五、發明說明（1) 本發明係有關於一種衰減式相位移光罩之製造方法， 特別有關於一種高透光率衰減式相位移光罩之製造方法， 利用既有之低透光率光罩底材（blank)及一特殊之化學溶 液製造出一具有較高透光率之衰減式相位移光罩。 在半導艘製程中，晶片進行表面光阻的曝光所需要的 工具除光源外’還有用來提供線路圖形以便執行圖形轉移 的光罩。目前隨著積體電路體積不斷地縮小，因此對光軍 的光學性能之要求也愈來愈高。於是許許多多具有不同優 點與，學特性之光罩不斷地被提出，其中有一種為人所熟 知之衰減式相位移光罩（Attenuated Phase ShiftV. Description of the invention (1) The present invention relates to a method for manufacturing an attenuated phase shift mask, and more particularly to a method for manufacturing a high-transmittance attenuated phase shift mask, using existing low-light-transmittance light The cover substrate (blank) and a special chemical solution make an attenuation phase shift photomask with higher light transmittance. In the semi-conductor process, the tools required for the exposure of the surface photoresist to the wafer are in addition to the light source 'and a photomask used to provide the pattern of the pattern to perform pattern transfer. At present, as the volume of integrated circuits continues to shrink, the optical performance requirements of the optical army have become higher and higher. As a result, many reticle with different advantages and learning characteristics have been proposed continuously. One of them is known as Attenuated Phase Shift Mask.
Mask)，其係藉由在圖形周圍產生相位差18〇度且大小經衰 減過之光，造成破壞性干涉而將超越圖形範圍之曝光量縮 小’使圖形更精確。 在衰減式相位移光罩之製造中，由於在鉻層與石英層 之間需要增加-會吸收部份光之半透光層，如透光度細 之〇Si ON，所以在製造衰減式相位移光罩時，會直接在市 =上購買現成之含有半透光層的光罩底材（Mank)做為材 由於化學耐受性的問題，目前市面上所能得到之光罩 底材中’其半透光層之透光率均為6%。 圖1人至111顯示了一傳統衰減式相位移光罩及其製作過 =。圖1A係此衰減式相位移光罩上之圖案，具有一黑暗區 lb、一半透光區13及一透光區U。 先，如圖1B，提供一光罩底材，具有一透光率1〇〇% 石央所構成之透光層12、一透光率6%之之M〇Si〇N所構成Mask), which reduces the amount of exposure beyond the range of the pattern by making light with a phase difference of 180 degrees around the pattern and attenuated light, reducing the amount of exposure beyond the range of the pattern to make the pattern more accurate. In the manufacture of the attenuation phase shift mask, a semi-transmissive layer that will absorb part of the light, such as SiON, which absorbs some light, needs to be added between the chromium layer and the quartz layer. When displacing a photomask, a ready-made photomask substrate (Mank) containing a translucent layer will be purchased directly on the market as a material. Due to the problem of chemical resistance, currently available photomask substrates on the market 'The transmissivity of its semi-transparent layer is 6%. Figures 1 to 111 show a conventional attenuation phase shift mask and its fabrication. FIG. 1A is a pattern on the attenuation phase shift mask, which has a dark region lb, a semi-transparent region 13 and a transparent region U. First, as shown in FIG. 1B, a mask substrate is provided, which has a light-transmitting layer 12 composed of a light transmittance of 100% Shi Yang, and a light-transmitting layer composed of 6% MoSiON.
第4頁 五、發明說明（2) 之半透光層14及一透光率〇%之Cr所構成之遮光層16，並在 此光罩底材之遮光層16上覆蓋一光阻層18。 如圓1C，對半透光區13及透光區11内之光阻層進行曝· 光’半透光區13内光阻層18之曝光深度較透光區11内光阻 層18之曝光深度短，且不及遮光層16。 如圖1D ’以二甲越.乙二醇（diethyl glycol dimethyl ether)及甲乙嗣（methyl ethyl ketone)之混合 液做為顯影劑進行顯影，使透光區内之遮光層16露出β 如圖1Ε ’以光阻層18為遮罩依序對遮光層丨6及半透光 層14進行蝕刻，使相對之透光層12露出。 一 如圖1F ’對光阻層18進行蝕刻，使半透光區13内之遮 光層1 6露出’此蚀刻步驟為以氧氣為蝕刻氣體之乾蝕刻。 如圖1G ’再以光阻層18為遮罩對遮光層16進行蝕刻， 使相對之半透光層14露出。 最後，如圖1H，藉由硫酸以及過氧化氫之混合溶液， ，其他適用之溶液將光阻層18剝除，即完成一傳統之衰減 式相位移光罩》 然而，透光率之增加可以使衰減式相位移光罩具有較 ，之聚焦深度（depth of f0cus)，尤其是在製作〇 2/^大 =之接觸窗時，6%之透光率所產生之聚焦深度是不足夠 :二因此，依上述傳統製程所製作出的衰減式相位移光罩 求。於是在美國專利第5614335號中便提 广b】：：*光層具有可變透光率之光罩底材 (bUnk)，可以製作出半透光層之透光率高於 五、發明說明（3) 相位移光罩。 同樣為了提高奋，法、 率，本發明亦提： = 移光罩之半透光層之透光 製造方法，係利用：：透光率之衰減式相位移光罩之 透光層=率之出：用r學溶液提高半 二：處理=過度钱刻，★將相位角提高，再用化學溶 =做處理’同時提高半透光層之透光率及完成相位角之補 之製造方；^本發明即提供一種高透光率衰減式相位移光罩 位L之衰威Λ用一化學溶液製造-具有高透光率τ及相 一透光層及/读、位移光罩其中衰減式相位移光罩具有 間變化率dT Β ί光層圖％，而化學溶液可產生一透光率時 :ΪΓ一間變化_，該方法包括以下步 低透ί率r;將透光層及半透光層圖形轉移至 而—且古同時對透光層圖案内之透光層進行過度蝕刻 光ί 位角？，及低透光率τ，之準衰減式相位移 iu::p+(T-T，）xdp/dT;將該準衰減式相位移光 容液中’分別使準衰減式相位移光罩之相位 月及透先率由Ρ，及Τ，修正為Ρ及Τ。 ★其中，該化學溶液為ΝΗ4〇Η : η2〇2 : M=1 : i : 5之SC1 :液，其透光率時間變化率dT及相位角時間變化率dp分別 為 0. 0 4 8 % / m i η 及 0. 4 3 2。/ m i η。 第6頁Page 4 V. Description of the invention (2) A semi-transparent layer 14 and a light-shielding layer 16 composed of 0% Cr, and a light-shielding layer 18 is covered on the light-shielding layer 16 of the mask substrate. . As circle 1C, the photoresist layer in the semi-transparent area 13 and the transparent area 11 is exposed. The exposure depth of the photoresist layer 18 in the semi-transparent area 13 is greater than that of the photoresist layer 18 in the transparent area 11 The depth is short and is not as good as the light shielding layer 16. As shown in Figure 1D, a mixed solution of diethyl glycol, diethyl glycol dimethyl ether and methyl ethyl ketone is used as a developer for development, so that the light-shielding layer 16 in the light-transmitting area is exposed to β as shown in Figure 1E 'Using the photoresist layer 18 as a mask, the light-shielding layer 6 and the semi-transparent layer 14 are sequentially etched to expose the opposite transparent layer 12. First, as shown in FIG. 1F, the photoresist layer 18 is etched to expose the light-shielding layer 16 in the translucent region 13. This etching step is dry etching using oxygen as an etching gas. As shown in FIG. 1G ′, the light-shielding layer 16 is etched with the photoresist layer 18 as a mask to expose the opposite semi-transparent layer 14. Finally, as shown in Fig. 1H, by using a mixed solution of sulfuric acid and hydrogen peroxide, and other suitable solutions, the photoresist layer 18 is stripped, and a traditional attenuation phase shift mask is completed. However, the increase in light transmittance can Make the attenuated phase shift reticle have a relatively deep depth of f0cus, especially when making a contact window of 0 / ^ large =, the focus depth produced by the 6% light transmittance is not enough: Therefore, the attenuation phase shift mask manufactured according to the above-mentioned traditional process is required. Therefore, in US Patent No. 5,614,335, b] :: * The photomask substrate (bUnk) with variable light transmittance can be used to make a translucent layer with a light transmittance higher than V. Invention Description (3) Phase shift mask. In order to improve the efficiency, method, and rate, the present invention also mentions: = The translucent manufacturing method of the semi-transparent layer of the light-transmitting mask, which uses :: The transmissive layer of the phase-shifting mask with the attenuation of the transmittance = the rate of Out: use R solution to improve half two: treatment = excessive money engraving, ★ increase the phase angle, and then use chemical solution = do 'treatment' while increasing the light transmittance of the semi-transparent layer and completing the phase angle supplement; ^ The present invention provides a high transmittance decay phase shift mask position L, which is made of a chemical solution-has a high light transmittance τ and a phase-transmitting layer and / read, displacement mask in which the attenuation type The phase shift photomask has an interlayer change rate dT Β ί photo layer%, and the chemical solution can produce a light transmittance: ΪΓ a change in _, the method includes the following steps low transmittance r; The pattern of the light-transmitting layer is transferred to—and at the same time, the angle of the light-transmitting layer in the pattern of the light-transmitting layer is over-etched. , And low transmittance τ, quasi-attenuation phase shift iu :: p + (TT,) xdp / dT; the quasi-attenuation phase-shifting photocapacitor liquid 'makes the phase month of the quasi-attenuation phase-shifting mask, respectively The penetration rate is revised from P, and T to P and T. ★ Among which, the chemical solution is ΝΗ4〇Η: η2〇2: M = 1: i: 5 of SC1: liquid, the transmittance time change rate dT and the phase angle time change rate dp are 0.04 8%, respectively. / mi η and 0.4 2. / m i η. Page 6
因此，藉由本發明之高透光率衰 造方法Tiit播珀一 位移光罩之絮 :万+ τ以使用-般市面上<光罩底材 ：：製 透光率高於6%之衰減式相位移光罩，且不 透光層 為讓本發明之上述目的、特徵及優相位角。 卜又特舉較佳實施例，並配合所 * 下。 ^町鬮八作詳細說明如 圖式簡單說明 圖1A〜1H顯示了 程。 一傳統衰減式相位移光罩之製造過 圖2A〜2H顯示了本發明一 位移光罩之製造過程。 符號說明 11〜透光區； 13~半透光區； 1 5〜黑暗區； 12、22〜透光層； 14、24〜半透光層； 16、26~遮光層； 18、28〜光阻層。 實施例 實施例之高透光率衰減式相 Γ 本實施例之高透光率衰減式相位移光罩之圖案與圖以 相同，具有一黑暗區15、一半透光區13及一透光區η。此 外’本實施例所需達成之高透光率衰減式相位移光罩之半 透光層透光率及相位角分別為1〇 %及180。。再者，本實施Therefore, by using the high light transmittance decay method of the present invention, Tiit broadcasts a displacement photomask: 10,000 + τ to use-generally available on the market < photomask substrate: to make the light transmittance higher than 6% attenuation A phase shift mask and an opaque layer are provided to achieve the above-mentioned objects, features, and optimal phase angles of the present invention. Bu specifically mentions the preferred embodiment and cooperates with the following. The detailed description of the town hall is made as shown in the figure, and the process is briefly shown in Figs. 1A to 1H. Manufacturing of a Traditional Attenuation Phase-shifting Mask Figures 2A to 2H show the manufacturing process of a shifting mask according to the present invention. Explanation of symbols 11 ~ transparent area; 13 ~ translucent area; 15 ~ dark area; 12,22 ~ translucent layer; 14,24 ~ translucent layer; 16,26 ~ light-shielding layer; 18,28 ~ light Barrier layer. Examples The high transmittance attenuation phase phase of the embodiment Γ The pattern of the high transmittance attenuation phase shift mask of this embodiment is the same as the figure, and has a dark area 15, a semi-transmissive area 13 and a translucent area η. In addition, the transmittance and phase angle of the semi-transmissive layer of the high-transmittance attenuation phase shift mask required in this embodiment are 10% and 180, respectively. . Moreover, this implementation
第7頁 五、發明說明（5) 例中所使用之化學溶液為NH4〇H : HA : H2〇=l : 1 : 5之S(n 溶液’其對一衰減式相位移光罩所產生之透光率時間變化 率dT及相位角時間變化率dp分巧^〇 〇48%/min及〇. 432。 /min 。 首先如圓2A ’提供一光罩底材，具有一透光率1〇〇%之 石英所構成之透光層22、一透光率6%之MoSiON所構成之半 透光層24及一透光率0%2Cr所構成之遮光層26，並在此光 草底材之遮光層26上覆蓋一光阻層28。Page 7 V. Description of the invention (5) The chemical solution used in the example is NH4OH: HA: H2O = 1: 1: 5 of S (n solution 'which is produced by an attenuation phase shift mask Light transmittance time change rate dT and phase angle time change rate dp are ^ 〇〇48% / min and 432. / min. First, as a circle 2A 'provide a mask substrate with a light transmittance of 10 The light-transmitting layer 22 composed of 0% quartz, a semi-transparent layer 24 composed of MoSiON with a light transmittance of 6%, and a light-shielding layer 26 composed of a light transmittance of 0% 2Cr. The light shielding layer 26 is covered with a photoresist layer 28.
如圖2B ’對半透光區13及透光區丨丨内之光阻層進行曝 光’半透光區13内光阻層28之曝光深度較透光區11内光阻 層28之曝光深度短，且不及遮光層26。 如圖2C ’以二甲越·乙二醇（diethyl glycol dimethyl ether)及甲乙酮（methyl ethyl ketone)之混合 液做為顯影劑進行顯影，使透光區内之遮光層26露出。 如圖2D ’以光阻層28為遮罩依序對遮光層26及半透光 層24進行蝕刻，使相對之透光層22露出。 如圖2E ’再以光阻層28為遮罩，對透光層22進行乾蝕 刻’使透光區11内之透光層22向下凹陷一既定深度，此向 下凹陷之透光層22會增加通過透光區11與半透光區丨3光線 間之相位角差，此增加之量為（l〇-6)x dp/dT = 36。。意即 在此步驟中，先預測出在使用SCI溶液將半透光層24之透 光率由6%增加至10%時會造成之相位角減少量36。，再利 用對透光層22之過度蝕刻使光罩之相位角先增加36。，使 得爾後在使用SC1溶液時可以自然地將相位角做補償，而As shown in FIG. 2B, “exposing the photoresist layer in the semi-transparent area 13 and the translucent area 丨 丨” The exposure depth of the photoresist layer 28 in the translucent area 13 is greater than the exposure depth of the photoresist layer 28 in the translucent area 11. It is shorter than the light shielding layer 26. As shown in FIG. 2C, a mixed solution of diethyl glycol dimethyl ether and methyl ethyl ketone is used as a developer for development, so that the light-shielding layer 26 in the light-transmitting area is exposed. As shown in FIG. 2D ', the light-shielding layer 26 and the semi-transparent layer 24 are sequentially etched with the photoresist layer 28 as a mask, so that the opposite transparent layer 22 is exposed. As shown in FIG. 2E, the photoresist layer 28 is used as a mask, and the light-transmitting layer 22 is dry-etched. The light-transmitting layer 22 in the light-transmitting area 11 is recessed downward to a predetermined depth. The phase angle difference between the light passing through the light-transmitting area 11 and the semi-light-transmitting area 11 will be increased. The amount of this increase is (10-6) x dp / dT = 36. . That is to say, in this step, the phase angle reduction of 36 when the transmittance of the translucent layer 24 is increased from 6% to 10% using the SCI solution is predicted first. Then, the phase angle of the photomask is increased by 36 by using the over-etching of the light-transmitting layer 22. , So that when using SC1 solution, the phase angle can be compensated naturally, and
第8頁 五、發明說明（6) 不改變最後製成之衰減式相位移光罩之相位角。 如圖2F，對光阻層28進行蝕刻，使半透光區13内之遮 光層26露此姓刻步驟為以氧氣為钱刻氣體之乾钱刻。-如圖，再以光阻層28為遮罩對遮光層26進行蝕刻， 使相對之半透光層24露出。 如圖2H，藉由硫酸以及過氧化氫之混合溶液，或其他 適用之溶液將光阻層28剝除，完成一準衰減式相位移光罩 (即半成品）。 最後，將圖2H中之準衰減式相位移光罩浸泡於SCI溶 液中’使半透光層24之透光率由6%增加至10%，同時亦使 準衰減式相位移光罩之相位角減少36。，而補償回180 〇 〇 因此，藉由本實施例中之高透光率衰減式相位移光罩 之製造方法’可以使用一其半透光層透光率為6%之光罩底 材’製造出半透光層透光率為10%之衰減式相位移光罩， 且不改變其相位角。 本發明雖已以較佳實施例揭露如上，但其並非用以限 制本發明。任何熟悉此技藝者，在不脫離本發明之精神和 範圍内，當可做些許之更動與潤飾。因此本發明之保護範 圍當視後附之申請專利範圍所界定者為準。Page 8 V. Description of the invention (6) The phase angle of the final attenuation-type phase-shifting reticle is not changed. As shown in FIG. 2F, the photoresist layer 28 is etched to expose the light-shielding layer 26 in the translucent area 13. The step of engraving is to use oxygen as the money engraving dry money engraving. -As shown in the figure, the light-shielding layer 26 is etched with the photoresist layer 28 as a mask to expose the opposite semi-transparent layer 24. As shown in FIG. 2H, the photoresist layer 28 is peeled off by using a mixed solution of sulfuric acid and hydrogen peroxide, or other applicable solutions to complete a quasi-attenuation phase shift mask (ie, a semi-finished product). Finally, immersing the quasi-attenuation phase shift mask in FIG. 2H in the SCI solution 'increases the light transmittance of the semi-transmissive layer 24 from 6% to 10%, and also makes the phase of the quasi-attenuation phase shift mask Angle is reduced by 36. Therefore, the compensation is returned to 180%. Therefore, by using the manufacturing method of the high-light-transmittance attenuation phase shift mask in this embodiment, 'a mask substrate whose translucent layer has a transmittance of 6% can be used' An attenuated phase shift mask with a transmittance of 10% in the semi-transmissive layer is obtained without changing its phase angle. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with the art can make some changes and retouching without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.
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