JPS6271317A - Manufacture of surface acoustic wave device - Google Patents
Manufacture of surface acoustic wave deviceInfo
- Publication number
- JPS6271317A JPS6271317A JP21167485A JP21167485A JPS6271317A JP S6271317 A JPS6271317 A JP S6271317A JP 21167485 A JP21167485 A JP 21167485A JP 21167485 A JP21167485 A JP 21167485A JP S6271317 A JPS6271317 A JP S6271317A
- Authority
- JP
- Japan
- Prior art keywords
- etching
- thin film
- substrate
- electrode
- etched
- 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
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
主1上皮机且立■
本発明は、弾性表面波装置(以下SAW装置と称す、)
の製造方法に関し、詳しくはその電極形成方法に関する
ものである。[Detailed Description of the Invention] The present invention is based on a surface acoustic wave device (hereinafter referred to as a SAW device).
The present invention relates to a manufacturing method, and more particularly to a method for forming an electrode.
従来立狡屯
近年、圧電効果によって弾性表面波を励起させ、共振子
やフィルタとして利用するSAW装置が知られてきてい
る0例えば、共振子として用いられるSAW素子を第5
図及び第6図に基づき説明すると、(1)は単結晶の水
晶、薄膜等の圧電性基板(以下、単に基板と称す、)、
(2)は一定間隔(λ)毎に区切られた櫛形の電極を一
対、櫛歯をかみ合わせてエツチング等の印刷技術により
形成した櫛形電極、(3)は櫛形電極(2)により励起
された表面波の反射器で、櫛形電極(2)の両側に表面
波の振動方向と直交するようなAn等の縦長の突起を所
定間隔で配設してなる回折格子である。In recent years, SAW devices that excite surface acoustic waves using piezoelectric effects and use them as resonators or filters have become known. For example, a SAW device used as a resonator can be
To explain based on the figures and FIG. 6, (1) is a piezoelectric substrate (hereinafter simply referred to as a substrate) such as a single crystal quartz or a thin film;
(2) is a comb-shaped electrode formed by a printing technique such as etching by interlocking a pair of comb-shaped electrodes separated at regular intervals (λ), and (3) is the surface excited by the comb-shaped electrode (2). It is a wave reflector, and is a diffraction grating in which vertically long protrusions made of An or the like are arranged at predetermined intervals on both sides of a comb-shaped electrode (2) so as to be orthogonal to the vibration direction of the surface wave.
上記構成において櫛形電極(2)にパルス電圧を印加す
ると、圧電効果により隣り合う電極間の基板表面に互い
に逆位相の歪みが生じ、波長(λ)の表面波が励起され
る。この表面波は反射器(3)の各突起に到達する毎に
反射波と透過波に分かれる。そこで、反射器(3)の各
突起からの反射波の位相が揃うように各突起間の間隔を
設けておけば、第6図に示すように、各反射器(3)(
3)間に波長(λ)の定在波が励起され共振子となる。In the above configuration, when a pulse voltage is applied to the comb-shaped electrode (2), a piezoelectric effect causes a distortion in opposite phases to occur on the substrate surface between adjacent electrodes, and a surface wave with a wavelength (λ) is excited. Each time this surface wave reaches each protrusion of the reflector (3), it is divided into a reflected wave and a transmitted wave. Therefore, if the intervals between the protrusions are set so that the phases of the reflected waves from each protrusion of the reflector (3) are aligned, each reflector (3) (
3) A standing wave of wavelength (λ) is excited between them and becomes a resonator.
そして、上記表面波の伝播速度を(V)、波長を(λ)
、共振周波数を(f)とすると、vxfλが成立ち、共
振周波数(f)は、f−V/λで与えられる。ここで、
波長(λ)は櫛形電極(2)の電極間ピッチで決り、伝
播速度(v)は基板(1)の材質等で決まるが、更に基
板(1)上に形成された櫛形電極(2)による質量効果
の影響を受ける。上記質量効果は櫛形電極(2)の質量
、即ち膜厚によって伝播速度(V)が変わるもので、例
えば電極間ピッチ(λ)を変えずに櫛形電極(2)の膜
厚を厚くしていくと、伝播速度(V>は減少していき共
振周波数(f)は低下する。そこで、エツチング等で櫛
形電極(2)を形成する際、必要な共振周波数(f)を
得るため、櫛形電極(2)の電極間ピッチと共に膜厚を
制御して所定の厚さに設定しなければならない。Then, the propagation speed of the above surface wave is (V) and the wavelength is (λ)
, when the resonant frequency is (f), vxfλ holds true, and the resonant frequency (f) is given by f-V/λ. here,
The wavelength (λ) is determined by the interelectrode pitch of the comb-shaped electrode (2), and the propagation velocity (v) is determined by the material of the substrate (1), etc., but it is also determined by the comb-shaped electrode (2) formed on the substrate (1). Affected by mass effect. The mass effect mentioned above is that the propagation velocity (V) changes depending on the mass of the comb-shaped electrode (2), that is, the film thickness. For example, if the film thickness of the comb-shaped electrode (2) is increased without changing the inter-electrode pitch (λ). , the propagation velocity (V>) decreases and the resonant frequency (f) decreases. Therefore, when forming the comb-shaped electrode (2) by etching etc., in order to obtain the necessary resonant frequency (f), the comb-shaped electrode ( 2) The film thickness must be set to a predetermined thickness by controlling the pitch between the electrodes as well as the film thickness.
上記櫛形電極(2)は、通常、印刷技術にて形成され、
第7図に示すように、基板表面にAi’等の金属薄膜(
2a)を蒸着し、次に第8図に示すように、藩着面に電
極パターンに等しいレジスト(4)を塗布した後、エツ
チングを施し形成される。The comb-shaped electrode (2) is usually formed by printing technology,
As shown in Figure 7, a metal thin film such as Ai' (
2a) is vapor-deposited, and then, as shown in FIG. 8, a resist (4) equivalent to the electrode pattern is applied to the surface to which the electrode is deposited, followed by etching.
J”L−”と]、題遣方
ところで、櫛形電極(2)の電極幅は1〜3μ(m)の
ものであるため、電極を形成するに際してはリン酸等中
に浸して化学的に金属薄膜(2a)を溶かす等方性のウ
ェットエッチは不適当で、アルゴン等のイオンプラズマ
で金属薄膜(2a)を飛ばす異方性のドライエッチが用
いられる。ところが、ドライエッチにて金属薄膜(2a
)をエツチングする際、電極断面を明確に現そうとする
ため、第9図に示すように、金属薄Ill! (2a)
に留まらず、下地の基板(1)の表面の一部までエツチ
ングされる。その結果、櫛形電極(2)の質量効果がエ
ツチング後の基板(1)の表面凸部まで及ぶため、金B
薄n (2a)の膜厚だけでなく基板(1)のエツチン
グ深さまで制御しなければならず、電極膜厚の設定が困
難となる。又、金属薄1) (2a)は蒸着にて形成さ
れており、表面に凹凸があるため、ドライエッチにより
均一のエツチングレートにてエツチングすると、基板(
1)の表面にも金属薄膜(2a)表面の凹凸がそのまま
形成される。By the way, the electrode width of the comb-shaped electrode (2) is 1 to 3μ (m), so when forming the electrode, it must be chemically immersed in phosphoric acid, etc. Isotropic wet etching that melts the metal thin film (2a) is inappropriate, and anisotropic dry etching that evaporates the metal thin film (2a) with ion plasma such as argon is used. However, the metal thin film (2a
), in order to clearly show the cross section of the electrode, the thin metal Ill! is etched as shown in Figure 9. (2a)
Not only this, but also a part of the surface of the underlying substrate (1) is etched. As a result, the mass effect of the comb-shaped electrode (2) extends to the surface protrusions of the substrate (1) after etching, so that the gold B
It is necessary to control not only the thickness of the thin n (2a) film but also the etching depth of the substrate (1), making it difficult to set the electrode film thickness. In addition, since the metal thin film 1) (2a) is formed by vapor deposition and has an uneven surface, if it is etched at a uniform etching rate by dry etching, the substrate (
The unevenness of the surface of the metal thin film (2a) is also formed on the surface of 1).
° るための
本発明は、圧電性基板上に金属薄膜を蒸着した後、エツ
チングにて薄膜の櫛形電極を形成し弾性表面波装置を製
造するにあたり、上記基板に蒸着した金属薄膜を、基板
が露出する直前までドライエッチにてエツチングした後
、ドライエッチによって残った金属薄膜をウェットエッ
チに゛てエツチングし上記電極を形成することを特徴と
する。According to the present invention, when manufacturing a surface acoustic wave device by depositing a metal thin film on a piezoelectric substrate and then forming a thin film comb-shaped electrode by etching, the metal thin film deposited on the piezoelectric substrate is The electrode is formed by etching the metal thin film by dry etching until just before exposure, and then etching the metal thin film remaining by dry etching by wet etching.
作l−
圧電性基板に金属薄膜を蒸着し、下地の基板が露出する
手前までドライエッチにてエツチングした後、残りの金
属薄膜をウェットエッチにてエツチングし薄膜の櫛形電
極を形成すると、金属薄膜のみエツチングされて電極が
形成され基板までエツチングが及ばない。Production 1 - After depositing a metal thin film on a piezoelectric substrate and etching it by dry etching until just before the underlying substrate is exposed, the remaining metal thin film is etched by wet etching to form a thin comb-shaped electrode. The electrodes are formed by etching only the etching layer, and the etching does not reach the substrate.
に■
本発明に係るSAW装置の製造方法を通用した一実施例
を第1図乃至第4図を参照して通用順に以下説明する。(2) An embodiment in which the method of manufacturing a SAW device according to the present invention is applied will be described below in the order of application with reference to FIGS. 1 to 4.
本発明は、SAW装置における薄膜の櫛形電極(2)の
形成に通用される製造方法であって、まず、第1図に示
すように、従来と同じく基板(1)にAJ等の金属薄膜
(2a)を蒸着した後、電極形成部分にレジスト(4)
を塗布し、アルゴンのイオンプラズマによるドライエッ
チにて金属Km (2a)をエツチング(第1段階のエ
ツチング)する。このドライエッチによる第1段階のエ
ツチングは異方性のエツチングであって縦方向にエツチ
ングされるが、第2図に示すように、下地の基板(1)
が露出する手前で中止する。次に、第1段階のエツチン
グ後に基板(1)上に残った金属薄膜(2a)をリン酸
と硝酸の混酸中に浸し、ウェットエッチにてエツチング
(第2段階のエツチング)し除去する。そうすると、、
水晶等の基板(1)はウェットエッチにて除去されない
ため、第3図に示すように、レジスト(4)が塗布され
た電Ji形成部分において周囲の基板(1)をエツチン
グすることなく所定の膜厚で電極断面を明確に現すこと
ができる。ここで、ウェットエッチは等方性のエツチン
グであるため、エツチング時間を長くしてオーバーエツ
チングすると、第4図に示すように、電極(2)の側面
までエツチングされてくる。そこで、これを利用し、周
波数をチェックしながら電極(2)の側面までオーバー
エツチングすることにより、周波数の−整を行うことが
できる。The present invention is a manufacturing method commonly used for forming a thin film comb-shaped electrode (2) in a SAW device.First, as shown in FIG. After depositing 2a), resist (4) is applied to the electrode formation area.
The metal Km (2a) is etched by dry etching using argon ion plasma (first stage etching). The first stage of dry etching is anisotropic etching and is etched in the vertical direction, but as shown in Figure 2, the underlying substrate (1)
Stop before it is exposed. Next, the metal thin film (2a) remaining on the substrate (1) after the first stage etching is immersed in a mixed acid of phosphoric acid and nitric acid, and is etched by wet etching (second stage etching) to be removed. Then,...
Since the substrate (1) such as crystal is not removed by wet etching, as shown in Fig. 3, the resist (4) is applied to the predetermined area where the resist (4) is applied without etching the surrounding substrate (1). The cross section of the electrode can be clearly expressed by the film thickness. Here, since wet etching is isotropic etching, if the etching time is increased to cause overetching, the side surfaces of the electrode (2) will be etched as shown in FIG. 4. Therefore, by utilizing this and over-etching to the side surface of the electrode (2) while checking the frequency, the frequency can be adjusted.
ユニ坐量宋
本発明によれば、S A W装置の薄膜の櫛形電也を圧
電性基板上にエツチングにて形成しSAv、r装置を製
造するにあたり、全圧薄膜をドライエッチにて基板が露
出する手前までエツチングした後、ドライエッチで残っ
た金属薄膜をウェットエッチにてエツチングし断面を明
確にして電極を形成するようにしたから、金属薄膜の膜
厚だけで電橋膜厚を制御することができ、SAW装五の
周波数の制御と調整を高い精度で容易に行うことができ
る。According to the present invention, when manufacturing the SAv,r device by forming the thin film comb-shaped wire of the SAW device on the piezoelectric substrate by etching, the substrate is etched by dry etching the full-thickness thin film. After etching to the point where it is exposed, the thin metal film remaining from dry etching is etched using wet etching to make the cross section clear and form electrodes, so the thickness of the bridge can be controlled solely by the thickness of the thin metal film. Therefore, it is possible to easily control and adjust the frequency of the SAW device with high precision.
第1図と第2図と第3図と第4図は本発明に係るSAW
装置の製造方法を通用して製造される薄膜の櫛形電極の
各工程における部分断面図、第5図はSAW装置の一具
体例であるSAW共振子の斜視図、第6図は第5図のA
−A線断面図、第7図は金属薄膜を蒸着した圧電性基板
の斜視図、第8図は第7図の金属s膜の74掻パターン
にレジストを塗布した圧電性基板の斜視図、第9図は従
来の問題点を説明するためのSAW装置の薄膜の櫛形電
捲の部分拡大断面図である。
(1)・−圧電性基板、(2m−薄膜櫛形電極、(2a
)−金属薄膜。
特許出願人 関西日本電気株式会社 B−一゛=w
゛1
代理人 江 原 省 吾 ゛・−’、、’−1図面の
浄書(内容に変更なし)
第3Lん 第4<j
第7図
手続補正書
昭和61年 2月25日
特許庁長官 宇 賀 道 部 殿
1、事件の表示
昭和60年 特許層 第21)674号2、発明の名称
弾性表面波装置の製造方法3、補正をする者
事件との関係 特許出願人
名称 関西日本電気株式会社
4、代理人
住 所 大阪府大阪市西区江戸堀1丁目15番26号
大阪商エビルア階
氏 名 (645B)弁理士 江 原 省 吾5、補
正命令の日付
昭和61年1月8日
(発送日 昭和61年1月28日)
6、補正の対象 図 面
7、?ili正の内容 図面企図を別紙の通り補正する
。1, 2, 3 and 4 are SAWs according to the present invention.
FIG. 5 is a perspective view of a SAW resonator, which is a specific example of a SAW device, and FIG. A
7 is a perspective view of a piezoelectric substrate on which a metal thin film has been deposited, and FIG. FIG. 9 is a partially enlarged sectional view of a thin film comb-shaped electric winding of a SAW device for explaining the conventional problems. (1)・-Piezoelectric substrate, (2m-thin film comb-shaped electrode, (2a
) - metal thin film. Patent applicant: Kansai NEC Co., Ltd. B-1゛=w
゛1 Agent: Sho Ebara ゛・-',,'-1 Engraving of the drawings (no changes to the contents) No. 3L No. 4<j Figure 7 Procedural Amendment February 25, 1986 Commissioner of the Patent Office U Ka Michibe 1, Indication of the case 1985 Patent layer No. 21) No. 674 2, Title of the invention Method of manufacturing a surface acoustic wave device 3, Relationship with the person making the amendment Case Name of patent applicant Kansai NEC Co., Ltd. 4. Address of agent: 1-15-26 Edobori, Nishi-ku, Osaka-shi, Osaka Prefecture, Osaka Sho Ebiru, Tokyo Name (645B) Patent attorney: Shogo Ehara 5. Date of amendment order: January 8, 1985 (Date of dispatch: Showa) (January 28, 1961) 6. Subject of amendment Drawing 7.? ili Correct contents Amend the drawing plan as shown in the attached sheet.
Claims (1)
グにて薄膜櫛形電極を形成し、弾性表面波装置を製造す
るにあたり、上記基板に蒸着した金属薄膜を、基板が露
出する直前までドライエッチにてエッチングし、次いで
残された金属薄膜をウェットエッチにてエッチングし、
上記電極を形成することを特徴とする弾性表面波装置の
製造方法。(1) After depositing a metal thin film on a piezoelectric substrate, a thin film comb-shaped electrode is formed by etching, and when manufacturing a surface acoustic wave device, the metal thin film deposited on the substrate is dried until just before the substrate is exposed. Etching with etch, then etching the remaining metal thin film with wet etch,
A method of manufacturing a surface acoustic wave device, comprising forming the above electrode.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21167485A JPS6271317A (en) | 1985-09-24 | 1985-09-24 | Manufacture of surface acoustic wave device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21167485A JPS6271317A (en) | 1985-09-24 | 1985-09-24 | Manufacture of surface acoustic wave device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6271317A true JPS6271317A (en) | 1987-04-02 |
Family
ID=16609713
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP21167485A Pending JPS6271317A (en) | 1985-09-24 | 1985-09-24 | Manufacture of surface acoustic wave device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6271317A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7194793B2 (en) | 2000-09-06 | 2007-03-27 | Murata Manufacturing Co., Ltd. | Method for producing an edge reflection type surface acoustic wave device |
US10418967B2 (en) | 2014-07-25 | 2019-09-17 | Seiko Epson Corporation | Resonator element, manufacturing method for resonator element, resonator, electronic device, and moving object |
-
1985
- 1985-09-24 JP JP21167485A patent/JPS6271317A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7194793B2 (en) | 2000-09-06 | 2007-03-27 | Murata Manufacturing Co., Ltd. | Method for producing an edge reflection type surface acoustic wave device |
US10418967B2 (en) | 2014-07-25 | 2019-09-17 | Seiko Epson Corporation | Resonator element, manufacturing method for resonator element, resonator, electronic device, and moving object |
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