JPH04294625A - Surface acoustic wave element - Google Patents
Surface acoustic wave elementInfo
- Publication number
- JPH04294625A JPH04294625A JP6030191A JP6030191A JPH04294625A JP H04294625 A JPH04294625 A JP H04294625A JP 6030191 A JP6030191 A JP 6030191A JP 6030191 A JP6030191 A JP 6030191A JP H04294625 A JPH04294625 A JP H04294625A
- Authority
- JP
- Japan
- Prior art keywords
- acoustic wave
- electrode
- surface acoustic
- protective film
- wave device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010897 surface acoustic wave method Methods 0.000 title claims description 31
- 230000001681 protective effect Effects 0.000 claims description 20
- 239000000758 substrate Substances 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 16
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 13
- 229910052804 chromium Inorganic materials 0.000 claims description 13
- 239000011651 chromium Substances 0.000 claims description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 7
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 239000010936 titanium Substances 0.000 claims description 3
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052697 platinum Inorganic materials 0.000 claims description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 2
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 2
- 235000012239 silicon dioxide Nutrition 0.000 claims description 2
- 239000000377 silicon dioxide Substances 0.000 claims description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 2
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 claims description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 2
- 229910052721 tungsten Inorganic materials 0.000 claims description 2
- 239000010937 tungsten Substances 0.000 claims description 2
- 239000003989 dielectric material Substances 0.000 claims 1
- 239000010408 film Substances 0.000 description 30
- 229910052782 aluminium Inorganic materials 0.000 description 14
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 14
- 238000007740 vapor deposition Methods 0.000 description 7
- 238000005260 corrosion Methods 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 description 1
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- RIUWBIIVUYSTCN-UHFFFAOYSA-N trilithium borate Chemical compound [Li+].[Li+].[Li+].[O-]B([O-])[O-] RIUWBIIVUYSTCN-UHFFFAOYSA-N 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【０００１】0001
【産業上の利用分野】本発明はペ−ジャ−等、通信関係
の電子装置等に用いられる弾性表面波素子に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device used in communication-related electronic devices such as pagers.
【０００２】0002
【従来の技術】従来の弾性表面波素子の電極構造は、圧
電性を有する基板上に電気伝導性を有する物質のみで、
櫛歯型電極を形成したものであった。また、保護膜を形
成する場合、電極形成後に基板および電極の上から全面
に渡り酸化シリコン膜などを形成した構成であった。[Prior Art] The electrode structure of a conventional surface acoustic wave device consists of only an electrically conductive material on a piezoelectric substrate.
A comb-shaped electrode was formed. Furthermore, when forming a protective film, a silicon oxide film or the like was formed over the entire surface of the substrate and electrodes after the electrodes were formed.
【０００３】0003
【発明が解決しようとする課題】しかし、前述の従来技
術では弾性表面波が伝播し振動しているうちに、電極が
腐食し、または酸化し周波数が変化するなど、特性が悪
くなるという課題を有する。また、酸化シリコン膜を電
極及び基板の全面に形成する構成では、基板上の形成物
により粘性ロスが生じるため、素子の基本特性（Ｑ値，
周波数，ＣＩ値等）が変化したり、また工程が増えるな
どの課題を有していた。さらに金属保護膜は電極間を短
絡させてしまうため、使用できないという課題を有して
いた。[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has a problem in that while the surface acoustic waves propagate and vibrate, the electrodes corrode or oxidize, causing the frequency to change and the characteristics to deteriorate. have In addition, in a configuration in which a silicon oxide film is formed on the electrode and the entire surface of the substrate, viscosity loss occurs due to the formation on the substrate, so the basic characteristics of the element (Q value,
However, there were problems such as changes in frequencies (frequency, CI values, etc.) and an increase in the number of steps. Furthermore, a metal protective film has the problem of being unusable because it short-circuits between electrodes.
【０００４】0004
【課題を解決するための手段】本発明の弾性表面波素子
は、圧電性を有する基板上に、電気伝導性を有する物質
により櫛歯型に形成された電極を持つ弾性表面波素子に
おいて、電極表面に保護膜を形成したことを特徴とする
。この保護膜は、クロム，チタンなど腐食に強い金属や
、酸化シリコンなどの酸化膜である。またこれらの保護
膜は、電極を形成するときに同時に形成される。[Means for Solving the Problems] The surface acoustic wave device of the present invention has electrodes formed in a comb-like shape using an electrically conductive substance on a piezoelectric substrate. It is characterized by a protective film formed on the surface. This protective film is made of a corrosion-resistant metal such as chromium or titanium, or an oxide film such as silicon oxide. Further, these protective films are formed simultaneously when forming the electrodes.
【０００５】[0005]
【実施例】以下、本発明を実施例を用いて説明する。EXAMPLES The present invention will be explained below using examples.
【０００６】図１は本発明による一実施例の弾性表面波
素子１の上面図である。図２は、図１の弾性表面波素子
１の任意の１本の電極構造を示す断面図である。図１記
載の弾性表面波素子１は、中央に電気信号と弾性表面波
との変換を行なう櫛歯型のインターデジタルトランスデ
ューサー（ＩＤＴ）２を有し、その両側に格子上の反射
器（ＲＥＦ）３を有する共振子である。このＩＤＴとＲ
ＥＦを電極という。ただし実際の電極本数はＲＥＦ３０
０本、ＩＤＴ２００対であり図１は本数を減らして描い
てある。図１の圧電性を有する基板４はＳＴカット水晶
からなっている。電極の幅は約５ミクロンであり、本弾
性表面波素子の共振周波数は１５０メガヘルツ帯域であ
る。FIG. 1 is a top view of a surface acoustic wave device 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the structure of any one electrode of the surface acoustic wave element 1 of FIG. 1. As shown in FIG. The surface acoustic wave element 1 shown in FIG. 1 has a comb-shaped interdigital transducer (IDT) 2 in the center that converts an electric signal and a surface acoustic wave, and a reflector on a grid (REF) on both sides. )3. This IDT and R
EF is called an electrode. However, the actual number of electrodes is REF30.
There are 0 pairs of IDTs and 200 pairs of IDTs, and FIG. 1 is drawn with a reduced number of pairs. The piezoelectric substrate 4 shown in FIG. 1 is made of ST-cut crystal. The width of the electrode is approximately 5 microns, and the resonant frequency of this surface acoustic wave element is in the 150 MHz band.
【０００７】本発明の弾性表面波素子１の電極（ＩＤＴ
とＲＥＦ）構造は２層から成っている。図２に示すごと
く、第１層５にはアルミニウムが６０００オングストロ
ーム，第２層６には保護膜であるクロムが１００オング
ストローム成膜してある。Electrode (IDT) of surface acoustic wave device 1 of the present invention
and REF) structure consists of two layers. As shown in FIG. 2, the first layer 5 is made of aluminum with a thickness of 6000 angstroms, and the second layer 6 is made of chromium, which is a protective film, with a thickness of 100 angstroms.
【０００８】本実施例では、この電極の形成方法として
リフトオフ法を用いている。以下に、図３の（ａ）から
（ｅ）を用いて本実施例におけるリフトオフプロセスを
説明する。図３（ａ）に示すように水晶基板上２に、光
反応性樹脂（レジスト）５を塗布し、図３（ｂ）に示す
ように、その上面に所望の電極図形を描いた光遮蔽板（
マスク）６を通し露光する。次に、現像液により現像し
、図３（ｃ）に示すようにレジストパターン８を得る。
レジストによって形成されたパターン上に図３（ｄ）に
示すようにアルミニウム層５を蒸着法、スパッタ法、ま
たはその他の方法により成膜する。さらにその上に同様
の方法で、クロム層６を形成する。この状態で基板をレ
ジスト剥離液に浸漬すると、レジストパターンは剥離液
に溶解するため、電極部以外のアルミニウム層及びクロ
ム層をレジストと同時に除去することができる。以上の
方法により、図３（ｅ）に示すようにアルミニウム電極
の表面にのみ同一工程で保護膜となるクロム膜を形成し
た弾性表面波素子を得ることができる。このとき、重量
バランスを考慮してアルミニウムとクロムの膜厚を適当
に定めれば、素子の基本特性は殆ど変化することがない
。また、基板上には保護膜が付かないので電極が短絡す
ることがなく、Ｑ値の変化も殆どない。In this embodiment, a lift-off method is used as a method for forming this electrode. The lift-off process in this example will be explained below using FIGS. 3(a) to 3(e). As shown in FIG. 3(a), a photoreactive resin (resist) 5 is coated on a crystal substrate 2, and as shown in FIG. 3(b), a light shielding plate has a desired electrode pattern drawn on its upper surface. (
Expose through mask) 6. Next, it is developed with a developer to obtain a resist pattern 8 as shown in FIG. 3(c). As shown in FIG. 3D, an aluminum layer 5 is formed on the pattern formed by the resist by vapor deposition, sputtering, or other methods. Furthermore, a chromium layer 6 is formed thereon by the same method. If the substrate is immersed in a resist stripping solution in this state, the resist pattern will be dissolved in the stripping solution, so that the aluminum layer and chromium layer other than the electrode portions can be removed at the same time as the resist. By the above method, it is possible to obtain a surface acoustic wave element in which a chromium film serving as a protective film is formed only on the surface of the aluminum electrode in the same step, as shown in FIG. 3(e). At this time, if the film thicknesses of aluminum and chromium are appropriately determined in consideration of weight balance, the basic characteristics of the element will hardly change. Furthermore, since no protective film is formed on the substrate, there is no short-circuiting of the electrodes, and there is almost no change in the Q value.
【０００９】本実施例のレジストには、光の照射された
部分が現像液に溶解するポジ型フォトレジストを用いて
おり、厚みは約１．５ミクロンである。また、本タイプ
と逆のネガ型フォトレジストも可能である。ただしこの
場合は光遮蔽板のパターンも反転する。The resist used in this embodiment is a positive type photoresist in which the light-irradiated portion dissolves in a developer, and has a thickness of approximately 1.5 microns. Also, a negative photoresist, which is the opposite of this type, is also possible. However, in this case, the pattern of the light shielding plate is also reversed.
【００１０】本実施例の電極第１層アルミニウム層５を
、蒸着法により成膜したときの成膜条件を以下に示す。
すなわち蒸着前到達圧力は、０．７マイクロトリチェリ
，蒸着タ−ゲットは、アルミニウム，基板加熱温度は、
摂氏１３０度，蒸着速度は、毎秒３０オングストローム
である。つぎに、電極第２層であるクロム層６を蒸着法
により成膜したときの成膜条件を以下に示す。すなわち
蒸着前到達圧力は、０．７マイクロトリチェリ，蒸着タ
−ゲットは、クロム，基板加熱温度は、摂氏１３０度，
蒸着速度は、毎秒１オングストロームである。蒸着方式
は、アルミニウム，クロムとも電子銃による加熱方式で
ある。The film-forming conditions for forming the electrode first aluminum layer 5 of this example by a vapor deposition method are shown below. That is, the ultimate pressure before evaporation was 0.7 microtorch, the evaporation target was aluminum, and the substrate heating temperature was:
The temperature was 130 degrees Celsius and the deposition rate was 30 angstroms per second. Next, the film forming conditions for forming the chromium layer 6, which is the second electrode layer, by a vapor deposition method are shown below. That is, the ultimate pressure before vapor deposition was 0.7 microtorch, the vapor deposition target was chromium, the substrate heating temperature was 130 degrees Celsius,
The deposition rate is 1 angstrom per second. The vapor deposition method is a heating method using an electron gun for both aluminum and chromium.
【００１１】図４は、従来の電極表面に保護膜を形成し
ない弾性表面波素子の、共振周波数の動作時における経
時変化を示したものである。時間の経過に伴い、中心周
波数が変化していくことがわかる。この変化は、電極と
なるアルミニウム層は柔らかい材質であるため、電極形
成後の加工工程において、傷を付けたりクラックを生じ
させることがあり、弾性表面波素子が伝播し振動すると
、経時変化に伴い電極の一部が割れたり脱落するために
起こる。または、経時変化に伴いケース中の残留ガスや
接着剤から発生するガスにより、アルミニウム層が腐食
されたためと考えられる。このため、アルミニウム電極
の応力が変化し周波数が変化してしまう。図５は、本発
明における電極表面に保護膜を形成した弾性表面波素子
の、共振周波数の動作時における経時変化を示したもの
である。時間が経過しても、中心周波数の変化が少ない
ことがわかる。これは、クロム層によって電極であるア
ルミニウム層が保護されているため、加工による割れ及
びクラック、または動作時における腐食を防ぐことがで
きるためである。FIG. 4 shows the change in resonance frequency over time during operation of a conventional surface acoustic wave device in which no protective film is formed on the electrode surface. It can be seen that the center frequency changes as time passes. This change occurs because the aluminum layer that serves as the electrode is a soft material, so it may be scratched or cracked during the processing process after forming the electrode, and as the surface acoustic wave element propagates and vibrates, it will change over time. This occurs because part of the electrode cracks or falls off. Alternatively, it is thought that the aluminum layer was corroded by residual gas in the case or gas generated from the adhesive over time. For this reason, the stress of the aluminum electrode changes and the frequency changes. FIG. 5 shows the change in resonance frequency over time during operation of a surface acoustic wave element in which a protective film is formed on the electrode surface according to the present invention. It can be seen that there is little change in the center frequency over time. This is because the aluminum layer, which is the electrode, is protected by the chromium layer, thereby preventing cracks and cracks caused by processing or corrosion during operation.
【００１２】本実施例では、電極材料としてアルミニウ
ムを用いたがアルミニウム合金でも可能である。In this embodiment, aluminum was used as the electrode material, but an aluminum alloy may also be used.
【００１３】本実施例では、電極の保護膜としてクロム
膜を用いたが、他の耐食性の強い材質、例えばチタン膜
，白金膜，金膜，タンタル膜，タングステン膜等でもよ
い。ただし膜厚は各々適当な厚みにする必要がある。
これらはいずれも蒸着法またはスパッタ法により形成さ
れる。さらに二酸化シリコン，窒化シリコン，炭化シリ
コン，五酸化タンタル，酸化ジルコニア等の誘電体膜等
も可能である。In this embodiment, a chromium film is used as the protective film for the electrode, but other highly corrosion-resistant materials such as titanium film, platinum film, gold film, tantalum film, tungsten film, etc. may also be used. However, each film needs to have an appropriate thickness. All of these are formed by a vapor deposition method or a sputtering method. Furthermore, dielectric films such as silicon dioxide, silicon nitride, silicon carbide, tantalum pentoxide, and zirconia oxide are also possible.
【００１４】また、本実施例では図１に示した弾性表面
波共振子の電極構造について説明したが、弾性表面波フ
ィルターへの応用も可能である。Further, in this embodiment, the electrode structure of the surface acoustic wave resonator shown in FIG. 1 has been described, but application to a surface acoustic wave filter is also possible.
【００１５】また、圧電体基板はＳＴカット水晶基板を
用いたが他のカットの水晶基板（ＬＳＴカット等）や、
他の材質の基板（タンタル酸リチウム，ニオブ酸リチウ
ム，ほう酸リチウム等）、あるいは薄膜圧電材料（酸化
亜鉛，窒化アルミニウム等）でもよい。Although an ST-cut crystal substrate was used as the piezoelectric substrate, other cut crystal substrates (such as LST cut),
A substrate made of other materials (lithium tantalate, lithium niobate, lithium borate, etc.) or a thin film piezoelectric material (zinc oxide, aluminum nitride, etc.) may be used.
【００１６】[0016]
【発明の効果】以上述べたように本発明によれば、弾性
表面波素子における櫛歯型電極の構造を、電極表面に保
護膜を形成することにより、電極材料の割れやクラック
の発生を防止することができ、経時変化に伴う腐食も防
ぐことができる。そのため、弾性表面波素子の動作経時
変化による、共振周波数の変化を少なくでき、信頼性の
高い弾性表面波素子を提供できるという効果を有する。As described above, according to the present invention, the structure of the comb-shaped electrode in a surface acoustic wave element is prevented from cracking or cracking in the electrode material by forming a protective film on the electrode surface. It is also possible to prevent corrosion caused by changes over time. Therefore, it is possible to reduce changes in the resonant frequency due to changes in the operation of the surface acoustic wave element over time, and it is possible to provide a highly reliable surface acoustic wave element.
【００１７】また、リフトオフ法により、電極と保護膜
を同一工程で形成できるため工程が簡略化できるという
効果を有する。さらに保護膜を電極表面にのみ形成する
ため、金属の保護膜を用いることができる。また基板上
の電極間に保護膜がないため素子の基本特性を劣化させ
ることもない。Furthermore, the lift-off method has the effect of simplifying the process because the electrode and the protective film can be formed in the same process. Furthermore, since the protective film is formed only on the electrode surface, a metal protective film can be used. Furthermore, since there is no protective film between the electrodes on the substrate, the basic characteristics of the device will not deteriorate.
【図１】本発明の一実施例による弾性表面波素子の正面
図。FIG. 1 is a front view of a surface acoustic wave device according to an embodiment of the present invention.
【図２】本発明の一実施例による弾性表面波素子の任意
の一本の電極構造を示す断面図。FIG. 2 is a cross-sectional view showing the structure of one arbitrary electrode of a surface acoustic wave device according to an embodiment of the present invention.
【図３】本発明の一実施例による弾性表面波素子の製造
工程を示す説明図。FIG. 3 is an explanatory diagram showing a manufacturing process of a surface acoustic wave device according to an embodiment of the present invention.
【図４】従来技術による弾性表面波素子の動作経時変化
を示す特性図。FIG. 4 is a characteristic diagram showing changes over time in the operation of a surface acoustic wave element according to the prior art.
【図５】本発明による弾性表面波素子の動作経時変化を
示す特性図。FIG. 5 is a characteristic diagram showing changes over time in the operation of the surface acoustic wave element according to the present invention.
１ 弾性表面波素子 ２ 櫛歯型電極 ３ 格子状反射器電極 ４ 圧電体基板 ５ 第１層アルミニウム層 ６ 第２層クロム層 ７ 光反応性樹脂（レジスト） ８ 光遮蔽板（マスク） ９ レジストパターン 1 Surface acoustic wave device 2 Comb-shaped electrode 3. Grid reflector electrode 4 Piezoelectric substrate 5 First layer aluminum layer 6 Second layer chromium layer 7 Photoreactive resin (resist) 8. Light shielding plate (mask) 9 Resist pattern
Claims (4)
を有する物質により櫛歯型に形成された電極を持つ弾性
表面波素子において、電極表面に保護膜を形成したこと
を特徴とする弾性表面波素子。1. A surface acoustic wave element having a comb-shaped electrode made of an electrically conductive substance on a piezoelectric substrate, characterized in that a protective film is formed on the surface of the electrode. surface wave element.
タン，金，白金，タングステン，またはタンタルである
ことを特徴とする、請求項１記載の弾性表面波素子。2. The surface acoustic wave device according to claim 1, wherein the protective film on the electrode surface is made of chromium, titanium, gold, platinum, tungsten, or tantalum.
コン，窒化シリコン，炭化シリコン，五酸化タンタル，
酸化ジルコニア等の誘電体であることを特徴とする請求
項１記載の弾性表面波素子。3. The protective film on the electrode surface is made of silicon dioxide, silicon nitride, silicon carbide, tantalum pentoxide,
2. The surface acoustic wave device according to claim 1, wherein the surface acoustic wave device is made of a dielectric material such as oxidized zirconia.
極と表面保護膜を、リフトオフ法で形成したことを特徴
とする請求項１記載の弾性表面波素子。4. The surface acoustic wave device according to claim 1, wherein the electrode and surface protective film made of the electrically conductive substance are formed by a lift-off method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6030191A JPH04294625A (en) | 1991-03-25 | 1991-03-25 | Surface acoustic wave element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6030191A JPH04294625A (en) | 1991-03-25 | 1991-03-25 | Surface acoustic wave element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04294625A true JPH04294625A (en) | 1992-10-19 |
Family
ID=13138216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6030191A Pending JPH04294625A (en) | 1991-03-25 | 1991-03-25 | Surface acoustic wave element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04294625A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001041304A1 (en) * | 1999-11-30 | 2001-06-07 | Tdk Corporation | Surface acoustic wave device and its production_method |
| US6861786B2 (en) * | 2001-06-22 | 2005-03-01 | Oki Electric Industry Co., Ltd. | Saw device |
| WO2009016906A1 (en) * | 2007-07-30 | 2009-02-05 | Murata Manufacturing Co., Ltd. | Elastic wave device and method for manufacturing the same |
| WO2017002513A1 (en) * | 2015-07-02 | 2017-01-05 | 株式会社村田製作所 | Acoustic wave device |
| JP2017220924A (en) * | 2016-06-07 | 2017-12-14 | 株式会社村田製作所 | Method for manufacturing acoustic wave device |
-
1991
- 1991-03-25 JP JP6030191A patent/JPH04294625A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001041304A1 (en) * | 1999-11-30 | 2001-06-07 | Tdk Corporation | Surface acoustic wave device and its production_method |
| US6580198B2 (en) | 1999-11-30 | 2003-06-17 | Tdk Corporation | Surface acoustic wave device having a thin metal oxide film fully covering at least the electrodes and method of fabricating same |
| US6861786B2 (en) * | 2001-06-22 | 2005-03-01 | Oki Electric Industry Co., Ltd. | Saw device |
| US7034435B2 (en) | 2001-06-22 | 2006-04-25 | Oki Electric Industry Co., Ltd. | Saw device |
| US7868523B2 (en) | 2007-07-30 | 2011-01-11 | Murata Manufacturing Co., Ltd. | Elastic wave device and method of producing the same |
| CN101765971A (en) * | 2007-07-30 | 2010-06-30 | 株式会社村田制作所 | Elastic wave device and method for manufacturing same |
| WO2009016906A1 (en) * | 2007-07-30 | 2009-02-05 | Murata Manufacturing Co., Ltd. | Elastic wave device and method for manufacturing the same |
| WO2017002513A1 (en) * | 2015-07-02 | 2017-01-05 | 株式会社村田製作所 | Acoustic wave device |
| KR20170137900A (en) * | 2015-07-02 | 2017-12-13 | 가부시키가이샤 무라타 세이사쿠쇼 | Seismic wave device |
| CN107615656A (en) * | 2015-07-02 | 2018-01-19 | 株式会社村田制作所 | Acoustic wave device |
| JPWO2017002513A1 (en) * | 2015-07-02 | 2018-02-15 | 株式会社村田製作所 | Elastic wave device |
| US10958238B2 (en) | 2015-07-02 | 2021-03-23 | Murata Manufacturing Co., Ltd. | Elastic wave device |
| JP2017220924A (en) * | 2016-06-07 | 2017-12-14 | 株式会社村田製作所 | Method for manufacturing acoustic wave device |
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