1240589 玖、發明說明 (發明說明應敘明··發明所屬之技術領域、先前技術、內容、實施方式及圖式簡單說明） 【發明所屬之技術領域】 本發明係一種電容式矽基微麥克風及其製造方法，其 係由一背板晶片與一振動晶片相互接合而成。 5【先前技術】 近年來，麥克風產品整體之發展趨勢除了要求輕薄短 小之外，更必須具備更佳之靈敏度、穩定性與輸出表現， 方能滿足客戶之需求，也因此使得微麥克風之結構設計日 益複雜與多樣化。 10 一般習用之麥克風係屬於由單一晶片所構成之單晶片 式麥克風，其製程方法係先以薄膜沉積法完成一背板、若 干音孔、一基座，以及一位於背板與基座間之犧牲層，再 進行該基座之蝕刻，並移除該犧牲層以形成一振膜，因此 該麥克風之尺寸設計將受到該犧牲層厚度的限制，一旦欲 15 改變犧牲層厚度，則後續製程也必須一併修改，否則最後 結構的殘留應力會有所不同，將影響到該振膜之特性，導 致設計上的彈性很小，也因而難以達到最佳之靈敏度與輸 出表現。 此外，另一種習用之麥克風係屬於由至少二晶片所構 20 成之晶片接合式麥克風，其係先應用體加工製程完成個別 晶片之加工，隨後利用晶圓接合技術加以組裝接合，用以 完成麥克風之製作，不僅製程大幅簡化，同時可輕易改變 二晶片間之間隙，且不影響該麥克風之材料特性。 然而，一般接合式麥克風多半由三個以上之晶片所組 ϋ續次頁（發明說明頁不敷使用時，請註記並使用續頁） -5- 1240589 _ 發明說明; 成，製程上仍然存在一定的複雜度，另外，一般晶片接合 式麥克風之電極打線區域無法外露，導致後續打線製程的 難度增加。 5 【發明内容】1240589 发明 Description of the invention (the description of the invention should be stated ... the technical field to which the invention belongs, the prior art, the content, the embodiments and the drawings are briefly explained) [Technical Field to which the Invention belongs] The present invention is a capacitive silicon-based micro microphone and The manufacturing method is formed by bonding a back plate wafer and a vibration wafer to each other. 5 [Previous technology] In recent years, in addition to the requirements of thin, light and short, the overall development trend of microphone products must have better sensitivity, stability and output performance in order to meet customer needs. Complex and diverse. 10 The conventional microphone is a single-chip microphone composed of a single chip. The manufacturing method is to first complete a back plate, a number of sound holes, a base, and a sacrifice between the back plate and the base. Layer, and then etch the base, and remove the sacrificial layer to form a vibrating film, so the size design of the microphone will be limited by the thickness of the sacrificial layer. Once the thickness of the sacrificial layer is changed by 15, subsequent processes must also be performed. Modify it together, otherwise the residual stress of the final structure will be different, which will affect the characteristics of the diaphragm, resulting in a small design flexibility, and it is difficult to achieve the best sensitivity and output performance. In addition, another conventional microphone is a wafer-bonded microphone composed of at least two wafers. It first uses a bulk processing process to complete the processing of individual wafers, and then uses wafer bonding technology to assemble and bond to complete the microphone. The production process is not only greatly simplified, but also the gap between the two chips can be easily changed without affecting the material characteristics of the microphone. However, most general joint microphones are composed of more than three chips. Continued pages (When the description page of the invention is insufficient, please note and use the continued page.) -5- 1240589 _ Description of the invention; In addition, the electrode bonding area of a general wafer-bonded microphone cannot be exposed, resulting in increased difficulty in subsequent wiring processes. 5 [Contents of the Invention]
本發明之主要目的在於提供一種電容式矽基微麥克風 及其製法，其結構簡易，製程大幅簡化，因而具有較低之 製作成本。 本發明之次一目的在於提供一種電容式矽基微麥克風 10 及其製法，其結構之設計彈性高，因而可在小尺寸的要求 下’滿足各式之設計要求。 因此，本發明係提供一種電容式矽基微麥克風，其包 含有一背板晶片，以及一振動晶片，其中： 該背板晶片係具有相對之一第一面與一第二面，其中 15 該第一面係設有至少一音孔，以及一與該音孔電氣連接之 第一電極，而該第二面則開設有一連通該音孔之共振槽。The main purpose of the present invention is to provide a capacitive silicon-based micro microphone and a manufacturing method thereof, which have a simple structure and a greatly simplified manufacturing process, and thus have a low manufacturing cost. A second object of the present invention is to provide a capacitive silicon-based micro microphone 10 and a method for manufacturing the same. The structure is highly flexible in design, so that it can meet various design requirements under the requirement of a small size. Therefore, the present invention provides a condenser silicon-based micro microphone, which includes a back plate wafer and a vibration wafer, wherein: the back plate wafer has a first surface and a second surface opposite to each other, of which 15 One surface is provided with at least one sound hole and a first electrode electrically connected to the sound hole, and the second surface is provided with a resonance groove communicating with the sound hole.
該振動晶片係設有一基座，一覆蓋於該基座表面之振 動膜，以及一與該振動膜電氣連接之第二電極，此外，該 基座更開設有一連通該振動膜與外界之音源槽； 20 而該二晶片係以該第一面對應於該振動膜之方式進行 接合，並使該第一電極與該第二電極完成電氣連接。 而本發明之製法則包含有下列步驟： a. 製作該背板晶片與該振動晶片； b. 將該振動晶片與該背板晶片進行接合，即完成本發明 -6- 1240589 _ 發明說明_胃 微麥克風之製作。 此外，本發明之製法更可包含有一切割步驟c，以使 該第一電極之打線區域外露，以便於後續之作業進行。 5 【實施方式】 為了詳細說明本發明之構造及特點所在，茲舉以下之 較佳實施例並配合圖式說明如后，其中：The vibrating chip is provided with a base, a vibrating film covering the surface of the base, and a second electrode electrically connected to the vibrating film. In addition, the base is further provided with a sound source that connects the vibrating film to the outside. 20; and the two wafers are bonded in such a manner that the first surface corresponds to the vibration film, and the first electrode and the second electrode are electrically connected. The manufacturing method of the present invention includes the following steps: a. Fabricating the back plate wafer and the vibrating wafer; b. Bonding the vibrating wafer and the back plate wafer to complete the present invention-6- 1240589 _ Invention Description _ stomach Production of micro microphones. In addition, the manufacturing method of the present invention may further include a cutting step c, so that the wiring area of the first electrode is exposed, so as to facilitate subsequent operations. 5 [Embodiment] In order to explain the structure and characteristics of the present invention in detail, the following preferred embodiments are described in conjunction with the drawings as follows, where:
第一圖係本發明麥克風之剖視圖； 第二圖係本發明背板晶片之製作流程圖； 10 第三圖係本發明振動晶片之製作流程圖；以及 第四圖係本發明背板晶片與振動晶片接合後之剖視 圖。 首先，請參閱第一圖所示，本發明所提供一種電容式 矽基微麥克風10，其係主要包含有一背板晶片20，以及一 15 位於該背板晶片20下方之振動晶片30，其中：The first diagram is a cross-sectional view of a microphone of the present invention; the second diagram is a flowchart of making a backplane wafer of the present invention; the third diagram is a flowchart of making a vibrating wafer of the present invention; and the fourth diagram is a backplane wafer and vibration of the present invention A cross-sectional view of the wafer after bonding. First, referring to the first figure, the present invention provides a capacitive silicon-based micro microphone 10, which mainly includes a back plate wafer 20, and a vibration chip 30 located below the back plate wafer 20, wherein:
該背板晶片20係具有相對之一第一面21與一第二面 22，其中該第一面21係設有一磊晶層23，一摻雜P+離子 之傳導層24，複數個穿透該磊晶層23與該傳導層24之音 孔25，以及一與該傳導層24電氣連接之第一電極26，而 20 該第二面22則開設有一連通該等音孔25之共振槽27。 再請參閱第二圖，該背板晶片20之製法係包含有下列 步驟： a.提供一表面具有該蟲晶層23之晶圓A，再將P+離子 植入該磊晶層23之表面以形成該傳導層24 ; 1240589 _ 發明說明$賣胃 b·利用感應耦合電漿（Inductively Coupled Plasma，ICP) 蝕刻出該等穿透該傳導層24與該磊晶層23之音孔25 ; c.利用熱氧化製程於該背板晶片20之第一面21與第 二面22分別形成一第一氧化層281與一第二氧化層282 ; 5 d.將該第一氧化層28開設一連通該傳導層24與外界 之接觸口 283，再於該第一氧化層281之表面形成與該傳 導層24電氣連接之該第一電極26,以及二金屬接合點29;The backplane wafer 20 has a first surface 21 and a second surface 22 opposite to each other, wherein the first surface 21 is provided with an epitaxial layer 23, a conductive layer 24 doped with P + ions, and a plurality of penetrating layers. The epitaxial layer 23 and the sound hole 25 of the conductive layer 24, and a first electrode 26 electrically connected to the conductive layer 24, and 20 the second surface 22 is provided with a resonance groove 27 communicating with the sound holes 25 . Please refer to the second figure again. The manufacturing method of the backplane wafer 20 includes the following steps: a. Provide a wafer A having the worm crystal layer 23 on its surface, and implant P + ions on the surface of the epitaxial layer 23 to Forming the conductive layer 24; 1240589 _ Description of the invention b. Stomach holes 25 penetrating the conductive layer 24 and the epitaxial layer 23 are etched out using an inductively coupled plasma (ICP); c. A thermal oxidation process is used to form a first oxide layer 281 and a second oxide layer 282 on the first surface 21 and the second surface 22 of the backplane wafer 20 respectively; 5 d. The contact layer 283 of the conductive layer 24 and the outside world, and then the first electrode 26 electrically connected to the conductive layer 24 and a two-metal junction 29 are formed on the surface of the first oxide layer 281;
e.將該第二氧化層282部分去除，且於對應該等音孔 25之位置蝕刻出該共振槽27，隨後去除該等音孔25底部 10 之第一氧化層281以及殘餘之第二氧化層282。 如此即可完成該背板晶片20之製作，其中步驟c之熱 氧製程係具有三種作用：一為可完成電氣隔絕，二為利用 其加熱過程可完成離子植入後之回火，三是可形成蝕刻該 共振槽27時之蝕刻停止層，藉以提高產品之良率。 15 該振動晶片30係設有一基座31，一覆蓋於該基座31e. The second oxide layer 282 is partially removed, and the resonance groove 27 is etched at a position corresponding to the sound holes 25, and then the first oxide layer 281 at the bottom 10 of the sound holes 25 and the remaining second oxide are removed. Layer 282. In this way, the production of the backplane wafer 20 can be completed. The thermal oxygen process of step c has three functions: one is to complete electrical isolation, the other is to use its heating process to complete the tempering after ion implantation, and the third is to An etching stop layer is formed when the resonance groove 27 is etched to improve the yield of the product. 15 The vibrating chip 30 is provided with a base 31 and a cover 31
表面之振動膜32，以及一與該振動膜32電氣連接之第二 電極33，此外，該振動膜32係由一氧化矽（SiO)材質之氧 化層34, 一氮化矽（SiN)材質之介電層35,以及一金屬材 質之導電層36所疊合而成，而該基座31更開設有一連通 20 該振動膜32與外界之音源槽37。 再請參閱第三圖所示，該振動晶片30之製法係包含有 以下步驟： a.提供一晶圓B，並於該晶圓B之表面依序形成該氧 化層34與該介電層35 ; -8- 1240589 _ 發明說明#賣Μ b·將該晶圓Β —側面之氧化層34與介電層35部分去 除，並以氫氧化鉀（KOH)溶液蝕刻形成該音源槽37與該 振動膜32 ; c.於該振動膜32之表面形成該金屬導電層36,並於該 5 介電層35之表面形成該第二電極33，以及二金屬接合點 38。 因此，完成該背板晶片20與該振動晶片30之製作後， 即可將該二晶片20&30之金屬接合點29&38相對應，以表 面附著技術（Surface Mount Technology, SMT )進行接合’ 10 並同時完成該第一電極26與該第二電極33之電氣連接。 接合組裝完成後，如第四圖所示，該振動晶片30於步 驟b中亦可同時蝕刻出一 V型槽39,因而可選用適當的刀 具進行切割，使該第一電極26之打線區域外露，不僅有利 於後續接腳打線之製程進行，更可簡化製作程序。 15 藉此，本發明之電容式矽基微麥克風係具有簡單之製 作流程以降低製作成本，設計上具備彈性，且蝕刻作業均 設有蝕刻停止層，以不需沿用過去利用蝕刻犧牲層的作 法，而可提高產品製作之良率。另外，利用部分切割使打 線區域外露之作法更可有效解決過去線路接點無法外露之 20 問題。 值得一提的是，本發明之背板晶片與振動晶片之接合 方式係不以前述實施例所提之金屬接合點為限，亦可將其 改為金屬接合圈，或其等效之晶圓接合方法，均應落入本 專利之保護範圍内。 -9- 25 1240589 _ 發明說明 【圖式簡單說明】 第一圖係本發明麥克風之剖視圖。 第二圖係本發明背板晶片之製作流程圖。 第三圖係本發明振動晶片之製作流程圖。 5 第四圖係本發明背板晶片與振動晶片接合後之剖視 圖0 【圖式符號說明】 10麥克風 10 20背板晶片 21第一面 22第二面 • 23蠢晶層 24傳導層 25音孔 26第一電極 27共振槽 281第一氧化層 282第二氧化層 283接觸口 29金屬接合點 30振動晶片 31基座 32振動膜 15 33第二電極 34氧化層 35介電層 36金屬層 37音源槽 38金屬接合點 39V型槽 Α&Β晶圓 • -10-A vibrating film 32 on the surface, and a second electrode 33 electrically connected to the vibrating film 32. In addition, the vibrating film 32 is made of a silicon oxide (SiO) oxide layer 34, a silicon nitride (SiN) material. The dielectric layer 35 and a conductive layer 36 made of metal are superimposed, and the base 31 is further provided with a sound source groove 37 connecting the vibration film 32 to the outside. Please refer to FIG. 3 again, the manufacturing method of the vibrating wafer 30 includes the following steps: a. Provide a wafer B, and sequentially form the oxide layer 34 and the dielectric layer 35 on the surface of the wafer B. -8- 1240589 _ Description of the invention # 卖 Ｍ b · The wafer B-the oxide layer 34 and the dielectric layer 35 on the side are partially removed, and the sound source groove 37 and the vibration are formed by etching with a potassium hydroxide (KOH) solution Film 32; c. Forming the metal conductive layer 36 on the surface of the vibration film 32, and forming the second electrode 33 and a two-metal junction 38 on the surface of the 5 dielectric layer 35. Therefore, after the fabrication of the backplane wafer 20 and the vibrating wafer 30 is completed, the two wafers 20 & 30 can be connected to the metal joints 29 & 38, and they can be joined using Surface Mount Technology (SMT). 10 At the same time, the electrical connection between the first electrode 26 and the second electrode 33 is completed. After the bonding and assembly is completed, as shown in the fourth figure, the vibrating wafer 30 can also be etched with a V-shaped groove 39 in step b. Therefore, an appropriate cutter can be used to cut the exposed area of the first electrode 26. , Which is not only conducive to the subsequent pin bonding process, but also can simplify the production process. 15 In this way, the capacitive silicon-based micro-microphone of the present invention has a simple manufacturing process to reduce manufacturing costs, has a flexible design, and is provided with an etching stop layer for the etching operation, so that it does not need to follow the method of using the etching sacrificial layer , And can improve the yield of product production. In addition, the use of partial cutting to make the wiring area exposed can effectively solve the problem of the past that the line contacts could not be exposed. It is worth mentioning that the bonding method of the backplane wafer and the vibrating wafer of the present invention is not limited to the metal bonding points mentioned in the foregoing embodiments, and it can be changed to a metal bonding ring or its equivalent wafer. The joining methods should all fall within the protection scope of this patent. -9- 25 1240589 _ Description of the invention [Brief description of the drawings] The first figure is a sectional view of the microphone of the present invention. The second figure is a manufacturing flow chart of the backplane wafer of the present invention. The third figure is a manufacturing flow chart of the vibration wafer of the present invention. 5 The fourth diagram is a cross-sectional view of the backplane wafer and the vibrating wafer of the present invention after being joined. 0 [Illustration of Symbols] 10 Microphone 10 20 Backplane wafer 21 First surface 22 Second surface 23 Stupid crystal layer 24 Conductive layer 25 Sound hole 26 First electrode 27 Resonant groove 281 First oxide layer 282 Second oxide layer 283 Contact opening 29 Metal junction 30 Vibration wafer 31 Base 32 Vibration film 15 33 Second electrode 34 Oxidation layer 35 Dielectric layer 36 Metal layer 37 Sound source Groove 38 Metal junction 39V-shaped groove A & B wafer • -10-