JP2622589B2 - Microelectrode cell for electrochemical measurement and method for producing the same - Google Patents
Microelectrode cell for electrochemical measurement and method for producing the sameInfo
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- JP2622589B2 JP2622589B2 JP63168971A JP16897188A JP2622589B2 JP 2622589 B2 JP2622589 B2 JP 2622589B2 JP 63168971 A JP63168971 A JP 63168971A JP 16897188 A JP16897188 A JP 16897188A JP 2622589 B2 JP2622589 B2 JP 2622589B2
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、作用電極,参照電極,及び対向電極を一体
化して同一基板上に形成した電気化学測定用微小電極セ
ルおよびその製造方法に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microelectrode cell for electrochemical measurement in which a working electrode, a reference electrode, and a counter electrode are integrated and formed on the same substrate, and a method of manufacturing the same. It is.
〔従来の技術〕 従来、微小電極は生体内などの微小領域や微量溶液サ
ンプルの分析に適していることから、様々な有機または
無機材料と組み合わせてセンサなどへの応用が試みられ
ている。微小電極の多くはガラス細管中に白金、金など
の金属線、炭素繊維、金属塩化物等を封入して作製す
る。微小電極の応答挙動は、電極の形状によつて異な
り、応答速度は電極のサイズが減少するに従つて高くな
るため高速電気化学反応の測定を目的として、様々な電
極形状、電極の微細化が検討されている。[Prior Art] Conventionally, since a microelectrode is suitable for analysis of a small region such as a living body or a trace solution sample, application to a sensor or the like in combination with various organic or inorganic materials has been attempted. Most of the microelectrodes are manufactured by encapsulating a metal wire such as platinum or gold, a carbon fiber, a metal chloride, or the like in a thin glass tube. The response behavior of a microelectrode depends on the shape of the electrode, and the response speed increases as the size of the electrode decreases.Therefore, for the purpose of measuring high-speed electrochemical reactions, various electrode shapes and miniaturization of electrodes are required. Are being considered.
また、微小電極を作製する方法として近年、リソグラ
フイ技術の応用が提案されている。この方法ではレジス
トを基板に塗布し、電極パターンを有する画像マスクを
重ね、露光、及び現像した後、金属薄膜を蒸着法等によ
り形成させた後、レジストを剥離させて、基板上に微小
な電極を得るリフトオフ法や、絶縁性基板上に金属薄膜
を作製した後、レジストを塗布し、電極パターンを有す
る画像マスクを重ね、露光、及び現像し、さらに残つた
レジストをマスクにして露出した部分の金属膜をエツチ
ングし、電極パターンを得るエツチング法が知られてい
る。この方法では任意の形状、一定の電極間距離を持つ
微小電極を多量に再現性良く、基板上に作製することが
できるため、近接させた2本の作用電極を作製すればリ
ング・デイスク電極と同様の測定が可能な電極対や、電
気化学素子、センサのベース電極などへ応用が可能であ
る。この微小電極作製法を応用して、これまでにミクロ
な電気化学トランジスタ(例えばJ.Phys.Chem.89,5133
(1985))、くし形白金電極を利用した低分子、または
高分子錯体の電気化学測定(Anal.Chem.,58,601(198
6))等が行われている。さらに、導電性基板上にレジ
ストを塗布し、露光、現像により、レジストに多数の微
細な円形孔をあけて多数のサブミクロンオーダの作用電
極が作製されている(J.Electrochem.Soc.,Vol.133,752
(1986).)。In recent years, application of a lithographic technique has been proposed as a method for manufacturing a microelectrode. In this method, a resist is applied to a substrate, an image mask having an electrode pattern is overlaid, exposed and developed, a metal thin film is formed by a vapor deposition method or the like, and then the resist is peeled off to form a fine electrode on the substrate. After preparing a metal thin film on an insulating substrate, a resist is applied, an image mask having an electrode pattern is overlaid, exposed, and developed, and the remaining resist is used as a mask to expose the exposed portion. An etching method of etching a metal film to obtain an electrode pattern is known. According to this method, a large number of microelectrodes having an arbitrary shape and a constant interelectrode distance can be formed on a substrate with high reproducibility, so that if two working electrodes are brought close to each other, a ring disk electrode can be formed. The present invention can be applied to an electrode pair capable of performing similar measurement, an electrochemical element, a base electrode of a sensor, and the like. By applying this microelectrode fabrication method, microelectrochemical transistors (eg, J. Phys. Chem. 89, 5133)
(1985)), electrochemical measurement of a low-molecular or high-molecular complex using a comb-shaped platinum electrode (Anal. Chem., 58, 601 (198)
6)) and so on. Furthermore, by applying a resist on a conductive substrate, exposing and developing, a large number of fine circular holes are formed in the resist, and a large number of submicron-order working electrodes have been fabricated (J. Electrochem. Soc., Vol. .133,752
(1986). ).
しかしながら従来の電気化学測定用微小電極セルは、
その製造工程に光を用いたリソグラフイ技術を用いてい
るため、0.5μmのギヤプでパターン間を分離するのが
困難になり再現性良く微小な電極対を作製するのは困難
であつた。このため、上記の方法では、全く同じ電極形
状のものを得ることができず、作製に手間がかかり多量
に得ることが困難で、作製した電極間のばらつきも大き
いため、定量的なデータが必要な場合には前もつて、電
極を検定しておく必要があり、多大な測定時間を必要と
した。また、この測定により電極が汚染、腐食される等
の理由により検定することができない場合には、定量的
なデータを得ることが非常に困難であつた。However, conventional microelectrode cells for electrochemical measurements are:
Since a lithographic technique using light is used in the manufacturing process, it is difficult to separate the patterns with a gap of 0.5 μm, and it is difficult to produce a fine electrode pair with good reproducibility. For this reason, in the above-mentioned method, it is impossible to obtain a completely identical electrode shape, it is troublesome to manufacture, it is difficult to obtain a large amount, and there is a large variation between the manufactured electrodes, so quantitative data is required. In such cases, it was necessary to test the electrodes beforehand, which required a great deal of measurement time. In addition, when it is not possible to carry out the test due to contamination or corrosion of the electrode by this measurement, it has been very difficult to obtain quantitative data.
この欠点を解決する方法として、基板上に金属、絶縁
体、金属を順に積層した後、その端面を出して電極に用
いる方法が提案されている。この方法では緻密な絶縁性
薄膜を用いることにより、電極間隔を狭めて挟めること
が可能であるが、大面積を得ることができないため電流
値が低くなる結果となつた。さらに、薄膜の端面を使用
するため、バンド電極以外の任意の形状を有する電極が
得られないなどの欠点があり、解決するには至つていな
い。As a method for solving this drawback, a method has been proposed in which a metal, an insulator, and a metal are sequentially laminated on a substrate, and the end face is exposed and used as an electrode. In this method, by using a dense insulating thin film, it is possible to narrow the gap between the electrodes. However, since a large area cannot be obtained, the current value is reduced. Furthermore, since the end face of the thin film is used, there is a disadvantage that an electrode having an arbitrary shape other than the band electrode cannot be obtained, and the solution has not been solved.
本発明は上記の欠点を解決するため、絶縁膜を介した
段差による立体的間隔により分離した第1と第2の薄膜
電極を少なくとも備え、各薄膜電極表面の全面またはそ
の一部を露出させている。In order to solve the above-mentioned drawbacks, the present invention comprises at least first and second thin-film electrodes separated by a three-dimensional space due to a step via an insulating film, and exposes the entire surface of each thin-film electrode or a part thereof. I have.
また、絶縁性基板上にパターン形状を有する単数また
は平面的間隙で分離された複数の第1の導電性薄膜を形
成する工程と、この第1の導電性薄膜を含めた絶縁性基
板上に絶縁膜を形成する工程と、この絶縁膜上にパター
ン形状を有する単数または平面間隙で分離された複数の
第2の導電性薄膜を形成する工程と、この第2の導電性
薄膜をマスクにして前記絶縁膜をエツチングし、前記第
1の導電性薄膜を露出させる工程とを有している。A step of forming a single or a plurality of first conductive thin films having a pattern shape on the insulating substrate and separated by a planar gap, and forming an insulating film on the insulating substrate including the first conductive thin film; A step of forming a film, a step of forming a single or a plurality of second conductive thin films separated by a planar gap having a pattern shape on the insulating film, and using the second conductive thin film as a mask, Etching the insulating film to expose the first conductive thin film.
立体的間隙は各薄膜電極間を微小な間隙で分離する。 The three-dimensional gap separates each of the thin film electrodes with a minute gap.
以下、本発明の実施例を図に従つて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
実施例1 第1図は本発明に係る第1の実施例を示した電気化学
測定用微小電極セルの概観図である。図において、1は
基板となるシリコンウエハ、2はシリコンウエハ1上に
形成した酸化膜、3は参照電極、4は二酸化シリコン
膜、5は二酸化シリコン膜4上に形成された作用電極、
6は同じく二酸化シリコン膜4上に形成された対向電極
である。ここで作用電極5と対向電極6はくし形電極を
形成している。Example 1 FIG. 1 is a schematic view of a microelectrode cell for electrochemical measurement showing a first example according to the present invention. In the figure, 1 is a silicon wafer serving as a substrate, 2 is an oxide film formed on the silicon wafer 1, 3 is a reference electrode, 4 is a silicon dioxide film, 5 is a working electrode formed on the silicon dioxide film 4,
Reference numeral 6 is a counter electrode formed on the silicon dioxide film 4. Here, the working electrode 5 and the counter electrode 6 form a comb-shaped electrode.
また、第2図(a)〜(g)は第1図における微小電
極セルの製造方法を示した断面図である。図において、
7は二酸化シリコン層、8はレジストである。なお、第
1図には説明の便宜のため二酸化シリコン層7を省略し
てある。2 (a) to 2 (g) are cross-sectional views showing a method for manufacturing the microelectrode cell in FIG. In the figure,
7 is a silicon dioxide layer and 8 is a resist. In FIG. 1, the silicon dioxide layer 7 is omitted for convenience of explanation.
次に、第2図(a)〜(g)に従つて製造方法を説明
する。まず、1μmの酸化膜付きシリコンウエハ(大阪
チタニウム社製)(第2図(a))を、スパツタ装置
(アネルバ製、SPF332H)内の所定位置に取付け、クロ
ム,銀を選択的にスパツタデポし、参照電極3を形成す
る(同図(b))。次に、同一のスパツタ装置を用いて
二酸化シリコン膜4を形成する(同図(c))。このと
きのスパツタ装置の条件は、アルゴンガス雰囲気,圧力
10-2Torrにおいて、クロム:50W,10秒、銀:70W,1分、二
酸化シリコン膜:50W,5分のスパツタを行ない、クロム、
銀:150nm、二酸化シリコン膜:100nmの膜厚とする。次
に、この二酸化シリコン膜4上に電子線レジスト(φ−
MAC、ダイキン工業社製)を1.0μmの厚みに塗布する。
そして、このレジストを塗布したシリコンウエハをオー
ブン中にいれ180℃、60分の上限でベークする。その
後、電子線露光装置(日本電子:JSM−840)に入れ、電
子線の加速電圧:10kV、露光量:5μC/cm2の条件でピツチ
3.5μm、ギヤツプ0.5μmの、長さ1.0mm、のかみ合つ
たくし形電極パターンを露光する。次に、所定の現像液
で現像後クロム、白金膜をスパツタ装置(アネルバ製:S
PF332H)により約200nmの厚みに形成し、レジストを溶
剤により除去して作用電極5と対向電極6にあたるかみ
合つたくし形電極パターンを形成する。その後、この基
板上にフオトレジスト(シツプレー社製AZ1400−27)を
1μmの厚みに塗布し、位置合わせを行つてくし形電極
のリード、パツド部分、対向電極パターンを密着露光す
る。そして、現像後、再びクロム、白金のスパツタを行
い、レジストをメチルエチルケトン中ではくりしてリー
ド、パツドを持つくし形電極、対向電極パターンを形成
する(同図(d))。次に、この基板を再びスパツタ装
置(アネルバ製 SPF332H)中に入れ、基板全面を100nm
の二酸化シリコン層7を形成する(同図(e))。次
に、この基板上にフオトレジスト8(シプレー社製 AZ
1400−27)を1μmの厚みに塗布し、クロムマスクを用
いてかみ合つたくし形電極部分(1mm×0.25mm)、対向
電極、パツド部分のみを露光、現像し、その部分を露出
する(同図(f))。次に、この基板を反応性イオンエ
ツチング装置(アネルバ製、DEM−451)中にいれ、C2F6
ガス、流量:25SCCM、圧力:0.25Pa、150Wの条件でレジス
タパターンをマスクして5分間、二酸化シリコン膜4,及
び二酸化シリコン層7のエツチングを行つて下部に形成
した参照電極3を露出する。これにより、参照電極3、
作用電極5、及び対向電極6の間が非常に小さいかみ合
つたくし形電気化学測定用微小電極セルが得られる(同
図(g))。Next, the manufacturing method will be described with reference to FIGS. First, a 1 μm silicon wafer with an oxide film (manufactured by Osaka Titanium Co., Ltd.) (FIG. 2 (a)) is attached to a predetermined position in a sputter device (manufactured by Anelva, SPF332H), and chromium and silver are selectively sputter deposited. A reference electrode 3 is formed (FIG. 2B). Next, a silicon dioxide film 4 is formed using the same sputter device (FIG. 3C). At this time, the conditions of the spatter device are as follows: argon gas atmosphere, pressure
At 10 -2 Torr, chromium: 50 W, 10 seconds, silver: 70 W, 1 minute, silicon dioxide film: 50 W, 5 minutes
Silver: 150 nm, silicon dioxide film: 100 nm. Next, an electron beam resist (φ-
MAC, manufactured by Daikin Industries, Ltd.) to a thickness of 1.0 μm.
Then, the silicon wafer coated with the resist is placed in an oven and baked at 180 ° C. for 60 minutes. After that, it was put into an electron beam exposure apparatus (JEOL: JSM-840), and the pitch was adjusted under the conditions of an electron beam acceleration voltage of 10 kV and an exposure amount of 5 μC / cm 2.
A 3.5 μm, 0.5 μm gap, 1.0 mm long, interdigitated comb electrode pattern is exposed. Next, after developing with a predetermined developing solution, the chromium and platinum films are spread with a sputter device (Anelva: S
PF332H) is formed to a thickness of about 200 nm, and the resist is removed with a solvent to form a comb-shaped electrode pattern that meshes with the working electrode 5 and the counter electrode 6. Thereafter, a photoresist (AZ1400-27, manufactured by Shipley Co., Ltd.) is applied on the substrate to a thickness of 1 μm, and alignment is performed, and the leads, pad portions, and counter electrode pattern of the interdigital electrode are exposed in close contact. Then, after development, spattering of chromium and platinum is performed again, and the resist is stripped in methyl ethyl ketone to form a comb-shaped electrode having leads and pads and a counter electrode pattern (FIG. 4D). Next, the substrate is put again in a sputter device (Anelva SPF332H), and the entire surface of the substrate is 100 nm.
The silicon dioxide layer 7 is formed as shown in FIG. Next, a photoresist 8 (AZP, manufactured by Shipley Co., Ltd.) is placed on the substrate.
1400-27) is applied to a thickness of 1 µm, and only the interdigitated comb-shaped electrode portion (1 mm x 0.25 mm), the counter electrode, and the pad portion are exposed and developed using a chrome mask, and the portion is exposed. Figure (f). Next, this substrate was placed in a reactive ion etching apparatus (DEM-451, manufactured by Anelva), and C 2 F 6
The resist pattern is masked under the conditions of gas, flow rate: 25 SCCM, pressure: 0.25 Pa, 150 W, and the silicon dioxide film 4 and the silicon dioxide layer 7 are etched for 5 minutes to expose the reference electrode 3 formed below. Thereby, the reference electrode 3,
A very small interdigitated microelectrode cell for electrochemical measurement is obtained between the working electrode 5 and the counter electrode 6 (FIG. 9 (g)).
この電気化学測定用微小電極セルを0.1mmol/のフエ
リシアン化鉄を溶かした40℃の水溶液に浸し、パツドを
それぞれポテンシオスタツトにリード線を介して接続
し、一方のくし形電極(作用電極5)を−0.3Vから0.5V
まで10mV/secで電位走査し、他方のくし形電極(対向電
極6)を対向電極に用いてサイクリツクボルタングラム
測定を行うとフエリシアン化鉄の酸化還元に伴う可逆的
なピークが得られ、高抵抗溶液中でも電気化学測定が可
能であつた。This microelectrode cell for electrochemical measurement is immersed in an aqueous solution of 0.1 mmol / iron ferricyanide at 40 ° C., and each pad is connected to a potentiostat via a lead wire. ) From -0.3V to 0.5V
When the potential was scanned at 10 mV / sec and cyclic voltammogram measurement was performed using the other comb-shaped electrode (counter electrode 6) as the counter electrode, a reversible peak accompanying the redox of iron ferricyanide was obtained. Electrochemical measurement was possible even in the resistance solution.
また、ポリエチレンオキサイド(アルドリツチ製,重
量平均分子量:600,00)0.9gとトリフルオロメタンスル
ホン酸リチウム0.2g,フエロセン1mgをアセトニトリルと
メタノール9対1の混合溶媒100mlに溶解させ、溶液を
この微小電極セル上にたらして溶媒を乾燥させ高分子フ
イルムを得た。Also, 0.9 g of polyethylene oxide (manufactured by Aldrich, weight average molecular weight: 600,00), 0.2 g of lithium trifluoromethanesulfonate, and 1 mg of ferrocene are dissolved in 100 ml of a mixed solvent of acetonitrile and methanol 9: 1, and the solution is placed in this microelectrode cell. Then, the solvent was dried and a polymer film was obtained.
さらに、各電極のパツドをポテンシオスタツトに接続
し、一方のくし形電極電位を−0.3〜0.7Vまで100mV/sec
で走査するとフエロセンの酸化還元反応にともなうピー
クが観測された。酸化ピークと還元ピークのずれは80mV
で可逆的な酸化還元反応の理論値(63mV)に近く、固体
電解質中でも定量的な電気化学測定を行うことができ
た。In addition, the pad of each electrode is connected to a potentiostat, and the potential of one of the electrodes is 100mV / sec from -0.3 to 0.7V.
Scanning, a peak associated with the oxidation-reduction reaction of ferrocene was observed. The difference between the oxidation peak and the reduction peak is 80mV
The value was close to the theoretical value of the reversible redox reaction (63 mV), and quantitative electrochemical measurements could be performed even in solid electrolytes.
実施例2 第3図は本発明に係る第2の実施例を示した電気化学
測定用微小電極セルの概観図である。図において、11は
石英基板、12は二酸化シリコン膜、13は作用電極、14は
参照電極、15は対向電極、16は作用電極である。ここで
作用電極13及び16はくし形電極を形成している。Example 2 FIG. 3 is a schematic view of a microelectrode cell for electrochemical measurements showing a second example according to the present invention. In the figure, 11 is a quartz substrate, 12 is a silicon dioxide film, 13 is a working electrode, 14 is a reference electrode, 15 is a counter electrode, and 16 is a working electrode. Here, the working electrodes 13 and 16 form comb electrodes.
次に、第2の実施例の製造方法を説明する。まず、厚
み0.3mmの石英基板を、スパツタ装置(アネルバ製:SPF3
32H)内の所定位置に取付け、クロム,白金を選択的に
スパツタデポし、作用電極16を形成する。次に同一のス
パツタ装置を用いて二酸化シリコン膜12を形成する。こ
のときのスパツタ装置の条件は、アルゴンガス雰囲気,
圧力10-2Torrにおいて、クロム:50W,10秒、白金:70W,1
分、二酸化シリコン膜:50W,3分のスパツタを行ない、ク
ロム、白金:100nm、二酸化シリコン膜100nmとする。次
に、この二酸化シリコン膜12上にフオトレジスト(シツ
プレー社製 AZ1400−27)を1μmの厚みに塗布する。
このレジスト塗布石英基板をオーブン中にいれ80℃、30
分の条件でベークする。その後、ホトマスクを用いて、
マスクアライナ(キヤノン製)により電極パターンを20
秒間密着露光する。パターンはピツチ5μm ギヤツプ
2μm全体のサイズ2mm×0.25mmのくし形電極、及び参
照電極、対向電極及びそれらのリード、パツドとした。
露光した石英基板11は、レジスト現像液(シプレー社
製、AZ デベロパー)中で、20℃、120秒間現像を行
い、水洗、乾燥してマスクパターンをレジストに転写す
る。現像後、この基板を再びスパツタ装置中に入れ、ク
ロム:50W、5秒、白金:70W、2分スパツタを行い、200n
mの膜を形成した後、メチルエチルケトン中でレジスト
を剥離し、作用電極13、参照電極14、及び対向電極15の
電極パターンを形成する。次に、この基板を再びスパツ
タ装置中にいれ、二酸化シリコン膜を150nmの厚みに形
成する。その後、この基板上にフオトレジスト(シプレ
ー社製 AZ1400−27)を1μmの厚みに塗布し、クロム
マスクを用いてくし形電極部分(2mm×0.25mm)、参照
電極、対向電極、パツド部分のみを露光、現像する。次
に、この基板を反応性イオンエツチング装置(アネルバ
製、DEM−451)中にいれ、C2F6ガス、流量:25SCCM、圧
力:0.25Pa、150Wの条件でレジストパターンをマスクに
して2分間、二酸化シリコン12のエツチングを行つて下
部電極を露出する。また、参照電極先端部分には参照物
質として60℃のメツキ液に10秒間浸漬して銀をメツキす
る。Next, a manufacturing method of the second embodiment will be described. First, a quartz substrate with a thickness of 0.3 mm was placed on a spatter device (Anelva: SPF3
32H), and the working electrode 16 is formed by selectively depositing chromium and platinum on the sputter. Next, a silicon dioxide film 12 is formed using the same sputter device. At this time, the conditions of the spatter device were an argon gas atmosphere,
At a pressure of 10 -2 Torr, chromium: 50 W, 10 seconds, platinum: 70 W, 1
Sputter for 50 minutes, silicon dioxide film: 3 minutes, chromium and platinum: 100 nm, silicon dioxide film: 100 nm. Next, a photoresist (AZ1400-27 manufactured by Shipley Co.) is applied on the silicon dioxide film 12 to a thickness of 1 μm.
Put the resist coated quartz substrate in an oven at 80 ° C, 30
Bake for minutes. Then, using a photomask,
20 electrode patterns using a mask aligner (Canon)
Contact exposure is performed for 2 seconds. The pattern was a comb-shaped electrode having a size of 2 mm × 0.25 mm, a reference electrode, a counter electrode, and their leads and pads, each having a pitch of 5 μm and a gap of 2 μm.
The exposed quartz substrate 11 is developed in a resist developing solution (AZ Developer, AZ Developer) at 20 ° C. for 120 seconds, washed with water and dried to transfer the mask pattern to the resist. After the development, the substrate was put into a spatter again, and chromium: 50 W, 5 seconds, platinum: 70 W, spattered for 2 minutes, and 200 n
After forming the film of m, the resist is stripped in methyl ethyl ketone to form electrode patterns of the working electrode 13, the reference electrode 14, and the counter electrode 15. Next, the substrate is put again in the sputter device, and a silicon dioxide film is formed to a thickness of 150 nm. Thereafter, a photoresist (AZ1400-27 manufactured by Shipley Co., Ltd.) is applied to this substrate to a thickness of 1 μm, and only a comb-shaped electrode portion (2 mm × 0.25 mm), a reference electrode, a counter electrode, and a pad portion are applied using a chrome mask. Exposure and development. Next, the substrate was placed in a reactive ion etching apparatus (DEM-451, manufactured by Anelva), and C 2 F 6 gas, flow rate: 25 SCCM, pressure: 0.25 Pa, 150 W, and the resist pattern was used as a mask for 2 minutes. Then, the lower electrode is exposed by etching the silicon dioxide 12. The tip of the reference electrode is immersed in a plating solution at 60 ° C. as a reference substance for 10 seconds to paint silver.
この電気化学測定用微小電極セルを0.1mmol/のフエ
ロセン、0.1mol/の支持電解質(テトラエチルアンモ
ニウム・パークロレート)を溶かしたアセトニトリル溶
液に浸し、パツドをそれぞれバイポテンシオスタツトに
リード線を介して接続し、下層電極を−0.3Vから0.5Vま
で100mV/secで電位走査を上層のくし形電極を−0.3Vに
固定して電流値の測定を行うと、前者はフエロセンの酸
化反応、後者は還元反応に基ずく限界電流が観測され
た。両者の電流値の大きさの絶対値を比較すると捕捉率
98%が得られた。また、一方のくし形電極の電位−0.3V
に固定し、もう一方のくし形電極の電位を0.7Vの電位を
印加すると、電圧印加後90msecで定常状態に達し応答が
速いことが分かつた。さらに、この電気化学測定用微小
電極セルを真空中に入れ、10mTorrの水蒸気を導入した
後、上部、下部くし形電極の間に1Vの電圧を印可すると
5μAの電流が得られ、気相中の分子の電気化学反応を
測定できることが分かつた。This microelectrode cell for electrochemical measurement is immersed in an acetonitrile solution in which 0.1 mmol / of ferrocene and 0.1 mol / of a supporting electrolyte (tetraethylammonium perchlorate) are dissolved, and each pad is connected to a bipotentiostat via a lead wire. When the lower electrode is fixed at -0.3 V and the electric potential is scanned from -0.3 V to 0.5 V at 100 mV / sec and the upper comb electrode is fixed at -0.3 V, the former is the oxidation reaction of ferrocene and the latter is the reduction. A limiting current based on the reaction was observed. Comparing the absolute value of the magnitude of both current values, the trapping rate
98% were obtained. Also, the potential of one comb-shaped electrode -0.3V
When the potential of the other comb electrode was applied to a potential of 0.7 V, the steady state was reached 90 msec after the application of the voltage, and the response was quick. Further, after placing the microelectrode cell for electrochemical measurement in a vacuum and introducing 10 mTorr of water vapor, when a voltage of 1 V was applied between the upper and lower comb-shaped electrodes, a current of 5 μA was obtained, and a current of 5 μA was obtained. It has been found that electrochemical reactions of molecules can be measured.
実施例3 第3の実施例として電気化学測定用微小電極セルの製
造方法を説明する。厚み0.3mmの石英基板上にクロム,
白金,及び二酸化シリコン膜をスパツタデポするまでは
実施例2と同一である。次に、この二酸化シリコン膜上
にフオトレジスト(シツプレー社製 AZ−1400−27)を
1μmの厚みに塗布する。このレジスト塗布石英基板を
オーブン中にいれ80℃、30分の条件でベークする。その
後、クロムマスクを用いて、マスクアライナー(キヤノ
ン製)により20秒間密着露光する。パターンは幅2μm
ギヤツプ2μm全体のサイズ1×1mmの格子電極、及び
参照電極、対向電極及びそれらのリード、パツドとし
た。露光した石英基板は、レジスト現像液(シプレー社
製、AZ デベロパー)中で、20℃、120秒間現像を行
い、水洗、乾燥してマスクパターンをレジストに転写す
る。現像後、該基板は再びスパツタ装置中に入れ、クロ
ム:50W、5秒、白金:70W、2分スパツタを行い、200nm
の膜を形成した後、メチルエチルケトン中でレジストを
剥離し、電極パターンを形成する。次にこの基板を再び
スパツタ装置中にいれ、二酸化シリコン膜を150nmの厚
みに形成する。その後、この基板上にフオトレジスト
(シプレー社製 AZ1400−27)を1μmの厚みに塗布
し、クロムマスクを用いて格子電極部分、参照電極、対
向電極、パツド部分のみを露光、現像する。次に、該基
板は反応性イオンエツチング装置(アネルバ製、DEM−4
51)中にいれ、C2F6ガス、流量:25SCCM、圧力:0.25Pa、
150Wの条件でレジストパターンをマスクにして2分間、
二酸化シリコンのエツチングを行つて下部電極を露出す
る。また、参照電極先端部分には参照物質として60℃の
メツキ液に10秒間浸漬して銀をメツキする。Example 3 As a third example, a method for manufacturing a microelectrode cell for electrochemical measurements will be described. Chrome on a 0.3mm thick quartz substrate
It is the same as the second embodiment until the platinum and silicon dioxide films are sputter deposited. Next, a photoresist (AZ-1400-27 manufactured by Shipley Co.) is applied on the silicon dioxide film to a thickness of 1 μm. The resist-coated quartz substrate is placed in an oven and baked at 80 ° C. for 30 minutes. Thereafter, contact exposure is performed for 20 seconds by a mask aligner (manufactured by Canon Inc.) using a chrome mask. The pattern is 2 μm wide
A 1 μm × 1 mm grid electrode, a reference electrode, a counter electrode and their leads and pads were formed over the entire gap of 2 μm. The exposed quartz substrate is developed in a resist developer (AZ Developer, Shipley) at 20 ° C. for 120 seconds, washed with water and dried to transfer the mask pattern to the resist. After the development, the substrate was put again in a spatter device, and chromium: 50 W, 5 seconds, platinum: 70 W, spattered for 2 minutes, and 200 nm
After the formation of the film, the resist is stripped in methyl ethyl ketone to form an electrode pattern. Next, this substrate is put again in the sputter device, and a silicon dioxide film is formed to a thickness of 150 nm. Thereafter, a photoresist (AZ1400-27 manufactured by Shipley Co., Ltd.) is applied on this substrate to a thickness of 1 μm, and only the grid electrode portion, the reference electrode, the counter electrode, and the pad portion are exposed and developed using a chromium mask. Next, the substrate was subjected to a reactive ion etching apparatus (DEM-4, manufactured by Anelva).
51) Inside, C 2 F 6 gas, flow rate: 25SCCM, pressure: 0.25Pa,
Under the condition of 150W, using the resist pattern as a mask for 2 minutes,
Etching of silicon dioxide is performed to expose the lower electrode. The tip of the reference electrode is immersed in a plating solution at 60 ° C. as a reference substance for 10 seconds to paint silver.
この電気化学測定用微小電極セルを0.1mmol/のフエ
ロセン、0.1mol/の支持電解質(テトラエチルアンモ
ニウム・パークロレート)を溶かしたアセトニトリル溶
液に浸し、パツドをそれぞれバイポテンシオスタツトに
リード線を介して接続し、下層電極を−0.3Vから0.5Vま
で100mV/secで電位走査を上層のくし形電極を−0.3Vに
固定して電流値の測定を行うと、前者はフエロセンの酸
化反応、後者は還元反応に基ずく限界電流が観測され
た。両者の電流値の大きさの絶対値を比較すると捕捉
率、99%以上が得られ、下部電極で酸化されたフエロセ
ン分子は殆ど上部電極で捕捉されていることが分かつ
た。This microelectrode cell for electrochemical measurement is immersed in an acetonitrile solution in which 0.1 mmol / of ferrocene and 0.1 mol / of a supporting electrolyte (tetraethylammonium perchlorate) are dissolved, and each pad is connected to a bipotentiostat via a lead wire. When the lower electrode is fixed at -0.3 V and the electric potential is scanned from -0.3 V to 0.5 V at 100 mV / sec and the upper comb electrode is fixed at -0.3 V, the former is the oxidation reaction of ferrocene and the latter is the reduction. A limiting current based on the reaction was observed. Comparing the absolute values of the magnitudes of the two current values, a trapping rate of 99% or more was obtained, and it was found that most of the oxidized ferrocene molecules at the lower electrode were trapped at the upper electrode.
また、ポリエチレンオキサイト(アルドリツチ製、重
量平均分子量:600,000)0.9gをトリフルオロメタンスル
ホン酸:0.02g、フエロセン、2mgをアセトニトリル:メ
タノール9:1の混合溶液に溶解させ、溶液をこの微小電
極セル上にたらして溶媒を乾燥させ高分子フイルムを得
た。その後、電極をバイポテンシオスタツトに接続し、
下部作用電極の電位を−0.3Vから0.5Vまで10mV/secで走
査し、上部電極を−0.3Vに固定して、電流値の測定を行
い97.5%の高い捕捉率が得られた。Also, 0.9 g of polyethylene oxide (manufactured by Aldrich, weight average molecular weight: 600,000) was dissolved in a mixed solution of 0.02 g of trifluoromethanesulfonic acid, 0.02 g of ferrocene, and 9 mg of acetonitrile: methanol, and the solution was placed on the microelectrode cell. After drying, the solvent was dried to obtain a polymer film. Then connect the electrodes to the bipotentiostat,
The potential of the lower working electrode was scanned from -0.3 V to 0.5 V at 10 mV / sec, the upper electrode was fixed at -0.3 V, and the current value was measured. As a result, a high capture rate of 97.5% was obtained.
このように本実施例における電気化学測定用微小電極
セルは、リソグラフイー技術により得られた平面的間隙
と二酸化シリコン膜を介した段差による立体的間隙とに
よつて各電極が分離されているため、微小なギヤツプで
再現性良く各電極を分離することができる。このため、
各微小電極セル毎の特性が安定し、従来のような検定作
業が不用となり、測定時間の短縮を図ることができる。As described above, in the microelectrode cell for electrochemical measurement according to the present embodiment, each electrode is separated by the planar gap obtained by the lithographic technique and the three-dimensional gap due to the step through the silicon dioxide film. Each electrode can be separated with high reproducibility using a small gap. For this reason,
The characteristics of each microelectrode cell are stabilized, and the conventional inspection work becomes unnecessary, and the measurement time can be reduced.
また、各薄膜電極間のギヤツプを狭くすることが可能
となるため、電気化学測定の高速化,高感度化が図れる
などの効果を有する。In addition, since the gap between the thin film electrodes can be reduced, there is an effect that the speed of electrochemical measurement and the sensitivity can be increased.
なお上記実施例において絶縁性基板として酸化膜つき
シリコン基板及び石英基板を用いて説明したが、酸化ア
ルミニウム基板、ガラス基板、プラスチツク基板などを
挙げることができる。また、電極用の金属としては金、
クロム、チタン、ステンレスなどを挙げることができ
る。また、電極用の半導体としてはp及びn型シリコ
ン、p及びn型ゲルマニウム、硫化カドミウム、二酸化
チタン、酸化亜鉛、ガリウムリン、ガリウム砒素、イン
ジウムリン、カドミウムセレン、カドミウムテルル、二
硫化モリブデン、セレン化タングステン、二酸化銅、酸
化スズ、酸化イノジウム、イノジウムスズ酸化物などを
挙げることができる。また、半金属としては導電性ガー
ボンを挙げることができる。絶縁膜としては酸化シリコ
ン、窒化シリコン、シリコーン樹脂、ポリイミド及びそ
の誘導体、エポキシ樹脂、高分子熱硬化物などを挙げる
ことができる。参照電極上の参照物質としては、塩化
銀、ポリビニルフエロセン等を挙げることができる。In the above embodiments, a silicon substrate with an oxide film and a quartz substrate have been described as insulating substrates, but an aluminum oxide substrate, a glass substrate, a plastic substrate, or the like can be used. In addition, as a metal for the electrode, gold,
Chromium, titanium, stainless steel, and the like can be given. Semiconductors for electrodes include p and n type silicon, p and n type germanium, cadmium sulfide, titanium dioxide, zinc oxide, gallium phosphide, gallium arsenide, indium phosphide, cadmium selenium, cadmium telluride, molybdenum disulfide, selenide Examples thereof include tungsten, copper dioxide, tin oxide, indium oxide, and indium tin oxide. In addition, examples of the semimetal include conductive garbon. Examples of the insulating film include silicon oxide, silicon nitride, silicone resin, polyimide and derivatives thereof, epoxy resin, and thermosetting polymer. Examples of the reference substance on the reference electrode include silver chloride, polyvinyl ferrocene, and the like.
また、上記実施例において微小電極セルの製作にスパ
ツタを用いたが、蒸着、CVD、または塗布法により金
属、半導体、または半金属の導電性薄膜、絶縁膜、導電
性薄膜を形成してもよい。Further, in the above embodiment, a spatter was used for manufacturing the microelectrode cell, but a metal, semiconductor, or semimetal conductive thin film, insulating film, or conductive thin film may be formed by vapor deposition, CVD, or a coating method. .
以上説明のように本発明は、絶縁膜を介した段差によ
る立体的間隔により分離した第1と第2の薄膜電極を用
いるようにしているため、微小な間隙で再現性良く薄膜
電極間を分離することができる。このため、各電気化学
測定用微小電極セル毎の特性が安定し、従来のような検
定作業が不用となり、測定時間の短縮を図ることができ
る。As described above, the present invention uses the first and second thin-film electrodes separated by the three-dimensional space due to the step between the insulating films, so that the thin-film electrodes can be separated with good reproducibility at a minute gap. can do. For this reason, the characteristics of each electrochemical measurement microelectrode cell are stabilized, and the conventional inspection work is unnecessary, and the measurement time can be shortened.
また、各薄膜電極間の間隙を微小にすることが可能と
なるため、電気化学測定の高速化,高感度化が図れる。
さらに、電解質を含まない溶液,固体,気体などの高抵
抗の試料中で電気の化学的な測定が可能になるなどの効
果を有する。Further, since the gap between the thin film electrodes can be reduced, the speed and sensitivity of the electrochemical measurement can be increased.
In addition, the present invention has an effect that an electrochemical measurement of electricity can be performed in a high-resistance sample such as a solution, a solid, and a gas containing no electrolyte.
【図面の簡単な説明】 第1図は本発明に係る第1の実施例を示した電気化学測
定用微小電極セルの概観図、第2図は第1図における電
気化学測定用微小電極セルの製造方法を示した断面図、
第3図は本発明に係る第2の実施例を示した電気化学測
定用微小電極セルの概観図である。 1……シリコンウエハ、2……酸化膜、3,14……参照電
極、4,12……二酸化シリコン膜、5,13,16……作用電
極、6,15……対向電極、7……二酸化シリコン層、8…
…レジスト、11……石英基板。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a microelectrode cell for electrochemical measurement showing a first embodiment according to the present invention, and FIG. 2 is a view of the microelectrode cell for electrochemical measurement in FIG. Sectional view showing a manufacturing method,
FIG. 3 is a schematic view of a microelectrode cell for electrochemical measurement showing a second embodiment according to the present invention. 1 ... silicon wafer, 2 ... oxide film, 3, 14 ... reference electrode, 4, 12 ... silicon dioxide film, 5, 13, 16 ... working electrode, 6, 15 ... counter electrode, 7 ... Silicon dioxide layer, 8 ...
... resist, 11 ... quartz substrate.
Claims (2)
を有する微小電極セルにおいて、 前記絶縁性基板主表面に形成された第1の薄膜電極と、 前記第1の薄膜電極の少なくとも一部は露出するように
前記第1の薄膜電極を含めた絶縁性基板上に形成された
絶縁膜と、 前記絶縁膜により前記第1の薄膜電極と絶縁分離してこ
の絶縁膜上に形成された第2の薄膜電極と を少なくとも備え、 各薄膜電極表面の全面またはその一部を露出させたこと
を特徴とする電気化学測定用微小電極セル。1. A microelectrode cell having a plurality of thin film electrodes formed on an insulating substrate, wherein: a first thin film electrode formed on a main surface of the insulating substrate; and at least one of the first thin film electrodes. An insulating film formed on an insulating substrate including the first thin film electrode so as to be exposed; and an insulating film formed on the insulating film by being insulated and separated from the first thin film electrode by the insulating film. A microelectrode cell for electrochemical measurement, comprising at least a second thin film electrode and exposing the entire surface or a part of the surface of each thin film electrode.
または平面的間隙で分離された複数の第1の導電性薄膜
を形成する工程と、 この第1の導電性薄膜を含めた絶縁性基板上に絶縁膜を
形成する工程と、 この絶縁膜上にパターン形状を有する単数または平面的
間隙で分離された複数の第2の導電性薄膜を形成する工
程と、 この第2の導電性薄膜をマスクにして前記絶縁膜をエツ
チングし、前記第1の導電性薄膜を露出させる工程とを
有することを特徴とする電気化学測定用微小電極セルの
製造方法。2. A step of forming a single or a plurality of first conductive thin films having a pattern shape and separated by a planar gap on an insulating substrate, and an insulating substrate including the first conductive thin film. A step of forming an insulating film thereon; a step of forming a single or a plurality of second conductive thin films separated by a planar gap having a pattern shape on the insulating film; Etching the insulating film using a mask to expose the first conductive thin film.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63168971A JP2622589B2 (en) | 1988-07-08 | 1988-07-08 | Microelectrode cell for electrochemical measurement and method for producing the same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63168971A JP2622589B2 (en) | 1988-07-08 | 1988-07-08 | Microelectrode cell for electrochemical measurement and method for producing the same |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0219757A JPH0219757A (en) | 1990-01-23 |
JP2622589B2 true JP2622589B2 (en) | 1997-06-18 |
Family
ID=15877963
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JP63168971A Expired - Lifetime JP2622589B2 (en) | 1988-07-08 | 1988-07-08 | Microelectrode cell for electrochemical measurement and method for producing the same |
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JPH02140655A (en) * | 1988-11-21 | 1990-05-30 | Nippon Telegr & Teleph Corp <Ntt> | Electrochemical detector and production thereof |
JP3244249B2 (en) * | 1995-03-20 | 2002-01-07 | 日本電信電話株式会社 | Electrode for sensor |
WO2001033207A1 (en) * | 1999-11-04 | 2001-05-10 | Advanced Sensor Technologies, Inc. | Microscopic multi-site sensor array with integrated control and analysis circuitry |
US7547381B2 (en) * | 2003-09-26 | 2009-06-16 | Agency For Science, Technology And Research And National University Of Singapore | Sensor array integrated electrochemical chip, method of forming same, and electrode coating |
TWI781587B (en) * | 2021-04-14 | 2022-10-21 | 財團法人金屬工業研究發展中心 | Sensing electrode |
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1988
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