JPH0420131B2 - - Google Patents
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- Publication number
- JPH0420131B2 JPH0420131B2 JP13694283A JP13694283A JPH0420131B2 JP H0420131 B2 JPH0420131 B2 JP H0420131B2 JP 13694283 A JP13694283 A JP 13694283A JP 13694283 A JP13694283 A JP 13694283A JP H0420131 B2 JPH0420131 B2 JP H0420131B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- movable electrode
- layer
- movable
- epitaxial growth
- 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.)
- Expired
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0041—Transmitting or indicating the displacement of flexible diaphragms
- G01L9/0072—Transmitting or indicating the displacement of flexible diaphragms using variations in capacitance
- G01L9/0073—Transmitting or indicating the displacement of flexible diaphragms using variations in capacitance using a semiconductive diaphragm
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
- Pressure Sensors (AREA)
Description
【発明の詳細な説明】
本発明は、圧力、差圧等の被測定量に応じて固
定電極に対する移動電極が変位し、この変位によ
り電極間の静電容量が変化するのを検出して圧力
等を検出する半導体容量形圧力センサに関するも
のである。Detailed Description of the Invention The present invention displaces a movable electrode with respect to a fixed electrode in accordance with a measured quantity such as pressure or differential pressure, and detects the change in capacitance between the electrodes due to this displacement. The present invention relates to a semiconductor capacitive pressure sensor that detects
容量形圧力センサにおいては、小型化をはかる
と感圧容量の絶対値が、たとえば、５〜15PFと
小さくなる。この場合、センサ部分に発生する浮
遊容量の影響が問題となり、通常においては、感
圧容量より大きくなつてしまう。 In a capacitive pressure sensor, when miniaturization is attempted, the absolute value of the pressure-sensitive capacitance becomes small, for example, 5 to 15 PF. In this case, the influence of stray capacitance generated in the sensor portion poses a problem, which is normally larger than the pressure-sensitive capacitance.
これ等の浮遊容量は、温度誤差、直線性の劣下
となつて特性に悪影響を及ぼす。 These stray capacitances adversely affect the characteristics by causing temperature errors and deterioration of linearity.
第１図、第２図は、従来より一般に使用されて
いる従来例の構成説明図で、第１図は平面図、第
２図は側断面図である。 FIGS. 1 and 2 are explanatory diagrams of the configuration of a conventional example that has been generally used. FIG. 1 is a plan view and FIG. 2 is a side sectional view.
図において、１aはＰ型シリコン単結晶の半導
体基板である。１１aは基板１aに設けられ測定圧
力Pnが導入される圧力導入孔である。２aは基板
１aにＮ型シリコン単結晶膜をエピタキシヤル成
長させたエピタキシヤル成長層である。３aは透
明なバイレツクスガラスよりなる絶縁カバーで、
エピタキシヤル成長層２aに陽極接続されている。
３１aは絶縁キヤツプ３aの圧力導入孔２aに対向
する位置に設けられた凹部である。４aは凹部３
１aの表面にアルミ材が蒸着されて形成された固
定電極である。固定電極４aはエピタキシヤル成
長層２aを移動電極として可変静電容量Cnを構成
する。５１a，５２aはエピタキシヤル成長層２a
より外部に引き出されたリード層である。６１a，
６２aは、それぞれリード層５１a，５２aに接続
された外部端子である。 In the figure, 1 a is a P-type silicon single crystal semiconductor substrate. 11 a is a pressure introduction hole provided in the substrate 1 a and into which the measurement pressure P n is introduced. 2 a is an epitaxially grown layer in which an N-type silicon single crystal film is epitaxially grown on the substrate 1 a . 3 a is an insulating cover made of transparent Virex glass,
It is anodically connected to the epitaxial growth layer 2a .
31a is a recess provided in a position facing the pressure introduction hole 2a of the insulating cap 3a . 4 a is concave part 3
This is a fixed electrode formed by vapor-depositing aluminum material on the surface of 1a . The fixed electrode 4 a constitutes a variable capacitance C n using the epitaxial growth layer 2 a as a moving electrode. 51 a and 52 a are epitaxial growth layers 2 a
This is a lead layer that is drawn out further to the outside. 61 a ,
62 a are external terminals connected to the lead layers 51 a and 52 a , respectively.
以上の構成において、圧力導入孔１１aに導入
された測定圧pnの変化によつて、エピタキシヤ
ル成長層２aと固定電極４aとの可変静電容量Cnは
変化する。この変化量を外部端子６１a，６２aよ
り出力することにより、圧力を検出することがで
きる。 In the above configuration, the variable capacitance C n between the epitaxial growth layer 2 a and the fixed electrode 4 a changes depending on the change in the measured pressure p n introduced into the pressure introduction hole 11 a . Pressure can be detected by outputting this amount of change from external terminals 61 a and 62 a .
このようなものにおいては、エピタキシヤル成
長層２aとリード層５１a，５２aとの間に絶縁を
とらなければならないため、たとえば、エピタキ
シヤル成長層２aをＮ型シリコン層とし、リード
層５１a，５２aをＰ型シリコン層とすることによ
りｐ−ｎ接合による絶縁をはかつている。 In such a device, insulation must be provided between the epitaxial growth layer 2a and the lead layers 51a and 52a , so for example, the epitaxial growth layer 2a is an N-type silicon layer and the lead layer is By using P-type silicon layers 51a and 52a , insulation by a pn junction is achieved.
しかしながら、このようにｐ−ｎ接合による絶
縁を行つても、固定電極４ａとエピタキシヤル成
長層２a間の電極間浮遊容量Csが存在し、この浮
遊容量Csは、固定電極４aとエピタキシヤル成長
層２aとで構成される可変静電容量C-よりも大き
く、かつ、この浮遊容量Csは周囲温度の変化によ
つて変化してしまう為、正確な圧力の測定ができ
ない。 However, even if insulation is performed by the p-n junction in this way, there is an interelectrode stray capacitance C s between the fixed electrode 4 a and the epitaxial growth layer 2 a , and this stray capacitance C s exists between the fixed electrode 4 a and the epitaxial growth layer 2 a . Since the floating capacitance C s is larger than the variable capacitance C − formed by the epitaxial growth layer 2 a and changes due to changes in the ambient temperature, accurate pressure measurement is not possible.
本発明の目的は、浮遊容量が小さく、周囲温度
の変化の影響が少い半導体容量形圧力センサを提
供するにある。 An object of the present invention is to provide a semiconductor capacitive pressure sensor that has a small stray capacitance and is less affected by changes in ambient temperature.
この目的を達成するために、本発明は半導体基
板と、該半導体基板の一面に形成された移動電極
と、該移動電極に対向して設けられた該移動電極
と可変静電容量を構成する固定電極とを具備する
半導体容量形圧力センサにおいて、
前記半導体基板の前記固定電極に対向する面の
表面全面にエピタキシヤル成長によつて形成され
た移動電極層と、該移動電極層に不純物が拡散さ
れて形成され前記移動電極層を前記固定電極に対
向する移動電極の部分と前記固定電極に対向しな
い部分とに絶縁分離し前記移動電極と前記半導体
基板との間の浮遊容量が小さくなるように該移動
電極を囲んで設けられかつ前記移動電極のガード
電極としても機能するリング状の絶縁層とを具備
したことを特徴とする半導体容量形圧力センサを
構成したものである。 To achieve this object, the present invention includes a semiconductor substrate, a movable electrode formed on one surface of the semiconductor substrate, and a fixed electrode that forms a variable capacitance with the movable electrode provided opposite to the movable electrode. A semiconductor capacitive pressure sensor comprising: a movable electrode layer formed by epitaxial growth on the entire surface of the semiconductor substrate facing the fixed electrode; and an impurity diffused into the movable electrode layer. The movable electrode layer is formed by insulating and separating the movable electrode layer into a portion of the movable electrode facing the fixed electrode and a portion not facing the fixed electrode, so that stray capacitance between the movable electrode and the semiconductor substrate is reduced. This semiconductor capacitive pressure sensor is characterized in that it includes a ring-shaped insulating layer that surrounds a moving electrode and also functions as a guard electrode for the moving electrode.
以下、本発明の実施例について説明する。 Examples of the present invention will be described below.
第３図、第４図は、本発明の一実施例の構成説
明図で、第３図は正面図、第４図は第３図のＡ−
Ａ断面図である。 3 and 4 are configuration explanatory diagrams of one embodiment of the present invention, where FIG. 3 is a front view and FIG. 4 is a
It is an A sectional view.
図において、１はＰ型シリコン単結晶の半導体
基板である。１１は基板１に設けられ測定圧力
Pnが導入される圧力導入孔で、基板１にダイア
フラムを構成する。２は基板１にＮ型シリコン単
結晶膜をエピタキシヤル成長させたエピタキシヤ
ル成長層で、移動電極層を構成する。３は透明な
パイレツクスガラスよりなる絶縁カバーで、エピ
タキシヤル成長層２に陽極接続されている。２１
はエピタキシヤル成長層の圧力導入孔１１に対向
する位置に設けられ、絶縁カバー３と基準室２２
を構成し、基準圧力Ppの導入される凹部である。
３１は絶縁カバー３の、基準室２２に面する面に
設けられた固定電極である。４３は、エピタキシ
ヤル層２の固定電極３１に面する面にリング状に
不純物が拡散されてＰ型半導体として形成された
絶縁層で、Ｎ型シリコン単結晶膜よりなる円板状
の移動電極４１と、移動電極４１と同心円状に設
けられた比較電極４２とを囲むように形成されて
いる。絶縁層４３は、移動電極４１が固定電極３
１に対応して必要最小限であるようにして、移動
電極４１と半導体基板１との間の浮遊容量Csが小
さくなるように構成されている。而して、絶縁層
４３はガード電極としても機能する。 In the figure, 1 is a P-type silicon single crystal semiconductor substrate. 11 is provided on the substrate 1 to measure the pressure
A diaphragm is formed in the substrate 1 by the pressure introduction hole into which P n is introduced. Reference numeral 2 denotes an epitaxial growth layer in which an N-type silicon single crystal film is epitaxially grown on the substrate 1, and constitutes a moving electrode layer. 3 is an insulating cover made of transparent Pyrex glass, which is anodically connected to the epitaxial growth layer 2. 21
is provided at a position facing the pressure introduction hole 11 of the epitaxial growth layer, and is connected to the insulating cover 3 and the reference chamber 22.
, and is the recess into which the reference pressure P p is introduced.
31 is a fixed electrode provided on the surface of the insulating cover 3 facing the reference chamber 22. Reference numeral 43 denotes an insulating layer formed as a P-type semiconductor by diffusing impurities in a ring shape on the surface of the epitaxial layer 2 facing the fixed electrode 31, and a disk-shaped movable electrode 41 made of an N-type silicon single crystal film. and a comparison electrode 42 provided concentrically with the moving electrode 41. The insulating layer 43 has a movable electrode 41 and a fixed electrode 3.
The structure is such that the stray capacitance C s between the moving electrode 41 and the semiconductor substrate 1 is reduced to the necessary minimum value corresponding to the above. Thus, the insulating layer 43 also functions as a guard electrode.
４１１，４２１は、それぞれ、移動電極４１、
あるいは、比較電極４２と半導体基板１との電気
的抵抗を少くするために設けられた埋込みn+層
である。５１，５２はエピタキシヤル成長層２に
設けられＮ型半導体で構成され、それぞれ、移動
電極４１、比較電極４２に一端が固定されたリー
ドである。５３はエピタキシヤル成長層２に設け
られ、Ｐ型半導体からなり、リード５１，５２を
絶縁すると共にリード５１，５２のガードの役目
もするリードである。５４はエピタキシヤル成長
層２に設けられ、Ｎ型半導体からなるリードで、
アルミニウム材よりなるパツド６を介して固定電
極３１に一端が接続されている。５５はエピタキ
シヤル成長層２に設けられＰ型半導体からなり、
リード５４をエピタキシヤル成長層２から絶縁す
る絶縁層である。６１，６２，６３，６４は、そ
れぞれ、リード５１，５２，５３，５４に接続さ
れた外部端子である。７１は固定電極３１に対向
するエピタキシヤル成長層２に設けられ、移動電
極４と固定電極３１との間の電極間の誘電率とほ
ぼ等しく、かつ絶縁性が高い誘電体膜で、この場
合は、約1000Åの厚さに管理された酸化珪素膜
（SiO2）が用いられている。７２，７３，７４は
エピタキシヤル層２の外気接触部分を保護する保
護膜で、この場合は、７２は酸化珪素膜
（SiO2）、７３は窒化珪素膜（Si3N4）、７４は酸
化珪素が用いられている。８は半導体基板１の圧
力導入孔１１が設けられている側に取付けられ
た、この場合はパイレツクスガラスよりなる絶縁
カバーである。 411 and 421 are moving electrodes 41 and 421, respectively.
Alternatively, it is a buried n + layer provided to reduce the electrical resistance between the comparison electrode 42 and the semiconductor substrate 1. Leads 51 and 52 are provided in the epitaxial growth layer 2 and are made of an N-type semiconductor, and have one end fixed to the moving electrode 41 and the comparison electrode 42, respectively. A lead 53 is provided in the epitaxial growth layer 2, is made of a P-type semiconductor, and serves to insulate the leads 51 and 52 and also serves as a guard for the leads 51 and 52. 54 is a lead provided in the epitaxial growth layer 2 and made of an N-type semiconductor;
One end is connected to a fixed electrode 31 via a pad 6 made of aluminum material. 55 is provided in the epitaxial growth layer 2 and is made of a P-type semiconductor;
This is an insulating layer that insulates the lead 54 from the epitaxial growth layer 2. 61, 62, 63, and 64 are external terminals connected to leads 51, 52, 53, and 54, respectively. 71 is a dielectric film provided in the epitaxial growth layer 2 facing the fixed electrode 31 and having a dielectric constant almost equal to the interelectrode dielectric constant between the movable electrode 4 and the fixed electrode 31 and high insulating property; A silicon oxide film (SiO 2 ) controlled to a thickness of approximately 1000 Å is used. 72, 73, and 74 are protective films that protect the parts of the epitaxial layer 2 that come into contact with the outside air; in this case, 72 is a silicon oxide film (SiO 2 ), 73 is a silicon nitride film (Si 3 N 4 ), and 74 is an oxide film. Silicon is used. Reference numeral 8 denotes an insulating cover made of Pyrex glass, which is attached to the side of the semiconductor substrate 1 on which the pressure introduction hole 11 is provided.
以上の構成において、移動電極４１は、絶縁層
４３によつて、エピタキシヤル成長層２の部分か
ら絶縁シールドされているので、移動電極４１と
固定電極３１の間の電界は電極面に垂直になり、
可変静電容量Cn以外の、電極間浮遊容量Csを小
さくすることができる。したがつて、周囲温度の
変化の影響が少い半導体容量形圧力センサを得る
ことができる。 In the above configuration, the moving electrode 41 is insulated and shielded from the epitaxial growth layer 2 by the insulating layer 43, so the electric field between the moving electrode 41 and the fixed electrode 31 is perpendicular to the electrode surface. ,
Interelectrode stray capacitance C s other than variable capacitance C n can be reduced. Therefore, it is possible to obtain a semiconductor capacitive pressure sensor that is less affected by changes in ambient temperature.
更に、凹部２１の表面には、移動電極４１と固
定電極３１との間の電極間の誘電率とほぼ等し
く、かつ絶縁性が高い誘電体膜７１が形成されて
いるので、可変静電容量電極としての機能を損わ
ずに、固定電極３１と移動電極４１間の直流抵抗
に影響を受けないものが得られる。 Furthermore, since a dielectric film 71 having a dielectric constant substantially equal to the interelectrode dielectric constant between the movable electrode 41 and the fixed electrode 31 and having high insulation properties is formed on the surface of the recess 21, the variable capacitance electrode It is possible to obtain something that is not affected by the DC resistance between the fixed electrode 31 and the moving electrode 41 without impairing its function.
なお、本発明は、ガード電極４３を使用した、
いわゆる三端子構造の静電容量検出方式を採用し
たものである。 Note that the present invention uses the guard electrode 43.
This uses a capacitance detection method with a so-called three-terminal structure.
以上説明したように、本発明によれば、周囲温
度の変化の影響が少い半導体容量形圧力センサを
実現することができる。 As described above, according to the present invention, it is possible to realize a semiconductor capacitive pressure sensor that is less affected by changes in ambient temperature.
第１図、第２図は従来より一般に使用されてい
る従来例の構成説明図で、第１図は平面図、第２
図は側断面図、第３図、第４図は本発明の一実施
例の構成説明図で、第３図は正面図、第４図は第
３図のＡ−Ａ断面図である。
１……半導体基板、１１……圧力導入孔、２…
…エピタキシヤル成長層、２１……凹部、２２…
…基準室、３……絶縁カバー、３１……固定電
極、４１……移動電極、４１１，４２１……n+
層、４２……比較電極、４３……絶縁層、５１，
５２，５３，５４……リード、５５……絶縁層、
６……パツド、６１〜６４……外部端子、７１…
…誘電体膜、７２，７３，７４……保護膜、８…
…絶縁カバー、Pn……測定圧、Pp……基準圧、
Cn……測定静電容量、Cs……浮遊容量。
Figures 1 and 2 are explanatory diagrams of the configuration of a conventional example that has been commonly used. Figure 1 is a plan view,
FIG. 3 is a side sectional view, FIGS. 3 and 4 are explanatory diagrams of the configuration of an embodiment of the present invention, FIG. 3 is a front view, and FIG. 4 is a sectional view taken along line AA in FIG. 3. 1...Semiconductor substrate, 11...Pressure introduction hole, 2...
...Epitaxial growth layer, 21...Concavity, 22...
... Reference chamber, 3 ... Insulating cover, 31 ... Fixed electrode, 41 ... Moving electrode, 411, 421 ... n +
Layer, 42... Reference electrode, 43... Insulating layer, 51,
52, 53, 54...Lead, 55...Insulating layer,
6... Pad, 61-64... External terminal, 71...
...Dielectric film, 72, 73, 74... Protective film, 8...
...Insulation cover, P n ...Measurement pressure, P p ...Reference pressure,
C n : Measured capacitance, C s : Stray capacitance.
Claims (1)
と、 該移動電極に対向して設けられ該移動電極と可
変静電容量を構成する固定電極と を具備する半導体容量形圧力センサにおいて、 前記半導体基板の前記固定電極に対向する面の
表面全面にエピタキシヤル成長によつて形成され
た移動電極層と、 該移動電極層に不純物が拡散されて形成され前
記移動電極層を前記固定電極に対向する移動電極
の部分と前記固定電極に対向しない部分とに絶縁
分離し前記移動電極と前記半導体基板との間の浮
遊容量が小さくなるように該移動電極を囲んで設
けられかつ前記移動電極のガード電極としても機
能するリング状の絶縁層と を具備したことを特徴とする半導体容量形圧力セ
ンサ。 ２ 移動電極表面を固定電極との間の電極間の誘
電率とほぼ等しく絶縁性の高い絶縁被膜で覆つた
事を特徴とする特許請求の範囲第１項記載の半導
体容量形圧力センサ。[Scope of Claims] 1. A semiconductor capacitive pressure device comprising: a moving electrode formed on one surface of the semiconductor substrate; and a fixed electrode provided opposite to the moving electrode and forming a variable capacitance with the moving electrode. The sensor includes: a movable electrode layer formed by epitaxial growth on the entire surface of the surface of the semiconductor substrate facing the fixed electrode; and an impurity diffused into the movable electrode layer to form the movable electrode layer. The movable electrode is insulated and separated into a portion of the movable electrode that faces the fixed electrode and a portion that does not face the fixed electrode, and is provided surrounding the movable electrode so that stray capacitance between the movable electrode and the semiconductor substrate is reduced. A semiconductor capacitive pressure sensor characterized by comprising a ring-shaped insulating layer that also functions as a guard electrode for a moving electrode. 2. The semiconductor capacitive pressure sensor according to claim 1, characterized in that the surface of the movable electrode is covered with an insulating film having high insulating properties and having substantially the same dielectric constant as the inter-electrode dielectric constant between the movable electrode and the fixed electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13694283A JPS6029629A (en) | 1983-07-27 | 1983-07-27 | Semiconductor capacity type pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13694283A JPS6029629A (en) | 1983-07-27 | 1983-07-27 | Semiconductor capacity type pressure sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6029629A JPS6029629A (en) | 1985-02-15 |
| JPH0420131B2 true JPH0420131B2 (en) | 1992-03-31 |
Family
ID=15187132
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13694283A Granted JPS6029629A (en) | 1983-07-27 | 1983-07-27 | Semiconductor capacity type pressure sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6029629A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2211359A2 (en) | 2009-01-22 | 2010-07-28 | NGK Insulators, Ltd. | A layered inductor |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62156879A (en) * | 1985-12-28 | 1987-07-11 | Nec Corp | Semiconductor pressure detector and manufacture of the same |
| JP2514067Y2 (en) * | 1987-06-29 | 1996-10-16 | 京セラ株式会社 | Ceramic transformer |
| JPS6478830A (en) * | 1987-09-22 | 1989-03-24 | Nippon Samikon Kk | Composite of fiber-reinforced plastic and concrete or the like |
| JP3367113B2 (en) | 1992-04-27 | 2003-01-14 | 株式会社デンソー | Acceleration sensor |
| DE29821563U1 (en) * | 1998-12-02 | 2000-07-13 | Impella Cardiotechnik AG, 52074 Aachen | Pressure sensor |
-
1983
- 1983-07-27 JP JP13694283A patent/JPS6029629A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2211359A2 (en) | 2009-01-22 | 2010-07-28 | NGK Insulators, Ltd. | A layered inductor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6029629A (en) | 1985-02-15 |
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