JPS63177605A - Piezoelectric thin film resonator - Google Patents
Piezoelectric thin film resonatorInfo
- Publication number
- JPS63177605A JPS63177605A JP825687A JP825687A JPS63177605A JP S63177605 A JPS63177605 A JP S63177605A JP 825687 A JP825687 A JP 825687A JP 825687 A JP825687 A JP 825687A JP S63177605 A JPS63177605 A JP S63177605A
- Authority
- JP
- Japan
- Prior art keywords
- protective film
- thin film
- piezoelectric thin
- substrate
- void layer
- 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
- 239000010409 thin film Substances 0.000 title claims description 52
- 230000001681 protective effect Effects 0.000 claims abstract description 46
- 239000000758 substrate Substances 0.000 claims abstract description 33
- 239000010408 film Substances 0.000 claims description 65
- 239000011800 void material Substances 0.000 claims description 55
- 239000010410 layer Substances 0.000 description 59
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 36
- 239000011787 zinc oxide Substances 0.000 description 18
- 229910052751 metal Inorganic materials 0.000 description 11
- 239000002184 metal Substances 0.000 description 11
- 239000004065 semiconductor Substances 0.000 description 11
- 238000000034 method Methods 0.000 description 9
- 238000000605 extraction Methods 0.000 description 8
- 238000005530 etching Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 238000009792 diffusion process Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- QTBSBXVTEAMEQO-UHFFFAOYSA-N acetic acid Substances CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 4
- 210000004379 membrane Anatomy 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 239000012778 molding material Substances 0.000 description 3
- 230000010355 oscillation Effects 0.000 description 3
- 238000004544 sputter deposition Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052789 astatine Inorganic materials 0.000 description 1
- 210000002469 basement membrane Anatomy 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の目的〕
（産業上の利用分野）
この発明は、高周波発振器等に用いられる圧電薄膜共振
子ｌこ関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a piezoelectric thin film resonator used in a high frequency oscillator or the like.
（従来の技術）
従来、高周波発振器の発振源等に用いる共振子として第
４図に示すような圧電薄膜共振子が考案されている。こ
の共振子は、基板１上に形成され上へ順に下部保護膜２
．下部電極６．圧電体５゜上部電極７．上部保護膜３に
より構成されている。(Prior Art) Conventionally, a piezoelectric thin film resonator as shown in FIG. 4 has been devised as a resonator used as an oscillation source of a high frequency oscillator. This resonator is formed on a substrate 1 and sequentially extends upward into a lower protective film 2.
．． Lower electrode 6. Piezoelectric body 5° upper electrode 7. It is composed of an upper protective film 3.
そして、圧電体５が上下に振動することにより上部電極
７と下部電極６との間にその振動周波数による電気信号
が得られる。圧電体５が上下に振動する際上部保護膜３
．下部保獲膜２．上部電極７゜下部電極６も同様に振動
するが、下方向へ振動した時に下部保護膜２が基板１に
接触しないように。Then, as the piezoelectric body 5 vibrates up and down, an electric signal is obtained between the upper electrode 7 and the lower electrode 6 based on the vibration frequency. When the piezoelectric body 5 vibrates up and down, the upper protective film 3
．． Lower retentive membrane 2. The upper electrode 7° and the lower electrode 6 vibrate in the same way, but in such a way that the lower protective film 2 does not come into contact with the substrate 1 when vibrating downward.
下部保護膜２と基板ｌとの間には空隙層８が設けられて
いる。なお、圧電体５が撮動するのはこの空隙層８の上
部１こおいてであり、上記振動周波数は空隙層８上部の
圧電体５％上部保鏝膜３．下部保護膜２．上部電極７．
下部電極６の総和の厚みによりきまる。A void layer 8 is provided between the lower protective film 2 and the substrate l. It should be noted that the piezoelectric body 5 takes an image at the upper part 1 of the void layer 8, and the above-mentioned vibration frequency is the same as that of the piezoelectric body 5% upper retaining film 3. Lower protective film 2. Upper electrode7.
It is determined by the total thickness of the lower electrodes 6.
このように構成された圧電薄膜共振子は任意の基板ｌの
上に形成できるため、集積回路が形成された半導体基板
上にも形成することができるという特徴をもっている。Since the piezoelectric thin film resonator configured in this manner can be formed on any substrate l, it has the characteristic that it can also be formed on a semiconductor substrate on which an integrated circuit is formed.
このことにより、たとえば発振回路とこの圧電薄膜共振
子を同一の半導体基板上に形成して１発振器の超小形化
を図ることが可能である。This makes it possible, for example, to form an oscillation circuit and this piezoelectric thin film resonator on the same semiconductor substrate, thereby achieving ultra-miniaturization of one oscillator.
しかし、このような圧電薄膜共振子は上記のようにその
厚みにより振動周波数がきまるため上部に異物が付着す
ると振動周波数が変化してしまう。However, as described above, the vibration frequency of such a piezoelectric thin film resonator is determined by its thickness, so if foreign matter adheres to the top, the vibration frequency will change.
そのため、なんらかのケースに密封しなければならない
。ところが、現在集積回路に多用されているモールドは
このような圧電薄膜共振子には使用できない。なぜなら
、モールド材が圧電薄膜共振子上部に充てんされると、
共振子が振動できなくなり、所定の電気的特性が得られ
なくなるからである。Therefore, it must be sealed in some kind of case. However, the molds currently commonly used for integrated circuits cannot be used for such piezoelectric thin film resonators. This is because when the molding material is filled on the top of the piezoelectric thin film resonator,
This is because the resonator becomes unable to vibrate and predetermined electrical characteristics cannot be obtained.
（発明が解決しようとする問題点）
上記のように従来の圧電薄膜共振子は上部に異物が付着
するとその振動周波数が変化してしまうことと、モール
ドできないという問題点があった。(Problems to be Solved by the Invention) As described above, the conventional piezoelectric thin film resonator has the problems that the vibration frequency changes when foreign matter adheres to the upper part and that it cannot be molded.
この発明の目的は上記の問題点を解決し、上部に異物が
付着しても振動周波数が変化せず、さらにはモールドし
たとしても電気的特性が変化せず所定の性能が得られる
圧電薄膜共振子を提供しようとするものである。The purpose of this invention is to solve the above-mentioned problems, and to create a piezoelectric thin film resonator that does not change the vibration frequency even if foreign matter adheres to the upper part, and furthermore, does not change the electrical characteristics even when molded and provides the desired performance. It is intended to provide a child.
ｃ問題点を解決するための手段）
この発明は、圧電れγ膜共振子の振動部上部すなわち基
板と反対側の面に上部空隙層を設け、さらにその上に上
部空隙層保護膜を設けたものである。c) Means for Solving Problems) This invention provides an upper void layer above the vibrating part of a piezoelectric gamma film resonator, that is, on the surface opposite to the substrate, and further provides an upper void layer protective film thereon. It is something.
（作用）
この発明によれば、振動部すなわち圧電体、上部電極、
下部電極、上部保獲膜、下部保護膜は祈たに設けられた
上部空隙層と下部空隙層との間で振動し、その振動周波
数はこれら振動部の総和の厚みによってきまる。上部空
隙層保護膜には上部空隙層によって圧電体の振動はつた
わらず上記倣動周波数には影響をあたえない。よって、
最上部にある上部空隙層保護膜に異物が付着したとして
も、圧電薄膜共振子としての電気的特性は変化しない。(Function) According to the present invention, the vibrating part, that is, the piezoelectric body, the upper electrode,
The lower electrode, the upper retention film, and the lower protective film vibrate between the upper void layer and the lower void layer provided in the prayer, and the vibration frequency is determined by the total thickness of these vibrating parts. The vibration of the piezoelectric body is not transmitted to the upper void layer protection film due to the upper void layer and does not affect the above-mentioned vibration frequency. Therefore,
Even if foreign matter adheres to the upper void layer protective film at the top, the electrical characteristics of the piezoelectric thin film resonator do not change.
（実施例）
以下１図面を参照してこの発明の実施例について説明す
る。(Example) An example of the present invention will be described below with reference to one drawing.
第１図はこの発明の一実施例に係る圧電＃膜共振子の構
成を示すものである。この共振子は、基板１上に形成さ
れ、上へ順に、下部保護膜２．下部電極６．圧電体５．
上部＊＠７．上部保Ｊ膜３゜上部空隙層保護膜４により
構成されている。そして、基板１と下部保護膜２との間
には下部空隙層８が、下部保護膜３と上部空隙層保護膜
４との間には上部空隙層９がそれぞれ設けられている。FIG. 1 shows the structure of a piezoelectric membrane resonator according to an embodiment of the present invention. This resonator is formed on a substrate 1, and in order from above, a lower protective film 2. Lower electrode 6. Piezoelectric body 5.
Top *@7. It is composed of an upper J-retaining film 3° and an upper void layer protective film 4. A lower void layer 8 is provided between the substrate 1 and the lower protective film 2, and an upper void layer 9 is provided between the lower protective film 3 and the upper void layer protective film 4.
この空隙層８は下部保護膜２が下へ振動した時に基板１
に接触しない厚さに、空隙層９は下部保護膜３が上へ振
動した時に上部空隙層保護膜４に接触しない厚さにそれ
ぞれ選定されている。When the lower protective film 2 vibrates downward, this void layer 8 causes the substrate 1 to
The thickness of the void layer 9 is selected to be such that it does not contact the upper void layer protective film 4 when the lower protective film 3 vibrates upward.
この圧電薄膜共振子は圧電体５の上部空隙層９と下部空
隙層８との間の部分が上下に振動することにより、上部
電極７と下部電極６との間にその振動周波数による電気
信号が得られるが、圧電体５が振動する際、上部電極７
．下部電極６．上部保護膜３．下部保護膜２も上部空隙
層９と下部空隙層８との間で振動する。このため上記振
動周波数はこれら振動部分すなわち上部保護Ｍ３、上部
電極７．圧電体５．下部電極６．下部保護膜２の。In this piezoelectric thin film resonator, the part between the upper gap layer 9 and the lower gap layer 8 of the piezoelectric body 5 vibrates vertically, so that an electric signal is generated between the upper electrode 7 and the lower electrode 6 due to the vibration frequency. However, when the piezoelectric body 5 vibrates, the upper electrode 7
．． Lower electrode 6. Upper protective film 3. The lower protective film 2 also vibrates between the upper void layer 9 and the lower void layer 8. For this reason, the above-mentioned vibration frequency is determined by these vibration parts, namely the upper protection M3, the upper electrode 7. Piezoelectric body 5. Lower electrode 6. of the lower protective film 2.
上部空隙層９と下部空隙層８との間の部分の総和の厚み
によりきまる。上部空隙層保護膜４は上部空隙層９があ
るため圧電体５の振動がつたわらず振動しないため、上
記振動周波数には影響しない。It is determined by the total thickness of the portion between the upper void layer 9 and the lower void layer 8. Since the upper void layer protection film 4 has the upper void layer 9, the vibrations of the piezoelectric body 5 are not transmitted and do not vibrate, so that it does not affect the above-mentioned vibration frequency.
次に、第１図の構成の圧電薄膜共振子を得るための工程
を第２図に示す。まず、第４図に示した従来の圧電薄膜
共振子を形成し、その上部に第２図（１）に示すように
酸化亜鉛等により上部空隙層となる埋込み層１０を形成
する。さらに、その上に第２図（ＩＩ）に示すように２
酸化シリコン等による上部空隙層保護膜４を形成する。Next, FIG. 2 shows a process for obtaining a piezoelectric thin film resonator having the configuration shown in FIG. 1. First, a conventional piezoelectric thin film resonator shown in FIG. 4 is formed, and a buried layer 10, which becomes an upper gap layer, made of zinc oxide or the like is formed on top of the piezoelectric thin film resonator as shown in FIG. 2(1). Furthermore, as shown in FIG. 2 (II),
An upper void layer protective film 4 made of silicon oxide or the like is formed.
次に％第２図（ｉｉｉ）に示すように上部空隙層保護膜
４に埋込み層１０まで１つまたは複数の穴をエツチング
等によりあける。この際基板１上の上部空隙層保護膜４
の不要部分を同時に取除く。そして第２図（１■）に示
すようにこの穴からエツチングにより埋込み層ｌＯを取
除き、上部空隙層９を形成する。以上のような工程によ
り第１図に示した圧電薄膜共振子が得られるわけである
。このような工程によれば、全ての作業が基板１の上面
からおこなえるという特徴がある。Next, as shown in FIG. 2(iii), one or more holes are made in the upper void layer protective film 4 up to the buried layer 10 by etching or the like. At this time, the upper void layer protective film 4 on the substrate 1
Remove unnecessary parts at the same time. Then, as shown in FIG. 2 (1), the buried layer 1O is removed from this hole by etching to form an upper void layer 9. Through the steps described above, the piezoelectric thin film resonator shown in FIG. 1 can be obtained. This process has the feature that all operations can be performed from the top surface of the substrate 1.
このようにして得られた図１に示す圧電薄膜共振子は、
上部空隙層９と下部空隙層８の間の振動部が上部空隙層
保護膜４と基板１により保護されるため、異物が付着し
ても振動周波数は変化しない。なお、上部空隙層保護膜
４には上部空隙層９を形成するための穴がおいているが
、モールド材はエツチング液に比べて十分粘性が高いた
め上部空隙層９に進入することはない。よってこの圧電
薄膜共振子をモールドしても電気的特性が変化すること
はない。The piezoelectric thin film resonator shown in FIG. 1 obtained in this way is
Since the vibrating portion between the upper void layer 9 and the lower void layer 8 is protected by the upper void layer protective film 4 and the substrate 1, the vibration frequency does not change even if foreign matter adheres. Although the upper void layer protective film 4 has holes for forming the upper void layer 9, the molding material does not enter the upper void layer 9 because its viscosity is sufficiently higher than that of the etching solution. Therefore, even if this piezoelectric thin film resonator is molded, its electrical characteristics do not change.
この発明は上記の実施例、工程に限定されるものではな
く１種々に変形して実施できる。This invention is not limited to the above embodiments and steps, but can be implemented with various modifications.
たとえば、第３図に示す圧電薄膜共振子は、基板１を下
部から堀ることにより下部空隙層８を形成したものであ
る。この場合も、上部空隙層９は第２図に示した工程で
形成できる。この他、下部空隙層８は基板に溝を堀った
ものを使用することも可能である。For example, in the piezoelectric thin film resonator shown in FIG. 3, a lower void layer 8 is formed by excavating the substrate 1 from the bottom. In this case as well, the upper void layer 9 can be formed by the steps shown in FIG. In addition, it is also possible to use a substrate with grooves formed as the lower void layer 8.
また、第２図に示した工程では、従来と同様の圧電薄膜
共振子を形成した後、上部空隙層を形成したが、たとえ
ば、上部空隙層と下部空隙層とを同時に形成するこさも
可能である。その他％種々の工程により、この発明によ
る圧電薄膜共振子を得ることができる。Furthermore, in the process shown in Figure 2, the upper void layer was formed after forming the piezoelectric thin film resonator as in the conventional method, but it is also possible, for example, to form the upper void layer and the lower void layer at the same time. be. The piezoelectric thin film resonator according to the present invention can be obtained through various other processes.
さらに、上部空隙層保護膜４．埋込み層１０を形成する
材料についても、上記の２酸化シリコン。Furthermore, upper void layer protective film 4. The material for forming the buried layer 10 is also the silicon dioxide mentioned above.
酸化亜鉛に限定されるものではなく種々の材料が使用で
きる。It is not limited to zinc oxide, and various materials can be used.
また、必要に応じて上部保護膜３と下部保護膜２は省略
することが可能である。Further, the upper protective film 3 and the lower protective film 2 can be omitted if necessary.
そして、この発明による圧電薄膜共振子をモールドする
場合またはケースに密封する場合、エージング特性を改
善するためｌこ、上部空隙層及び下部空隙層を一度真空
状態し、その後にヘリウムやアルゴン、ガス等の不活性
ガスを充てんする不活性ガス等による置換を行うことが
可能である。ガス充てん後、モールドまたはケースに密
封するまでの間上部空隙層保護膜の穴から上部空隙層内
のガスが急激にもれることはないが、上記の穴にフタを
する等ガスをもれにくくする処置を講じてももちろんか
まわない。ガスを充てんしない場合でも上記のフタをす
ることにより低粘性のモールド材が上部空隙層に進入す
るのを防止することができる。When molding the piezoelectric thin film resonator according to the present invention or sealing it in a case, in order to improve aging characteristics, the upper and lower void layers are once placed in a vacuum state, and then helium, argon, gas, etc. It is possible to perform replacement with an inert gas, etc. by filling the inert gas. After gas filling, until the mold or case is sealed, the gas in the upper void layer will not suddenly leak from the holes in the upper void layer protective film, but the above holes should be covered to prevent gas from leaking. Of course, you may take measures to do so. Even when gas is not filled, by putting the above-mentioned lid on, it is possible to prevent the low-viscosity molding material from entering the upper void layer.
さらにまた、このような圧電薄膜共振子は、半導体集積
回路との一体化構造が考えられて（する。Furthermore, such a piezoelectric thin film resonator is considered to have an integrated structure with a semiconductor integrated circuit.
すなわち同一半導体基板上に、この共振子と半導体集積
回路とを一体化して形成し、例えばワンチップの発振器
等を構成すれば１回路の小形化、簡易化が図られる。こ
のように一体化構造をとる場合、半導体集積回路の接続
点とこの共振子の上下電極とをアルミニウム等の金属膜
による配線、Ｎ＋＋ターンで接続することが必要になる
。しかしな力Ｓらｒ出倶春 通常圧電薄膜は２〜１０μ
ｍ程ｅ（Ｄ厚さを有するためこの圧電薄膜の膜厚に相当
する段差により共振子の上部電極と半導体集積回路の接
続点とを接続する際配線用金属膜がリフトオフ法や金属
マスク法では十分に形成できず、断線などを生じやすい
という問題がある（なお、エツチング法は圧電薄膜（Ｚ
ｎＯ）がエツチング液に対して弱いので使用できない。In other words, if this resonator and a semiconductor integrated circuit are integrally formed on the same semiconductor substrate to form, for example, a one-chip oscillator, one circuit can be made smaller and simpler. When adopting such an integrated structure, it is necessary to connect the connection point of the semiconductor integrated circuit and the upper and lower electrodes of this resonator with wiring made of a metal film such as aluminum, or with an N++ turn. However, the force S is usually 2 to 10μ for piezoelectric thin films.
When connecting the upper electrode of the resonator and the connection point of the semiconductor integrated circuit with a step corresponding to the film thickness of this piezoelectric thin film, the wiring metal film has a thickness of approximately D. There is a problem that the etching method cannot be formed sufficiently and is prone to wire breakage.
nO) cannot be used because it is weak against etching solutions.
）。そこでこのような問題に対しては拡散用の金属によ
り接続すべき電極の対向する位置の圧電薄膜に導電性を
もたせて互いに電気的に接続するようにすることが望ま
しい。). Therefore, in order to solve this problem, it is desirable that the piezoelectric thin films at positions facing the electrodes to be connected to each other be electrically conductive so as to be electrically connected to each other using a diffusion metal.
第５図はこのような圧電薄膜共振子の配線構造の実施例
を示す斜視図であり第６図は第５図のＡＡｌにおける断
面図である。あらかじめ半導体集積回路が形成された基
板４１上にＣＶＤ法又はスパッタ法で８ｉ０＠膜４２．
４３を付着させ、その後裏面の所定の部分をＰＥＤ液（
パイロカテコール、エチレンジアミン、水の混合液）等
の異方性エツチング液で除去し凹部４４を形成して図に
示すような５ｉ４１．Ｓｔｏｗ ４２ からなる基底膜
を形成する。この基底膜上にＡｕ又はＡＡを主成分とす
る金属膜により第１の電極４５を形成する。次に半導体
集積回路側の電気接続用の窓５４をフォトリングライ技
術を用いて形成し配線電極５１を露出させる。その上に
スパッタ法又は蒸着法によってＡｔ等の金属を付着させ
配線電極５１を含むＳ ＋ Ｏｘ 膜上にフォトエツチ
ング法により所定の大きさの引き出し電極４６．４７を
形成する。引き出し電極４７は第１の電極４５と配線電
極５１を電気的接続し、引き出し電極４６は第２の電極
４９と電気的接続するためのものである。更にその上に
ＲＦマグネトロンスパッタ法等によりＺｎＯ圧電膜を付
着させ酢酸と水からなるエツチング液を用いて所定の大
きさに形成する。次にＺｎＯ膜をはさんで引き出し電極
４６の一部と対向する位置にＴｉ等の拡散金属を金属マ
スク法又はリフトオフ法によって所定の大きさで形成し
、更にその上にＡｕ等の金属膜により第２の電極４９を
第１の電極４５と直交する方向に所定の大きさで形成す
る。この場合圧電薄膜４８は基板４１の凹部４４に対応
した位置に形成され、８ｇ１の電極４５と第２の電極４
９はＺｎＯ圧電薄膜４８をはさんで少なくとも一部が互
いに対向して配置されている。さらに第２の電極の他端
は拡散金属ＺｎＯ圧電薄膜をはさんで引き出し電極４６
と対向して配置されている。最後にオーブン等により２
５０℃２時間３０分以上の熱処理を施しＺｎＯ圧電薄膜
４８中にＴｉを拡散させ、この拡散領域５０の圧電薄膜
に導電性をもたせ第２の電極４９と引き出し電極４６を
電気的接続させる。FIG. 5 is a perspective view showing an example of the wiring structure of such a piezoelectric thin film resonator, and FIG. 6 is a cross-sectional view in AAl of FIG. 5. An 8i0@ film 42. is deposited on a substrate 41 on which a semiconductor integrated circuit has been formed in advance by CVD or sputtering.
43, and then apply PED liquid (
5i41. A basement membrane consisting of Stow 42 is formed. A first electrode 45 is formed on this base film using a metal film mainly composed of Au or AA. Next, a window 54 for electrical connection on the semiconductor integrated circuit side is formed using photorin-grid technology to expose the wiring electrode 51. A metal such as At is deposited thereon by sputtering or vapor deposition, and extraction electrodes 46 and 47 of a predetermined size are formed on the S + Ox film including the wiring electrode 51 by photoetching. The extraction electrode 47 is for electrically connecting the first electrode 45 and the wiring electrode 51, and the extraction electrode 46 is for electrically connecting the second electrode 49. Furthermore, a ZnO piezoelectric film is deposited thereon by RF magnetron sputtering or the like and formed to a predetermined size using an etching solution consisting of acetic acid and water. Next, a diffused metal such as Ti is formed in a predetermined size by a metal mask method or a lift-off method at a position facing a part of the extraction electrode 46 across the ZnO film, and then a metal film such as Au is formed on top of the diffusion metal. A second electrode 49 is formed with a predetermined size in a direction perpendicular to the first electrode 45. In this case, the piezoelectric thin film 48 is formed at a position corresponding to the recess 44 of the substrate 41, and the 8g1 electrode 45 and the second electrode 4
9 are arranged so that at least a portion thereof faces each other with the ZnO piezoelectric thin film 48 in between. Furthermore, the other end of the second electrode is an extraction electrode 46 with a diffusion metal ZnO piezoelectric thin film in between.
is placed opposite. Finally, put it in the oven etc. 2
A heat treatment is performed at 50° C. for 2 hours and 30 minutes or more to diffuse Ti into the ZnO piezoelectric thin film 48, thereby imparting conductivity to the piezoelectric thin film in the diffusion region 50 and electrically connecting the second electrode 49 and the extraction electrode 46.
更にこの上に少なくとも圧電薄膜を全て含む大きさでＳ
ｉｎ、膜を付着させてもよい。この５１０１膜は大気の
湿気などに弱いＺｎＯ膜の保護膜として働くだけでなく
周波数温度係数の補償用として働く。またこのような構
成の場合にはＴｉの拡散をＳｉｎ！スバツタ工程と兼ね
ることもできる。同圧を
電薄膜はＺｎＯに限定されるものでな（Ａ ｆＮ 、
ＴａｚＯｗ ＋Ｃｄｓ等の圧電薄膜であれば何を用いて
もよく更に圧電膜の下面もしくは上下面に電極を介在し
て配置される膜の材料は５ｔＯ１に限られるものでなく
化学的に安定な訪電膜やＳｉｎｇにリンを数チ程度ドー
プしたＰＳＧ膜、更にボロンとリンをドープしたＢＰＳ
Ｇやホウケイ酸等のガラス類でもよくそれが単層でなく
異種材料の複合層であってもよい。Furthermore, on top of this, there is formed a film S with a size that includes at least all of the piezoelectric thin film.
In, the membrane may be deposited. This 5101 film not only serves as a protective film for the ZnO film, which is susceptible to atmospheric moisture, but also serves as a compensation for the frequency temperature coefficient. In addition, in the case of such a configuration, Ti diffusion is set to Sin! It can also be used as the subattu process. Thin films with the same voltage are not limited to ZnO (A fN,
Any piezoelectric thin film such as TazOw+Cds can be used. Furthermore, the material of the film arranged with electrodes interposed on the lower surface or upper and lower surfaces of the piezoelectric film is not limited to 5tO1, but any chemically stable electrical conductor can be used. PSG film doped with several tbsp of phosphorus in the film and Sing, BPS further doped with boron and phosphorus
It may be made of glass such as G or borosilicate, and it may not be a single layer but a composite layer of different materials.
更にＺｎＯ圧電薄膜中に拡散される材料はＴｉに限られ
るものでなく拡散定数の大きい金属例えばＣｒ、Ｉｎ、
Ｎｉ、Ｓｎ、Ａｔ、Ｍｇ、Ｌｉ等であれば何を用いても
よい。Furthermore, the material diffused into the ZnO piezoelectric thin film is not limited to Ti, but may also include metals with a large diffusion constant such as Cr, In,
Any material such as Ni, Sn, At, Mg, Li, etc. may be used.
さらに他の実施例として第７図に示すように。Still another embodiment is shown in FIG.
基板凹部を設けるかわりに空隙層５２を設けることによ
って共振部分を基板より離した形の圧電薄膜共振子と半
導体集積回路を組合せた構造とすることもできる。この
空隙層５２はあらかじめ基板上にＺｎＯ膜等の化学的に
容易に溶解できる数百Ａ〜数μｍの薄膜を所定の大きさ
に付着させその上にＳｉｎ、等の膜４２をスパッタリン
グ法等で付着させ、この上に第１の電極４５．配線電極
５１の露出及び圧電薄膜４８．第２の電極４９さらに共
振子側の電極と集積回路側の配線電極との電気的接続は
第６図の実施例と同様の手順で形成し最終的にＺｎＯ圧
電薄膜、引き出し電極をレジストで保護しＳｉｎ、膜の
一部をエツチングしＺｎＯ膜が８ｉ０゜膜で被覆された
部分と被覆されない部分を形成しこれらをＨＣｌ等の溶
液１こつけＺｎＯｈ、を除去することによって形成出来
る。なお最上層にＳｉｎ、膜を付着させてもよい。この
８ｉ０．膜は周波数温度係数の補償用と空隙層形成の際
のＺｎＯ圧電薄膜の保護としても働く。By providing a gap layer 52 instead of providing a substrate recess, it is also possible to obtain a structure in which a piezoelectric thin film resonator with a resonant portion separated from the substrate and a semiconductor integrated circuit are combined. This void layer 52 is made by depositing a chemically easily soluble thin film such as a ZnO film with a thickness of several hundred amps to several μm on a substrate in advance, and then depositing a film 42 of Sin or the like on the substrate by sputtering or the like. A first electrode 45. is deposited thereon. Exposure of wiring electrode 51 and piezoelectric thin film 48. The electrical connection between the second electrode 49 and the electrode on the resonator side and the wiring electrode on the integrated circuit side is formed in the same manner as in the embodiment shown in FIG. 6, and finally the ZnO piezoelectric thin film and the extraction electrode are protected with resist. The ZnO film can be formed by etching a part of the ZnO film to form a part covered with the 8i0° film and a part not covered, and then applying a solution such as HCl to these parts and removing the ZnO film. Note that a film of Sin may be attached to the top layer. This 8i0. The membrane also serves as a compensation for the frequency temperature coefficient and as a protection for the ZnO piezoelectric thin film during the formation of the void layer.
このように共振子の第２の電極と引き出し電極をＺｎＯ
圧電薄膜をはさんで形成しこれらをＺｎＯ圧電薄膜の一
部に導電性をもたせて電気的接続した配線構造とすると
、容易、かつ確実な配線が可能となる。In this way, the second electrode and extraction electrode of the resonator are made of ZnO.
If a wiring structure is formed in which piezoelectric thin films are sandwiched and these are electrically connected by imparting conductivity to a part of the ZnO piezoelectric thin film, easy and reliable wiring becomes possible.
この発明によれば、異物が付着したとしても電気的特性
が変化しないきわめて信頼性の高い圧電薄膜共振子を得
ることができる。According to the present invention, it is possible to obtain an extremely reliable piezoelectric thin film resonator whose electrical characteristics do not change even if foreign matter adheres thereto.
また、モールドしても電気的特性が変化しないため、こ
の発明による圧電薄膜共振子と集積回路とを同一の半導
体基板上に形成してモールドすることができる。これに
より発振回路等の超小形化が図れ、しかも従来の集積回
路と同じ形体の電気部品として提供することができる。Furthermore, since the electrical characteristics do not change even when molded, the piezoelectric thin film resonator and integrated circuit according to the present invention can be formed and molded on the same semiconductor substrate. As a result, the oscillation circuit and the like can be made ultra-small and can be provided as an electrical component having the same shape as a conventional integrated circuit.
第１図はこの発明の一実施例に係る圧電薄膜共振子の断
面図、第２図は第１図の圧電薄膜共振子を得る工程を説
明するための各工程における断面図、第３図はこの発明
の他の実施例に係る圧電薄膜共振子の断面図、第４図は
従来の圧電薄膜共振子の断面図、第５図乃至第７図は配
線パターンの具体例を示す図である。
１・・・基板、２・・・下部保護膜、３・・・上部保護
膜。
４・・・上部空隙層保護膜、５・・・圧電体％ ６・・
・下部電極、７・・・上部電極、８・・・下部空隙層、
９・・・上部空隙層、１０・・・埋込み層。
代理人 弁理士 則 近 憲 佑
同 竹 花 喜久男
第１図
第４図
第２図
第３図FIG. 1 is a cross-sectional view of a piezoelectric thin film resonator according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of each step for explaining the process of obtaining the piezoelectric thin film resonator of FIG. 1, and FIG. FIG. 4 is a sectional view of a piezoelectric thin film resonator according to another embodiment of the present invention, FIG. 4 is a sectional view of a conventional piezoelectric thin film resonator, and FIGS. 5 to 7 are diagrams showing specific examples of wiring patterns. 1... Substrate, 2... Lower protective film, 3... Upper protective film. 4... Upper void layer protective film, 5... Piezoelectric material% 6...
- Lower electrode, 7... Upper electrode, 8... Lower void layer,
9... Upper void layer, 10... Buried layer. Agent Patent Attorney Noriyuki Ken Yudo Takehana KikuoFigure 1Figure 4Figure 2Figure 3
Claims (3)
数の電極が接続された圧電体の、基板と反対側の面に上
部空隙層を設け、この上部空隙層を保護するための上部
空隙層保護膜を設けたことを特徴とする圧電薄膜共振子
。(1) An upper void layer is provided on the surface opposite to the substrate of a piezoelectric body formed on an arbitrary substrate via a lower void layer and connected to a plurality of electrodes, and an upper void layer is provided to protect the upper void layer. A piezoelectric thin film resonator characterized by being provided with an upper void layer protective film.
との間、または圧電体と上部空隙層保護膜との間、また
はその両方に設けたことを特徴とする特許請求の範囲第
１項記載の圧電薄膜共振子。(2) Claims characterized in that a protective film for protecting the piezoelectric body is provided between the substrate and the piezoelectric body, between the piezoelectric body and the upper void layer protective film, or both. The piezoelectric thin film resonator according to item 1.
ことを特徴とする特許請求の範囲第１項記載の圧電薄膜
共振子。(3) The piezoelectric thin film resonator according to claim 1, wherein the lower void layer is a hole or groove drilled in the substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP825687A JPH07114340B2 (en) | 1987-01-19 | 1987-01-19 | Piezoelectric thin film resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP825687A JPH07114340B2 (en) | 1987-01-19 | 1987-01-19 | Piezoelectric thin film resonator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63177605A true JPS63177605A (en) | 1988-07-21 |
| JPH07114340B2 JPH07114340B2 (en) | 1995-12-06 |
Family
ID=11688061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP825687A Expired - Lifetime JPH07114340B2 (en) | 1987-01-19 | 1987-01-19 | Piezoelectric thin film resonator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07114340B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004105237A1 (en) * | 2003-05-26 | 2004-12-02 | Murata Manufacturing Co., Ltd. | Piezoelectric electronic component, and production method therefor, communication equipment |
| JP2007159123A (en) * | 2005-11-30 | 2007-06-21 | Agilent Technol Inc | Film bulk acoustic resonator devices with temperature compensation |
| JP2009022052A (en) * | 2001-01-02 | 2009-01-29 | Avago Technologies Wireless Ip (Singapore) Pte Ltd | Solidly mounted multi-resonator bulk acoustic wave filter with patterned acoustic mirror |
| US7671427B2 (en) | 2003-05-22 | 2010-03-02 | Samsung Electronics Co., Ltd. | Method of manufacturing film bulk acoustic resonator using internal stress of metallic film and resonator manufactured thereby |
| WO2014135379A1 (en) * | 2013-03-06 | 2014-09-12 | Epcos Ag | Microacoustic component and method for the production thereof |
-
1987
- 1987-01-19 JP JP825687A patent/JPH07114340B2/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009022052A (en) * | 2001-01-02 | 2009-01-29 | Avago Technologies Wireless Ip (Singapore) Pte Ltd | Solidly mounted multi-resonator bulk acoustic wave filter with patterned acoustic mirror |
| US7671427B2 (en) | 2003-05-22 | 2010-03-02 | Samsung Electronics Co., Ltd. | Method of manufacturing film bulk acoustic resonator using internal stress of metallic film and resonator manufactured thereby |
| US7939356B2 (en) | 2003-05-22 | 2011-05-10 | Samsung Electronics Co., Ltd. | Method of manufacturing film bulk acoustic resonator using internal stress of metallic film and resonator manufactured thereby |
| WO2004105237A1 (en) * | 2003-05-26 | 2004-12-02 | Murata Manufacturing Co., Ltd. | Piezoelectric electronic component, and production method therefor, communication equipment |
| US7342351B2 (en) | 2003-05-26 | 2008-03-11 | Murata Manufacturing Co., Ltd. | Piezoelectric electronic component, and production method therefor, and communication equipment |
| US8123966B2 (en) | 2003-05-26 | 2012-02-28 | Murata Manufacturing Co., Ltd. | Piezoelectric electronic component, process for producing the same, and communication apparatus |
| JP2007159123A (en) * | 2005-11-30 | 2007-06-21 | Agilent Technol Inc | Film bulk acoustic resonator devices with temperature compensation |
| WO2014135379A1 (en) * | 2013-03-06 | 2014-09-12 | Epcos Ag | Microacoustic component and method for the production thereof |
| US9991873B2 (en) | 2013-03-06 | 2018-06-05 | Snaptrack, Inc. | Microacoustic component and method for the production thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07114340B2 (en) | 1995-12-06 |
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