METHOD FOR MANUFACTURING A WORKING ELECTRODE OF ELECTROCHEMICAL SENSOR AND PRODUCT THEREOF

Abstract

A method for manufacturing a working electrode of electrochemical sensor comprises the steps of: step S1, providing a substrate; step S2, forming a wavy pattern on the substrate; and step S3, disposing a conductive substance on the wavy pattern. A working electrode of electrochemical sensor is also disclosed.

Claims

1. A method for manufacturing a working electrode of electrochemical sensor, comprising the steps of: step S1, providing a substrate; step S2, forming a wavy pattern on the substrate; and step S3, disposing a conductive substance on the wavy pattern.

2. The method for manufacturing a working electrode of electrochemical sensor as recited in claim 1, further comprising a step of forming a protective layer on one side of the substrate.

3. The method for manufacturing a working electrode of electrochemical sensor as recited in claim 2, further comprising a step of forming a plurality of openings on the protective layer using lithography and dry etching.

4. The method for manufacturing a working electrode of electrochemical sensor as recited in claim 3, further comprising a step of forming a plurality of grooves with semicircular shaped having acute angles on the substrate through the plurality of openings using isotropic etching, or forming a plurality of grooves with inverted triangular having acute angles on the substrate through the plurality of openings using anisotropic etching.

5. The method for manufacturing a working electrode of electrochemical sensor as recited in claim 4, further comprising the steps of: removing the protective layer; and forming the acute angles into rounded corners by immersing the substrate in an isotropic etching solution for a few seconds, or by treating the substrate with thermal oxidation to make the grooves having the rounded corners, wherein the grooves with the rounded corners form the wavy pattern.

6. The method for manufacturing a working electrode of electrochemical sensor as recited in claim 5, wherein the step S3 of disposing the conductive substance on the wavy pattern is to form a conductive layer on the wavy pattern using evaporating or sputtering of physical vapor deposition.

7. The method for manufacturing a working electrode of electrochemical sensor as recited in claim 6, further comprising a step of forming a colloidal metal solution with conductive particles and colloidal solution on the conductive layer, wherein the conductive particles are formed on the conductive layer after the colloidal solution dried.

8. A working electrode of electrochemical sensor, comprising: a substrate; a wavy pattern, formed on the substrate; and a conductive substance, disposed on the wavy pattern.

9. The working electrode of electrochemical sensor as recited in claim 8, wherein the wavy pattern includes a plurality of grooves formed on the substrate, and each of the grooves has rounded corners at the edge and bottom of the each groove.

10. The working electrode of electrochemical sensor as recited in claim 8, wherein the conductive substance includes a conductive layer, or the conductive substance includes a conductive layer and a plurality of conductive particles sequentially formed on the substrate, wherein the conductive layer is disposed on a side of the substrate with the grooves.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a flow chart of a method for manufacturing a working electrode of electrochemical sensor of the present invention.

[0017] FIG. 2 is a schematic view of the substrate having openings of the Embodiment 1.

[0018] FIG. 3 is a schematic view of the substrate having a plurality of grooves of the Embodiment 1.

[0019] FIG. 4 is a schematic view of the substrate with grooves and without a protective layer of the Embodiment 1.

[0020] FIG. 5 is a schematic view of the substrate having a wavy pattern of the Embodiment 1.

[0021] FIG. 6 is a schematic view of the substrate having a conductive layer of the Embodiment 1.

[0022] FIG. 7 is a schematic view of the substrate having the conductive layer and conductive particles of the Embodiment 3.

[0023] FIG. 8 is a schematic view of the substrate having openings of the Embodiment 2.

[0024] FIG. 9 is a schematic view of the substrate having a plurality of grooves of the Embodiment 2.

[0025] FIG. 10 is a schematic view of the substrate with grooves and without a protective layer of the Embodiment 2.

[0026] FIG. 11 is a schematic view of the substrate having a wavy pattern of the Embodiment 2.

[0027] FIG. 12 is a schematic view of the substrate having a conductive layer of the Embodiment 2.

[0028] FIG. 13 is a schematic view of the substrate having the conductive layer and conductive particles of the Embodiment 2.

DETAILED DESCRIPTION

[0029] Embodiment 1: FIG. 1 is a flow chart of a method for manufacturing a working electrode of electrochemical sensor of the present invention. As shown in FIG. 1, a method for manufacturing a working electrode of electrochemical sensor of the Embodiment 1 comprises the following steps.

[0030] In step S1, providing a substrate, a substrate 10 is provided. A protective layer 11 is formed on one side of the substrate 10, as shown in FIG. 2. The substrate 10 is a silicon wafer having oxide or nitride with 1 to 100 ohm-cm resistivity.

[0031] In step S2, forming a wavy pattern on the substrate, a wavy pattern is formed on the substrate 10, as shown in FIG. 2. A plurality of openings 110 are formed on the protective layer 11 of the substrate 10 using lithography and dry etching.

[0032] A plurality of grooves 100 are formed on the substrate 10 through the plurality of openings 110 using isotropic etching, as shown in FIG. 3. The plurality of grooves 100 are semicircular grooves. An etching solution of the isotropic etching is 0.5-1.5 servings of 44-54 wt % hydrogen fluoride HF, 2.5-3.5 servings of 6.5-75 wt % nitric acid HNO.sub.3 at a temperature between 20 and 30 C. Preferably, 1 serving of 49% hydrogen fluoride HF and 3 servings of 70% nitric acid HNO.sub.3, etching temperature 25 C.

[0033] As shown in FIG. 4 and FIG. 5, the protective layer 11 is removed. Each of the grooves 100 has acute angles 101 at the edge of the each groove 100. The substrate 10 is then immersed in the isotropic etching solution, and after being immersed for a few seconds, the acute angles 101 are formed into rounded corners 102. Alternatively, the substrate 10 is treated with thermal oxidation to form the acute angles 101 into rounded corners 102. The grooves 100 with the rounded corners 102 form the wavy pattern 103.

[0034] In step S3, disposing a conductive substance on the wavy pattern, a conductive substance is disposed on the wavy pattern 103 using evaporating or sputtering of physical vapor deposition (PVD). A conductive layer 12 is formed on the wavy pattern 103 of the substrate 10 using evaporating or sputtering of physical vapor deposition, as shown in FIG. 6. The conductive layer 12 can be a chrome-copper (Cr-Cu) layer.

[0035] Embodiment 2: Referring to FIGS. 1 and 7, a method for manufacturing a working electrode of electrochemical sensor of the Embodiment 2 is based on the Embodiment 1 of the present invention described above, so the same components use the same symbols.

[0036] In the Embodiment 2, a colloidal metal solution with conductive particles 13 and colloidal solution is disposed on the conductive layer 12 of the substrate 10, wherein the conductive particles 13 are formed on the conductive layer 12 after the colloidal solution dried.

[0037] The conductive particles 13 of the colloidal metal solution can generally be prepared by reducing Gold(III) chloride trihydrate solution with sodium citrate. The conductive particles 13 can be nanometer particles of metal having a size of from 1 to 100 nm. Where the nanometer particles of metal are nanometer particles of gold, the equation is:

HAuCl.sub.4 +Na.sub.3C.sub.6H.sub.5O.sub.7.fwdarw.nano Au

[0038] As shown in FIG. 1, a method for manufacturing a working electrode of electrochemical sensor of the Embodiment 2 comprises the following steps.

[0039] In step S1, providing a substrate, a substrate 20 is provided. A protective layer 21 is formed on one side of the substrate 20, as shown in FIG. 8. The substrate 20 is a silicon wafer having oxide or nitride with 1 to 100 ohm-cm resistivity.

[0040] In step S2, forming a wavy pattern on the substrate, a wavy pattern is formed on the substrate 20, as shown in FIG. 8. A plurality of openings 210 are formed on the protective layer 21 of the substrate 20 using lithography and dry etching.

[0041] A plurality of grooves 200 are formed on the substrate 20 through the plurality of openings 210 using anisotropic etching, as shown in FIG. 9. The plurality of grooves 200 are inverted triangular grooves. An anisotropic etching solution of the anisotropic etching is 10 to 45 wt % Potassium hydroxide KOH at a temperature between 40 and 90 C. Another anisotropic etching solution can be 5 to 25 wt % tetramethylammonium hydroxide TMAH or TMAOH at a temperature between 40 and 90 C.

[0042] As shown in FIG. 10, the protective layer 21 is removed. Each of the grooves 200 has acute angles 201 at the edge and bottom of the each groove 200.

[0043] The protective layer 21 is removed after the grooves 200 are formed, as shown in FIG. 10. The substrate 20 is then immersed in the etching solution, and after being immersed for a few seconds, the acute angles 201 are formed into rounded corners 202, as shown in FIG. 11. Alternatively, the substrate 20 is treated with thermal oxidation to form the acute angles 201 into rounded corners 202, and to form the grooves 200 with inverted triangular shaped into grooves 203 with semicircular shaped. The grooves 203 with the rounded corners 202 form the wavy pattern 204.

[0044] In step S3, disposing a conductive substance on the wavy pattern, a conductive substance is disposed on the wavy pattern 204 using evaporating or sputtering of physical vapor deposition (PVD). A conductive layer 22 is formed on the wavy pattern 204 of the substrate 20 using evaporating or sputtering of physical vapor deposition, as shown in FIG. 12. The conductive layer 12 can be a chrome-copper (Cr-Cu) layer.

[0045] As shown in FIG. 13, a colloidal metal solution with conductive particles 23 and colloidal solution is disposed on the conductive layer 22 of the substrate 20, wherein the conductive particles 23 are formed on the conductive layer 12 after the colloidal solution dried.

[0046] FIG. 6 is a schematic view of the substrate having a conductive layer. The working electrode of electrochemical sensor includes a substrate 10, a wavy pattern 103, and a conductive substance, as shown in FIG. 6.

[0047] The wavy pattern 103 is formed on the substrate 10. The substrate 10 has the plurality of grooves 100, and each of the grooves 200 has rounded corners 102 at the edge of the each groove 200. The grooves 100 with the rounded corners 102 form the wavy pattern 103.

[0048] The conductive substance is disposed on the wavy pattern 103 of the substrate 10. The conductive substance is a conductive layer 12. The conductive layer 12 is formed on the wavy pattern 103 of the substrate 10.

[0049] Embodiment 3: A working electrode of electrochemical sensor of the Embodiment 3 is based on the Embodiment 1 of the present invention described above, so the same components use the same symbols. The working electrode of electrochemical sensor includes a substrate 10, a wavy pattern 103, and a conductive substance, as shown in FIG. 7.

[0050] In the Embodiment 3, the conductive substance includes a conductive layer 12 and a plurality of conductive particles 13. The conductive layer is disposed on a side of the substrate with the grooves. The conductive layer 12 and the conductive particles 13 are sequentially formed on the substrate 10.

[0051] In summary, the working electrode of the present invention has high precision and uses metal. The working electrode having nanometer particles of metal is fabricated into a chip. The surface of the detection region of the chip has a wavy pattern. The wavy pattern can increase the detection region to improve the accuracy of the detection.