1298420 九、發明說明： 【發明所屬之技術領域】 本發明係關於光學微影技術領域，制是關於—種可曝出微小 ‘孤立通孔圖案之相位移光罩及其製作方法。 【先前技術】 在積體€路製程巾，微f彡|^(iithGgraphiepiOees犯成為不可 #或缺的技術，同時，微影製程也是限制元件尺寸(feature—)的主 要因素。藉由微影製程，半導體製造者才能夠順利將電子電路佈 局圖案精確且清晰地娜至半導體晶壯。鄕製駐要是先將 设计的圖案，諸如電路圖案或者是佈植區域佈局圖案等，形成於 -個或多個光罩上，然後再藉由曝紐光罩上賴案糊步進及 掃瞄機台(Stepper&scanner)轉移到半導體晶片上。目前比較成熟 的微影技術是光學微影技術，常制的光源包括有KrF雷射1298420 IX. Description of the Invention: [Technical Field] The present invention relates to the field of optical lithography, and relates to a phase shift mask capable of exposing a tiny 'isolated via pattern and a method of fabricating the same. [Prior Art] In the integrated process, the micro-f彡|^(iithGgraphiepiOees is a technology that cannot be used, and the lithography process is also a major factor limiting the feature size. By lithography process It is the semiconductor manufacturer that can smoothly and accurately align the layout pattern of the electronic circuit to the semiconductor crystal. The formation of the design is to first design the pattern, such as the circuit pattern or the layout pattern of the planting area, in one or more The reticle is then transferred to the semiconductor wafer by the exposure mask stepping and scanning machine (Stepper & scanner). The more mature lithography technology is optical lithography technology. Light source includes KrF laser
• (248nm)、ArF雷射(193nm)以及F2雷射(157nm)等，其中又以KrF 雷射與ArF雷射曝光技術最為成熟，而非光學(n〇n_〇ptical)微影技 術，例如電子束(e_beam)，則在發展階段。 隨著元件堆積密度(packing density)的增加，元件(例如閘極)之 ’間的間距(pitch)也隨之縮小，造成在光罩上經常具有呈緊密排列之 密集線條/通孔(dense line/hole)圖案、半密集(或半孤立)圖案或孤立 的線條/通孔(isolated line/hole)圖案。為了有效曝出這些圖案，微影 製程中通常採用相位移光罩(PSM)，並配合不同光源型態，來降低 5 1298420 繞射效應所引起的問題，以增加影像對比，提高解析能力。 目前常使用到的相位移光罩(PSM)主要有兩種··交替式相位移 光罩(alternatingPSM)與衰減式相位移光罩(attenuatingPSM)，其中 父#式相位移光罩主要是在鉻線條feature)間加入相位移 (shifter)材料，使得入射光產生18〇度的相位差，降低繞射所引起 的干涉效應，使鉻膜圖案邊界的對比提高。衰減式相位移光罩， • 其概念是將有圖案的區域加入適當的材料，使得其與無圖案區域 之相位差達180度，並能随得適#的穿透率，提高曝光深度， 以滿足產能的絲。然而，傳統她移光罩設計所制的瓶頸是 無法曝出令人滿意的極小尺寸孤立通孔圖案。 【發明内容】 因此，本發明的主要目的即在提供一種可曝出微小孤立通孔圖 案之相位移光罩設計及其製作方法。 根據本㈣之較佳實施例，—麵鱗出微小通關案的相位 移光罩，包财-透光基板，具有—上表面；—不透光材料層， 鑛於该透絲板的上表面’其中該不透光材料層具有一開口，暴 ^出下方該透絲板醜定透光區域。射軸定透絲域包括 有·十字形第-相位移以及除了斜字形第—她移區域 ==第二她顏域，其t通過該十字形第—相位移區域的光 線與通過該第二相位顏域的光線的相位差為⑽度。 1298420 為了使貴審查委員能更近-步了解本發明之特徵及技術内 容’請參閱以下有關本發明之詳細說明與附圖。然而所附圖式僅 供參考與辅助說明用，並非用來對本發明加以限制者。 【實施方式】 請參閱第1圖以及第2圖，其中第！圖繪示的是依據本發明較 佳實施例可曝出微小孤立通孔圖案之相位移鮮1()的佈局示意 圖；第2圖繪示的是本發明相位移光罩1〇沿著帛i圖切線w，之 剖面示意圖。如第1圖所示，相位移光罩1G包括有—透光基板 1〇〇 ’其係由透光材料例如石英等所構成。在透光基板励的上表 面上鍍有-不透光材料層12G，例如鉻層，可完全阻播光線的穿 透。不透光材料層120具有-開σ 122，暴露出下方透光基板ι〇〇 的預定透光區域刚。預定透光區域刚容許特定波長的光線通過 相位移光罩ω，並投射在塗佈在晶圓的光阻層上，於其中形成微 小孤立通孔圖案。 〃本發明之主要雜在於矩形的預定透光區域_包括有十字形 第-透光區域〗42,係以侧方式將透光基板觸向下侧至第二 基板厚度tl。矩形的預定透光區域⑽3包括有除了此十字形第 -透光區域H2以外的第二透光區域144，射第二透光區域⑷ 具有-第二基板厚度t2 ’且該第二基板厚度t2較該第一基板厚度 t!厚’如第2 _示’如此使得通過十字形第—透光區域1二 線與通過第二透光輯144的光線的相位差為⑽度。第二透光 1298420 區域144 ±要由四個位於矩形的預定透光區域14〇的四個角落的 彼此獨立不相連的矩形子區域所構成。 以下即藉由第3圖至第6圖本發明可曝出微小孤立通孔圖 案之相位移光罩10的製作步驟。首先，如第3圖所示，提供一透 光基板1〇〇，例如石英基板，且其上鑛有一不透光材料層12〇，例 如鉻層，可完全阻擋光線的穿透。 如第4圖所示’接著在不透光材觸12()上形成_光阻層魯 並隨即利用微影製程在光阻層42〇内形成一開口似。接下來，利 祕刻方式經由光阻層420的開口 422依序向下钱刻不透光材料 層120以及透光基板100,形成凹陷區域43〇並餘刻到預定的深度 才停止。此時，即完成前述針字形第—透+光區域的製作。 接著’如第5圖所示，在去除光阻層42〇之後，再於不透光材 料層120上形成-光阻層52〇，並隨即利用微影製程在光阻層52〇 内形成-矩形開口 522。矩形開口 522暴露出前述的凹陷區域 430，以及部分的不透光材料層12〇。 接下來如第6圖所示’選擇性的姓刻經由矩形開口 22所暴 露出來的不透光材料層120，形成開口 122，去除光阻層52〇，完 成前述第二透光區域144的製作。 1298420 以上所述僅為本發明之較佳實施例，凡依本發明申請 所做之均等變化與修飾，皆應屬本發明之涵蓋範圍。 圉 【圖式簡單說明】 第1_示的是依據本發明較佳實施例可曝出微小孤立通孔圖 案之相位移光罩的佈局示意圖。 一第2圖繪示的是本發明相位移光罩沿著第1圖切線w，之剖面 圖案之相位移 第3圖至第6圖說明本發明可曝出微小孤立通孔 光罩的製作步驟。 【主要元件符號說明】 1〇 相位移光罩 120不透光材料層 140預定透光區域 144第一透光區域 422 開口 520光阻層 100 透光基板 122 開口 142 十字形第一透光區域 420 光組層 430 凹陷區域 522 開口• (248nm), ArF laser (193nm) and F2 laser (157nm), among which KrF laser and ArF laser exposure technology is the most mature, rather than optical (n〇n_〇ptical) lithography technology. For example, the electron beam (e_beam) is in the development stage. As the packing density of the component increases, the pitch between the components (such as the gate) also shrinks, resulting in dense lines/through holes that are closely arranged on the mask. /hole) pattern, semi-dense (or semi-isolated) pattern or isolated line/hole pattern. In order to effectively expose these patterns, a phase shift mask (PSM) is usually used in the lithography process, and different light source types are used to reduce the problems caused by the diffraction effect of 5 1298420 to increase image contrast and improve resolution. Currently used phase shift masks (PSM) mainly have two kinds of alternating phase shift masks (alternatingPSM) and attenuated phase shift masks (attenuatingPSM), wherein the parent phase shift mask is mainly in chromium. A phase shifter material is added between the lines to make the incident light produce a phase difference of 18 degrees, reducing the interference effect caused by the diffraction, and improving the contrast of the chrome film pattern boundary. Attenuated phase-shift reticle, • The concept is to add the patterned area to the appropriate material so that it has a phase difference of 180 degrees from the unpatterned area, and can increase the exposure depth with the penetration rate of Silk that meets the capacity. However, the bottleneck made by the conventional hermetic cover design is that it is impossible to expose a satisfactory extremely small isolated through-hole pattern. SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a phase shift mask design that can expose a small isolated via pattern and a method of fabricating the same. According to the preferred embodiment of the present invention, the phase shift mask of the micro-circumference case, the wealth-transparent substrate has an upper surface, and the opaque material layer is deposited on the upper surface of the light-permeable plate. 'The opaque material layer has an opening that violently passes out the opaque light-transmissive area of the permeable plate below. The axis of the fixed axis includes a cross-phase displacement and a cross-shaped first-sheer region==second her field, the t passing through the cross-phase-shifting region and passing the second The phase difference of the light in the phase field is (10) degrees. 1298420 In order to enable the reviewing committee to get closer to the features and technical contents of the present invention, please refer to the following detailed description of the invention and the accompanying drawings. The drawings are to be considered in all respects as illustrative and not restrictive. [Embodiment] Please refer to Figure 1 and Figure 2, where the first! The figure shows a layout diagram of a phase shift fresh 1() which can expose a minute isolated via pattern according to a preferred embodiment of the present invention; and FIG. 2 shows a phase shift mask of the present invention along a 帛i Figure cut line w, a schematic view of the section. As shown in Fig. 1, the phase shift mask 1G includes a light-transmitting substrate 1'' which is made of a light-transmitting material such as quartz or the like. The upper surface of the light-transmitting substrate is plated with an opaque material layer 12G, such as a chrome layer, to completely block the penetration of light. The opaque material layer 120 has an -open σ 122 that exposes a predetermined light-transmissive region of the underlying transparent substrate ι. The predetermined light-transmitting region just allows light of a specific wavelength to pass through the phase shift mask ω and is projected on the photoresist layer coated on the wafer to form a minute isolated via pattern therein. The main difference of the present invention is that the predetermined light-transmissive region of the rectangle _ includes a cross-shaped light-transmitting region 42, which touches the light-transmissive substrate to the lower side to the second substrate thickness t1 in a side manner. The rectangular predetermined light-transmitting region (10) 3 includes a second light-transmitting region 144 other than the cross-shaped light-transmitting region H2, and the second light-transmitting region (4) has a second substrate thickness t2' and the second substrate thickness t2 The thickness of the first substrate is thicker than the thickness of the first substrate as shown in FIG. 2 such that the phase difference between the second line passing through the cross-shaped light-transmitting region 1 and the light passing through the second light-transmitting portion 144 is (10) degrees. The second light transmissive 1298420 region 144 is formed by four rectangular sub-regions that are independent of each other at four corners of the rectangular predetermined light-transmissive region 14A. The following is a manufacturing step of the phase shift mask 10 which can expose a minute isolated through hole pattern by the present invention by Figs. 3 to 6 . First, as shown in Fig. 3, a light-transmitting substrate 1 is provided, such as a quartz substrate, and a layer of opaque material 12, such as a chrome layer, is deposited thereon to completely block the penetration of light. As shown in Fig. 4, a photoresist layer is formed on the opaque material contact 12 (), and an opening is formed in the photoresist layer 42 by a lithography process. Next, the secret engraving mode sequentially etches the opaque material layer 120 and the transparent substrate 100 through the opening 422 of the photoresist layer 420 to form the recessed region 43 〇 and waits until a predetermined depth is stopped. At this time, the formation of the aforementioned pin-shaped first-permeation + light region is completed. Then, as shown in FIG. 5, after the photoresist layer 42 is removed, a photoresist layer 52 is formed on the opaque material layer 120, and then formed in the photoresist layer 52 by a lithography process - A rectangular opening 522. The rectangular opening 522 exposes the aforementioned recessed area 430, as well as a portion of the opaque material layer 12A. Next, as shown in FIG. 6, the selective opaque layer 120 is formed by the opaque material layer 120 exposed through the rectangular opening 22, and the photoresist layer 52 is removed to complete the fabrication of the second light-transmissive region 144. . 1298420 The above is only the preferred embodiment of the present invention, and all variations and modifications made by the present application are intended to be within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the layout of a phase shift mask which can expose a minute isolated through hole pattern according to a preferred embodiment of the present invention. 2 is a phase shifting reticle of the present invention along the first line tangential w, the phase shift of the cross-sectional pattern of FIGS. 3 to 6 illustrates the manufacturing steps of the present invention for exposing the micro-isolated through-hole reticle. . [Main component symbol description] 1 phase shift mask 120 opaque material layer 140 predetermined light transmitting region 144 first light transmitting region 422 opening 520 photoresist layer 100 transparent substrate 122 opening 142 cross first light transmitting region 420 Light group layer 430 recessed area 522 opening