JP2008078981A5 - - Google Patents
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- JP2008078981A5 JP2008078981A5 JP2006255588A JP2006255588A JP2008078981A5 JP 2008078981 A5 JP2008078981 A5 JP 2008078981A5 JP 2006255588 A JP2006255588 A JP 2006255588A JP 2006255588 A JP2006255588 A JP 2006255588A JP 2008078981 A5 JP2008078981 A5 JP 2008078981A5
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- 230000001681 protective Effects 0.000 claims description 27
- 239000000758 substrate Substances 0.000 claims description 18
- 229910000838 Al alloy Inorganic materials 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminum Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- GQYHUHYESMUTHG-UHFFFAOYSA-N Lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 claims description 3
- 230000001568 sexual Effects 0.000 claims 1
- 239000010408 film Substances 0.000 description 72
- 238000010897 surface acoustic wave method Methods 0.000 description 25
- 230000000694 effects Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 230000001629 suppression Effects 0.000 description 4
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000001312 dry etching Methods 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N Silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 230000001808 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- XCCANNJCMHMXBZ-UHFFFAOYSA-N hydroxyiminosilicon Chemical compound ON=[Si] XCCANNJCMHMXBZ-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Description
本発明は、共振子や帯域フィルタとして用いられる弾性波共振器およびこれを用いた弾性波フィルタ、アンテナ共用器に関するものである。 The present invention, elastic wave resonators and elastic wave filter using the same to be used as a resonator or a band-pass filter, it relates to an antenna duplexer.
従来のこの種の弾性波共振器としては、ＬｉＮｂＯ3基板上にＳｉＯ2の薄膜層を形成するとともに、前記ＬｉＮｂＯ3基板の回転Ｙ板のカット角度を−１０度〜＋３０度とし、前記薄膜層の膜厚寸法をＨ、前記弾性波の動作中心周波数の波長をλとしたときに、規格化電極膜厚（Ｈ／λ）の値を０．１１５から０．３１としていた。 Conventional elastic wave resonator of this type, to form a thin layer of SiO 2 on the LiNbO 3 substrate, the cut angle of the rotated Y plate of the LiNbO 3 substrate and -10 degrees to + 30 degrees, the thin film the thickness dimensions of the layers H, the wavelength of the operating center frequency of the bullet resistant wave when the lambda, and the value of the normalized electrode thickness (H / λ) from 0.115 not 0.31.
これにより、Ｑ値が高く、電気機械結合係数ｋ２が大きく、かつ周波数温度特性の優れた弾性波共振器を得ていた。 Accordingly, Q value is high, the electromechanical coupling coefficient k2 is large and had gained an excellent elastic wave resonator frequency temperature characteristic.
また、ＬｉＮｂＯ3基板においては、カット角が６４°や４１°の場合には、ロスやスプリアスの観点から、規格化電極膜厚は、約４％、もしくは２．５％以上７．５％以下が適しているとされている。 In the case of a LiNbO 3 substrate, when the cut angle is 64 ° or 41 °, the normalized electrode film thickness is about 4%, or 2.5% to 7.5% from the viewpoint of loss and spurious. Is considered suitable.
なお、この出願の発明に関する先行技術文献情報としては、例えば、特許文献１〜３が知られている。
上記した従来の弾性波共振器においては、櫛型電極の膜厚が考慮されていないため、スプリアスを抑えて、かつ、Ｑ値が高い櫛型電極の膜厚を備えた弾性波共振器を得ることができないという課題を有していた。 In the conventional elastic wave resonator described above, since the film thickness of the interdigital electrodes is not taken into account, by suppressing spurious, and the elastic wave resonator having a film thickness of high Q comb electrodes Had the problem of not being able to get.
本発明は、上記従来の課題を解決するもので、スプリアスを抑えて、かつ、Ｑ値が高い櫛型電極の膜厚を備えた弾性波共振器を得ることを目的とするものである。 The present invention is intended to solve the conventional problems described above, by suppressing spurious, and it is an object of the Q value is obtained with high comb electrode having a thickness of the elastic wave resonator having a.
上記目的を達成するために本発明は、以下の構成を有するものである。 In order to achieve the above object, the present invention has the following configuration.
本発明の請求項１に記載の発明は、ニオブ酸リチウムからなる基板と、この基板の上面に設けられアルミニウムまたはアルミニウム合金で構成された少なくとも１つの櫛型電極と、この櫛型電極を覆うとともに表面に凹凸形状を有する保護膜とを備え、前記基板の回転Ｙ板のカット角を０〜＋２５度とし、かつ、前記櫛型電極の膜厚をｈ、波長をλとしたときに、規格化電極膜厚（ｈ／λ）を７．８〜９．８％としたもので、この構成によれば、Ｑ値が高く、さらに減衰量も大きい弾性波共振器が得られるという作用効果が得られる。 According to the first aspect of the present invention, there is provided a substrate made of lithium niobate, at least one comb electrode formed on the upper surface of the substrate and made of aluminum or an aluminum alloy, and covering the comb electrode And a protective film having a concavo-convex shape on the surface, standardized when the cut angle of the rotating Y plate of the substrate is 0 to +25 degrees, the film thickness of the comb-shaped electrode is h, and the wavelength is λ in which the electrode film thickness (h / λ) set to 7.8 to 9.8%, according to this configuration, Q value is high, the effect that further attenuation is large elastic wave resonator is obtained can get.
本発明の請求項２に記載の発明は、特に、規格化電極膜厚を８．５〜９．０％としたもので、この構成によれば、Ｑ値がより高く、さらに減衰量もより大きい弾性波共振器が得られるという作用効果が得られる。また、本発明の請求項２に記載の発明は、共振周波数よりも低周波側のスプリアスを抑制するように、前記保護膜の凹凸形状を形成したものである。 The invention according to claim 2 of the present invention is, in particular, a standardized electrode film thickness of 8.5 to 9.0%. According to this configuration, the Q value is higher and the attenuation is further increased. large elastic wave resonator is obtained effect that is obtained. According to a second aspect of the present invention, the protective film has an uneven shape so as to suppress spurious frequencies on the lower frequency side than the resonance frequency.
本発明の請求項４に記載の発明は、特に、保護膜の凹凸形状の１ピッチあたりのピッチ幅をＬ、前記保護膜の凹凸形状の１ピッチあたりの凸部の幅をＬ１、凹部の幅をＬ２、櫛型電極の１ピッチあたりのピッチ幅をｐ、前記櫛型電極を構成する電極指１本あたりの幅をｐ１、前記電極指間の幅をｐ２としたとき、Ｌ１≦ｐ１かつＬ２≧ｐ２（ただし、ｐ１＋ｐ２＝ｐ、Ｌ１＋Ｌ２＝Ｌの関係を満たす）であるもので、この構成によれば、スプリアスの抑制、挿入損失の低減をすることができるという作用効果が得られる。 In the invention according to claim 4 of the present invention, in particular, the pitch width per pitch of the concavo-convex shape of the protective film is L, the width of the convex portion per pitch of the concavo-convex shape of the protective film is L1, and the width of the concave portion Where L1 is a pitch width per pitch of the comb-shaped electrode, p1 is a width per electrode finger constituting the comb-shaped electrode, and p2 is a width between the electrode fingers. ≧ p2 (however, the relationship of p1 + p2 = p and L1 + L2 = L is satisfied). According to this configuration, it is possible to obtain an operational effect that spurious can be suppressed and insertion loss can be reduced.
本発明の請求項５に記載の発明は、特に、請求項１記載の弾性波共振器を直並列に梯子型に接続した弾性波フィルタであって、少なくとも１つの前記弾性波共振器の規格化電極膜厚を７．８〜９．８％とした弾性波フィルタであるもので、この構成によれば、Ｑ値が高く、さらに減衰量も大きい弾性波フィルタが得られるという作用効果が得られる。 The invention described in claim 5 of the present invention, particularly, a elastic wave filter connected in a ladder-type elastic wave resonator according to claim 1, wherein the series-parallel, at least one of the bullet resistant wave resonator those which are elastic wave filter a normalized electrode thickness set to 7.8 to 9.8%, according to this arrangement, that the Q value is high, more attenuation is large elastic wave filter obtained The effect is obtained.
本発明の請求項６に記載の発明は、特に、請求項１記載の弾性波共振器を複数、弾性波の伝播方向に沿って位置させ、かつ前記複数の弾性波共振器を構成する櫛型電極同士を近接させ、少なくとも１つの前記弾性波共振器の規格化電極膜厚の値を７．８〜９．８％とした弾性波フィルタであるもので、この構成によれば、Ｑ値が高く、さらに減衰量も大きい弾性波フィルタが得られるという作用効果が得られる。 The invention described in claim 6 of the present invention, in particular, constituting a plurality of elastic wave resonator according to claim 1, it is positioned along the propagation direction of the elastic wave, and a plurality of elastic wave resonators it is approximated to comb electrodes each other to, those wherein at least one elastic wave filter values of normalized electrode thickness set to 7.8 to 9.8% of the bullets of wave resonator, this configuration if, Q value is high, further attenuation is large elastic wave filter is obtained effect that is obtained.
本発明の請求項７に記載の発明は、特に、請求項４または５記載の弾性波フィルタを、信号の入力側および出力側に配置したアンテナ共用器であるもので、この構成によれば、Ｑ値が高く、減衰量も大きいアンテナ共用器が得られるという作用効果が得られる。 The invention according to claim 7 of the present invention, in particular, the elastic wave filter according to claim 4 or 5, wherein one is an antenna duplexer which is arranged at the input side and output side of the signal, according to this configuration Thus, an effect of obtaining an antenna duplexer having a high Q value and a large attenuation can be obtained.
以上のように本発明の弾性波共振器は、基板の回転Ｙ板のカット角を０〜＋２５度とし、かつ、櫛型電極の膜厚をｈ、波長をλとしたときに、規格化電極膜厚（ｈ／λ）を７．８〜９．８％としているため、Ｑ値が高く、さらに減衰量も大きい弾性波共振器が得られる。そして、保護膜の表面を凹凸形状としているため、スプリアスを抑えた弾性波共振器を実現することができるという優れた効果を奏するものである。 Elastic wave resonator of the present invention as described above, the cut angle of the rotation Y plate of the substrate and 0 to + 25 degrees, and the thickness of the comb electrode h, when the wavelength is lambda, normalized since you are the electrode film thickness (h / λ) 7.8~9.8%, Q value is high, to obtain more attenuation is large elastic wave resonator. Then, since the surface of the protective film is an uneven shape, in which an excellent effect of being able to realize the elastic wave resonator with reduced spurious.
図１は本発明の一実施の形態における弾性表面波共振器の主要部の上面図、図２は図１のＡ−Ａ線断面図であり、ニオブ酸リチウムからなる基板１と、この基板１の上面に設けられ、アルミニウムまたはアルミニウム合金で構成された櫛型電極２および反射器電極３と、この櫛型電極２および反射器電極３を覆うとともに表面に凹凸形状を有する保護膜４とを備えている。 FIG. 1 is a top view of a main part of a surface acoustic wave resonator according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA of FIG. The comb-shaped electrode 2 and the reflector electrode 3 made of aluminum or an aluminum alloy, and the protective film 4 covering the comb-shaped electrode 2 and the reflector electrode 3 and having an uneven shape on the surface are provided. ing.
また、前記基板１の回転Ｙ板のカット角を０〜＋２５度とし、かつ、前記櫛型電極２の膜厚をｈ、波長をλとしたときに、規格化電極厚ｈ／λの値を７．８〜９．８％としている。 Further, when the cut angle of the rotating Y plate of the substrate 1 is 0 to +25 degrees, the film thickness of the comb-shaped electrode 2 is h, and the wavelength is λ, the value of the normalized electrode thickness h / λ is 7.8 to 9.8%.
上記構成において、前記基板１は、Ｘ軸周りにＺ軸方向へ数度回転させたＹ板から切り出したニオブ酸リチウムからなるもので、その回転の角度が０〜＋２５度となっている。 In the above configuration, the substrate 1 is made of lithium niobate cut from a Y plate rotated several degrees around the X axis in the Z axis direction, and the rotation angle is 0 to +25 degrees.
前記櫛型電極２および反射器電極３は、基板１の上面にそれぞれ一対形成され、アルミニウム（以下、「Ａｌ」とする。）またはＡｌ合金からなるものである。 The comb electrode 2 and the reflector electrode 3 are formed in pairs on the upper surface of the substrate 1 and are made of aluminum (hereinafter referred to as “Al”) or an Al alloy.
前記保護膜４は、好ましくは二酸化シリコン（以下、「ＳｉＯ2」とする。）からなる
もので、図３に示すように、その上面は凹凸形状を備えている。保護膜４の凸部分４ａは、基板１の上面の櫛型電極２、反射器電極３を有する部分の上方に備わっている。また、保護膜４の凹部分４ｂは、凸部分４ａ間の櫛型電極２、反射器電極３が基板１の上面に存在しない部分およびその近傍に備わっている。
The protective film 4 is preferably made of silicon dioxide (hereinafter referred to as “SiO 2 ”), and its upper surface has an uneven shape as shown in FIG. The convex portion 4 a of the protective film 4 is provided above the portion having the comb electrode 2 and the reflector electrode 3 on the upper surface of the substrate 1. Further, the concave portion 4 b of the protective film 4 is provided in and near the portion where the comb-shaped electrode 2 and the reflector electrode 3 between the convex portions 4 a do not exist on the upper surface of the substrate 1.
ここで、図３において、保護膜４の凸部分４ａ、凹部分４ｂ各々１つを１ピッチとし、この１ピッチあたりのピッチ幅をＬとし、保護膜４の凸部分４ａの幅をＬ１とし、保護膜４の凹部分４ｂの幅をＬ２（Ｌ＝Ｌ１＋Ｌ２が成り立つこと）とする。また、１つの櫛型電極２の電極指２ａおよび一方が隣り合う電極指２ａの存在する部分までを櫛型電極２の１ピッチ幅ｐとする。さらに、電極指２ａの１本あたりの幅をｐ１とし、隣り合う電極指間の幅をｐ２（ｐ＝ｐ１＋ｐ２が成り立つこと）とする。 Here, in FIG. 3, each of the convex portion 4a and the concave portion 4b of the protective film 4 is one pitch, the pitch width per pitch is L, and the width of the convex portion 4a of the protective film 4 is L1, The width of the concave portion 4b of the protective film 4 is L2 (L = L1 + L2 holds). Further, the pitch between the electrode fingers 2a of one comb-shaped electrode 2 and the portion where one electrode finger 2a is adjacent is defined as one pitch width p of the comb-shaped electrode 2. Furthermore, the width per electrode finger 2a is p1, and the width between adjacent electrode fingers is p2 (p = p1 + p2 holds).
また、保護膜４と接している基板１の表面から保護膜４の凹部分４ｂまでの高さである保護膜４の膜厚をｔとし、櫛型電極２の膜厚をｈとする。なお、図３においては、櫛型電極２の電極子２ａを２本のみ示している。 The film thickness of the protective film 4 that is the height from the surface of the substrate 1 in contact with the protective film 4 to the concave portion 4b of the protective film 4 is t, and the film thickness of the comb-shaped electrode 2 is h. In FIG. 3, only two electrode elements 2a of the comb-shaped electrode 2 are shown.
上記の場合において、Ｌ１≦ｐ１かつＬ２≧ｐ２の関係を満たし、弾性表面波の動作中心周波数の波長をλ（＝２×ｐ）としたとき、規格化電極膜厚ｈ／λは、７．８〜９．８％の範囲内にある。 In the above case, when the relationship of L1 ≦ p1 and L2 ≧ p2 is satisfied and the wavelength of the operation center frequency of the surface acoustic wave is λ (= 2 × p), the normalized electrode film thickness h / λ is 7. It is in the range of 8 to 9.8%.
次に、本発明の一実施の形態における弾性表面波共振器の製造方法について説明する。 Next, a method for manufacturing a surface acoustic wave resonator according to an embodiment of the present invention will be described.
図４は本発明の一実施の形態における弾性表面波共振器の製造方法を説明する断面図である。 FIG. 4 is a cross-sectional view illustrating a method for manufacturing a surface acoustic wave resonator according to an embodiment of the present invention.
まず、図４（ａ）に示すように、基板１の上面にＡｌまたはＡｌ合金を蒸着またはスパッタ等の方法により櫛型電極２および反射器電極３となる電極膜３ａを成膜する。 First, as shown in FIG. 4A, an electrode film 3a to be the comb electrode 2 and the reflector electrode 3 is formed on the upper surface of the substrate 1 by vapor deposition or sputtering.
次に、図４（ｂ）に示すように、電極膜３ａの上面にレジスト膜５を形成する。 Next, as shown in FIG. 4B, a resist film 5 is formed on the upper surface of the electrode film 3a.
次に、図４（ｃ）に示すように、電極膜３ａを櫛型電極２や反射器電極３等が所望の形状となるように露光・現像技術等を用いてレジスト膜５を加工する。 Next, as shown in FIG. 4C, the resist film 5 is processed using an exposure / development technique or the like so that the comb-shaped electrode 2, the reflector electrode 3 and the like have a desired shape.
次に、図４（ｄ）に示すように、ドライエッチング技術等を用いてレジスト膜５を除去する。 Next, as shown in FIG. 4D, the resist film 5 is removed using a dry etching technique or the like.
次に、図４（ｅ）に示すように、電極膜３ａを覆うようにＳｉＯ2を蒸着またはスパッタ等の方法により、保護膜４を形成する。 Next, as shown in FIG. 4E, the protective film 4 is formed by a method such as vapor deposition or sputtering of SiO 2 so as to cover the electrode film 3a.
次に、図４（ｆ）に示すように、保護膜４の表面にレジスト膜６を形成する。 Next, as shown in FIG. 4F, a resist film 6 is formed on the surface of the protective film 4.
次に、図４（ｇ）に示すように、露光、現像技術等を用いてレジスト膜６を所望の形状に加工する。 Next, as shown in FIG. 4G, the resist film 6 is processed into a desired shape using exposure, development techniques, and the like.
最後に、図４（ｈ）に示すように、ドライエッチング技術等を用いて、電気信号取出しのためのパッド（図示せず）等の保護膜４が不要な部分の保護膜４を取り除き、その後レジスト膜６を除去する。 Finally, as shown in FIG. 4 (h), by using a dry etching technique or the like, a portion of the protective film 4 that does not require the protective film 4 such as a pad (not shown) for extracting an electric signal is removed, and thereafter The resist film 6 is removed.
図５は、本発明の一実施の形態の弾性表面波共振器における規格化電極膜厚ｈ／λと共振点のＱ値（規格化Ｑｓ）との関係を示す図、図６は、同弾性表面波共振器における規格化電極膜厚ｈ／λと反共振点のＱ値（規格化Ｑｐ）との関係を示す図、図７は、同弾性表面波共振器における通過特性を示す図、図８は、同弾性表面波共振器における規格化電極膜厚と減衰量との関係を示す図である。ここで、規格化Ｑｓ、規格化Ｑｐは、従来使用されていた規格化電極膜厚が５．８％のときのＱｓ、Ｑｐで規格化した値である。 FIG. 5 is a diagram showing the relationship between the normalized electrode film thickness h / λ and the Q value (normalized Qs) of the resonance point in the surface acoustic wave resonator according to the embodiment of the present invention, and FIG. FIG. 7 is a diagram showing the relationship between the normalized electrode film thickness h / λ and the antiresonance point Q value (standardized Qp) in the surface acoustic wave resonator, and FIG. 7 is a diagram showing the pass characteristics in the surface acoustic wave resonator. FIG. 8 is a diagram showing the relationship between the normalized electrode film thickness and the attenuation in the surface acoustic wave resonator. Here, standardized Qs and standardized Qp are values normalized by Qs and Qp when the standardized electrode film thickness that has been conventionally used is 5.8%.
このとき、Ｌ１≦ｐ１かつＬ２≧ｐ２の関係を満たし、保護膜４としては、酸化ケイ素を用いており、その膜厚をｔと波長λとの関係式である保護膜４の規格化膜厚ｔ／λを２０％としたものを使用した。 At this time, the relationship of L1 ≦ p1 and L2 ≧ p2 is satisfied, and silicon oxide is used as the protective film 4, and the normalized film thickness of the protective film 4 is a relational expression between t and wavelength λ. What used t / (lambda) as 20% was used.
図５〜図６から明らかなように、規格化電極膜厚ｈ／λを７．８〜９．８％とすると、規格化Ｑｓ、規格化Ｑｐは１．２倍以上になっており、Ｑ値が高い弾性表面波共振器が得られることがわかる。特に、規格化電極膜厚ｈ／λが８．５〜９．０％のとき、Ｑ値が最も良くなる。 As apparent from FIGS. 5 to 6, when the normalized electrode film thickness h / λ is 7.8 to 9.8%, the normalized Qs and the normalized Qp are 1.2 times or more. It can be seen that a surface acoustic wave resonator having a high value can be obtained. In particular, when the normalized electrode film thickness h / λ is 8.5 to 9.0%, the Q value is the best.
さらに、図７に、本発明における弾性表面波共振器の通過特性を示す。図７（ａ）は、規格化電極膜厚が８．７％のときの通過特性であり、図７（ｂ）は規格化電極膜厚が５．８％のときの通過特性である。図７から明らかなように、規格化電極膜厚ｈ／λを７．８〜９．８％の範囲とすることにより、減衰量は規格化電極膜厚が５．８％のときに比べて約６ｄＢ大きくなる（周波数がずれているのは、規格化電極膜厚が異なるためであり、対数や交差幅等の弾性表面波共振器の構成としては同一である。）。また、図８に減衰量の規格化膜厚依存性を示す。図８より、規格化電極膜厚ｈ／λを７．８〜９．８％の範囲とすることにより、減衰量は規格化電極膜厚が５．８％のときに比べて約５ｄＢ以上大きくなる。特に、規格化電極膜厚ｈ／λが８．５〜９．０％のとき、減衰量が最も良くなる。 Further, FIG. 7 shows the pass characteristics of the surface acoustic wave resonator according to the present invention. FIG. 7A shows pass characteristics when the normalized electrode film thickness is 8.7%, and FIG. 7B shows pass characteristics when the normalized electrode film thickness is 5.8%. As can be seen from FIG. 7, by setting the normalized electrode film thickness h / λ in the range of 7.8 to 9.8%, the attenuation is smaller than that when the normalized electrode film thickness is 5.8%. The frequency is shifted because the normalized electrode film thickness is different, and the configuration of the surface acoustic wave resonator such as logarithm and cross width is the same. FIG. 8 shows the dependence of attenuation on the normalized film thickness. As shown in FIG. 8, by setting the normalized electrode film thickness h / λ in the range of 7.8 to 9.8%, the attenuation is larger by about 5 dB or more than when the normalized electrode film thickness is 5.8%. Become. In particular, when the normalized electrode film thickness h / λ is 8.5 to 9.0%, the attenuation amount is the best.
また、図９に本発明の弾性表面波共振器をラダー型に接続したフィルタ特性を示す。ラダー型フィルタとしては、直列共振器を１段、並列共振器を１段とした構成である。図９（ａ）はフィルタ特性、図９（ｂ）は縦軸の拡大図である。また、図９において、９０１は並列共振器の規格化電極膜厚が７．８％、直列共振器の規格化電極膜厚が８．３％のときのフィルタ特性であり、９０２は並列共振器の規格化電極膜厚が５．８％、直列共振器の規格化電極膜厚が６．２％のときのフィルタ特性である。図９から明らかなように、規格化電極膜厚ｈ／λを７．８〜９．８％の範囲とすることにより、挿入損失が０．１ｄＢ改善されている（周波数がずれているのは、規格化電極膜厚が異なるためであり、対数や交差幅等の弾性表面波共振器の構成や配置としては同一である。）。 FIG. 9 shows filter characteristics in which the surface acoustic wave resonator of the present invention is connected in a ladder shape. The ladder filter has a configuration in which one series of series resonators and one stage of parallel resonators. FIG. 9A is a filter characteristic, and FIG. 9B is an enlarged view of the vertical axis. In FIG. 9, reference numeral 901 denotes filter characteristics when the normalized resonator film thickness of the parallel resonator is 7.8% and the normalized resonator film thickness of the series resonator is 8.3%, and 902 is the parallel resonator. This is a filter characteristic when the normalized electrode film thickness is 5.8% and the normalized electrode film thickness of the series resonator is 6.2%. As is apparent from FIG. 9, the insertion loss is improved by 0.1 dB by setting the normalized electrode film thickness h / λ in the range of 7.8 to 9.8% (the frequency is shifted. This is because the normalized electrode film thickness is different, and the configuration and arrangement of the surface acoustic wave resonators such as logarithm and cross width are the same.
なお、本実施の形態においては、保護膜として酸化ケイ素を用いているが、これに限るものではなく、窒化ケイ素や酸窒化ケイ素など他の材料を組み合わせてもかまわない。 In this embodiment, silicon oxide is used as the protective film, but the present invention is not limited to this, and other materials such as silicon nitride and silicon oxynitride may be combined.
また、アンテナ共用器を構成する場合には、送信側フィルタと受信側フィルタとで電極指のピッチが異なるため、規格化電極膜厚が異なる。この場合には、送信側フィルタと受信側フィルタとで電極膜厚を変えることにより、さらに最適な構成とすることができる。 Further, when the antenna duplexer is configured, the normalized electrode film thickness is different because the pitch of the electrode fingers is different between the transmission side filter and the reception side filter. In this case, a more optimal configuration can be obtained by changing the electrode film thickness between the transmission side filter and the reception side filter.
さらに、フィルタを構成する場合には、直列共振器と並列共振器で電極指のピッチが異なるため、規格化電極膜厚が異なる。この場合には、直列共振器と並列共振器とで電極膜厚を変えることにより、さらに最適な構成とすることができる。 Further, when the filter is configured, the normalized electrode film thickness is different because the pitch of the electrode fingers is different between the series resonator and the parallel resonator. In this case, a more optimal configuration can be obtained by changing the electrode film thickness between the series resonator and the parallel resonator.
本発明に係る弾性表面波共振器は、スプリアスを抑え、かつ、Ｑ値が高く、さらに減衰量も大きいという効果を有するものであり、共振子や帯域フィルタとして用いられる弾性表面波共振器およびこれを用いた弾性表面波フィルタ、アンテナ共用器等において有用となるものである。 The surface acoustic wave resonator according to the present invention has an effect of suppressing spurious and having a high Q value and a large amount of attenuation, and a surface acoustic wave resonator used as a resonator and a bandpass filter. This is useful in a surface acoustic wave filter using an antenna, an antenna duplexer, and the like.
１ 基板
２ 櫛型電極
２ａ 電極指
４ 保護膜
DESCRIPTION OF SYMBOLS 1 Substrate 2 Comb electrode 2a Electrode finger 4 Protective film
Claims (7)
Ｌ１≦ｐ１かつＬ２≧ｐ２
（ただし、ｐ１＋ｐ２＝ｐ、Ｌ１＋Ｌ２＝Ｌの関係を満たす）である請求項１に記載の弾性波共振器。 The pitch width per pitch of the concavo-convex shape of the protective film is L, the width of the convex portion per pitch of the concavo-convex shape of the protective film is L1, the width of the concave portion is L2, and the pitch width per pitch of the comb-shaped electrode is p, when the width per electrode finger constituting the comb electrode is p1, and the width between the electrode fingers is p2,
L1 ≦ p1 and L2 ≧ p2
(However, to satisfy the relationship of p1 + p2 = p, L1 + L2 = L) elastic wave resonator according to claim 1 is.
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| JP2006255588A JP4544227B2 (en) | 2006-09-21 | 2006-09-21 | Elastic wave resonator, elastic wave filter and antenna duplexer using the same |
| EP07714184A EP1971026A1 (en) | 2006-02-16 | 2007-02-14 | Surface acoustic wave device, surface acoustic wave filter employing same and antenna duplexer, and electronic apparatus employing same |
| PCT/JP2007/052631 WO2007094368A1 (en) | 2006-02-16 | 2007-02-14 | Surface acoustic wave device, surface acoustic wave filter employing same and antenna duplexer, and electronic apparatus employing same |
| KR1020107001186A KR100979952B1 (en) | 2006-02-16 | 2007-02-14 | Surface acoustic wave device, surface acoustic wave filter employing same and antenna duplexer, and electronic apparatus employing same |
| US12/279,631 US8035460B2 (en) | 2006-02-16 | 2007-02-14 | Surface acoustic wave device, surface acoustic wave filter and antenna duplexer using the same, and electronic equipment using the same |
| CN2007800048973A CN101379700B (en) | 2006-02-16 | 2007-02-14 | Surface acoustic wave device, and manufacturing method thereof |
| KR1020087014499A KR100961481B1 (en) | 2006-02-16 | 2007-02-14 | Surface acoustic wave device, surface acoustic wave filter employing same and antenna duplexer, and electronic apparatus employing same |
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| WO2011102128A1 (en) | 2010-02-22 | 2011-08-25 | パナソニック株式会社 | Antenna sharing device |
| JP2011182220A (en) | 2010-03-02 | 2011-09-15 | Panasonic Corp | Acoustic wave resonator and vertically coupled double mode filter using the same, as well as ladder filter |
| JP5976096B2 (en) * | 2012-03-02 | 2016-08-23 | 太陽誘電株式会社 | Elastic wave filter |
| WO2015198905A1 (en) * | 2014-06-27 | 2015-12-30 | 株式会社村田製作所 | Elastic wave device |
| WO2016013659A1 (en) * | 2014-07-25 | 2016-01-28 | 株式会社村田製作所 | Bandpass filter and filter module |
| CN113162580A (en) * | 2021-04-30 | 2021-07-23 | 江苏卓胜微电子股份有限公司 | Method for manufacturing acoustic surface wave resonator |
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| JPH1084245A (en) * | 1996-09-10 | 1998-03-31 | Hitachi Ltd | Surface acoustic wave element |
| JPH1188100A (en) * | 1997-09-03 | 1999-03-30 | Toyo Commun Equip Co Ltd | Surface acoustic wave device |
| JP4109877B2 (en) * | 2001-03-04 | 2008-07-02 | 和彦 山之内 | Surface acoustic wave functional element |
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