TW200528941A - Image balance method for phase shifting mask - Google Patents

Abstract

A method utilizes two masking writing to form a non-etched phase shift opening on the transparent substrate, and an undercut structure in the transparent substrate, such that the depth corresponds to a phase shift of 180 degrees between the non-etched phase shift opening and the undercut structure when the exposing light source illuminates the undercut structure and non-etched shift opening. Furthermore, the intensities for the light source illuminates the undercut structure and the non-etched phase shift opening is equally, such that the image can be balanced to transfer onto the wafer when the patterning process is performed.

Description

200528941 五、發明說明（1) ' ' ~ ~ 一、【發明技術領域】 本發明係有關於一種利用兩次光罩寫入的方式，以形 成具平衡影像之圖案於晶片上，更特地是利用底切結構以 及偏斜圖案的方式，產生具平衡的影像圖案於晶片上。 二、【先前技術】 在積體電路中，對於光學 由高積密度以及高的執行速度 一連串的細小尺寸而可以得到 的關鍵尺寸可以藉由晶片的步 的波長成正比’而與投射透鏡 Aperture (NA))成反比。然而 衍射現象（di f fraction)的發 光源的波長。其中，所減少的 ’且此光罩是藉由晶片步進機 的光阻。 微影製程的改進，已經可以 得到，且藉由積體電路元件 。根據Rayleigh準則，最小 進機（stepper)與照射光源 的數值孔徑（Numerical ’在照射晶片的過程中會有 生，此衍射現象會減少照射 波長係為位於光罩上的波長 ’並選擇性地曝光在底材上 〜光學微影在次波長的情況下會有益於具有解析度增強 技術（Resolution Enhancement Techniques (RETs))，例 如，相位移光罩可以得到較寬的製程曝光寬容度 (jatitude)。不像傳統的二次光罩（binary只能調 ^先源的振幅（amplitude)，而相位移光罩可以控制光源 Ϊ Ϊ认以得到破壞性干涉’而減少衍射現象所產生的影 0 。4於圖案化較小的關鍵尺寸時，間隔式相位移光罩 第5頁 200528941 五、發明說明（2) ~一 ' (Alternating PSM (AltPSM))是較常使用的一種方法，例 如，對於在積體電路元件上，電晶體的閘極的圖案化。間 隔式相位移光罩增加在穿透過鄰近清楚開口之間的18〇度 相位’以使得在兩個圖案之間的振幅為〇。 光路路徑（optical path length)透過位於不透明層 中的鄰近開口可以產生180度相位移的差異性，其中，不 透明層為鉻（chrome)。另一額外的製程係在間隔式開口中 移除透明層之後進行，其步驟包含沉積一透明層，例如旋 塗式玻璃，經由在鉻層内的開口至透明底材上，此透明底 材可以是炼化矽或是石英。然而，此額外的製程容易受到 在光路以及在干涉中所產生的失真，使得材料的光學特性 不能配合，而產生問題。因此，在石英底材内且利用間隔 式開口的方式來蝕刻溝渠是最常使用的解決方式。 然而’間隔式相位移光罩在底切底材的製程中，會造 成曝光光源照射底切結構時，產生散射現象至蝕刻開口的 側壁以及底層的角落。波導（waveguide)效應會產生不平 衡的虛擬圖像（aerial image imbalance)，此不平衡虛擬 圖像是由於關鍵尺寸的誤差，以及圖案位置的誤差所造成 的。因此，蝕刻開口的關鍵尺寸比未蝕刻開口的臨界開口 小。位於兩個開口之間的寬度顯示出，未蝕刻開口的位置 或寬度會朝向蝕刻開口移動。因此，為了得到平衡之影像 ’以下有幾種習知的解決方式。200528941 V. Description of the invention (1) '' ~ ~ 1. [Technical Field of the Invention] The present invention relates to a method of using two photomasks to form a pattern with a balanced image on a wafer. More specifically, it uses The undercut structure and skewed pattern produce a balanced image pattern on the wafer. 2. [Previous technology] In integrated circuits, the critical size that can be obtained for a series of small sizes of optics from high product density and high execution speed can be proportional to the wavelength of the step of the wafer 'and is the projection lens Aperture ( NA)). However, the wavelength of the light source of the di f fraction. Among them, the reduced photoresist is a photoresist by a wafer stepper. Improvements in the lithography process are already available, and with integrated circuit components. According to the Rayleigh criterion, the minimum stepper and the numerical aperture of the illumination source (Numerical 'will occur during the process of irradiating the wafer. This diffraction phenomenon will reduce the irradiation wavelength to the wavelength located on the mask' and selectively expose it. On the substrate ~ Optical lithography will benefit from having Resolution Enhancement Techniques (RETs) in the case of sub-wavelengths. For example, a phase shift mask can get a wider process exposure jatitude. Unlike the traditional secondary mask (binary can only adjust the amplitude of the first source), the phase shift mask can control the light source Ϊ to identify destructive interference 'and reduce the shadow produced by the diffraction phenomenon. 4 When patterning smaller key dimensions, the spacer phase shift mask is provided. Page 5 200528941 V. Description of the Invention (2) ~ One '(Alternating PSM (AltPSM)) is a commonly used method. For example, The patterning of the gate of the transistor on the body circuit element. The spaced phase shift mask increases the phase of 180 degrees between the adjacent clear openings so that in two patterns The amplitude between them is 0. The optical path length can produce a 180-degree phase shift difference through an adjacent opening in the opaque layer, where the opaque layer is chrome. Another additional process is in the interval After the transparent layer is removed from the opening, the step includes depositing a transparent layer, such as spin-on glass, through the opening in the chromium layer to the transparent substrate. The transparent substrate may be refined silicon or quartz. However, this additional process is susceptible to distortions in the optical path and interference, making the optical characteristics of the material unsuitable and causing problems. Therefore, the use of spaced openings in the quartz substrate to etch trenches is the most important. Frequently used solutions. However, in the process of undercutting the substrate, the interval phase shift mask can cause scattering when the exposure light source irradiates the undercut structure to the side walls and corners of the etching opening. Waveguide The effect will produce an imbalanced virtual image (aerial image imbalance), which is due to a critical size error And the pattern position error. Therefore, the critical size of the etched opening is smaller than the critical opening of the unetched opening. The width between the two openings shows that the position or width of the unetched opening will move toward the etched opening. In order to get a balanced image 'There are several conventional solutions below.

200528941 五、發明說明（3) 第一A圖至第一C圖，表示傳統光學微影技術中，曝光 光源照射餘刻開口’產生散射現象（s c a 11 e r i n g )，而造成 光源強度與未蝕刻開口不相等之形成步驟示意圖。如第一 A圖，首先在透明底材1 〇 0上形成一不透明層丨〇 2，然後利 用傳統的微影步驟，餘刻不透明層1 〇 2，以形成一第一開 口 104以及第二開口 1〇6，其中，位於透明底材1〇〇上方的 不透明層102將第一開口 1〇4與第二開口 1〇6分開，且第一 開口104可以稱為非钱刻開口（n〇n_etched 0pening)，而 第一開口 106可以稱為姓刻開口（etched 0pening)。 在第一β圖中，一光阻層11〇覆蓋在部份的不透明層 102上方’以及第一開口 1〇4的上方。接著，如第一c圖所 示，以等向性姓刻的方式，經由第二開口丨〇 6蝕刻透明底 材1 0 0，在不透明底材1 〇 〇内形成第三開口丨丨2。此第三開 口112可以稱蝕刻相位移開口（etched phase shift opening)，而相對應於姓刻相位移開口丨丨2之第一開口 104，則可以稱為非蝕刻相位移開口（n〇n —etched shift opening)。在此，在透明底材1〇〇内的第三開口ιΐ2 具有一深度114，此深度114在第一開口（非蝕刻相位移開 口）104與第三開口（蝕刻相位移開口）112之間可以產生丨8〇 度的相位（phase)。 第一 D圖是表示曝光光源同時照射第一c圖中的第三開200528941 V. Description of the invention (3) Figures A through C show the traditional optical lithography technique. The exposure light source irradiates the openings at the rest of the time to produce a scattering phenomenon (sca 11 ering), resulting in light source intensity and unetched openings. Illustration of unequal formation steps. As shown in the first diagram A, an opaque layer 丨 02 is first formed on a transparent substrate 100, and then the opaque layer 1 〇 2 is formed by a conventional lithography step to form a first opening 104 and a second opening. 106, wherein the opaque layer 102 above the transparent substrate 100 separates the first opening 104 from the second opening 106, and the first opening 104 may be referred to as a non-money opening (non_etched 0pening), and the first opening 106 may be referred to as a last name etched opening. In the first beta diagram, a photoresist layer 110 covers a portion of the opaque layer 102 'and a portion of the first opening 104. Next, as shown in the first c diagram, the transparent substrate 100 is etched through the second opening 006 in the manner of an isotropic surname engraving, and a third opening 丨 2 is formed in the opaque substrate 100. The third opening 112 may be referred to as an etched phase shift opening, and the first opening 104 corresponding to the last name etched phase shift opening 2 may be referred to as a non-etched phase shift opening (n〇n — etched shift opening). Here, the third opening ιΐ2 in the transparent substrate 100 has a depth 114, and the depth 114 may be between the first opening (non-etching phase shift opening) 104 and the third opening (etching phase shift opening) 112. A phase of 80 degrees is generated. The first D image shows that the exposure light source simultaneously irradiates the third image in the first c image.

200528941 五、發明說明（4) 口 11 2，以及第一開口 1 0 4時’所產生的光源強度之示意圖 。由於第三開口 11 2經由曝光光源照射之後，會有散射現 象（scattering)產生，此散射現象會造成第一開口104與 第三開口 11 2的光強度不同。因此，不同的光源強度，在 圖案轉移到晶片上時，造成晶片上的圖案解析度不佳、圖 案的位置以及相位會有誤差產生。因此，對於整個晶片的 微影製程來說是必需要解決的一個問題。200528941 V. Description of the invention (4) Schematic diagram of the light source intensity generated by the opening 11 2 and the first opening 104. Since the third opening 11 2 is irradiated by the exposure light source, scattering will occur. This scattering phenomenon will cause the light intensity of the first opening 104 and the third opening 112 to be different. Therefore, when the light source intensity is different, when the pattern is transferred to the wafer, the resolution of the pattern on the wafer is poor, and the position and phase of the pattern may be incorrect. Therefore, it is a problem that must be solved for the lithography process of the entire wafer.

在第二A圖至第二C圖是表示利用兩次蝕刻步驟，形成 蝕刻相位移開口之步驟示意圖。與第一 A圖相同，在第二A 圖中，在透明底材200上形成一不透明層202，並且利用傳 統的微影蝕刻步驟，在不透明層2 0 2上方形成第一開口 2 0 4 以及第二開口 206，其中第一開口 2 04可以稱為非蝕刻相位 移開口，第二開口 2 0 6可以稱為蝕刻相位移開口。 接著’第二B圖是表示為了進行影像平衡步驟，將第 一光阻層210形成於不透明層202上方，並覆蓋住第一開口 204。在第二c圖，利用乾式姓刻（dry etching)的方式I虫 刻透明底材2 0 0，在透明底材2 0 0内，形成具有第一深度Figures 2A to 2C are schematic diagrams showing the steps of forming an etching phase shift opening using two etching steps. Similar to the first A picture, in the second A picture, an opaque layer 202 is formed on the transparent substrate 200, and a first lithographic etching step is used to form a first opening 2 0 4 above the opaque layer 2 0 2 and The second opening 206, wherein the first opening 204 may be referred to as a non-etched phase shift opening, and the second opening 206 may be referred to as an etched phase shift opening. Next, 'second B' shows that in order to perform the image balancing step, a first photoresist layer 210 is formed over the opaque layer 202 and covers the first opening 204. In the second figure c, the transparent substrate 2 0 is etched using dry etching method I, and the transparent substrate 2 0 is formed to have a first depth.

214的第三開口 212。同樣的，此第一深度2i4會在後續的 曝光光源照射步驟中，在第一開口 （非蝕刻相位移開口） 2 〇 4與第三開口（蝕刻相位移開口）2丨2之間產生丨8 〇度的 相位。Third opening 214 212. Similarly, this first depth 2i4 will be generated between the first opening (non-etching phase shift opening) 2 0 and the third opening (etching phase shift opening) 2 丨 2 in the subsequent exposure light source irradiation step 丨 8 〇degree phase.

第8頁 200528941_ 五、發明說明（5) 接著，第二D圖表示，移除第一光阻層21〇之後，對第 三開口 2 1 2進行等向性濕式触刻步驟，使得第三開口 21 2 的兩側向不透明層202下方蝕刻一寬度216，以及在透明底 材2 0 0内姓刻第·一咏度2 2 0 ’以形成一個所謂的底切 (undercut)結構218。 在第二D圖中的虛線區域是表示在第一次姓刻步驟中 ，敍刻透明底材200所形成的第三開口212，實線區域則 是表示利用第二次蝕刻步驟，蝕刻透明底材2〇〇以形成底 切結構218。當曝光光源照射具有第二深度220之底切結 構2 1 8以及第一開口 2 〇 4時，會產生為1 8 〇度的相位差。由 於在透明底材200内，具有一寬度216之底切結構218在曝 光光源照射之後，不會有散射現象的發生。第二E圖表示 當曝光光源照射第二D圖中的第一開口2〇4，以 218時，所產生的光源強度之示意圖。 —Page 8 200528941_ 5. Description of the invention (5) Next, the second D diagram shows that after the first photoresist layer 21 is removed, the isotropic wet-etching step is performed on the third opening 2 1 2 to make the third A width 216 is etched on both sides of the opening 21 2 below the opaque layer 202, and a first etch degree 2 2 0 ′ is engraved on the transparent substrate 200 to form a so-called undercut structure 218. The dashed area in the second D figure shows the third opening 212 formed by the transparent substrate 200 in the first surname engraving step, and the solid line area shows that the transparent substrate is etched by the second etching step. Material 200 to form an undercut structure 218. When the exposure light source irradiates the undercut structure 2 18 having the second depth 220 and the first opening 204, a phase difference of 180 degrees is generated. Since the undercut structure 218 having a width 216 in the transparent substrate 200 is irradiated by the exposure light source, no scattering phenomenon occurs. The second diagram E shows a schematic diagram of the intensity of the light source generated when the exposure light source irradiates the first opening 204 in the second diagram D to 218. —

底切結構218與第一開口（非蝕刻相位移開口）2〇4經 =^源照射之後，產生相同振幅的光強度，使得圖案轉 】：片T丄其圖案的位置有所誤差。但是，此方法的缺 原照射第一開0 204之後所產生的振幅強 光夕^ j圖中的非蝕刻相位移開口 1 04經照射曝光 因此，1 a—E圖中由虛線所表示的振幅強度）較小。 然可以二县的，析度降低。所以，轉移到晶片上的圖案J 谷、品分出來，但是，圖案的解析度則是降低After the undercut structure 218 and the first opening (non-etching phase shift opening) 204 are irradiated with the light source, the light intensity of the same amplitude is generated, so that the pattern is turned.]: The position of the pattern of the sheet T is incorrect. However, this method lacks the amplitude of the amplitude light generated after the first opening of 0 204. The non-etching phase shift opening in the figure is exposed by irradiation. Therefore, the amplitudes indicated by the dashed lines in 1 a-E diagrams Intensity) is small. Of course, the resolution can be reduced in the two counties. Therefore, the pattern J valley and quality transferred to the wafer are separated, but the resolution of the pattern is reduced.

第9頁 200528941Page 9 200528941

力彳 圖所示，在第：^、二像平衡的方“ 一 "_从夂第二』 上方，並利用；二V:透明層3 02 =在透明底材3°° 第一開口 304，步驟’姓刻不透:層302，以形成 ，如第三B圖戶斤亍，/ —開口 306於不透明層302内。接著 31〇，然後，執于不透明層3〇2 ^形成第一光阻層 第-溝渠開口312，=刻步驟，於^明底材3〇0内形成 渠開口312為非餘列二及第二溝渠開口3上4。其中’第-溝 度（第一深度目同開口312與第二溝渠開口314的深 # 一接著，參考第三D圖，在移除第一光阻層31 〇之後，將 第一光阻層320覆蓋在部份的不透明層302上方，以及第_ 開口 304的上方，並曝露出第二溝渠開口312。 接著，參考第三E圖，對透明底材300進行第二次蝕 刻步驟，以形成具有第二深度318的第三溝渠開口 322。同 樣地’在第一溝渠開口 312與第三溝渠開口 322之間的深 度31 8 ’經曝光光源照射時，可以產生丨8 〇度的相位。但是 ’由於第二溝渠開口 3 2 2的側壁會有散射現象的問題，而 導致光源強度不足的問題發生。因此，如第三F圖所示， 在第二溝渠開口 3 2 2的側邊’以及底部以濕式餘刻的方式 ’在透明底材300内形成具有一第三深度324之底切結構As shown in the force diagram, above the first and second image balanced squares "a" and "from the second", and used; two V: transparent layer 3 02 = 3 °° transparent substrate first opening 304 Step 'The last name is opaque: layer 302 to form, as shown in Figure 3B, the opening 306 is in the opaque layer 302. Then 31 °, and then adhere to the opaque layer 302 to form the first The first trench opening 312 of the photoresist layer is a engraving step, and the trench opening 312 is formed in the substrate 300 as a non-residual row 2 and the second trench opening 3 is 4. The 'first-ditch (first depth) The depth of the opening 312 and the second trench opening 314 is as follows. Referring to FIG. 3D, after the first photoresist layer 31 is removed, the first photoresist layer 320 is covered over a part of the opaque layer 302. And above the _th opening 304, and the second trench opening 312 is exposed. Next, referring to FIG. 3E, a second etching step is performed on the transparent substrate 300 to form a third trench opening having a second depth 318. 322. Similarly, 'the depth 31 8' between the first trench opening 312 and the third trench opening 322 may be irradiated by the exposure light source, A phase of 80 degrees is generated. However, the problem of insufficient light source intensity occurs due to the scattering phenomenon of the side wall of the second trench opening 3 2 2. Therefore, as shown in the third F diagram, in the second trench An undercut structure having a third depth 324 is formed in the transparent substrate 300 by the sides of the opening 3 2 2 and the bottom in a wet-type manner.

200528941 五、發明說明（7) ^~ 3 2 6 (實線區域）。此底切結構3 2 6部份位於不透明層3 〇 2的200528941 V. Description of the invention (7) ^ ~ 3 2 6 (solid line area). The undercut structure 3 2 6 is located in the opaque layer 3 02

下方，利用底切結構326可以解決散射現象的問題，但H ，由於進行底切步驟時，底切結構324的寬度320不容易$ 制，若是底切結構326的寬度320過寬，則位於透明底材i 300上方的不透明層302會因為位於透明底材3〇〇的寬度不 足，而產生剝離（peel ing)的現象，使得整個半導體製程 不能繼續進行下去。 衣王 三、【發明内容】 為了解決習知技術中，由於過度的底切，造成透明底 材上方不透明層所產生的剝離問題，以及解決曝光之後圖 案解析度不足的問題，本發明提供一種結合底切結構 (undercut)以及偏斜圖案（bias)的方式，以改善相位移光 罩之影像平衡的問題。 本發明的目的，在於利用兩次光罩寫入的方式，在移 蝕刻相位移開口的部份’以底切的方<，使得蝕刻相位移 開口的兩側以及底部的部份延伸至透明底材内，在曝光光 源照射的時候’蝕刻相位移開口的光源強度與非蝕刻相位 移開口的光源強度相等。 根據以上所述之目的，本發明提供利用兩次光罩寫入 的方式’在透明底材内形成具有-深度之底切結構 (undercut structure)，當曝光光源照射該底切結構時’Below, the undercut structure 326 can solve the problem of scattering phenomenon, but H, because the width 320 of the undercut structure 324 is not easy to make when the undercut step is performed. If the width 320 of the undercut structure 326 is too wide, it is located transparent The opaque layer 302 above the substrate i 300 will cause peeling due to the insufficient width of the transparent substrate 300, which makes the entire semiconductor process unable to continue. Yi Wangsan [Summary of the Invention] In order to solve the problem of peeling caused by the opaque layer above the transparent substrate due to excessive undercut in the conventional technology, and to solve the problem of insufficient resolution of the pattern after exposure, the present invention provides a combination Undercut structures and bias patterns are used to improve the image balance of the phase shift mask. The purpose of the present invention is to use the method of two photomasks to make the portion of the etching phase shift opening 'in an undercut square < so that both sides of the etching phase shift opening and the bottom portion extend to be transparent. In the substrate, when the exposure light source is irradiated, the intensity of the light source of the etched phase shift opening is equal to the intensity of the light source of the non-etched phase shift opening. According to the above-mentioned object, the present invention provides a method of writing with two photomasks. 'Forming an undercut structure with a depth in a transparent substrate, when the exposure light source illuminates the undercut structure.'

第11頁 200528941 五、發明說明（8) 所產生的光強&，與非蝕刻相位移開口的光源強度相等。 因此，在圖案轉移到晶片時，；^合、生 解析度不佳。 不會造成®㈣偏移或者是 兩:光罩寫入的步驟包含提供一透明底材，在透明底 材上形成一不透明層。接菩，尤 、采 设/1/f 按者在不透明層上形成具有圖案 之而m’此圖案中的非蝕刻相位移區域之間的寬度放二 卢纩丨ΐ:移區域與鄰近的非蝕刻相位移區域之間的寬 ^雨目偏ί t不透明層之後，彳以得到非#刻相位移區 丄的不向兩側放大’❿鄰近於餘刻相位移區域 離縮小。a /、非蝕刻相位移區域上的不透明層之間的距 用俱ίί、’第一光阻層覆蓋在非蝕刻相位移區域上方，利 ，‘透明行濕式蝕刻，以蝕刻钱刻相位移區域 产相你软- 相對應於非蝕刻相位移區域具有1 8 〇 = 接著，在㈣相位移區域進行丄驟 相位移區域的寬度變t ’ a部份位於不透明層 則是盘非:虫4由曝光光源照射之後所產生的光源強度： J疋，、非蝕刻相位移區域所產生的光源強度相同。 四、【實施方式】 细描51明2 一些貫施例會詳細描述如下。然而，除了詳 ' ^ 本發明還可以廣泛地在其他的實施例施行，且 200528941 五、發明說明（9) 本發明的範圍不受限定，其以之後的專利範圍為準。 根據習知的技術可以得知，利用蝕刻透明底材產生非 ?刻2位移開π，以及蝕刻相位移開口，在曝光光源照射 時’曰因為散射現象造成餘刻相位移開口所產生的曝光強 f與非蝕刻相位移開口兩者不相#，使得圖案轉移至晶片 叶，造成相位（phase)以及圖案位置的誤差。因此，根 上述之缺點，本發明提出兩次光罩寫入的方法，使得轉移 至晶片上的圖案位置以及相位沒有任何誤差。 .根據光罩技術而言’對於具有非f小的騎尺寸（cDs 當C二:」，enSi〇n)的圖案’例如電晶體的閘極，最 shlft mask)，x可以稱為Levens〇n 析度，以二?式相位移光罩的特點是對於圖案的解 用ΐ右柱社t耘見今度的具有明顯的改善效果，但是不適 〃有特殊邊角圖案或是孤立圖案。 之後當案：t轉移層與未經相轉移層光束 等）之相*間產生疋（或“、5疋、Η·. 場的振幅強产立之白？：^全破壞性干涉，使得兩個電 位差為」53里ffV:兩個電場振幅向量相對相 度，亦李干而本：不相位差為半波長，相位移角度差180 、不兩先束振進（propagate)時，位置相差半波 第13頁 200528941 五、發明說明（10) 長。當兩光束之相位差為π (半波長）時，或者為半波 奇數倍時，即形成完全破壞性干涉。 第四Α圖至第四Ε圖是用來說明本發明根據間隔式相位 移光罩之原理，利用兩次光罩形成具有底切結構以產生 衡影像之步驟示意圖。參考第四A圖及第圖，提供一 明底材10，此透明底材10為石英。接著，在透明底材1〇上 形成一不透明層（或稱為圖案層pattern layer)12， 透明層12的主要材料為鉻（chr〇me)。接著，在不透明芦 上方形成具有圖案之第一光阻層丨丨。 曰 在本發明中，第一光阻層丨丨上的圖案經過偏斜 :s:):案步驟，將圖案中的第一開口區域11A偏斜 得該第一開口區域11A的寬度擴大；對於圖 二:區域m偏斜一寬度D2，使得該第二開 第二二®的見度縮小，*中偏斜的寬度大約為400埃。 戶牛驟二:11上的圖案經過偏斜圖案步驟之後，可以在後 =傳統的像圖案。然後’如第㈣圖所示， 相二二中第一開口14可以定義為非"刻 口 16可以定義為斜方 phase shlft 〇pening)，第二開 opening)。 ” 』相位移開口（ e tched phase sh i f tPage 11 200528941 V. Description of the invention (8) The light intensity & produced is equal to the light source intensity of the non-etching phase shift opening. Therefore, when the pattern is transferred to the wafer, the resolution is poor. Does not cause ®㈣ shift or two: The mask writing step includes providing a transparent substrate to form an opaque layer on the transparent substrate. Then, you can use / 1 / f to form a pattern on the opaque layer, and m 'the width between the non-etched phase shift regions in this pattern. Put two Lu 纩 ΐ: the shift region and the adjacent non- After etching the wide opaque layer between the phase shift regions, the non- # etched phase shift region is not enlarged toward both sides, so that it is adjacent to the remaining phase shift region. a /, the distance between the opaque layers on the non-etched phase shift area is used, 'the first photoresist layer is covered over the non-etched phase shift area, Lee,' transparent line wet etching to etch the phase shift The region phase is soft-corresponding to the non-etched phase shift region with 1 8 〇 = Then, the width of the phase shift region in the phase shift region is changed to t 'a part is located in the opaque layer is Panfei: Worm 4 The intensity of the light source generated by the exposure light source: J 疋, the intensity of the light source generated in the non-etched phase shift region is the same. Fourth, [implementation] Detailed description 51 Ming 2 Some implementation examples will be described in detail below. However, in addition to the details, the present invention can be widely implemented in other embodiments, and 200528941 V. Description of the invention (9) The scope of the present invention is not limited, and the scope of the following patents shall prevail. According to the conventional technology, it can be known that the use of etching a transparent substrate to generate a non-etched 2 shift opening π and an etched phase shift opening, when the exposure light source is irradiated, said that the strong exposure caused by the phase shift opening caused by the scattering phenomenon due to the scattering phenomenon. f is not in phase with the non-etched phase shift opening, which causes the pattern to be transferred to the wafer leaf, causing errors in phase and pattern position. Therefore, in view of the above disadvantages, the present invention proposes a method of two mask writing so that there is no error in the position and phase of the pattern transferred to the wafer. According to the mask technology, 'for a pattern with a small non-f ride size (cDs when C2: ", enSi0n)' (such as the gate of a transistor, the most shlft mask), x can be called Levens〇n The resolution of the two-phase phase shift mask is that for the resolution of the pattern, the right column has a significant improvement effect, but it is not suitable for the special corner pattern or isolated pattern. Afterwards: 疋 (or ", 5 疋, Η · .. The amplitude of the field produces a strong white field between the t-transfer layer and the beam without the phase-transfer layer, etc.?": ^ Totally destructive interference, making two The potential difference is 53 ffV: the relative phase of the two electric field amplitude vectors, which is also Li Qian: the phase difference is half the wavelength, the phase shift angle is 180 degrees, and the position difference is half when the two beams are propagate. Page 13 200528941 V. Description of the invention (10) Long. When the phase difference between the two beams is π (half wavelength), or an odd multiple of a half wave, a completely destructive interference is formed. The four E diagrams are used to explain the steps of the present invention based on the principle of the spaced phase shift mask, using the two masks to form an undercut structure to produce a balanced image. Refer to the fourth A and the diagram to provide a clear background Material 10, the transparent substrate 10 is quartz. Next, an opaque layer (or a pattern layer) 12 is formed on the transparent substrate 10, and the main material of the transparent layer 12 is chromium. A first photoresist layer with a pattern is formed over the opaque ash. In the present invention, the pattern on the first photoresist layer 丨 is subjected to a skew: s :): case step, the first opening region 11A in the pattern is skewed so that the width of the first opening region 11A is enlarged; 2: The area m is deflected by a width D2, so that the visibility of the second opening 22 is reduced, and the width of the middle deviation is about 400 Angstroms. After the deflection pattern step on the pattern on Hou Niu Step 2:11, it can be followed by the traditional image pattern. Then, as shown in the second figure, the first opening 14 in phase two or two can be defined as a non- " notch 16 can be defined as an oblique phase shlft 〇pening), and the second opening). ”』 Phase shift opening (e tched phase sh i f t

200528941 五、發明說明（11) ' — ' - 在本發明之較佳實施例中，與習知技術第一A圖，位 於透明底材100上方之第一開口 1〇4，以及第二開口 ι〇β來 比較’相鄰的不透明層1 〇 2之間的第一開口 1 4比第一 a圖中 的第一開口 1 04之間的寬度大。而第二開口丨6的寬度則是 比習知技術第一A圖中的第二開口丨〇6的寬度小。在此，虛 線1的部份是表示第一開口 1 4所增加的寬度，虛線2的部份 是表示第二開口 1 6所減少的寬度。藉由第一開口丨4之間^ 寬度放大’以及第二開口 1 6的寬度縮小如第四B圖所示， 來改變蝕刻透明底材1 〇的寬度，使得在後續的曝光照射以 及蝕刻步驟中，所產生的底切結構不會有過度底切，而造 成不透明層12的剝離（peei ing)現象。200528941 V. Description of the invention (11) '—'-In the preferred embodiment of the present invention, the first figure A of the conventional technology, the first opening 104 and the second opening located above the transparent substrate 100 〇β to compare the width of the first opening 14 between the adjacent opaque layers 1 0 2 is larger than the width between the first openings 104 in the first a figure. The width of the second opening 6 is smaller than the width of the second opening 6 in the first A diagram of the conventional technology. Here, the part of the dotted line 1 indicates the increased width of the first opening 14 and the part of the dotted line 2 indicates the reduced width of the second opening 16. The width of the etched transparent substrate 10 is changed by increasing the width of the first opening 4 and the width of the second opening 16 and reducing the width of the second opening 16 as shown in FIG. 4B, so that in the subsequent exposure and irradiation and etching steps In the process, the undercut structure generated will not have excessive undercuts, which will cause peeling of the opaque layer 12.

，本發明中所使用的曝光光源（exp〇sure 可以疋波長為248奈米（nm)的KrF準分子雷射，或者是波長 為193奈米的ArF準分子雷射。m常使用波長248奈米的μ f 雷射是使用在〇.13微米製程，而波長193奈米的ArF 準为子雷射則可以用在尺寸小於〇. 13微米的製程中。 =來’參考第四c圖，在第一光阻層“料之後， 二〇 上$，以及不透明層12的上方形成第二光 :f20:參考第四D圖，執行-第-蝕刻步驟，例如乾式 产二之：由第二，口16在透明底材10内，形成具有第-深 ί-;=Γ;Λ中，第三開口22於透明底材10内的 弟 又24與第一開口14之間的相位差為180度。The exposure light source used in the present invention (exposure can be KrF excimer laser with a wavelength of 248 nanometers (nm), or ArF excimer laser with a wavelength of 193 nanometers. M often uses a wavelength of 248 nanometers The μ f laser of meters is used in the process of 0.13 micrometers, and the ArF quasi-sub-laser with a wavelength of 193 nanometers can be used in processes with a size of less than 0.13 micrometers. = 来 'Refer to the fourth c figure, After the first photoresist layer is formed, a second light is formed on top of the opaque layer 12 and the second light is formed on the opaque layer 12: f20: refer to the fourth D diagram, and perform a -first-etching step, such as dry production. The mouth 16 is formed in the transparent substrate 10 to have a -deep; = Γ; Λ, the phase difference between the third opening 22 in the transparent substrate 10 and the first opening 14 is 180. degree.

200528941200528941

一然後如第四E圖所示，在移除第二光阻層2〇之後， 第三開口 22内進行一第二蝕刻步驟，例如等向性渴蝕 刻，以執行底切（undercut)步驟，使得第三開口22的 =透明底材1〇内移除一寬度30 ’而底層則是移 ： 透明底材10，以形成第二深度28，而形成_底切結構“ (實線圍成的區域），其中，側壁所移除的寬度3〇大約為As shown in FIG. 4E, after the second photoresist layer 20 is removed, a second etching step, such as isotropic thirst etching, is performed in the third opening 22 to perform an undercut step. Make the third opening 22 = transparent substrate 10 remove a width of 30 'and the bottom layer is moved: transparent substrate 10 to form a second depth 28, and _ undercut structure "(enclosed by a solid line Area), where the width 3 of the side wall removed is approximately

TJV 士而具有深度28之底切結構26。由於在形成第四八圖 的^構蚪，已經將第一開口14的寬度放大（即兩個相鄰的 不透明層12之間的距離放大）’使得在透明底材1〇内的底 切結構26，不會有過度底切，而造成不透明層_寬度不 足會有剝離的現象發生。另外，同樣地’在進行曝光照射 時，由於底切結構26不會有散射現象發生，因此，當曝光 光源照射第-開口 14以及底切結構26時，所產生的曝光光 源強度相等，且具有深度28之底切結構26會產生18〇度相 位使得圖案轉移到晶片上時，其相位以及圖案的位置不 會有誤差產生，因此可以得到有良好解析度的圖案。 ^以上所述僅為本發明之較佳實施例而已，並非用以限TJV has an undercut structure 26 with a depth of 28. As the structure of Figure 48 is formed, the width of the first opening 14 has been enlarged (ie, the distance between two adjacent opaque layers 12 has been enlarged) so that the undercut structure in the transparent substrate 10 26. There will not be excessive undercuts, which will cause peeling when the width of the opaque layer is insufficient. In addition, similarly, during the exposure irradiation, since the undercut structure 26 does not cause a scattering phenomenon, when the exposure light source irradiates the first opening 14 and the undercut structure 26, the intensity of the exposure light source generated is equal and The undercut structure 26 at a depth of 28 will generate a 180 degree phase so that when the pattern is transferred to the wafer, there will be no error in the phase and the position of the pattern, so a pattern with good resolution can be obtained. ^ The above descriptions are merely preferred embodiments of the present invention, and are not intended to limit them.

=本七明之申凊專利範圍；凡其它未脫離本發明所揭示之 ^神下所70成之等效改變或修飾，均應包含在下述之申請 專利範圍内。= The scope of patent claims of this Qiming; all other equivalent changes or modifications that do not depart from the ^ God disclosed in the present invention shall be included in the scope of the patent application described below.

第16頁 200528941Page 16 200528941

五、【圖式簡單說明】 第一 A圖至 利用溼 移開口 m w μ 士』 C圖係根據傳統光學微影技術， 式名生刻的方式’產味止私tir 王曝光強度不相同的非蝕刻相位 ，以及蝕刻相位移開丰 W同口之步驟示意圖； 第一D圖係根據傳統光 射第一 C圖之結構所產生的 學微影技術，經由曝光光源照 不相等之光強度示意圖； 第二A圖至第二D 次姓刻的方式，產生 以及蝕刻相位移開口 不意圖，V. [Schematic description] The first A picture to the use of wet shift opening mw μ shi ”C picture is based on the traditional optical lithography technology, the famous method of producing and engraving 'produce taste private tir King exposure intensity is not the same The schematic diagram of the etching phase and the phase shift of the etching phase. The first D picture is a schematic diagram of the lithography technology generated by the traditional light shot of the first C picture structure, and the unequal light intensity is illuminated through the exposure light source; The manners of the second A to the second D inscriptions are not intended to generate and etch the phase shift openings,

圖係根據傳統光學微影技術，利用兩 曝光強度相同的非蝕刻相位移開口， ’但會造成不透明層剝離現象之步驟 “货第η二^圖係根據傳統光學微影技術，利用曝光光源照 射第'一 D圖之結構所彦+ & |& 再叮座生的先源強度不足之示意圖； :三Α圖至第係根據傳統光學微影技術，利用兩 =步，，以及產生底切結構的方式，以產生平衡影像 步驟示意圖；以及The picture is based on the traditional optical lithography technology, using two non-etching phase shift openings with the same exposure intensity, but the step that will cause the phenomenon of peeling of the opaque layer "Product No. η2" is based on the traditional optical lithography technology, using an exposure light source Schematic diagram of the structure of the first 'D' + + & | & The schematic diagram of the lack of the intensities of the original source of the second generation; Figures A through D are based on the traditional optical lithography technology, using two = steps, and generating the bottom Cut the structure to produce a balanced image; and

明所揭露之技術，利用 ’產生曝光光源強度相 位移開口之步驟示意 第四A圖至第四E圖係根據本發 偏斜圖案以及產生底切結構的方式 同之非蝕刻相位移開口以及蝕刻相 圖。The technology disclosed in the Ming Dynasty uses the steps of “generating the phase shift opening of the exposure light source” to illustrate the fourth A to fourth E images. The non-etching phase shift opening and etching are the same according to the skew pattern of the present invention and the way of generating the undercut structure. Phase Diagrams.

200528941200528941

圖式簡單說明 主要部分之代表符號： 1 虛線 2 虛線 10 透明底材 11 第一光阻層 12 不透明層 14 第一開口 16 第二開口 20 第二光阻層 22 第三開口 24 深度 26 底切結構 28 深度 30 寬度 100 透明底材 102 不透明層 104 第一開口 106 第二開口 110 光阻層 112 第三開口 114 深度 200 透明底材 202 不透明層 200528941The diagram briefly shows the representative symbols of the main parts: 1 dotted line 2 dotted line 10 transparent substrate 11 first photoresist layer 12 opaque layer 14 first opening 16 second opening 20 second photoresist layer 22 third opening 24 depth 26 undercut Structure 28 depth 30 width 100 transparent substrate 102 opaque layer 104 first opening 106 second opening 110 photoresist layer 112 third opening 114 depth 200 transparent substrate 202 opaque layer 200528941

圖式簡單說明 204 第一開口 2 0 6 第二開口 2 1 0第一光阻層 2 1 2 第三開口 2 1 4 第一深度 216 寬度 2 1 8 底切結構 2 2 0 第二深度Brief description of the drawing 204 First opening 2 0 6 Second opening 2 1 0 First photoresist layer 2 1 2 Third opening 2 1 4 First depth 216 Width 2 1 8 Undercut structure 2 2 0 Second depth

3 0 0 透明底材 3 0 2 不透明層 304 第一開口 3 0 6 第二開口 310第一光阻層3 0 0 transparent substrate 3 0 2 opaque layer 304 first opening 3 0 6 second opening 310 first photoresist layer

3 1 2第一溝渠開口 3 1 4第二溝渠開口 3 1 6 第一深度 3 1 8 第二深度 320 第二光阻層 322第三溝渠開口 324 第三深度 326 底切結構3 1 2 First trench opening 3 1 4 Second trench opening 3 1 6 First depth 3 1 8 Second depth 320 Second photoresist layer 322 Third trench opening 324 Third depth 326 Undercut structure

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Claims (1)

200528941 六、申請專利範圍 一種利用偏斜圖索 的方法，包含： '成具有平衡影像之相位移光罩 提供一透明底材； 形成一不透明層於 執行-偏斜圖案步；”上方，· 或，以及-第二開口 先=上之具有-第-開口 域以及該第二開口區域偏斜=;案’使得該第—開口區 形成具有該偏斜圖=見度， 蝕刻該不透明層以开；J 5亥J阻層於該不透明層上方； 該不透明層内；以及v成一第一開口以及一第二開口於 移除該光阻層。 有影像平項所述之利用偏斜圖案形成具 料為石英。 罩的方法，其中上述透明底材的材 有4·::請f利範圍第1項所述之利用偏斜圖案形成具 位移光罩的方法，其中上述不透明層的材 v 4 ·如申請專利範圍第1項所述之利用偏斜圖案形成具 衫像平衡之相位移光罩的方法，其中上述寬度約為4 〇 〇 埃。 第20貢 2005289£[ 六、令請專利範圍 有影像平衡之相位H J1 的項方所述之:1二偏斜圖案形成具 該第一開口區域來，，八中經由該偏斜步驟之 縮小。 見度擴大且該第二開口區域之—寬度 有影像平衡之：：：：J1項所述之利用偏斜圖案形成具 步驟之後，利用—=的方法，更包含在移除該光阻層 構於該透明底材内以形成具有-深度之-底切結 ，使得該第—開 ^于5亥深度 '經由該曝光光源照射之後 與该底切結構產生1 8 0度相位。 的方法，包含用偏斜圖案形成具有平衡影像之相位移先罩 提供一透明底材； ^一不透明層於該透明底材上方； 開口區=步驟於-第一光阻層上之具有-第- 口區域以及#笛第二開口區域之一圖案，使得該第一開 :、及汶第一開口區域偏斜一寬度； 方七成具有4偏斜圖案之該第一光阻層於該不透明層上 =刻該不透明層以形成一第一開口以及一 邊不透明層内； 於 移除該第一光阻層； 形成一第二光阻層覆蓋在該第一開口，以及該不透明 第21頁 200528941200528941 VI. Scope of patent application A method using skewed maps, including: 'provide a transparent substrate with a phase shift mask with a balanced image; form an opaque layer at the execution-skew pattern step; "above, · or , And-the second opening first = the upper-opening region and the second opening region are skewed; the case 'makes the first opening region having the skew pattern = visibility, and the opaque layer is etched to open A J resist layer on top of the opaque layer; inside the opaque layer; and v forming a first opening and a second opening to remove the photoresist layer. There is an oblique pattern forming device as described in the image flat item The method of the mask, wherein the material of the transparent substrate is 4 :: The method for forming a displacement mask using a skew pattern as described in item 1 of the above range, wherein the material of the opaque layer is v 4 The method for forming a phase-shifting photomask with a balanced image using a skewed pattern as described in item 1 of the scope of the patent application, wherein the above width is about 400 angstroms. 20th tribute 2005289 £ Image level The phase of the phase H J1 is described as follows: 1 Two skew patterns are formed with the first opening area, and the eighth middle is reduced through the skew step. The visibility is expanded and the second opening area has an image of the width Balance: ::: After the step of using the oblique pattern formation described in the item J1, the method of using-= is further included to remove the photoresist layer into the transparent substrate to form a bottom with a depth of- Cut the knot, so that the first-opened at a depth of 50 ′ irradiates through the exposure light source to produce a 180 degree phase with the undercut structure. The method includes forming a phase shift with a balanced image using a skew pattern to provide a first mask A transparent substrate; ^ an opaque layer over the transparent substrate; an opening area = a step on the first photoresist layer having a pattern of a -th-opening area and a #fist second opening area, so that the first On: the first opening area of Hewen is skewed by a width; Fang Qicheng has the first photoresist layer with a 4 skew pattern on the opaque layer = engraving the opaque layer to form a first opening and one side of the opaque layer Removing the first photoresist layer; A second photoresist layer to cover the first opening, and opaque Page 21200528941 六、申請專利範圍 層上方； 進4亍 ' 一第—名生？丨丨半臣取 材，以移除部份的該=底^由該第二開口敍刻該透明底 一第三開口； 月底材，以形成具有一第一深度之 移除該第二光阻層； 執行一第二蝕刻步驟經由 第二深度之一底切处Μ 第二開口，以形成具有一 較第-深度深遠透明底材内…該第二深度 照射一曝光光源於該第一 影一圖案於一晶片上。 4 ，以及該底切結構以投 8.如申請專利範圍 衡的方法，豆中卜、t 4 ηη /江之相位移先罩之影像平 八甲上述透明底材的材料為石英。 卞 9+如申請專利範圍第7項所述之相位 衡的方法，豆φ μ、+、τ ☆ U平 < 衫像平 ，、T上述不透明層的材料為鉻。 1 〇 ·如申請專利範圍第7所述之相位移 衡的方法，豆φ μ、+、姑 ,^ ^ ^ , 平 < 衫像平 /、τ上逃第一餘刻步·驟為乾式姓刻。 @ΛΛΠ·如申請專利範圍第7項所述之相位移光罩之影傻承 两的古、、i 4+ » , , ’了^丨本干 ， 法，八中上述第一深度在經由該曝光光源照射之 吏得該第一開口與該第三開口產生1 80度相位。 便Sixth, the scope of patent application is above the level;丨 丨 Banchen takes material to remove part of the = bottom ^ The transparent bottom and the third opening are engraved from the second opening; moon substrate to form a second photoresist layer with a first depth removed Performing a second etching step through an undercut at a second depth and a second opening to form a transparent substrate having a deeper depth than the first depth ... the second depth illuminates an exposure light source onto the first shadow-one pattern On a wafer. 4, and the undercut structure is cast. 8. According to the method of applying for a patent balance, the image of Dou Zhongbu, t 4 ηη / river phase shift first mask is flat. The material of the above transparent substrate is quartz.卞 9+ The method of phase balance as described in item 7 of the scope of the patent application, beans φ μ, +, τ ☆ U flat < shirt like flat, T, the material of the opaque layer is chromium. 1 〇 As described in the method of phase shift of the patent application No. 7, the phase shift balance method, beans φ μ, +, Gu, ^ ^ ^, flat < shirt like flat /, τ escape the first remaining step. Last name carved. @ ΛΛΠ · As described in item 7 of the scope of the patent application, the shadow of the phase shift mask is the same as the old one, i 4+ »,," 了 ^ 丨 本 干, 法, The exposure of the exposure light source results in that the first opening and the third opening generate a 180 degree phase. To 200528941 六、申請專利範圍200528941 6. Scope of Patent Application 1 2 ·如申請專利範圍第7 衡的方法，其中上述第 項所述之相位移光罩之影像平 刻步驟為等向性濕式蝕刻。 ^ 1 3·、如申請專利範圍第7項所述之相位移光罩之影像平 衡的方法，其中上述曝光光源為波長248奈米之準分子 1 4·如申請專利範圍第7項所述之相位移光罩之影像平 衡的方法，其中上述曝光光源為波長193奈米之Ar 雷射。 千刀卞 1 5· —種相位移光罩之影像平衡的方法，該方法包含 提供一透明底材； 形成一不透明層於該透明底材上； 執行一偏斜圖案步驟於一第一光阻層之具有一第一 口區域，以及一第二開口區域之一圖案，以放大該第一二 口區域以及縮小該第二開口區域； 於該不透明層上； 形成一第一開口以及 形成具有該圖案之該第一光阻層 執行一蝕刻步驟於該不透明層以 第二開口於該不透明層内； 移除該第一光阻層 覆蓋在該第一開口以及該不透明 形成一第二光阻層 層上方； 執行一乾式蝕刻步驟， 經由該第二開口蝕刻該透明底 2005289411 2 · The method of claim 7 in the scope of the patent application, wherein the image engraving step of the phase shift mask described in the above item is isotropic wet etching. ^ 1 3. The method of image balance of a phase shift mask as described in item 7 of the scope of patent application, wherein the exposure light source is an excimer with a wavelength of 248 nm 1 4 · As described in item 7 of the scope of patent application A method for image balance of a phase shift mask, wherein the exposure light source is an Ar laser with a wavelength of 193 nm. Thousand Knifes 1 ·· A method for image balance of a phase shift mask, the method includes providing a transparent substrate; forming an opaque layer on the transparent substrate; performing a skew pattern step on a first photoresist The layer has a first opening area and a pattern of a second opening area to enlarge the first two opening areas and reduce the second opening area; on the opaque layer; forming a first opening; The patterned first photoresist layer performs an etching step on the opaque layer with a second opening in the opaque layer; removing the first photoresist layer to cover the first opening and the opacity to form a second photoresist layer Over the layer; performing a dry etching step to etch the transparent bottom through the second opening 200528941 申請專利範圍 材i Ϊ形成具有—第―深m三開°於該透明底材肉 八中邊第一深度在經由一曝光光源照射〜内 一開口與該第三開口產生180度相位； 使诗該第 移除第二光阻層； S亥繁—0 9 ^二開口内進行一底切步驟，以形成具有一㈣ 度深广a構於該透明底材内，Λ中該第二深度較；：; 曰曰 片上知射該第一開口以及該底切結構以投影一圖案於 1 6 ·如申 平衡的方法 請專利範圍第1 5項所述之相位移光罩之影像 其中上述透明底材的材料為一石英。〜 1 7 ·如申 平衡的方法 請專利範圍第1 5項所述之相位移光罩之影像 ’其中上述不透明層的材料為鉻。 平衡S·如申請專利範圍第1 5項所述之相位移光罩之影像 、、方去’其中上述底切步驟為一等向性濕式蝕刻。 平衡1 9·如申請專利範圍第1 5項所述之相位移光罩之影像 子t f方法’其中上述曝光光源為波長248奈米之KrF準分 2 〇 •如申請專利範圍第1 5項所述之相位移光罩之影像The scope of the patent application material i Ϊ is formed to have the first depth of the third depth of the transparent substrate, the first depth of which is irradiated through an exposure light source ~ an inner opening has a 180-degree phase with the third opening; The second photoresist layer is removed; an undercutting step is performed in the openings of 0-9 ^^ to form a transparent structure having a depth of a wide structure in the transparent substrate, and the second depth in Λ is relatively large; ：; Said that the first opening and the undercut structure are projected on the film to project a pattern on 16 · If the method of balancing is applied, please call the image of the phase shift mask described in item 15 of the patent scope among the transparent substrates The material is a quartz. ~ 1 7 · As described in the balance method, please ask for the image of the phase shift mask described in item 15 of the patent scope ’wherein the material of the opaque layer is chromium. Equilibrium S. The image of the phase shift mask described in item 15 of the scope of the patent application, and the squares are used, wherein the undercut step is an isotropic wet etching. Balance 19 • The method of imaging sub-ff of a phase shift mask as described in item 15 of the scope of patent application 'wherein the above exposure light source is a KrF quasi-score 2 of wavelength 248 nm. Image of phase shift mask 第24頁 200528941 六、申請專利範圍 平衡的方法，其中上述曝光光源為波長193奈米之A rF準分 子雷射。 liB 第25頁Page 24 200528941 6. Balanced patent application method, in which the exposure light source is an A rF excimer laser with a wavelength of 193 nm. liB Page 25