JP3729192B2 - Semiconductor sensor and method for manufacturing the same - Google Patents

Semiconductor sensor and method for manufacturing the same Download PDF

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JP3729192B2
JP3729192B2 JP2003314796A JP2003314796A JP3729192B2 JP 3729192 B2 JP3729192 B2 JP 3729192B2 JP 2003314796 A JP2003314796 A JP 2003314796A JP 2003314796 A JP2003314796 A JP 2003314796A JP 3729192 B2 JP3729192 B2 JP 3729192B2
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substrate
electrode
insulating layer
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movable
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雅人 橋本
勝 長尾
英美 千田
和身 千田
敬子 根木
倫久 岡山
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Toyota Motor Corp
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Description

本発明は、基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部とを備えた加速度や角速度等を検出する半導体センサ、及びその製造方法に関する。   The present invention relates to a semiconductor sensor that detects acceleration, angular velocity, and the like, including a movable part supported on a substrate through an insulating layer so as to vibrate, and a detection part that detects displacement of the movable part, and a method for manufacturing the same. .

この種の半導体センサは、基板に絶縁層を介して支持され同基板上にて互いに直交する振動軸方向及び検出軸方向に振動可能な可動部と、可動部を振動軸方向に励振するための電圧が印加される駆動部と、検出軸方向における可動部の変位(振動)を検出する検出部とを備えてなり、可動部を振動軸方向に振動させた状態で、振動軸及び検出軸に直交する軸回りに作用する角速度を同可動部の検出軸方向の変位に基づいて検出するように構成されている(例えば、特許文献1参照。)。
特開平10−103960号公報
This type of semiconductor sensor is supported on a substrate via an insulating layer and can vibrate in a vibration axis direction and a detection axis direction orthogonal to each other on the substrate, and for exciting the movable portion in the vibration axis direction. A drive unit to which a voltage is applied and a detection unit that detects displacement (vibration) of the movable unit in the detection axis direction are provided. An angular velocity acting around an orthogonal axis is configured to be detected based on the displacement of the movable portion in the detection axis direction (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 10-103960

しかしながら、上記半導体センサにおいては、何らかの原因により基板と可動部との間に電位差が生じると、同基板と同可動部との間に静電引力(静電気力)が発生し、これにより可動部の振動特性が変化して検出精度が低下するという問題がある。   However, in the semiconductor sensor, when a potential difference occurs between the substrate and the movable part for some reason, an electrostatic attractive force (electrostatic force) is generated between the substrate and the movable part. There is a problem that the detection accuracy decreases due to changes in vibration characteristics.

これに対し、基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部とを備えた半導体センサにおいて、前記基板と前記可動部とを同電位に維持する同電位維持手段を備えさせることもできる。   On the other hand, in a semiconductor sensor including a movable part supported on a substrate through an insulating layer so as to be able to vibrate, and a detection unit for detecting displacement of the movable part, the substrate and the movable part are at the same potential. It is also possible to provide the same potential maintaining means for maintaining.

これによれば、同電位維持手段により基板と可動部との間が同電位に保たれるため、これらの間に静電引力が発生することがない。従って、可動部の振動特性が安定した検出精度の高い半導体センサが提供される。   According to this, since the same potential is maintained between the substrate and the movable portion by the same potential maintaining means, no electrostatic attractive force is generated between them. Therefore, a semiconductor sensor with high detection accuracy in which the vibration characteristics of the movable part are stable is provided.

ところで、基板と可動部とを同電位にするためには、基板及び可動部に導線を接続し、これらの導線を適当な回路に接続することが必要となる。しかしながら、基板上には絶縁層や可動部等が形成されているため、基板に導線を直接的に接合することが困難な場合が多い。   By the way, in order to make the substrate and the movable portion have the same potential, it is necessary to connect conductive wires to the substrate and the movable portion, and to connect these conductive wires to an appropriate circuit. However, since an insulating layer, a movable portion, and the like are formed on the substrate, it is often difficult to directly join the conductive wire to the substrate.

本発明の特徴は、基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部と、前記基板に絶縁層を介して支持されるとともに同基板と密着する部分とを有してなり同基板の電位を取り出す基板電極とを備えた半導体センサの製造方法において、前記基板電極の製造工程が、前記基板上面の絶縁層に支持され同基板方向に変形可能な前記基板電極となる部材を形成する工程と、前記基板電極となる部材の一部を前記基板に静電接合させる工程とを含んだことにある。   A feature of the present invention is that a movable part supported by a substrate through an insulating layer so as to vibrate, a detection unit for detecting displacement of the movable part, and a substrate supported by the substrate through an insulating layer and the substrate In a method for manufacturing a semiconductor sensor, the substrate electrode manufacturing process is supported by an insulating layer on the upper surface of the substrate and is deformed in the direction of the substrate. A step of forming a member to be the substrate electrode, and a step of electrostatically bonding a part of the member to be the substrate electrode to the substrate.

これによれば、前記基板電極となる部材の一部を前記基板に静電接合させるので、基板電極上に接続導線を接合するという困難な工程を実施することなく、基板電極と基板とを電気的に接続して同電位とすることができる。なお、静電接合とは、静電気力(静電引力)による接合を意味する。この結果、基板電極を介して基板と可動部とを適当な回路に接続し、同基板と可動部とを同電位とすることが容易な半導体センサが得られる。   According to this, since a part of the member to be the substrate electrode is electrostatically bonded to the substrate, the substrate electrode and the substrate can be electrically connected without performing a difficult process of bonding the connecting conductor on the substrate electrode. Can be connected to the same potential. Note that electrostatic bonding means bonding by electrostatic force (electrostatic attractive force). As a result, a semiconductor sensor can be obtained in which the substrate and the movable part are connected to an appropriate circuit via the substrate electrode, and the substrate and the movable part can be easily set to the same potential.

本発明の他の特徴は、基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部と、前記基板に絶縁層を介して支持されるとともに同基板と密着する部分とを有してなり同基板の電位を取り出す基板電極とを備えた半導体センサの製造方法において、前記基板電極の製造工程が、前記基板上面の絶縁層に支持され同基板方向に変形可能な前記基板電極となる部材を形成する工程と、前記基板上面の絶縁層の上面に電圧印加用電極を形成する工程と、前記基板電極となる部材と前記電圧印加用電極との間に電圧を印加して前記基板電極となる部材の一部を前記基板に静電接合させる工程とを含んだことにある。   Another feature of the present invention is that the movable part supported on the substrate through an insulating layer so as to vibrate, a detection unit for detecting the displacement of the movable part, and supported on the substrate through the insulating layer and the same. In a manufacturing method of a semiconductor sensor having a substrate electrode having a portion that is in close contact with the substrate and extracting the potential of the substrate, the manufacturing process of the substrate electrode is supported by an insulating layer on the upper surface of the substrate and the substrate direction Forming a member to be the substrate electrode that can be deformed into a shape, forming a voltage application electrode on the upper surface of the insulating layer on the upper surface of the substrate, and between the member to be the substrate electrode and the voltage application electrode And a step of electrostatically bonding a part of the member to be the substrate electrode to the substrate by applying a voltage to the substrate.

静電接合のために基板電極と基板との間に電圧を印加するには、例えば、上面が露呈している基板電極を使用して同基板電極の電位を所定の正電位又は負電位とし、基板を接地する。この場合、基板に直接的に導線を接合したり電極を接触させることは困難であるから、基板下面を利用して同基板を接地する方法が考えられる。ところが、基板下面には絶縁性の薄膜(酸化膜、窒化膜等)が形成されている場合があり、上記の方法が採用できない場合がある。   In order to apply a voltage between the substrate electrode and the substrate for electrostatic bonding, for example, the substrate electrode whose upper surface is exposed is used to set the potential of the substrate electrode to a predetermined positive potential or negative potential, Ground the board. In this case, since it is difficult to directly join the lead wire or contact the electrode to the substrate, a method of grounding the substrate using the lower surface of the substrate is conceivable. However, an insulating thin film (oxide film, nitride film, etc.) may be formed on the lower surface of the substrate, and the above method may not be employed.

そこで、上記本発明の他の特徴では、絶縁層の上に基板電極となる部材を形成することに加え、電圧印加用の電極を形成する。そして、基板電極となる部材と電圧印加用の電極との間に電圧を印加する。この結果、基板下面が利用できない場合においても、基板電極となる部材と基板との間に電位差を生ぜしめることが可能となり、両者を容易且つ確実に静電接合することが可能となる。   Therefore, in another feature of the present invention, a voltage application electrode is formed in addition to forming a member to be a substrate electrode on the insulating layer. And a voltage is applied between the member used as a board | substrate electrode, and the electrode for voltage application. As a result, even when the lower surface of the substrate cannot be used, a potential difference can be generated between the substrate electrode member and the substrate, and both can be easily and reliably electrostatically bonded.

また、本発明による半導体センサは、基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部と、前記基板と前記可動部とを同電位に維持する同電位維持手段と、を備えた半導体センサにおいて、前記同電位維持手段は、前記基板に絶縁層を介して配設された基板電極を含み、同基板電極の一部が前記基板の上面と静電接合されてなることを特徴としている。   The semiconductor sensor according to the present invention maintains a movable part supported on a substrate through an insulating layer so as to vibrate, a detection part for detecting displacement of the movable part, and the substrate and the movable part at the same potential. The same potential maintaining means includes a substrate electrode disposed on the substrate via an insulating layer, and a part of the substrate electrode is connected to the upper surface of the substrate. It is characterized by being electrostatically bonded.

これによれば、同電位維持手段により基板と可動部とが同電位に保たれるので、これらの間に静電引力が発生することがない。従って、可動部の振動特性が安定した検出精度の高い半導体センサが提供される。また、同電位維持手段は、基板と静電接合された基板電極から基板電位を容易に取出し得る構造を備えているので、基板電極を利用することにより基板と可動部とを同電位に維持することが容易な構造を備えた半導体センサが提供される。   According to this, since the substrate and the movable part are maintained at the same potential by the same potential maintaining means, no electrostatic attractive force is generated between them. Therefore, a semiconductor sensor with high detection accuracy in which the vibration characteristics of the movable part are stable is provided. Further, since the same potential maintaining means has a structure capable of easily extracting the substrate potential from the substrate electrode electrostatically bonded to the substrate, the substrate and the movable portion are maintained at the same potential by using the substrate electrode. A semiconductor sensor having a structure that is easy to handle is provided.

本発明による他の半導体センサは、基板に絶縁層を介して支持されるとともに同基板上で互いに直交する振動軸方向及び検出軸方向に振動可能な可動部と、前記基板に絶縁層を介して配設されるとともに印加される電圧に基づいて前記可動部を前記振動軸方向に振動させる駆動部と、前記基板に絶縁層を介して配設される検出用電極を含むとともに前記可動部の前記検出軸方向の変位を同可動部と同検出用電極とにより構成されるコンデンサの静電容量の変化として検出する検出部と、前記基板と前記可動部とを同電位に維持する同電位維持手段と、を備えた半導体センサにおいて、前記同電位維持手段は、前記基板に絶縁層を介して配設された基板電極を含み、同基板電極の一部が前記基板の上面と静電接合され、同基板電極と前記可動部とが所定の電気回路装置に接続されることにより、同可動部と同基板との間を同電位に維持するとともに前記駆動部に印加される電圧に起因する電流が同可動部に実質的に流れないように同可動部と同基板との間のインピーダンスを所定の高インピーダンスに維持するように構成されたことを特徴とする。   Another semiconductor sensor according to the present invention includes a movable part supported on a substrate via an insulating layer and capable of vibrating in a vibration axis direction and a detection axis direction orthogonal to each other on the substrate, and an insulating layer on the substrate. A drive unit configured to vibrate the movable unit in the vibration axis direction based on a voltage applied and a detection electrode disposed on the substrate via an insulating layer; A detection unit that detects a displacement in the detection axis direction as a change in capacitance of a capacitor constituted by the movable unit and the detection electrode, and a same potential maintaining unit that maintains the substrate and the movable unit at the same potential. And the same potential maintaining means includes a substrate electrode disposed on the substrate via an insulating layer, and a part of the substrate electrode is electrostatically bonded to the upper surface of the substrate, The substrate electrode and the movable part Is connected to a predetermined electric circuit device to maintain the same potential between the movable part and the substrate, and a current caused by the voltage applied to the drive part substantially flows to the movable part. In other words, the impedance between the movable part and the substrate is maintained at a predetermined high impedance.

これによれば、駆動部は、可動部を振動軸方向に振動させる。検出部は、この振動状態にある可動部の検出軸方向の変位を可動部と検出用電極とにより構成されるコンデンサの容量変化として検出する。また、同電位維持手段は、可動部と基板との間を同電位に維持するとともに、駆動部に印加される電圧に基づく電流が可動部に実質的に流れないように可動部と基板との間のインピーダンスを所定の高インピーダンスに維持する。   According to this, the drive part vibrates the movable part in the vibration axis direction. The detection unit detects the displacement in the detection axis direction of the movable unit in the vibration state as a change in the capacitance of the capacitor formed by the movable unit and the detection electrode. Further, the same potential maintaining means maintains the same potential between the movable portion and the substrate, and prevents the current based on the voltage applied to the drive portion from flowing substantially to the movable portion. The impedance between them is maintained at a predetermined high impedance.

従って、可動部と基板との間に静電引力が作用することはなく、可動部の振動特性が安定するとともに、駆動部に印加される電圧に基づく電流が可動部に流れることはなく、同可動部と前記検出用電極とにより構成されるコンデンサの容量変化を検出する検出部の出力が安定する。この結果、検出精度が向上した半導体センサが提供される。   Therefore, electrostatic attraction does not act between the movable part and the substrate, the vibration characteristics of the movable part are stabilized, and current based on the voltage applied to the drive part does not flow to the movable part. The output of the detection unit that detects a change in the capacitance of the capacitor constituted by the movable unit and the detection electrode is stabilized. As a result, a semiconductor sensor with improved detection accuracy is provided.

更に、同電位維持手段は、基板と静電接合された基板電極から基板電位を容易に取出し得る構造を備えているので、基板電極を利用することにより基板と可動部とを同電位に維持することが容易な構造を備えた半導体センサが提供される。   Furthermore, since the same potential maintaining means has a structure in which the substrate potential can be easily taken out from the substrate electrode electrostatically bonded to the substrate, the substrate and the movable part are maintained at the same potential by using the substrate electrode. A semiconductor sensor having a structure that is easy to handle is provided.

以下、本発明の第1実施形態について図1〜図5を参照しつつ説明する。なお、図1(A)は同実施形態に係る半導体センサの平面図、図1(B)は同半導体センサの1−1線に沿った断面図、図2は図1の1−1線に沿った断面を製造工程別に示した図、図3,4は図1の2−2線に沿った断面を製造工程別に示した図、及び図5は本半導体センサの一部をなす電気回路装置の原理を説明するための回路図である。   Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1A is a plan view of the semiconductor sensor according to the embodiment, FIG. 1B is a cross-sectional view taken along line 1-1 of the semiconductor sensor, and FIG. 2 is taken along line 1-1 of FIG. FIGS. 3 and 4 are cross-sectional views taken along line 2-2 of FIG. 1, and FIG. 5 is an electric circuit device forming a part of the semiconductor sensor. It is a circuit diagram for demonstrating the principle of.

この半導体センサは、シリコンからなる略方形状の基板10と、基板10上の周縁部に所定幅を有するように形成されたシリコン酸化膜(絶縁膜)からなる犠牲層20と、犠牲層20の上に形成されたシリコンからなる枠体30と、枠体30の内側に形成されたシリコンからなる可動部(振動子)40と、櫛歯状電極50a,50b,60a,60bと、基板10の電位を取出すための基板電極70とを備えている。なお、上記シリコンはP形又はN形とされている。   This semiconductor sensor includes a substantially rectangular substrate 10 made of silicon, a sacrificial layer 20 made of a silicon oxide film (insulating film) formed to have a predetermined width at the peripheral portion on the substrate 10, and a sacrificial layer 20. A frame 30 made of silicon formed thereon, a movable part (vibrator) 40 made of silicon formed inside the frame 30, comb-like electrodes 50 a, 50 b, 60 a, 60 b, and a substrate 10 And a substrate electrode 70 for taking out a potential. The silicon is P-type or N-type.

可動部40は、複数の貫通孔40aを備え、枠体30の内側位置において梁11a〜11dによりX軸方向(図1(A)の左右方向)及びY軸方向(図1(A)の上下方向)に振動可能となるように基板10に空間を挟んで対向する状態(同基板10から僅かな距離だけ浮いた状態)に支持されている。   The movable portion 40 includes a plurality of through-holes 40a, and the beams 11a to 11d are positioned at the inner side of the frame body 30 by the beams 11a to 11d in the X-axis direction (left and right direction in FIG. 1A) and Y-axis direction (up and down in FIG. 1A). The substrate 10 is supported in a state of being opposed to the substrate 10 with a space in between (a state where the substrate 10 is lifted by a small distance).

可動部40と同一材料からなる略L字状の梁11a〜11dは、各内側端にて可動部40に接続されるとともに各外側端にて基板10上に犠牲層20を挟んで形成されたベース部12a〜12dに接続されていて、可動部40と同様に基板10から僅かな距離だけ浮いた状態となっている。また、梁11a〜11dであって枠体30の内側面30aから外側に延びる部分の側壁と枠体30との間、及びベース部12a〜12dの側壁と枠体30との間には、一定幅の空間が設けられ、その空間は基板10の上面にまで至っている。ベース部12aの上にはアルミニウム等の導電金属からなる方形状の電極パッド13が形成されていて、その上面には図示しないアルミニウム等からなる接続導線(ワイヤ)が接合されている。   The substantially L-shaped beams 11a to 11d made of the same material as the movable portion 40 are connected to the movable portion 40 at each inner end and are formed on the substrate 10 with the sacrificial layer 20 sandwiched at each outer end. It is connected to the base portions 12 a to 12 d and is in a state of being lifted by a slight distance from the substrate 10 like the movable portion 40. In addition, the beam 11a to 11d is fixed between the side wall of the portion extending outward from the inner side surface 30a of the frame body 30 and the frame body 30, and between the side wall of the base portions 12a to 12d and the frame body 30. A space having a width is provided, and the space reaches the upper surface of the substrate 10. A rectangular electrode pad 13 made of a conductive metal such as aluminum is formed on the base portion 12a, and a connecting wire (wire) made of aluminum or the like (not shown) is joined to the upper surface thereof.

基板10の上面には同基板10から可動部40に向けて突出する突起部21が設けられている。この突起部21は、可動部40が基板上で互いに直交するX軸(振動軸)及びY軸(検出軸)の両軸に直交する方向(Z軸方向)に振動したときに当接するストッパとして機能し、鏡面となっている可動部40の下面(以下、可動部40の下面とは「可動部40の基板10側の面又は犠牲層20側の面」をいう。)が、鏡面となっている基板10の上面(以下、基板10の上面とは「基板10の可動部40側の面又は犠牲層20側の面」をいう。)と面接触して固着状態となることを防止するために設けられている。   A protrusion 21 that protrudes from the substrate 10 toward the movable portion 40 is provided on the upper surface of the substrate 10. The protrusion 21 serves as a stopper that abuts when the movable portion 40 vibrates in a direction (Z-axis direction) orthogonal to both the X-axis (vibration axis) and the Y-axis (detection axis) orthogonal to each other on the substrate. The lower surface of the movable portion 40 that functions and is a mirror surface (hereinafter, the lower surface of the movable portion 40 refers to the “surface on the substrate 10 side of the movable portion 40 or the surface on the sacrificial layer 20 side”) is the mirror surface. The substrate 10 is prevented from coming into contact with the upper surface of the substrate 10 (hereinafter, the upper surface of the substrate 10 is “the surface of the substrate 10 on the movable part 40 side or the surface of the sacrificial layer 20”). It is provided for.

可動部40のX軸方向各外側には、櫛歯状電極41a,41bが同可動部40と一体的に形成されていて、可動部40と同様に基板10から僅かな距離だけ浮いた状態となっている。この櫛歯状電極41a,41bは、X軸方向外側に延設されるとともにY軸方向に等間隔に配置された複数の電極指をそれぞれ備えている。   Comb-like electrodes 41 a and 41 b are formed integrally with the movable portion 40 on the outer sides of the movable portion 40 in the X-axis direction, and are floated from the substrate 10 by a small distance like the movable portion 40. It has become. The comb-like electrodes 41a and 41b respectively include a plurality of electrode fingers that extend outward in the X-axis direction and are arranged at equal intervals in the Y-axis direction.

可動部40のY軸方向各外側には、櫛歯状電極42a,42bが同可動部40と一体的に形成されていて、可動部40と同様に基板10から僅かな距離だけ浮いた状態となっている。この櫛歯状電極42a,42bは、Y軸方向外側に延設されるとともにX軸方向に等間隔に配置された複数の電極指をそれぞれ備えている。   Comb-like electrodes 42a and 42b are formed integrally with the movable portion 40 on the outer sides in the Y-axis direction of the movable portion 40, and are in a state of being lifted by a slight distance from the substrate 10 like the movable portion 40. It has become. The comb-shaped electrodes 42a and 42b respectively include a plurality of electrode fingers that extend outward in the Y-axis direction and are arranged at equal intervals in the X-axis direction.

櫛歯状電極50a,50bは、可動部40のX軸方向外側にそれぞれ形成されている。各櫛歯状電極50a,50bは、X軸方向に延設されるとともにY軸方向に等間隔に配置された複数の電極指を備えていて、これらの各電極指は櫛歯状電極41a,41bの各電極指間の幅方向(Y軸方向)中心位置に侵入している。   The comb-like electrodes 50a and 50b are respectively formed on the outer side of the movable portion 40 in the X-axis direction. Each comb-like electrode 50a, 50b includes a plurality of electrode fingers that extend in the X-axis direction and are equally spaced in the Y-axis direction, and each of these electrode fingers includes a comb-like electrode 41a, It penetrates into the center position in the width direction (Y-axis direction) between the electrode fingers 41b.

また、各櫛歯状電極50a,50bは、X軸方向各外側においてパッド部51a,51bに接続されている。パッド部51a,51bは、犠牲層20の上面に方形状に形成されていて、その周壁と枠体30との間には、一定幅の空間が設けられ、その空間は基板10の上面にまで至っている。パッド部51a,51bの上面には、電極パッド13と同一平面内に位置する(基板10の上面から同じ高さとなる)ようにアルミニウム等の導電金属で方形状の電極パッド52a,52bが設けられていて、その上面には図示しないアルミニウム等からなる接続導線(ワイヤ)が接合されている。かかる櫛歯状電極50a,50bは、櫛歯状電極41a,41bとともに可動部40に対する駆動部を構成し、駆動用信号の印加によって可動部40を静電引力によりX軸方向に振動させる(励振する)。   The comb-like electrodes 50a and 50b are connected to the pad portions 51a and 51b on the outer sides in the X-axis direction. The pad portions 51 a and 51 b are formed in a rectangular shape on the upper surface of the sacrificial layer 20, and a space having a certain width is provided between the peripheral wall and the frame body 30, and the space extends to the upper surface of the substrate 10. Has reached. On the upper surfaces of the pad portions 51a and 51b, rectangular electrode pads 52a and 52b made of a conductive metal such as aluminum are provided so as to be located in the same plane as the electrode pad 13 (same height from the upper surface of the substrate 10). A connecting conductor (wire) made of aluminum or the like (not shown) is joined to the upper surface. The comb-shaped electrodes 50a and 50b constitute a driving unit for the movable unit 40 together with the comb-shaped electrodes 41a and 41b, and vibrate the movable unit 40 in the X-axis direction by electrostatic attraction by applying a driving signal (excitation). To do).

櫛歯状電極60a,60bは、可動部40のY軸方向外側にそれぞれ形成されている。各櫛歯状電極60a,60bは、Y軸方向に延設されるとともにX軸方向に等間隔に配置された複数の電極指を備えていて、これらの各電極指は櫛歯状電極42a,42bの各電極指間の幅方向(X軸方向)中心位置に侵入している。   The comb-like electrodes 60a and 60b are respectively formed on the outer side of the movable portion 40 in the Y-axis direction. Each comb-like electrode 60a, 60b includes a plurality of electrode fingers that extend in the Y-axis direction and are equally spaced in the X-axis direction, and each of these electrode fingers includes the comb-like electrode 42a, It penetrates into the center position in the width direction (X-axis direction) between the electrode fingers 42b.

また、各櫛歯状電極60a,60bは、Y軸方向各外側においてパッド部61a,61bに接続されている。パッド部61a,61bは、犠牲層20の上面に方形状に形成されていて、その周壁と枠体30との間には、一定幅の空間が設けられ、その空間は基板10の上面にまで至っている。パッド部61a,61bの上面には、電極パッド13と同一平面内に位置するようにアルミニウム等の導電金属で方形状の電極パッド62a,62bが設けられていて、その上面には図示しないアルミニウム等からなる接続導線(ワイヤ)が接合されている。かかる櫛歯状電極60a,60bは、櫛歯状電極42a,42bとともに可動部40に対する検出部を構成し、可動部40のY軸方向の振動(変位)を、櫛歯状電極60aと櫛歯状電極42aの間及び櫛歯状電極60bと櫛歯状電極42bとの間に構成されるコンデンサの容量変化として検出するために用いられる。   The comb-like electrodes 60a and 60b are connected to the pad portions 61a and 61b on the outer sides in the Y-axis direction. The pad portions 61 a and 61 b are formed in a rectangular shape on the upper surface of the sacrificial layer 20, and a space having a certain width is provided between the peripheral wall and the frame body 30, and the space extends to the upper surface of the substrate 10. Has reached. On the upper surface of the pad portions 61a and 61b, rectangular electrode pads 62a and 62b made of a conductive metal such as aluminum are provided so as to be located in the same plane as the electrode pad 13, and aluminum or the like (not shown) is provided on the upper surface. The connection conducting wire (wire) which consists of is joined. The comb-shaped electrodes 60a and 60b constitute a detection unit for the movable portion 40 together with the comb-shaped electrodes 42a and 42b, and the vibration (displacement) of the movable portion 40 in the Y-axis direction is detected by the comb-shaped electrode 60a and the comb teeth. This is used to detect a change in capacitance of a capacitor formed between the interdigital electrodes 42a and between the interdigital electrodes 60b and 42b.

基板電極70は、図4(B)にも示したように、可動部40と同一材料(シリコン)からなり、可動部40等から離れた位置に独立して設けられていて、パッド部70a、可撓性の変形部70b、及び基板接合部70cから構成されている。また、基板電極70の周壁と枠体30との間には、一定幅の空間が設けられ、その空間は基板10の上面にまで至っている。   As shown in FIG. 4B, the substrate electrode 70 is made of the same material (silicon) as the movable portion 40 and is provided independently at a position away from the movable portion 40 and the like. It is composed of a flexible deformation portion 70b and a substrate bonding portion 70c. In addition, a space having a certain width is provided between the peripheral wall of the substrate electrode 70 and the frame body 30, and the space reaches the upper surface of the substrate 10.

パッド部70aは、方形状であって犠牲層20の上面に形成されていて、その上面には電極パッド13と同一平面内に位置するようにアルミニウム等の導電金属で方形状の電極パッド71が設けられている。電極パッド71の上面にはアルミニウム等からなる接続導線(ワイヤ)Wが接合されている。変形部70bは、パッド部70aからX軸方向に長く延びながら基板10側に変形し、方形状の基板接合部70cに接続されている。基板接合部70cは、基板10の上面に静電接合(静電引力により密着)されていて、これにより、基板電極70と基板10とは電気的に接続され同電位となっている。   The pad portion 70a is rectangular and is formed on the upper surface of the sacrificial layer 20, and a rectangular electrode pad 71 made of a conductive metal such as aluminum is placed on the upper surface of the pad portion 70a so as to be in the same plane as the electrode pad 13. Is provided. A connecting wire (wire) W made of aluminum or the like is joined to the upper surface of the electrode pad 71. The deforming portion 70b is deformed toward the substrate 10 while extending from the pad portion 70a in the X-axis direction, and is connected to the rectangular substrate bonding portion 70c. The substrate bonding portion 70c is electrostatically bonded (adhered by electrostatic attraction) to the upper surface of the substrate 10, and thereby the substrate electrode 70 and the substrate 10 are electrically connected and have the same potential.

枠体30の上面には、梁11a〜11d、可動部40、櫛歯状電極41a,41b,42a,42b、櫛歯状電極50a,50b,60a,60b、及び基板電極70を覆うように方形状のガラス蓋(図示省略)が固着されている。これにより、可動部40は、基板10,犠牲層20、枠体30と前記ガラス蓋とにより形成される密閉空間内で振動するようになっている。   The upper surface of the frame 30 covers the beams 11a to 11d, the movable portion 40, the comb-shaped electrodes 41a, 41b, 42a and 42b, the comb-shaped electrodes 50a, 50b, 60a and 60b, and the substrate electrode 70. A shaped glass lid (not shown) is fixed. Thereby, the movable part 40 vibrates in a sealed space formed by the substrate 10, the sacrificial layer 20, the frame body 30 and the glass lid.

次に、上記のように構成した半導体センサの製造方法について図2〜図4を参照しつつ工程順に説明する。
(第1工程)
先ず、図2(A)及び図3(A)に示したように、シリコンからなる基板10と、その上面上に約1μmの厚さのシリコン酸化膜である犠牲層20と、約10μmのシリコンからなる上層31とを積層してなるSOI(Silicon-on-Insulator)ウエハの上面全体にシリコン酸化膜32を形成する。
Next, the manufacturing method of the semiconductor sensor configured as described above will be described in the order of steps with reference to FIGS.
(First step)
First, as shown in FIGS. 2A and 3A, a substrate 10 made of silicon, a sacrificial layer 20 which is a silicon oxide film having a thickness of about 1 μm on the upper surface thereof, and silicon having a thickness of about 10 μm. A silicon oxide film 32 is formed on the entire top surface of an SOI (Silicon-on-Insulator) wafer formed by laminating an upper layer 31 made of

(第2工程)
次に、図2(B)及び図3(B)に示したように、酸化膜32の上面であって可動部40(貫通孔40aを除く)、櫛歯状電極41a,41b,42a,42b,50a,50b,60a,60b、パッド部51a,51b,61a,61b、梁11a〜11d、ベース部12a〜12d、枠体30、及び基板電極70に相当する部分とこの部分に僅かな幅を加えた部分とをレジスト膜Rにてマスクする。
(Second step)
Next, as shown in FIG. 2B and FIG. 3B, on the upper surface of the oxide film 32, the movable portion 40 (excluding the through hole 40a), the comb-like electrodes 41a, 41b, 42a, 42b. , 50a, 50b, 60a, 60b, pad portions 51a, 51b, 61a, 61b, beams 11a-11d, base portions 12a-12d, frame 30, and a portion corresponding to the substrate electrode 70 and a slight width in this portion. The added portion is masked with the resist film R.

(第3工程)
次に、図2(C)及び図3(C)に示したように、上層31及び酸化膜32をRIE(反応性イオンエッチング)等でエッチングして、後に可動部40となる部分(以下「可動部層40b」という。)に貫通孔40aを形成するとともに、犠牲層20上にベース部12a〜12d、櫛歯状電極50a,50b,60a,60b、パッド部51a,51b,61a,61b、及び枠体30を形成し、可動部層40b、櫛歯状電極41a,41b,42a,42b、梁11a〜11d、及び基板電極70に相当する部分を残す。
(Third step)
Next, as shown in FIG. 2C and FIG. 3C, the upper layer 31 and the oxide film 32 are etched by RIE (reactive ion etching) or the like, and a portion that will later become the movable portion 40 (hereinafter, “ A through-hole 40a is formed in the movable part layer 40b "), the base parts 12a to 12d, the comb-like electrodes 50a, 50b, 60a, 60b, the pad parts 51a, 51b, 61a, 61b, The frame 30 is formed, and the movable portion layer 40b, the comb-like electrodes 41a, 41b, 42a, 42b, the beams 11a to 11d, and the portions corresponding to the substrate electrodes 70 are left.

(第4工程)
次に、図2(D)及び図3(D)に示したように、レジストRを除去し、次いで、酸化シリコンを溶解するがシリコンを溶解することのないフッ酸水溶液(エッチング液)で満たされた槽内にウエハを浸漬し、可動部層40b、櫛歯状電極41a,41b,42a,42b、梁11a〜11d、基板電極70の変形部70b及び基板接合部70cと基板10とに挟まれる犠牲層20をエッチングして除去する。これにより、可動部40、櫛歯状電極41a,41b,42a,42b、及び梁11a〜11dが形成される。また、基板電極70となる部分については、一部が犠牲層20の上面に残されてパッド部70aとなり、他の部分が基板10から浮いた状態となって変形部70b及び基板接合部70cとなる。なお、この時点で突起部21が可動部40の下部に形成される。
(4th process)
Next, as shown in FIGS. 2D and 3D, the resist R is removed and then filled with a hydrofluoric acid aqueous solution (etching solution) that dissolves silicon oxide but does not dissolve silicon. The wafer is immersed in the tank, and is sandwiched between the movable part layer 40b, the comb-like electrodes 41a, 41b, 42a, 42b, the beams 11a to 11d, the deformed part 70b of the substrate electrode 70, the substrate bonding part 70c, and the substrate 10. The sacrifice layer 20 to be etched is removed by etching. Thereby, the movable part 40, the comb-tooth electrodes 41a, 41b, 42a, 42b, and the beams 11a to 11d are formed. Further, as for the portion that becomes the substrate electrode 70, a part is left on the upper surface of the sacrificial layer 20 to become the pad portion 70 a, and the other portion is lifted from the substrate 10, and the deformed portion 70 b and the substrate bonding portion 70 c Become. At this time, the protruding portion 21 is formed below the movable portion 40.

(第5工程)
次いで、図2(E)及び図3(E)に示したように、アルミ膜を電極パッド13,52a,52b,61a,61b,71に相当する部分にスパッタリング法等により形成し、電極パッド13,52a,52b,62a,62b,71を形成する。
(5th process)
Next, as shown in FIGS. 2E and 3E, an aluminum film is formed on the portions corresponding to the electrode pads 13, 52a, 52b, 61a, 61b, 71 by a sputtering method or the like. , 52a, 52b, 62a, 62b, 71 are formed.

(第6工程)
次に、図4(A)に示したように、上記の状態となったウエハを金属ステージ90の上に載せ、この金属ステージ90と基板電極70の電極パッド71との間に電圧を印加する。これにより、基板電極70の変形部70b及び基板接合部70cと基板10との間に静電引力が発生し、変形部70bが基板10方向に変形する。この結果、鏡面状態である基板10の上面と鏡面状態である基板接合部70cとの間がファンデルワールス力により密着(静電接合)する。なお、この金属ステージ90に載置された状態で、半導体センサとしての機能チェックも実施される。
(6th process)
Next, as shown in FIG. 4A, the wafer in the above state is placed on the metal stage 90, and a voltage is applied between the metal stage 90 and the electrode pad 71 of the substrate electrode 70. . As a result, electrostatic attraction is generated between the deformable portion 70b and the substrate bonding portion 70c of the substrate electrode 70 and the substrate 10, and the deformable portion 70b is deformed in the direction of the substrate 10. As a result, the upper surface of the substrate 10 in the mirror surface state and the substrate bonding portion 70c in the mirror surface state are in close contact (electrostatic bonding) by van der Waals force. In addition, the function check as a semiconductor sensor is also implemented in the state mounted on this metal stage 90.

(第7工程)
次いで、電極パッド13,52a,52b,62a,62b,71の上面にアルミニウムからなる接続導線(ワイヤ)Wを超音波ワイヤボンディング法等により接合する。そして、これらの接続導線を電気回路装置(図示省略)の端子と接続する。
(第8工程)
最後に、真空中において前述したガラス蓋(図示省略)を枠体30上面に陽極接合等により固着する。
(Seventh step)
Next, a connecting wire (wire) W made of aluminum is bonded to the upper surfaces of the electrode pads 13, 52a, 52b, 62a, 62b, 71 by an ultrasonic wire bonding method or the like. And these connection conducting wires are connected with the terminal of an electric circuit device (illustration omitted).
(8th step)
Finally, the above-described glass lid (not shown) is fixed to the upper surface of the frame 30 by anodic bonding or the like in a vacuum.

次に、上記のように構成した半導体センサの使用態様について説明すると、電気回路装置は、可動部40をその固有振動数f0でX軸方向に一定振幅で振動させるために、互いに逆相の駆動用信号を電極パッド52a,52bにそれぞれ供給する。また、可動部40のY軸方向の振動を検出するために、互いに逆相の検出用信号を電極パッド62a,62bに供給する。   Next, the usage mode of the semiconductor sensor configured as described above will be described. The electric circuit device drives the movable unit 40 in opposite phases to vibrate the movable unit 40 with its natural frequency f0 and a constant amplitude in the X-axis direction. A signal is supplied to the electrode pads 52a and 52b, respectively. In addition, in order to detect the vibration of the movable portion 40 in the Y-axis direction, detection signals having phases opposite to each other are supplied to the electrode pads 62a and 62b.

以上により、可動部40は前記駆動部に発生する静電引力により固有振動数f0でX軸方向に一定振幅で振動し、この状態においてX,Y軸に直行するZ軸回りの角速度が働くと、可動部40はコリオリ力により同角速度に比例した振幅でY軸方向にも振動する。この可動部40のY軸方向の振動に伴い、可動部40に接続された櫛歯状電極42a,42bもY軸方向に振動するため、櫛歯状電極42a,60aにおける静電容量と、櫛歯状電極42b,60bにおける静電容量とは互いに逆方向に変化する。この静電容量の変化を表す信号が、静電容量信号として電極パッド13を介して電気回路装置に入力される。電気回路装置は、この静電容量信号を用いて前記Z軸回りの角速度を導出する。   As described above, the movable part 40 vibrates with a constant amplitude in the X-axis direction at the natural frequency f0 due to the electrostatic attractive force generated in the driving part, and in this state, the angular velocity around the Z-axis perpendicular to the X and Y axes acts. The movable portion 40 also vibrates in the Y-axis direction with an amplitude proportional to the angular velocity due to the Coriolis force. As the movable portion 40 vibrates in the Y-axis direction, the comb-shaped electrodes 42a and 42b connected to the movable portion 40 also vibrate in the Y-axis direction. Therefore, the capacitance of the comb-shaped electrodes 42a and 60a and the comb The electrostatic capacitances in the tooth-like electrodes 42b and 60b change in opposite directions. A signal representing the change in capacitance is input to the electric circuit device through the electrode pad 13 as a capacitance signal. The electric circuit device uses this capacitance signal to derive the angular velocity about the Z axis.

ここで、上記電気回路装置の具体例について図5を参照しつつ説明する。なお、図5に示した電気回路装置は、簡単のために、上記電極パッド13,52a,62a,71を使用するものとしたが、電極パッド13,52a,52b,62a,62b,71の全てを使用する上記電気回路装置も原理的には図5に図示したものと同様である。   Here, a specific example of the electric circuit device will be described with reference to FIG. The electric circuit device shown in FIG. 5 uses the electrode pads 13, 52a, 62a, 71 for the sake of simplicity, but all of the electrode pads 13, 52a, 52b, 62a, 62b, 71 are used. The above-described electric circuit device using the above is also similar in principle to that shown in FIG.

この電気回路装置においては、電圧v、周波数ωの検出用高周波電源Vが電極パッド62aに接続されている。この電極パッド62aは、櫛歯状電極60aと櫛歯状電極42a(可動部40)との間に形成されるコンデンサC10を介して電極パッド13に接続されている。電極パッド13は、オペアンプOP1のマイナス側入力端子に接続されている。オペアンプOP1の出力端子は帰還抵抗rを介してオペアンプOP1のマイナス側入力端子に接続され、プラス側入力端子は接地されている。一方、電圧vd、周波数ωdの駆動用高周波電源Vdが、電極パッド52aに接続されている。電極パッド52aは、櫛歯状電極50a(及びパッド部51a)と基板10との間に形成されるコンデンサC20を介して基板電極70の電極パッド71に接続され、電極パッド71は接地されている。   In this electric circuit device, a detection high-frequency power source V having a voltage v and a frequency ω is connected to the electrode pad 62a. The electrode pad 62a is connected to the electrode pad 13 via a capacitor C10 formed between the comb-shaped electrode 60a and the comb-shaped electrode 42a (movable part 40). The electrode pad 13 is connected to the negative input terminal of the operational amplifier OP1. The output terminal of the operational amplifier OP1 is connected to the negative input terminal of the operational amplifier OP1 through the feedback resistor r, and the positive input terminal is grounded. On the other hand, a driving high-frequency power source Vd having a voltage vd and a frequency ωd is connected to the electrode pad 52a. The electrode pad 52a is connected to the electrode pad 71 of the substrate electrode 70 via a capacitor C20 formed between the comb-like electrode 50a (and the pad portion 51a) and the substrate 10, and the electrode pad 71 is grounded. .

以上により、抵抗rには可動部40に加わる角速度により変動するコンデンサC10の容量に比例した電流が流れ、オペアンプOP1の出力端子には同コンデンサC10の容量に比例した電圧(−jωrvC)が出力される。電気回路装置は、このオペアンプOP1の出力を使用して角速度を検出する。   As a result, a current proportional to the capacity of the capacitor C10, which fluctuates depending on the angular velocity applied to the movable portion 40, flows through the resistor r, and a voltage (-jωrvC) proportional to the capacity of the capacitor C10 is output to the output terminal of the operational amplifier OP1. The The electric circuit device detects the angular velocity using the output of the operational amplifier OP1.

また、オペアンプOP1のマイナス側入力端子は可動部40の電極パッド13に接続され、オペアンプOP1のプラス側入力端子は接地されるとともに、基板10は基板電極70の電極パッド71を介して接地されている。従って、基板10と可動部40はオペアンプOP1のイマジナリショートによって同電位に維持される。更に、基板10と可動部40との間のインピーダンスはオペアンプOP1のプラス側入力端子とマイナス側入力端子間のインピーダンスとなるため、実質的に無限大となる。   The negative input terminal of the operational amplifier OP1 is connected to the electrode pad 13 of the movable portion 40, the positive input terminal of the operational amplifier OP1 is grounded, and the substrate 10 is grounded via the electrode pad 71 of the substrate electrode 70. Yes. Therefore, the substrate 10 and the movable part 40 are maintained at the same potential by the imaginary short of the operational amplifier OP1. Furthermore, since the impedance between the substrate 10 and the movable portion 40 is the impedance between the plus side input terminal and the minus side input terminal of the operational amplifier OP1, it is substantially infinite.

以上に説明したように、第1実施形態に係る半導体センサにおいては、接地される基板電極70及び上記結線がなされたオペアンプOP1(同電位維持手段の一部)により基板10と可動部40との間が同電位に維持されるため、基板10と可動部40との間に静電引力が発生せず、可動部40の振動特性が安定する。また、基板10と可動部40との間のインピーダンスは無限大に維持されるため、駆動用高周波電源Vdに起因する電流が基板経由で可動部40に流れ込むことがなく、櫛歯状電極42a,60aと櫛歯状電極42b,60bにおける静電容量の変化が正確に検出され、その結果、角速度が正確に検出される。   As described above, in the semiconductor sensor according to the first embodiment, the substrate 10 and the movable unit 40 are connected by the grounded substrate electrode 70 and the operational amplifier OP1 (part of the same potential maintaining means) connected as described above. Since the gap is maintained at the same potential, no electrostatic attractive force is generated between the substrate 10 and the movable portion 40, and the vibration characteristics of the movable portion 40 are stabilized. Further, since the impedance between the substrate 10 and the movable portion 40 is maintained infinite, current caused by the driving high-frequency power source Vd does not flow into the movable portion 40 via the substrate, and the comb-like electrodes 42a, The change in electrostatic capacitance between 60a and the comb-like electrodes 42b and 60b is accurately detected, and as a result, the angular velocity is accurately detected.

また、基板電極70(電極パッド71)は、他の電極の電極パッド13,52a,52b,62a,62bとともに同一平面内に位置するように形成されているので、これらに接続導線を接合する際の作業が簡単になるという利点を有している。更に、この製造方法においては、基板電極70の一部(基板接合部70c)を基板10の上面と静電接合するので、基板電極70と基板10とを簡単な工程により確実に電気的に接合することが可能となるという利点を有している。   Further, since the substrate electrode 70 (electrode pad 71) is formed so as to be located in the same plane together with the electrode pads 13, 52a, 52b, 62a and 62b of the other electrodes, when connecting the connecting conductors to them, This has the advantage of simplifying the work. Furthermore, in this manufacturing method, since a part of the substrate electrode 70 (substrate bonding portion 70c) is electrostatically bonded to the upper surface of the substrate 10, the substrate electrode 70 and the substrate 10 are reliably electrically bonded by a simple process. It has the advantage that it can be done.

次に、本発明による半導体センサの第2実施形態について図6を参照しながら説明すると、この第2実施形態は、構造に関しては、基板電極が二つ設けられている点においてのみ、基板電極70が一つだけ設けられる第1実施形態と異なっている。従って、以下、図6において第1実施形態と同一の部分には図1と同一の参照符号を付し、その詳細説明を省略する。   Next, a second embodiment of the semiconductor sensor according to the present invention will be described with reference to FIG. 6. The second embodiment is that the substrate electrode 70 is provided only in that two substrate electrodes are provided in terms of structure. This is different from the first embodiment in which only one is provided. Accordingly, in FIG. 6, the same reference numerals as those in FIG. 1 are given to the same portions as those in the first embodiment, and detailed description thereof will be omitted.

第2実施形態においては、シリコンからなる基板電極80が、基板電極70の近傍位置であって可動部40等とは離れた位置に独立して形成されている。基板電極80は、構造に関し基板電極70と同様であり、パッド部80a、可撓性の変形部80b、及び基板接合部80cとから構成されていて、その周壁と枠体30との間には基板10の上面にまで至る一定幅の空間が形成されている。   In the second embodiment, the substrate electrode 80 made of silicon is independently formed at a position in the vicinity of the substrate electrode 70 and away from the movable portion 40 and the like. The substrate electrode 80 is the same as the substrate electrode 70 in terms of structure, and includes a pad portion 80a, a flexible deformation portion 80b, and a substrate bonding portion 80c, and between the peripheral wall and the frame body 30. A space having a certain width extending to the upper surface of the substrate 10 is formed.

パッド部80aは、犠牲層20の上面に方形状に形成されていて、その上面にはアルミニウム等の導電金属で方形状の電極パッド81が電極パッド13と同一平面内に位置するように形成されている。変形部80bは、パッド部80aからX軸方向に長く延びながら基板10側に変形し、方形状の基板接合部80cに接続され、基板接合部80cは基板10に静電接合(密着)されている。   The pad portion 80 a is formed in a rectangular shape on the upper surface of the sacrificial layer 20, and a rectangular electrode pad 81 made of a conductive metal such as aluminum is formed on the upper surface so as to be positioned in the same plane as the electrode pad 13. ing. The deforming portion 80b is deformed to the substrate 10 side while extending from the pad portion 80a in the X-axis direction, and is connected to the square substrate bonding portion 80c. The substrate bonding portion 80c is electrostatically bonded (adhered) to the substrate 10. Yes.

次に、上記のように構成した第2実施形態に係る半導体センサの製造方法について説明すると、この製造方法は、基板電極80を基板電極70と同時に形成する点、及び基板電極70の基板接合部70cを基板10に静電接合させる際に、基板電極70と基板電極80との間に電圧を印加する点においてのみ第1実施形態に係る半導体センサの製造方法と異なっている。   Next, the manufacturing method of the semiconductor sensor according to the second embodiment configured as described above will be described. This manufacturing method includes the point that the substrate electrode 80 is formed simultaneously with the substrate electrode 70, and the substrate bonding portion of the substrate electrode 70. When electrostatically bonding 70 c to the substrate 10, the semiconductor sensor manufacturing method according to the first embodiment is different only in that a voltage is applied between the substrate electrode 70 and the substrate electrode 80.

具体的には、先ず第1実施形態の第1,第2工程と同一の工程を実施する。このとき、SOI上に形成するマスクを、基板電極80に相当する部分及びその部分に僅かな幅だけ加えた部分の上部にも残存するように形成しておく。   Specifically, first, the same steps as the first and second steps of the first embodiment are performed. At this time, the mask formed on the SOI is formed so as to remain on the portion corresponding to the substrate electrode 80 and on the portion obtained by adding a slight width to the portion.

次いで、第1実施形態の第3工程と同様のRIE工程を実施し、第1実施形態の第4工程と同様の犠牲層20のエッチング工程を実施する。この結果、可動部層40b、櫛歯状電極41a,41b,42a,42b、及び梁11a〜11d、と基板10とに挟まれる犠牲層20が除去され、可動部40の下部には突起部21が形成される。また、基板電極70,80となる部分については、変形部70b,80b、基板接合部70c,80cと基板10との間に挟まれる犠牲層20が除去される結果、一部が犠牲層20の上面に残されてパッド部70a,80aとなり、他の部分が基板10から浮いた状態となって変形部70b,80b及び基板接合部70c,80cとなる。その後、アルミ膜を所定の部位に成膜して、電極パッド13,52a,52b,62a,62b,71,81を形成する。   Next, an RIE process similar to the third process of the first embodiment is performed, and an etching process of the sacrificial layer 20 similar to the fourth process of the first embodiment is performed. As a result, the movable portion layer 40b, the comb-like electrodes 41a, 41b, 42a, 42b, the beams 11a to 11d, and the sacrificial layer 20 sandwiched between the substrate 10 are removed, and the projecting portion 21 is formed below the movable portion 40. Is formed. Further, the portions that become the substrate electrodes 70 and 80 are partially removed from the sacrificial layer 20 as a result of the removal of the sacrificial layer 20 sandwiched between the deformed portions 70b and 80b and the substrate bonding portions 70c and 80c and the substrate 10. The pad portions 70a and 80a are left on the upper surface, and the other portions are lifted from the substrate 10 to become deformed portions 70b and 80b and substrate bonding portions 70c and 80c. Thereafter, an aluminum film is formed on a predetermined portion to form electrode pads 13, 52a, 52b, 62a, 62b, 71, 81.

次に、図6(A)に破線で示したように、基板電極70の電極パッド71と基板電極80の電極パッド81との間に電圧を印加する。これにより、基板電極70と基板10との間には、パッド部70aの下部に存在する犠牲層20を介して電位差が生じ、基板電極80と基板10との間にはパッド部80aの下部に存在する犠牲層20を介して電位差が生じる。この結果、変形部70b,80b、及び基板接合部70c,80cの各々と基板10との間に静電引力が発生し、変形部71b,81bの各々が基板10に向けて変形するため、基板10の上面と基板接合部70cの下面との間、及び基板10の上面と基板接合部80cの下面とがファンデルワールス力により密着(静電接合)する。   Next, a voltage is applied between the electrode pad 71 of the substrate electrode 70 and the electrode pad 81 of the substrate electrode 80 as indicated by a broken line in FIG. As a result, a potential difference is generated between the substrate electrode 70 and the substrate 10 via the sacrificial layer 20 existing below the pad portion 70a, and between the substrate electrode 80 and the substrate 10, there is a portion below the pad portion 80a. A potential difference is generated through the existing sacrificial layer 20. As a result, electrostatic attraction is generated between each of the deformable portions 70b and 80b and the substrate joint portions 70c and 80c and the substrate 10, and each of the deformable portions 71b and 81b is deformed toward the substrate 10. 10 and the lower surface of the substrate bonding portion 70c, and the upper surface of the substrate 10 and the lower surface of the substrate bonding portion 80c are brought into close contact (electrostatic bonding) by van der Waals force.

次いで、電極パッド13,52a,52b,62a,62b,71の上面にアルミニウムからなる接続導線(ワイヤ)を超音波ワイヤボンディング法等により接合する。そして、これらの接続導線を電気回路装置の端子と接続する。最後に、真空中において前述したガラス蓋(図示省略)を枠体30上面に陽極接合等により固着する。   Next, a connecting conductor (wire) made of aluminum is bonded to the upper surfaces of the electrode pads 13, 52a, 52b, 62a, 62b, 71 by an ultrasonic wire bonding method or the like. And these connection conducting wires are connected with the terminal of an electric circuit device. Finally, the above-described glass lid (not shown) is fixed to the upper surface of the frame 30 by anodic bonding or the like in a vacuum.

以上、説明したように、本発明の第2実施形態に係る半導体センサにおいては、二つの基板電極70,80となる部分を形成し、これらの電極パッド71,81間に電位差を与えて、基板接合部70c,80cと基板10とを密着(静電接合)させる。従って、基板10の下面に酸化膜或いは窒化膜等の絶縁性の膜が形成されていて、金属ステージに搭載した基板10の下面を介して基板10と基板電極70(80)との間に電圧を印加できない場合であっても、基板接合部70c,80cと基板10とを確実に静電接合させることができる。   As described above, in the semiconductor sensor according to the second embodiment of the present invention, a portion to be the two substrate electrodes 70 and 80 is formed, and a potential difference is given between the electrode pads 71 and 81 to thereby form the substrate. The joining portions 70c and 80c and the substrate 10 are brought into close contact (electrostatic joining). Therefore, an insulating film such as an oxide film or a nitride film is formed on the lower surface of the substrate 10, and a voltage is applied between the substrate 10 and the substrate electrode 70 (80) via the lower surface of the substrate 10 mounted on the metal stage. Even if it cannot apply, the board | substrate junction part 70c, 80c and the board | substrate 10 can be electrostatically joined reliably.

なお、上記においては、基板電極80は、パッド部80a、変形部80b、及び基板接合部80cとから構成されていたが、パッド部80aのみから構成させておくこともできる。この意味において、上記基板電極80は、基板電極70に対する電圧印加用電極として機能する。また、第2実施形態に係る半導体センサの使用態様については第1実施形態と同様である。   In the above description, the substrate electrode 80 includes the pad portion 80a, the deformable portion 80b, and the substrate bonding portion 80c. However, the substrate electrode 80 may include only the pad portion 80a. In this sense, the substrate electrode 80 functions as a voltage application electrode for the substrate electrode 70. The usage mode of the semiconductor sensor according to the second embodiment is the same as that of the first embodiment.

次に、本発明による半導体センサの第3実施形態について図7を参照しながら説明すると、この第3実施形態は、構造に関して基板電極の一部が基板10とは静電接合されていない点において、基板電極70の一部(基板接合部70c)が基板10と静電接合する第1実施形態と異なっている。以下、図6において第1実施形態と同一の部分には図1と同一の参照符号を付し、その詳細説明を省略する。   Next, a third embodiment of the semiconductor sensor according to the present invention will be described with reference to FIG. 7. This third embodiment is different in that a part of the substrate electrode is not electrostatically bonded to the substrate 10 with respect to the structure. This is different from the first embodiment in which a part of the substrate electrode 70 (substrate bonding portion 70c) is electrostatically bonded to the substrate 10. Hereinafter, in FIG. 6, the same parts as those of the first embodiment are denoted by the same reference numerals as those of FIG. 1, and detailed description thereof will be omitted.

この第3実施形態においては、基板電極(基板電極パッド)85が可動部40等とは離れた位置であって、電極パッド13と同一平面内に位置するように、導電性の枠体30の上面に形成されている。基板電極85は、アルミニウム等の導電金属の薄膜であって、方形状にスパッタリング法等により形成され、枠体30と電気的に接続されている。また、基板電極85の上面には図示しない接続導線が接合され、この導線を介して第1,第2実施形態と同様の電気回路装置に接続されている。   In the third embodiment, the conductive frame 30 is arranged such that the substrate electrode (substrate electrode pad) 85 is located away from the movable portion 40 and the like and is located in the same plane as the electrode pad 13. It is formed on the upper surface. The substrate electrode 85 is a thin film of a conductive metal such as aluminum, and is formed in a square shape by a sputtering method or the like and is electrically connected to the frame body 30. Further, a connection conducting wire (not shown) is joined to the upper surface of the substrate electrode 85, and is connected to the same electric circuit device as that in the first and second embodiments via this conducting wire.

枠体30は、犠牲層20を介して基板10との間にコンデンサを構成している。同様に、可動部40もベース部12a〜12dにおいて犠牲層20を介して基板10との間にコンデンサを構成している。また、枠体30は可動部40よりも、極めて大きい面積をもって基板10の上面と対向している。これにより、枠体30と基板10との間の静電容量C1、基板10と可動部40との間の静電容量をC2とすると、C1はC2に対して極めて大きい値(C1はC2を実質的に無視し得る程度の大きさ)となる。なお、可動部40は空間(密度の極めて小さい空気)を介して基板10と対向していて、その部分において基板10との間に静電容量を有するが、空間の誘電率が極めて小さいこと及び面積が小さいことから、その部分の容量は無視し得る。   The frame 30 forms a capacitor between the substrate 30 and the sacrificial layer 20. Similarly, the movable portion 40 also forms a capacitor between the base portions 12a to 12d and the substrate 10 via the sacrificial layer 20. The frame 30 is opposed to the upper surface of the substrate 10 with a much larger area than the movable portion 40. As a result, when the electrostatic capacity C1 between the frame 30 and the substrate 10 and the electrostatic capacity between the substrate 10 and the movable part 40 are C2, C1 is an extremely large value relative to C2 (C1 is C2). The size is substantially negligible). The movable part 40 is opposed to the substrate 10 through a space (air with extremely low density), and has a capacitance between the movable part 40 and the substrate 10 at that portion, but the dielectric constant of the space is extremely small and Since the area is small, the capacity of the part can be ignored.

従って、可動部40と基板電極85との間に電位差V1が生じたと考えた場合、基板電極85と基板間10の電位差V2は、V2=(C2/(C1+C2))×V1となって、C1はC2に比べて極めて大きいので、V2≒0となる。つまり、基板電極85の電位は基板10の電位と等しくなり、基板電極85に基板10の電位が取出されていることとなる。これにより、基板電極85と可動部40とを上記電気回路装置のオペアンプを介して接続すれば、基板10と可動部40とは同電位で、且つその間のインピーダンスが無限大となる。   Accordingly, when it is considered that the potential difference V1 is generated between the movable portion 40 and the substrate electrode 85, the potential difference V2 between the substrate electrode 85 and the substrate 10 is V2 = (C2 / (C1 + C2)) × V1, and C1 Is very large compared to C2, V2≈0. That is, the potential of the substrate electrode 85 becomes equal to the potential of the substrate 10, and the potential of the substrate 10 is taken out to the substrate electrode 85. Thereby, if the board | substrate electrode 85 and the movable part 40 are connected via the operational amplifier of the said electric circuit apparatus, the board | substrate 10 and the movable part 40 will be the same potential, and the impedance between them will become infinite.

以上、説明したように、第3実施形態に係る半導体センサによれば、基板電極85の一部を基板10に接合することなく、基板電極85に基板10の電位を取出すことができるため、基板電極70,80を基板10に静電接合する工程を省略できる。また、基板電極85は絶縁層20の上に設けられているので、容易に接続導線を接合することができる。   As described above, according to the semiconductor sensor according to the third embodiment, the potential of the substrate 10 can be taken out to the substrate electrode 85 without bonding a part of the substrate electrode 85 to the substrate 10. The step of electrostatic bonding the electrodes 70 and 80 to the substrate 10 can be omitted. Further, since the substrate electrode 85 is provided on the insulating layer 20, the connecting conductor can be easily joined.

更に、基板電極85は上記電気回路装置と接続されているため、基板10と可動部40とが同電位とされるとともに、基板10と可動部40との間のインピーダンスは高インピーダンスに維持されるため、振動特性が安定し、検出精度の高い半導体センサとなっている。   Further, since the substrate electrode 85 is connected to the electric circuit device, the substrate 10 and the movable portion 40 are set to the same potential, and the impedance between the substrate 10 and the movable portion 40 is maintained at a high impedance. Therefore, the vibration characteristic is stable and the semiconductor sensor has high detection accuracy.

以上、各実施形態に基づいて説明したように、本発明によれば出力特性が安定し検出精度の高い半導体センサが提供される。なお、本発明は、上記実施形態に限られることはなく、基板上に静電引力等の外力により駆動される振動部を有し、その振動部の変位を静電容量の変化として測定・検出する原理に基づく各種センサ(例えば、角速度センサ、振動型加速度センサ、振動型圧力センサ等)に適用することができる。   As described above, as described based on each embodiment, according to the present invention, a semiconductor sensor with stable output characteristics and high detection accuracy is provided. The present invention is not limited to the above embodiment, and has a vibration part driven by an external force such as electrostatic attraction on a substrate, and the displacement of the vibration part is measured and detected as a change in capacitance. It can be applied to various sensors (for example, an angular velocity sensor, a vibration-type acceleration sensor, a vibration-type pressure sensor, etc.) based on the principle to be performed.

(A)は本発明の第1実施形態の概略平面図であり、(B)は(A)の1−1線に沿った断面図である。(A) is a schematic plan view of 1st Embodiment of this invention, (B) is sectional drawing along the 1-1 line of (A). 図1の1−1線に沿った断面を製造工程別に示した図である。It is the figure which showed the cross section along the 1-1 line | wire of FIG. 1 according to the manufacturing process. 図1の2−2線に沿った断面を製造工程別に示した図である。It is the figure which showed the cross section along the 2-2 line | wire of FIG. 1 according to the manufacturing process. 図1の2−2線に沿った断面を製造工程別に示した図である。It is the figure which showed the cross section along the 2-2 line | wire of FIG. 1 according to the manufacturing process. 図1の半導体センサが接続される電気回路装置の概略図である。It is the schematic of the electric circuit apparatus to which the semiconductor sensor of FIG. 1 is connected. (A)は本発明の第2実施形態の概略平面図であり、(B)は(A)の1−1線に沿った断面図である。(A) is a schematic plan view of 2nd Embodiment of this invention, (B) is sectional drawing along the 1-1 line of (A). (A)は本発明の第3実施形態の概略平面図であり、(B)は(A)の1−1線に沿った断面図である。(A) is a schematic plan view of 3rd Embodiment of this invention, (B) is sectional drawing along the 1-1 line of (A).

符号の説明Explanation of symbols

10…基板、11a〜11d…梁、13,52a,52b,62a,62b…電極パッド、20…犠牲層、30…枠体、40…可動部(振動子)、41a,41b,42a,42b,50a,50b,60a,60b…櫛歯状電極、70…基板電極、70a…パッド部、70b…変形部、70c…基板接合部、71…電極パッド、OP1…オペアンプ、V…検出用高周波電源、Vd…駆動用高周波電源。
DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 11a-11d ... Beam, 13, 52a, 52b, 62a, 62b ... Electrode pad, 20 ... Sacrificial layer, 30 ... Frame, 40 ... Movable part (vibrator), 41a, 41b, 42a, 42b, 50a, 50b, 60a, 60b ... comb-teeth electrode, 70 ... substrate electrode, 70a ... pad portion, 70b ... deformation portion, 70c ... substrate bonding portion, 71 ... electrode pad, OP1 ... operational amplifier, V ... high frequency power source for detection, Vd: Driving high frequency power source.

Claims (4)

基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部と、前記基板に絶縁層を介して支持されるとともに同基板と密着する部分とを有してなり同基板の電位を取り出す基板電極とを備えた半導体センサの製造方法において、
前記基板電極の製造工程が、
前記基板上面の絶縁層に支持され同基板方向に変形可能な前記基板電極となる部材を形成する工程と、
前記基板電極となる部材の一部を前記基板に静電接合させる工程とを含んだことを特徴とする半導体センサの製造方法。
There is a movable part supported on the substrate through an insulating layer so as to be able to vibrate, a detection unit for detecting displacement of the movable part, and a portion supported by the substrate through the insulating layer and in close contact with the substrate. In the manufacturing method of a semiconductor sensor provided with a substrate electrode for taking out the potential of the substrate,
The manufacturing process of the substrate electrode comprises:
Forming a member to be the substrate electrode supported by the insulating layer on the upper surface of the substrate and deformable in the substrate direction;
And a step of electrostatically bonding a part of the member to be the substrate electrode to the substrate.
基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部と、前記基板に絶縁層を介して支持されるとともに同基板と密着する部分とを有してなり同基板の電位を取り出す基板電極とを備えた半導体センサの製造方法において、
前記基板電極の製造工程が、
前記基板上面の絶縁層に支持され同基板方向に変形可能な前記基板電極となる部材を形成する工程と、
前記基板上面の絶縁層の上面に電圧印加用電極を形成する工程と、
前記基板電極となる部材と前記電圧印加用電極との間に電圧を印加して同基板電極となる部材の一部を前記基板に静電接合させる工程とを含んだことを特徴とする半導体センサの製造方法。
A movable part supported on a substrate through an insulating layer so as to be able to vibrate, a detection unit for detecting displacement of the movable part, and a portion supported on the substrate through an insulating layer and in close contact with the substrate. In the manufacturing method of a semiconductor sensor provided with a substrate electrode for taking out the potential of the substrate,
The manufacturing process of the substrate electrode comprises:
Forming a member to be the substrate electrode supported by the insulating layer on the upper surface of the substrate and deformable in the substrate direction;
Forming a voltage applying electrode on the upper surface of the insulating layer on the upper surface of the substrate;
A step of applying a voltage between the member serving as the substrate electrode and the voltage applying electrode to electrostatically bond a part of the member serving as the substrate electrode to the substrate. Manufacturing method.
基板に絶縁層を介して振動可能に支持された可動部と、前記可動部の変位を検出する検出部と、前記基板と前記可動部とを同電位に維持する同電位維持手段と、を備えた半導体センサにおいて、
前記同電位維持手段は、前記基板に絶縁層を介して配設された基板電極を含み、同基板電極の一部が前記基板の上面と静電接合されてなることを特徴とする半導体センサ。
A movable part supported on a substrate through an insulating layer so as to be able to vibrate; a detection part for detecting displacement of the movable part; and a same potential maintaining means for maintaining the substrate and the movable part at the same potential. In semiconductor sensors
The same potential maintaining means includes a substrate electrode disposed on the substrate via an insulating layer, and a part of the substrate electrode is electrostatically bonded to the upper surface of the substrate.
基板に絶縁層を介して支持されるとともに同基板上で互いに直交する振動軸方向及び検出軸方向に振動可能な可動部と、
前記基板に絶縁層を介して配設されるとともに印加される電圧に基づいて前記可動部を前記振動軸方向に振動させる駆動部と、
前記基板に絶縁層を介して配設される検出用電極を含むとともに前記可動部の前記検出軸方向の変位を同可動部と同検出用電極とにより構成されるコンデンサの静電容量の変化として検出する検出部と、
前記基板と前記可動部とを同電位に維持する同電位維持手段と、
を備えた半導体センサにおいて、
前記同電位維持手段は、
前記基板に絶縁層を介して配設された基板電極を含み、同基板電極の一部が同基板の上面と静電接合され、同基板電極と前記可動部とが所定の電気回路装置に接続されることにより、同可動部と同基板との間を同電位に維持するとともに前記駆動部に印加される電圧に起因する電流が同可動部に実質的に流れないように同可動部と同基板との間のインピーダンスを所定の高インピーダンスに維持するように構成されたことを特徴とする半導体センサ。
A movable part supported on the substrate via an insulating layer and capable of vibrating in a vibration axis direction and a detection axis direction orthogonal to each other on the substrate;
A drive unit disposed on the substrate via an insulating layer and configured to vibrate the movable unit in the vibration axis direction based on an applied voltage;
The displacement of the movable part including the detection electrode disposed on the substrate via an insulating layer in the detection axis direction is defined as a change in capacitance of a capacitor formed by the movable part and the detection electrode. A detection unit to detect;
Same potential maintaining means for maintaining the substrate and the movable portion at the same potential;
In a semiconductor sensor equipped with
The same potential maintaining means includes
Including a substrate electrode disposed on the substrate via an insulating layer, a part of the substrate electrode is electrostatically bonded to the upper surface of the substrate, and the substrate electrode and the movable part are connected to a predetermined electric circuit device As a result, the same potential is maintained between the movable portion and the substrate as well as the movable portion so that the current caused by the voltage applied to the driving portion does not substantially flow to the movable portion. A semiconductor sensor configured to maintain an impedance between a substrate and a predetermined high impedance.
JP2003314796A 2003-09-05 2003-09-05 Semiconductor sensor and method for manufacturing the same Expired - Fee Related JP3729192B2 (en)

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JP2007298405A (en) * 2006-04-28 2007-11-15 Matsushita Electric Works Ltd Electrostatic capacity type sensor
JP2009145321A (en) * 2007-11-19 2009-07-02 Hitachi Ltd Inertial sensor

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