JPH0236608A - Frequency adjusting method for surface acoustic wave element - Google Patents
Frequency adjusting method for surface acoustic wave elementInfo
- Publication number
- JPH0236608A JPH0236608A JP18770488A JP18770488A JPH0236608A JP H0236608 A JPH0236608 A JP H0236608A JP 18770488 A JP18770488 A JP 18770488A JP 18770488 A JP18770488 A JP 18770488A JP H0236608 A JPH0236608 A JP H0236608A
- Authority
- JP
- Japan
- Prior art keywords
- film
- acoustic wave
- surface acoustic
- frequency
- silicon dioxide
- 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.)
- Granted
Links
- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims abstract description 21
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 68
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 24
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 24
- 229910052814 silicon oxide Inorganic materials 0.000 claims abstract description 21
- 229910052581 Si3N4 Inorganic materials 0.000 claims abstract description 9
- 238000005268 plasma chemical vapour deposition Methods 0.000 claims abstract description 6
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims abstract description 5
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000000758 substrate Substances 0.000 claims description 11
- 239000002344 surface layer Substances 0.000 claims description 7
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 claims description 6
- 239000013078 crystal Substances 0.000 claims description 5
- 238000001020 plasma etching Methods 0.000 claims description 4
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 claims description 4
- 238000005566 electron beam evaporation Methods 0.000 claims description 3
- 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 3
- 239000011248 coating agent Substances 0.000 abstract description 2
- 238000000576 coating method Methods 0.000 abstract description 2
- 229910052681 coesite Inorganic materials 0.000 abstract description 2
- 229910052906 cristobalite Inorganic materials 0.000 abstract description 2
- 238000010894 electron beam technology Methods 0.000 abstract description 2
- 229910052682 stishovite Inorganic materials 0.000 abstract description 2
- 229910052905 tridymite Inorganic materials 0.000 abstract description 2
- 239000000126 substance Substances 0.000 abstract 1
- 238000007740 vapor deposition Methods 0.000 abstract 1
- 230000010355 oscillation Effects 0.000 description 22
- 238000005530 etching Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 230000001902 propagating effect Effects 0.000 description 3
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910012463 LiTaO3 Inorganic materials 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000029305 taxis Effects 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔概要〕
弾性表面波素子の発振周波数を調整するための方法に関
し、
特に高周波素子の周波数調整を容易かつ高精度化するこ
とを目的とし、
リチウムタンタレート単結晶のＸ軸廻りにＺ軸方向へ３
６度回転させたＹ仮から切り出した基板上に電極を形成
し、その上にプラズマＣＶＤにより屈折率が１．４６±
０．０１の二酸化シリコン膜を積層した弾性表面波素子
において、
該二酸化シリコン膜の上に、電子ビーム蒸着法によって
酸化シリコン膜または五酸化タンタル膜あるいは窒化シ
リコン膜を積層することを特徴とする、
ならびに、該弾性表面波素子において、四フフ化炭素を
用いたプラズマエツチングにより、前記二酸化シリコン
膜の表層部を除去することを特徴とし構成する。[Detailed Description of the Invention] [Summary] Regarding a method for adjusting the oscillation frequency of a surface acoustic wave device, particularly for the purpose of facilitating and increasing the precision of frequency adjustment of a high-frequency device, around the axis in the Z-axis direction 3
An electrode is formed on a substrate cut out from a Y temporary rotated by 6 degrees, and a refractive index of 1.46± is formed on it by plasma CVD.
A surface acoustic wave device in which a 0.01 silicon dioxide film is laminated, characterized in that a silicon oxide film, a tantalum pentoxide film, or a silicon nitride film is laminated on the silicon dioxide film by an electron beam evaporation method. Further, in the surface acoustic wave element, the surface layer portion of the silicon dioxide film is removed by plasma etching using carbon tetrafluoride.
本発明は、ＶＨＦ、ＵＨＦ周波数帯域において信号処理
等に使用される弾性表面波素子、特にその周波数調整方
法に関する。The present invention relates to a surface acoustic wave element used for signal processing, etc. in the VHF and UHF frequency bands, and particularly to a frequency adjustment method thereof.
近年の情報処理機器２通信機器の高速化に伴って、これ
らの装置中で使用される周波数は、高周波へ移行してい
る。また、高周波における基準信号の発生、フィルタリ
ング等が必要となり、これらの用途に弾性表面波素子が
使用されているが、周波数の高精度化が要求されている
前記機器において、該素子の高精度化および安定化が望
まれている。As information processing equipment 2 and communication equipment have become faster in recent years, the frequencies used in these devices have shifted to higher frequencies. In addition, generation of reference signals at high frequencies, filtering, etc. are required, and surface acoustic wave elements are used for these purposes. and stabilization is desired.
弾性表面波素子を用いたフィルタの挿入損失や比帯域幅
、ＶＣＯとしての周波数可変幅の点で、大きな結合係数
をもつにも係わらず比較的温度係数の優れたリチウムタ
ンタレート（ＬｉＴａＯ＋）の圧電体、特にリチウムタ
ンタレート単結晶のＸ軸廻りにＺ軸方向へ３６度回転さ
せたＹ板（３６’ Ｙ −ＸＬｉＴａｇ、板）から切り
出した圧電体を利用した素子は、極めて有用であり、現
在、この３６ ” Ｙ −ＸＬｉＴａ０゜板上に二酸化
シリコン（Ｓｉｎｔ）を積層し、温度特性を改善する試
みがなされている。かかる基板上に電極を形成した素子
は、電極の膜厚および電極幅ならびにＳｉＯ□の膜厚変
化等によって、周波数にばらつきを生じるため、その周
波数調整が必要となる。Lithium tantalate (LiTaO+) piezoelectric material has a relatively excellent temperature coefficient despite having a large coupling coefficient in terms of insertion loss and specific bandwidth of filters using surface acoustic wave elements, and frequency variable width as a VCO. Elements that utilize a piezoelectric material cut out from a Y plate (36' Y-XLiTag, plate) rotated 36 degrees around the X-axis of a lithium tantalate single crystal in the Z-axis direction are extremely useful and currently available. , an attempt has been made to stack silicon dioxide (Sint) on this 36" Y-XLiTa 0° plate to improve its temperature characteristics. Elements in which electrodes are formed on such a substrate have the following characteristics: Since variations in frequency occur due to changes in the film thickness of SiO□, etc., it is necessary to adjust the frequency.
第７図は弾性表面波素子の概略構成を示す平面図（イ）
とその断面図（ロ）、第８図（イ）、（ＩＩ）は３６゜
Ｙ −ＸＬｉＴａＯｘ板の説明図である。Figure 7 is a plan view (a) showing the schematic configuration of the surface acoustic wave element.
The cross-sectional view (B), FIGS. 8(A) and (II) are explanatory diagrams of the 36°Y-XLiTaOx plate.
第７図において、第８図に示すようにリチウムタンタレ
ート単結晶のＸ軸廻りにＺ軸方向へ３６度回転させたＹ
板（ウェーハ）ｌから圧電体３を切り出した弾性表面波
素子２は、圧電体３の上面の中央に駆動電極４を形成し
、駆動電極４の左方および右方位置に、反射電極５を形
成してなる。In Fig. 7, as shown in Fig. 8, the Y
The surface acoustic wave element 2 has a piezoelectric material 3 cut out from a plate (wafer) 1, and has a driving electrode 4 formed in the center of the upper surface of the piezoelectric material 3, and reflective electrodes 5 on the left and right sides of the driving electrode 4. It forms.
従来、かかる素子２の周波数調整方法は、電極４．５を
エツチングして薄くするまたは電極４゜５の一部をトリ
ミングする方法あるいは、圧電体３の電極間をエツチン
グする方法であった。Conventionally, the frequency adjustment method of such an element 2 has been a method of etching the electrodes 4.5 to make them thinner, a method of trimming a part of the electrodes 4.5, or a method of etching the space between the electrodes of the piezoelectric body 3.
また、弾性表面波素子２の温度特性を改善するため、第
柔図−（ＩＩ）に−点鎖線で示すようにＳｉＯ□膜６を
積層した弾性表面波素子では、紫外線照射による周波数
調整方法も報告されている。In addition, in order to improve the temperature characteristics of the surface acoustic wave element 2, a frequency adjustment method using ultraviolet irradiation is also available for the surface acoustic wave element in which the SiO□ film 6 is laminated, as shown by the dotted chain line in FIG. It has been reported.
Ｓｉｎ、膜６には屈折率が１．４６±０．０１のものを
使用しており、１．４６±０．０１から外れた屈折率の
Ｓｉｎｇ膜６を使用すると、温度特性の改善が損なわれ
るのみならず、他の電気特性をも低減させることになる
。The Sing film 6 has a refractive index of 1.46±0.01, and if the Sing film 6 has a refractive index outside of 1.46±0.01, the improvement in temperature characteristics will be impaired. Not only will this lead to a decrease in other electrical characteristics, but it will also reduce other electrical characteristics.
以上説明したように、電極または電極間の圧電体をエツ
チングする従来の周波数調整方法は、特に電極パターン
が微細化されると困難となり、高性能の所望周波数に対
して効率的かつ高精度に調整できないという問題点があ
った。As explained above, the conventional frequency adjustment method of etching the electrodes or the piezoelectric material between the electrodes becomes difficult, especially as the electrode pattern becomes finer, and it is difficult to efficiently and precisely adjust the desired frequency for high performance. The problem was that it couldn't be done.
本発明の実施例を示す第１図または第３図によれば、
リチウムタンタレート単結晶のＸ軸廻りにＺ軸方向へ３
６度回転させたＹ板から切り出した基板３上に駆動電極
４と反射電極５とを形成し、その上にプラズマＣＶＤに
より屈折率が１．４６±０．０１の二酸化シリコン膜６
を積層した弾性表面波素子１１において、
二酸化シリコン膜６の上に、電子ビーム蒸着法によって
酸化シリコン膜１２を積層することを特徴とした弾性表
面波素子１１の周波数調整方法、ならびに、リチウムタ
ンタレート単結晶のＸ軸廻りにＺ軸方向へ３６度回転さ
せたＹ板から切り出した基板３上に駆動電極４と反射電
極５とを形成し、その上にプラズマＣＶＤにより屈折率
が１．４６±０．０１の二酸化シリコン膜６を積層した
弾性表面波素子２１において、
四フッ化炭素を用いたプラズマエツチングにより、前記
二酸化シリコン膜６の表層部１６を除去することを特徴
とした弾性表面波素子の周波数調整方法である。According to FIG. 1 or FIG. 3 showing an embodiment of the present invention, three steps are taken in the Z-axis direction around the X-axis of the lithium tantalate single crystal.
A driving electrode 4 and a reflecting electrode 5 are formed on a substrate 3 cut out from a Y plate rotated by 6 degrees, and a silicon dioxide film 6 having a refractive index of 1.46±0.01 is formed thereon by plasma CVD.
A method for adjusting the frequency of a surface acoustic wave element 11 characterized in that a silicon oxide film 12 is laminated on a silicon dioxide film 6 by an electron beam evaporation method in the surface acoustic wave element 11 laminated with lithium tantalate. A drive electrode 4 and a reflective electrode 5 are formed on a substrate 3 cut out from a Y plate rotated 36 degrees around the X axis of a single crystal in the Z axis direction, and a refractive index of 1.46± is formed on the substrate 3 by plasma CVD. A surface acoustic wave element 21 having a laminated silicon dioxide film 6 of 0.01 nitride, characterized in that the surface layer 16 of the silicon dioxide film 6 is removed by plasma etching using carbon tetrafluoride. This is a frequency adjustment method.
３６°Ｙ ＸＬｉＴａＯ３板を伝播する音速をｖＩ、
屈折率が１．４６±０．Ｏｌの二酸化シリコン膜を伝播
する音速をｖｚ、電子ビーム薫着法による酸化シリコン
膜を伝播する音速をｖ３としたとき、それらの音速間に
は
ＶＩ＞Ｖ２＞Ｖ、！
の関係が成立する。36°Y The speed of sound propagating through the XLiTaO3 plate is vI,
The refractive index is 1.46±0. When the speed of sound propagating through the silicon dioxide film of Ol is vz, and the speed of sound propagating through the silicon oxide film formed by the electron beam smoke method is v3, the relationship between these sound speeds is VI>V2>V! The relationship holds true.
従って、３６ ’ Ｙ −Ｘ ＬｉＴａＯ３仮より切り
出した基板の表面に電極を形成し、その上に二酸化シリ
コン膜を積層させると、該電極に適当な電流を印加して
発生する弾性表面波の速度は、二酸化シリコン膜を積層
しないものより遅くなり、該二酸化シリコン膜の上に酸
化シリコン膜を積層した素子の弾性表面波は、さらに遅
くなる。そこで、発振周波数が所望値より高（なるよう
に、二酸化シリコン膜、酸化シリコン膜の積層された弾
性表面波素子は、酸化シリコン膜の表層部を除去するこ
とによって、発振周波数を所望値に調整可能である。Therefore, if an electrode is formed on the surface of a substrate cut out from a temporary 36' Y - , the surface acoustic waves of an element in which a silicon oxide film is laminated on the silicon dioxide film are slower than those in which a silicon dioxide film is not laminated. Therefore, the oscillation frequency is adjusted to the desired value by removing the surface layer of the silicon oxide film, so that the oscillation frequency is higher than the desired value. It is possible.
さらに、発振周波数が所望値より低くなるように、二酸
化シリコン膜の積層された弾性表面波素子は、二酸化シ
リコン膜の表層部を除去することによって、発振周波数
を所望値に調整可能である。Further, in a surface acoustic wave element in which silicon dioxide films are stacked, the oscillation frequency can be adjusted to a desired value by removing the surface layer portion of the silicon dioxide film so that the oscillation frequency is lower than the desired value.
以下に、図面を用いて本発明による弾性表面波素子の周
波数調整方法を説明する。Below, a method for adjusting the frequency of a surface acoustic wave element according to the present invention will be explained using the drawings.
第１図は本発明の第１の実施例による弾性表面波素子の
模式断面図、第２図は第１図に示す実施例において酸化
シリコン膜の厚さと発振周波数との関係を示す図、第３
図は本発明の第２の実施例による弾性表面波素子の模式
断面図、第４図は第３図に示す実施例においてエツチン
グ時間と周波数の変化率との関係を示す図である。FIG. 1 is a schematic cross-sectional view of a surface acoustic wave device according to a first embodiment of the present invention, FIG. 2 is a diagram showing the relationship between the thickness of the silicon oxide film and the oscillation frequency in the embodiment shown in FIG. 1, and FIG. 3
This figure is a schematic cross-sectional view of a surface acoustic wave device according to a second embodiment of the present invention, and FIG. 4 is a diagram showing the relationship between etching time and frequency change rate in the embodiment shown in FIG. 3.
第１図において、弾性表面波素子１１は３６°Ｙ−ＸＬ
ｉＴａ□ｚ仮より切り出した圧電体３の上面の中央に駆
動電極４を形成し、駆動電極４の左方および右方位置に
反射電極５を形成し、その上に屈折率が１．４６±０．
０１の二酸化シリコン（Ｓｉ Ｏｚ）膜６をプラズマＣ
ＶＤにより積層し、その上にＮ子ビーム蒸着法によって
酸化シリコン（ＳｉＯｘ）膜１２を適当な厚さに積層し
周波数調整したものである。In FIG. 1, the surface acoustic wave element 11 is 36°Y-XL.
A drive electrode 4 is formed at the center of the upper surface of the piezoelectric body 3 cut out from iTa□z temporary material, and reflective electrodes 5 are formed on the left and right positions of the drive electrode 4, and the refractive index is 1.46±. 0.
The silicon dioxide (SiOz) film 6 of No. 01 was exposed to plasma C.
A silicon oxide (SiOx) film 12 is laminated to an appropriate thickness by an N-beam evaporation method on top of the VD layer, and the frequency is adjusted.
第２図において、横軸はＳｉＯｘ膜１２の厚さ（Ａ）縦
軸は素子１１の発振周波数（ＭＨｚ）であり、測定に使
用した素子１１は、厚さ３．７５μｍに積層させたＳｉ
Ｏ□膜６の上に、ＳｉＯｘ膜１２を積層したものであり
、例えば厚さ２０００人のＳｉＯｘ膜１２を積層した素
子１１の発振周波数は、ＳｉＯｘ膜１２を積層する前よ
り約１．３６ＭＨｚだけ低下するようになる。In FIG. 2, the horizontal axis is the thickness (A) of the SiOx film 12, and the vertical axis is the oscillation frequency (MHz) of the element 11.
A SiOx film 12 is laminated on the O□ film 6. For example, the oscillation frequency of the element 11 in which the SiOx film 12 is laminated to a thickness of 2000 MHz is about 1.36 MHz lower than that before the SiOx film 12 is laminated. begins to decline.
そこで、第２図より素子１１の発振周波数を例えば１７
７ＭＨ７にしようとするときは、厚さ１５００人のＳｉ
Ｏｘ膜１２を積層すればよいことになる。Therefore, from FIG. 2, the oscillation frequency of the element 11 is set to 17, for example.
When trying to make 7MH7, Si with a thickness of 1500
All that is required is to stack the Ox film 12.
第３図において、弾性表面波素子２１は３６６Ｙ −Ｘ
ＬｉＴａＯｔ板より切り出した圧電体３の上面の中央に
駆動電極４を形成し、駆動電極４の左方および右方位置
に反射電極５を形成し、その上に屈折率が１．４６±０
．０１の二酸化シリコン（ＳｉＯｚ）膜６をプラズマＣ
ＶＤにより積層したのち、一般にアルミニウム（Ａ６）
にてなる電極４の表呈部および、電極４を測定系に接続
するＡｌワイヤを腐食させないため四フッ化炭素（ＣＨ
４）または、適量の酸素ガス（０２）を含むＣＩ（４の
雰囲気中に高周波電界を印加したプラズマエツチングに
よって、ＳｉＯ２膜６０膜層０表層部１６だけ除去する
ことで周波数調整したものである。In FIG. 3, the surface acoustic wave element 21 is 366Y -X
A driving electrode 4 is formed in the center of the upper surface of the piezoelectric body 3 cut out from a LiTaOt plate, and reflective electrodes 5 are formed on the left and right positions of the driving electrode 4, and on top of the reflecting electrode 5, the refractive index is 1.46±0.
．． The silicon dioxide (SiOz) film 6 of No. 01 is exposed to plasma C.
After lamination by VD, generally aluminum (A6)
Carbon tetrafluoride (CH
4) Alternatively, the frequency is adjusted by removing only the surface layer 16 of the SiO2 film 60 film layer 0 by plasma etching in which a high frequency electric field is applied in an atmosphere of CI (4) containing an appropriate amount of oxygen gas (02).
第４図において、横軸はエツチング時間（ｍｉｎ）。In FIG. 4, the horizontal axis represents etching time (min).
縦軸は素子２１の発振周波数の変化率（％）であり、５
ｉ０２ｎ莫６のエツチング条件を下記の表の如く試料表
１〜３について設定したとき、測定値をプロットしそれ
を実線で結んだ試料１．同プロットを破線で結んだ試料
２．同プロットを一点鎖線で結んだ試料３は、エツチン
グ条件（パワー）の差異によってエツチング速度が異な
り、エツチング時間に対し発振周波数の変化率は直線的
に変化（増加）する。The vertical axis is the rate of change (%) of the oscillation frequency of the element 21, and 5
When the etching conditions for i02nMo6 were set for sample tables 1 to 3 as shown in the table below, the measured values were plotted and connected with a solid line for sample 1. Sample 2, which connects the same plot with a broken line. Sample 3, whose plots are connected by a dashed line, has different etching speeds depending on the etching conditions (power), and the rate of change in the oscillation frequency changes (increases) linearly with respect to the etching time.
第５図は本発明の第３の実施例として、前記第１の実施
例におけるＳｉＯｘ膜に替えて五酸化タンタル（Ｔａｘ
ｅｓ）膜を蒸着したとき、該Ｔａ２’ｓ Ｍ！、の厚さ
と発振周波数の変化率との関係を示す図である。FIG. 5 shows a third embodiment of the present invention in which tantalum pentoxide (Tax) is used instead of the SiOx film in the first embodiment.
es) When the film is deposited, the Ta2's M! FIG. 3 is a diagram showing the relationship between the thickness of , and the rate of change in oscillation frequency.
第５図において、厚さ５０人のＴａｘｅｓ膜を被着し発
振周波数ｆｏ＝１７５．７５ＭＨｚまたは１７６．０４
ＭＨｚとした弾性表面波素子は、周波数変化率が−０，
２９％程度であるのに対し、厚さ１００人のＴａｚ０５
膜を被着し発振周波数ｆ ｏ ” １７５．９８ Ｍ
Ｈｚまたは１７５．７６ＭＨｚとした弾性表面波素子は
、周波数変化率が−０，５８％程度となる。In Fig. 5, the oscillation frequency fo = 175.75 MHz or 176.04 when a 50-thick Taxes film is applied.
MHz, the surface acoustic wave element has a frequency change rate of -0,
Taz05 with a thickness of 100 people is about 29%
After coating the film, the oscillation frequency f o ” 175.98 M
A surface acoustic wave element set to Hz or 175.76 MHz has a frequency change rate of about -0.58%.
第６図は本発明の第４の実施例として、前記第１の実施
例におけるＳｉＯｘ膜に替えて窒化シリコン（Ｓｉ３Ｎ
ｎ）を蒸着したとき、該Ｓｉ３Ｎ４膜の厚さと発振周波
数の変化率との関係を示す図である。FIG. 6 shows a fourth embodiment of the present invention in which silicon nitride (Si3N) is used instead of the SiOx film in the first embodiment.
FIG. 4 is a diagram showing the relationship between the thickness of the Si3N4 film and the rate of change in the oscillation frequency when Si3N4 is deposited.
第６図において、厚さ１８００人のＳｉ＋Ｎａ膜を被着
し発振周波数ｆｏ＝１７５．８８ＭＨｚまたは１７６．
２３ＭＩ（ｚとした弾性表面波素子は、周波数変化率が
一〇、６７％程度であるのに対し、厚さ３０００人のＳ
ｔ、Ｎ、膜を被着し発振周波数ｆ ｏ ＝ １７６、３
３ Ｍ Ｈｚまたは１７５．８６ＭＨｚとした弾性表面
波素子は、周波数変化率が−１，１％程度となる。In FIG. 6, a Si+Na film with a thickness of 1800 mm is deposited and the oscillation frequency fo=175.88 MHz or 176.8 MHz.
The surface acoustic wave element with 23MI (z) has a frequency change rate of about 10.67%, whereas the surface acoustic wave element with a thickness of 3000 people
t, N, film deposited, oscillation frequency f o = 176, 3
A surface acoustic wave element with a frequency of 3 MHz or 175.86 MHz has a frequency change rate of about -1.1%.
以上説明したように本発明方法によれば、電極のパター
ン形状と無関係にＳｉＯｘ膜、Ｔａｚ０５膜、Ｓｉ、Ｎ
４膜を適当な厚さに例えば発振周波数を測定しなから被
着させるまたは、前以て被着したＳｉＯ□膜を適当な厚
さとなるように除去することで周波数調整するため、特
に高周波素子の生産性に優れ微調整を可能止した効果が
ある。As explained above, according to the method of the present invention, SiOx film, Taz05 film, Si, N
4 film to an appropriate thickness, for example, by depositing the oscillation frequency without measuring it, or by removing the pre-deposited SiO□ film to an appropriate thickness, the frequency can be adjusted, especially for high-frequency devices. This has the effect of improving productivity and making fine adjustments possible.
第１図は本発明の第１の実施例による弾性表面波素子の
模式断面図、
第２回は第１図に示す酸化シリコン膜の厚さと発振周波
数との関係を示す図、
第３図は本発明の第２の実施例による弾性表面波素子の
模式断面図、
第４図は第３図に示す実施例において二酸化シリコン膜
のエツチング時間と発振周波数の変化率との関係を示す
図、
第５図は本発明の第３の実施例におけるＴａ２ｅｓ膜の
厚さと発振周波数の変化率との関係を示す図、
第６図は本発明の第４の実施例におけるＳｉ３Ｎ４膜の
厚さと発振周波数の変化率との関係を示す図、
第７図は弾性表面波素子の概略構成を示す図、第８図は
３６°Ｙ −Ｘ ＬｉＴａＯ３板の説明図、である。
図中において、
■は３６ ’ Ｙ Ｘ ＬｉＴａ０．仮、３は素子基
板、
４．５は電極、
６は二酸化シリコン膜、
１１．２１は弾性表面波素子、
１６は二酸化シリコン膜の表層部、
を示す。
第
ず
口
第
霞
第
（口９
弾性表面波素子の周波数調整方法
３、補正をする者
事件との関係 特許出願人
住所 神奈川県用崎市中原区上小田中１０１５番地名称
（５２２）富士通株式会社
代表者 山 本 卓 眞
４、代理人 郵便番号 ２１１
住所 神奈川県用崎市中原区上小田中１０１５番地（イ
） （コノ３６’Ｙ−
ＸＬｉＴ４０３板のａｌ’Ｆ口第 ｇ 図
５、補正により増加する発明の数
補正命令の日付
羊＝嚇罎辛→−一
粘＝ヰ≠障青合
なし
７、補正の対象
（１）明細書の「発明の詳細な説明」の欄（２）図面の
（第８図）
８、補正の内容
（１）明細書の第１０頁第６行目と第７行目に記載のｒ
ＣＨ，ＪをｒｃＦ、Ｊと補正する。
（２）明細書の第１０頁第１５行目に表中に記載の「シ
ラン流量」をｒＣＦ、流量」と補正する。
（３） 図面第８図を別紙の通り補正する。
９、添付書類の目録
（１）補正図面
（イン
Ｘ軸
（ロ）
３６’ Ｙ−ＸＬＩＴａθＪ 叔／ｌ ＭＬ明門口 ６
図FIG. 1 is a schematic cross-sectional view of a surface acoustic wave device according to the first embodiment of the present invention, the second is a diagram showing the relationship between the thickness of the silicon oxide film shown in FIG. 1 and the oscillation frequency, and FIG. A schematic cross-sectional view of a surface acoustic wave device according to a second embodiment of the present invention; FIG. 4 is a diagram showing the relationship between the etching time of the silicon dioxide film and the rate of change in the oscillation frequency in the embodiment shown in FIG. Figure 5 shows the relationship between the thickness of the Ta2es film and the rate of change in the oscillation frequency in the third embodiment of the present invention, and Figure 6 shows the relationship between the thickness of the Si3N4 film and the rate of change in the oscillation frequency in the fourth embodiment of the invention. FIG. 7 is a diagram showing a schematic configuration of a surface acoustic wave element, and FIG. 8 is an explanatory diagram of a 36°Y-X LiTaO3 plate. In the figure, ■ is 36' Y X LiTa0. 3 is an element substrate, 4.5 is an electrode, 6 is a silicon dioxide film, 11.21 is a surface acoustic wave element, and 16 is a surface layer of the silicon dioxide film. No. 1 Kasumi No. 9 Frequency adjustment method for surface acoustic wave elements 3, relationship with the case of the person making the correction Patent applicant address 1015 Kamiodanaka, Nakahara-ku, Yozaki City, Kanagawa Prefecture Name (522) Representative of Fujitsu Limited Person Takashi Yamamoto 4, Agent Postal code 211 Address 1015 Kamiodanaka, Nakahara-ku, Yozaki-shi, Kanagawa (I) (Kono 36'Y-
Figure 5. Number of inventions increased by amendment. Date of amendment order. "Detailed Description of the Invention" column (2) Drawing (Figure 8) 8. Contents of amendment (1) r stated in lines 6 and 7 of page 10 of the specification
Correct CH,J with rcF,J. (2) The "silane flow rate" listed in the table on page 10, line 15 of the specification is corrected to "rCF, flow rate." (3) Figure 8 of the drawing will be corrected as shown in the attached sheet. 9. List of attached documents (1) Corrected drawings (in
figure
Claims (2)
向へ３６度回転させたＹ板から切り出した基板（３）上
に電極（４，５）を形成し、その上にプラズマＣＶＤに
より屈折率が１．４６±０．０１の二酸化シリコン膜（
６）を積層した弾性表面波素子において、該二酸化シリ
コン膜（６）の上に、電子ビーム蒸着法によって酸化シ
リコン膜（１２）または五酸化タンタル膜あるいは窒化
シリコン膜を積層することを特徴とした弾性表面波素子
の周波数調整方法。(1) Electrodes (4, 5) are formed on a substrate (3) cut out from a Y plate that has been rotated 36 degrees around the X-axis of a lithium tantalate single crystal in the Z-axis direction, and the electrodes (4, 5) are formed on the substrate by plasma CVD. Silicon dioxide film with a ratio of 1.46±0.01 (
6) is characterized in that a silicon oxide film (12), a tantalum pentoxide film, or a silicon nitride film is laminated on the silicon dioxide film (6) by an electron beam evaporation method. Frequency adjustment method for surface acoustic wave elements.
向へ３６度回転させたＹ板から切り出した基板（３）上
に電極（４，５）を形成し、その上にプラズマＣＶＤに
より屈折率が１．４６±０．０１の二酸化シリコン膜（
６）を積層した弾性表面波素子において、四フッ化炭素
を用いたプラズマエッチングにより、前記二酸化シリコ
ン膜（６）の表層部（１６）を除去することを特徴とし
た弾性表面波素子の周波数調整方法。(2) Electrodes (4, 5) are formed on the substrate (3) cut out from a Y plate that has been rotated 36 degrees around the X-axis in the Z-axis direction of a lithium tantalate single crystal, and the electrodes (4, 5) are formed on the substrate by plasma CVD. Silicon dioxide film with a ratio of 1.46±0.01 (
6) Frequency adjustment of a surface acoustic wave device, characterized in that in the surface acoustic wave device laminated, the surface layer portion (16) of the silicon dioxide film (6) is removed by plasma etching using carbon tetrafluoride. Method.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63187704A JPH0748626B2 (en) | 1988-07-27 | 1988-07-27 | Frequency adjustment method for surface acoustic wave device |
| US07/384,829 US4978879A (en) | 1988-07-27 | 1989-07-25 | Acoustic surface wave element |
| DE68921811T DE68921811T2 (en) | 1988-07-27 | 1989-07-27 | Surface acoustic wave arrangements. |
| EP89307660A EP0353073B1 (en) | 1988-07-27 | 1989-07-27 | Acoustic surface wave devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63187704A JPH0748626B2 (en) | 1988-07-27 | 1988-07-27 | Frequency adjustment method for surface acoustic wave device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0236608A true JPH0236608A (en) | 1990-02-06 |
| JPH0748626B2 JPH0748626B2 (en) | 1995-05-24 |
Family
ID=16210703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63187704A Expired - Fee Related JPH0748626B2 (en) | 1988-07-27 | 1988-07-27 | Frequency adjustment method for surface acoustic wave device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0748626B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04258008A (en) * | 1991-02-12 | 1992-09-14 | Murata Mfg Co Ltd | Surface acoustic wave device |
| JP2006513649A (en) * | 2003-01-23 | 2006-04-20 | エプコス アクチエンゲゼルシャフト | SAW device having improved temperature characteristics |
| US7322093B2 (en) | 2004-03-29 | 2008-01-29 | Murata Manufacturing Co., Ltd. | Method for producing a boundary acoustic wave device |
| US7327071B2 (en) | 2004-03-02 | 2008-02-05 | Murata Manufacturing Co., Ltd. | Surface acoustic wave device |
| JP2010045752A (en) * | 2008-08-12 | 2010-02-25 | Tatung Univ | High frequency surface acoustic wave device and substrate thereof |
| US8553391B2 (en) | 2010-09-16 | 2013-10-08 | Murata Manufacturing Co., Ltd. | Electronic component |
| CN115781946A (en) * | 2022-11-29 | 2023-03-14 | 山东大学 | Compression type high-temperature piezoelectric sensitive cutting type of lithium niobate crystal, preparation and application |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS555924A (en) * | 1978-06-27 | 1980-01-17 | Ito Kogaku Kogyo Kk | Composition for coating formed plastic material |
| JPS5833310A (en) * | 1981-08-21 | 1983-02-26 | Hitachi Ltd | Surface acoustic wave device |
| JPS6177407A (en) * | 1984-09-22 | 1986-04-21 | Japan Radio Co Ltd | Manufacture of layered structure surface acoustic wave element |
-
1988
- 1988-07-27 JP JP63187704A patent/JPH0748626B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS555924A (en) * | 1978-06-27 | 1980-01-17 | Ito Kogaku Kogyo Kk | Composition for coating formed plastic material |
| JPS5833310A (en) * | 1981-08-21 | 1983-02-26 | Hitachi Ltd | Surface acoustic wave device |
| JPS6177407A (en) * | 1984-09-22 | 1986-04-21 | Japan Radio Co Ltd | Manufacture of layered structure surface acoustic wave element |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04258008A (en) * | 1991-02-12 | 1992-09-14 | Murata Mfg Co Ltd | Surface acoustic wave device |
| JP2006513649A (en) * | 2003-01-23 | 2006-04-20 | エプコス アクチエンゲゼルシャフト | SAW device having improved temperature characteristics |
| US7327071B2 (en) | 2004-03-02 | 2008-02-05 | Murata Manufacturing Co., Ltd. | Surface acoustic wave device |
| US7322093B2 (en) | 2004-03-29 | 2008-01-29 | Murata Manufacturing Co., Ltd. | Method for producing a boundary acoustic wave device |
| EP2383888A3 (en) * | 2004-03-29 | 2012-08-01 | Murata Manufacturing Co., Ltd. | Boundary acoustic wave device manufacturing method and boundary acoustic wave device |
| JP2010045752A (en) * | 2008-08-12 | 2010-02-25 | Tatung Univ | High frequency surface acoustic wave device and substrate thereof |
| US8553391B2 (en) | 2010-09-16 | 2013-10-08 | Murata Manufacturing Co., Ltd. | Electronic component |
| CN115781946A (en) * | 2022-11-29 | 2023-03-14 | 山东大学 | Compression type high-temperature piezoelectric sensitive cutting type of lithium niobate crystal, preparation and application |
| CN115781946B (en) * | 2022-11-29 | 2024-06-04 | 山东大学 | Compression type high-temperature piezoelectric sensitive cutting type lithium niobate crystal, preparation and application |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0748626B2 (en) | 1995-05-24 |
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