JPS6073352A - Chemical fet sensor - Google Patents
Chemical fet sensorInfo
- Publication number
- JPS6073352A JPS6073352A JP58180234A JP18023483A JPS6073352A JP S6073352 A JPS6073352 A JP S6073352A JP 58180234 A JP58180234 A JP 58180234A JP 18023483 A JP18023483 A JP 18023483A JP S6073352 A JPS6073352 A JP S6073352A
- Authority
- JP
- Japan
- Prior art keywords
- film
- sensor
- oxide film
- chemical
- wiring
- 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
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/414—Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
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- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Biochemistry (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- Molecular Biology (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、血液分析装置用センサなど試料溶液中の化学
物質の濃度を測定するための化学ＦＥＴセンサに関する
。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a chemical FET sensor for measuring the concentration of a chemical substance in a sample solution, such as a sensor for a blood analyzer.
化学ＦＥＴセンサとＭＯＳＦＥＴを同一半導体基板上に
形成したものに
［Ａ、ｌ（ＡＥＭＭＥＲＬＩ 、Ｊ、 ＪＡＮＡＴＡ。A chemical FET sensor and a MOSFET formed on the same semiconductor substrate [AEMMERLI, J, JANATA.
Ｈ６Ｎ、 Ｂｌ（ＯＷＮ Ａｎａｌ、 Ｃｈｉｍ、 Ａ
ｃｔａ、、 １４４（１９８２）１１５−１２１Ｊがあ
る。この化学ＦＥＴセンサのゲート部分の構造は、イオ
ン選択性の微小電極をゲート絶縁膜上に取り付けたもの
で、この微小電極部分のみを測定溶液につければ測定出
来る。ところで、［５ＴＡＮＬＥＹ Ｄ。H6N, Bl(OWN Anal, Chim, A
cta, 144 (1982) 115-121J. The structure of the gate portion of this chemical FET sensor is such that an ion-selective microelectrode is attached to a gate insulating film, and measurement can be performed by immersing only this microelectrode portion in a measurement solution. By the way, [5TANLEY D.
Ｍｏ５ｓ、ＣＵＲＴｉＳ Ｃ，ＪＯ）ＩＮｓＯＮ、ＪＩ
几１ＪＡＮＡＴＡ、１ＥＥＥ Ｔ几ＡＮＳＡＣＴＩＯＮ
ＳＯＮ’ＢｉＯＭＥＤＩＣＡＬ ＥＮＧｉＮＥＥＲ，Ｌ
ＮＧ。Mo5s, CURTiSC, JO) INsON, JI
几1JANATA, 1EEE T几ANSACTION
SON'BiOMEDICAL ENGiNEER, L
NG.
ＶＯＬ、 ＢＭＥ−２５、隘１ 、４９ （１９７８）
Ｊニ報告されでいる工うな、ＦＥＴのゲート絶縁膜の上
に直接イオン感応膜を付けた構造の化学ＦＥＴセンサを
前述のようにＭ ＯＳ Ｌ’！ Ｅ Ｔと一諸に半導体
基板上に形成しようとすると、化学ＦＥＴセンサはゲー
ト部分を直接測定溶液につけなければならないので、Ｍ
ＯＳＦＥＴの表面まで溶液につかることになり、従来の
ＭＯ８Ｆ’ＥＴの構造では、すぐ腐食を起こし動作に異
常をきたす。このため従来のＭＯ８Ｌｉ”ＥＴの構造で
は同一半導体基板上に化学ＦＩＤＴセンサと一諸に形成
して使用することが出来なかった。VOL, BME-25, No. 1, 49 (1978)
As previously reported, a chemical FET sensor with a structure in which an ion-sensitive film is directly attached on the gate insulating film of the FET is used as a MOS L'! If a chemical FET sensor is to be formed on a semiconductor substrate along with E T, the gate part must be directly immersed in the measurement solution, so M
The surface of the OSFET will be immersed in the solution, and in the conventional MO8F'ET structure, corrosion will occur immediately and abnormal operation will occur. For this reason, the conventional MO8Li"ET structure could not be used together with a chemical FIDT sensor on the same semiconductor substrate.
本発明の目的は、化学ＦＥＴセンサから得られる信号を
処理する回路を化学ＦＥＴセンサと一諸に同一半導体基
板上に形成して、センサチップ表面を直接、被測定溶液
に接触させることが出来る索子構造を提供することにあ
る。An object of the present invention is to form a circuit for processing signals obtained from a chemical FET sensor on the same semiconductor substrate as the chemical FET sensor, and to make it possible to bring the surface of the sensor chip into direct contact with a solution to be measured. The purpose is to provide a child structure.
化学Ｆ、 Ｅ ＴセンサとＭＯ８ＦＥＴセンサを同一半
導体基板上に形成し、ＭＯＳＦＥＴの表面部分に耐水膜
などをつければ一応の保護はできるが、耐水膜がついで
いる箇所とついてない箇所の境界部分から溶液が浸入し
、 Ａｊ配線などの腐食が発生する。また、この耐水膜
が厚いと化学ＦＥＴセンサと溶液間の熱伝導とＭＯＳＦ
ＥＴと溶液間の熱伝導に大きな差が生じるため、Ｍ、０
８ＦＥＴによる温度補償が出来なくなる。このためＭＯ
３Ｆ’ＥＴの膜構造は化学ＦＥＴと類似した構造とする
必要がある。また重責が起こりやすいＡＩ配線は採用し
ない構成としなければならない。そのために本発明では
配線及びゲート電極として全てｐｏｌｙ−８ｉ（ポリシ
リコン）またはＴａ＋Ｗ等のシリサイドを採用する。そ
の半導体基板表面の第一層目の酸化膜中に配線を形成し
、センサチップ全体に第二層目として５ｉＢＮ４等の耐
水膜を形成した。さらに化学ＦＥＴセンサ部分だけ、ま
たはセンサチップ全体に被測定化学物質に感応する感応
膜を形成すれｉＪ［４０８ＦＥＴに耐水性をもたせ、測
定溶液に接触させることができる。Chemical F, ET Sensors and MO8FET sensors are formed on the same semiconductor substrate and a water-resistant film is applied to the surface of the MOSFET to provide some protection, but from the boundary between the areas where the water-resistant film is applied and the areas where it is not. The solution will enter, causing corrosion of AJ wiring, etc. In addition, if this water-resistant film is thick, heat conduction between the chemical FET sensor and the solution will be reduced.
Since there is a large difference in heat conduction between ET and the solution, M,0
Temperature compensation by 8FET becomes impossible. For this reason, M.O.
The membrane structure of the 3F'ET needs to be similar to that of a chemical FET. In addition, the configuration must not include AI wiring, which is likely to cause heavy liability. For this reason, in the present invention, poly-8i (polysilicon) or silicide such as Ta+W is used for all wiring and gate electrodes. Wiring was formed in the first layer of oxide film on the surface of the semiconductor substrate, and a water-resistant film such as 5iBN4 was formed as the second layer over the entire sensor chip. Furthermore, by forming a sensitive film sensitive to the chemical substance to be measured only on the chemical FET sensor portion or on the entire sensor chip, the iJ[408 FET can be made water resistant and brought into contact with the measurement solution.
以下、本発明の一実施例を第１図により説明する。第１
図はｐ形Ｓｉ基板上に形成した化学ＦＥＴセンサ及びＭ
ＯＳＦＥＴの素子の断面を示したものであるＯｐ形Ｓｉ
基板１上に化学Ｆ’ＥＴセンサとＭＯＳＦＥＴを、分離
して形成するためにｐ形活散層３及び分離部分だけに酸
化膜５を厚く形成するＬＯＧＯ８（Ｌｏｃａｌ ０ｘｉ
ｄｉｚａｔｉｏｎ ｏｆＳｉｌｉｃｏｎ ）によシ素子
分離をおこなった。An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows a chemical FET sensor formed on a p-type Si substrate and M
Op type Si which shows the cross section of OSFET element
In order to separately form a chemical F'ET sensor and a MOSFET on the substrate 1, a thick oxide film 5 is formed only on the p-type active layer 3 and the separated part.
The elements were separated by dization of silicon.
ＭＯＳＦＥＴのゲート電極としてｐｏｌｙ−８ｉゲート
電極６を形成し、さらに各素子間ＭＯ８ＦＥＴどうしま
たはＭＯＳＦＥＴと化学ＦＥＴセンサとの配線もｐｏｌ
ｙ−８ｉ配線４で形成した。各素子ともｎチャネルＦｇ
Ｔなのでシんをドープしたｐｏｌｙ−８ｉを使用したが
、他の配線としてＴａやＷのシリサイドも可能である。A poly-8i gate electrode 6 is formed as the gate electrode of the MOSFET, and the wiring between the MO8FETs between each element or between the MOSFET and the chemical FET sensor is also formed as a pol.
It was formed with y-8i wiring 4. Each element has n-channel Fg
Since T is used, poly-8i doped with phosphor is used, but silicide of Ta or W is also possible as other wiring.
図右側の素子の化学Ｆ ｇ Ｔセンサの構造と左側の素
子のＭＯＳＦＥＴの構造と異なる点は、ＭＯＳＦＥＴの
ゲート電極に相等するものが化学ＦＥＴセンサにはない
だけで、第一層目に酸化膜５．第二層目に耐水絶縁膜と
してのＳｉ３Ｎ４膜７．第三層目にここではｐＨ応答す
る感応膜としてＴａ２０５膜８をゲート部分に層状に形
成しでいる。 ｎ＋拡散層２によって形成したソース及
びドレインを他の素子と接続する配線としてのｐｏｌｙ
−８ｉ 配＃ｉｉ４を第一層中に形成した。ＭＯ’５Ｆ
ＥＴでも同様に第一層の酸化膜中に配線及びゲート電極
のｐｏｌｙ−８ｔを形成し、第二層目にＳｉ３Ｎ４膜７
を形成しセンサチップを被測定溶液につけられるよう保
護している。さらに、第三層にｐＨ感応膜とし、でのＴ
ａ２０５膜８を形成している。第一層に配線及びゲート
電極を形成したため、ｐＨ測定用化学ＦＥＴセンサとＭ
ＯＳＦＥＴとの構造の違いはゲート電極の有無だけとな
っている。ＭＯＳＦＥＴのドレイン電流制御はゲート電
極の電位でおこなえる〇一方、化学ＦＥＴセンサは、感
応膜側を被測定溶液に接触させ、飽和カロメル電極等の
参照電極で被測定溶液に電位を与えることによシトレイ
ン電流を規定するが、この電位にさらにここでは被測定
溶液のｐＨ値によシ溶液とＴａ２Ｏ，膜との界面に生じ
る電位変化が加わる。この電位変化によりｐＨ測定用化
学ＦＥＴセンサが動作する。The difference between the structure of the chemical F g T sensor on the right side of the figure and the structure of the MOSFET on the left side is that the chemical FET sensor does not have an equivalent to the gate electrode of a MOSFET; 5. Si3N4 film as the second layer as a water-resistant insulating film7. As the third layer, a Ta205 film 8 is formed as a layer at the gate portion as a pH-responsive sensitive film. Poly as a wiring connecting the source and drain formed by the n+ diffusion layer 2 to other elements
-8i pattern #ii4 was formed in the first layer. MO'5F
In ET, wiring and gate electrode poly-8T are similarly formed in the first layer of oxide film, and Si3N4 film 7 is formed in the second layer.
to protect the sensor chip from being immersed in the solution to be measured. Furthermore, the third layer is a pH-sensitive film, and the T
A205 film 8 is formed. Since the wiring and gate electrode were formed on the first layer, the chemical FET sensor for pH measurement and M
The only difference in structure from OSFET is the presence or absence of a gate electrode. The drain current of a MOSFET can be controlled by the potential of the gate electrode.On the other hand, a chemical FET sensor can control the drain current by bringing the sensitive membrane side into contact with the solution to be measured and applying a potential to the solution to be measured using a reference electrode such as a saturated calomel electrode. The cell train current is defined, and to this potential is added the potential change that occurs at the interface between the cell solution, Ta2O, and the membrane depending on the pH value of the solution to be measured. This potential change causes the chemical FET sensor for pH measurement to operate.
この素子構造により、ｐＨ測定用化学ＦＥＴセンサとそ
の信号処理用の素子をワンチップ化したときの回路図を
第２図に示す。この回路はゲート電圧が零のときドレイ
ン電流が流扛ないエンノ・ンスメント形のＮＭＯ８によ
って構成された差動増幅回路であり、Ｑｌ とＱ２がダ
イナミック負荷用ＭＯ８ＦＥＴで、Ｑ３とＱ４が増幅用
であるが。FIG. 2 shows a circuit diagram when a chemical FET sensor for pH measurement and its signal processing element are integrated into one chip using this element structure. This circuit is a differential amplifier circuit composed of an enhancement type NMO8 in which no drain current flows when the gate voltage is zero, Ql and Q2 are MO8FETs for dynamic load, and Q3 and Q4 are for amplification. but.
Ｑ３だけ化学ＦＥＴセンサとしている。各素子のチャン
ネル長し、及びチャンネル幅Ｗの比Ｗ／Ｌの値を、それ
ぞれＱ、とＱ２では３．Ｑ３を５４゜Ｑ４を３０ ＃
Ｑ５ とＱ７は６．Ｑ６を１２とした。Only Q3 is a chemical FET sensor. The channel length of each element and the value of the ratio W/L of the channel width W are set to 3 for Q and Q2, respectively. Q3 is 54° Q4 is 30 #
Q5 and Q7 are 6. Q6 was set to 12.
このセンサチップを各種のｐＨ値からなる被測定溶液に
接触させ、センサ出力の変化・を詞べた結果を第３図に
示す。センサ出力としてｐＨ７付近では７８ｍＶ／ｐＨ
が得られ、ネルンストの理論式より得られる界面電位変
化５８ｍＶ／ｐｉ（（２０°Ｃ）がこの差動増幅回路に
よシ約１．４倍増幅されて得られた。This sensor chip was brought into contact with solutions to be measured consisting of various pH values, and the results of changes in sensor output are shown in FIG. Sensor output is 78mV/pH around pH7
was obtained, and the interfacial potential change of 58 mV/pi ((20°C) obtained from Nernst's theoretical formula was amplified by about 1.4 times by this differential amplifier circuit.
本発明によれば、Ｓｉ基板上に化学ＦＥＴセンサと一諸
にＭＯ８ＦＥＴ素子を形成しでも、そのセンサチップを
被測定溶液につけることが可能となるため、化学ＦＥＴ
センサの信号処理を同一チップ上で出来るようになった
。According to the present invention, even if an MO8FET element is formed together with a chemical FET sensor on a Si substrate, it is possible to immerse the sensor chip in the solution to be measured.
Sensor signal processing can now be performed on the same chip.
第１図は本発明の実施例の化学ＦＥＴセンサとンサとＭ
Ｏ８ｌｉ’ＥＴによって構成された差動増幅回路、第３
図は第２図における回路を使い各測定溶液のｐＨ値値化
化よる出力変化を調べたものである。
ｌ・・・ｐ形Ｓｉ基板、２・・・ｎ＋拡散層、３・・・
ｐ拡散層、４・・・ｐｏｌｙ−８ｉ配線、５・・・酸化
膜、６・・・ｐｏｌｙ−８ｉゲート電極、７・・・Ｓｉ
３Ｎ４膜、８・・・１１図
箋２図
譬３０
０２４６ Ｐ ｌＯ１２
、ＨFIG. 1 shows a chemical FET sensor, sensor and M according to an embodiment of the present invention.
Differential amplifier circuit configured by O8li'ET, third
The figure shows an investigation of the output changes caused by converting the pH value of each measurement solution using the circuit shown in FIG. 2. l...p-type Si substrate, 2...n+ diffusion layer, 3...
p diffusion layer, 4... poly-8i wiring, 5... oxide film, 6... poly-8i gate electrode, 7... Si
3N4 membrane, 8...11 Illustration 2 Illustration 30 0246 P lO12 , H
Claims (1)
サの配線とＭＯＳＦＥＴの配線及びゲート電極とが、半
導体基板表面の酸化膜中に形成されたことを特徴とする
化学ＦＥＴセンサ。 ２、前記酸化膜の表面にＳｉ３Ｎ４等の耐水絶縁膜が形
成されたことを特徴とする特許請求の範囲第１項記載の
化学ＦＥＴセンサ。[Scope of Claims] 1. A chemical FET sensor characterized in that the chemical FIiliT sensor wiring and the MOSFET wiring and gate electrode formed on the same semiconductor substrate are formed in an oxide film on the surface of the semiconductor substrate. 2. The chemical FET sensor according to claim 1, wherein a water-resistant insulating film such as Si3N4 is formed on the surface of the oxide film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58180234A JPS6073352A (en) | 1983-09-30 | 1983-09-30 | Chemical fet sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58180234A JPS6073352A (en) | 1983-09-30 | 1983-09-30 | Chemical fet sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6073352A true JPS6073352A (en) | 1985-04-25 |
Family
ID=16079715
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58180234A Pending JPS6073352A (en) | 1983-09-30 | 1983-09-30 | Chemical fet sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6073352A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0813058A1 (en) * | 1996-06-12 | 1997-12-17 | Siemens Aktiengesellschaft | MOS transistor for biomedical applications |
| CN110940706A (en) * | 2018-09-25 | 2020-03-31 | 英飞凌科技股份有限公司 | Gas sensitive Hall device |
-
1983
- 1983-09-30 JP JP58180234A patent/JPS6073352A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0813058A1 (en) * | 1996-06-12 | 1997-12-17 | Siemens Aktiengesellschaft | MOS transistor for biomedical applications |
| US5801428A (en) * | 1996-06-12 | 1998-09-01 | Siemens Aktiengesellschaft | MOS transistor for biotechnical applications |
| CN110940706A (en) * | 2018-09-25 | 2020-03-31 | 英飞凌科技股份有限公司 | Gas sensitive Hall device |
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