JPS6216677Y2 - - Google Patents
Info
- Publication number
- JPS6216677Y2 JPS6216677Y2 JP1980120903U JP12090380U JPS6216677Y2 JP S6216677 Y2 JPS6216677 Y2 JP S6216677Y2 JP 1980120903 U JP1980120903 U JP 1980120903U JP 12090380 U JP12090380 U JP 12090380U JP S6216677 Y2 JPS6216677 Y2 JP S6216677Y2
- Authority
- JP
- Japan
- Prior art keywords
- sensor
- ion
- gate
- guard electrode
- fet
- 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
Links
- 239000007788 liquid Substances 0.000 claims description 6
- 230000005669 field effect Effects 0.000 claims description 3
- 239000003792 electrolyte Substances 0.000 claims description 2
- 150000002500 ions Chemical class 0.000 description 13
- 239000010410 layer Substances 0.000 description 9
- 238000005259 measurement Methods 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 9
- 150000002739 metals Chemical class 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000006698 induction Effects 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical class O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000012790 adhesive layer Substances 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- -1 ion ion Chemical class 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Solid State Image Pick-Up Elements (AREA)
Description
【考案の詳細な説明】
本考案はゲート絶縁形電界効果トランジスタ
（以下、FETセンサと略称する。）を用いたイオ
ンセンサ装置、特に交流誘導障害を除去し、常に
正確なイオン濃度が測定できるイオンセンサ装置
に関するものである。[Detailed description of the invention] The present invention is an ion sensor device using an insulated gate field effect transistor (hereinafter abbreviated as FET sensor), which eliminates alternating current induced disturbances and allows accurate ion concentration measurement at all times. The present invention relates to a sensor device.
従来、この種のイオンセンサ装置に用いられる
FETセンサとしてたとえば第１図に示す構造の
ものが知られている。同図において、１はＰ形の
シリコン基板であり、この基板１上にｎ形のドレ
イン２、およびセンサソース３が形成されてい
る。４，５，６は共通ドレイン層２、センサソー
ス３、およびシリコン基板１の各電極部であり、
７はセンサゲート部で、第２図にその横断面が示
されている。 Traditionally, this type of ion sensor device uses
For example, a structure shown in FIG. 1 is known as an FET sensor. In the figure, reference numeral 1 denotes a P-type silicon substrate, on which an N-type drain 2 and a sensor source 3 are formed. 4, 5, and 6 are the common drain layer 2, the sensor source 3, and each electrode portion of the silicon substrate 1;
Reference numeral 7 denotes a sensor gate portion, a cross section of which is shown in FIG.
この第２図から明らかなように、ゲート部７に
はシリコン基板１上に形成された酸化シリコン層
８と室化シリコン層９との２層構造を有し、セン
サゲート部７にはたとえばイオン感応層１０が被
覆されている。 As is clear from FIG. 2, the gate section 7 has a two-layer structure of a silicon oxide layer 8 and a silicon oxide layer 9 formed on the silicon substrate 1, and the sensor gate section 7 has, for example, an ion ion layer. A sensitive layer 10 is coated.
上記構成のFETセンサと液絡式比較電極から
なるイオンセンサ装置は第３図の回路に示すよう
に電解液１２の電位を一定とするための比較電極
１３とともに容器１１内の被検液１２に浸漬され
ている。FETセンサのドレイン電極２には電圧
源Vdの正電位を接続し、ソース電極３には定電
流回路１４を接続してソース・フオロア回路とし
て作動させている。この回路構成でゲート絶縁膜
と電解液間の界面電位によりゲート絶縁膜下の半
導体表面で電導度を変化させ、この時の界面電位
変化をソース電位変化Vsとして取り出す。この
Vsはイオン濃度の対数と直線関係にあるため、
このVsを測定することによりイオン濃度を測定
することができる。 As shown in the circuit of FIG. 3, the ion sensor device consisting of the FET sensor and the liquid junction type comparison electrode configured as described above is connected to the test liquid 12 in the container 11 together with the comparison electrode 13 for keeping the potential of the electrolytic solution 12 constant. Immersed. A positive potential of a voltage source Vd is connected to the drain electrode 2 of the FET sensor, and a constant current circuit 14 is connected to the source electrode 3 to operate as a source follower circuit. With this circuit configuration, the conductivity is changed on the semiconductor surface under the gate insulating film by the interface potential between the gate insulating film and the electrolyte, and the change in the interface potential at this time is extracted as the source potential change Vs. this
Since Vs has a linear relationship with the logarithm of the ion concentration,
By measuring this Vs, the ion concentration can be measured.
しかしながら上述の回路で溶液中のイオン濃度
の測定を行う場合、主として室内交流配線や、床
を洩れる交流が接地線経由でセンサ回路に入るな
どの交流誘導障害により、ソース電位の値が変化
し正確なイオン濃度の測定が困難となることがあ
る。特にインピーダンスの高い、例えば100KΩ
以上の小型の液絡式比較電極を用いたり、ドレン
電流が30μＡ以下の場合には上記交流誘導障害が
大きく実際上測定は困難である。このことは小型
のFETセンサの場合、交流誘導障害が大きくな
ることを意味し、特に生体内に挿入して生体中の
イオン濃度を測定する超小型のFETセンサにお
いて測定が非常に困難で、時には測定不能にいた
ることもある。 However, when measuring the ion concentration in a solution using the circuit described above, the value of the source potential changes due to AC induction disturbances, such as indoor AC wiring or AC leaking through the floor entering the sensor circuit via the ground wire. It may be difficult to measure the ion concentration. Particularly high impedance, e.g. 100KΩ
When the above-mentioned small liquid junction type reference electrode is used or when the drain current is 30 μA or less, the above-mentioned alternating current induction disturbance is large and measurement is difficult in practice. For small FET sensors, this means that alternating current induction disturbances are large, and measurements are especially difficult for ultra-small FET sensors that are inserted into living organisms to measure ion concentrations in living organisms, and sometimes It may even become impossible to measure.
本考案者らは、上述の交流誘導障害を除去して
信号のＳ／Ｎ比の向上を計るために、生体に接触
するセンサ回路と他の回路を絶縁増巾器で結合
し、かつセンサ回路をシールドし、これをガード
電極に接続して生体に流れる交流を主とする外部
信号がセンサ回路に流れず、常に正確な測定を行
うことができることを見い出し、更に鋭意検討し
た結果、ガード電極をセンサゲートに近接して一
体に設けることによりFETセンサの特徴をその
まま有し、かつ測定時交流障害などのないイオン
センサ装置を提供することが可能となつたのであ
る。 In order to improve the S/N ratio of the signal by removing the AC induced disturbances mentioned above, the present inventors connected the sensor circuit that comes into contact with the living body with other circuits using an isolation amplifier, and We discovered that by shielding the body and connecting it to a guard electrode, external signals, mainly alternating current, flowing through the living body would not flow to the sensor circuit, allowing accurate measurements to be taken at all times.After further study, we discovered that the guard electrode By integrally providing the ion sensor near the sensor gate, it has become possible to provide an ion sensor device that has the characteristics of an FET sensor and is free from alternating current disturbances during measurement.
次に本考案のイオンセンサを図面にて説明す
る。第４図は第１図に示すFETセンサにガード
電極１５を一体に設けたものである。かかるガー
ド電極１５はFETセンサのゲート７と電気的な
導通を保つていればよく、その取付け位置や形状
は任意に選択することができる。しかしながら体
内に挿入する程小型であというFETセンサの特
徴を生すためにはガード電極も小型とする必要が
ある。そのためガード電極はFETセンサのゲー
トに出来るだけ近づけ、その形状も小型にするこ
とが好ましい。ゲートとガード電極の距離は実用
上１mm以下とすることが望まれる。またガード電
極の形状はどのようなものでもよいが第４図に示
す細長状のFETセンサの場合にはセンサの形状
に沿つた細長状とすることが好ましい。かかるガ
ード電極の材質は銅、アルミ、金などの導電性金
属であれば使用できるが、特に生体中に挿入して
使用するFETセンサには金、白金、銀などの耐
腐食性の大きい貴金属が好ましい。これらの金属
はFETセンサの表面に蒸着やプリントなどの公
知の手段により設けることができる。特に蒸着手
段を使用する場合には金属とFETセンサとの接
着力を向上させるためTa2O5、Si3N4などのFET
基板表面にクロム層などのSi3N4との接着性が良
好でかつ金属との接着性の高い接着層を設け、上
記接着層の上に金属を蒸着することにより、測定
中、金属層の剥離を防止することができる。また
蒸着等により設けた金属上にさらにこれらの金属
をメツキすることも、液に腐食されにくい厚いガ
ード電極が得られ、好ましい方法である。 Next, the ion sensor of the present invention will be explained with reference to the drawings. FIG. 4 shows the FET sensor shown in FIG. 1 in which a guard electrode 15 is integrally provided. The guard electrode 15 only needs to maintain electrical continuity with the gate 7 of the FET sensor, and its mounting position and shape can be arbitrarily selected. However, in order to achieve the characteristics of an FET sensor that is small enough to be inserted into the body, the guard electrode must also be small. Therefore, it is preferable that the guard electrode be placed as close as possible to the gate of the FET sensor and that its shape be small. Practically speaking, it is desirable that the distance between the gate and the guard electrode be 1 mm or less. Further, the shape of the guard electrode may be any shape, but in the case of the elongated FET sensor shown in FIG. 4, it is preferable to make it elongated along the shape of the sensor. The guard electrode can be made of conductive metals such as copper, aluminum, and gold; however, highly corrosion-resistant noble metals such as gold, platinum, and silver are particularly recommended for FET sensors that are inserted into living organisms. preferable. These metals can be provided on the surface of the FET sensor by known means such as vapor deposition or printing. Especially when using vapor deposition means, FETs such as Ta 2 O 5 and Si 3 N 4 are used to improve the adhesion between the metal and the FET sensor.
By providing an adhesive layer such as a chromium layer that has good adhesion to Si 3 N 4 and high adhesion to metal on the substrate surface, and depositing metal on the adhesive layer, the metal layer can be easily removed during measurement. Peeling can be prevented. Further, plating these metals on the metals provided by vapor deposition or the like is also a preferable method since a thick guard electrode that is less likely to be corroded by the liquid can be obtained.
上述の金属層はガード電極として作動させかつ
使用中の剥離防止のためには通常数千Ａ゜以上の
厚さが好ましい。 The thickness of the above-mentioned metal layer is normally preferably several thousand amps or more in order to function as a guard electrode and to prevent peeling during use.
このようにして得られたFETセンサの各電極
及びガード電極にリード線をつけた後、カテーテ
ルに埋込みボンデイング部及びリード線を保護
し、液絡式比較電極を用いて生体での測定を第５
図の回路を用いて行うことができる。 After attaching lead wires to each electrode and guard electrode of the FET sensor obtained in this way, it was embedded in a catheter to protect the bonding part and the lead wires, and measurements were taken in the living body using a liquid junction type reference electrode.
This can be done using the circuit shown in the figure.
以上のように本考案のイオンセンサ装置はガー
ド電極とFETセンサを一体化することにより非
常に小型で、かつアイソレーシヨンアンプのガー
ドラインを経由して交流成分のみをバイパスさせ
るなどの方法により交流障害などが防止でき、常
に正確な測定を行うことができ実用上非常に有用
である。 As described above, the ion sensor device of the present invention is extremely compact by integrating the guard electrode and the FET sensor, and also uses methods such as bypassing only the AC component via the guard line of the isolation amplifier. This is extremely useful in practice as it prevents failures and allows accurate measurements to be taken at all times.
第１図はFETセンサの平面図であり、第２図
はゲート部断面図であり、第３図はFETセンサ
を使用した測定回路であり、第４図はFETセン
サにガード電極を一体に設けた図であり、第５図
は第４図に示すガード電極を一体化したFETセ
ンサを使用した回路図である。
２……ドレイン、３……ソース、７……ゲー
ト、１５……ガード電極。
Figure 1 is a plan view of the FET sensor, Figure 2 is a cross-sectional view of the gate, Figure 3 is a measurement circuit using the FET sensor, and Figure 4 is a guard electrode integrated with the FET sensor. FIG. 5 is a circuit diagram using the FET sensor integrated with the guard electrode shown in FIG. 4. 2...Drain, 3...Source, 7...Gate, 15...Guard electrode.
Claims (1)
るセンサゲートをもつ絶縁ゲート型電界効果トラ
ンジスタと、液絡式比較電極からなるイオンセン
サ装置であつて、該絶縁ゲート型電界効果トラン
ジスタのセンサゲートに近接して交流誘導障害を
除去するガード電極を一体に設けたことを特徴と
するイオンセンサ装置。 An ion sensor device comprising an insulated gate field effect transistor having a sensor gate that generates an interfacial potential according to the ion activity in an electrolyte, and a liquid junction type reference electrode, the sensor gate of the insulated gate field effect transistor An ion sensor device characterized by integrally providing a guard electrode close to the ion sensor for removing AC induced interference.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1980120903U JPS6216677Y2 (en) | 1980-08-25 | 1980-08-25 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1980120903U JPS6216677Y2 (en) | 1980-08-25 | 1980-08-25 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5742945U JPS5742945U (en) | 1982-03-09 |
| JPS6216677Y2 true JPS6216677Y2 (en) | 1987-04-27 |
Family
ID=29481576
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1980120903U Expired JPS6216677Y2 (en) | 1980-08-25 | 1980-08-25 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6216677Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1228894A (en) * | 1983-08-24 | 1987-11-03 | Hendrikus C.G. Ligtenberg | Apparatus for selectively measuring ions in a liquid |
| JPH0465273U (en) * | 1990-10-18 | 1992-06-05 |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53109690A (en) * | 1977-03-07 | 1978-09-25 | Hewlett Packard Yokogawa | Temperatureecompensated los transistor type ph meter |
| JPS54128791A (en) * | 1978-03-30 | 1979-10-05 | Shingijutsu Kaihatsu Jigyodan | Ion sensor using semiconductor field effect |
-
1980
- 1980-08-25 JP JP1980120903U patent/JPS6216677Y2/ja not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53109690A (en) * | 1977-03-07 | 1978-09-25 | Hewlett Packard Yokogawa | Temperatureecompensated los transistor type ph meter |
| JPS54128791A (en) * | 1978-03-30 | 1979-10-05 | Shingijutsu Kaihatsu Jigyodan | Ion sensor using semiconductor field effect |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5742945U (en) | 1982-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4508613A (en) | Miniaturized potassium ion sensor | |
| US5944970A (en) | Solid state electrochemical sensors | |
| US20110156177A1 (en) | Reducing capacitive charging in electronic devices | |
| US5078855A (en) | Chemical sensors and their divided parts | |
| Janata | Electrochemistry of chemically sensitive field effect transistors | |
| JPH0370784B2 (en) | ||
| JPH1062383A (en) | Electrochemical sensor | |
| JPH07109413B2 (en) | Chemically sensitive transducer | |
| JPS6216677Y2 (en) | ||
| Pan et al. | Using polypyrrole as the contrast pH detector to fabricate a whole solid-state pH sensing device | |
| JPH06308078A (en) | Ion-sensing type field-effect transistor chip | |
| JPS59176662A (en) | Semiconductor sensor | |
| JPH0469338B2 (en) | ||
| JPH0452409B2 (en) | ||
| EP0190005A2 (en) | Ambient sensing devices with isolation | |
| JPS6154438A (en) | Fluoride ion sensitive field-effect transistor | |
| JP3390193B2 (en) | Potential measurement circuit | |
| Van den Vlekkert | Ion-sensitive field effect transistors | |
| JPH0421815B2 (en) | ||
| JPH0612529Y2 (en) | Biosensor and its sensor plate | |
| TWI579561B (en) | Cerium oxide ph sensor and method of producing the same | |
| JPH0740208Y2 (en) | Sensor for specimen component detection | |
| JP2526689B2 (en) | Semiconductor sensor and driving method thereof | |
| JPS58167952A (en) | Hydrogen ion densitometer | |
| JPH04186153A (en) | Planer type ion sensor |