TWI811747B - Biosensor apparatus - Google Patents

Abstract

A biosensor apparatus includes a substrate plate, a plurality of metal conductive layers, a plurality of working electrodes, a counter electrode and an insulating layer. Each metal conductive layer is disposed on the substrate plate and has a first upper surface. The working electrodes and the counter electrode are disposed on the first upper surface of the corresponding metal conductive layers, wherein a first top surface of each working electrode is higher than the first upper surface of the metal conductive layer, and a second top surface of the counter electrode is higher than the first top surface of each working electrode. The insulating layer covers the metal conductive layers and surrounds the working electrodes and the counter electrode, wherein a second upper surface of the insulating layer is located between the first top surface of the working electrodes and the first upper surface of the metal conductive layer such that the working electrodes and the counter electrode protrude beyond the second upper surface of the insulating layer. The above-mentioned biosensor apparatus can increase the sensing sensitivity.

Description

Biosensing device

The present invention relates to a sensing device, in particular to a biosensing device for detecting biomolecules.

In recent years, various detection methods for biomolecules have been developed to diagnose various diseases, conduct research related to physiological metabolism, or monitor environmental factors, etc. The development of Micro-electromechanical Systems (MEMS) has attracted much attention. It combines semiconductor process technology and precision mechanical technology to produce a semiconductor element for sensing optical, chemical, biological molecules or other properties on a tiny chip. However, as the semiconductor industry progresses to nanotechnology process nodes in pursuit of higher device density, higher performance and lower cost, manufacturing and design challenges drive the development of 3D design. Accordingly, developing a biosensing chip with higher performance and lower cost is an urgent problem that needs to be solved.

The present invention provides a biosensing device, which includes a plurality of protruding working electrodes and a pair of electrodes, wherein the second top surface of the counter electrode is higher than the first top surface of the working electrode to enhance the maximum electric field value of the working electrode. Thereby improving the sensitivity of sensing.

A biosensing device according to an embodiment of the present invention includes a substrate, a plurality of metal conductive layers, a plurality of working electrodes, a pair of electrodes and an insulating layer. A plurality of metal conductive layers are disposed on the substrate, and each metal conductive layer has a first upper surface. A plurality of working electrodes are disposed on the first upper surface of the corresponding metal conductive layer, wherein each working electrode includes a first top surface, and each first top surface is higher than the first upper surface of the metal conductive layer. The counter electrode is disposed on the first upper surface of the corresponding metal conductive layer and adjacent to the plurality of working electrodes, wherein the counter electrode includes a second top surface, and the second top surface is higher than the first top surface. The insulating layer covers the metal conductive layer and surrounds the plurality of working electrodes and the counter electrode, wherein a second upper surface of the insulating layer is between the plurality of first top surfaces of the plurality of working electrodes and the first upper surface of the metal conductive layer, The plurality of working electrodes and the counter electrode protrude from the second upper surface of the insulating layer.

The purpose, technical content, characteristics and achieved effects of the present invention will be more easily understood through detailed descriptions of specific embodiments and accompanying drawings below.

The disclosure will next provide many different implementations or examples to implement different features of the disclosure. The composition and configuration of each specific embodiment will be described below to simplify the present disclosure. These are examples only and are not intended to limit the disclosure. For example, a first element formed "above" or "on" a second element may include direct contact between the first element and the second element in the embodiment, or may include further contact between the first element and the second element. Other additional components prevent direct contact between the first component and the second component. In addition, reference symbols and/or letters will be used repeatedly in various examples of this disclosure. This repetition is for the purposes of simplicity and clarity and does not in itself determine the relationship between the various embodiments and/or structural configurations.

In addition, terms such as "below," "below," "lower," "above," "higher," and other similar relative spatial terms may be used herein to describe an element or feature in the drawings. A relationship to another element or feature. These relative spatial terms are intended to encompass various orientations of the device in use or operation in addition to the orientations depicted in the drawings. The above device can be oriented in other ways (rotated 90 degrees or in other directions), and the spatial relative relationship at this time can also be interpreted in the above manner.

Figure 1 illustrates a cross-sectional view of a biosensing element according to some embodiments of the present invention. As shown in FIG. 1 , the biosensing element 100 includes a substrate 103 , a metal conductive layer 106 , a second insulating layer 108 , a plurality of working electrodes 110 and a biological probe 112 . In some embodiments, the substrate 103 includes a base material 102 and a first insulating layer 104 . The substrate 103 may also include, but is not limited to, other semiconductor materials, such as gallium nitride (GaN), silicon carbide (SiC), silicon germanium (SiGe), germanium, or combinations thereof. The substrate 102 may be, for example, a silicon substrate. Depending on the design requirements in the technical field, the substrate 102 may include a variety of different doping configurations. In one embodiment, the substrate 102 may be a heavily doped, low resistivity semiconductor substrate. In another embodiment, the substrate 103 is a glass substrate without the first insulating layer 104 .

The first insulating layer 104 is disposed on the base material 102 . In one embodiment, the first insulating layer 104 may include, but is not limited to, an oxide, a nitride, an oxynitride, or a combination thereof, such as silicon oxide, silicon nitride, silicon oxynitride. The first insulating layer 104 is made of a low dielectric constant (low-K) material so that the biosensing element 100 has good insulating properties. In some embodiments, the first insulating layer 104 has a thickness of about 0.02 microns (μm) to about 0.25 microns, such as about 0.10 microns, about 0.15 microns, or about 0.20 microns.

The metal conductive layer 106 is disposed on the substrate 103 and has sidewalls 107 and a first upper surface 105 , wherein the sidewalls 107 are adjacent to the first upper surface 105 , and the second insulating layer 108 covers the sidewalls 107 . In one embodiment, the metal conductive layer 106 may include, but is not limited to, titanium (Ti), nickel (Ni), silver (Ag), aluminum (Al), copper-aluminum alloy (AlCu), copper-aluminum-silicon alloy (AlSiCu) or its combination. In one embodiment, the thickness of the metal conductive layer 106 is about 0.02 microns to about 0.7 microns, such as about 0.1 microns, 0.2 microns, 0.3 microns, 0.4 microns, about 0.5 microns or about 0.6 microns.

Each working electrode 110 is disposed on the first upper surface 105 of the metal conductive layer 106, and each has a first top surface 109 and sidewalls 111. Each first top surface 109 is higher than the first upper surface 105 of the metal conductive layer 106 , each side wall 111 is adjacent to each first top surface 109 , and the second insulating layer 108 only covers a part of each side wall 111 . Each working electrode 110 has a first height H1 protruding above the metal conductive layer 106 . In some embodiments, the first height H1 of each working electrode 110 is about 0.05 micron to about 1 micron, such as about 0.05 micron, 0.1 micron, 0.2 micron, about 0.3 micron or about 0.4 micron. In some embodiments, each working electrode 110 has a width of about 0.08 microns to about 0.4 microns, such as about 0.08 microns, 0.1 microns, 0.2 microns, or about 0.3 microns. In one embodiment, each working electrode 110 has an aspect ratio between about 0.125 and about 7.5, such as about 0.2 or about 0.3.

In some embodiments of the present invention, the shape of the working electrodes 110 may be a cylinder or a regular polygonal prism, such as a regular triangular prism, a regular tetragonal prism, a regular pentagonal prism, a regular hexagonal prism or a regular octagonal prism. In some embodiments, the working electrodes 110 may include, but are not limited to, tantalum (Ta), tantalum nitride (TaN), copper (Cu), titanium (Ti), titanium nitride (TiN), tungsten (W), Titanium (Ti), nickel (Ni), silver (Ag), aluminum (Al), copper-aluminum alloy (AlCu), copper-aluminum-silicon alloy (AlSiCu) or combinations thereof. In some embodiments, the material of the working electrodes 110 is preferably titanium nitride (TiN).

The biological probe 112 can be modified and connected to the working electrodes 110 through various conventional methods. According to various embodiments of the present invention, the biological probe 112 may include, but is not limited to, nucleic acids, cells, antibodies, enzymes, polypeptides, peptides, aptamers, carbohydrates, or combinations thereof. It should be noted that the above-mentioned biological probe 112 can identify various biological molecules. For example, when the biological probe 112 is an antibody, it can bind to a target molecule (ie, an antigen) in a sample and detect the presence of the target molecule using various conventional techniques.

The second insulating layer 108 covers the metal conductive layer 106 and surrounds the working electrodes 110 , wherein the second upper surface 113 of the second insulating layer 108 is between the first top surface 109 of the working electrodes 110 and the third surface of the metal conductive layer 106 Between an upper surface 105 , the working electrodes 110 protrude from the second upper surface 113 of the second insulating layer 108 . The above-mentioned protruding portion has a second height H2, which is the vertical distance from each first top surface 109 to the second top surface 113 of the second insulation layer 108. In some embodiments, the second height H2 is about 0.01 micron to about 0.55 micron, such as about 0.05 micron, 0.15 micron, about 0.3 micron, about 0.45 micron, about 0.5 micron or about 0.6 micron. Therefore, when a voltage is applied to the working electrodes 110, the working electrodes 110 will generate an electric field surrounding the protruding working electrodes 110. The coverage range of the electric field will not be limited to the first top surface 109 of the working electrodes 110, but will extend to the side walls 111 of the working electrodes 110, thereby greatly increasing the electrochemical reaction and thereby increasing the intensity of the signal. Under the same applied voltage, the working electrode 110 with the three-dimensional structure provides better sensitivity than the conventional planar working electrode.

In some embodiments, the second insulating layer 108 may include, but is not limited to, an oxide, a nitride, an oxynitride, a combination thereof or a compound thereof, such as silicon oxide, silicon nitride, silicon oxynitride. In some embodiments, the first insulating layer 104 is made of the same material as the second insulating layer 108 . In some embodiments, the first insulating layer 104 is made of a different material than the second insulating layer 108 .

In addition, when a voltage is applied to the working electrode 110, background noise will also be generated to interfere with the detection results. The generation of background noise is related to the cross-sectional area of the electrode. When the cross-sectional area of the electrode is larger, the intensity of background noise is higher. According to some embodiments of the present invention, when a voltage is applied to the working electrode 110, the electric field coverage range generated by the working electrode 110 is larger than that of the conventional planar working electrode. The coverage range of the electric field will not be limited to the first top surfaces 109 of the working electrodes 110 , but will extend to the sidewalls 111 of the working electrodes 110 . Therefore, when the effective electric field coverage range is the same, the width of these working electrodes 110 can be smaller than the width of conventional planar working electrodes. Therefore, the width of the working electrode 110 according to the embodiment of the present invention can be smaller than the width of the conventional planar working electrode, and thus has a smaller cross-sectional area than the conventional planar working electrode, thereby reducing the generation of background noise.

As mentioned above, in some embodiments, the first height H1 of each working electrode 110 is about 0.05 microns to about 0.6 microns. When the first height H1 of each working electrode 110 is less than 0.05 micron, the second height H2 of the protruding portion of each working electrode 110 will be less than 0.01 micron. In this case, when a voltage is applied to the working electrode 110, the effective electric field range is increased to a limited extent, resulting in an insignificant effect of improving the electrochemical reaction of the biological probe 112. According to this, it can be seen that the higher the protruding part of the working electrode 110 is, the wider the coverage range of its effective electric field is, and the better the electrochemical reaction is. However, it should be noted that the aspect ratio of the working electrode 110 is about 0.125 to about 7.5. When the aspect ratio of the working electrode 110 is greater than 7.5, it is easy to cause structural defects in the working electrode and reduce the reliability of the overall device.

Figures 2 to 12 illustrate cross-sectional views of various process stages of a method of manufacturing the biosensing element 200 according to some embodiments of the present invention. As shown in Figures 2 to 3, a substrate 203 is provided. In some embodiments, the substrate 203 includes a base material 202 and a first insulating layer 204, where the first insulating layer 204 is formed on the base material 202. The first insulating layer 204 can be formed by atomic layer deposition (ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD), chemical oxidation (Chemical Oxidation), thermal oxidation (Heat Oxidation) and/or other suitable processes. method to form. In one embodiment, the first insulating layer 204 may include, but is not limited to, an oxide, a nitride, an oxynitride, or a combination thereof, such as silicon oxide, silicon nitride, silicon oxynitride. In some embodiments, the first insulating layer 204 is formed to a thickness of about 0.02 microns to about 0.25 microns, such as about 0.10 microns, about 0.15 microns, or about 0.20 microns.

Continuing to refer to FIG. 4 , in this step, a metal conductive layer 206 is formed on the first insulating layer 204 . In some embodiments, the metal conductive layer 206 may be formed using PVD, CVD, electron beam evaporation, sputtering, electroplating and/or other suitable processes. In one embodiment, the metal conductive layer 206 may include, but is not limited to, titanium (Ti), nickel (Ni), silver (Ag), aluminum (Al), copper-aluminum alloy (AlCu), copper-aluminum-silicon alloy (AlSiCu) or its combination. In one embodiment, the metal conductive layer 206 is formed with a thickness of about 0.3 microns to about 0.5 microns, such as about 0.3 microns, about 0.4 microns, or about 0.5 microns.

Referring now to FIG. 5 , in this step, a conductive layer 208 is deposited on the metal conductive layer 206 . In some embodiments, the conductive layer 208 may be formed using PVD, CVD, electron beam evaporation, sputtering, electroplating, and/or other suitable processes. In some embodiments, conductive layer 208 may include, but is not limited to, tantalum (Ta), tantalum nitride (TaN), copper (Cu), titanium (Ti), titanium nitride (TiN), tungsten (W), or combinations thereof . In some embodiments, conductive layer 208 has a thickness of about 0.05 microns to about 0.6 microns, such as about 0.1 microns, about 0.2 microns, about 0.3 microns, or about 0.4 microns.

Referring now to FIGS. 6 to 7 , a patterning process is performed on the conductive layer 208 to form a plurality of working electrodes 212 (only a single working electrode is shown as an example). As shown in FIG. 6 , a patterned photoresist layer (not shown) is formed on the conductive layer 208 using a photomask 210 and a lithography process. This photoresist layer may be, for example, a positive photoresist or a negative photoresist. Next, coming to FIG. 7 , an etching process is performed on the conductive layer 208 using a patterned photoresist layer to form a plurality of working electrodes 212 and expose the first upper surface 205 of the metal conductive layer 206 . Each working electrode 212 has a first height H1. Each working electrode 212 has a first top surface 209 and side walls 211 . Each first top surface 209 is higher than the first top surface 205 of the metal conductive layer 206 . Each side wall 211 is adjacent to each first top surface 209 .

Continuing to refer to Figures 8 to 9, a patterning process is performed on the metal conductive layer 206. As shown in FIG. 8 , a patterned photoresist layer (not shown) is formed on the working electrode 212 and the metal conductive layer 206 using a photomask 214 and a lithography process. This photoresist layer can be, for example, a positive photoresist or a negative photoresist. . Next, coming to Figure 9, the metal conductive layer 206 is etched using a patterned photoresist layer to expose part of the upper surface of the lower first insulating layer 204, so that the metal conductive layer 206 has a side wall 207 adjacent to the first upper surface 205. and a portion of the upper surface of the first insulating layer 204 exposed below.

Referring to FIG. 10 , an insulating material layer 216 is deposited on the first insulating layer 204 , the metal conductive layer 206 and the working electrodes 212 . In this step, the insulating material layer 216 may, for example, conformally cover the first insulating layer 204, the metal conductive layer 206 and the working electrodes 212. In some embodiments, the insulating material layer 216 can be multiple layers, and the materials of each layer are different from each other. In some embodiments, the insulating material layer 216 can be multiple layers, and the materials of each layer are the same as each other. In some embodiments, the insulating material layer may be formed using PVD, CVD, plasma enhanced chemical vapor deposition (Plasma enhanced CVD, PECVD) and/or other suitable processes.

In one embodiment, the insulating material layer 216 may include, but is not limited to, oxides, nitrides, oxynitrides, or combinations thereof, such as silicon oxide, silicon nitride, silicon oxynitride. In one embodiment, the insulating material layer 216 is tetraethoxysilane.

Next, referring to FIG. 11 , a planarization process is performed on the insulating material layer 216 to form a second insulating layer 218 . In this step, a planarization process is performed on the insulating material layer 216 to obtain a second insulating layer 218 with a substantially flat upper surface. In one embodiment, the planarization process may be chemical mechanical planarization (CMP) and/or other suitable processes. In some embodiments, the insulating material layer 216 is a multi-layer insulating material layer, and the materials of each layer are different from each other, so that the planarization process efficiency is better.

Finally, referring to FIG. 12, part of the second insulating layer 218 is removed through an appropriate etching process, so that the second upper surface 213 of the second insulating layer 218 is between the first upper surface 205 of the metal conductive layer 206 and the working electrodes. 212 between the first top surface 209 . Therefore, the working electrodes 212 protrude from the second upper surface 213 of the second insulating layer 218, and the protruding portions have a second height H2, which is from the first top surface 209 to the second upper surface 213 of the second insulating layer 218. the vertical distance. In some embodiments, the second height H2 is about 0.01 micron to about 0.5 micron, such as about 0.05 micron, 0.15 micron, about 0.3 micron or about 0.45 micron. In some embodiments, biological probes can be further modified on the working electrodes 212 so that the biological probes are connected to the first top surfaces 209 of the working electrodes 212 .

Biosensing elements manufactured according to various embodiments of the present invention are compatible with various biosensing devices. Figure 13 shows a top view of the biosensing device 300 according to some embodiments of the present invention, and Figure 14A shows a cross-sectional view along line segment AA in Figure 13. As shown in Figures 13 and 14A, the biosensing device 300 includes a substrate 303, a metal conductive layer 306a, a metal conductive layer 306b, a second insulating layer 308, a plurality of working electrodes 310, a counter electrode 312, Biological probe 314, signal detection unit 316 and wire 318.

Each working electrode 310 and counter electrode 312 can be electrically connected to the signal detection unit 316 through one or more wires 318 . Accordingly, as shown in FIG. 14A, when a voltage is applied to the working electrodes 310, the electrodes 310 will generate respective electric fields E, which surround the corresponding working electrodes 310. At this time, a sample to be tested is then provided to contact the aforementioned biological probe 314. If the target molecule in the sample to be tested binds to the biological probe 314, these working electrodes 310 will generate a signal, and the generated signal will be transmitted to the signal detection unit 316 through the wire 318, thereby detecting the presence of the target molecule. .

Continuing to refer to FIG. 14A, the metal conductive layer 306b is disposed on the first insulating layer 304. The counter electrode 312 is disposed on the metal conductive layer 306b. A plurality of working electrodes 310 are arranged on the first upper surface 307 of the metal conductive layer 306a. In some embodiments, the material of metal conductive layer 306b is the same as the material of metal conductive layer 306a. In some embodiments, the material of metal conductive layer 306b is different from the material of metal conductive layer 306a. As for the substrate 303, the base material 302, the metal conductive layer 306a, the second insulating layer 308, the working electrode 310, and the biological probe 314, they can be combined with the aforementioned substrate 103, the base material 102, the metal conductive layer 106, and the second insulating layer 308. The insulating layer 108, the plurality of working electrodes 110, and the biological probe 112 are the same and will not be repeated here.

Next, referring to Figure 14B, a partial enlarged schematic diagram is shown based on Figure 14A. When a voltage is applied to the working electrodes 310, the working electrodes 310 will generate respective electric fields. Illustratively, the electric field E75 represents the electric field lines connected by 75% of the maximum electric field intensity at each point in space. In other words, the electric field intensity at each point within the range covered by the electric field E75 is greater than 75% of the maximum electric field intensity. For example, the electric field E50 represents the electric field lines connected by 50% of the maximum electric field intensity at each point in space. In other words, the electric field intensity at each point within the range covered by the electric field E50 is greater than 50% of the maximum electric field intensity. According to some embodiments, when a voltage is applied to these working electrodes 310, 75% of the maximum electric field intensity (ie, the maximum electric field intensity multiplied by 0.75) will appear at 27-27-27°C downwardly displaced from the first top surface 311 to the second height H2. 40% (that is, where the electric field lines connected by the electric field E75 intersect with these working electrodes 310); in other words, 75% of the maximum electric field intensity appears at about 60-73% of the second height H2 above the second upper surface 313 place. According to some embodiments, when a voltage is applied to these working electrodes 310, 50% of the maximum electric field strength (ie, the maximum electric field strength multiplied by 0.5) will appear at 80- 80-200 degrees downward from the first top surface 311 to the second height H2. 93% (that is, where the electric field lines connected by the electric field E50 intersect with these working electrodes 310); in other words, 50% of the maximum electric field intensity appears at the second height H2 of about 7-20% above the second upper surface 313 place.

Electric field analysis simulation

This experiment uses COMSOL Multiphysics 4.4 simulation analysis software to conduct simulation analysis of electric field strength. As shown in Table 1 below, when the working electrode is circular, Example 1 is a circular working electrode with a radius of 0.05 microns, and the maximum electric field value is 2.86 x 106 (v/m); Example 2 is a circular working electrode with a radius of 0.1 microns. The circular working electrode has a maximum electric field value of 1.85 x 106 (v/m); Example 3 is a circular working electrode with a radius of 0.2 microns, and the maximum electric field value is 7.75 x 105 (v/m).

Table I working electrode Electrode radius (µm) Maximum electric field value (v/m) Example 1 0.05 2.86 x 10 ⁶ Example 2 0.1 1.85 x 10 ⁶ Example 3 0.2 7.75 x 10 ⁵

It can be seen from the above that when the radius of the working electrode decreases, the maximum electric field value will increase. Next, as shown in Table 2 below, simulate the coverage range and intensity of the electric field in the protruding part of the working electrode. When the working electrode is a traditional planar working electrode, the height is 0 microns, so there is no side wall, and no matter 100%, 75% or 50% of the maximum electric field intensity appears on the surface of the working electrode. Next, as shown in Table 2 below, when the second height H2 of the working electrode is 0.15 microns, calculated from the top surface of the working electrode toward the lower insulation layer, 75% of the maximum electric field intensity appears at a distance of 0.05 microns from the top surface of the working electrode; and 50% The maximum electric field intensity occurs at a distance of 0.13 microns from the top surface of the working electrode.

Table II Working electrode height (µm) 100% maximum electric field intensity height 75% maximum electric field intensity height 50% maximum electric field intensity height 0 0 0 0 0.15 0 0.05 0.13

In summary, according to various embodiments of the present invention, the biosensing element has a working electrode protruding from the insulating layer. In electrochemical reactions, charged objects move faster when the electric field is larger. The result is a higher current density.

A common knowledge of the electrochemical reaction formula (Electrochemical Methods: Fundamentals and Applications. Allen J. Bard, Larry R. Faulkner, Wiley. ISBN: 0471043729) is as follows:

J _A (x,t) represents the current density of charged object A at position x and time t. z _A represents the valence of charged object A. D _A represents the diffusion coefficient of charged object A. C _A (x,t) represents the concentration of charged object A at position x and time t. ε(x) represents the electric field experienced by charged object A at position x. This protruding working electrode enables the electric field to cover a wider range, and the movement of charged objects is affected by the wider electric field covering range, which helps to improve the efficiency of the electrochemical reaction and thereby increases the intensity of the signal. Accordingly, the width of the working electrode produced by the embodiment of the present invention can be smaller than the area of the conventional planar electrode, thereby improving the sensitivity.

In the embodiment shown in Figure 14A, the protruding heights of the working electrode 310 and the counter electrode 312 are the same, that is, the first top surface 311 of the working electrode 310 and the top surface of the counter electrode 312 are located on the same plane, but are not limited to this. In one embodiment, please refer to Figure 15, the second insulating layer 308 covers the metal conductive layers 306a, 306b and their sidewalls 305, and partially covers the sidewalls 309 of the working electrode 310 and the counter electrode 312, so that the working electrode 310 and The counter electrode 312 protrudes from the second upper surface 313 of the second insulating layer 308 . What is different from the embodiment shown in Figure 14A is that the second top surface 3121 of the counter electrode 312 shown in Figure 15 is higher than the first top surface 311 of the working electrode 310. For example, the height difference between the first top surface 311 of the working electrode 310 and the second top surface 3121 of the counter electrode 312 is less than 0.15 microns. In some embodiments, the height difference between the first top surface 311 of the working electrode 310 and the counter electrode 312 is less than 0.15 microns. The height difference of the second top surface 3121 is less than 0.12 microns, or less than 0.1 microns, or less than 0.05 microns.

For example, the counter electrode 312 protrudes from the third height H3 of the metal conductive layer 306b, that is, the third height H3 from the second top surface 3121 of the counter electrode 312 to the first top surface of the metal conductive layer 306b is between 0.05 microns. to 1 micron. In some embodiments, the third height H3 of the counter electrode 312 may be 0.1 micron, 0.15 micron, 0.2 micron, 0.25 micron, 0.3 micron, 0.35 micron, 0.4 micron, 0.45 micron, 0.5 micron, 0.55 micron, 0.6 micron or 0.65 micron. Micron. In one embodiment, the counter electrode 312 protrudes beyond the fourth height H4 of the second insulating layer 308 , that is, the fourth height from the second top surface 3121 of the counter electrode 312 to the second top surface 313 of the second insulating layer 308 H4 is between 0.01 micron and 0.55 micron. In some embodiments, the fourth height H4 of the counter electrode 312 may be 0.1 micron, 0.15 micron, 0.2 micron, 0.25 micron, 0.3 micron, 0.35 micron, 0.4 micron, 0.45 micron or 0.5 micron.

Set the second height H2 of the working electrode to 0.05 microns, and use COMSOL Multiphysics 4.4 simulation analysis software to conduct simulation analysis of the electric field intensity. The analysis results are shown in Table 3. Compared with the fourth height H4 of the counter electrode being equal to the second height H2 of the working electrode (Comparative Example 2), when the fourth height H4 of the counter electrode is smaller than the second height H2 of the working electrode (Comparative Example 1), the maximum electric field value will be decline. When the fourth height H4 of the counter electrode is greater than the second height H2 of the working electrode (Embodiment 4 and Embodiment 5), the maximum electric field value can be enhanced. It should be noted that when the height difference between the fourth height H4 of the counter electrode and the second height H2 of the working electrode is greater than 0.15 microns (Embodiment 6), the maximum electric field value is also reduced. Therefore, the fourth height H4 of the counter electrode and The height difference of the second height H2 of the working electrode should be less than 0.15 microns.

Table 3 Counter electrode fourth height H4 (µm) Maximum electric field value (v/m) Comparative example 1 0.01 9.04 x 10 ⁵ Comparative example 2 0.05 9.33 x 10 ⁵ Example 4 0.1 10.00 x 10 ⁵ Example 5 0.15 9.94 x 10 ⁵ Example 6 0.2 8.73 x 10 ⁵

It can be understood that the distance between the working electrode and the counter electrode will also affect the maximum electric field value of the working electrode. For example, among multiple working electrodes arranged in an array, the maximum electric field value of the working electrode far away from the counter electrode is relatively small. In order to increase the maximum electric field value of the working electrode, please refer to Figure 16. In one embodiment, the substrate can be divided into multiple working electrode areas WEA, and multiple working electrodes 310a, 310b or 310c are arranged in each working electrode area WEA. The counter electrodes 312a and 312b include a plurality of finger structures 3122. The finger-like structures 3122 of the counter electrodes 312a and 312b extend between the plurality of working electrode areas WEA, forming a structure in which the counter electrodes 312a and 312b surround each working electrode area WEA in a U-shape or ring shape, so that each working electrode area WEA The distances between the plurality of working electrodes 310a, 310b or 310c and the counter electrode 312a or 312b are similar to enhance the maximum electric field value of the working electrode 310a, 310b or 310c that is far away from the counter electrode 312a or 312b, thereby enhancing the signal strength. In one embodiment, the major axis to minor axis ratio of each working electrode area WEA ranges from 0.8 to 1.2. In a preferred embodiment, the long axis to short axis ratio of each working electrode area WEA approaches 1.

Please refer to Figure 16 again. In one embodiment, the biosensing device of the present invention further includes reference electrodes 319a, 319b, and 319c, whose structures are similar to those of the counter electrodes, that is, the top surfaces of the reference electrodes 319a, 319b, and 319c are high on the top surfaces of the working electrodes 310a, 310b, and 310c, and their functions are well known to those skilled in the field of the present invention, so they will not be described again here. The working electrodes 310a and 310b are matched with the counter electrode 312a, and the working electrode 310c is matched with the counter electrode 312b. The working electrodes 310a and 310b can be respectively connected to different biological probes to detect different target molecules simultaneously. Alternatively, the working electrodes 310a and 310b can be connected to the same biological probe to enhance the sensing signal. In one embodiment, limited by the substrate area, multiple working electrode areas WEA can be arranged in an array and electrically connected to each other, and the working electrode 310c can be connected to the same biological probe to enhance the sensing signal.

To sum up, the plurality of working electrodes and a pair of electrodes of the biosensing device of the present invention respectively protrude from the insulating layer, and the protruding height of the counter electrode is greater than the protruding height of the working electrode. This can enhance the maximum electric field of the working electrode. value to increase the electrochemical reaction and thereby improve the sensitivity of sensing.

The foregoing summarizes features of several embodiments to enable those skilled in the art to better understand the aspects of the present disclosure. Those skilled in the art should appreciate that the present disclosure may readily be utilized as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not violate the spirit and scope of this disclosure, and various changes, substitutions and alterations can be made here without violating the spirit and scope of this disclosure. .

100:Biosensing components 102:Substrate 103:Substrate 104: First insulation layer 105: First upper surface 106: Metal conductive layer 107:Side wall 108: Second insulation layer 109:First top surface 110: working electrode 111:Side wall 112:Biological probe 113:Second upper surface 200:Biosensing components 202:Substrate 203:Substrate 204: First insulation layer 205: First upper surface 206: Metal conductive layer 207:Side wall 208:Conductive layer 209:First top surface 210: Photomask 211:Side wall 212: Working electrode 213:Second upper surface 214: Photomask 216: Insulating material layer 218: Second insulation layer 300:Biological sensing device 302:Substrate 303:Substrate 304: First insulation layer 305:Side wall 306a: Metal layer 306b: Metal layer 307: First upper surface 308: Second insulation layer 309:Side wall 310: working electrode 310a, 310b, 310c: working electrode 311:First top surface 312:Counter electrode 3121:Second top surface 3122:Finger-like structure 312a, 312b: counter electrode 313: Second upper surface 314:Biological probe 316: Signal detection unit 318:Wire 319a, 319b, 319c: reference electrode E: Electric field E75: Electric field E50: Electric field H1: first height H2: second height H3: The third height H4: The fourth height WEA: working electrode area

The embodiments of the present invention are read based on the following detailed description and drawings. Figure 1 illustrates a cross-sectional view of a biosensing element according to some embodiments of the present invention. Figures 2 to 12 illustrate cross-sectional views of biosensing elements at various stages of the manufacturing process according to some embodiments of the present invention. Figure 13 illustrates a top view of a biosensing device according to some embodiments of the present invention. Figure 14A illustrates a cross-sectional view of a biosensing device along line AA according to some embodiments of the present invention. Figure 14B is a partially enlarged schematic diagram of the cross-sectional view based on Figure 14A. Figure 15 is a cross-sectional view of a biosensing device according to some embodiments of the present invention. Figure 16 is a diagram illustrating the configuration of working electrodes, counter electrodes and reference electrodes of a biosensing device according to some embodiments of the present invention.

302:Substrate

303:Substrate

304: First insulation layer

305:Side wall

306a: Metal layer

306b: Metal layer

307: First upper surface

308: Second insulation layer

309:Side wall

310: working electrode

311:First top surface

312:Counter electrode

3121:Second top surface

313: Second upper surface

314:Biological probe

H1: first height

H2: second height

H3: The third height

H4: The fourth height

Claims (15)

A biosensing device includes: a substrate; a plurality of metal conductive layers arranged on the substrate, and each metal conductive layer has a first upper surface; a plurality of working electrodes arranged on the corresponding metal above the first upper surface of the conductive layer, wherein each working electrode includes a first top surface, and each first top surface is higher than the first upper surface of the metal conductive layer; a pair of electrodes, configured On the corresponding first upper surface of the metal conductive layer and adjacent to the plurality of working electrodes, the pair of electrodes includes a second top surface, and the second top surface is higher than the first top surface , wherein the height difference between the first top surface of each working electrode and the second top surface of the counter electrode is less than 0.15 microns; and an insulating layer covers the metal conductive layer and surrounds the plurality of working electrodes and the Counter electrode, wherein a second upper surface of the insulating layer is between the first top surfaces of the working electrodes and the first upper surface of the metal conductive layer, so that the working electrodes and the The counter electrode protrudes from the second upper surface of the insulating layer. The biosensing device according to claim 1, wherein the height difference between the first top surface of each working electrode and the second top surface of the counter electrode is less than 0.1 micron. The biosensing device according to claim 1, wherein the height difference between the first top surface of each working electrode and the second top surface of the counter electrode is less than 0.05 micron. The biosensing device of claim 1, wherein the aspect ratio of each working electrode is between 0.125 and 7.5. The biosensing device of claim 1, wherein a first height from the first top surface of each working electrode to the first upper surface is between 0.05 micron and 1 micron. The biosensing device of claim 1, wherein a second height from the first top surface to the second top surface of each working electrode is between 0.01 micron and 0.55 micron. The biosensing device of claim 1, wherein a third height from the second top surface of the pair of electrodes to the first upper surface is between 0.05 micron and 1 micron. The biosensing device as claimed in claim 1, wherein a fourth height from the second top surface of the pair of electrodes to the second upper surface is between 0.01 micron and 0.55 micron. The biosensing device according to claim 1, wherein the substrate includes a plurality of working electrode areas, a plurality of the working electrodes are arranged in each working electrode area, and the pair of electrodes includes a plurality of finger-like structures extending to between the multiple working electrode areas. The biosensing device according to claim 9, wherein the major axis to minor axis ratio of each working electrode region is between 0.8 and 1.2. The biosensing device according to claim 9, wherein the pair of electrodes surround each of the working electrode areas in a U-shape or a ring-shape. The biosensing device of claim 1, wherein the insulating layer covers a side wall of the metal conductive layer. The biosensing device of claim 1, wherein the insulating layer partially covers each of the working electrode and a side wall of the counter electrode. The biosensing device according to claim 1, wherein each working electrode is a cylinder or a regular polygonal cylinder. The biosensing device of claim 1, wherein each working electrode includes at least one biological probe, and the biological probe is nucleic acid, cell, antibody, enzyme, polypeptide, peptide, aptamer, sugar class or combination thereof.

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