—mt065 、 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種表面聲波濾波器（Surface Ac〇ustic Wave filter; SAW Filter)。特別是有關於一種利用鑽石（Diam〇n幻 層或類鑽碳(Diamond like Carbon)層之高聲速及優越之震動 性，結合微波帶線(Microwave Microstrip line)及交叉指狀 電極轉換器（Interdigital Transducers; IDTs)形成之表面簦 波濾波器。 【先前技術】 不近年來隨著社會的高度資訊化，各種無線通訊系統的迫切 需求與快速地成長，輕、薄、短、小的通訊系統及設備研發， 為一很重要的課題。傳統的濾波器體積大、重量重，不易於積 體化；而平面濾波器則可以解決這些問題。表面聲波(Surface Acoustic Wave，SAW)濾波器具有較小尺寸和較輕重量的特 性；然而以石英（Quartz)、鈮酸鋰(LiNbOO、鈕酸鋰(LiTa〇3)、 氮化銘(A1N)、氧化鋅(Zn〇)等壓電材料製作之平面濾波器，其 使用頻率一般均低於lGHz(l//m IDTs)，為了達到高於1GHz 的使用頻率，則就需要較高的機電耦合係數及高速的表面傳播 速率。 表面聲波濾波器元件是在壓電基板或壓電薄膜上製作交 指叉狀電極轉換器電極，當輸入端的IDTs加上交流訊號後， 在兩電極之間會產生交變電場，電場下方的壓電體因逆壓電效 應而產生應變（Strain)，進而激發出表面聲波，經由壓電材 料，面傳遞，再由輸出端IDTs的正壓電效應將聲波訊號轉為 電氣訊號輸出。由於表面聲波元件的振動範圍僅在壓電基板的 表面附近，因此也可以在半導體基板上濺鍍一層壓電薄膜（如 AIN、ZnO)，如此可達到表面聲波元件的積體化。 1241065 二般而言，表面聲波濾波器因雙向傳輸損失、電極阻抗不 匹配損失、基板傳輸損失、體波干擾、波束散佈損失、IDTs 上的寄生電阻、延遲傳輸線之散射電容等因素，而造成表面聲 波/慮波裔之插入損失大；由於表面聲波濾、波器的中心頻率，取 決於交叉，狀兩電極間的距離及壓電元件材料本身被激勵而 產生，面聲波的相速度(vs=又f)。所以想使表面聲波濾波器在 GHz範圍的高頻工作，那就是縮小交叉指狀兩電極間的距離或 選擇使用表面聲波之相速度較快的壓電材料，若以128。Y-cut LiNb〇3之壓電材料為基板，當要在GHz範圍的高頻工作時，那 麼設計IDTs電極之間距，則必須小於丨以下的尺寸才能達 成。因此若要提升表面聲波濾波器特性的方法，可根據如下的 方法，即可輕易達到lGHz以上的工作頻率，並有效減少其插 入損失與增加其頻寬。 、抑因此本發明乃針對先前技術之缺點，提出一種表面聲波濾 波器，具有高效率、低損失、高功能，使濾、波器之體積最小化: 而其響應表現最佳化。 【發明内容】 本發明之目的在提供一種表面聲波濾波器，利用鑽石層或 麵碳層之高聲速及優越之震動性，結合微麟帶線與交又指 狀電，轉換H ’使微波與表面聲波交互制，以提高工作頻率 声戍目λ在提供—種表面聲波遽波器，利用鑽石 廣iff層南讀電壓及零溫度效應及微波微帶線與交 叉才曰狀電極轉換器耦合，以降低插入損失。 導體ΐίΓ目的在提供—種表面聲波誠器，利用與半 i之製程，並可與主動元件製條同—基板上，利 f衣成早石微波積體電路MMIC (Monolithic MiCrowave ntegrated Circuit)元件，大幅度地簡化元件的體積與面 1241065 積’並有效地降低其製作成本。 為達成上述目的及其他目的，本發明 表面聲波濾、波n 鑽石層或_碳層之“ Ϊ性二ίί微波微帶線及交叉指狀電極轉換器形成，至少包 έ · 一塊基板，其上有微波電路，·一層錯展 ί上傳，用^龍鶴:形成;^石^ • 益電效應，—組微帶線開迴路譜振器（c〇upled microstrip square open-loop resonat〇rs)及交 電Ϊf上，微帶線開迴路_器在輸入端两 個相對，』以父叉才曰狀電極#合。輸出端亦两個相對，立間 亦以交叉指狀電極耦合；-伽金屬薄膜，形成於背面， 作接地用之用。. 胃 =本發明之以上及其他目的及優點參考以下之參照圖示及 最佳實把例之說明而更易完全瞭解。 【實施方式】 參考第1圖，第1圖係顯示依據本發明之實施例具有鑽石 層結構之微波微帶線與表面聲波IDTs交錯耦合之濾^器構造 透視圖。在矽（Si)基板或GaAs基板102上以微波化學氣相 沉積(Microwave CVD)形成10//m至30//m(較佳為2〇 厚之 鑽石層（或類鑽石層）104，然後再於鑽石1 〇4上以射頻濺鍍(RF Sputter)方式，形成〇· 5//m至3//m(較佳為1 _)厚之氧^匕辞 ^ZnO)或氮化銘(A1N)作為壓電薄膜106，再鑛上100nm至1〇〇〇 又厚之銘（A1) ’以微影姓刻形成1 //m至10//in寬之方形輕合微 帶線開迴路諧振器108與0· 1 //m至5寬，及與寬度相等之 間隔之表面聲波交叉指狀電極轉換器11〇，形成微波微帶線與 表面聲波IDTs交錯耦合之濾波器100。微帶線開迴路譜振^ 在輸入端两個相對，其間以交叉指狀電極耦合。輸出端亦两j固 相對’其間亦以交叉指狀電極輕合。開迴路缺口 112為開迴路 1241065 (open-loop)之用。然後沉積一層氧化矽（si〇2)作保護層。最 後於基板背面鍍上一層接地用鋁金屬114。微波輸入116接於 微帶線開迴路諧振器108之一側及接地用的鋁金屬Π4，微波 輸出118接於微帶線開迴路諧振器1〇8另一側及接地用的鋁金 屬 114。 本發明之表面聲波濾波器之鑽石層（或類鑽石層）同時具 有高聲速及優越之震動性，並結合微帶線及交叉指狀電極。使 表面聲波濾波器之工作頻率得以提高。本發明之表面聲波濾波 器亦具有高崩潰電壓、零溫度效應係數及散熱快等優點，如表 1所示。 另外，由於當表面聲波元件在微波頻率領域工作時，其交 叉指狀電極轉換器在微波頻率範圍内又可被視為電磁微波的 集總（lump)元件，所以這些元件同時擔任著兩種不同機制的不 同角色，因此在壓電材料基板(substrate)上，其表面聲波與 材料結構 性能參數 Vs(m/s) K2(°/〇) TCD(l(T6/k) 南聲速 ZnO/AhOa 5500 4.6 43 薄膜 S i O2/ZnO/D i amond 11600 1.2 0 LiNb〇3/Diamond 11900 9.0 -25 微波範圍電磁波之間，將會產生相互關係與交互作用，使工作 頻率、頻寬大幅提高，並使插入損失降低。 參考第2圖，第2圖係顯示依據本發明之實施例具有鑽石 層結構之微波微帶線與表面聲波IDTs交錯耦合組合而成的濾 1241065 波器之頻率響應S參數(Sll，S2l)圖。以網路分析儀量測表面聲 波濾波器之頻率響應S參數(Su，^)，得到一頻寬甚大之濾波 器，其中心頻率提升至1GHZ範圍，插入損失（inserti〇n丨^幻—Mt065 9. Explanation of the invention: [Technical field to which the invention belongs] The present invention relates to a surface acoustic wave filter (Surface Acoustic Wave filter; SAW Filter). In particular, it relates to a method that uses the high speed of sound and superior vibration of diamond (diamond or diamond-like carbon) layers, combined with a Microwave Microstrip line and an interdigital electrode converter (Interdigital Transducers; IDTs). [Previous technology] Not with the high level of informationization of society in recent years, various wireless communication systems have urgent needs and rapid growth. Light, thin, short and small communication systems and The research and development of equipment is a very important issue. Traditional filters are large and heavy, and it is not easy to integrate them. Planar filters can solve these problems. Surface Acoustic Wave (SAW) filters have smaller Size and light weight; however, flat surfaces made of piezoelectric materials such as quartz (Quartz), lithium niobate (LiNbOO, lithium button acid (LiTa〇3), nitride nitride (A1N), zinc oxide (Zn〇), etc. Filters are generally used at frequencies lower than 1 GHz (l // m IDTs). In order to achieve frequencies higher than 1 GHz, high electromechanical coupling coefficients and high-speed surface propagation rates are required. Acoustic filter elements are made of crossed interdigitated electrode converter electrodes on a piezoelectric substrate or a piezoelectric film. When an ID signal at the input end is added with an AC signal, an alternating electric field is generated between the two electrodes. The electric body generates strain due to the inverse piezoelectric effect, which in turn excites surface acoustic waves, transmits them through the piezoelectric material, and transmits the acoustic signals into electrical signals by the positive piezoelectric effect of the IDTs at the output end. Because of the surface acoustic waves The vibration range of the element is only near the surface of the piezoelectric substrate, so a layer of piezoelectric film (such as AIN, ZnO) can also be sputtered on the semiconductor substrate, so that the surface acoustic wave element can be integrated. 1241065 In general, Surface acoustic wave filters are caused by two-way transmission loss, electrode impedance mismatch loss, substrate transmission loss, body wave interference, beam spread loss, parasitic resistance on IDTs, and scattering capacitance of delayed transmission lines. The insertion loss is large; due to the surface acoustic wave filter and the center frequency of the wave device, it depends on the distance between the two electrodes and the material of the piezoelectric element. The phase velocity of the surface acoustic wave (vs = f) is generated when the body is excited. Therefore, if the surface acoustic wave filter is to operate at high frequencies in the GHz range, it is to reduce the distance between the interdigitated electrodes or choose to use the surface acoustic wave. Piezoelectric materials with fast phase speed, if the piezoelectric material of 128. Y-cut LiNb03 is used as the substrate, when working at high frequencies in the GHz range, the IDTs electrode spacing must be less than 丨Only the size can be achieved. Therefore, if the method of improving the characteristics of the surface acoustic wave filter can be achieved according to the following method, it can easily reach the operating frequency above 1GHz, and effectively reduce its insertion loss and increase its bandwidth. Therefore, the present invention aims at the shortcomings of the prior art, and proposes a surface acoustic wave filter with high efficiency, low loss, and high function, which minimizes the volume of the filter and the wave filter: and optimizes its response performance. [Summary of the invention] The object of the present invention is to provide a surface acoustic wave filter, which uses the high sound velocity and superior vibration of the diamond layer or the surface carbon layer, combines the micro-liner strip line and the interdigitated electricity, and converts H 'to make the microwave and Surface acoustic wave interactive system to increase the operating frequency Acoustic frequency λ is providing a kind of surface acoustic wave resonator, which uses the diamond readout and south temperature reading voltage and zero temperature effect, and the microwave microstrip line is coupled with the cross-shaped electrode converter. To reduce insertion loss. The purpose of the conductor is to provide a surface acoustic wave device that uses a process similar to that of semi-i and can be made in the same way as the active component. On the substrate, it is used to form a Monolithic MiCrowave ntegrated Circuit (MMIC) component. It greatly simplifies the volume and area of the element 1241065 'and effectively reduces its manufacturing cost. In order to achieve the above and other objectives, the surface acoustic wave filter, the diamond layer or the carbon layer of the present invention is formed of a microwave microstrip line and an interdigitated electrode converter, and includes at least one substrate on which There is a microwave circuit, and the first layer is misplaced and uploaded, using Longhe: Formation; ^ Stone ^ • Benefit effect, — micro-strip square open-loop resonators and On the alternating current, the microstrip line open-loop device is two opposite at the input end, and the parent cross-shaped electrode is combined. The output end is also two opposite, and the interdigitated electrodes are coupled with each other; -Gamma metal The film is formed on the back surface for grounding purposes. Stomach = The above and other purposes and advantages of the present invention are more easily understood by referring to the following reference drawings and the description of the best practice. [Embodiment] Refer to the first FIG. 1 is a perspective view showing a filter structure in which a microwave microstrip line with a diamond layer structure and a surface acoustic wave IDTs are staggered coupled according to an embodiment of the present invention. Microwave chemistry is performed on a silicon (Si) substrate or a GaAs substrate 102 Vapor deposition (Microwave CVD) / m to 30 // m (preferably a diamond layer (or diamond-like layer) with a thickness of 20) 104, and then formed by radio frequency sputtering (RF Sputter) on the diamond 104 to form 0.5 // m To 3 // m (preferably 1 _) thick oxygen ^ dagger ^ ZnO) or nitride indium (A1N) as the piezoelectric thin film 106, and then re-mineralized in thickness from 100nm to 1000 (A1) 'Sculpted with a microfilm surname to form a 1 // m to 10 // in wide square light-closing microstrip line open-loop resonator 108 and 0 · 1 // m to 5 wide, and a surface acoustic wave with an interval equal to the width The finger electrode converter 11 forms a filter 100 in which the microwave microstrip line and the surface acoustic wave IDTs are staggered. The microstrip line is open-loop spectrally oscillated at the input end, and is coupled by a cross-finger electrode between them. The output end is also The two solid-phase electrodes are lightly closed with interdigitated electrodes. The open-loop gap 112 is used for open-loop 1241065 (open-loop). Then a layer of silicon oxide (si〇2) is deposited as a protective layer. Finally, on the back of the substrate A layer of aluminum metal 114 for grounding is applied. The microwave input 116 is connected to one side of the microstrip open-loop resonator 108 and the aluminum metal 4 for grounding, and the microwave output 118 is connected to the microstrip open-loop resonance. The other side of the device 108 and the aluminum metal 114 for grounding. The diamond layer (or diamond-like layer) of the surface acoustic wave filter of the present invention has high sound speed and excellent vibration at the same time, and combines microstrip lines and interdigitated fingers. The electrode enables the operating frequency of the surface acoustic wave filter to be improved. The surface acoustic wave filter of the present invention also has the advantages of high breakdown voltage, zero temperature effect coefficient, and fast heat dissipation, as shown in Table 1. In addition, when the surface acoustic wave element is in When working in the microwave frequency field, their interdigital electrode converters can also be regarded as lumped components of electromagnetic microwaves in the microwave frequency range. Therefore, these components play different roles of two different mechanisms at the same time. Surface acoustic wave and material structure performance parameters Vs (m / s) K2 (° / 〇) TCD (l (T6 / k) ZnO / AhOa 5500 4.6 43 thin film S i O2 / ZnO / D i amond 11600 1.2 0 LiNb〇3 / Diamond 11900 9.0 -25 There will be mutual relations and interactions between electromagnetic waves in the microwave range, which will greatly increase the operating frequency and bandwidth and reduce insertion loss. Referring to FIG. 2, FIG. 2 is a diagram showing a frequency response S-parameter (Sll, S2l) of a filter 1241065 wave filter composed of a staggered coupling of a microwave microstrip line with a diamond layer structure and a surface acoustic wave IDTs according to an embodiment of the present invention. . The frequency response S parameter (Su, ^) of the surface acoustic wave filter was measured with a network analyzer, and a filter with a very large bandwidth was obtained. The center frequency of the filter was increased to 1 GHz, and the insertion loss (inserti〇n 丨 ^ magic
由原來的一 3· 987dB減少至一2· %2dB，頻寬由原來的 1ΜΗζ(1·6%)擴增為800MHz(80%)如表2所示。表2之SAW filter(16//m 42對IDTs)於壓電材料基板背面無鍍上一層接 地用的鋁金屬，為一微波微帶線與表面聲波IDT 合而成_波器。所以只要將織微帶線與表面^皮錯=、、且 當杳將调度地提昇表面聲波濾、波器 的射頻元件，繼姆«崎質好 所以我們只要將微帶線與表面聲波 的電路設計組合，將可大幅度地提昇表 ^^^田 件，及發展有特殊意義與用途的高附質好的賴元 表2 20.191 dB 插入損失 S2i (dB) ——-- 頻寬 Band Width -3· 987 dB 1 MHz (1.6¾) -2. 962 dB 800 MHz (80°/〇) 損失減少 大幅度增加As shown in Table 2, the original bandwidth is reduced from 3 · 987dB to 2 ·% 2dB, and the bandwidth is amplified from the original 1MΗζ (1.6%) to 800MHz (80%). The SAW filter (16 // m 42 pairs of IDTs) in Table 2 is not plated with a layer of aluminum metal for grounding on the back of the piezoelectric material substrate. It is a microwave microstrip line combined with surface acoustic wave IDT. So as long as weaving the microstrip line and the surface ^ skin error =, and when the radio frequency components of the surface acoustic wave filter and wave device will be promoted in a scheduled manner, the quality is good, so we only need to connect the microstrip line and the surface acoustic wave circuit The design combination will greatly enhance the table ^^^ field, and develop a high-quality lyon table with special meaning and use. 2 20.191 dB insertion loss S2i (dB) ——-- Band Width- 3.987 dB 1 MHz (1.6¾) -2. 962 dB 800 MHz (80 ° / 〇) Loss reduction significantly increased
No. 3光罩之電路 一中心 Central Freq. 製作於LiNb〇3基板 SAW filter 61.00 MHz (16//m 42 對 IDTs) Microwave & 1.064 GHz SAW filter 比較 提高至 GHz範圍 反射損失 Sn (dB)No. 3 photomask circuit One center Central Freq. Made on LiNb〇3 substrate SAW filter 61.00 MHz (16 // m 42 pairs of IDTs) Microwave & 1.064 GHz SAW filter Comparison Increase to GHz range Reflection loss Sn (dB)
25. 212 dB 損失減少 124ΐ〇ύ5 目前可用來製作表面聲波的壓電薄膜，主要有氧化 (ΖηΟ)、氮化鋁（Α1Ν)等壓電薄膜及鑽石或類鑽碳（DLC)薄 膜上成長氧化辞（Si〇2/ZnO /Diamond/Si)壓電薄膜。氧化辞 (ZnO)和氮化鋁（A1N)壓電薄膜的聲速為目前通訊產業常用 壓電晶體材料平均聲速的1· 5倍左右，鑽石或類鑽;g炭（DLC) 薄膜上成長氧化辞壓電薄膜則高達3倍左右。以三種不同頻 的產品（ 900MHz單頻手機、1800MHz/l900MHz雙頻手機、' 2400MHz衛星系統及3G手機）為例，製作這三種頻率表面聲 波濾波器所要求的IDTs線寬技術分別列於表3。可知品質絕 佳的鑽石結構配合控制適當的氧化鋅薄膜厚度，可輕易g^到 上列的濾波頻率，如此不僅大幅度地減輕了表面聲波元件對 術設備的需求，也為表面聲波元件迫切高頻化的發展趨勢奠定 了基礎。以目前國外最先進的0.13#m線寬技術為例，、用 Si〇2/ZnO/Diamond/Si壓電薄膜，可產生頻率高達2〇GHz以 的表面聲波濾波器。 表325. 212 dB loss reduction 124ΐ〇ύ5 At present, piezoelectric films that can be used to make surface acoustic waves are mainly piezoelectric films such as oxide (ZηΟ), aluminum nitride (Α1Ν), and diamond or diamond-like carbon (DLC) films. (Si〇2 / ZnO / Diamond / Si) piezoelectric thin film. The sound velocity of oxide films (ZnO) and aluminum nitride (A1N) piezoelectric films is about 1.5 times the average sound velocity of piezoelectric crystal materials commonly used in the communication industry. Diamond or diamond-like materials; oxide films growing on carbon (DLC) films. The piezoelectric film is about three times as high. Taking three different frequency products (900MHz single-frequency mobile phone, 1800MHz / l900MHz dual-frequency mobile phone, '2400MHz satellite system, and 3G mobile phone) as examples, the IDTs linewidth technologies required to make these three-frequency surface acoustic wave filters are listed in Table 3 respectively. . It can be seen that the diamond structure with excellent quality and the appropriate thickness of the zinc oxide film can easily be adjusted to the filtering frequency listed above. This not only greatly reduces the need for surface acoustic wave components for surgical equipment, but also makes the surface acoustic wave components extremely high. The development trend of frequency has laid the foundation. Taking the most advanced 0.13 # m line width technology abroad as an example, the use of Si〇2 / ZnO / Diamond / Si piezoelectric film can generate surface acoustic wave filters with frequencies up to 20 GHz. table 3
藉由以上較佳之具體實施例之詳述，係希望能更加清 述本創作之特徵與精神，而並非以上述所揭露的較 : 來對本發明之範圍加以限制。相反的，其目的是希望^涵 種改變及具相等性的安排於本發明所欲申請之專利範圍内。 11 1241065 ^ 【圖式簡單說明】 第1圖係顯示依據本發明之實施例具有鑽石層結構之微波微帶 線與表面聲波IDTs交錯耦合之濾波器構造透視圖。 第2圖係顯示依據本發明之實施例具有鑽石層結構之微波微 帶線與表面聲波IDTs交錯耦合之濾波器之頻率響應S參 數(Su，S21)圖。 【主要元件符號說明】With the detailed description of the above-mentioned preferred embodiments, it is hoped that the characteristics and spirit of the present invention can be more clearly described, rather than limiting the scope of the present invention with the above disclosure. On the contrary, the purpose is to hope that various changes and equivalent arrangements are within the scope of the patents to be applied for in the present invention. 11 1241065 ^ [Schematic description] Figure 1 is a perspective view showing a filter structure in which a microwave microstrip line with a diamond layer structure and a surface acoustic wave IDTs are staggered coupled according to an embodiment of the present invention. Fig. 2 is a graph showing the frequency response S-parameter (Su, S21) of a filter in which a microwave microstrip line with a diamond layer structure and a surface acoustic wave IDTs are staggered coupled according to an embodiment of the present invention. [Description of main component symbols]
100微波微帶線與表面聲波IDTs交錯耦合之濾波器 102矽基板或GaAs基板 104鑽石層（或類鑽石層） 106壓電薄膜 108微帶線開迴路諧振器 110交叉指狀電極轉換器 112開迴路缺口 114接地用的鋁金屬 116微波輸入 118微波輸出100 Microwave microstrip line and surface acoustic wave IDTs staggered coupling filter 102 Silicon substrate or GaAs substrate 104 Diamond layer (or diamond-like layer) 106 Piezo film 108 Microstrip open-loop resonator 110 Cross-finger electrode converter 112 Open Loop notch 114 Aluminum metal for grounding 116 Microwave input 118 Microwave output
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