JPH10190405A - Substrate for surface acoustic wave functional device and method of manufacturing the same - Google Patents
Substrate for surface acoustic wave functional device and method of manufacturing the sameInfo
- Publication number
- JPH10190405A JPH10190405A JP34943996A JP34943996A JPH10190405A JP H10190405 A JPH10190405 A JP H10190405A JP 34943996 A JP34943996 A JP 34943996A JP 34943996 A JP34943996 A JP 34943996A JP H10190405 A JPH10190405 A JP H10190405A
- Authority
- JP
- Japan
- Prior art keywords
- substrate
- acoustic wave
- surface acoustic
- film
- epitaxial
- 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
- 239000000758 substrate Substances 0.000 title claims abstract description 115
- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 90
- 238000004519 manufacturing process Methods 0.000 title claims description 26
- 239000004065 semiconductor Substances 0.000 claims abstract description 27
- 229910021421 monocrystalline silicon Inorganic materials 0.000 claims abstract description 24
- 230000005428 wave function Effects 0.000 claims abstract description 19
- 229910004298 SiO 2 Inorganic materials 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 25
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000003486 chemical etching Methods 0.000 claims description 5
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000007254 oxidation reaction Methods 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 229910021426 porous silicon Inorganic materials 0.000 abstract description 16
- 230000007547 defect Effects 0.000 abstract description 9
- 238000004891 communication Methods 0.000 abstract description 6
- 239000013078 crystal Substances 0.000 abstract description 4
- 230000000694 effects Effects 0.000 abstract description 2
- 238000010030 laminating Methods 0.000 abstract 1
- 239000010408 film Substances 0.000 description 48
- 230000008569 process Effects 0.000 description 12
- 238000005530 etching Methods 0.000 description 9
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 description 4
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 4
- 239000010453 quartz Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 239000004593 Epoxy Substances 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 238000006482 condensation reaction Methods 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 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
- PSHMSSXLYVAENJ-UHFFFAOYSA-N dilithium;[oxido(oxoboranyloxy)boranyl]oxy-oxoboranyloxyborinate Chemical compound [Li+].[Li+].O=BOB([O-])OB([O-])OB=O PSHMSSXLYVAENJ-UHFFFAOYSA-N 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
(57)【要約】
【課題】小型無線通信機器等の小型化ため、弾性表面波
素子及び半導体素子を共に形成する基板及びその基板を
用いた弾性表面波デバイスを得る。
【解決手段】圧電基板５上にＳｉＯ2膜５、単結晶Ｓｉ
エピタキシャル基板層２を貼り合わせ法によって形成し
た弾性表面波機能デバイス用基板を構成する。弾性表面
波機能デバイス用基板の単結晶Ｓｉエピタキシャル成長
膜２に半導体回路素子を形成し、Ｓｉエピタキシャル成
長膜２を除いた圧電基板５の露出面の下に弾性表面波素
子を形成し弾性表面波機能デバイスを構成する。
【効果】多孔質Ｓｉ酸化膜を形成し、貼り合わせ接合を
適用することにより圧電基板上に結晶欠陥の極めて少な
い良質な単結晶Ｓｉエピタキシャル成長膜を形成でき
る。圧電基板と単結晶Ｓｉエピタキシャル成長膜の密着
性が確保され、弾性表面波機能デバイス用基板を用いて
ローノイズアンプ、ミキサ等の半導体回路素子及び弾性
表面波素子を１チップで飛躍的に小型化ができる。
(57) Abstract: A substrate for forming both a surface acoustic wave element and a semiconductor element and a surface acoustic wave device using the substrate are provided for miniaturization of a small wireless communication device or the like. SOLUTION: An SiO 2 film 5 and a single crystal Si are formed on a piezoelectric substrate 5.
A substrate for a surface acoustic wave functional device formed by laminating the epitaxial substrate layer 2 is formed. A semiconductor circuit element is formed on the single crystal Si epitaxial growth film 2 of the substrate for a surface acoustic wave function device, and a surface acoustic wave element is formed below the exposed surface of the piezoelectric substrate 5 excluding the Si epitaxial growth film 2. Is configured. [Effect] By forming a porous Si oxide film and applying bonding, it is possible to form a high quality single crystal Si epitaxial growth film having very few crystal defects on a piezoelectric substrate. Adhesion between the piezoelectric substrate and the single-crystal Si epitaxial growth film is ensured, and a semiconductor circuit element such as a low-noise amplifier and a mixer and a surface acoustic wave element can be drastically reduced in one chip using a surface acoustic wave function device substrate. .
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、弾性表面波機能デ
バイス、それに使用する基板及びその基板の製造方法、
更に詳しくいえば、フィルタ、共振器等の弾性表面波素
子と増幅器等の半導体回路素子を含む機能デバイスを単
一の基板上に形成したデバイス（以下、弾性表面波機能
デバイスと略称）、その基板の構成及び製造方法に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device, a substrate used for the device, and a method of manufacturing the substrate.
More specifically, a device in which a functional device including a surface acoustic wave element such as a filter and a resonator and a semiconductor circuit element such as an amplifier is formed on a single substrate (hereinafter, abbreviated as a surface acoustic wave functional device), And a manufacturing method.
【０００２】[0002]
【従来の技術】携帯電話器等の携帯無線通信端末機器の
構成においては、機器の小型化が強く要求される。ＬＳ
Ｉ、弾性表面波素子の使用により、機器の小型化がかな
り進んだが、さらに機器を小型化する必要がある。従
来、弾性表面波素子は水晶基板、リチウムタンタレート
基板、リチウムナイオベート基板等の圧電基板上に金属
薄膜の櫛形交差電極指を形成して構成され、実際には単
体部品として気密封止されて使用されいる。例えば、電
子情報通信学会論文誌 ジェイ７６-エイ巻 ２号２３
８頁 １９９３年２月（電子情報通信学会論文誌 Vol.
J75-A No.2 p2381993/2)に示されているように、弾性表
面波フロントエンドモジュールはアルミナ基板、ガラス
エポキシ基板等の誘電体基板上に銅厚膜回路を印刷し、
ローノイズアンプ等の回路素子と共に弾性表面波フィル
タ、ミキサ等の弾性表面波素子の単体部品を実装して構
成している。2. Description of the Related Art In the construction of portable radio communication terminal devices such as portable telephones, miniaturization of the devices is strongly required. LS
I. The use of surface acoustic wave devices has considerably reduced the size of equipment, but it is necessary to further reduce the size of equipment. Conventionally, a surface acoustic wave device is formed by forming comb-shaped fingers of a metal thin film on a piezoelectric substrate such as a quartz substrate, a lithium tantalate substrate, or a lithium niobate substrate, and is actually hermetically sealed as a single component. Used. For example, IEICE Transactions, Jay 76-A Vol. 2, No. 23
8 February 1993 (Transactions of the Institute of Electronics, Information and Communication Engineers, Vol.
As shown in J75-A No.2 p2381993 / 2), the surface acoustic wave front-end module prints a copper thick film circuit on a dielectric substrate such as an alumina substrate, a glass epoxy substrate, etc.
A single component of a surface acoustic wave element such as a surface acoustic wave filter and a mixer is mounted together with a circuit element such as a low noise amplifier.
【０００３】[0003]
【発明が解決しようとする課題】上述のように小型無線
通信機器等は一層の小型化、軽量化の要求が強く、現在
のものより飛躍的に小型化した機器の開発が必要となっ
ているが、従来の通信機器等の構成は、弾性表面波素子
の部品とアンプ、ミキサ等のデバイスの主要部品はそれ
ぞれ独立にパッケージされ、それ等を接続線をプリント
印刷した誘電体基板上に個別に実装して構成しているた
め、一定のスペースを必要とし、機器の小型化には限界
があった。また実装の工程を必要とし、製造コスト低減
の障害となっている。As described above, there is a strong demand for further miniaturization and weight reduction of small wireless communication devices and the like, and it is necessary to develop devices that are significantly smaller than the current ones. However, in the conventional configuration of communication equipment, the components of the surface acoustic wave element and the main components of the device such as the amplifier and mixer are packaged independently, and they are individually mounted on a dielectric substrate on which connection lines are printed. Since it is mounted and configured, it requires a certain space, and there is a limit to miniaturization of the device. In addition, a mounting process is required, which is an obstacle to reducing the manufacturing cost.
【０００４】従って、本発明は、上記の問題を解決し、
小型化が最大の特徴である弾性表面波素子の長所を十分
に活かし、従来誘電体基板上に実装されている各種部品
を含めて飛躍的な小型化ができる弾性表面波機能デバイ
ス及びそれに使用する基板の製造方法を実現することを
目的とする。Accordingly, the present invention solves the above problems,
A surface acoustic wave device capable of dramatically reducing its size, including various components conventionally mounted on a dielectric substrate, making full use of the advantages of a surface acoustic wave device, whose main feature is miniaturization, and its use. It is an object to realize a method for manufacturing a substrate.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するため
に、本発明は弾性表面波を伝搬する圧電基板上の少なく
とも一部にエピタキシャルＳｉ基板層を形成した弾性表
面波機能デバイス用基板を構成し、上記弾性表面波機能
板のエピタキシャルＳｉ基板層に半導体回路素子を、圧
電基板に弾性表面波を直接形成し弾性表面波機能デバイ
スを作成する。To achieve the above object, the present invention provides a surface acoustic wave functional device substrate having an epitaxial Si substrate layer formed on at least a part of a piezoelectric substrate that propagates a surface acoustic wave. Then, a semiconductor circuit element is formed directly on the epitaxial Si substrate layer of the surface acoustic wave functional plate, and a surface acoustic wave is directly formed on the piezoelectric substrate, thereby producing a surface acoustic wave functional device.
【０００６】そのために、本発明の弾性表面波機能デバ
イスの基板の製造方法では、次の工程で基板を製造す
る。 （１）圧電基板上にＳｉ０2層を形成する。 （２）一面にエピタキシャルＳｉ層をもつＳｉ基板を形
成する。 （３）上記Ｓｉ０2層と上記エピタキシャルＳｉ層が接
着するように上記圧電基板と上記Ｓｉ層とを貼り合わせ
る。 （４）貼り合わされたＳｉ基板層を上記エピタキシャル
Ｓｉ層が露出するように削除する。Therefore, in the method of manufacturing a substrate for a surface acoustic wave function device according to the present invention, the substrate is manufactured in the following steps. (1) forming a Si0 2 layer on a piezoelectric substrate. (2) An Si substrate having an epitaxial Si layer on one surface is formed. (3) The Si0 2 layer and the epitaxial Si layer is bonded to the aforementioned piezoelectric substrate and the Si layer to adhere. (4) The bonded Si substrate layer is deleted so that the epitaxial Si layer is exposed.
【０００７】また、本発明の弾性表面波機能デバイスは
上記基板の製造方法で得られた基板のエピタキシャルＳ
ｉ層に従来と同じ半導体プロセスで回路素子及び弾性表
面波素子を形成する。弾性表面波素子は、上記基板に弾
性表面波素子を形成する領域に圧電基板が露出するよう
に上記エピタキシャルＳｉ層を除き、露出した圧電基板
上に電極指をパターンニングすることにより形成され
る。Further, the surface acoustic wave function device of the present invention is characterized in that an epitaxial S
A circuit element and a surface acoustic wave element are formed on the i-layer by the same semiconductor process as before. The surface acoustic wave device is formed by patterning electrode fingers on the exposed piezoelectric substrate except for the epitaxial Si layer so that the piezoelectric substrate is exposed in a region where the surface acoustic wave device is formed on the substrate.
【０００８】上記弾性表面波機能デバイス用基板の製造
方法において、単結晶Ｓｉエピタキシャル成長膜の下に
形成された多孔質Ｓｉ酸化膜により、貼り合わせ接合を
適用しても良質な単結晶Ｓｉエピタキシャル層が得られ
る。また、結晶欠陥も少なく回路素子の構成に最適の基
板ができる。In the method of manufacturing a substrate for a surface acoustic wave function device, the porous Si oxide film formed under the single-crystal Si epitaxial growth film can form a single-crystal Si epitaxial layer of good quality even when bonding is applied. can get. In addition, a substrate having few crystal defects and optimal for the configuration of a circuit element can be obtained.
【０００９】本発明の弾性表面波機能デバイスは、単一
の基板において通常の半導体プロセス及び弾性表面波素
子の製造と同様の工程を行うことができ、従来のアルミ
ナ、ガラスエポキシ等の基板上でパッケージされた各種
部品を実装するための空間を除くことができ、弾性表面
波機能デバイス機器の小型化が実現される。さらに半導
体プロセス及び弾性表面波素子のパッケージ化が不要と
なり、製造工程を短縮できる。The surface acoustic wave function device of the present invention can perform the same process as a normal semiconductor process and the manufacture of a surface acoustic wave element on a single substrate, and can be performed on a conventional substrate of alumina, glass epoxy or the like. The space for mounting various packaged components can be eliminated, and the size of the surface acoustic wave function device can be reduced. Further, the semiconductor process and the packaging of the surface acoustic wave element become unnecessary, and the manufacturing process can be shortened.
【００１０】[0010]
【発明の実施の形態】本発明の具体的な実施の形態を説
明する。図１は、本発明による弾性表面波機能デバイス
の製造工程のの途中の一実施形態を示す斜視図である。
弾性表面波を発生させる圧電基板は、リチウムタンタレ
ート（ＬｉＴａＯ3）、リチウムナイオベート（ＬｉＮ
ｂＯ3）、リチウムテトラボレート（Ｌｉ2Ｂ4Ｏ7）、水
晶（Ｑｕａｒｔｚ）等を基板１としている。基板１上に
ローノイズアンプ、ミキサ等の半導体回路素子及び伝送
線（配線）を形成するためのＳｉ基板層としてエピタキ
シャル成長Ｓｉ膜２を形成している。図のように形成す
ることにより１枚の基板において、圧電基板１が露出し
た部分に弾性表面波素子が、エピタキシャル成長Ｓｉ膜
２上に半導体回路素子とが形成され、弾性表面波素子の
製造工程のなかで、弾性表面波素子と半導体回路素子の
接続も同時に行われる。DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described. FIG. 1 is a perspective view showing an embodiment in the middle of the manufacturing process of the surface acoustic wave device according to the present invention.
The piezoelectric substrates that generate surface acoustic waves include lithium tantalate (LiTaO 3 ) and lithium niobate (LiN
The substrate 1 is made of bO 3 ), lithium tetraborate (Li 2 B 4 O 7 ), quartz (Quartz), or the like. An epitaxially grown Si film 2 is formed on a substrate 1 as a Si substrate layer for forming a semiconductor circuit element such as a low noise amplifier and a mixer and a transmission line (wiring). By forming as shown in the figure, a surface acoustic wave element is formed on a portion of the substrate where the piezoelectric substrate 1 is exposed, and a semiconductor circuit element is formed on the epitaxially grown Si film 2. Among them, the connection between the surface acoustic wave element and the semiconductor circuit element is performed simultaneously.
【００１１】図２は、本発明による弾性表面波機能デバ
イスに使用する基板の製造方法の一実施形態を説明する
ための製造工程図である。なお、図面は説明の簡明のた
め、基板の一部についてのみ示している。FIG. 2 is a manufacturing process diagram for explaining an embodiment of a method of manufacturing a substrate used in a surface acoustic wave device according to the present invention. The drawings show only a part of the substrate for simplicity of explanation.
【００１２】（ａ）、Ｓｉ基板３上に多孔質Ｓｉ酸化膜
４、その上に単結晶Ｓｉエピタキシャル成長膜２を形成
する。Ｓｉエピタキシャル成長膜２の形成過程は、初め
にＳｉ基板３の表面上に膜厚１０μｍ程度の多孔質Ｓｉ
酸化膜４を陽極酸化により形成し、次に、Ｓｉ酸化膜４
の表面に単結晶Ｓｉ膜２をエピタキシャル成長させる。
ここで、単結晶Ｓｉエピタキシャル成長膜２の欠陥を低
減させるために、通常のホモエピタキシャル成長時にも
行われている表面の自然酸化膜除去のためのＨ2熱処理
を１０００℃以上の温度で行うことにより、多孔質Ｓｉ
酸化膜４表面の孔が消失し表面が平坦になる。孔が空い
たままの多孔質Ｓｉ酸化膜４の表面にエピタキシャル成
長させると莫大な量の欠陥が発生するが、Ｈ2熱処理に
より孔が消失された多孔質Ｓｉ酸化膜４表面では欠陥を
激減することができる。さらに、欠陥を少なくするには
エピタキシャル成長装置に入れる直前のＨＦ処理時間を
３分以上行うことが有効である。(A) A porous Si oxide film 4 is formed on a Si substrate 3, and a single crystal Si epitaxial growth film 2 is formed thereon. In the process of forming the Si epitaxial growth film 2, first, a porous Si film having a thickness of about 10 μm is formed on the surface of the Si substrate 3.
An oxide film 4 is formed by anodic oxidation.
A single crystal Si film 2 is epitaxially grown on the surface of the substrate.
Here, in order to reduce defects in the single crystal Si epitaxial growth film 2, H 2 heat treatment for removing a natural oxide film on the surface, which is also performed during normal homoepitaxial growth, is performed at a temperature of 1000 ° C. or more. Porous Si
The holes on the surface of the oxide film 4 disappear, and the surface becomes flat. When epitaxial growth is performed on the surface of the porous Si oxide film 4 in which holes are left open, an enormous amount of defects are generated, but the defects are drastically reduced on the surface of the porous Si oxide film 4 in which the holes have been eliminated by the H 2 heat treatment. Can be. Further, in order to reduce the number of defects, it is effective to carry out the HF treatment time immediately before entering the epitaxial growth apparatus for 3 minutes or more.
【００１３】（ｂ）、（ａ）の単結晶Ｓｉエピタキシャ
ル成長膜２の形成とは別に、圧電基板１上に膜厚２００
Å程度のＳｉＯ2膜５をスパッタ法もしくはＣＶＤ法等
の通常の方法により形成する。ここで、圧電基板１上に
ＳｉＯ2膜５を形成することにより、基板を貼り合わ
せ、加熱による脱水縮合反応で結合させる際に問題とな
るボイド欠陥の発生を抑えることができる。これは、Ｓ
ｉＯ2膜が加熱により発生した水もしくはＯＨ基を吸収
することによるものである。In addition to the formation of the single-crystal Si epitaxial growth film 2 shown in FIGS.
A SiO 2 film 5 of about Å is formed by a normal method such as a sputtering method or a CVD method. Here, by forming the SiO 2 film 5 on the piezoelectric substrate 1, it is possible to suppress the generation of void defects which are a problem when the substrates are bonded to each other and bonded by a dehydration condensation reaction by heating. This is S
This is because the iO 2 film absorbs water or OH groups generated by heating.
【００１４】（ｃ）、（ａ）のＳｉ基板３の単結晶Ｓｉ
エピタキシャル成長膜２側と（ｂ）の圧電基板１のＳｉ
Ｏ2膜５側を貼り合わせて、加熱し、脱水縮合反応によ
り結合させる。この時の加熱温度を４００℃以下と抑え
ることで、熱膨張係数の差による欠陥の発生を抑え、か
つ基板の反りを抑える。 （ｄ）、次に、Ｓｉ基板３側の裏面から多孔質Ｓｉ酸化
膜４が全面露出するまでＳｉ基板３を研削する。(C) Single crystal Si of Si substrate 3 in (a)
Si on the epitaxial growth film 2 side and the piezoelectric substrate 1 of (b)
The O 2 film 5 side is bonded, heated, and bonded by a dehydration condensation reaction. By suppressing the heating temperature at this time to 400 ° C. or less, the occurrence of defects due to the difference in thermal expansion coefficient is suppressed, and the warpage of the substrate is suppressed. (D) Next, the Si substrate 3 is ground until the entire surface of the porous Si oxide film 4 is exposed from the back surface on the Si substrate 3 side.
【００１５】（ｅ）、さらに、選択性化学エッチングで
多孔質Ｓｉ酸化膜４を溶解させ、単結晶Ｓｉエピタキシ
ャル成長膜２を露出する。ここで重要なことは、Ｓｉ基
板３と単結晶Ｓｉエピタキシャル成長膜２間に多孔質Ｓ
ｉ酸化膜４を用いたことである。このことにより、単結
晶Ｓｉエピタキシャル成長膜２と多孔質Ｓｉ酸化膜４の
選択性化学エッチングにおいてエッチング選択比が大き
く取れる実用的なエッチング液が使える。ここで用いる
エッチング液はＨＦに弱酸化剤のＨ2Ｏ2を添加したもの
を用いる。この時、多孔質Ｓｉ酸化膜４のエッチング速
度は２μｍ／分以上と速く、多孔質Ｓｉ酸化膜４／単結
晶Ｓｉエピタキシャル成長膜２のエッチング選択比は１
０5程度と非常に大きい値が実現できる。また、選択性
化学エッチングはエッチング液が多孔質Ｓｉ酸化膜４の
孔内部に毛細管現象により侵入し、孔径を拡げることに
よりＳｉ柱が細り、内部からの崩壊が始まると考えられ
る。これによりエッチングが進行し、多孔質Ｓｉは消失
し単結晶Ｓｉエピタキシャル成長膜２が得られる。多孔
質Ｓｉは内部から崩壊するため膜厚変動の原因となる基
板の表面パーティクルやエッチング中に浮遊、沈着する
パーティクルに影響されない。(E) Further, the porous Si oxide film 4 is dissolved by selective chemical etching to expose the single crystal Si epitaxial growth film 2. What is important here is that a porous S film is formed between the Si substrate 3 and the single crystal Si epitaxial growth film 2.
That is, the i-oxide film 4 is used. As a result, a practical etchant that can obtain a large etching selectivity in the selective chemical etching of the single crystal Si epitaxial growth film 2 and the porous Si oxide film 4 can be used. The etchant used here is a mixture of HF and a weak oxidant, H 2 O 2 . At this time, the etching rate of the porous Si oxide film 4 is as fast as 2 μm / min or more, and the etching selectivity of the porous Si oxide film 4 / single crystal Si epitaxial growth film 2 is 1
A very large value of about 0 5 can be realized. In the selective chemical etching, it is considered that the etchant penetrates into the pores of the porous Si oxide film 4 by capillary action, and the Si pillars become thinner by expanding the pore diameter, and collapse from inside begins. As a result, the etching proceeds, the porous Si disappears, and a single crystal Si epitaxial growth film 2 is obtained. Since the porous Si collapses from the inside, it is not affected by particles on the surface of the substrate that cause fluctuations in the film thickness, or particles that float or deposit during etching.
【００１６】よって、膜厚数百ｎｍの単結晶Ｓｉエピタ
キシャル成長膜２に対して膜厚変動を数ｎｍに抑えるこ
とが可能であり、この方法を適用することにより０．５
〜０．１μｍという薄膜の単結晶Ｓｉエピタキシャル成
長膜２も膜厚変動が問題とならずに形成される。Therefore, it is possible to suppress the variation in film thickness to several nm for the single crystal Si epitaxial growth film 2 having a thickness of several hundred nm.
The single-crystal Si epitaxial growth film 2 having a thin film thickness of about 0.1 μm is also formed without causing a problem in thickness variation.
【００１７】図３は、本発明による弾性表面波機能デバ
イス用基板に半導体回路素子を形成する工程の一部を示
す断面図である。図２に説明した方法で得られた基板を
通常のホトレジスト工程によりローノイズアンプ、ミキ
サ等の回路素子を形成するための単結晶Ｓｉエピタキシ
ャル成長膜２の部分のみをレジストパターン６でコート
し、その後フッ酸等のエッチング液を使用した選択性化
学エッチングもしくはＳＦ6、ＣＦ4等のエッチングガス
を使用した反応性イオンエッチング等の通常のエッチン
グ工程によりＳｉ基板層を除去する。これにより、弾性
表面波機能デバイスを構成する回路素子を形成する領域
を任意に選定し、圧電基板１上にＳｉＯ2膜５を介して
単結晶Ｓｉエピタキシャル成長膜２を形成することがで
き、図１に示した弾性表面波機能デバイスを得る。FIG. 3 is a sectional view showing a part of a step of forming a semiconductor circuit element on a substrate for a surface acoustic wave function device according to the present invention. The substrate obtained by the method described with reference to FIG. 2 is coated with a resist pattern 6 only on a portion of the single crystal Si epitaxial growth film 2 for forming circuit elements such as a low noise amplifier and a mixer by a normal photoresist process, and then hydrofluoric acid. The Si substrate layer is removed by a normal etching process such as selective chemical etching using an etching solution such as an etching gas or reactive ion etching using an etching gas such as SF 6 or CF 4 . As a result, it is possible to arbitrarily select a region where a circuit element constituting the surface acoustic wave function device is to be formed, and to form the single crystal Si epitaxial growth film 2 on the piezoelectric substrate 1 via the SiO 2 film 5. Are obtained.
【００１８】図４は、本発明による弾性表面波機能デバ
イスの一実施形態を示す斜視図である。本実施例の弾性
表面波機能デバイスは、スペクトル拡散通信用受信装置
を構成したものである。アンテナ１２からの受信信号は
弾性表面波フィルタ９−１を回してローノイズアンプ７
−１に加えられる。アンプ７−１の出力は第２の弾性表
面波フィルタ９−２を介してミキサ８の一入力となる。
アンプ７−２と弾性表面波レゾネータ１０は発信器を構
成し、発信器の一部は弾性表面波フィルタ９−３を介し
ててミキサ８の他の入力となる。入力端子１５から加え
られるＰＮ信号は弾性表面波共振器１３に加えられる。
共振器１３の信号は弾性表面波コンボルバ１１に加えら
れ復号され、出力端子１４より出力される。FIG. 4 is a perspective view showing an embodiment of a surface acoustic wave function device according to the present invention. The surface acoustic wave function device of the present embodiment constitutes a receiver for spread spectrum communication. The received signal from the antenna 12 is turned by the surface acoustic wave filter 9-1 to the low noise amplifier 7.
It is added to -1. The output of the amplifier 7-1 becomes one input of the mixer 8 via the second surface acoustic wave filter 9-2.
The amplifier 7-2 and the surface acoustic wave resonator 10 constitute a transmitter, and a part of the transmitter becomes another input of the mixer 8 via the surface acoustic wave filter 9-3. The PN signal applied from the input terminal 15 is applied to the surface acoustic wave resonator 13.
The signal of the resonator 13 is applied to the surface acoustic wave convolver 11, decoded, and output from the output terminal 14.
【００１９】上記弾性表面波機能デバイスの作成は次の
ように行われる。図２、図３によって説明した方法によ
って得られた弾性表面波機能デバイス用基板の単結晶Ｓ
ｉエピタキシャル成長膜２上にアンプ７−１、７−２、
ミキサ８等の半導体回路素子（Ｓｉデバイス）を従来知
られている半導体プロセスで構成する。この半導体プロ
セスにおいては、圧電基板１が露出している部分を常に
レジスト膜でコーティングして製造プロセスを進め、半
導体回路素子形成時の製造プロセスによって圧電基板１
に悪影響を与えないようにする。The production of the above surface acoustic wave function device is performed as follows. Single crystal S of surface acoustic wave functional device substrate obtained by the method described with reference to FIGS.
The amplifiers 7-1 and 7-2 on the i-epitaxial growth film 2
A semiconductor circuit element (Si device) such as the mixer 8 is formed by a conventionally known semiconductor process. In this semiconductor process, the portion where the piezoelectric substrate 1 is exposed is always coated with a resist film to proceed with the manufacturing process.
Should not be adversely affected.
【００２０】半導体回路素子を形成した後に弾性表面波
フィルタ９−１、９−２、９−３、弾性表面波レゾネー
タ１０、弾性表面波コンボルバ１１、弾性表面波共振器
１３等の弾性表面波素子を圧電基板１上に形成する。こ
の場合半導体回路素子と弾性表面波素子の接続配線も同
時に行う。ここでも先工程と同様に半導体素子を形成し
た部分を常にレジストパターンでコーティングして保護
する。このように半導体素子部、弾性表面波素子部をそ
れぞれレジストパターンにより保護し製造プロセスを進
めることにより、通常のデバイス作製プロセスと同様の
方法で弾性表面波機能デバイスを作製することができ
る。ここで、上記実施例では半導体回路素子を先に形成
しているが、弾性表面波素子を先に形成してもよいこと
は言うまでもない。After the semiconductor circuit elements are formed, surface acoustic wave devices such as surface acoustic wave filters 9-1, 9-2, 9-3, surface acoustic wave resonator 10, surface acoustic wave convolver 11, and surface acoustic wave resonator 13. Is formed on the piezoelectric substrate 1. In this case, connection wiring between the semiconductor circuit element and the surface acoustic wave element is performed at the same time. Here, as in the previous step, the portion where the semiconductor element is formed is always protected by coating with a resist pattern. As described above, the semiconductor element portion and the surface acoustic wave element portion are each protected by the resist pattern and the manufacturing process is advanced, so that a surface acoustic wave functional device can be manufactured by the same method as a normal device manufacturing process. Here, in the above embodiment, the semiconductor circuit element is formed first, but it goes without saying that the surface acoustic wave element may be formed first.
【００２１】弾性表面波を発生させる圧電基板としてリ
チウムタンタレート、リチウムナイオベート基板を用い
ると、電気機械結合係数が大きいためＲＦフィルタや共
振器以外にコンボルバ、マッチトフィルタ等も通常のＳ
ＡＷプロセスで実現できる。When a lithium tantalate or lithium niobate substrate is used as a piezoelectric substrate for generating a surface acoustic wave, the electromechanical coupling coefficient is large.
It can be realized by the AW process.
【００２２】[0022]
【発明の効果】本発明によれば水晶基板、リチウムタン
タレート基板、リチウムナイオベート基板等の圧電基板
上に結晶欠陥の極めて少ない単結晶Ｓｉエピタキシャル
成長膜を形成できることから、単結晶Ｓｉエピタキシャ
ル成長膜上にローノイズアンプ、ミキサ等のデバイス
が、また圧電基板上には弾性表面波フィルタ、弾性表面
波レゾネータ等の弾性表面波デバイスが良好な性能を持
って形成でき、ＲＦ回路等が１チップで実現可能となっ
た。従来はアルミナ、ガラスエポキシ基板上に個別部品
を実装して実現していたＲＦ回路が１チップのデバイス
として作成出来る。素子の小型化、ひいては端末の小型
化に充分な効果を得ることが出来る。According to the present invention, a single-crystal Si epitaxial growth film having extremely few crystal defects can be formed on a piezoelectric substrate such as a quartz substrate, a lithium tantalate substrate, or a lithium niobate substrate. Devices such as low-noise amplifiers and mixers, and surface acoustic wave devices such as surface acoustic wave filters and surface acoustic wave resonators on piezoelectric substrates can be formed with good performance, and RF circuits can be realized with one chip. became. An RF circuit conventionally implemented by mounting individual components on an alumina or glass epoxy substrate can be created as a one-chip device. A sufficient effect can be obtained for miniaturization of the element and, consequently, miniaturization of the terminal.
【００２３】さらに組み合わせる基板を選択することに
より、多種多様な機能デバイスの１チップ化の可能性が
あり、将来の携帯情報端末等においては小型化の面で必
須のデバイスが実現できる。Further, by selecting a board to be combined, there is a possibility that a variety of functional devices can be integrated into one chip, and in a future portable information terminal or the like, an indispensable device in terms of miniaturization can be realized.
【図１】本発明による弾性表面波機能デバイスの製造の
途中の一実施形態を示す斜視図FIG. 1 is a perspective view showing an embodiment of a surface acoustic wave functional device according to the present invention during its production.
【図２】本発明による弾性表面波機能デバイスに使用す
る基板の製造方法の一実施形態を説明するための製造工
程図FIG. 2 is a manufacturing process diagram for explaining an embodiment of a method of manufacturing a substrate used for a surface acoustic wave device according to the present invention.
【図３】本発明による弾性表面波機能デバイス用基板に
半導体回路素子をを形成する工程の一部を示す断面図FIG. 3 is a cross-sectional view showing a part of a process of forming a semiconductor circuit element on a surface acoustic wave function device substrate according to the present invention.
【図４】本発明による弾性表面波機能デバイスの一実施
形態の斜視図。FIG. 4 is a perspective view of one embodiment of a surface acoustic wave function device according to the present invention.
１…圧電基板、２…単結晶Ｓｉエピタキシャル成長膜、
３…Ｓｉ基板、４…多孔質Ｓｉ酸化膜、５…ＳｉＯ
2膜、６…レジストパターン、７…ローノイズアンプ、
８…ミキサ、９…弾性表面波フィルタ、１０…弾性表面
波レゾネータ、１１…弾性表面波コンボルバ、１２…ア
ンテナ、１３…弾性表面波共振器、１４…出力端子、１
５…入力端子。1. Piezoelectric substrate, 2. Single crystal Si epitaxial growth film,
3 ... Si substrate, 4 ... porous Si oxide film, 5 ... SiO
2 film, 6: resist pattern, 7: low noise amplifier,
8 mixer, 9 surface acoustic wave filter, 10 surface acoustic wave resonator, 11 surface acoustic wave convolver, 12 antenna, 13 surface acoustic wave resonator, 14 output terminal, 1
5. Input terminal.
Claims (10)
とも一部にエピタキシャルＳｉ基板層を形成したことを
特徴とする弾性表面波機能デバイス用基板。1. A substrate for a surface acoustic wave functional device, wherein an epitaxial Si substrate layer is formed on at least a part of a piezoelectric substrate that propagates a surface acoustic wave.
とも一部にＳｉＯ2層、エピタキシャルＳｉ層が順に形
成されたことを特徴とする弾性表面波機能デバイス用基
板。2. A substrate for a surface acoustic wave functional device, wherein a SiO 2 layer and an epitaxial Si layer are formed in this order on at least a part of a piezoelectric substrate that propagates a surface acoustic wave.
シャルＳｉ基板層をもつ基板を貼り合わせて接合面を形
成した基板を作ることを特徴とする弾性表面波機能デバ
イス用基板の製造方法。3. A method of manufacturing a substrate for a surface acoustic wave function device, comprising: bonding a piezoelectric substrate that propagates a surface acoustic wave to a substrate having an epitaxial Si substrate layer to form a substrate having a bonding surface.
Ｏ2膜を形成する第１工程と、Ｓｉ基板の表面を酸化さ
せＳｉＯ2膜を形成する第２工程と、上記第２工程で形
成されたＳｉＯ2膜上に単結晶Ｓｉをエピタキシャル成
長させる第３工程と、上記第１工程で得られた圧電基板
のＳｉＯ2膜と上記第３工程で得られるＳｉ基板のＳｉ
エピタキシャル層を貼り合わせる第４工程と、第４工程
でえられた貼り合わせた基板のＳｉ基板を酸化膜が全面
に露出するまでＳｉ基板を研削する第５工程をもつこと
を特徴とする弾性表面波機能デバイス用基板の製造方
法。4. The method according to claim 1, wherein the surface of the piezoelectric substrate that propagates the surface acoustic wave is covered with Si.
A first step of forming an O 2 film, a second step of oxidizing the surface of the Si substrate to form a SiO 2 film, and a third step of epitaxially growing single-crystal Si on the SiO 2 film formed in the second step. And the SiO 2 film of the piezoelectric substrate obtained in the first step and the Si film of the Si substrate obtained in the third step.
An elastic surface, comprising: a fourth step of bonding an epitaxial layer; and a fifth step of grinding the Si substrate of the bonded substrate obtained in the fourth step until an oxide film is entirely exposed. A method for manufacturing a substrate for a wave function device.
膜を選択性化学エッチングにより溶解させる工程をもつ
ことを特徴とする弾性表面波機能デバイス用基板の製造
方法。5. A method for manufacturing a substrate for a surface acoustic wave function device, comprising a step of dissolving an oxide film exposed after the fifth step according to the fourth step by selective chemical etching.
極酸化で行い、酸化膜を多孔質化させることを特徴とす
る請求項４又は５記載の弾性表面波機能デバイス用基板
の製造方法。6. The production of a substrate for a surface acoustic wave functional device according to claim 4, wherein the oxidation of the surface of the Si substrate in the second step is performed by anodic oxidation to make the oxide film porous. Method.
キシャル成長工程において、前処理工程としてＨＦ処理
を３分以上おこない、さらにＨ2熱処理を１０００℃以
上の温度で行うことを特徴とする請求項４又は５記載の
弾性表面波機能デバイス用基板の製造方法。7. The method according to claim 3, wherein in the third step of epitaxially growing the single crystal Si substrate layer, HF treatment is performed as a pretreatment step for 3 minutes or more, and H 2 heat treatment is performed at a temperature of 1000 ° C. or more. Item 6. The method for manufacturing a substrate for a surface acoustic wave function device according to item 4 or 5.
を４００℃以下の温度で加熱することを特徴とする請求
項４又は５記載の弾性表面波機能デバイス用基板の製造
方法。8. The method for manufacturing a surface acoustic wave functional device substrate according to claim 4, wherein, after the fourth step, the bonded substrate is heated at a temperature of 400 ° C. or less.
弾性表面波機能デバイス用基板の製造方法で製造された
弾性表面波機能デバイス用基板のＳｉエピタキシャル成
長層を半導体回路素子を形成する領域を残し上記圧電基
板が露出するように除去する工程と、上記半導体回路素
子を形成する領域に半導体回路素子を形成する工程又は
上記圧電基板が露出した領域に弾性表面波素子を形成す
る工程と、その後上記圧電基板が露出した領域に弾性表
面波素子を形成する工程又は上記半導体回路素子を形成
する領域に半導体回路素子を形成する工程をもつことを
特徴とする弾性表面波機能デバイスの製造方法。9. A semiconductor circuit element is formed from a Si epitaxial growth layer of a surface acoustic wave function device substrate manufactured by the method for manufacturing a surface acoustic wave device device according to any one of claims 3 to 8. Removing the piezoelectric substrate so that the piezoelectric substrate is exposed, leaving a region; forming a semiconductor circuit element in a region where the semiconductor circuit element is formed; or forming a surface acoustic wave element in a region where the piezoelectric substrate is exposed. Forming a surface acoustic wave element in a region where the piezoelectric substrate is exposed or a step of forming a semiconductor circuit element in a region where the semiconductor circuit element is formed. .
くとも一部にエピタキシャルＳｉ基板層が形成され、上
記エピタキシャルＳｉ基板層に半導体回路素子が形成さ
れ、エピタキシャルＳｉ基板層がない圧電基板上に弾性
表面素子が形成されたことを特徴とする弾性表面波機能
デバイス。10. A piezoelectric substrate on which an epitaxial Si substrate layer is formed on at least a part of a piezoelectric substrate that propagates a surface acoustic wave, a semiconductor circuit element is formed on the epitaxial Si substrate layer, and no epitaxial Si substrate layer is provided. A surface acoustic wave functional device having a surface acoustic wave element formed thereon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34943996A JP3335543B2 (en) | 1996-12-27 | 1996-12-27 | Surface acoustic wave functional device and method of manufacturing substrate for surface acoustic wave functional device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34943996A JP3335543B2 (en) | 1996-12-27 | 1996-12-27 | Surface acoustic wave functional device and method of manufacturing substrate for surface acoustic wave functional device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10190405A true JPH10190405A (en) | 1998-07-21 |
| JP3335543B2 JP3335543B2 (en) | 2002-10-21 |
Family
ID=18403763
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34943996A Expired - Fee Related JP3335543B2 (en) | 1996-12-27 | 1996-12-27 | Surface acoustic wave functional device and method of manufacturing substrate for surface acoustic wave functional device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3335543B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6467139B1 (en) | 1998-08-03 | 2002-10-22 | Nec Corporation | Mounting structure and mounting method for surface acoustic wave element |
-
1996
- 1996-12-27 JP JP34943996A patent/JP3335543B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6467139B1 (en) | 1998-08-03 | 2002-10-22 | Nec Corporation | Mounting structure and mounting method for surface acoustic wave element |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3335543B2 (en) | 2002-10-21 |
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