JP2005321257A - Capacitance type pressure sensor - Google Patents

Capacitance type pressure sensor Download PDF

Info

Publication number
JP2005321257A
JP2005321257A JP2004138397A JP2004138397A JP2005321257A JP 2005321257 A JP2005321257 A JP 2005321257A JP 2004138397 A JP2004138397 A JP 2004138397A JP 2004138397 A JP2004138397 A JP 2004138397A JP 2005321257 A JP2005321257 A JP 2005321257A
Authority
JP
Japan
Prior art keywords
fixed electrode
gap
pressure sensor
electrode
diaphragm
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2004138397A
Other languages
Japanese (ja)
Inventor
Manabu Tamura
学 田村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alps Alpine Co Ltd
Original Assignee
Alps Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Alps Electric Co Ltd filed Critical Alps Electric Co Ltd
Priority to JP2004138397A priority Critical patent/JP2005321257A/en
Publication of JP2005321257A publication Critical patent/JP2005321257A/en
Pending legal-status Critical Current

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitance type pressure sensor capable of detecting highly accurately a volume change in a wide pressure range from a low pressure to a high pressure. <P>SOLUTION: In this capacitance type pressure sensor, one substrate 2 where a movable electrode 3 comprising a diaphragm deformed elastically by a pressure and the other substrate 5 where a fixed electrode 4 is formed are arranged oppositely through a gap 6 provided between the movable electrode 3 and the fixed electrode 4, and a capacitance change between the movable electrode 3 and the fixed electrode 4 is detected. In the capacitance type pressure sensor 1, the fixed electrode 4 is formed so that the gap 6 at the center part of the fixed electrode 4 becomes narrower than the gap 6 at the peripheral part of the fixed electrode 4, and an insulating film 12 for covering the surface on the gap side of the fixed electrode 4 and/or the movable electrode 3 is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、一方の基板に形成された固定電極部と、他方の基板に形成されたダイヤフラム部との間にギャップが設けられた静電容量型圧力センサに関するものである。   The present invention relates to a capacitance type pressure sensor in which a gap is provided between a fixed electrode portion formed on one substrate and a diaphragm portion formed on the other substrate.

静電容量型圧力センサは、小型でしかも構造が単純であることから、最近になって様々な分野において急速に普及している。
図8に、従来の静電容量型圧力センサを示す。従来の静電容量型圧力センサ101は、図8に示すように、Si基板102の一部を薄くして形成されたダイヤフラム103と、このダイヤフラム103に対向配置された固定電極104と、この固定電極104のダイヤフラム103側表面の一部に形成された凸状絶縁膜112と、固定電極104及びSi基板102を支持する支持基板105とを主体として構成されている。固定電極104及び凸状絶縁膜112と、ダイヤフラム103との間にはギャップ106が設けられており、このギャップ106が誘電体となって一種の静電容量が形成されている(例えば、特許文献1参照)。
Si基板102の上面には電極パッド(図示略)が形成され、この電極パッドにワイヤ(図示略)が接続されており、固定電極104には支持基板105をくぐって形成された取出電極(図示略)が接続されており、この取出電極にワイヤ(図示略)が接続されている。
Capacitance-type pressure sensors are small in size and simple in structure, and have recently become widespread in various fields.
FIG. 8 shows a conventional capacitive pressure sensor. As shown in FIG. 8, a conventional capacitive pressure sensor 101 includes a diaphragm 103 formed by thinning a part of a Si substrate 102, a fixed electrode 104 disposed opposite to the diaphragm 103, and a fixed electrode. The electrode 104 is mainly composed of a convex insulating film 112 formed on a part of the surface on the diaphragm 103 side and a support substrate 105 that supports the fixed electrode 104 and the Si substrate 102. A gap 106 is provided between the fixed electrode 104 and the convex insulating film 112 and the diaphragm 103, and this gap 106 serves as a dielectric to form a kind of capacitance (for example, Patent Documents). 1).
An electrode pad (not shown) is formed on the upper surface of the Si substrate 102, a wire (not shown) is connected to the electrode pad, and an extraction electrode (not shown) formed through the support substrate 105 through the fixed electrode 104. (Not shown) is connected, and a wire (not shown) is connected to the extraction electrode.

この静電容量型圧力センサ101では、流体の圧力変化に対応してダイヤフラム103が弾性変形して撓むことによってギャップの幅が変動し、このギャップ幅の変動を静電容量の変化で捉えて圧力を検知できるようになっているものである。詳しくは、流体の圧力が高くなると、まずダイヤフラム103は撓んで凸状絶縁膜112に接触した状態となる。さらにダイヤフラム103が撓むと、図8の点線Aで示すように絶縁膜112との接触部を支点とし、この支点の両側でそれぞれ撓むことで固定電極104とのギャップ幅が変化して、容量変化が生じる。
特開2002−318166号公報
In this capacitive pressure sensor 101, the width of the gap varies as the diaphragm 103 is elastically deformed and bent in response to a change in the pressure of the fluid, and the variation in the gap width is captured by a change in the capacitance. The pressure can be detected. Specifically, when the fluid pressure increases, the diaphragm 103 first bends and comes into contact with the convex insulating film 112. Further, when the diaphragm 103 is bent, as shown by a dotted line A in FIG. 8, the contact portion with the insulating film 112 is used as a fulcrum, and the gap width with the fixed electrode 104 is changed by bending at both sides of the fulcrum. Change occurs.
JP 2002-318166 A

しかしながら従来の静電容量型圧力センサにおいては、高圧力側ではダイヤフラム103が絶縁膜112との接触部の両側でそれぞれ撓んで固定電極104とのギャップが狭くなるため圧力に対する容量変化(感度)が大きいが、低圧力側ではダイヤフラム103と固定電極104の距離が遠い(例えば、ダイヤフラム103が絶縁膜112に接触しているだけの状態)ために、圧力に対する容量変化(感度)が小さいという問題があった。   However, in the conventional capacitive pressure sensor, on the high pressure side, the diaphragm 103 bends on both sides of the contact portion with the insulating film 112 and the gap with the fixed electrode 104 is narrowed. Although large, on the low pressure side, the distance between the diaphragm 103 and the fixed electrode 104 is long (for example, the state in which the diaphragm 103 is only in contact with the insulating film 112), so that there is a problem that the capacitance change (sensitivity) with respect to pressure is small. there were.

本発明は上記事情に鑑みてなされたもので、低圧から高圧までの広い圧力範囲にわたって容量変化を高感度で検出できる静電容量型圧力センサの提供を目的とする。   The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a capacitive pressure sensor that can detect a change in capacitance with high sensitivity over a wide pressure range from low pressure to high pressure.

本発明の静電容量型圧力センサは、圧力によって弾性変形するダイヤフラムからなる可動電極が形成された一方の基板と、固定電極が形成された他方の基板とが上記可動電極と固定電極の間に設けられたギャップを介して対向配置され、上記可動電極と固定電極との間の静電容量の変化を検出する静電容量型圧力センサであって、
上記固定電極は、該固定電極の中心部における上記ギャップが、上記固定電極の周縁部における上記ギャップより狭くなるような形状とされ、
上記固定電極及び/又は可動電極のギャップ側の表面を覆う絶縁膜が形成されたことを特徴とする。
The capacitance-type pressure sensor of the present invention includes a substrate on which a movable electrode made of a diaphragm that is elastically deformed by pressure and a substrate on which a fixed electrode is formed between the movable electrode and the fixed electrode. A capacitance type pressure sensor that is arranged to face each other through a provided gap and detects a change in capacitance between the movable electrode and the fixed electrode,
The fixed electrode is shaped such that the gap at the center of the fixed electrode is narrower than the gap at the periphery of the fixed electrode,
An insulating film is formed to cover the gap side surface of the fixed electrode and / or the movable electrode.

本発明の静電容量型圧力センサでは、上記固定電極の中心部と上記可動電極間のギャップが、上記固定電極の周縁部と上記可動電極間のギャップより狭くされたことにより、低圧側で圧力が変化した場合はギャップが狭いところで可動電極と固定電極のギャップ幅が変化することとなり、低圧力側での容量変化を高感度で検出できる。また、圧力がさらに高くなると、上記固定電極の中心部と上記可動電極とが接触両側で固定電極と可動電極間のギャップ幅が変化するため、高圧力側の容量変化を高感度で検出できる。従って、本発明の静電容量型圧力センサでは、低圧から高圧までの広い圧力範囲にわたって容量変化を高感度で検出することができる。   In the capacitance type pressure sensor of the present invention, the gap between the center portion of the fixed electrode and the movable electrode is narrower than the gap between the peripheral portion of the fixed electrode and the movable electrode. When the gap changes, the gap width between the movable electrode and the fixed electrode changes when the gap is narrow, and the capacitance change on the low pressure side can be detected with high sensitivity. Further, when the pressure is further increased, the gap width between the fixed electrode and the movable electrode changes on both sides of contact between the central portion of the fixed electrode and the movable electrode, so that the capacitance change on the high pressure side can be detected with high sensitivity. Therefore, the capacitance type pressure sensor of the present invention can detect a change in capacitance with high sensitivity over a wide pressure range from low pressure to high pressure.

また、上記構成の本発明の静電容量型圧力センサにおいて、上記ギャップの縦断面は、上記固定電極の周縁部から中心部にかけて階段状に狭くなる形状であってもよい。   In the capacitive pressure sensor of the present invention having the above-described configuration, the vertical cross section of the gap may have a stepwise narrowing shape from the periphery to the center of the fixed electrode.

また、上記いずれかの構成の本発明の静電容量型圧力センサにおいて、上記固定電極の形状が凸字状であることが製造し易い点で好ましい。   Moreover, in the capacitance type pressure sensor of the present invention having any one of the above structures, the shape of the fixed electrode is preferably a convex shape because it is easy to manufacture.

本発明によれば、低圧から高圧までの広い圧力範囲にわたって容量変化を高感度で検出できる静電容量型圧力センサを提供できる。   According to the present invention, it is possible to provide a capacitive pressure sensor that can detect a change in capacitance with high sensitivity over a wide pressure range from low pressure to high pressure.

次に図面を用いて本発明の実施の形態を詳細に説明する。
なお、本発明は以下に説明する実施の形態に限定されるものではないことは勿論であるとともに、以下の図面においては各構成部分の縮尺について図面に表記することが容易となるように構成部分毎に縮尺を変えて記載している。
Next, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention is of course not limited to the embodiments described below, and in the following drawings, the constituent parts are shown so that the scale of each constituent part can be easily shown in the drawings. The scale is changed every time.

図1は、本発明の実施形態の静電容量型圧力センサの概略構成を示す断面図である。
本実施形態の静電容量型圧力センサ1は、シリコン基板(一方の基板)2の一部を薄くして形成された可動電極としてのダイヤフラム3と、このダイヤフラム3に対向配置された固定電極4と、固定電極4及びシリコン基板2を支持する支持基板(他方の基板)5とを主体として構成されている。
ダイヤフラム3と固定電極4との間にはギャップ6が設けられており、このギャップ6が誘電体となって一種の静電容量が形成されている。
支持基板5のシリコン基板2側の表面には、固定電極4を覆うように絶縁膜12が形成されている。従って、この固定電極4のギャップ側の表面は絶縁膜12が形成されている。絶縁膜12の材質は、シリコン酸化膜や、シリコン窒化膜などが用いられ、また、厚みは0.05μm〜0.2μm程度とされる。
この静電容量型圧力センサ1は、流体の圧力変化に対応してダイヤフラム3が弾性変形して撓むことによってギャップ幅が変動し、このギャップ幅の変動を静電容量の変化で捉えて圧力を検知できるものである。
FIG. 1 is a cross-sectional view showing a schematic configuration of a capacitive pressure sensor according to an embodiment of the present invention.
A capacitive pressure sensor 1 according to this embodiment includes a diaphragm 3 as a movable electrode formed by thinning a part of a silicon substrate (one substrate) 2, and a fixed electrode 4 arranged to face the diaphragm 3. And a support substrate (the other substrate) 5 that supports the fixed electrode 4 and the silicon substrate 2.
A gap 6 is provided between the diaphragm 3 and the fixed electrode 4, and this gap 6 serves as a dielectric to form a kind of electrostatic capacity.
An insulating film 12 is formed on the surface of the support substrate 5 on the silicon substrate 2 side so as to cover the fixed electrode 4. Therefore, the insulating film 12 is formed on the surface of the fixed electrode 4 on the gap side. The insulating film 12 is made of a silicon oxide film, a silicon nitride film, or the like, and has a thickness of about 0.05 μm to 0.2 μm.
In this capacitive pressure sensor 1, the gap width changes due to the elastic deformation of the diaphragm 3 corresponding to a change in the pressure of the fluid, and the change in the gap width is detected by the change in the capacitance. Can be detected.

固定電極4は、該固定電極4の中心部とダイヤフラム3間のギャップ6が、固定電極4の周縁部とダイヤフラム3間のギャップ6より狭くなるような形状とされている。
固定電極4は縦断面階段状とされ、特に、本実施形態では縦断面形状が凸字とされている。
固定電極4は、第1の導電性金属膜4aと、この第1の導電性金属膜4aの中央部に積層された第2の導電性金属膜4bから構成されることで、固定電極4の中央部に第2の導電性金属膜4bからなる凸部が設けられている。この凸部4bの頂部は、平坦面を有していることが好ましい。
第1の導電性金属膜4aの直径はダイヤフラム3の直径の60〜90%程度とされ、第2の導電性金属膜4bの直径はダイヤフラム3の直径の5〜20%程度とされることが好ましい。
第1の導電性金属膜4aは、Ti、Cr、Pt、W、Al合金などから構成されており、第2の導電性金属膜4bはAl、Cr、Ti、Ptなどから構成されている。第1と第の導電性金属膜4a、4bに用いる材料は、異なる材料を用いるのが、固定電極を形成する際に異なるエッチング液を用いることにより縦断面階段状に成形し易い点で好ましい。
上記のように固定電極4は縦断面階段状とされていることで、静電容量型圧力センサに流体の圧力変化がかかっていない状態のときは、上記ギャップ6の縦断面は、固定電極4の周縁部から中心部にかけて階段状に狭くなる形状となっている。
The fixed electrode 4 is shaped such that the gap 6 between the center of the fixed electrode 4 and the diaphragm 3 is narrower than the gap 6 between the peripheral edge of the fixed electrode 4 and the diaphragm 3.
The fixed electrode 4 has a vertical cross-sectional step shape, and in particular, the vertical cross-sectional shape is convex in this embodiment.
The fixed electrode 4 includes the first conductive metal film 4a and the second conductive metal film 4b laminated at the center of the first conductive metal film 4a. A convex portion made of the second conductive metal film 4b is provided in the central portion. It is preferable that the top part of this convex part 4b has a flat surface.
The diameter of the first conductive metal film 4a may be about 60 to 90% of the diameter of the diaphragm 3, and the diameter of the second conductive metal film 4b may be about 5 to 20% of the diameter of the diaphragm 3. preferable.
The first conductive metal film 4a is made of Ti, Cr, Pt, W, Al alloy or the like, and the second conductive metal film 4b is made of Al, Cr, Ti, Pt or the like. It is preferable to use different materials for the first and the first conductive metal films 4a and 4b because different etching liquids are used when forming the fixed electrodes, so that the first and second conductive metal films 4a and 4b can be easily formed into a stepped vertical section.
As described above, the fixed electrode 4 has a stepwise vertical cross section. When the capacitance pressure sensor is not subjected to a change in fluid pressure, the vertical cross section of the gap 6 is It becomes the shape which becomes narrow in a step shape from the peripheral part to the center part.

シリコン基板2の上面で、ダイヤフラム3が形成されていない部分には電極パッド(図示略)が形成されている。
支持基板5は、例えば、パイレックス(登録商標)などの耐熱ガラスから構成されている。
シリコン基板2に形成された電極パッドにワイヤ(図示略)が接続され、また、固定電極4には支持基板5をくぐって形成された取出電極(図示略)が接続され、この取出電極にワイヤ(図示略)が接続されている。
An electrode pad (not shown) is formed on the upper surface of the silicon substrate 2 where the diaphragm 3 is not formed.
The support substrate 5 is made of heat resistant glass such as Pyrex (registered trademark).
A wire (not shown) is connected to an electrode pad formed on the silicon substrate 2, and an extraction electrode (not shown) formed through the support substrate 5 is connected to the fixed electrode 4, and a wire is connected to the extraction electrode. (Not shown) is connected.

次に、本実施形態の静電容量型圧力センサ1の製造方法について説明する。
本実施形態の静電容量型圧力センサ1の製造方法は、支持基板形成工程(他方の基板形成工程)と、絶縁膜形成工程と、シリコン基板形成工程(一方の基板形成工程)と、両基板接合工程とを具備して構成されている。
Next, a manufacturing method of the capacitive pressure sensor 1 of the present embodiment will be described.
The manufacturing method of the capacitive pressure sensor 1 of this embodiment includes a supporting substrate forming step (the other substrate forming step), an insulating film forming step, a silicon substrate forming step (one substrate forming step), and both substrates. And a joining step.

(支持基板形成工程)
まず、図3のAに示すようにパイレックス(登録商標)からなる支持基板5の表面に第1の導電性金属膜4aを形成し、さらにこの上に第2の導電性金属膜4bを形成する。
次いで、図3のBに示すように、第2の導電性金属膜4b上にマスク材(図示略)を配置し、ウエット又はドライエッチングによりすることにより、中央部のみ第2の導電性金属膜4bを残す。
次いで、図3のCに示すように、第1の導電性金属膜4a上にマスク材(図示略)を配置し、ウエット又はドライエッチングすることにより、縦断面階段状の固定電極4を形成する。
ここでの工程では例えば第1の導電性金属膜4aをTiから構成した場合にはエッチャントとしてフッ酸を用い、第2の導電性金属膜4bをAlから構成した場合には、エッチャントとしてリン酸を用いる。
(Support substrate formation process)
First, as shown in FIG. 3A, a first conductive metal film 4a is formed on the surface of a support substrate 5 made of Pyrex (registered trademark), and a second conductive metal film 4b is further formed thereon. .
Next, as shown in FIG. 3B, a mask material (not shown) is disposed on the second conductive metal film 4b, and wet or dry etching is performed, so that the second conductive metal film only in the central portion. Leave 4b.
Next, as shown in FIG. 3C, a mask material (not shown) is disposed on the first conductive metal film 4a, and wet or dry etching is performed to form a fixed electrode 4 having a stepped vertical section. .
In this step, for example, when the first conductive metal film 4a is made of Ti, hydrofluoric acid is used as an etchant, and when the second conductive metal film 4b is made of Al, phosphoric acid is used as an etchant. Is used.

(絶縁膜形成工程)
図4に示すように支持基板5の表面及び固定電極4の表面に絶縁膜12を形成する。なお、この後、絶縁膜12を固定電極4上及び固定電極4の周辺部のみ残すようにエッチングを行ってもよい。
(シリコン基板形成工程)
まず、図5に示すようにシリコン基板2の下面側(一方の面側)にギャップを形成するための凹部21をエッチングにより形成した後、これの両面にSiO膜又はSi膜からなるマスク材(図示略)を形成し、シリコン基板2の上側(ギャップが形成される側と反対側)のSiO膜又はSi膜にダイヤフラム3を形成するための開口部(図示略)を形成し、この開口部内のシリコン基板を上記SiO膜又はSi膜をマスク材として用いる異方性エッチングにより所定の深さまでエッチングして厚みを薄くして、ダイヤフラム3を形成する。
(Insulating film formation process)
As shown in FIG. 4, an insulating film 12 is formed on the surface of the support substrate 5 and the surface of the fixed electrode 4. Thereafter, the insulating film 12 may be etched so as to leave only the periphery of the fixed electrode 4 and the fixed electrode 4.
(Silicon substrate formation process)
First, as shown in FIG. 5, a recess 21 for forming a gap is formed on the lower surface side (one surface side) of the silicon substrate 2 by etching, and then a SiO 2 film or a Si 3 N 4 film is formed on both surfaces thereof. And an opening (not shown) for forming the diaphragm 3 in the SiO 2 film or Si 3 N 4 film on the upper side of the silicon substrate 2 (opposite side where the gap is formed). And the silicon substrate in the opening is etched to a predetermined depth by anisotropic etching using the SiO 2 film or the Si 3 N 4 film as a mask material to form a diaphragm 3. .

(両基板接合工程)
図4の絶縁膜形成工程で絶縁膜12を形成した支持基板5と、図5のシリコン基板形成工程で凹部21及び可動電極となるダイヤフラム3を形成したシリコン基板2をダイヤフラム3がギャップ6を介して固定電極4と対向するように重ねて陽極接合すると、図1に示すような静電容量型圧力センサ1が得られる。
(Both substrate bonding process)
The support substrate 5 on which the insulating film 12 is formed in the insulating film forming step of FIG. 4 and the silicon substrate 2 on which the concave portion 21 and the diaphragm 3 to be the movable electrode are formed in the silicon substrate forming step of FIG. When the anodic bonding is performed so as to face the fixed electrode 4, a capacitive pressure sensor 1 as shown in FIG. 1 is obtained.

本実施形態の静電容量型圧力センサ1は、固定電極4の中央部に第2の導電性金属膜4bからなる凸部が設けられているので、固定電極4の中心部とダイヤフラム3間のギャップ6が、固定電極4の周縁部とダイヤフラム3間のギャップ6より狭くされているので、低圧側で圧力が変化した場合は図1の点線Bで示すようにダイヤフラム3は撓んで固定電極4の中心部のギャップ幅が変化することで容量が変化するため、低圧力側での容量変化を高感度で検出できる。
圧力がさらに高くなると、図2に示すように固定電極4の中心部とダイヤフラム3との接触両側でもそれぞれ固定電極4とダイヤフラム3のギャップ幅が変化することで容量が変化するため、高圧力側の容量変化を高感度で検出できる。
In the capacitive pressure sensor 1 of the present embodiment, the convex portion made of the second conductive metal film 4 b is provided in the central portion of the fixed electrode 4, and therefore, between the central portion of the fixed electrode 4 and the diaphragm 3. Since the gap 6 is narrower than the gap 6 between the peripheral edge of the fixed electrode 4 and the diaphragm 3, when the pressure changes on the low pressure side, the diaphragm 3 bends as shown by the dotted line B in FIG. Since the capacity changes due to the change in the gap width at the center, the capacity change on the low pressure side can be detected with high sensitivity.
When the pressure is further increased, the capacitance is changed by changing the gap width between the fixed electrode 4 and the diaphragm 3 on both sides of contact between the center portion of the fixed electrode 4 and the diaphragm 3, as shown in FIG. It is possible to detect a change in capacitance with high sensitivity.

なお、上記実施形態の静電容量型圧力センサにおいては、固定電極4の中央部に凸部4bを設けることで縦断面形状が階段状とされた場合について説明したが、本発明の静電容量型圧力センサでは、固定電極の中心部とダイヤフラム間のギャップが、上記固定電極の周縁部と上記ダイヤフラム間のギャップより狭くなっていればよいので、固定電極は図6に示すような形状であってもよい。図6の固定電極34は縦断面形状が弓形とされていることで、固定電極34の中心部とダイヤフラム3間のギャップが、上記固定電極34の周縁部と上記ダイヤフラム3間のギャップより狭くなっている。この固定電極34の表面にも絶縁膜12が形成されている。
また、上記実施形態においては、固定電極4のギャップ側の表面を覆うように絶縁膜12が形成された場合について説明したが、この絶縁膜12はダイヤフラム3のギャップ側の表面に形成されていてもよいし、固定電極4のギャップ側の表面とダイヤフラム3のギャップ側の表面の両方に形成されていてもよい。
In the capacitance type pressure sensor of the above embodiment, the case where the vertical cross-sectional shape is stepped by providing the convex portion 4b at the center of the fixed electrode 4 has been described. In the type pressure sensor, the gap between the center of the fixed electrode and the diaphragm only needs to be narrower than the gap between the peripheral edge of the fixed electrode and the diaphragm, so the fixed electrode has a shape as shown in FIG. May be. The fixed electrode 34 shown in FIG. 6 has an arcuate vertical cross-sectional shape so that the gap between the center of the fixed electrode 34 and the diaphragm 3 is narrower than the gap between the peripheral edge of the fixed electrode 34 and the diaphragm 3. ing. The insulating film 12 is also formed on the surface of the fixed electrode 34.
In the above embodiment, the case where the insulating film 12 is formed so as to cover the gap side surface of the fixed electrode 4 has been described. However, the insulating film 12 is formed on the gap side surface of the diaphragm 3. Alternatively, it may be formed on both the gap side surface of the fixed electrode 4 and the gap side surface of the diaphragm 3.

(実施例1)
パイレックス(登録商標)からなる支持基板に、厚さ0.2μm、径1000μmの第1の導電性金属膜とこれの中央部に設けた厚さ0.2μm、径100μmの第2の導電性金属膜からなる縦断面階段状の固定電極を形成し、この支持基板の表面に固定電極を覆うように厚さ0.05μmのシリコン酸化膜からなる絶縁膜を形成した。
次にシリコン基板に直径1200μm、厚さ50μmのダイヤフラムと、ギャップ用の凹部を形成した。
ついで、上記絶縁膜を形成した支持基板と、上記凹部及びダイヤフラムを形成したシリコン基板をダイヤフラムがギャップを介して固定電極と対向するように重ねて陽極接合し、図1と同様の静電容量型圧力センサを作製し、実施例1とした。
実施例1の静電容量型圧力センサのギャップ幅(支持基板表面からダイヤフラムまでの距離)は、0.8μmであった。また、固定電極の中心部とダイヤフラム間のギャップ幅は0.4μm、固定電極の周縁部とダイヤフラム間のギャップ幅は0.6μmであった。
(Example 1)
A first conductive metal film having a thickness of 0.2 μm and a diameter of 1000 μm and a second conductive metal having a thickness of 0.2 μm and a diameter of 100 μm provided in the center of the support substrate made of Pyrex (registered trademark) A fixed electrode having a stepwise vertical section made of a film was formed, and an insulating film made of a silicon oxide film having a thickness of 0.05 μm was formed on the surface of the support substrate so as to cover the fixed electrode.
Next, a diaphragm having a diameter of 1200 μm and a thickness of 50 μm and a recess for a gap were formed on the silicon substrate.
Next, the support substrate on which the insulating film is formed and the silicon substrate on which the concave portion and the diaphragm are formed are overlapped and anodically bonded so that the diaphragm faces the fixed electrode through a gap, and the capacitance type similar to FIG. A pressure sensor was produced and used as Example 1.
The gap width (distance from the support substrate surface to the diaphragm) of the capacitive pressure sensor of Example 1 was 0.8 μm. The gap width between the center of the fixed electrode and the diaphragm was 0.4 μm, and the gap width between the peripheral edge of the fixed electrode and the diaphragm was 0.6 μm.

(比較例1)
パイレックス(登録商標)からなる支持基板に、厚さ0.2μm、径1000μmの固定電極を形成し、この固定電極の中央部に高さ0.2μm、底面の径100μmの円錐状絶縁膜(凸状絶縁膜)を形成した。
次にシリコン基板に直径1200μm、厚さ50μmのダイヤフラムと、ギャップ用の凹部を形成した。
ついで、上記凸状絶縁膜を形成した支持基板と、上記凹部及びダイヤフラムを形成したシリコン基板をダイヤフラムがギャップを介して固定電極と対向するように重ねて陽極接合し、図8と同様の従来タイプの静電容量型圧力センサを作製し、比較例1とした。
比較例1の静電容量型圧力センサのギャップ幅(支持基板表面からダイヤフラムまでの距離)は、0.8μmであった。また、凸状絶縁膜とダイヤフラム間のギャップ幅は0.4μm、固定電極の周縁部とダイヤフラム間のギャップ幅は0.6μmであった。
(Comparative Example 1)
A fixed electrode having a thickness of 0.2 μm and a diameter of 1000 μm is formed on a support substrate made of Pyrex (registered trademark). The insulating film was formed.
Next, a diaphragm having a diameter of 1200 μm and a thickness of 50 μm and a recess for a gap were formed on the silicon substrate.
Next, the support substrate on which the convex insulating film is formed and the silicon substrate on which the concave portion and the diaphragm are formed are overlapped and anodically bonded so that the diaphragm faces the fixed electrode through a gap, and the conventional type similar to FIG. A capacitance type pressure sensor was manufactured as Comparative Example 1.
The gap width (distance from the support substrate surface to the diaphragm) of the capacitive pressure sensor of Comparative Example 1 was 0.8 μm. The gap width between the convex insulating film and the diaphragm was 0.4 μm, and the gap width between the peripheral edge of the fixed electrode and the diaphragm was 0.6 μm.

図7に作製した実施例1と比較例1の静電容量型圧力センサにそれぞれ0kPa〜600kPaの圧力をかけたときの圧力(kPa)と容量(pF)の関係を示す。
図7に示す結果から実施例1の静電容量型圧力センサは、圧力が同じ値であっても比較例1の静電容量型圧力センサよりも容量変化が大きく、感度が優れており、このような傾向は低圧側でも高力側でも得られていることがわかる。
FIG. 7 shows the relationship between the pressure (kPa) and the capacitance (pF) when a pressure of 0 kPa to 600 kPa is applied to the capacitive pressure sensors of Example 1 and Comparative Example 1 produced.
From the results shown in FIG. 7, the capacitance type pressure sensor of Example 1 has a larger capacitance change and higher sensitivity than the capacitance type pressure sensor of Comparative Example 1, even if the pressure is the same value. It can be seen that such a tendency is obtained on both the low pressure side and the high strength side.

本発明の実施形態の静電容量型圧力センサの概略構成を示す断面図。Sectional drawing which shows schematic structure of the capacitance-type pressure sensor of embodiment of this invention. 図1の静電容量型圧力センサの動作を説明するための断面図。Sectional drawing for demonstrating operation | movement of the electrostatic capacitance type pressure sensor of FIG. 本実施形態の静電容量型圧力センサを製造するための支持基板形成工程の説明図。Explanatory drawing of the support substrate formation process for manufacturing the electrostatic capacitance type pressure sensor of this embodiment. 本実施形態の静電容量型圧力センサを製造するための絶縁膜形成工程の説明図。Explanatory drawing of the insulating film formation process for manufacturing the electrostatic capacitance type pressure sensor of this embodiment. 本実施形態の静電容量型圧力センサを製造するためのシリコン基板形成工程の説明図。Explanatory drawing of the silicon substrate formation process for manufacturing the electrostatic capacitance type pressure sensor of this embodiment. 本発明の他の実施形態の静電容量型圧力センサの概略構成を示す断面図。Sectional drawing which shows schematic structure of the capacitive pressure sensor of other embodiment of this invention. 実施例1と比較例1の静電容量型圧力センサについて圧力と容量の関係を示すグラフ。The graph which shows the relationship between a pressure and a capacity | capacitance about the capacitance-type pressure sensor of Example 1 and Comparative Example 1. 従来の静電容量型圧力センサの例を示す断面図。Sectional drawing which shows the example of the conventional electrostatic capacitance type pressure sensor.

符号の説明Explanation of symbols

1・・・静電容量型圧力センサ、2・・・シリコン基板(一方の基板)、3・・・ダイヤフラム(可動電極)、4,34・・・固定電極、4a・・・第1の導電性金属膜、4b・・・第2の導電性金属膜、5・・・支持基板(他方の基板)、6・・・ギャップ、12・・・絶縁膜   DESCRIPTION OF SYMBOLS 1 ... Capacitance type pressure sensor, 2 ... Silicon substrate (one board | substrate), 3 ... Diaphragm (movable electrode), 4, 34 ... Fixed electrode, 4a ... 1st electroconductivity Conductive metal film, 4b ... second conductive metal film, 5 ... support substrate (the other substrate), 6 ... gap, 12 ... insulating film

Claims (3)

圧力によって弾性変形するダイヤフラムからなる可動電極が形成された一方の基板と、固定電極が形成された他方の基板とが前記可動電極と固定電極の間に設けられたギャップを介して対向配置され、前記可動電極と固定電極との間の静電容量の変化を検出する静電容量型圧力センサであって、
前記固定電極は、該固定電極の中心部における前記ギャップが、前記固定電極の周縁部における前記ギャップより狭くなるような形状とされ、
前記固定電極及び/又は前記可動電極のギャップ側の表面を覆う絶縁膜が形成されたことを特徴とする静電容量型圧力センサ。
One substrate on which a movable electrode made of a diaphragm that is elastically deformed by pressure and the other substrate on which a fixed electrode is formed are arranged to face each other via a gap provided between the movable electrode and the fixed electrode, A capacitance type pressure sensor for detecting a change in capacitance between the movable electrode and the fixed electrode,
The fixed electrode is shaped such that the gap at the center of the fixed electrode is narrower than the gap at the periphery of the fixed electrode,
A capacitance type pressure sensor, wherein an insulating film is formed to cover a surface of the fixed electrode and / or the movable electrode on the gap side.
前記ギャップの縦断面は、前記固定電極の周縁部から中心部にかけて階段状に狭くなる形状であることを特徴とする請求項1記載の静電容量型圧力センサ。   The capacitive pressure sensor according to claim 1, wherein a vertical cross section of the gap has a shape that narrows in a stepped manner from a peripheral portion to a central portion of the fixed electrode. 前記固定電極の形状が凸字状であることを特徴とする請求項2に記載の静電容量型圧力センサ。   The capacitive pressure sensor according to claim 2, wherein the fixed electrode has a convex shape.
JP2004138397A 2004-05-07 2004-05-07 Capacitance type pressure sensor Pending JP2005321257A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004138397A JP2005321257A (en) 2004-05-07 2004-05-07 Capacitance type pressure sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004138397A JP2005321257A (en) 2004-05-07 2004-05-07 Capacitance type pressure sensor

Publications (1)

Publication Number Publication Date
JP2005321257A true JP2005321257A (en) 2005-11-17

Family

ID=35468666

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2004138397A Pending JP2005321257A (en) 2004-05-07 2004-05-07 Capacitance type pressure sensor

Country Status (1)

Country Link
JP (1) JP2005321257A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007303922A (en) * 2006-05-10 2007-11-22 Alps Electric Co Ltd Capacitive pressure sensor
JP2008513800A (en) * 2004-09-23 2008-05-01 ヴェーテーイー テクノロジーズ オサケユキチュア Capacitive sensor and method for manufacturing the capacitive sensor
US20110040189A1 (en) * 2007-12-14 2011-02-17 Koninklijke Philips Electronics N.V. Collapsed mode operable cmut including contoured substrate
KR101181509B1 (en) 2010-04-30 2012-09-10 (주)코아칩스 Back touch type capacitive pressure sensor
WO2013073506A1 (en) * 2011-11-14 2013-05-23 オムロン株式会社 Capacitance type pressure sensor, method for manufacturing same, and input device
US20150090029A1 (en) * 2013-09-30 2015-04-02 Seiko Epson Corporation Physical quantity sensor, pressure sensor, altimeter, electronic apparatus, and moving object
KR101818315B1 (en) * 2013-03-11 2018-01-12 오므론 가부시키가이샤 Capacitive pressure sensor and input device
CN109074186A (en) * 2016-04-08 2018-12-21 希迪普公司 Constitute multiple channels pressure sensor, containing its touch input device and utilize its pressure detection method
JP2019158716A (en) * 2018-03-15 2019-09-19 オムロン株式会社 Capacitive pressure sensor

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008513800A (en) * 2004-09-23 2008-05-01 ヴェーテーイー テクノロジーズ オサケユキチュア Capacitive sensor and method for manufacturing the capacitive sensor
JP2007303922A (en) * 2006-05-10 2007-11-22 Alps Electric Co Ltd Capacitive pressure sensor
US20110040189A1 (en) * 2007-12-14 2011-02-17 Koninklijke Philips Electronics N.V. Collapsed mode operable cmut including contoured substrate
JP2011506075A (en) * 2007-12-14 2011-03-03 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ CMUT operable in collapse mode with contoured substrate
US8787116B2 (en) 2007-12-14 2014-07-22 Koninklijke Philips N.V. Collapsed mode operable cMUT including contoured substrate
KR101181509B1 (en) 2010-04-30 2012-09-10 (주)코아칩스 Back touch type capacitive pressure sensor
JP2013104797A (en) * 2011-11-14 2013-05-30 Omron Corp Capacitance type pressure sensor and manufacturing method thereof, and input device
CN103765179A (en) * 2011-11-14 2014-04-30 欧姆龙株式会社 Capacitance type pressure sensor, method for manufacturing same, and input device
WO2013073506A1 (en) * 2011-11-14 2013-05-23 オムロン株式会社 Capacitance type pressure sensor, method for manufacturing same, and input device
KR101818315B1 (en) * 2013-03-11 2018-01-12 오므론 가부시키가이샤 Capacitive pressure sensor and input device
US20150090029A1 (en) * 2013-09-30 2015-04-02 Seiko Epson Corporation Physical quantity sensor, pressure sensor, altimeter, electronic apparatus, and moving object
CN109074186A (en) * 2016-04-08 2018-12-21 希迪普公司 Constitute multiple channels pressure sensor, containing its touch input device and utilize its pressure detection method
JP2019158716A (en) * 2018-03-15 2019-09-19 オムロン株式会社 Capacitive pressure sensor

Similar Documents

Publication Publication Date Title
JP2005321257A (en) Capacitance type pressure sensor
JP5737148B2 (en) Capacitive pressure sensor, method for manufacturing the same, and input device
JP3114570B2 (en) Capacitive pressure sensor
JP2010203818A (en) Semiconductor sensor and method of manufacturing the same
EP1898196A2 (en) Method for fabricating capacitive pressure sensor and capacitive pressure sensor fabricated thereby
JP2005195423A (en) Pressure sensor
WO2019019783A1 (en) Wide-range high-precision double-film-integrated capacitive pressure sensor and preparation method therefor
WO2019019843A1 (en) Double-film capacitive pressure sensor and manufacturing method
JP2006047279A (en) Glass substrate, and capacitance-type pressure sensor using the same
TW201323845A (en) MEMS pressure sensor device and manufacturing method thereof
JP2007101222A (en) Pressure sensor
CN103983395A (en) Micro-pressure sensor and manufacturing and detecting method thereof
JP2007225344A (en) Pressure sensor
JP4549085B2 (en) Capacitance type pressure sensor and manufacturing method thereof
JP5695741B2 (en) Capacitance type pressure sensor and manufacturing method thereof
EP1788372A2 (en) Capacitive pressure sensor
JP2006126127A (en) Capacitance type pressure sensor
JP2006200980A (en) Capacitance type pressure sensor and capacitance type actuator
JP2006208135A (en) Pressure sensor and its manufacturing method
JP2008032451A (en) Variable capacitance pressure sensor
WO2015025496A1 (en) Semiconductor physical quantity sensor
JP2005010149A (en) Capacity-type dynamic amount sensor, and manufacturing method therefor
JP2005300400A (en) Capacitance-type pressure sensor and its manufacturing method
JP2005083801A (en) Pressure sensor
JP2007093234A (en) Pressure sensor

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060913

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A821

Effective date: 20060914

A977 Report on retrieval

Effective date: 20090107

Free format text: JAPANESE INTERMEDIATE CODE: A971007

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20090120

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20090312

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20090407