KR101061554B1 - Sensor with nano gaps and method for manufacturing same - Google Patents

Abstract

Nanogap sensor according to an embodiment of the present invention is a source electrode, a drain electrode, a channel connecting the source electrode and the drain electrode, and a gate spaced adjacent to the channel so as to be more easily manufactured And an electrode, wherein the source electrode, the drain electrode, the channel, and the gate electrode are made of a silicon layer doped with the same type of material.

Method of manufacturing a nano-gap biosensor according to an embodiment of the present invention is a silicon layer forming step of applying a silicon layer on a substrate, a resist layer forming step of applying a resist layer on the silicon layer, and in the resist layer A resist layer patterning step of forming a pattern, a silicon layer patterning step of forming a nanogap by etching the silicon layer, a resist layer removing step of removing the resist layer, and an impurity doping step of doping impurities entirely into the silicon And attaching the receptor to position the receptor in the nanogap that reacts with the substance to be detected.

Nanogap, sensor, doping, electrode

Description

Sensor with nano gap and manufacturing method thereof {SENSOR HAVING NANO-GAP AND FABRICATING METHOD THEREOF}

The present invention relates to a sensor having a nano gap and a method of manufacturing the same, and more particularly, to a sensor having a nano gap and a method of manufacturing the same that can form electrodes in a single doping.

Nano Technology (NT), along with Information Technology (IT) and Biotechnology (BT), is attracting attention as a new paradigm that will lead industrial development in the 21st century.

In addition, nanotechnology is a convergence of various scientific and technological fields such as physics, chemistry, biology, electronics, and materials engineering, overcoming the limitations of existing technologies, and innovating technology in various industries to dramatically improve the quality of human life. It is expected to improve.

Biosensors are detectors that detect specific molecules that make up organisms, such as enzymes and antibodies. There is a method of detecting by chemical, optical, and electrical methods, among which the electrical detection method has the advantage of a simple detection equipment, less signal loss during detection.

Detection device using nano structure has advantages such as high sensitivity, fast response, low power consumption and miniaturization. Until now, a lot of nano-detection devices applied to the sensing part of nano-materials such as nanowires and nanotubes have been studied. However, since these devices fabricate devices by manipulating nanomaterials that have already been produced by synthetic methods, there is a problem in that yield is low and it is difficult to manufacture devices reproducibly.

Recently, a sensor using a nano gap as a sensing part has been proposed. By injecting a solution containing biomaterials between the nanogaps, and fixing the biomaterials in the nanogaps, specific biomaterials can be detected by changing the electrical properties across the nanogaps. Nano gaps can be used as electrical sensors. Fabrication of nanogap by semiconductor process has the advantage that it is easy to control the width, length and characteristics of nanogap and can be produced in large quantities with reproducibility.

However, since the two-terminal method of measuring the electrical characteristics of both ends of the nanogap is used, there is a low detection sensitivity.

In order to overcome this problem, a transistor-type nanogap field effect device including a source electrode, a drain electrode, a channel, and a gate electrode has been proposed. In the case of a device in which a nanogap exists vertically between the channel layer and the gate electrode layer, a phenomenon in which the nanogap collapses due to adhesive force and surface tension occurs during the device fabrication process or during the detection experiment. There is difficulty.

To overcome this, a nanogap field effect device has been proposed in which a horizontal nanogap exists between a channel and a gate electrode. However, there is a disadvantage in that the device fabrication process becomes very complicated to dope the channel and the other electrode in opposite types.

The present invention is to solve the problems as described above, an object of the present invention is to provide a nano-gap sensor and a manufacturing method thereof that is easy to manufacture.

The nanogap sensor according to an embodiment of the present invention includes a source electrode, a drain electrode, a channel connecting the source electrode and the drain electrode, and a gate electrode spaced apart from and adjacent to the channel. The electrode, the drain electrode, the channel, and the gate electrode are made of a silicon layer doped with the same type of material.

The source electrode, the drain electrode, the channel, and the gate electrode may be doped with a P-type material, an anode of a power source is connected to the drain electrode, a cathode of the power source is connected to the source electrode, and the gate electrode The anode of the power supply can be connected to the.

The source electrode, the drain electrode, the channel, and the gate electrode may be doped with an N-type material, an anode of a power source is connected to the drain electrode, a cathode of the power source is connected to the source electrode, and the gate electrode The cathode of the power source can be connected to the.

The source electrode, the drain electrode, the channel, and the gate electrode may be doped with the same material, and the gate electrode may be one or two or more, and may be spaced apart from each other with the channel and the nano gap therebetween. have.

The nanogap between the gate electrode and the channel may be attached with a receptor that reacts with the detection target material, and a metal terminal may be attached to the drain electrode, the source electrode and the upper surface of the gate electrode. In addition, an oxide layer may be formed on the drain electrode, the source electrode, and the gate electrode, and the drain electrode, the source electrode, and the gate electrode may have the same height.

In addition, the channel may have a width of 10 nm to 300 nm, and may be formed to have a length of 100 nm to 50000 nm, and the nano gap may be formed to have a width of 10 nm to 300 nm.

Method of manufacturing a nano-gap biosensor according to an embodiment of the present invention is a silicon layer forming step of applying a silicon layer on a substrate, a resist layer forming step of applying a resist layer on the silicon layer, and in the resist layer A resist layer patterning step of forming a pattern, a silicon layer patterning step of forming a nanogap by etching the silicon layer, a resist layer removing step of removing the resist layer, and an impurity doping step of doping impurities entirely into the silicon And attaching the receptor to position the receptor in the nanogap that reacts with the substance to be detected.

The impurity may be formed of a P-type material or an N-type material. In the silicon layer patterning step, a drain electrode and a source electrode, and a channel connecting the drain electrode and the source electrode and a gate spaced apart from the channel are adjacent to each other. Electrodes can be formed.

The method of manufacturing a nanogap sensor may further include attaching a metal electrode to an upper surface of the drain electrode, the source electrode, and the gate electrode, and an oxide layer may be formed on the semiconductor layer.

The impurity doping step may be performed after the resist layer removing step, and the impurity doping step may be performed after the silicon layer forming step.

In the impurity doping step, when the nanogap is referred to as G1 (nm) and the dopant amount of the impurity is D1, 0.01 * G1 * 1E13atoms / cm ³ ≤D1≤18E19-G1 * 8E17atoms / cm ³ . .

According to the present invention, a nanogap sensor can be manufactured with only one doping. Since the nanogap between the channel and the gate electrode is a horizontal nanogap spaced horizontally, it is possible to prevent the nanogap from collapsing, the manufacturing process is simpler, and the target detection material is easily accessed.

In the present invention, "on" means to be located above or below the target member, and does not necessarily mean to be located above the gravity direction.

In addition, in the present description, "nano gap sensor" means a sensor having a nano gap, and "nano gap" means a gap having a width of a nano unit size. Meanwhile, in the present description, 'channel' means a passage through which electrons or holes move, and 'type' means a P-type type or an N-type type.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

1A to 2J are process charts illustrating a method of manufacturing a nanogap biosensor according to an embodiment of the present invention.

1A to 1J, the method of manufacturing a nanogap sensor according to the present embodiment may include forming a silicon layer 112 and applying a silicon layer 112 on a substrate 110. Forming a resist layer 114 on the resist layer 114, patterning the resist layer 114 forming a pattern on the resist layer 114, and etching the silicon layer 112 to form a nanogap 140. Patterning the silicon layer 112 to form a layer), removing the resist layer 114 to remove the resist layer 114, and impurity doping step of doping impurities to the silicon layer 112 as a whole. And attaching the receptor 115 to position the receptor 115 in the nanogap 140.

As shown in FIG. 1A, a substrate 110 is prepared. The substrate may be made of an insulating material, such as SiO ₂ , glass.

As shown in FIG. 1B, a silicon layer 112 is formed on the substrate 110. The silicon layer 112 may be formed by deposition, coating, growth, or the like.

As shown in FIG. 1C, a resist layer 114 is formed on the silicon layer 112. The resist layer 114 may be formed of a photocurable resist or a thermosetting resist, and may be formed on the silicon layer by spin coating or dispensing.

The resist layer 114 is patterned as shown in FIG. 1D. The resist layer 114 may be patterned in a variety of ways, including imprint lithography, E-beam lithography, optical lithography, and the like.

As shown in FIG. 1E, the silicon layer 112 formed under the resist layer 114 is etched to form a pattern on the silicon layer 112.

Plasma is irradiated to the substrate 110 to perform etching by dry etching. In the present embodiment, the etching is performed by dry etching, but the present invention is not limited thereto, and the etching may be performed by wet etching.

As a result of this etching, as illustrated in FIG. 2, the source electrode 182, the drain electrode 184, the gate electrodes 120 and 130, and the channel 186 are formed. The source electrode 182, the drain electrode 184, the gate electrodes 120 and 130, and the channel 186 are formed of the silicon layer 112 protruding over the substrate 110.

The channel 186 connects the source electrode 182 and the drain electrode 184. The gate electrodes 120 and 130 are spaced apart from the channel 186 to form the nanogap 140.

As shown in FIG. 1F, the resist layer 114 is removed and the silicon layer 112 is doped with impurities.

As described above, although the silicon layer 112 is patterned, the resist layer 114 is removed, and the silicon layer 112 is doped with impurities, the present invention is not limited thereto. The impurity doping step may be performed after the step of forming the silicon layer 112 on the substrate 110. According to this, after doping the impurities, a resist layer is formed on the silicon layer.

The impurity may be made of a Group 3 material such as boron (Br) gallium (Ga) or a Group 5 material such as phosphorus (P) and arsenide (As). The impurity is doped by ion implantation. The impurity ions 151 are accelerated and collided with the silicon layer 112 to insert ions into the silicon layer 112. As described above, when doping is performed by an ion implantation method, impurities can be easily implanted by a desired amount.

The entire silicon layer 112 is doped so that the source electrode 182, the drain electrode 184, the gate electrodes 120 and 130, and the channel 186 are doped with the same impurity. That is, the silicon layer 112 is formed of only one type, and the P-type impurity and the N-type impurity do not exist together.

The dose of the impurity particles incident on the silicon layer 112 when the width of the nano-gap (140), 100nm, to be in 10E19atoms / cm ³ or less, when the nanogap 200nm must be more than 2E19atoms / cm ^3. In other words, if the nanogap is G1 (nm) and the dose is D1, D1≤18E19-G1 * 8E17atoms / cm ³ . Doping with a larger dose amount has a problem that the current change of the channel 186 according to the gate voltage is too small to operate as a sensor.

In addition, the dose amount of the impurity particles incident on the silicon layer 112 should be 1E13 atoms / cm ³ or more based on when the nano gap width is 100 nm. Doping with a smaller dose amount has a problem that it is difficult to measure the change in current because little current flows in the channel.

In summary, when the nanogap is G1 (nm) and the dose is D1, D1 must satisfy the following Equation 1.

[Equation 1]

0.01 * G1 * 1E13atoms / cm ³ ≤D1≤18E19-G1 * 8E17atoms / cm ³

As illustrated in FIG. 1G, metal terminals 116 are formed on the source electrode 182, the drain electrode 184, and the gate electrodes 120 and 130. The metal terminal 116 may be connected to the power supply and the electrodes 120, 130, 182, and 184 well. The metal terminal 116 is not necessarily formed, and a wire may be directly attached to the electrode.

As shown in FIG. 1H, an oxide film 118 is formed on the silicon layer 112 to increase electrical stability of the device. By the presence of the oxide film between the nanogap, the electron tunneling effect between the gate electrode and the channel can be reduced, and the electrical stability is improved. Accordingly, the oxide film 118 is formed on the source electrode 182, the drain electrode 184, the channel 186, and the gate electrodes 120 and 130. The oxide film can be formed by thermal oxidation, vapor deposition, or the like. When the oxide film is formed by the deposition method, the oxide film 118 may be formed on the surface of the metal terminal 116 as well as the silicon layer 112. On the other hand, when the oxide film is formed by the thermal oxidation method, the oxide film 118 is not formed on the surface of the metal terminal 116, and the oxide film may be formed only on the silicon layer 112.

As shown in FIG. 1I, a receptor 115 that specifically reacts with the target material 117 to be detected is attached to the nanogap 140. In this case, the receiver 115 may be attached to the gate electrodes 120 and 130 and may be attached to the channel 186. By varying the type of receptor 115, the presence of various materials can be confirmed.

As shown in FIG. 1J, when the target material 117 is located in the nanogap 140, the amount of current passing through the channel 186 is changed. In other words, the gate voltage that controls the amount of current in the channel is changed. Through this, the presence of the target material 117 may be detected.

2 is a perspective view illustrating a nanogap sensor according to an embodiment of the present invention.

Referring to FIG. 2, the nanogap sensor according to the present exemplary embodiment includes a source electrode 182 and a drain electrode 184, and a channel 186 connecting the source electrode 182 and the drain electrode 184. do. The source electrode 182, the drain electrode 184, and the channel 186 are formed of a silicon layer protruding from the substrate 110.

The channel 186 may have a width of 10 nm to 300 nm, and the length of the channel 186 may be 100 nm to 50000 nm.

Gate electrodes 120 and 130 that are spaced apart from the channel 186 to form the nanogap 140 are positioned at both sides of the channel 186. The nano gap 140 may have a width of 10 nm to 300 nm. If the width of the nanogap 140 is smaller than 10 nm, the detection target material may not be properly positioned between the nanogap 140 or the current may change due to a small voltage change, and thus the current change may be due to the target material. There is a problem that is difficult to distinguish.

In addition, when the width of the nanogap 140 is greater than 300 nm, the distance between the gate electrodes 120 and 130 and the channel 140 is too far, so that the influence of the field generated at the gate electrodes 120 and 130 may affect the channel 186. It may not be properly delivered, and also the problem that the target detection material is difficult to detect the presence or absence of the target detection material is low because the influence of the nanogap characteristics.

The gate electrodes 120 and 130 are also made of a silicon layer protruding from the substrate 110. The gate electrodes 120 and 130 include a first gate electrode 120 disposed adjacent to one side of the channel 186 and a second gate electrode 130 disposed adjacent to the other side of the channel 186. In the present exemplary embodiment, the gate electrodes 120 and 130 are illustrated as being made of two, but the present invention is not limited thereto. The gate electrode may be made of one or more than two. The upper limit is not placed on the number of gate electrodes because the number of gate electrodes is too large. However, although the number of gate electrodes is unreasonable in terms of manufacturing cost, the larger the number of gate electrodes, the higher the measurement sensitivity.

As described above, the source electrode 182, the drain electrode 184, the channel 186, and the gate electrodes 120 and 130 are formed of a silicon layer doped with the same type of material. These structures are semiconducting in one doping and are therefore doped with the same material.

As such, when the source electrode 182, the drain electrode 184, the channel 186, and the gate electrodes 120 and 130 are formed by only one doping, the nanogap sensor may be more easily manufactured. In addition, since they are made of the same layer of material, they are made of the same height.

Accordingly, since the channel 186 and the gate electrodes 120 and 130 are formed at the same height and the nano gaps 140 are horizontally spaced horizontally spaced apart from each other, the collapse of the nano gaps can be prevented. It is simpler and easier to access the target detection material.

The source electrode 182, the drain electrode 184, the channel 186, and the gate electrodes 120 and 130 may be doped with a P-type material or may be doped with an N-type material.

The metal terminal 116 is formed of metal on the source electrode 182, the drain electrode 184, and the gate electrodes 120 and 130 for stable connection with a power source.

The nano-gap 140 between the gate electrodes 120 and 130 and the channel 186 is provided with a receiver 115 for detecting a target material.

When the source electrode 182, the drain electrode 184, the channel 186, and the gate electrodes 120 and 130 are doped with an N-type, the anode of the power source 192 is connected to the drain electrode 184 as shown in FIG. 3. The cathode of the power source 192 is connected to the source electrode 182, the cathode of the power source 193 is connected to the first gate electrode 120, and the cathode of the power source 192 is also connected to the second gate electrode 130. The cathode is connected.

In this connection, as the electrons are pushed by the field generated in the gate electrodes 120 and 130, a depletion layer is formed in the channel 186. At this time, if the voltages of the gate electrodes 120 and 130 are constantly adjusted, current flows through the channel 186. The relationship between the gate voltage and the current flowing through the channel is shown in FIG. 4.

Meanwhile, when the source electrode 182, the drain electrode 184, the channel 186, and the gate electrodes 120 and 130 are doped with a P type, an anode of the power source 191 is connected to the drain electrode 184, and the source A cathode of the power source 192 is connected to the electrode 182, an anode of the power source 193 is connected to the first gate electrode, and an anode of the power source 192 is also connected to the second gate electrode.

In this state, when the target material 117 is not located in the nanogap 140, a constant current according to the gate voltage flows through the channel as shown in the solid line of FIG. 4. If the target material 117 is located in the nanogap 140, the intensity of the field changes so that the current-voltage plot moves to the right or left. The direction of movement of the current-voltage diagram depends on the type of target material and the electrical properties. For this purpose, an ammeter for detection of current and a voltmeter for detection of voltage may be connected to the nanogap biosensor.

5 illustrates a drain current according to an initial gate voltage, a drain current according to a gate voltage in a state where a receptor is attached, and a drain according to a gate voltage in a state where a target material is attached in a nanogap sensor for detecting an AI antibody. A graph showing the currents respectively.

As shown in FIG. 5, it can be seen that when the receptor is attached to the initial current-voltage diagram, the current-voltage diagram moves to the right side, and the target substance moves to the right side when the avian influenza (AI) antibody is attached.

This change in the current-voltage diagram makes it easy to determine whether the target material is present. In addition, the nanogap sensor may be more easily manufactured by forming the source electrode 182, the drain electrode 184, the gate electrodes 120 and 130, and the channel 186 by doping one material.

In the above description of the preferred embodiment of the present invention, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

1A to 1J are flowcharts of steps of constructing a method of manufacturing a nanogap sensor according to an embodiment of the present invention.

2 is a perspective view illustrating a nanogap sensor according to an embodiment of the present invention.

3 is a diagram illustrating a state in which a power source is connected to the nanogap sensor according to an embodiment of the present invention.

Figure 4 is a graph showing the current and voltage diagram of the nanogap sensor according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: substrate 112: silicon layer

114: resist layer 115: receptor

116: metal terminal 117: target material

118: oxide film 120, 130: gate electrode

140: nanogap 182: source electrode

184: drain electrode 186: channel

Claims (21)

Source electrodes; Drain electrode; A channel connecting the source electrode and the drain electrode; And A gate electrode spaced apart from and adjacent to the channel; Including, The source electrode, the drain electrode, the channel, and the gate electrode is made of a silicon layer doped with the same type of material, And the source electrode, the drain electrode, the channel, and the gate electrode are doped with a P-type material. delete The method according to claim 1, The anode of the power source is connected to the drain electrode, the cathode of the power source is connected to the source electrode, the nano-gap sensor is connected to the anode of the power supply to the gate electrode. Source electrodes; Drain electrode; A channel connecting the source electrode and the drain electrode; And A gate electrode spaced apart from and adjacent to the channel; Including, The source electrode, the drain electrode, the channel, and the gate electrode is made of a silicon layer doped with the same type of material, And the source electrode, the drain electrode, the channel, and the gate electrode are doped with an N-type material. 5. The method of claim 4, The anode of the power source is connected to the drain electrode, the cathode of the power source is connected to the source electrode, the nano-gap sensor is connected to the cathode of the power source to the gate electrode. The method according to claim 1, And the source electrode, the drain electrode, the channel, and the gate electrode are doped with the same material. The method according to claim 1, The gate electrode is made of one or two or more nano-gap sensor spaced apart from the channel and the nano-gap between The method according to claim 1, And a nano gap sensor attached to the nano gap between the gate electrode and the channel to react with a material to be detected. The method according to claim 1, And a metal terminal attached to upper surfaces of the drain electrode, the source electrode, and the gate electrode. The method according to claim 1, The nanogap sensor having an oxide film formed on the drain electrode, the source electrode, and the gate electrode. The method according to claim 1, And the drain electrode, the source electrode, and the gate electrode have the same height. The method according to claim 1, The channel has a width of 10nm to 300nm nanogap sensor. The method according to claim 1, The channel has a length of 100nm to 50000nm nano-gap sensor. The nanogap sensor of claim 1, wherein the nanogap has a width of about 10 nm to about 300 nm. Forming a silicon layer on the substrate; A resist layer forming step of applying a resist layer on the silicon layer; A resist layer patterning step of forming a pattern in the resist layer; Patterning a silicon layer by etching the silicon layer to form a nanogap; A resist layer removing step of removing the resist layer; An impurity doping step of doping impurities entirely into the silicon layer; And Attaching a receptor in the nanogap to react with the substance to be detected; Nanogap sensor manufacturing method comprising a. The method of claim 15, The impurity is a method of manufacturing a nano-gap sensor consisting of a P-type material or N-type material. The method of claim 15, The patterning of the silicon layer may include forming a drain electrode and a source electrode, a channel connecting the drain electrode and the source electrode, and a gate electrode spaced apart from and adjacent to the channel. 18. The method of claim 17, Attaching a metal electrode to an upper surface of the drain electrode, the source electrode, and the gate electrode. The method of claim 15, The impurity doping step is performed after the resist layer removing step. The method of claim 15, The impurity doping step is performed after the silicon layer forming step. The method of claim 15, In the impurity doping step, when the nanogap is referred to as G1 (nm) and the dopant amount of the impurity is D1, the nanogap sensor having 0.01 * G1 * 1E13atoms / cm ³ ≤D1≤18E19-G1 * 8E17atoms / cm ³ Manufacturing method.

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