 1. As a result, conventional optical elements such as lenses cannot be used, and a reflective optical system is required. In the case of an oblique incidence optical system that uses oblique incidence on the reflecting surface = total reflection of X-rays, the 'stomach incidence angle is smaller than the critical angle of total reflection 0 c (at a wavelength of 10 nm or less) which is small (close to vertical) ), The reflectivity will be very small. Also 'here ^ Mission 4 _ The size of the paper is applicable to the Chinese National Standard (CNS) A4 (210 X 297 mm) 561280 A7 _____ Β7 _____ 5. The angle of incidence of the invention description (^) indicates the normal and incidence of the incident surface The angle formed by the optical axis of light. Therefore, a multilayer film reflector is used, which is a layered material that has as high an amplitude reflectance as possible at the interface to set most reflecting surfaces (for example, tens to hundreds of layers). The thickness of each layer is adjusted according to the light interference theory The phases of the respective reflected waves are made coincident. Multilayer film mirrors are formed by laminating a substance with a large difference between the refractive index of the X-ray wavelength region and the refractive index of the vacuum (= 1) and a substance with a small difference on the substrate. The material of the multilayer film is a conventional combination of tungsten / carbon, molybdenum / carbon, and the like; and the film is formed by thin film formation techniques such as sputtering, vacuum evaporation, and CVD. Furthermore, the multilayer film reflector can also reflect X-rays that are incident on vertically, so the aberration of the optical system is smaller than that of an oblique incident optical system that adopts total reflection. In addition, the multilayer film mirror satisfies the Bragg-type 2dsin0 = nA in order to make the phases of the reflected waves coincide (d represents the long period of the multilayer film, Θ represents the oblique incidence angle, 7Γ / 2 represents the incident angle, and λ represents the wavelength of X-rays) In this case, since there is a wavelength dependency that reflects X-rays to a considerable degree, it is necessary to carefully select each factor satisfying the formula. When molybdenum (Mo) / silicon (Si) is used as the multilayer film, as is well known, the long wavelength side of the L absorption end of silicon having a wavelength of 12.6 nm has high reflectance. Therefore, at a wavelength of about 13 nm, it is relatively easy to produce a multilayer film reflector with a high reflectance of 60% or more under direct incidence (incidence angle 0 °). This type of mirror with / Si multilayer film is called £ uVL (Extreme Ultraviolet Lithography), and it can also be applied to the use of soft X-rays with a 5 P-scale scale applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 Mm) I —- • ---------------- (Please read the notes on the back before filling this page) Today 0 ·. Line 561280 A7 __B7 _ 5. Description of the invention ( 4) Small projection lithography technology. [Questions to be Solved by the Invention] (Please read the precautions on the back before filling out this page) Mo / Si multilayer film mirrors have the high reflectance as described above, but, as shown by the Bragg formula, In addition to wavelength dependence, it also has incident angle dependence. Reflectors for illumination optical systems or projection optical systems for lithography have different incidence angles of light rays at various points on the substrate. The difference in incidence angle ranges from a few degrees to more than ten degrees. Therefore, 'if a multilayer film of the same thickness is formed on the entire surface of the substrate, a difference in reflectance will occur on the surface of the substrate due to the difference in the angle of incidence. The one shown in FIG. 6 is a graph showing the relationship between the reflectance and the reflection angle. This diagram is a theoretical representation of the incident angle and reflectance at a period of 69A, a number of layers of 50 layers, and an incident light wavelength of 13.36nm. The horizontal axis is the incident angle, and the vertical axis is the reflectivity. The solid line indicates s polarization, and the dotted line indicates no polarization. In the figure, the layer-to-layer combination is a combination of a layer of adjacent Mo layers and a layer of Si layers in a Mo / Si multilayer film, and the thickness of each layer in Table 1 is as long as the period is long. The ratio 的 of the thickness of the Mo layer to the period length is represented by Γ. In this multilayer film, Γ is 0.35 and is constant. As shown in FIG. 6, the reflectance changes with the incident angle. Although the reflectance at an incident angle of 0 ° is about 74%, the incident angle is 10. The reflectance at this time is more than 60%, and the decrease in reflectivity is more than 10%. In view of this, a conventional method is to adjust the film thickness distribution of the multilayer film so that the incident angle of light of a specific wavelength at each point on the surface has a high reflectivity. As shown in Figure 7, when the wavelength of the incident light is 13.36nm, the size of the reflected paper is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) '' 561280 A7 ____B7__ V. Description of the invention (W) The relationship between the period length and the film thickness (period length X layer logarithm) relative to the incident angle with the highest angle of incidence. The horizontal axis is the angle of incidence, the vertical axis on the left is the cycle length, and the vertical axis on the right is the film thickness. Γ is 0.35. It can be seen from Fig. 7 'that the incident angle is zero. When its reflectivity reaches the highest, the period of 値 is about 68.26A and the film thickness is about 3413A; when the incident angle is 10. When its reflectivity reaches the highest value, the period is about 69.31 people and the film thickness is about 3466 people. Therefore, if the reflectivity is to be the highest among the incident angles, if the incident angle is 10 °, the period must be longer than the incident angle of 0 ° by about 1A. Mo / Si multilayer films are generally 50 pairs. As the cycle length increases, the thickness difference of the multilayer films can reach 4.7nm. Therefore, the surface shape of the precision-processed optical system (substrate) has a change amount of this degree. The amount of change at this level is already higher than the allowable number of wavefront aberrations, and therefore it is a cause of deterioration of optical characteristics. The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a multilayer film reflector with high reflectivity that does not deteriorate in optical characteristics and does not depend on an incident angle, and an X-ray exposure using the multilayer film reflector. Device. [Means to solve the problem] In order to solve the above problems, the multilayer film mirror of the present invention is a first layer composed of a substance having a large difference between a refractive index and a vacuum refractive index in a soft X-ray region, a refractive index and The second layer composed of a substance with a small difference in vacuum refractive index is obtained by alternately stacking the substrate on the substrate; it is characterized in that the ratio of the thickness of the first layer to the total thickness of the first layer and the second layer is within the reflection mirror surface With distribution. 7 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) ----------------- (Please read the precautions on the back before filling this page) Order-.line 561280 A7 __B7 _ 5. Description of the invention (ί) In the present invention, the distribution, the angle of incidence of X-rays in the mirror surface is reduced by a large ratio, which is desirable. By making the ratio of the thickness of the first layer to the total thickness of the first layer and the thickness of the second layer (Γ) distributed in the reflecting mirror surface corresponding to the incidence angle distribution, the incident angle at each point in the reflecting mirror surface can be distributed. Get maximum reflectivity. At this time, since the period need not be changed, the optical performance of the mirror is not deteriorated. In the present invention, when the distribution angle of the X-rays in the mirror surface is large, it is desirable to reduce the ratio. Generally, the incident angle on the outer peripheral side is larger than the center side of the substrate. Therefore, as shown in FIG. 9, on the outer peripheral side with a larger incident angle, the ratio of the thickness of the first layer to the total thickness of the first layer and the thickness of the second layer (Γ) can be reduced on the outer peripheral side. High reflectivity. In the present invention, the first layer is preferably a single layer composed of aluminum (Mo) or a plurality of layers laminated in the order of molybdenum, ruthenium (Ru), and molybdenum. The second layer is preferably a layer made of silicon (Si). This makes it possible to obtain a multi-layered mirror with low cost, excellent durability, and a uniform phase of the reflection wave surface. The exposure device of the present invention includes: an X-ray light source for generating X-rays; an illumination optical system for directing X-rays from the X-ray light source to a photomask; and a projection optical system for directing X-rays from the above The photomask is guided to the photosensitive substrate; the pattern of the photomask is transferred to the photoconductive substrate; characterized in that at least one of the illumination optical system, the photomask and the projection optical system is provided with a multilayer film reflector; This multilayer film mirror is a 8-sheet paper with a large gap between the refractive index in the soft X-ray area and the vacuum refractive index. It is applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the (Please fill in this page again)
561280 A7 _______B7__ 五、發明說明（b ) 物質所構成之第1層、折射率與真空折射率的差距小的物 質所構成之第2層於基板上交互積層所得者，第1層厚度 相對於第1層厚度與第2層厚度的合計厚度之比在反射鏡 面內具有分布。 在反射鏡面內，可在不致改變多層膜的週期長之前提 下來獲致最大的反射率，因此，防止了進行週期長分布修 正時所產生之膜厚分布導致光學特性劣化，可提供一種高 性能的X射線曝光裝置。 【發明之實施形態】 多層膜反射鏡，乃是運用上述之布拉格式子，一旦使 週期長變化，則反射率達最高値的波長亦隨而改變。另一 方面，因爲構成多層膜的物質之折射率互異，即使週期長 保持不變而改變Γ，其反射率達最高値的波長仍將改變。 圖8所不者，係爲入射波長與反射率的關係圖。於該 圖中係顯示了週期長爲69A的Mo/Si多層膜，在入射角 度爲0°時其對於入射光線之波長的反射率。橫軸爲波長 ，縱軸爲反射率。再者，圖中的各線係表示Γ由0.3起至 0.5之間以0.05刻度進行改變者。 由此圖可得知，藉著固定週期長且使Γ改變，則反射 率達最高値的波長亦生變化。亦即，Γ爲0.5時，波長在 13.4nm附近之反射率最筒値爲約72%，Γ爲0.3時，波長 在13.6附近的反射率最高値爲約72%。因此，即使固定多 層膜的週期長而改變Γ値，仍使得固定入射角度所對應的 反射率達到最高値時的波長產生改變，致與改變週期長之 9 幸、紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 裝561280 A7 _______B7__ 5. Description of the invention (b) The first layer made of a substance, and the second layer made of a substance with a small difference between the refractive index and the vacuum refractive index are obtained by alternately stacking the substrate, and the thickness of the first layer is The ratio of the thickness of the first layer to the total thickness of the second layer has a distribution in the mirror surface. In the mirror surface, the maximum reflectance can be obtained before the period of the multilayer film is not changed. Therefore, the deterioration of optical characteristics caused by the film thickness distribution generated when the period length distribution correction is performed can be provided, and a high-performance X-ray exposure device. [Embodiment of the invention] The multilayer film reflector uses the above-mentioned Bragg formula, and once the period is changed, the wavelength at which the reflectance reaches the highest value also changes. On the other hand, because the refractive indices of the materials constituting the multilayer film are different from each other, even if the period is kept constant and Γ is changed, the wavelength at which the reflectance reaches the highest value will still change. What is shown in FIG. 8 is a graph showing the relationship between the incident wavelength and the reflectance. The figure shows the Mo / Si multilayer film with a period of 69A, and its reflectance to the wavelength of incident light when the incident angle is 0 °. The horizontal axis is the wavelength and the vertical axis is the reflectivity. In addition, each line in the figure indicates that Γ is changed on a 0.05 scale from 0.3 to 0.5. It can be seen from this figure that by changing the length of the fixed period and changing Γ, the wavelength at which the reflectance reaches the highest value also changes. That is, when Γ is 0.5, the reflectance at the wavelength near 13.4 nm is about 72%, and when Γ is 0.3, the reflectance at the wavelength near 13.6 is about 72%. Therefore, even if the period of the fixed multilayer film is changed and Γ 値 is changed, the wavelength at which the reflectance corresponding to the fixed incident angle reaches the maximum value will be changed. As a result, the change period is 9 times longer. ) A4 size (210 X 297 mm) (Please read the precautions on the back before filling this page)
Lal·- 線 561280 A7 ____B7__ __ 五、發明說明（1 ) 情況成爲同樣結果。 另一方面，藉圖7可得知，當固定入射波長時，一旦 週期長改變則反射率達最高値的入射角度產生變化。是以 ，即使固定週期長而改變Γ，仍使固定的入射波長所對應 的反射率達最高値時的入射角度產生改變。只要利用此特 點，即使多層膜的週期長保持一致，可藉由選擇Γ，使反 射鏡面內之各點的入射角度得對應於固定的入射波長成爲 最大反射率的角度。 圖9所示者，係表示改變Γ値時，反射率與入射角度 的相對圖不。橫軸爲入射角度，縱軸爲反射率。此圖示中 ，係針對週期長69A、層對數50的Mo/Si多層膜入射波 長13.36mn的光之情況。圖示中的各線，表示改變Γ値後 所成立者。 由此圖可得知，藉改變Γ値可改變使反射率達最高値 的入射角度。亦即，當Γ爲0.5時反射率達最高値的入射 角度約爲4° ，然而，Γ爲0.3時約爲10° ，隨著Γ値的 漸小，則反射率達最高値的入射角度則從0°起漸增。因 而，可因應入射角度來選擇使反射率最高的Γ値，藉此獲 得商反射率。 例如，在入射角度爲0°至5°之間，Γ =0.45可得到 最高的反射率；5°至8°之間則Γ =0.4可得到最高的反射 率；8°至10°之間則Γ =0.35可得到最高的反射率。再者 ，較佳係將Γ控制在0.3至0.5的範圍內來維持反射率最 商値時的局反射率。 10 木紙張尺度適用^國國家標準（CNS)A4規格（210 X 297公釐) ""' (請先閱讀背面之注意事項再填寫本頁)Lal · -line 561280 A7 ____B7__ __ 5. Explanation of the invention (1) The situation has the same result. On the other hand, it can be seen from FIG. 7 that when the incident wavelength is fixed, once the period is changed, the incident angle at which the reflectance reaches the highest value changes. Therefore, even if the fixed period is long and Γ is changed, the incident angle at which the reflectance corresponding to the fixed incident wavelength reaches the highest value will be changed. As long as this feature is used, even if the period of the multilayer film is kept the same, by selecting Γ, the angle of incidence of each point in the reflecting mirror surface will be the angle of maximum reflectance corresponding to a fixed incident wavelength. The figure shown in Fig. 9 shows the relative graph of the reflectance and the angle of incidence when Γ 値 is changed. The horizontal axis is the angle of incidence and the vertical axis is the reflectivity. In this figure, the light is incident on a Mo / Si multilayer film with a period of 69A and a layer number of 50 and a wavelength of 13.36mn. Each line in the figure indicates the one established after changing Γ 値. It can be seen from this figure that by changing Γ 値, the angle of incidence that maximizes the reflectance 値 can be changed. That is, when Γ is 0.5, the angle of incidence with the highest reflectance 値 is about 4 °, but when Γ is 0.3, it is about 10 °. As Γ 値 decreases, the angle of incidence with the highest reflectance 则Increasing from 0 °. Therefore, Γ 値, which maximizes the reflectance, can be selected according to the incident angle, thereby obtaining the quotient reflectance. For example, when the incident angle is between 0 ° and 5 °, Γ = 0.45 can get the highest reflectance; between 5 ° and 8 °, Γ = 0.4 can get the highest reflectance; between 8 ° and 10 °, Γ = 0.35 gives the highest reflectivity. Furthermore, it is preferable to control Γ in the range of 0.3 to 0.5 to maintain the local reflectance at the time when the reflectance is the best quotient. 10 Wood paper size applies to ^ National Standard (CNS) A4 (210 X 297 mm) " " '(Please read the precautions on the back before filling this page)
561280 A7 __B7___ 五、發明說明（Z ) (請先閱讀背面之注意事項再填寫本頁) 又，此圖的Γ値雖以0.05的刻度値進行改變，然而， 欲謀求最適化時，若能使Γ値呈連續變化則更佳。如所述 ，欲選擇最佳的Γ値時，乃延著圖9的曲線之高反射率側 的包絡線，使入射角度對應於Γ値。藉此，當入射光的波 長爲13.6nm，週期長保持爲69A時，在入射角度爲0°至 10°的範圍內，可使反射率値在約72.5%至約74%之間變 化，而將反射率的下降程度控制在1%。 欲保持多層膜的週期長爲定値而改變Γ値，有同時變 化Mo層本身的膜厚分布以及Si層本身的膜厚分布之作法 。以往之膜厚分布修正，乃是保持Γ於可獲高反射率之値 的狀況下，來對整體的膜厚進行所需的分布。其方法包含 了在濺渡法中改變濺鍍條件或成膜基板（反射鏡）的傾斜 角度等之成膜條件來控制飛散粒子分布之方法；或是藉遮 蔽板來控制飛散粒子的分布之膜厚修正遮罩的方法。此類 方式亦可應用於本發明中用來分布Γ的方法。 圖1係本發明之實施形態的多層膜反射鏡之結構圖， 圖1(A)爲整體結構之截面示意圖，（B)乃是將此多層膜反射 鏡之任意1層對水平化之後所得截面圖。 圖2所示者，係搭載了圖1的多層膜反射鏡之X射線 曝光裝置的整體結構圖。 首先參照圖2來說明X射線曝光裝置的槪要。 此種X射線曝光裝置，係以波長13nm附近的軟X射 線區域的光（以下稱爲EUV光）作爲曝光用的照明光，且 以步進掃描方式來進行曝光動作。 11 本、紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 561280 A7 ____B7__ 五、發明說明（1 ) --------------裝--- (請先閱讀背面之注意事項再填寫本頁) X射線曝光裝置1的最上層，配置著雷射光源3。雷 射光源3具有供給從紅外線至可見光區域之波長的雷射光 的機能，可使用如YAG雷射或準分子雷射等由半導體雷射 所激發而得者。由雷射光源3所發出的雷射光’藉聚光光 學系統5而聚光’進而到達配置於下部之雷射電漿光源7 。雷射電漿光源7 ’可高效率地產生波長13mn附近的X 射線。 -線· 雷射電漿光源7,乃配置有未圖示之噴嘴以噴出氙氣 。所噴出的氙氣在雷射電漿光源7接受到高照度的雷射光 。因高照度的雷射光之能量致使氙氣轉爲高溫，乃被激發 成電漿狀態，並在轉移至低能階狀態時放出EUV光。因 EUV光對大氣的穿透率低，其光路遂由反應室（真空室）9 所覆蓋來阻絕外部氣體。再者，因爲放出氙氣的噴嘴產生 殘質(debds)，因而，除反應室9外另需設置其他的反應室 〇 在雷射電漿光源7的上端，配置有已塗佈Mo/Si層多層 膜之旋轉拋物面反射鏡11，從雷射電漿光源7所幅射的X 射線入射至拋物面反射鏡11，僅將波長13nm附近的X射 線平行地朝曝光裝置1的下方反射。 在旋轉拋物面反射鏡11的下方，配置了由厚度 0.15nm的Be(鈹)所構成的可見光阻隔X射線穿透濾鏡13 。從拋物面反射鏡11所反射的X射線，僅有所需的13nm 的X射線得通過穿透濾鏡13。穿透濾鏡13附近係由反應 室15所覆蓋而阻絕外部氣體。 12 木紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 561280 A7 ___-____B7 _ _ 五、發明說明（I ° ) ----------------- (請先閱讀背面之注意事項再填寫本頁) 穿透濾鏡13的下方，設置有曝光反應室33。在曝光 反應室33內的穿透濾鏡π之下方，配置有照明光學系統 17 °照明先學系統17 ’係由聚光系統的反射鏡、複眼光學 系統的反射鏡所構成，將從穿透濾鏡13入射的X射線調 整爲圓弧狀，朝圖的左方照射。 照明光學系統17的圖的左方，配置有X射線反射鏡 19。X射線反射鏡19，在圖的右側之反射面19a具有內凹 的圓形旋轉拋物圓鏡，且藉保持構件來維持垂直狀。X射 線反射鏡19，其反射面19a係由高精度加工的石英基板所 構成。在反射面19a，形成了對波長13nm之X射線具高 反射率的Mo與Si之多層膜。又，使用波長10〜15nm的X 射線時，亦得採用由Ru(釕）、Rh(鍺)等物質，與Si、Be(鈹 )、B4C(四硼化碳)等物質所組合而得之多層膜。 -線 X射線反射鏡19的圖右方，係斜向配置了光路轉折 反射鏡21。在光路轉折反射鏡21的上方，使反射型光罩 23的反射面朝下且以水平配置。從照明光學系統17所釋 放出的X射線，藉著X射線反射鏡19而反射聚光之後， 透過光路轉折反射鏡21，到達反射型光罩23的反射面。 反射型光罩23的反射面亦形成有由多層膜而構成的 反射膜。此反射膜具有與欲轉印在晶圓29的圖案相對應的 光罩圖案。在反射型光罩23的上方固定有圖示的光罩平台 25。光罩平台25至少可朝Y方向移動’俾將從光路轉折 反射鏡21所反射的X射線依序照射在光罩23上。 在反射型光罩23的下方’依序配置有投影光學系統 13 木紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 561280 A7 _ B7____ 五、發明說明（、\) ----------------- (請先閱讀背面之注意事項再填寫本頁) 27、晶圓29。投影光學系統27，係由複數的反射鏡等所組 成，將反射型光覃23上的圖案以特定的縮小倍率（例如 1/4)予以縮小後，在晶圓29上成像。晶圓29，係被可朝 XYZ方向移動的晶圓平台31所吸附而固定住。 曝光反應室33係透過聞形閥35與預備排氣室37(加 載互鎖真空反應室）相連。預備排氣室37接連了真空泵 39，藉真空泵39的運轉使預備排氣室37得進行真空排氣 〇 .線 在進行曝光動作之際，乃是藉照明光學系統17將 EUV光照射在反射型光罩23的反射面。此時，係使反射 型光罩23及晶圓29以投影光學系統的縮小倍率所決定之 特定速度比來與反射投影光學系統27進行相對的同步掃描 。藉此，將反射型光罩23的整體電路圖案藉著步進掃描方 式來分別轉印在晶圓29上的複數之曝光區域。又，晶圓 29之晶片爲25 X 25nm見方，且可在光阻上曝光0.07// mL/S之1C圖案。 其次參照圖1來說明本發明之實施形態裡的多層膜反 射鏡之結構。 此發明之多層膜反射鏡，係使用在圖2的X射線曝光 裝置之旋轉拋物面反射鏡19或X射線反射鏡11。 多層膜反射鏡50，係讓以Mo層56與Si層57爲一 對之週期長69A的Mo/Si多層膜之層對在具凹狀表面的 基板55上積層5〇層者。入射至該多層膜反射鏡50的光線 之入射角度，在圖的區域51之中爲〇°至5° ;在區域52 14 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 561280 A7 __—____B7 五、發明說明（，） 之中爲5°至8° ;在區域53之中爲8。至10。。 此多層膜的1層ΐί之中’對Mo層56與Si層57的厚 度設計，乃是使區域51的Γ値爲〇·45、區域52的Γ値爲 〇·4 ,區域53的Γ値爲0.3。此等Γ値可藉由上述圖9而得 〇 因爲係藉上述方法而形成多層膜之故，在入射角度爲 0°至10°之間可將反射率的衰減控制在1%左右。 再者，此種多層膜的製作可藉由離子濺鍍法，將Mo 用及Si用之個別的飛散粒子修正板使用在形成各層之形成 時。 圖3所示者，乃是本發明的其他實施形態中，將其多 層膜反射鏡的任一層對予以水平化後所得之截面圖。 此例之多層膜亦具備與圖1之多層膜的相同結構。入 射至該多層膜反射鏡的光線之入射角度，係從基板的中心 朝向外周呈0°至10°的連續分布。 此種多層膜的1層對之中，係以使Γ値從基板中心部 朝向外周呈0.45至0.35的連續分布的方式來設計Mo層 56與Si層57之厚度。又，對基板上的各點之Γ値的選擇 ’必須是在各點的入射角度具備最高反射率者。 藉此法形成多層膜，可使得入射角度範圍從0。至10 °之間時，反射率的衰減得控制在1%左右。 再者，此種多層膜的製作，可藉由離子濺鍍法，將 Mo用及Si用之個別的飛散粒子修正板使用在形成各層之 時。 15 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 裝 上-δ · ，線 561280 A7 ___B7___ 五、發明說明（A ) ,---------------- (請先閱讀背面之注意事項再填寫本頁) 圖4所示者，乃是本發明之其他實施形態的多層膜反 射鏡之結構圖，（A)表整體結構之截面不意圖’（B)表將此 多層膜反射鏡的任一層對予以水平化後所得之截面圖。 此例之多層膜反射鏡80亦具備與圖1的多層膜反射 鏡之相同結構，係Mo層86與Si層87在基板85上交互 積層者。入射至此多層膜反射鏡80的光線之入射角度’係 從基板85的中心朝外周呈〇°到20°之大範圍分布，在區 域81的入射角度爲0°至，在區域82的入射角度爲 10°以上。 •線 在此種多層膜的1層對之中，在入射角度爲〇°至 。的區域81，係使Γ値的分布如同圖3的多層膜般，從中 心朝外周由0.45至0.35連續分布，來作爲Mo層86與Si 層87之厚度設計方式。倘對入射角度大於10°以上的區 域82再降低其Γ値，則Γ値將在〇·35以下，導致反射率 的降低。因此，在入射角度大的區域82，係藉以往的膜厚 變化來進行修正。亦即，在此區域乃使Γ値爲0.35之定値 而改變週期長。 如以上所述般，當入射角度的範圍較廣，存有僅憑Γ 値的分布仍無法對應的區域時，可對一部份實施以往之改 變週期長來作膜厚分布修正的作法。在此種情況下，膜厚 分布的變動量較以往全表面進行膜厚分布修正時爲少，故 能抑制光學性能的劣化。 此種多層膜的製作，可藉由離子濺渡法，將Mo用及 Si用之個別的分布修正板使用在形成各層之時。此時，可 16 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 561280 A7 __ B7_ 五、發明說明（K) 藉1個分布修正板，進行對區域的Γ値分布及膜厚分布。 ---------------- (請先閱讀背面之注意事項再填寫本頁) 圖5所示者，乃是本發明之其他實施形態的多層膜反 射鏡之結構圖，係將多層膜反射鏡的任一層對予以水平化 後所得之截面圖。 此例之多層膜反射鏡90亦具備與圖1的多層膜反射 鏡之相同結構，係Mo層96與Si層97所積層者。 在此多層膜的1層對之中，係使Γ値從基板中心朝外 周呈連續變化的同時亦使週期長呈連續變化。在此種應用 例時，與以往僅改變全表面的週期長來進行膜厚分布修正 相較，其反射率雖微幅下降，然而，卻能控制光學性能俾 使不致產生往常般的光學性能劣化之現象。此例與圖4之 多層膜反射鏡相較則頗具實用價値。 -線 如以上所述般，藉保持週期長於定値而改變Γ値來獲 得最大反射率的方法，尤適用在入射角度從0°至（10°的 範圍。當入射角度大於10°以上時，可藉由改變週期長， 形成在接近直向入射（入射角度爲0° )時的Γ値高達0.4 至0.45，距垂直入射較遠者降至〇·3至0.35之多層膜。 【發明效果】 由以上說明可明顯看出，若根據本發明，則可提供一 種不須改變多層膜的週期長即可獲得高反射率的多層膜反 射鏡。又，藉著此種多層膜反射鏡的使用，則能提供一種 光學性能不會劣化而能獲得高反射率的X射線曝光裝置。 【圖示之簡單說明】 圖1係本發明之實施形態的多層膜反射鏡之結構圖， 17 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公愛) ~ ' 561280 A7 ______B7_____ 五、發明說明（j) 圖1(A)表整體結構之截面示意圖，（B)表將該多層膜反射鏡 的任一層對予以水平化後所得之截面圖。 圖2係搭載有圖1的多層膜反射鏡之X射線曝光裝置 的整體結構圖。 圖3係將本發明之他項實施形態的多層膜反射鏡之任 一層對予以水平化後所得之截面圖。 圖4係本發明之另一項實施形態的多層膜反射鏡之結 構圖，（A)爲整體結構之截面示意圖，（B)係將此多層膜反 射鏡的任一層對予以水平化後所得之截面圖。 圖5係本發明之又一項實施形態的多層膜反射鏡之結 構圖，乃是將此多層膜反射鏡的任一層對予以水平化後所 得之截面圖。 圖6係反射率對入射角度的關係圖。 圖7係表入射光的波長爲13.36nm時，其反射率達最 高値的週期長及膜厚（週期長X層對數）相對於入射角度 的關係圖。 圖8係入射波長與反射率的關係圖。 圖9係改變Γ値時所得之反射率對入射角度之圖。 "【元件符號說明】 1·Χ射線曝光裝置 3.雷射光源 5·聚光光學系統 7·雷射電漿光源 9.反應室 18 _ 衣紙張尺度適用中國國家標準（CNS)A4規格（210 x 297公釐） (請先閱讀背面之注意事項再填寫本頁)561280 A7 __B7___ V. Description of the invention (Z) (Please read the notes on the back before filling this page) Also, although Γ 値 in this figure is changed on a scale of 0.05, however, if you want to optimize, if you can make It is more preferable that Γ 値 changes continuously. As described above, when the optimal Γ 値 is to be selected, the envelope of the high reflectance side of the curve in FIG. 9 is extended so that the incident angle corresponds to Γ 値. With this, when the wavelength of the incident light is 13.6nm and the period is maintained at 69A, the reflectance 値 can be changed between about 72.5% and about 74% in the range of the incident angle of 0 ° to 10 °, and The degree of decrease in reflectivity was controlled to 1%. In order to keep the cycle length of the multilayer film constant and change Γ 値, there are methods of simultaneously changing the film thickness distribution of the Mo layer itself and the film thickness distribution of the Si layer itself. In the past, the correction of the film thickness distribution is to maintain the Γ at a condition where a high reflectance can be obtained, so as to perform a desired distribution on the overall film thickness. The method includes a method of controlling the distribution of scattered particles by changing the sputtering conditions or the film forming conditions such as the inclination angle of the film-forming substrate (reflector) in the sputtering method; or a film that controls the distribution of scattered particles by a shielding plate. Method for thick correction mask. This method can also be applied to the method for distributing Γ in the present invention. FIG. 1 is a structural diagram of a multilayer film reflector according to an embodiment of the present invention. FIG. 1 (A) is a schematic cross-sectional view of the overall structure, and (B) is a cross-section obtained by horizontalizing any one layer pair of the multilayer film reflector. Illustration. The one shown in Fig. 2 is an overall configuration diagram of an X-ray exposure apparatus equipped with the multilayer film mirror of Fig. 1. First, the outline of the X-ray exposure apparatus will be described with reference to FIG. 2. Such an X-ray exposure apparatus uses light in a soft X-ray region (hereinafter referred to as EUV light) having a wavelength of about 13 nm as illumination light for exposure, and performs an exposure operation in a step-and-scan method. 11 The size of this paper is in accordance with the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 561280 A7 ____B7__ V. Description of the invention (1) -------------- Installation --- ( (Please read the precautions on the back before filling in this page.) The top layer of the X-ray exposure device 1 is equipped with a laser light source 3. The laser light source 3 has a function of supplying laser light having a wavelength ranging from infrared to visible light, and a semiconductor laser can be used such as a YAG laser or an excimer laser. The laser light ' emitted from the laser light source 3 is condensed ' by the concentrating optical system 5 and then reaches the laser plasma light source 7 arranged at the lower portion. The laser plasma light source 7 'can efficiently generate X-rays having a wavelength of around 13mn. -Linear plasma light source 7 is equipped with a nozzle (not shown) to emit xenon gas. The emitted xenon gas receives laser light of high illuminance at the laser plasma light source 7. The energy of the high-intensity laser light causes the xenon gas to turn to a high temperature, but it is excited into a plasma state and emits EUV light when it transitions to a low-energy state. Because EUV light has a low permeability to the atmosphere, its optical path is covered by a reaction chamber (vacuum chamber) 9 to block external air. In addition, since the nozzle emitting xenon gas generates debds, it is necessary to set up other reaction chambers in addition to the reaction chamber 9. On the upper end of the laser plasma light source 7, a coated Mo / Si layer multilayer film is arranged. The rotating parabolic mirror 11 enters the parabolic mirror 11 from the X-rays radiated from the laser plasma light source 7 and reflects only the X-rays having a wavelength of about 13 nm in parallel toward the lower side of the exposure device 1. Below the rotating parabolic mirror 11, a visible light blocking X-ray transmission filter 13 made of Be (beryllium) having a thickness of 0.15 nm is arranged. For the X-rays reflected from the parabolic mirror 11, only the required X-rays of 13 nm have to pass through the transmission filter 13. The vicinity of the penetration filter 13 is covered by the reaction chamber 15 to block external air. 12 Wood paper scale is applicable to China National Standard (CNS) A4 (210 X 297 mm) 561280 A7 ___-____ B7 _ _ 5. Description of the invention (I °) --------------- -(Please read the precautions on the back before filling this page.) Below the penetration filter 13, an exposure reaction chamber 33 is set. Below the penetration filter π in the exposure reaction chamber 33, an illumination optical system 17 ° is provided. The illumination learning system 17 'is composed of a reflector of a condenser system and a reflector of a compound eye optical system. The X-rays incident on the filter 13 are adjusted in an arc shape, and irradiated toward the left side of the figure. On the left side of the figure of the illumination optical system 17, an X-ray mirror 19 is arranged. The X-ray reflecting mirror 19 has a concave circular rotating parabolic mirror on a reflecting surface 19a on the right side of the figure, and maintains a vertical shape by a holding member. The X-ray reflecting mirror 19 has a reflecting surface 19a made of a quartz substrate processed with high accuracy. On the reflecting surface 19a, a multilayer film of Mo and Si having high reflectance to X-rays having a wavelength of 13 nm is formed. In addition, when using X-rays with a wavelength of 10 to 15 nm, it can also be obtained by combining materials such as Ru (ruthenium) and Rh (germanium) with materials such as Si, Be (beryllium), B4C (carbon tetraboride), and the like. Multilayer film. The right-hand X-ray mirror 19 is provided with an optical path turning mirror 21 diagonally. Above the optical path turning mirror 21, the reflective surface of the reflective mask 23 is arranged downward and horizontally. The X-rays emitted from the illumination optical system 17 are reflected and condensed by the X-ray mirror 19, and then transmitted through the optical path turning mirror 21 to reach the reflection surface of the reflective mask 23. The reflective surface of the reflective mask 23 is also formed with a reflective film composed of a multilayer film. This reflective film has a mask pattern corresponding to the pattern to be transferred on the wafer 29. A photomask stage 25 shown in the figure is fixed above the reflective photomask 23. The mask stage 25 can be moved at least in the Y direction ', and X-rays reflected from the light path turning mirror 21 are sequentially irradiated onto the mask 23. Below the reflective mask 23, a projection optical system is arranged in order. 13 The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 561280 A7 _ B7____ 5. Description of the invention (, \)- --------------- (Please read the precautions on the back before filling this page) 27. Wafer 29. The projection optical system 27 is composed of a plurality of mirrors, etc., and reduces the pattern on the reflective light beam 23 at a specific reduction ratio (for example, 1/4), and then forms an image on the wafer 29. The wafer 29 is fixed by being held by a wafer stage 31 that can be moved in the XYZ direction. The exposure reaction chamber 33 is connected to a pre-exhaust chamber 37 (load interlocking vacuum reaction chamber) through a smell valve 35. The pre-exhaust chamber 37 is connected to a vacuum pump 39. The pre-exhaust chamber 37 is evacuated by the operation of the vacuum pump 39. When the line is exposed, the illumination optical system 17 is used to illuminate the EUV light in a reflective type. The reflecting surface of the photomask 23. At this time, the reflective mask 23 and the wafer 29 are scanned synchronously with the reflective projection optical system 27 at a specific speed ratio determined by the reduction ratio of the projection optical system. Thereby, the entire circuit pattern of the reflective mask 23 is transferred to a plurality of exposed areas on the wafer 29 in a step-and-scan manner. In addition, the wafer of wafer 29 is 25 × 25nm square, and the 1C pattern of 0.07 // mL / S can be exposed on the photoresist. Next, the structure of a multilayer film reflector according to an embodiment of the present invention will be described with reference to FIG. The multilayer film mirror of the present invention is a rotating parabolic mirror 19 or an X-ray mirror 11 used in the X-ray exposure apparatus of Fig. 2. The multilayer film reflecting mirror 50 is a layer of a Mo / Si multilayer film having a period of 69A with the Mo layer 56 and the Si layer 57 as a pair, and 50 layers are laminated on the substrate 55 having a concave surface. The angle of incidence of the light incident on the multilayer film reflector 50 is 0 ° to 5 ° in the area 51 in the figure; in the area 52 14 the size of the paper is applicable to the Chinese National Standard (CNS) A4 (210 X 297 mm) ) 561280 A7 __—____ B7 5. In the description of the invention (,), it is 5 ° to 8 °; in area 53, it is 8. To 10. . The thickness design of the Mo layer 56 and Si layer 57 in one layer of this multilayer film is such that Γ 値 in the area 51 is 0.45, Γ 値 in the area 52 is 0.4, and Γ 値 in the area 53 Is 0.3. These Γ 値 can be obtained from the above-mentioned FIG. 9. Because the multilayer film is formed by the above method, the attenuation of the reflectance can be controlled at about 1% between the incidence angle of 0 ° and 10 °. In addition, for the production of such a multilayer film, individual scattered particle correction plates for Mo and Si can be used in the formation of each layer by the ion sputtering method. Fig. 3 is a cross-sectional view of another embodiment of the present invention in which any one of a pair of multilayer mirrors is horizontalized. The multilayer film of this example also has the same structure as the multilayer film of FIG. 1. The incident angle of the light incident on the multilayer film reflector is a continuous distribution from 0 ° to 10 ° from the center of the substrate toward the outer periphery. The thickness of the Mo layer 56 and the Si layer 57 is designed so that Γ 对 is continuously distributed from the center of the substrate toward the outer periphery from 0.45 to 0.35 in one layer of such a multilayer film. The selection of Γ 値 at each point on the substrate must be selected so as to have the highest reflectance at the incident angle of each point. By forming a multilayer film by this method, the incident angle range can be from 0. When the temperature is between 10 ° and 10 °, the attenuation of the reflectivity is controlled to about 1%. In addition, in the production of such a multilayer film, individual scattered particle correction plates for Mo and Si can be used for forming each layer by the ion sputtering method. 15 The size of the paper is applicable to the Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling out this page) Install -δ ·, line 561280 A7 ___B7___ V. Description of the invention (A) , ---------------- (Please read the precautions on the back before filling out this page) The one shown in Figure 4 is the multilayer film reflector of another embodiment of the present invention. Structure diagram, (A) shows the cross-section of the overall structure is not intended. (B) shows a cross-sectional view obtained by horizontalizing any layer pair of this multilayer film reflector. The multilayer film mirror 80 of this example also has the same structure as the multilayer film mirror of FIG. 1, and is a layer in which a Mo layer 86 and a Si layer 87 are alternately laminated on a substrate 85. The angle of incidence of the light incident on the multilayer film reflector 80 is distributed from the center of the substrate 85 to the outer periphery in a wide range of 0 ° to 20 °. The incidence angle in the region 81 is 0 ° and the incidence angle in the region 82 is Above 10 °. • Line In a 1-layer pair of this multilayer film, the angle of incidence is 0 ° to. The region 81 of γ is the same as the multilayer film of FIG. 3, and is continuously distributed from the center to the periphery from 0.45 to 0.35 as the thickness design method of the Mo layer 86 and the Si layer 87. If Γ 値 is further reduced for an area 82 with an incident angle greater than 10 °, Γ 値 will be below 0.35, resulting in a decrease in reflectance. Therefore, in the region 82 where the incident angle is large, correction is performed based on the conventional film thickness change. That is, in this region, the change cycle is long with Γ 値 being 0.35. As described above, when the range of incident angles is wide and there is a region that cannot be corresponded only by the distribution of Γ 値, a part of the conventional method can be implemented to modify the film thickness distribution. In this case, since the variation amount of the film thickness distribution is smaller than when the film thickness distribution correction is performed on the entire surface in the past, deterioration of optical performance can be suppressed. For the production of such a multilayer film, individual distribution correction plates for Mo and Si can be used for forming each layer by the ion sputtering method. At this time, 16 paper sizes can be applied to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 561280 A7 __ B7_ V. Description of the invention (K) Borrow a distribution correction board to perform Γ 値 distribution and Film thickness distribution. ---------------- (Please read the precautions on the back before filling out this page) The one shown in Figure 5 is the structure of a multilayer film reflector according to another embodiment of the present invention. The figure is a cross-sectional view obtained by horizontalizing any pair of layers of a multilayer film reflector. The multilayer film mirror 90 of this example also has the same structure as the multilayer film mirror of FIG. 1, and is a layer in which a Mo layer 96 and a Si layer 97 are laminated. In the one-layer pair of the multilayer film, Γ 値 is continuously changed from the center of the substrate to the periphery, and the cycle length is also continuously changed. In this application example, compared with the conventional method of correcting the film thickness distribution only by changing the period of the entire surface, the reflectance is slightly reduced, but it can control the optical performance so as not to cause ordinary optical performance degradation. Phenomenon. This example is quite practical compared with the multilayer film mirror of Fig. 4. -As mentioned above, the method of obtaining maximum reflectance by changing Γ 値 by keeping the period longer than fixed 値 is particularly suitable for the range of incident angles from 0 ° to (10 °. When the incident angle is greater than 10 °, By changing the length of the period, a multilayer film with a Γ 値 as high as 0.4 to 0.45 when approaching direct incidence (incidence angle of 0 °) and a distance farther from normal incidence is reduced to 0.3 to 0.35. [Effect of the Invention] By It is obvious from the above description that according to the present invention, it is possible to provide a multilayer film reflector that can obtain high reflectance without changing the long period of the multilayer film. Furthermore, by using such a multilayer film reflector, It can provide an X-ray exposure device that can obtain high reflectivity without deteriorating optical performance. [Simplified illustration of the figure] FIG. 1 is a structural diagram of a multilayer film reflector according to an embodiment of the present invention. National Standard (CNS) A4 specification (210 X 297 public love) ~ '561280 A7 ______B7_____ V. Description of the invention (j) Figure 1 (A) is a schematic cross-sectional view of the overall structure. (B) One layer The cross-sectional view obtained after flattening. Fig. 2 is an overall structural diagram of an X-ray exposure apparatus equipped with the multilayer film reflector of Fig. 1. Fig. 3 is a pair of layers of a multilayer film reflector according to another embodiment of the present invention. The cross-sectional view obtained after leveling. Figure 4 is a structural diagram of a multilayer film mirror according to another embodiment of the present invention, (A) is a schematic cross-sectional view of the overall structure, and (B) is a schematic view of the multilayer film mirror. A cross-sectional view obtained by leveling any pair of layers. Figure 5 is a structural diagram of a multilayer film reflector according to another embodiment of the present invention, which is obtained by leveling any pair of layers of this multilayer film reflector Cross-sectional view. Figure 6 shows the relationship between reflectance and incident angle. Figure 7 shows the period and film thickness (period length X layer logarithm) of the maximum reflectance when the incident light has a wavelength of 13.36nm relative to the incidence. Angle relationship diagram. Figure 8 is the relationship between the incident wavelength and the reflectance. Figure 9 is the graph of the reflectance vs. the angle of incidence obtained by changing Γ 値. &Quot; [Explanation of the symbol of the element] 1 · X-ray exposure device 3.Ray Spot light source 5 · Spotlight · Laser plasma light source system 7 9. reaction chamber 18 _ clothes paper scale applicable Chinese National Standard (CNS) A4 size (210 x 297 mm) (Please read the back of the precautions to fill out this page)
561280 A7 _ B7_ 五、發明說明（> ) (請先閱讀背面之注意事項再填寫本頁) 11.旋轉拋物面反射鏡 13.X射線穿透濾鏡 15.反應室 17.照明光學系統 19.X射線反射鏡 21.光路轉折反射鏡 23.反射型光罩 25.光罩平台 27.投影光學系統 29.晶圓 31.晶圓平台 33.曝光反應室 35.閘形閥 37.預備排氣室（加載互鎖真空反應室） 39.真空栗 50,80,90 多層膜反射鏡 51，52,53,81，82 區域 55,85 基板 56.86.96 Mo 層 57.87.97 Si 層 木紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）561280 A7 _ B7_ V. Description of the invention (>) (Please read the precautions on the back before filling this page) 11. Rotating parabolic mirror 13. X-ray transmission filter 15. Reaction chamber 17. Lighting optical system 19. X-ray mirror 21. Light path turning mirror 23. Reflective mask 25. Mask platform 27. Projection optical system 29. Wafer 31. Wafer platform 33. Exposure reaction chamber 35. Gate valve 37. Preparing exhaust Chamber (loading interlocking vacuum reaction chamber) 39. Vacuum pump 50, 80, 90 multilayer film reflectors 51, 52, 53, 81, 82 area 55, 85 substrate 56.86.96 Mo layer 57.87.97 Si layer wood paper scale applicable China National Standard (CNS) A4 specification (210 X 297 mm)