1364074 100年10月12日孩正替 六、發明說明： 【發明所屬之技術領域】 [0001]本發明涉及一種微電子領域形成間隙的方法，尤其涉及 一種蝕刻犧牲層形成間隙的方法。 【先前技術】 [00〇2]在微電子製造工藝，特別係在MEMS製造工藝中，常常需 要在兩種材料層之間形成間隙，目前形成間隙的主要方 法係先在兩種需要形成間隙的材料之間沈積一層犧牲層 ，然後通過蝕刻的方法除掉部分犧牲層從而形成間隙。 蝕刻的方法主要有兩種，一種係濕法蝕刻，一種係乾法 f 餘刻 [0003] [0004] [0005] 097100320 濕法蝕刻也叫做化學濕法腐蝕，即通過具有腐蝕性的液 體腐蝕犧牲層的方式除去犧牲層，在兩種材料之間形成 間隙。濕法蝕刻的優點為成本較低且操作簡單，可以選 擇性地蝕刻不同的材料，然，其缺點為各向同性腐蝕， 即橫向和縱向的腐蝕速率相同，導致腐蝕形成的圖形解 析度低。 乾法蝕刻技術係一個非常廣泛的概念，所有不涉及化战 腐蝕液體的蝕刻技術都稱為乾法蝕刻，其中，反應離子 蝕刻係應用最廣泛的乾法蝕刻。乾法蝕刻的優點為具有 各向異性的特點，所蝕刻出的圖形解析度較高，然， 、 其 缺點為對材料的蝕刻無選擇性，蝕刻過程操作複雜， 法實現量產。 ^ 隨著大型積體電路技術和微機械技術的發展，微 于器 件對材料的微細結構的精度要求越來越高，所需在 表單編號_丨 第4頁/共16頁 種 10 1364074 100年10月12日梭正替换頁 材料之間形成的間隙也越來越小，為滿足設計的要求， 犧牲層需儘量薄。然，犧牲層變薄後，在對其蝕刻時產 生兩種負作用：如果用濕法蝕刻，無法滿足微細結構對 精度的要求，且由於間隙很小，犧牲層兩端的材料層易 形成粘附現象；如果用乾法蝕刻，雖然可以很好的控制 微細結構的精度，然，由於乾法蝕刻的反應離子蝕刻具 有較高能量，會因為蟲擊對犧牲層之外的材料造成損傷 ，影響材料的性能。1364074 October 12, 100, Childhood Replacement VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a method of forming a gap in the field of microelectronics, and more particularly to a method of etching a sacrificial layer to form a gap. [Prior Art] [00〇2] In the microelectronic manufacturing process, especially in the MEMS manufacturing process, it is often necessary to form a gap between the two material layers. The current main method of forming the gap is to first form a gap between the two. A sacrificial layer is deposited between the materials, and then a portion of the sacrificial layer is removed by etching to form a gap. There are two main methods of etching, one is wet etching, and the other is dry method. [0003] [0004] [0005] 097100320 Wet etching is also called chemical wet etching, which is sacrificed by corrosive liquid corrosion. The layer layer removes the sacrificial layer, creating a gap between the two materials. The advantages of wet etching are lower cost and simple operation, and different materials can be selectively etched. However, the disadvantage is that isotropic etching, that is, the same rate of corrosion in the transverse direction and the longitudinal direction, resulting in a low degree of patterning of corrosion formation. Dry etching is a very broad concept. All etching techniques that do not involve chemical etching are called dry etching. Among them, reactive ion etching is the most widely used dry etching. The advantage of dry etching is that it has anisotropic characteristics, and the etched pattern has a high resolution. However, its disadvantage is that it does not selectively etch the material, the etching process is complicated, and the method realizes mass production. ^ With the development of large-scale integrated circuit technology and micro-mechanical technology, the accuracy requirements of the micro-structure of the material are higher and higher, and the required number is in the form number _丨第4页/16 pages 10 1036474 100 years On October 12th, the gap formed between the shuttle replacement materials is getting smaller and smaller. To meet the design requirements, the sacrificial layer should be as thin as possible. However, after the sacrificial layer is thinned, it has two negative effects when it is etched: if wet etching is used, the precision of the fine structure cannot be satisfied, and since the gap is small, the material layers at both ends of the sacrificial layer are easily adhered. Phenomenon; if dry etching is used, although the precision of the fine structure can be well controlled, the reactive ion etching of the dry etching has higher energy, which may cause damage to materials other than the sacrificial layer due to insect attack, affecting the material. Performance.
[0006] C. H. Mastrangelo提到一種姓刻犧牲層在兩層材料之[0006] C. H. Mastrangelo mentions a surnamed sacrificial layer in two layers of material
間形成間隙的方法（請參見“Adhesion-related failure mechanisms in micromechanical devices” ， C.H. Mastrange1o, Tribology Letters, Vo 13, P223U 997))。該方法首先在一材料層上沈積一犧牲層 ，通過乾法蝕刻在犧牲層中形成凹槽，然後在犧牲層上 沈積圖形化的另一材料層，使部分犧牲層暴露出，形成 姓刻犧牲層的視窗，因為犧牲層上凹槽的存在，此材料 層上存在一向下的凸點。通過濕法蝕刻去掉犧牲層，在 兩層材料層之間形成間隙，由於凸點的存在可以防止上 下兩層材料粘附的現象，然，由於凸點係由材料層本身 構成，並不能達到較為理想的防止粘附現象，而由於犧 牲層上凹槽的存在，造成在該犧牲層上沈積圖形化的另 一材料層時的工藝複雜，故整個過程工藝繁瑣，不適合 大規模生產。 [0007] 有鑑於此，提供一種工藝簡單，適合大規模生產，且可 有效避免兩材料層之間形成粘附的蝕刻犧牲層形成間隙 097100320 表單編號A0101 第5頁/共16頁 1003375865-0 1364074 100年10月12日修正替換百 [0008] [0009] [0010] [0011] 的方法貫為必要。 【發明内容】 本技術方案涉及一種钱刻犧牲層形成間隙的方法，其包 括以下步驟：提供一基底，在該基底上沈積一第一材料 層；在第一材料層上沈積一犧牲層；在犧牲層上形成圖 形化的第二材料層，使部分所述犧牲層暴露出來，形成 蝕刻視窗；採用乾法從所述蝕刻視窗對犧牲層進行蝕刻 ，直至該犧牲層的厚度減少1 4，同時在犧牲層上形A method of forming a gap (see "Adhesion-related failure mechanisms in micromechanical devices", C.H. Mastrange 1o, Tribology Letters, Vo 13, P223U 997)). The method first deposits a sacrificial layer on a material layer, forms a recess in the sacrificial layer by dry etching, and then deposits another layer of patterned material on the sacrificial layer to expose a portion of the sacrificial layer to form a sacrificial name. The window of the layer, because of the presence of the groove on the sacrificial layer, there is a downward bump on the layer of material. The sacrificial layer is removed by wet etching, and a gap is formed between the two material layers. The presence of the bumps prevents the adhesion of the upper and lower layers of the material. However, since the bumps are composed of the material layers themselves, they cannot be compared. The anti-adhesion phenomenon is ideally prevented, and the process of depositing another layer of patterned material on the sacrificial layer is complicated due to the existence of the groove on the sacrificial layer, so the whole process is cumbersome and unsuitable for mass production. [0007] In view of the above, an etching etching sacrificial layer forming gap 097100320 which is simple in process, suitable for mass production, and can effectively prevent adhesion between two material layers is formed. Form No. A0101 Page 5 of 16 1003375865-0 1364074 The method of correcting the replacement of [0088] [0010] [0011] on October 12, 100 is necessary. SUMMARY OF THE INVENTION The present technical solution relates to a method for forming a gap by a sacrificial layer, comprising the steps of: providing a substrate, depositing a first material layer on the substrate; depositing a sacrificial layer on the first material layer; Forming a patterned second material layer on the sacrificial layer, exposing a portion of the sacrificial layer to form an etched window; etching the sacrificial layer from the etched window by a dry method until the thickness of the sacrificial layer is reduced by 14 Shape on the sacrificial layer
νήΜ BMW 3 :5 成多個凹槽，並在凹槽的側壁上形成保護膜；濕法蝕刻 部分剩餘犧牲層，在第一材料層和第二材料層之間形成 間隙，使犧牲層在第二材料層上靠近第一材料層的一側 形成凸點。 與先前技術相比較，本技術方案所提供的蝕刻犧牲層形 成間隙的方法，直接利用犧牲層本身在第一材料層和第 二材料層的間隙内形成凸點結構，有效避免了第一材料 層與第二材料層之間因為間隙較小而造成相互粘附的現 象，且該方法工藝簡單，易操作，適合量產。 【實施方式】 以下將結合附圖詳細說明本技術方案蝕刻犧牲層形成間 隙的方法。 請參閱圖1及圖2，本技術方案實施例提供一種蝕刻犧牲 層14形成間隙的方法，其具體包括以下步驟： [0012] 097100320 提供一矽基底10，在該矽基底10上沈積一第一材料層12 表單編號A0101 第6頁/共16頁 1003375865-0 100年10月12日修正替換頁 1,364074 [0013] 本技術方案中，沈積的方法可選擇電漿增強化學氣相沈 積法（PECVD)或者低壓化學氣相沈積法（LPCVD)，本實施 例優選為PECVD。 [0014] 所述第一材料層12的材料包括金屬、合金或複合材料， 第一材料層12的厚度不限，本實施例第一材料層12的材 料優選為銅，其厚度為100奈米。 [0015] (二）在第一材料層12上沈積一犧牲層14。ήΜήΜ BMW 3 :5 into a plurality of grooves and forming a protective film on the sidewall of the groove; wet etching part of the remaining sacrificial layer, forming a gap between the first material layer and the second material layer, so that the sacrificial layer is A bump is formed on a side of the two material layers adjacent to the first material layer. Compared with the prior art, the method for forming a gap by etching the sacrificial layer provided by the technical solution directly forms a bump structure in the gap between the first material layer and the second material layer by using the sacrificial layer itself, thereby effectively avoiding the first material layer. The phenomenon of mutual adhesion between the second material layer and the second material layer is small, and the method is simple in process, easy to operate, and suitable for mass production. [Embodiment] Hereinafter, a method of etching a sacrificial layer forming gap by the present technical solution will be described in detail with reference to the accompanying drawings. Referring to FIG. 1 and FIG. 2 , the embodiment of the present invention provides a method for etching a sacrificial layer 14 to form a gap, which specifically includes the following steps: [0012] 097100320 provides a substrate 10 on which a first layer is deposited. Material Layer 12 Form No. A0101 Page 6 / Total 16 Page 1003375865-0 October 12, 2014 Revision Replacement Page 1,364074 [0013] In the present technical solution, the deposition method may be selected by plasma enhanced chemical vapor deposition ( PECVD) or low pressure chemical vapor deposition (LPCVD), this embodiment is preferably PECVD. [0014] The material of the first material layer 12 includes a metal, an alloy or a composite material, and the thickness of the first material layer 12 is not limited. The material of the first material layer 12 in the embodiment is preferably copper, and the thickness thereof is 100 nm. . [0015] (2) depositing a sacrificial layer 14 on the first material layer 12.
[0016] 所述犧牲層14的材料包括二氧化矽或金屬，其厚度與需 要在兩材料層之間形成的間隙的寬度有關，本技術方案 所提供的方法可以蝕刻出的最小間隙寬度為10奈米，故 犧牲層14的厚度大於等於10奈米。本實施例中，犧牲層 14的厚度為4微米。 [0017] (二）在犧牲層14上形成圖形化的第二材料層16。 [0018] 本實施例中，採用金屬剝離工藝在犧牲層14上形成一圖 形化的第二材料層16，其具體包括以下步驟：在犧牲層 14的上表面刷一層光刻膠18後，通過光刻技術蝕刻部分 光刻膠18，形成圖形化的光刻膠18，暴露出部分犧牲層 14 ;通過PECVD或者LPCVD在圖形化的光刻膠18和暴露出 的犧牲層14上沈積第二材料層16 ;將經上述步驟所得的 結構浸入一有機溶液中，除去圖形化的光刻膠18和沈積 在其上的第二材料層16，在犧牲層14上形成一圖形化的 第二材料層16。 1003375865-0 097100320 表單編號A0101 第7頁/共16頁 丄北4074 [0019] [0020] [0021] [0022] [0023] [0024] 100年.10月12日接正替換頁 所述第二材料層16的材料為金屬、合金或複合材料，第 二材料層16的厚度不限，本實施例第二材料層16的材料 優選為金屬銅’其厚度為10〇奈米。 所述有機溶液為丙酮、四氯化碳或氯仿等可溶解光刻膠 的有機物溶液。 所述光刻膠18的厚度大於第二材料層16的厚度，此確保 沈積在光刻膠18上的第二材料層16不會與沈積在暴露出 的犧牲層14上的第二材料層丨6連接《當光刻膠18溶於丙 _中後’沈積在光刻膠18上的部分第二材料層16脫落， 讀 從而在犧牲層14上形成圖形化的第二材料層16。 可以理解，在犧牲層14上形成一圖形化的第二材料層1 6 的方法不限於金屬剝離工藝。 (三）乾法蝕刻部分犧牲層14。 在上述步驟二中，在犧牲層14上形成圖形化的第二材料 層16的同時，由於犧牲層14上光刻膠和部分第二材料層 16的去除，使該部分的犧牲層14暴露出來，形成蝕刻視 4 窗’採用乾法蝕刻中的反應離子蝕刻技術從該蝕刻視窗 對犧牲層14進行蝕刻，直至犧牲層14的厚度減少i - * rnmmm 3 :5 。姓刻之後，在犧牲層14上形成多個凹槽2〇 » 本實施例中，首先通過一定時間的乾法蝕刻一定厚度的 犧牲層14，通過上述時間和厚度計算出此乾法蝕刻的速 度°然後，根據此速度，通過控制蝕刻時間，姓刻犧牲 097100320 表單編號A0101 第8頁/共16頁 1003375865-0 [0025] 1364074 100年.10月12日核正替換百 層14，使犧牲層14的厚度減少1 ，即乾法ϋ刻後犧牲層 的厚度為2微米。 [0026] 在此乾法蝕刻過程中，由於離子對犧牲層14的高能量轟 擊，犧牲層14的材料形成副產物，粘附到凹槽20兩側的 内壁上，在凹槽20兩側的内壁形成一層保護膜。[0016] The material of the sacrificial layer 14 includes ceria or metal, the thickness of which is related to the width of the gap which needs to be formed between the two material layers, and the method provided by the technical solution can etch a minimum gap width of 10 Nano, so the thickness of the sacrificial layer 14 is greater than or equal to 10 nm. In this embodiment, the thickness of the sacrificial layer 14 is 4 μm. [0017] (2) Forming a patterned second material layer 16 on the sacrificial layer 14. [0018] In this embodiment, a patterned second material layer 16 is formed on the sacrificial layer 14 by using a metal stripping process, which specifically includes the following steps: after the photoresist 18 is applied on the upper surface of the sacrificial layer 14, Photolithography etches a portion of photoresist 18 to form patterned photoresist 18, exposing portions of sacrificial layer 14; depositing a second material on patterned photoresist 18 and exposed sacrificial layer 14 by PECVD or LPCVD Layer 16; immersing the structure obtained in the above step in an organic solution, removing the patterned photoresist 18 and the second material layer 16 deposited thereon, and forming a patterned second material layer on the sacrificial layer 14. 16. 1003375865-0 097100320 Form No. A0101 Page 7 of 16 丄北4074 [0019] [0020] [0024] [0024] 100 years. October 12th is replaced by the second page The material of the material layer 16 is a metal, an alloy or a composite material, and the thickness of the second material layer 16 is not limited. The material of the second material layer 16 of the present embodiment is preferably metallic copper having a thickness of 10 nanometers. The organic solution is an organic solution of a photoresist such as acetone, carbon tetrachloride or chloroform. The thickness of the photoresist 18 is greater than the thickness of the second material layer 16, which ensures that the second material layer 16 deposited on the photoresist 18 does not overlap with the second material layer deposited on the exposed sacrificial layer 14. 6 A portion of the second material layer 16 deposited on the photoresist 18 is detached when the photoresist 18 is dissolved in the propylene layer, and is read to form a patterned second material layer 16 on the sacrificial layer 14. It will be appreciated that the method of forming a patterned second material layer 16 on the sacrificial layer 14 is not limited to the metal stripping process. (3) Dry etching a portion of the sacrificial layer 14. In the above step two, while the patterned second material layer 16 is formed on the sacrificial layer 14, the sacrificial layer 14 of the portion is exposed due to the removal of the photoresist on the sacrificial layer 14 and a portion of the second material layer 16. The etching layer 4 is etched from the etching window by a reactive ion etching technique in dry etching until the thickness of the sacrificial layer 14 is reduced by i - * rnmmm 3 : 5. After the last name is formed, a plurality of grooves 2 are formed on the sacrificial layer 14. In this embodiment, the sacrificial layer 14 of a certain thickness is first etched by a dry etching for a certain period of time, and the speed of the dry etching is calculated by the above time and thickness. ° Then, according to this speed, by controlling the etching time, the surname is sacrificed 097100320 Form No. A0101 Page 8 / Total 16 Page 1003375865-0 [0025] 1364074 100 years. October 12 nuclear replacement of the hundred layers 14, so that the sacrificial layer The thickness of 14 is reduced by 1, that is, the thickness of the sacrificial layer after dry etching is 2 micrometers. [0026] During this dry etching process, the material of the sacrificial layer 14 forms by-products due to the high energy bombardment of the sacrificial layer 14 by the ions, adhering to the inner walls on both sides of the groove 20, on both sides of the groove 20. The inner wall forms a protective film.
[0027] 可以理解，上述乾法蝕刻的方法還包括化學輔助離子束 蝕刻或磁控增強離子束蝕刻等。 [0028] (四）濕法蝕刻剩餘犧牲層14，同時在第一材料層12和 第二材料層16之間形成間隙，使犧牲層14在第二材料層 16上靠近第一材料層12的一側形成凸點22。 [0029] 將步驟（三）中所得到的結構置於腐蝕溶液中，浸泡3分 鐘-1小時後，取出上述結構，採用去離子水對其進行清 洗，然後使用氮氣吹幹上述結構。 [0030] 在上述浸泡過程中，犧牲層14在上述腐蝕溶液中逐漸被 腐蝕，溶解到該腐蝕溶液中，因此在第一材料層12和第 二材料層16之間形成間隙。 [0031] 所述腐蝕溶液為一緩衝溶液，包括HF和ΝΗ40Η的混合溶液 、HF和FH40H的混合溶液或HF的水溶液等。該緩衝溶液 的ΡΗ值為3-4. 5。本實施例中，緩衝溶液優選為HF和 ΝΗ40Η的混合溶液，其ΡΗ值為4。 [0032] 在上述犧牲層14的腐蝕過程中，由於凹槽20側壁處的犧 牲層14外包覆了 一層由副產物構成的保護膜，該保護膜 097100320 表單編號 Α0101 第 9 頁/共 16 頁 1003375865-0 1364074 100年10月 12日梭正雜q 可降低凹槽20兩側的内壁的犧牲層14被蝕刻的速度。故 凹槽20側壁的犧牲膚14的腐姓速度相對於凹槽2〇底部的 犧牲層14的腐姓速度較小’因此在上述緩衝溶液中浸泡 之後，犧牲層14的靠近第一材料層12的部分首先被腐蝕 完，在第一材料層12和第二材料層16之間形成間隙，同 時’靠近第二材料層16的犧牲層材料部分剩餘，形成凸 點22，與第二材料層16相連接。 [0033] 可以理解’在一定濕法飯刻速度下，所述凸點22的大小 與濕法触刻的時間有關’當钱刻時間較短時，形成的凸 點22較大’然’如果蚀刻時間太短，便無法在第一材料 層12和第二材料層16之間形成間隙；當蝕刻時間較長時 ，所形成的凸點22較小，然，如果時間太長，則無法在 間隙内形成凸點22。 [0034] 本技術方案所提供的钱刻犧牲層14在兩種材料層之間形 成間隙的方法’在形成間隙的同時，直接利用犧牲層14 本身在第-材料層12和第二材料層16的間隙内形成凸點 22 ’該凸點22可W效避免第-材料層12與第二材料層16 之間因為間隙較小而造成相互粘附的現象，且操作簡單 ，適合量產。 [0035] 综上所述’本發明4已符合發明專利之要件，遂依法提 出申請專利。惟，以上所述者僅為本發明之較佳實施例 ’自不能以此限制本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化， 皆應涵蓋於以下申請專利範圍内。 097100320 【圖式簡單說明】 表單編號> A0101 第10頁/共16頁 1003375865-0 100年10月12日修正替換頁 1364074 [0036] 圖1為本技術方案實施例蝕刻犧牲層形成間隙的過程示意 圖。 [0037] 圖2為本技術方案實施例蝕刻犧牲層形成間隙的方法的流 程圖》 【主要元件符號說明】 [0038] 碎基底：10 [0039] 第一材料層： 12 • [0040] 犧牲層：14 [0041] 第二材料層： 16 [0042] 光刻膠：18 [0043] 凹槽：20 [0044] 凸點：22 • 097100320 表單編號A0101 第11頁/共16頁 1003375865-0[0027] It will be understood that the above dry etching method further includes chemically assisted ion beam etching or magnetron enhanced ion beam etching or the like. (4) wet etching the remaining sacrificial layer 14 while forming a gap between the first material layer 12 and the second material layer 16 such that the sacrificial layer 14 is adjacent to the first material layer 12 on the second material layer 16. A bump 22 is formed on one side. [0029] The structure obtained in the step (3) was placed in an etching solution, and after soaking for 3 minutes to 1 hour, the above structure was taken out, washed with deionized water, and then the above structure was dried using nitrogen gas. [0030] In the above immersion process, the sacrificial layer 14 is gradually etched in the above etching solution to dissolve into the etching solution, thereby forming a gap between the first material layer 12 and the second material layer 16. [0031] The etching solution is a buffer solution, and includes a mixed solution of HF and ΝΗ40Η, a mixed solution of HF and FH40H, or an aqueous solution of HF. 5。 The buffer solution has a ΡΗ value of 3-4. 5. In the present embodiment, the buffer solution is preferably a mixed solution of HF and ΝΗ40 , having a ΡΗ value of 4. [0032] During the etching of the sacrificial layer 14, the sacrificial layer 14 at the sidewall of the recess 20 is covered with a protective film composed of by-products, the protective film 097100320 Form No. 1010101 Page 9 of 16 1003375865-0 1364074 On October 12, 100, the shuttle q can reduce the speed at which the sacrificial layer 14 of the inner wall on both sides of the groove 20 is etched. Therefore, the sacrificial speed of the sacrificial skin 14 on the side wall of the groove 20 is smaller than the decay rate of the sacrificial layer 14 at the bottom of the groove 2'. Therefore, after immersing in the above buffer solution, the sacrificial layer 14 is close to the first material layer 12. The portion is first etched, forming a gap between the first material layer 12 and the second material layer 16, while the portion of the sacrificial layer material adjacent to the second material layer 16 remains, forming the bumps 22, and the second material layer 16 Connected. [0033] It can be understood that, at a certain wet cooking speed, the size of the bump 22 is related to the time of the wet touch. When the time is short, the bump 22 formed is larger. If the etching time is too short, a gap cannot be formed between the first material layer 12 and the second material layer 16; when the etching time is long, the formed bumps 22 are small, but if the time is too long, the gap cannot be A bump 22 is formed in the gap. [0034] The method for forming a gap between two material layers by the money-engraving layer 14 provided by the present technical solution 'is directly utilizing the sacrificial layer 14 itself in the first-material layer 12 and the second material layer 16 while forming the gap. A bump 22 is formed in the gap. The bump 22 can avoid the phenomenon of mutual adhesion between the first material layer 12 and the second material layer 16 due to the small gap, and the operation is simple and suitable for mass production. [0035] In summary, the invention 4 has met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the patent application of the present invention is not limited thereto. Equivalent modifications or variations made by those skilled in the art to the spirit of the invention are intended to be included within the scope of the following claims. 097100320 [Simple description of the drawing] Form number > A0101 Page 10 / Total 16 page 1003375865-0 October 12, 2014 Revision replacement page 1364074 [0036] FIG. 1 is a process of etching a sacrificial layer to form a gap according to an embodiment of the present technical solution schematic diagram. 2 is a flow chart of a method for etching a sacrificial layer to form a gap according to an embodiment of the present technology. [Main component symbol description] [0038] Broken substrate: 10 [0039] First material layer: 12 • [0040] Sacrificial layer : 14 [0041] Second material layer: 16 [0042] Photoresist: 18 [0043] Groove: 20 [0044] Bump: 22 • 097100320 Form No. A0101 Page 11 / Total 16 Page 1003375865-0