KR100455283B1 - Molecular detection chip including MOSFET fabricated in the sidewall of molecular flux channel, molecular detection apparatus having the same, fabrication method for the same, and method for molecular detection using the molecular detection apparatus - Google Patents

Abstract

The chip for detecting a material according to the present invention is composed of a MOSFET formed on the sidewall of the material flow path. Since the MOSFET is formed on the sidewall of the material flow path, the integration of the material detection chip is easy. In the case of the material detecting chip according to the present invention, since the probe is directly adsorbed on the surface of the gate electrode, binding of the probe can be confirmed in-situ, and whether the target molecule is bound to the probe can be detected in-situ.

Description

Material detection chip comprising MoS FET formed on the side wall of the material flow path, a material detection device comprising the same, a manufacturing method thereof and a material detection method using the material detection device apparatus having the same, fabrication method for the same, and method for molecular detection using the molecular detection apparatus}

The present invention relates to a chip for detecting a substance, a substance detecting apparatus including the same, a method for manufacturing the same, and a substance detecting method using the substance detecting apparatus.

As the DNA sequence of human beings is known through the completion of the genome project, researches on the function of each gene and the proteins encoded by them are becoming more active, and the need for biosensors that can easily detect biomaterials is increasing.

Biosensors capable of detecting biomaterials using electrical signals are disclosed in US Pat. Nos. 4,238,757, 4,777,019, 5,431,883, and 5,827,482 and the like. U.S. Patent 4,238,757 discloses a FET consisting of a general source and drain designed to have antigens that react to specific antibodies. The FET is used to monitor the change in drain current over time to determine the concentration of antigen in solution.

US Pat. No. 4,777,019 discloses a FET in which a source is doped in the source and drain regions, a gate is formed over the source and drain regions, and a nucleotide complementary to the nucleotide to be measured is bonded onto the gate. .

U. S. Patent No. 5,431, 883 discloses a FET having a structure in which a thin film of phthalocyanin, an organic insulating material having a property of reacting with a chemical specimen and converting into a conductivity, is connected to a gate and a drain.

US Pat. No. 5,827,482 discloses a biosensor in which two FETs with molecular receptors coupled to their gates are connected in parallel to increase the sensitivity of different bonds.

However, all known biosensors are composed of conventional FETs, that is, planar FETs having source, drain, and channel layers formed on a substrate surface, thereby limiting sensor integration. In addition, since it is difficult to selectively attach the biomaterial probe only to a specific region, a separate fabrication apparatus must be used to couple the probe to the FET. However, the attached probes have a weak adhesion, and thus, there is a disadvantage in that the binding of the target molecules cannot be measured with high sensitivity. In addition, it takes a long time to detect the target molecule because it takes a long time to bind the probe and confirm whether the binding.

Therefore, there is an increasing need for a new biosensor that can easily integrate a sensor, attach a probe firmly, easily check whether it is attached in-situ, and measure the binding of a target molecule with high sensitivity. Doing.

The technical problem to be achieved by the present invention is to provide a chip for detecting a substance, which can be easily integrated and which can confirm the binding of a probe and the binding of a target molecule in a short time in-situ.

Another object of the present invention is to provide a substance detecting apparatus including the substance detecting chip.

Another technical problem to be achieved by the present invention is to provide a method for manufacturing a chip for detecting a substance.

Another object of the present invention is to provide a method for detecting a substance using a substance detection apparatus.

1 is a perspective view of a substance detection apparatus according to an embodiment of the present invention.

2 is a top view of a material detecting chip according to an embodiment of the present invention.

3 is a partial perspective view of the chip illustrated in FIG. 2.

4 is a graph illustrating I-V characteristics of the chip illustrated in FIG. 2.

5 to 9 are perspective views illustrating step-by-step manufacturing process of the chip for detecting a material according to an embodiment of the present invention.

10 is a schematic diagram showing how a material probe is coupled to a gate electrode of a material detecting chip.

11 is an I-V graph measured while detecting 15 bp DNA using the substance detection device according to the present invention.

According to an aspect of the present invention, a chip for detecting a substance includes a semiconductor substrate, a microchannel formed on a surface of the substrate, and a MOSFET formed on sidewalls of the microchannel.

Preferably, the gate electrode of the MOSFET is formed of a thin film of gold, and a thiol group-attached material probe is attached to the surface of the gate electrode by a self assembled monolayer method.

In another aspect, an apparatus for detecting a substance according to the present invention includes a substrate, a material sample loading part formed on the surface of the substrate, at least one flow path having one end connected to the sample loading part to become a passage of the material sample, and And a material detecting device kit including a material detecting chip mounting unit located at an end of the flow path and the material detecting chip installed in the material detecting chip mounting unit.

According to the method of manufacturing a material detecting chip for achieving the above another technical problem, first, an oxide film is formed on the surface of a semiconductor substrate. Subsequently, the surface of the substrate is etched to form a microchannel having at least one square corner, and then, the dopant is doped into the sidewall of the microchannel, and the substrate is treated with an etchant to remove a portion of the impurity region formed on the sidewall of the microchannel. Define the channel region of the MOSFET. Subsequently, after an oxide film is formed on the channel region, a gate electrode made of gold is formed on the channel region to complete a material detecting chip.

Preferably, the step of defining the channel region uses a mechanism in which the impurity region is selectively removed along the rectangular corner.

In the defining of the channel region, it is preferable to select an etching end point by applying a reverse bias to the substrate to sense a change in current.

According to a material detection method according to the present invention for achieving the above another technical problem, first, a material probe sample is provided to a material sample loading section formed on the surface of the kit substrate for a material detection device, and one end of the material probe sample is It moves along the flow path of the kit connected to the loading part and passes through the fine flow path of the material detecting chip connected to the other end of the flow path to be coupled to the gate electrode upper surface of the MOSFET formed on the sidewall of the flow path. Next, the voltage and current characteristics across the gate electrode are measured. Subsequently, a target sample is provided to the loading unit, and the target sample moves along the flow path of the kit to allow the target sample to react with the probe while passing through the fine flow path of the material detecting chip connected to the other end of the flow path. Finally, the target material is detected by measuring the voltage and current characteristics applied to the gate electrode to detect a difference between the voltage and current characteristics measured after the probe coupling.

Preferably, after the probe is coupled to the gate electrode, further comprising the step of providing a cleaning solution to the sample loading unit to remove the material probe not bound to the gate electrode, and after the target material is bound to the probe, the sample loading The part is provided with a cleaning liquid to remove the target sample that did not react with the probe.

In the present invention, the substance probe or target substance is used nucleic acid, protein, enzyme substrate, cofactor or oligosaccharide. Preferably the nucleic acid is single-stranded DNA, single-stranded RNA or single-stranded PNA and the protein is an agonist for cell membrane receptors, an antagonist for cell membrane receptors, toxins, viral epitopes, hormones, peptides, enzymes or monoclonals It is an antibody. More preferably, the substance probe is a single stranded nucleic acid and the target substance is a single stranded nucleic acid that hybridizes with the probe.

The chip for detecting a substance according to the present invention has the advantage of being easy to be highly integrated and confirming in-situ binding of a probe and a target molecule.

Hereinafter, a chip for detecting a substance according to the present invention, an apparatus for detecting a substance including the same, a manufacturing method of the substance detecting chip, and a method for detecting a substance using the apparatus for detecting a substance will be described. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. In the drawings, the thicknesses of the films are exaggerated for convenience of description, and the same reference numerals in the drawings denote the same members.

1 is a perspective view of an apparatus for detecting a substance according to an embodiment of the present invention.

The apparatus for detecting a substance consists of a substance detecting kit 10 and a substance detecting chip (not shown) installed in the kit 10. The material detecting kit 10 includes at least one material sample loading part 20 on a surface of the substrate 15, and the material sample loading part 20 is a chip installation part for detecting a material through the flow path 30. Connected to 40). The width and depth of the flow path 30 is such that the material sample can flow by capillary action.

Unexplained reference numeral 50 denotes a sample providing device and 55 denotes a sample, respectively.

Although not shown in the drawing, the kit 10 includes various electrical equipments capable of transmitting and receiving electrical signals to the material detecting chip (not shown) installed in the material detecting chip mounting unit 40.

In the present exemplary embodiment, the case in which the material detecting chip is separately separated and installed or separated in the kit 10 only when necessary is described. However, if necessary, the material detecting chip may be integrally formed with the kit.

2 is a partial top view of a chip for detecting a material according to an embodiment of the present invention installed in an installation unit (40 in FIG. 1) of the kit for detecting a substance.

A fine flow path 30 'is formed that is connected to the other end of the flow path 30 to which the material sample loading portion 20 and one end of the kit 10 shown in FIG. 1 are formed, and is opposite to the fine flow path 30'. The material sample outlet 60 is formed in the. The source electrode 150S, the drain electrode 150D, and the gate electrode 150G are formed on the surface, and the wirings 150 connected to the source / drain electrodes 150S and 150D are formed.

A structure of the material detecting chip according to an embodiment of the present invention will be described in detail with reference to FIG. 3, which is a partial perspective view of the material detecting chip shown in FIG. 2.

A fine flow path 105 of a material sample is formed on the surface of the semiconductor substrate 100, and a MOSFET is formed on the sidewall of the fine flow path 105. The MOSFET is defined in the corner sidewall portion of the microchannel 105 by the source region 120S and the drain region 120D and the source / drain regions 120S and 120D formed by doping impurities into the sidewall of the microchannel 105. Channel region 130. The gate electrode 150G is formed on the channel region 130 via the gate insulating layer 132. The gate electrode 150G is preferably formed of a thin film of gold so that the probe for detecting a substance can be bonded by a self-assembled tomography method. In addition, wirings 140 are formed on the surface of the substrate 100 to connect the source region 120S and the drain region 120D to the source electrode 150S and the drain electrode 150D.

The I-V characteristic curve of the material detecting chip shown in FIG. 3 is shown in FIG. 4. It can be seen from the graph of FIG. 4 that the chip for detecting a material according to an embodiment of the present invention has electrical characteristics of a normal MOSFET.

Hereinafter, a manufacturing process of the material detecting chip illustrated in FIG. 3 will be described with reference to FIGS. 5 to 9.

First, as shown in FIG. 5, the silicon oxide film 102 is formed on the semiconductor substrate 100 to have a thickness of 1.5 to 2.0 μm. As the semiconductor substrate 100, it is preferable to use an n-type silicon substrate having a crystal direction of (100).

Subsequently, as illustrated in FIG. 6, a micro-channel 105 having at least one rectangular corner is formed on the surface of the substrate 100 using a photolithography process. The reason for having at least one rectangular corner is explained in the subsequent process. In this embodiment, the flow path 105 in the a-a 'direction is formed long and the flow path 105 in the b-b' direction is formed to have a length sufficient to form at least one square corner, but the flow path in both directions In the case where all are required, the flow path 105 in the bb 'direction may also be formed to be long to form an intersection.

Subsequently, as illustrated in FIG. 7A, impurity ions are doped over the entire surface of the substrate 100. Impurity ions use P-type impurities. For example, when boron is used, doping is performed at a concentration of about 10 ¹⁶ / cm 2 to 10 ¹⁸ / cm 2. After adjusting the implantation conditions (temperature and time), impurity ions may be doped only on the sidewalls of the flow path 105 and not doped on the bottom surface of the flow path 105 using a removal time according to the oxide film thickness. Subsequently, through the diffusion process, as shown in FIG. 7B, which is a partially enlarged cross-sectional view of FIG.

The wet etching solution is treated to the resultant of FIG. 7A (b) to perform an etching process. It is preferable to use TMAH solution as the wet etching solution. At this time, etching is selectively performed only at the corner portion of the flow path 105, so that a region 130 having a part of the impurity region opened as shown in FIG. 8A is formed on the sidewall. As a result, the source region 120S, the drain region 120D, and the channel region 130 are completed on the sidewall of the flow path 105.

The selective etching occurs only at the corner portions because the crystal directions of the regions exposed to the etchant are different as shown in FIG. 8B. That is, the bottom surface of the flow path 105 is the (100) plane which is the crystal direction of the original silicon substrate, while the crystal direction of the sidewall of the flow path 105 formed by etching becomes the (111) plane. Therefore, the etching proceeds selectively at a predetermined angle at the rectangular corner where the (111) planes gather.

Whether the impurity region 110 is opened to form the channel region 130 can be easily determined by performing etching while applying reverse bias to the substrate. When the impurity region 110 is shorted, when a reverse bias is applied, current does not flow, but etching proceeds, and when the impurity region 110 is opened in the corner region, current begins to flow at that moment. Therefore, the etching end point can be easily selected based on the amount of change in the current.

Finally, as shown in FIG. 9, the gate insulating layer 132 is formed on the entire surface of the substrate on which the source region 120S, the drain region 120D, and the channel region 130 are formed, and the gate electrode 150G is formed. do. The gate insulating film 132 is formed of a silicon oxide film having a thickness of 300 to 800 Å, and the gate electrode 150G is formed of a gold thin film so that the probe can be easily and densely bonded. It is preferable to complete the gate electrode 150G by first forming a chromium thin film and forming a gold thin film before the gold thin film is formed so that the gate electrode 150G composed of the gold thin film adheres well to the gate insulating film 132. . Subsequently, the wire 140 and the source / drain electrodes 150S and 150D connected to the source / drain regions 120S and 120D are formed through a conventional process to complete the material detecting chip.

A method of detecting a substance using the apparatus for detecting a substance according to the present invention will be described with reference to FIGS. 1 and 3. First, the surface of the material detecting chip is cleaned with a piranha solution (H ₂ SO ₄ : H ₂ O = 3: 1), and then washed with deionized water, dried with nitrogen gas, and then used with UV ozone. To remove organic material from the chip surface. Similarly, the surface of the kit is cleaned in the same manner. When the cleaning is completed, the material detecting chip shown in FIG. 3 is installed in the material detecting chip mounting unit 40 of the kit 10 shown in FIG. 1. Subsequently, a material probe sample (55 in FIG. 1) is provided to the material sample loading unit (20 in FIG. 1). As the material probe sample, a material probe sample having a thiol group bonded to the terminal is used. The material probe sample is moved by capillary action along the flow path (30 in FIG. 1) connected to the loading unit (20 in FIG. 1) and passes through the micro flow path (105 in FIG. 3) of the material detection chip connected to the flow path. The gate electrode 150G of the MOSFET formed on the sidewalls of the microchannels is bonded by a self assembled monolyaer. A state where the probe is coupled to the surface of the gate electrode 150G is shown in FIG. 10. In the self-assembled tomography method, a probe is bonded to an upper surface of a gold gate electrode 150G by using a thiol group as a linker on a gold thin film. In FIG. 10, 210 denotes a thiol group and 220 denotes a probe. As described above, when the probe is selectively attached to the gold gate electrode 150G using the thiol group 210 as a linker by the self-assembled tomography method, as shown in FIG. 10, the probe is very dense and well aligned. It is possible to bind and the binding force is strong, it is possible to maintain a very stable state in the reaction with the target molecule in the subsequent process.

As the probe, a nucleic acid, protein, enzyme substrate, cofactor or oligosaccharide corresponding to the target substance to be detected may be used. Nucleic acids include single-stranded DNA, single-stranded RNA, or single-stranded PNA. Proteins include agonists for cell membrane receptors, antagonists for cell membrane receptors, toxins, viral epitopes, hormones, peptides, enzymes, or monoclonal antibodies. For example.

When the coupling of the probe is completed, the voltage and current characteristics applied to the gate electrode are measured.

Subsequently, a target sample to be detected is provided to the loading unit (20 in FIG. 1). The target sample refers to all samples separated from a living body or synthesized samples. The target sample moves along the flow path (30 in FIG. 1) connected to the loading unit (20 in FIG. 1) and passes through the fine flow path (105 in FIG. 3) of the material detecting chip connected to the flow path (FIG. 10). To 220).

Finally, the voltage and current characteristics applied to the gate electrode 150G are measured to detect a difference between the voltage and current characteristics measured after the probe coupling to detect whether the target material is coupled.

When the detection is completed and the other target material is to be detected, the probe is separated from the gold gate electrode 150G. The probe may be washed with the pyranha solution (H ₂ SO ₄ : H ₂ O = 3: 1) to separate the probe from the gate electrode 150G.

Subsequently, the target sample is detected through the same process as the previous step by using a probe corresponding to the target sample to be newly detected.

That is, according to the present invention, the self-assembled tomography method in which the probe is coupled to the upper surface of the gold gate electrode 150G is very easy to attach, detach, and reattach the probe. That is, since the detection apparatus according to the present invention has excellent reproducibility, there is an advantage that various probes can be easily used.

The present invention is described in more detail with reference to the following experimental examples, which are not intended to limit the present invention.

DNA detection

After installing the chip shown in FIG. 3 in the chip mounting unit 40 of the kit 10 shown in FIG. 1, the current flowing by applying a voltage to the chip was measured. Subsequently, the phosphate buffer buffer was first injected into the sample loading unit 20 of the kit 10. As the buffer was injected, the current flowing through the chip was continuously measured. As a result, the current increased after the injection of the buffer as in the region A of FIG. After observing the flow of the current for about 30 minutes, after the current was stabilized, a 15bp synthetic DNA (5'-thiol-GTTCTTCTCATCATC-3 ') probe having a thiol group substituted at the 5' end was provided to the sample loading unit 20. . After providing the DNA probe, the current decreased as shown in region B of FIG. 11. This indicates that the probe DNA was bonded to the surface of the gate electrode (150G of FIG. 3) made of a gold thin film by self-assembly tomography. That is, the binding of the probe DNA could be confirmed in-situ. Subsequently, deionized water was provided to the sample loading unit 20 at a time point at which it was determined that the current was sufficiently reduced by observing the change in the current, and thus, unattached DNA probes and phosphate buffer were removed. . Subsequently, in order to provide an optimal environment for hybridization of the probe DNA and the target DNA, the flow of current was observed for about 1 hour after the Tris-EDTA buffer was provided to the sample loading unit 20. Subsequently, the target DNA complementary to the probe DNA at the time point corresponding to point C of FIG. 11 was provided to the sample loading unit 20, and then the current was measured. After providing the target DNA, the current flowing through the chip was reduced as shown in FIG. This confirmed in-situ that the target DNA and the probe DNA hybridized.

The chip for detecting a material according to the present invention is composed of a MOSFET formed on the sidewall of the material flow path. Since the MOSFET is formed on the sidewall of the material flow path, the integration of the material detection chip is easy. In the case of using the material detecting chip according to the present invention and using the self-assembled tomography method, since the probe is directly adsorbed on the surface of the gate electrode, binding of the probe can be confirmed in-situ, and whether the target molecule is bound to the probe. Can be detected. In addition, since the MOSFET is highly integrated, there is an advantage that the detection sensitivity can be increased. On the other hand, since the self-assembled tomography method is used, the probes are tight and dense, so that stable detection results can be obtained. Various target materials can be detected using various probes by the reproducibility of the self-assembled tomography method.

Claims (19)

Semiconductor substrates; A microchannel formed on the substrate surface and serving as a passage for the material sample; And And a MOSFET formed on sidewalls of the micro-channels. The chip of claim 1, wherein the gate electrode of the MOSFET is formed of a gold thin film. 3. The chip of claim 2, wherein a material probe having a thiol group is attached to the surface of the gate electrode by a self-assembled tomography method. The chip of claim 1, wherein the substance sample is a nucleic acid, a protein, an enzyme substrate, a cofactor, or an oligosaccharide. The chip of claim 4, wherein the nucleic acid is single-stranded DNA, single-stranded RNA or single-stranded PNA. The chip of claim 4, wherein the protein is an agonist for a cell membrane receptor, an antagonist for a cell membrane receptor, a toxin, a viral epitope, a hormone, a peptide, an enzyme, or a monoclonal antibody. Board; A material sample loading unit formed on the substrate surface; At least one flow path, one end of which is connected to the sample loading part and becomes a passage of the material sample; And And a material detecting device kit including a chip detecting part installed at the end of the flow path. A material detection device provided in the material detection chip mounting unit of the kit and including a micro flow path of a material sample formed on a surface of a semiconductor substrate to correspond to the charge and a MOSFET formed on a sidewall of the micro flow path Device. 8. The apparatus of claim 7, wherein the gate electrode of the MOSFET is formed of a thin film of gold. The substance detection apparatus according to claim 8, wherein a biomaterial probe having a thiol group is attached to the surface of the gate electrode by a self-assembled tomography method. Forming an oxide film on the surface of the semiconductor substrate; Etching the surface of the substrate to form a microchannel having at least one rectangular corner; Doping impurities into the sidewalls of the microchannels; Treating the substrate with an etchant to remove a portion of the impurity region formed on the sidewalls of the microchannel to define a channel region of the MOSFET; Forming an oxide film on the channel region; And And forming a gate electrode made of gold on the channel region. The method of claim 10, wherein the defining of the channel region comprises using a mechanism in which the impurity region is selectively removed along the rectangular corner. The method of claim 10, wherein the defining of the channel region comprises applying an inverse bias to the substrate to detect a change in current to select an etch termination point. (a) providing a substance probe sample to a substance sample loading portion formed on a surface of a kit substrate for a substance detection device; (b) a MOSFET formed on the sidewalls of the microchannel while the material probe sample moves along the channel of the kit connected to the loading unit and passes through the microchannel of the material detecting chip connected to the other end of the channel; Coupling to an upper surface of the gate electrode; (c) measuring voltage and current characteristics across the gate electrode; (d) providing a target sample to the loading unit; (e) reacting the target sample with the probe while moving along the flow path of the kit and passing through the fine flow path of the material detecting chip connected to the other end of the flow path; And (f) detecting a target material by measuring a voltage and current characteristic applied to the gate electrode and detecting a difference between the voltage and current characteristic measured in the step (c). The method of claim 13, wherein the gate electrode of the MOSFET is formed of a thin film of gold, The substance probe is a substance detection method, characterized in that the thiol group is attached to the end. 15. The method of claim 13 or 14, wherein the probe is a nucleic acid, a protein, an enzyme substrate, a cofactor or an oligosaccharide. The method of claim 15, wherein the nucleic acid is single stranded DNA, single stranded RNA, or single stranded PNA. The method of claim 15, wherein the protein is an agonist for cell membrane receptor, an antagonist for cell membrane receptor, a toxin, a viral epitope, a hormone, a peptide, an enzyme, or a monoclonal antibody. 15. The method of claim 13 or 14, wherein the substance probe is a single stranded nucleic acid and the target substance is a single stranded nucleic acid hybridized with the probe. The method of claim 13, further comprising the step of removing the material probe that is not bound to the gate electrode by providing a cleaning solution to the sample loading unit after the step (b), And removing the target sample that has not reacted with the probe by providing a cleaning liquid to the sample loading unit after the step (e).