JP2013130409A - Micro nano-fluid analysis device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device structure, in a micro nano-fluid analysis device for analyzing DNA, in which measurement accuracy is improved by making movement in a height direction or a horizontal direction of DNA inside of a flow passage controllable and improving controllability for a height of the flow passage.SOLUTION: A micro nano-fluid analysis device comprises a conductive film provided on a substrate, a first electrode which applies a voltage to the conductive film, a channel part of which the top face from one side end face of a first insulating film provided on the conductive film to another side end face is opened and which becomes a flow passage for a solution, at least a pair of electrode terminals which are provided on both side faces of the channel part while being confronted to each other, and second and third electrodes which apply voltages to wiring connected to the pair of electrode terminals, respectively. When passing the solution through the channel part, a voltage is applied between the second electrode and the third electrode and an electric signal flowing between the second and third electrodes is measured via a specimen contained in the solution, thereby analyzing the specimen.

Description

  The present invention relates to a measurement technique using a micro / nanofluidic analysis device.

  As an approach for realizing a next-generation DNA sequencer, a measurement method using a nanopore device provided with a hole having the same size as that of DNA and electrodes on both sides thereof has attracted attention (Non-Patent Document 1). When DNA passes through the hole, the base sequence is to be deciphered by the change in the tunnel current flowing between the electrodes on both sides (FIG. 1A shows a simplified cross-sectional view and circuit diagram, and FIG. 1B shows a top view). Fig. 2 shows a conceptual diagram of data obtained by measurement). The feature of this method is that the base sequence can be analyzed electrically without labeling DNA, in other words, without using reagents such as enzymes and fluorescent dyes. Therefore, the process using the reagent can be reduced, and the analysis cost and reading throughput can be expected to be reduced.

  In the manufacture of nanopore devices, a method using a semiconductor substrate, a semiconductor material, and a semiconductor process has attracted attention because of its high mechanical strength (Non-Patent Document 2). As one of typical manufacturing methods, as described in Non-Patent Document 2, a thin insulating film region is provided on a semiconductor substrate, two electrodes are formed therein, and an electron beam is irradiated between the two electrodes. There is a method of forming pores. By controlling the energy, irradiation area, and current of the electron beam, pores of 10 nm or less can be formed.

Currently, the energy of an electron beam required for stable pore formation of 10 nm or less is 200 keV, the irradiation area is about 1 nm ² , and the current is about 10 ⁸ e / (nm ² · s). A TEM (transmission electron microscope) apparatus is used. It is used. In processing with a TEM apparatus, there is a limit to the size of a sample that can be carried into the apparatus, and it is usually difficult to simultaneously focus a beam at a plurality of locations. Therefore, for example, all chips on an 8-inch wafer cannot be simultaneously processed at once, and processing is performed by cutting out one chip at a time. Therefore, the throughput of device formation is reduced.

  In nanopore devices, in the future, it is considered that a plurality of electrodes having two pairs of gaps are stacked, and a signal is detected a plurality of times when a single DNA passes through the pore, thereby improving read accuracy. It is done. If a plurality of electrodes are stacked, the thickness of the membrane increases, and pore opening by electron beam irradiation becomes more difficult. It is also difficult to stack a plurality of electrodes having a gap of 10 nm or less with a matching accuracy of 10 nm or less.

  In order to avoid these problems, a nano-order flow path is provided on the substrate, two pairs of electrodes are provided on the side walls of the flow path, and the DNA base sequence passing through the flow path is determined by a tunnel current between the two pairs of electrodes. A method of detecting is conceivable. In patent document 1, the device by which two pairs of electrodes are arrange | positioned at the side wall of a flow path is disclosed. Also in Non-Patent Document 3, a channel device having a channel width of 45 nm, a width of 9 nm between two pairs of electrodes, and a height of 16 nm is formed. In this manufacturing method, a flow path pattern is formed on a substrate using nanoimprint lithography, and a flow path is dug by RIE etching. After that, a resist pattern on the narrow trench is formed by nanoimprint so as to be orthogonal to the flow path, and then metal is deposited obliquely with respect to the flow path side wall by using a two-stage oblique evaporation method. Then, lift-off creates an electrode pair that goes directly to the flow path. The two electrodes are not short-circuited by oblique deposition. Thereafter, the glass plate is crimped and the upper part of the flow path is covered.

JP 2006-258813 A

Johan Lagerqvist, et al., NANO LETTERS (2006) Vol. 6, No. 4 779-782 Brian C. Gierhart, et al., SENSORS AND ACTUATORS B 132 (2008) 593−600 Xiaogan Liang and Stephen Y. Chou NANOLETTERS (2008) Vol.8, No.5 1472-1476

  When DNA is migrated in a flow channel, if the depth of the flow channel is sufficiently deep with respect to the thickness of the DNA, the orientation of the DNA in the flow channel can take various arrangements as shown in FIG. 3B. it can. FIG. 3A shows a device cross-sectional view parallel to the flow path, and FIG. 3B shows DNA passing through the flow path. For example, in the case of an arrangement in which a plurality of bases are simultaneously positioned with respect to the electrode part as shown in FIG. In order to avoid this, ideally, as shown in FIG. 4, the height direction of DNA is required to be uniform at the time of measurement.

  The same can be said for the lateral direction when the width of the channel is sufficiently larger than the thickness of the DNA.

  As another problem, in the case of a device that is used by covering with glass or the like after forming the flow channel as in Non-Patent Document 3, the lid is bent into the flow channel portion when the lid is crimped, and the flow channel The controllability of the height becomes worse. Therefore, when forming a flow channel device of several nm, a process that does not require a lid is desired. Further, when a lid is necessary, it is necessary to improve the controllability of the pressure bonding of the lid by flattening the surface of the flow path device with almost no step.

  Accordingly, an object of the present invention is to provide a device structure that can control the movement in the height direction or the horizontal direction of DNA in a flow path, and that improves the controllability of the height of the flow path, and a method for manufacturing the device structure. It is.

In order to achieve the above object, the main components of the fluid analysis device and the manufacturing method thereof according to the present invention are as follows.
(1) A fluid analysis device that analyzes a sample contained in a solution by current measurement, and is provided on a conductive film provided on a substrate, a first electrode that applies a voltage to the conductive film, and a conductive film. In addition, a groove portion serving as a solution flow path having an upper surface extending from the first region to the second region of the first insulating film, at least a pair of electrode terminals provided opposite to both side surfaces of the groove portion, and a pair of electrodes A second and a third electrode for applying a voltage to the wiring connected to each of the terminals, and when passing the solution through the groove, a voltage is applied between the second electrode and the third electrode; The sample is analyzed by measuring an electric signal flowing between the second and third electrodes through the sample contained in the solution.
(2) A fluid analysis device for analyzing a sample contained in a solution by current measurement, wherein the substrate, a groove serving as a flow path for the solution provided on the substrate, and a groove on the upper surface of the groove in a direction intersecting the groove A conductive film provided, and a first electrode for applying a voltage to the conductive film. The groove portion is formed of an insulator on both side surfaces, the bottom surface is the substrate, and the top surface is formed of the conductive film. When passing the sample through the groove, a voltage is applied between the first electrode and the substrate, and an electric signal flowing between the first electrode and the substrate through the sample contained in the solution is measured. It is characterized by analyzing.
(3) A method of manufacturing a fluid analysis device including a flow path for flowing a sample contained in a solution and a wiring section for applying an electric field to the sample passing through the flow path, wherein the first conductive film is formed on the substrate. Depositing and forming a substrate electrode; forming a first insulating film on the substrate electrode; forming a first opening having a predetermined width in the first insulating film; and the first opening and the first insulation. A step of depositing a second conductive film on the film and embedding the second conductive film in the first opening using a planarization technique, and forming a predetermined width in a direction crossing the longitudinal direction of the wiring portion; Forming a flow path by opening the second opening having the first insulating film and forming a terminal portion of the wiring on a side surface of the flow path intersecting the wiring portion.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide a device structure that can control the movement of DNA in the height direction or the horizontal direction in the channel, and to improve the controllability of the channel height, and a method for manufacturing the device structure. It becomes. This can improve the detection accuracy and analysis accuracy of micro / nanofluidic devices that detect and analyze objects in solutions such as DNA, proteins, viruses, and bacteria.

Sectional drawing and a circuit diagram of a nanopore type | mold DNA sequencer. The top view of a nanopore type | mold DNA sequencer. The conceptual diagram of the signal obtained by a nanopore type | mold DNA sequencer. The overhead view which shows a flow path with a detection electrode. The figure which shows the DNA which flows through the flow path with a detection electrode, and a flow path. The figure which shows the DNA which flows through the flow path with a detection electrode, and a flow path. Sectional drawing of the process explaining the manufacturing method of Example 1. FIG. The top view of the process explaining the manufacturing method of Example 1. FIG. Sectional drawing of the process explaining the manufacturing method of Example 1. FIG. The top view of the process explaining the manufacturing method of Example 1. FIG. Sectional drawing of the process explaining the manufacturing method of Example 1. FIG. 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  Components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof is omitted as much as possible. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The device structures and materials described in the examples are examples for embodying the idea of the present invention, and do not strictly specify materials, dimensions, and the like.

  In order to align the position in the height direction of DNA migrating in the flow path, a structure is provided in which electrodes are provided on the substrate as shown in FIGS. 14A and 14B. The device structures and materials described in this embodiment and other embodiments are examples for embodying the idea of the present invention, and do not strictly specify materials, dimensions, and the like.

  14A is a cross-sectional view of the device of this example, FIG. 14B is a top view, and FIGS. 14A a) and b) show the AA ′ cross-section and BB ′ cross-section of FIG. 14B, respectively. Yes. The A-A ′ cross section is a cross section along the flow path, and the B-B ′ cross section is a cross section perpendicular to the flow path and along the two pairs of electrodes. Reference numeral 100 in the drawing is, for example, a Si substrate, reference numeral 102 is an insulating film, for example, a silicon nitride film (hereinafter abbreviated as SiN film), and reference numeral 104 is made of a conductive material, for example, Au, Pt, Cr. , Ta, Ti, TiN, W, etc. Reference numeral 106 is made of a conductive material, such as Au, Pt, Cr, Ta, Ti, TiN, or W. Reference numeral 104 denotes a detection electrode for detecting a base of DNA, and reference numeral 106 denotes a substrate side electrode for applying an electric field to the flow path with the insulating film interposed therebetween.

  In this embodiment, when viewed in the CC ′ cross section, there is ideally no step on the surface between the pair of detection electrodes 104 and the SiN film 102 in contact with the sidewall of the detection electrode 104, or Minimal. Therefore, when glass or the like is pressure-bonded to the upper part of the flow path and the lid 118 is pressed, the pressure bonding is facilitated, and the formation of a cavity other than the flow path part due to the step or the variation in the height direction in the flow path due to the step. It is suppressed and the improvement of the conveyance accuracy and detection accuracy of the solution can be realized.

  DNA is usually managed in an aqueous KCl solution. In order to transport DNA into the channel, the channel is filled with a KCl aqueous solution containing DNA, electrodes are immersed in the solution at the inlet and outlet of the channel, and a voltage difference is provided, so that the DNA is introduced into the channel. It can be transported from the direction to the exit direction. Since DNA has a negative charge, it can be electrophoresed. When DNA is migrated in the flow path, a positive voltage is applied to the substrate-side electrode 106 with respect to the voltage applied to the flow path entrance, so that the DNA can be drawn toward the bottom of the flow path. It is possible to make DNA take an arrangement that is constant in the height direction as shown in FIG. 15A.

  FIG. 15A is a view of a part of the A-A ′ cross section viewed from an oblique direction. Reference numeral 200 in the figure is a schematic diagram of DNA, and each square constituting it is a schematic diagram of one base (201) of DNA. Similarly, by applying a negative voltage to the substrate side electrode 106 with respect to the voltage applied to the channel inlet, DNA can be pushed to the upper part of the channel (side covered with glass or the like), As shown in FIG. 15B, the DNA can be arranged so as to be constant in the height direction.

  An example of the manufacturing method of the micro / nanofluidic device is shown in the cross-sectional views of FIGS. At the same time, top views corresponding to the cross-sectional views are shown in FIGS. 5B to 14B.

  First, as shown in FIG. 5A, a substrate side electrode 106 is formed on a Si substrate 100, and a SiN film 102 is formed thereon. The substrate-side electrode 106 is a conductive material, and examples thereof include Au, Pt, Cr, Ta, Ti, TiN, and W. Thereafter, the SiN film 102 is etched using a resist as a mask to form a groove in a portion where a detection electrode is to be disposed later. A thick portion in the groove in FIG. 5B is a device for facilitating contact with the electrode. The substrate-side electrode 106 may be disposed only in the vicinity of the lower portion of the portion that will later become a flow path. When the substrate-side electrode 106 is disposed only near the lower portion of the portion that becomes the flow path, an insulating film is formed on the Si substrate 100, and a pattern of the substrate-side electrode 106 is formed thereon, so that the electrode is applied when voltage is applied. Only the part can be locally applied with voltage. Further, a high-concentration Si substrate may be used as the substrate-side electrode 106 as it is. The width of the groove to be patterned by etching SiN is determined so that the groove width finally determined in the next process (see FIGS. 6A and 6B) is optimum.

  Next, in the process shown in FIGS. 6A and 6B, the SiN film 102 is deposited to reduce the width and depth of the groove. The final dimensions after reducing the width and depth of the groove are such that the width is as close as possible to the size of one base of DNA in order to detect the base of the DNA, and the depth is preferably as much as possible. It forms so that it may become a value close | similar to the magnitude | size of 1 base of.

  Next, as shown in the steps shown in FIGS. 7A and 7B, an electrode material that will later become the detection electrode 104 is deposited. The detection electrode 104 is made of a conductive material, and examples thereof include materials such as Au, Pt, Cr, Ta, Ti, TiN, and W.

  Subsequently, as shown in the steps shown in FIGS. 8A and 8B, a flat surface made of a conductive material and an insulating film is formed by polishing to the SiN surface below the metal by a flattening process such as CMP. Thus, by forming the wiring of the conductive material in the embedded type, it is advantageous as described above when the channel is covered later by pressure bonding of the glass plate or the like. In the case where the wiring is not buried as described above, a step is generated between the wiring and the surrounding insulating film by the height of the wiring. The step causes the formation of cavities other than the flow channel part or the variation in the height direction in the flow channel due to the step when the lid is capped or after the lid is capped. One of the features of this manufacturing method and this device is that the level difference between the wiring of the detection electrode and the surrounding insulating film is not more than the height of the wiring of the detection electrode and is almost flat.

  Further, in order to further improve the flatness, after forming a flat surface made of a conductive material and an insulating film as shown in FIGS. 8A and 8B, an insulating film is further deposited to perform CMP without exposing the electrode surface. Flattening may be performed by a flattening process such as. Flatness is improved over flattening by exposing different kinds of materials. In this case, if the subsequent processes are performed according to the present embodiment, the height of the flow path becomes higher than the height of the counter electrode when the device is completed, and an insulating film exists above the counter electrode. In that case, in the DNA measurement, if a voltage is applied to the substrate side electrode and the DNA is drawn toward the substrate side, the DNA can be accurately placed between the opposing electrodes.

Next, in the steps shown in FIGS. 9A and 9B, a silicon oxide film (hereinafter abbreviated as SiO ₂ film) 101 is deposited and patterned using a resist as a mask, thereby forming a groove in a portion that later becomes a flow path pattern. . A thick portion in the groove shown in FIG. 9B is a device for facilitating contact with the flow path. Further, this portion may be deeply dug in order to facilitate solution injection. The width of the groove to be patterned by etching SiO ₂ 101 is determined so that the width finally determined in the subsequent steps (ie, FIGS. 10A and 10B, FIGS. 11A and 11B) is optimal.

Further, in the step shown in FIGS. 10A and 10B, the SiO ₂ film 101 is deposited to reduce the width of the groove. The final dimension after reducing the width of the groove is as close as possible to the thickness of the DNA from the viewpoint of controlling the direction of the DNA when transferring the DNA in order to determine the width of the channel. To form.

Subsequently, in the step shown in FIG. 11, the surface of the detection electrode 104 is exposed by etching back the SiO ₂ film 101 by the thickness deposited in FIGS. 10A and 10B. At the time of etch back, the SiO ₂ film remains on the side wall of the groove formed in FIGS. 9A and 9B, thereby narrowing the groove. At this time, in order to determine the width of the channel, the width of the groove is preferably set to a value equivalent to the thickness of the DNA from the viewpoint of controlling the direction of the DNA during DNA transfer.

  Further, in the process shown in FIGS. 12A and 12B, the flow path for transporting DNA is formed by etching the detection electrode and the SiN film by the thickness of the detection electrode.

Next, in the process shown in FIGS. 13A and 13B, the SiO ₂ film is selectively etched and removed using HF or the like.

  Next, in the process shown in FIGS. 14A and 14B, a resist is patterned, and a contact hole to the substrate-side electrode 106 is formed using the resist as a mask.

  Thereafter, a plate such as glass or other insulating film is pressure-bonded to the channel portion on the surface of the device to cover the upper portion of the channel. As an example, the lid covers the inlet portion and outlet portion of the solution and the flow passage portion, and the hole corresponding to the inlet portion and outlet portion of the solution is made later, so that it also has the outlet portion and outlet portion of the solution. Can be formed.

  In addition, it can also be used as detectors, such as biomolecules other than DNA, a virus, bacteria, by changing the flow path width and electrode width of this device according to a target object.

  As one of the features of this manufacturing method, when creating the final ultrafine channels and electrodes, first, grooves are formed in the mask with a pattern that can guarantee accurate dimensions (width) with the current lithography technology. It is possible to narrow the width of the groove by using a film deposition method that can be controlled conformally and precisely on the order of nanometers. A film deposition method that can control the film thickness at a conformal and atomic layer level includes, for example, a technique such as ALD (Atomic Layer deposition), and other known techniques that have been developed for a long time in semiconductor device development. There are many. This makes it possible to form a flow path having a width close to the size of DNA.

  Regarding the control in the depth direction, as described above, the reliability of the detection signal can be improved by controlling the height direction of the target DNA by applying an electric field to the flow path by the substrate-side electrode 106. I can do it. Since the electrode used for height direction control and the detection electrode 104 are independent, the optimum voltage in the height direction and the optimum voltage for detection can be divided. For example, the voltage applied to the solution near the flow path inlet is 0 V, the voltage applied to the solution near the flow path outlet is Vout> 0 V, the voltage of the substrate side electrode 104 is Vsub> 0 V, and one of the detection electrodes 104 The device is operated with a positive voltage and the other negative voltage.

  From the viewpoint of controlling the solution flow, the width and depth of the flow path part other than the detection part where the counter electrode is present may be designed widely.

  As in Example 1, there is no substrate step between the pair of detection electrodes 104 and the SiN film 102 in contact with the side wall of the detection electrode 104, or a substrate electrode that can apply an electric field to the flow path. Here is another example of the manufacturing method for the installed device.

First, in steps shown in FIGS. 16A and 16B, a substrate side electrode 106 is formed on the Si substrate 100, a SiN film 102 is deposited thereon, and a SiO ₂ film 101 is formed thereon. Thereafter, the SiO ₂ film is patterned using a resist as a mask.

  Next, in the steps shown in FIGS. 17A and 17B, an electrode material that will later become a pair of detection electrodes 104 is deposited. The detection electrode 104 is a conductive material, and examples thereof include Au, Pt, Cr, Ta, Ti, TiN, and W. Since the thickness of the conductive material to be deposited is substantially equal to the thickness of the detection electrode, it is preferably formed to have a thickness equivalent to one base of DNA.

Next, in the process shown in FIGS. 18A and 18B, a resist pattern 103 is formed so as to cover the corners of the patterned SiO ₂ film portion.

Further, in the process shown in FIGS. 19A and 19B, the electrode material is etched back by the thickness deposited in FIGS. 17A and 17B to form a side wall of the conductive material on the SiO ₂ side wall. Thereafter, the resist is removed. Since the width of the side wall becomes the width of the detection electrode, in order to detect single base with high accuracy, it is formed to have a width equivalent to one base of DNA.

Next, in the steps shown in FIGS. 20A and 20B, unnecessary portions of the SiO ₂ film and the conductive material are removed by an etching process.

Subsequently, in the step shown in FIGS. 21A and 21B, a SiO ₂ film is deposited on the entire surface.

  Next, in the step shown in FIGS. 22A and 22B, the surface of the electrode material is ground and flattened by a flattening process such as CMP as shown in the drawing. At this time, as shown in the drawing, an insulating film may remain on the upper portion of the thin portion of the conductive material wiring (the portion where the flow path crosses later). When the device is completed, the height of the flow path becomes higher than the height of the counter electrode, and there is an insulating film above the counter electrode. However, when measuring DNA, a voltage is applied to the substrate side electrode to place the DNA on the substrate. When pulled to the side, DNA can be placed between the opposing electrodes. Further, by not cutting until a thin portion of the wiring of the conductive material is exposed, the surface flatness is improved as compared with the case where the wiring is exposed. If flatness is improved, when the upper part of the flow path is covered later by pressure bonding with a glass plate or the like, as described in Example 1, the controllability is improved. Formation of cavities can be avoided.

  Next, in the process shown in FIGS. 23A and 23B, an amorphous silicon (a-Si) film 105 is deposited and then patterned so as to intersect the electrode pattern of the sidewall as shown in the figure.

  Further, in the step shown in FIGS. 24A and 24B, the SiN film 102 is deposited. Since the film thickness of this SiN film will be a film thickness that determines the width of the channel later, it is formed to have a film thickness equivalent to the thickness of the DNA from the viewpoint of improving the direction control of the DNA during DNA transport. . Thereafter, a resist pattern 103 is formed so as to cover the corners of the patterned a-Si film.

  Next, in the step shown in FIGS. 25A and 25B, the SiN film 102 is etched back by the thickness deposited in FIGS. 24A and B, thereby forming SiN sidewalls on the a-Si sidewalls. Since the side wall film thickness is a film thickness that determines the width of the channel later, it is formed so as to have a film thickness equivalent to the thickness of DNA from the viewpoint of improving the direction control of DNA during DNA transport.

  Next, in the step shown in FIGS. 26A and 26B, unnecessary portions of the SiN film and the a-Si film are removed by etching using a resist as a mask as shown in the figure.

  Further, in the process shown in FIGS. 27A and 27B, an a-Si film is deposited on the entire surface.

  Subsequently, in FIGS. 28A and 28B, the top surface of the SiN sidewall is cut and planarized by a planarization process such as CMP as shown in the figure.

  Next, in the step shown in FIGS. 29A and 29B, SiN is removed by wet etching using phosphoric acid or the like, or other etching selective to the a-Si film.

Next, in the step shown in FIGS. 30A and 30B, the SiO ₂ film is removed by etching using the a-Si film as a mask.

  Further, in the step shown in FIGS. 31A and 31B, the surface of the detection electrode is ground and planarized by a planarization process such as CMP.

Next, in the steps shown in FIGS. 32A and 32B, as shown in FIG. 32B, SiO ₂ is etched to increase the entrance and exit areas of the flow path, and to make contact with the flow path easier. . By digging deeper into the part, solution injection can be further facilitated.

  Further, in the process shown in FIGS. 33A and 33B, as shown in FIG. 33B, a resist pattern is formed with a hole serving as a contact (pad) of the detection electrode.

  Next, in the process shown in FIGS. 34A and 34B, a conductive material for the contact (pad) for the detection electrode is deposited, and then the resist is lifted off to form an electrode contact as shown in the figure. After etching the surface a little with the resist pattern as a mask, a conductive material for contacts (pads) may be deposited and lifted off.

  Finally, in the step shown in FIGS. 35A and 35B, the contact to the substrate electrode is patterned using a resist as a mask.

  Thereafter, a plate such as glass or other insulating film is pressure-bonded to the channel portion on the surface of the device to cover the upper portion of the channel. As an example, the lid covers the inlet portion and outlet portion of the solution and the flow passage portion, and the hole corresponding to the inlet portion and outlet portion of the solution is made later, so that it also has the outlet portion and outlet portion of the solution. Can be formed.

  This production method is characterized in that a sidewall process is used to form the flow path. In principle, the sidewall process can form sidewalls as thin as the deposited film thickness. The thin film deposition technique in the current semiconductor process can be controlled to 1 nm or less, so that a side wall comparable to the thickness of DNA can be formed, and a flow path with a fine width can be formed. Therefore, variation in the arrangement of DNA in the horizontal direction can be made. Control of the lateral arrangement of the DNA improves the reliability of the detection signal. Further, since the detection electrode is also formed by using a sidewall process, an electrode having a width close to the size of one base of DNA can be formed. As the electrode width approaches the size of one base of DNA, the influence on the detection signal by the base other than the reading target adjacent to the reading target is reduced, and the resolution of the detection signal is improved.

  Furthermore, as in Example 1, the reliability of the detection signal can be improved by applying an electric field to the flow path by the substrate-side electrode to control the height direction of the target DNA. Since the electrode used for the height direction control and the detection electrode are independent, the optimum voltage in the height direction and the optimum voltage for detection can be divided.

In addition, it can also be used as detectors, such as biomolecules other than DNA, a virus, and bacteria, by changing the flow path width of this device according to a target object.
Further, from the viewpoint of controlling the solution flow, the width and depth of the flow path part other than the detection part where the counter electrode exists may be designed to be wide.

  In this example, a manufacturing method and a structure of a flow channel device in which the diameter of the flow channel can be controlled with the same degree as the thickness of DNA and the upper part of the flow channel does not need to be covered with a glass plate or the like are shown. If it is not necessary to cover the upper part of the flow path with a glass plate, the device manufacturing process is simplified, and problems such as non-uniformity in the width and depth of the flow path that occur in the glass plate crimping process can be resolved. I can do it.

  FIG. 57A shows a cross-sectional view of the device structure shown in this embodiment, and FIG. 57B shows a top view thereof. On the Si substrate 100, a flow path having both side walls covered with the SiN film 102 is formed. In addition to the region covered with the SiN film 102, the detection electrode 104 is disposed on the upper portion of the flow path so as to intersect the flow path. The detection electrode 104 is provided with a region that can contact a portion away from the flow path. The channel region is also provided with an inlet and an outlet that are large enough to be injected into the solution in a region away from the detection electrode. In the measurement, a voltage is applied between the detection electrode 104 and the Si substrate 100, and a tunnel current flows between the detection electrode 104 and the Si substrate 100. When DNA passes between the detection electrode 104 and the Si substrate 100, the base sequence of the DNA is read out by a change in the tunnel current flowing between the detection electrode 104 and the Si substrate 100. Alternatively, there are a method of reading by a change in capacitance between the detection electrode 104 and the Si substrate 100, a method of reading by detecting a difference in surface charge state of the detection electrode 104, and the like. Below, the example of the manufacturing method of the device of a present Example is shown along a figure.

First, in the process shown in FIGS. 36A and 36B, an SiO ₂ film 101 is deposited on the Si substrate 100 and patterned as shown in the figure using a resist as a mask. Since the Si substrate also serves as a lower electrode, a high concentration substrate is preferable.

  Next, in a step shown in FIGS. 37A and 37B, a SiN film 102 is deposited on the entire surface. Since the SiN film has a film thickness that determines the width of the channel later, it is formed to have a value as close to the thickness of the DNA as possible from the viewpoint of controlling the DNA movement direction.

Next, in the steps shown in FIGS. 38A and 38B, a resist pattern is formed so as to cover the corners of the patterned SiO ₂ film.

  Further, in the step shown in FIGS. 39A and 39B, the side wall is formed by etching back the film thickness of the deposited SiN film 102. Since the thickness of the sidewall is a thickness that will later determine the width of the channel, it is formed so as to have a value as close as possible to the thickness of DNA from the viewpoint of controlling the direction of DNA movement.

Next, in the steps shown in FIGS. 40A and 40B, unnecessary portions of the SiO ₂ film and the SiN film are removed by etching.

Next, in the steps shown in FIGS. 41A and 41B, the SiO ₂ film is etched to form SiN sidewall lines.

  Next, in the steps shown in FIGS. 42A and 42B, the Si substrate is etched using the SiN film as a mask.

  Subsequently, in the process shown in FIGS. 43A and 43B, a SiN film is deposited on the entire surface.

  Next, in the process shown in FIGS. 44A and 44B, the surface of the Si substrate is cut and planarized by a planarization process such as CMP.

  Further, in the process shown in FIGS. 45A and 45B, a conductive material to be the detection electrode 104 is deposited. Examples of the detection electrode 104 include materials such as Au and Pt. A material having strong oxidation resistance is preferable.

Next, in a process shown in FIGS. 46A and 46B, an SiO ₂ film 101 is deposited and patterned using a resist as a mask to form a pattern as shown in the figure.

  Next, in a step shown in FIGS. 47A and 47B, a SiN film 102 is deposited on the entire surface. Since this film thickness will later be a film thickness that determines the width of the detection electrode, it is formed so as to have a value as close as possible to a film thickness close to one base of DNA from the viewpoint of improving detection accuracy.

Next, in the process shown in FIGS. 48A and 48B, a resist pattern 103 is formed so as to cover the corners of the patterned SiO ₂ film.

  Further, in the step shown in FIGS. 49A and 49B, the SiN film 102 is etched back as much as the deposited thickness to form sidewalls. Since this film thickness will later be a film thickness that determines the width of the detection electrode, it is formed so as to have a value as close as possible to a film thickness close to one base of DNA from the viewpoint of improving detection accuracy.

Next, in the steps shown in FIGS. 50A and 50B, unnecessary portions of the detection electrode and the SiO ₂ film are removed by etching.

Next, in the steps shown in FIGS. 51A and 51B, the SiN sidewall lines are formed by etching the SiO ₂ film.

  Next, in the steps shown in FIGS. 52A and 52B, the detection electrode material is etched using the SiN film as a mask.

  Next, in the steps shown in FIGS. 53A and 53B, the Si substrate is oxidized by an oxidation process. Since this oxide film thickness determines the depth of the flow path, it is formed so as to have a value equivalent to the film thickness as close as possible to the thickness of DNA from the viewpoint of improving detection accuracy and improving DNA motion control.

As shown in the figure, the oxidation amount of the Si substrate below the detection electrode is smaller than that of the Si substrate other than the detection electrode lower portion because the oxidation amount is masked by the detection electrode. Therefore, the oxidation amount in the lower part of the detection electrode is formed to be a value equivalent to the film thickness close to the thickness of DNA. Further, during this oxidation, the amount of oxidation of the SiN film and the oxidation-resistant SiO ₂ 101 is very small. Therefore, by oxidizing the Si substrate and then performing light etching with diluted hydrofluoric acid, the SiO ₂ film on the Si substrate, the SiN film, and the oxide film of the conductive material can be selectively removed.

  Next, in the steps shown in FIGS. 54A and 54B, after the SiN film 102 is deposited, the SiN surface is flattened by a flattening process such as CMP.

  Further, in the steps shown in FIGS. 55A and 55B, the contact portion for the detection electrode is opened by etching using a resist as a mask. Thereafter, a contact is formed by embedding a conductive material.

  Next, in the steps shown in FIGS. 56A and 56B, the inlet and outlet portions of the flow channel portion are formed by etching SiN, and contacts to the flow channel portion are formed.

Finally, in the step shown in FIGS. 57A and 57B, the SiO ₂ film on the Si substrate is etched by selective wet etching and dry etching such as HF to form the flow path 203.

  This production method is characterized in that a sidewall process is used to form the flow path. In principle, the sidewall process can form sidewalls as thin as the deposited film thickness. A thin film deposition technique in a semiconductor process can be controlled to 1 nm or less, and therefore, a side wall comparable to the thickness of DNA can be formed, and a channel having a fine width can be formed. Thereby, the variation in the horizontal arrangement of the DNA in the flow path is reduced, and the reliability of the detection signal is improved. Further, in order to determine the depth of the flow path, a manufacturing method is employed in which the Si substrate is oxidized and selectively removed later by etching. As described above, the thin film formation technique in the semiconductor process can be controlled to 1 nm or less, and therefore, a flow path having an extremely shallow depth can be formed. Therefore, it is superior in controlling the height direction of DNA.

  Since the detection electrode is also formed using a sidewall process, an electrode having a width close to the size of one base of DNA can be formed. As the electrode width approaches the size of one base of DNA, the influence on the detection signal by the base other than the reading target adjacent to the reading target is reduced, and the resolution of the detection signal is improved.

  In addition, since the upper part of the flow path is covered with an insulating film, it is not necessary to cover it with a glass plate or the like, which simplifies the device manufacturing process and reduces the width and depth of the flow path caused by the glass plate pressing process. Problems such as uniformity can be solved.

  In this manufacturing method, the depth of the flow path other than the lower part of the detection electrode is deeper than the depth of the lower part of the detection electrode. For this reason, the DNA can be transported smoothly except for the detecting section because the cross-sectional area of the channel is large.

  As another manufacturing method, after the steps shown in FIGS. 44A and 44B, as shown in FIGS. 58A and 58B, the Si substrate may be oxidized by a thickness close to the thickness of the DNA. By doing so, the Si substrate is already oxidized as shown in FIGS. 59A and B in the process of FIGS. 52A and 52B. Therefore, there is no need for oxidation at this point. Therefore, there is no need to worry about the surface oxidation of the detection electrode. Therefore, even if a material having low oxidation resistance is used for the detection electrode, the range of material selection can be expanded without oxidizing the detection electrode. Therefore, for example, by selecting a conductive material used in the semiconductor process of the conventional CMOS process, the affinity with the conventional CMOS process and the compatibility with the conventional semiconductor process can be improved, and the integration with the integrated circuit is facilitated. Eventually, the completed drawing is as shown in FIGS. 60A and 60B.

  42A and 42B, the Si wall forming the flow path portion is formed by first forming a wide Si wall by etching, oxidizing it, and washing with HF, thereby forming a narrow Si wall. It may be formed. The system of thin film formation technology in semiconductor processes can be controlled to 1 nm or less.

  Further, in this device, there are not detection electrodes separated on both sides across the flow path, and wiring connected to the upper part of the flow path is arranged so as to straddle the flow path. Therefore, in this embodiment, the pads are provided on both sides of the flow path, but only one side may be used, which is advantageous for reducing the area of the device.

  Further, as a feature of this device, the substrate 100 under the flow path is dug into a convex shape with a width approximately equal to the width of the flow path, and the periphery thereof is filled with an insulating film 102. Therefore, a leakage current other than the current to be detected flowing from the substrate to the detection electrode 104 (or from the detection electrode to the substrate) in the flow path, that is, the flow path from the substrate to the detection electrode (or from the detection electrode to the substrate) Leakage current that flows through other than the part can be suppressed.

  Also, as an example of operation, by applying a positive voltage to the Si substrate, a negative voltage to the detection electrode, 0V or a negative voltage to the solution near the inlet of the flow path, and a positive voltage to the solution near the outlet, the DNA is very shallow. In this, it can move in the flow path while being drawn closer to the substrate side. Therefore, the reliability of the signal obtained between the detection electrode and the substrate is improved because the movement in the height direction is very controlled. That is, the Si substrate also serves as one side of the signal detection electrode, and at the same time controls the height direction of the DNA. Further, since the substrate side electrode is not provided separately, it is advantageous for reducing the device area.

In addition, it can also be used as detectors, such as biomolecules other than DNA, a virus, and bacteria, by changing the flow-path width | variety and electrode width of this device according to a target object.
From the viewpoint of controlling the solution flow, the width and depth of the flow path part other than the detection part where the counter electrode is present may be designed widely.

  A device manufacturing method and structure capable of detecting DNA with a tunnel current flowing between the Si substrate 100 and the detection electrode 104 will be described.

First, in a step shown in FIG. 61, a SiO ₂ film 101 is formed on a Si substrate 100, and a SiN film is deposited on the SiO ₂ film 101 and patterned. Since the Si substrate is also used as an electrode, a high concentration is preferable.

  Next, in the step shown in FIG. 62, a conductive material to be a detection electrode is deposited and etched back by the deposited film thickness, thereby forming a sidewall of the detection electrode. Since the film thickness of the sidewall is a film thickness that will later determine the width of the detection electrode, it is formed so as to be as much as possible with one base of DNA from the viewpoint of improving detection accuracy.

  Next, in a step shown in FIG. 63, a SiN film is deposited and the surface is flattened by a flattening process such as CMP.

Next, in the step shown in FIG. 64, the wafer is cleaved so that the cross section shown in the drawing appears, and then the oxide film is etched using a wet etch such as HF to form the flow path portion 203. Thereafter, the channel portion of the cleavage plane is covered with a glass plate or the like to form a channel.
The tunnel current flows between the detection electrode 104 and the substrate and detects DNA passing through the flow path.

In this process, the film thickness of the SiO ₂ film 101 corresponds to the width of the flow path, and the receding amount of the SiO ₂ film by HF etching after cleaving the wafer corresponds to the depth of the flow path. For this reason, the SiO ₂ film 101 is formed to have a thickness equivalent to the thickness of DNA. Further, the amount of receding of the SiO ₂ film by HF etching is formed to be approximately the same as the thickness of DNA.

  In this process, the number of process steps is very small and simple, and the width and depth of the flow path use an oxidation process matured in the conventional semiconductor process or an etching process using HF, etc., so that the control is performed in units of 1 nm. Is possible. The oxidation process can control the film thickness to 1 nm or less, and the HF etching can also control the film thickness to 1 nm or less. Therefore, since a flow path corresponding to a DNA thickness of about 2 nm or less can be formed, movements other than the DNA traveling direction (direction along the flow path) can be almost eliminated, and detection signal reliability is improved. Can be made. Since the detection electrode is also formed using a sidewall process, an electrode having a width close to the size of one base of DNA can be formed. As the electrode width approaches the size of one base of DNA, the influence on the detection signal by the base other than the reading target adjacent to the reading target is reduced, and the resolution of the detection signal is improved. In addition, it can also be used as detectors, such as biomolecules other than DNA, a virus, bacteria, by changing the flow path width and electrode width of this device according to a target object.

  From the viewpoint of controlling the solution flow, the width and depth of the flow path part other than the detection part where the counter electrode is present may be designed widely.

  In this embodiment, a device structure including a substrate-side electrode 106 and not requiring a lid on the upper part of the flow path is shown. 69A and 69B show the device structure. A substrate-side electrode 106 is provided on the Si substrate 100, a SiN film 102 is provided thereon, and a flow path and a counter electrode are disposed thereon. There is a SiN film 102 on the channel and the counter electrode.

  An example of a device manufacturing method is shown in FIGS. 65A and B to FIGS. 69A and 69B. In each figure, A is a cross-sectional view, and B is a top view. In addition, this manufacturing method is an example to the last, and is not limited to this.

First, in the process shown in FIGS. 65A and 65B, after the processes shown in FIGS. 5A and 12B and FIGS. 12A and 12B, the SiO ₂ film 101 is deposited, and the planarization and etching process by CMP is used. , B are formed.

  Next, in a step shown in FIGS. 66A and 66B, a SiN film is deposited.

  Next, in the steps shown in FIGS. 67A and 67B, the resist is patterned, using the resist as a mask, a contact hole is formed for conduction to the detection electrode, and a metal material is embedded.

  Further, in the process shown in FIGS. 68A and 68B, the resist is patterned, and a contact hole to the substrate side electrode is formed using the resist as a mask.

  Finally, in the steps shown in FIGS. 69A and 69B, the oxide film is etched by selective wet etching and dry etching such as HF to form a flow path.

  The process is more complicated than in Example 1, but according to this device, the reliability of the detection signal is improved by controlling the height direction of the target DNA by applying an electric field to the flow path by the substrate side electrode. Can be improved. Since the electrode used for position / direction control and the detection electrode are independent, the optimum voltage in the height direction and the optimum voltage for detection can be divided.

  In addition, since the upper part of the channel is covered with an insulating film, there is no need to cover it with a glass plate or the like, and problems such as non-uniformity in the channel width and depth that occur in the process of crimping the lid are eliminated. I can do it.

  In addition to controlling the height direction of DNA, a device that can be controlled by an electric field in the lateral direction is shown. The device structure and material to be described are examples for embodying the idea of the present invention, and the material and dimensions are not strictly specified. 70A is a cross-sectional view of the device of this example, FIG. 70B is a top view, and FIGS. 70A a and b show cross sections AA ′ and BB ′ of FIG. 70B, respectively. It is. The A-A ′ cross section is a cross section along the flow path, and the B-B ′ cross section is a cross section perpendicular to the flow path and along the two pairs of electrodes.

  Reference numeral 100 in the drawing is, for example, a Si substrate, reference numeral 102 is an insulating film, for example, a SiN film, and the detection electrode 104 is made of a conductive material. For example, Au, Pt, Cr, Ta, Ti, TiN, W Etc. The substrate side electrode portion 106 is made of a conductive material, and examples thereof include Au, Pt, Cr, Ta, Ti, TiN, and W. Reference numeral 107 denotes a DNA lateral direction control electrode, and examples thereof include materials such as Au, Pt, Cr, Ta, Ti, TiN, and W. In this embodiment, when viewed in the CC ′ cross section, the detection electrode 104, the DNA lateral control electrode 107, and the SiN film 102 in contact with the side walls of the detection electrode 104 and the DNA lateral control electrode 107 are interposed. Ideally, the surface has no step or is minimal. Therefore, when glass is crimped on the upper part of the flow path and capped, it is easier to crimp, and the formation of cavities other than the flow path due to the step and the variation in the height direction in the flow path due to the step are suppressed. In addition, it is possible to improve the solution conveyance accuracy and detection accuracy.

  For example, when a positive voltage is applied to one electrode of the lateral control electrode 107 and a negative voltage is applied to the other electrode across the flow channel, the DNA is attracted to the positive voltage applied side of the flow channel. 71A and 71B are top views of flow paths near the detection electrodes. As shown in FIG. 71A, when there is no DNA lateral control electrode or when an electric field is not applied by the DNA lateral control electrode and the flow channel width is sufficiently thicker than DNA, DNA moves laterally ( (Denoted by arrows in the figure). In this case, the detected signal varies depending on whether the DNA passes near the center of the flow path or the end of the flow path. On the other hand, as shown in FIG. 71B, by applying an electric field by the DNA lateral control electrode, when DNA is pushed in the direction of the wall on one side, variations in signals obtained through the detection electrode pairs can be reduced. Therefore, the reliability of the detection signal can be greatly improved by controlling the height and the lateral direction by the DNA lateral direction control electrode 107 and the substrate side electrode 106.

  Further, by applying a negative voltage having the same value to both sides of the DNA lateral direction control electrode 107, the DNA can be arranged at the center of the flow path in the lateral direction. Even in this case, variation in the arrangement of DNA in the horizontal direction can be reduced, and the reliability of the detection signal can be improved.

  Between the DNA lateral direction control electrode 107 and the flow path, there exists a SiN film 102 for preventing leakage between the electrodes. An insulating film for preventing leakage also exists between the detection electrode 104 and the DNA lateral control electrode 107. Since there is an insulating film for preventing leakage between the detection electrode 104 and the DNA lateral control electrode 107, the effect of the lateral control electric field between the counter electrodes as detection portions is weakened. For this reason, it is preferable to make the insulating film thickness as thin as possible in a range where leakage can be prevented.

  There is no substrate-side electrode under the solution inlet and outlet (112 in FIG. 72A), which has a large area for injecting the solution, and under the fine channel section with the detection electrode (113). 1 shows a device provided with a substrate-side electrode 106.

  72A-C are cross-sectional views along the flow path. FIG. 72A shows a case where the substrate side electrode is on the entire surface, where reference numeral 111 in the figure indicates the direction of force due to the negative charge and the electric field received by the DNA, and reference numeral 112 indicates a wide area that serves as an inlet or outlet for the solution. It is an arrow and the code | symbol 113 is a fine flow path part provided with the detection part. Reference numeral 114 denotes an electrode bar for creating an electric field for migrating DNA. The figure shows the negative charge and the force that DNA receives when a positive voltage is applied to the electrode rod immersed in the channel inlet, a positive voltage is applied to the electrode rod immersed in the channel outlet, and a positive voltage is applied to the substrate side electrode. An example of orientation is shown. In the case of FIG. 72A, there is a possibility that the direction of the force due to the electric field does not go to the exit direction, or there is a region where the force toward the exit direction is small, and the DNA is not successfully transported to the exit. There is sex.

  In contrast, in FIG. 72B, the substrate-side electrode 106 is within the range of the region 113. In this case, 0V is applied to the electrode rod immersed in the channel inlet, a positive voltage is applied to the electrode rod immersed in the channel outlet, and negative charges and DNA are received when a positive voltage is applied to the substrate-side electrode 106. The direction of the force is different from that in FIG. 72A, particularly in the portion surrounded by the dotted line. The direction of the electric field is effectively induced in the exit direction. Therefore, compared with FIG. 72A, DNA is smoothly guided toward the exit. In addition, in the fine flow path part provided with the detection part, the component of the force attracted to the substrate side certainly exists, and the effect of inducing DNA to the substrate side is well maintained. The detection electrode is preferably a region where DNA is effectively guided to the substrate side, and among the regions 113, it is preferable to be in a region on the substrate electrode.

  Further, FIG. 72C shows a structure in which the upper electrode 115 is provided on the upper part of the flow channel with the insulating film interposed therebetween in order to further enhance the effect of inducing the DNA to the substrate and increase the reliability of the detection signal. In the figure, 0V is applied to the electrode rod immersed in the channel inlet, a positive voltage is applied to the electrode rod immersed in the channel outlet, a positive voltage is applied to the substrate side electrode, and 0V is applied to the upper electrode. Figure 2 shows an example of the direction of negative charge and the force that DNA is subjected to. The direction of the electric field (the direction of the negative charge and the force received by the DNA) in the region sandwiched between the upper electrode and the substrate side electrode is uniform compared to FIGS. 72A and 72B, and the value of the component of the force that pulls the DNA toward the substrate side Is also big. Moreover, the movement control in the height direction of the DNA by the electric field applied by preparing only the upper electrode and applying a voltage thereto has the same effect as the control performed by the substrate side electrode. As an example of the structure, FIGS. 73A and 73B show a structure in which an upper electrode is added to the structure of FIGS. Thus, it is particularly useful for a structure that does not have a substrate-side electrode for controlling the DNA height independently.

  As shown in FIGS. 74A and 74B, DNA can be more smoothly migrated by arranging a plurality of substrate-side electrodes independently in the vicinity of a plurality of detection electrode pairs. By making the region where DNA is attracted to the bottom surface by the electric field of the substrate side electrode in the flow path and moving only in the vicinity of the detection electrode part, the interaction between the DNA and the bottom surface in other regions is reduced. Because. Then, fluctuations in the movement speed of the DNA in the direction of the flow path caused by interaction such as frictional force that the DNA receives from the bottom surface can be reduced, and the possibility of stopping the movement can be reduced. Therefore, the reliability of the detection signal is improved.

  In addition, it is possible to improve detection accuracy by applying different voltages to a plurality of substrate-side electrodes existing under different detection electrode pairs. That is, an optimum voltage can be applied to improve detection accuracy in accordance with variations in the flow path shape in the vicinity where each detection electrode pair exists. The optimum voltage is, for example, the movement of DNA in the flow path direction caused by interaction such as friction force that DNA receives from the bottom surface while drawing DNA to the substrate side with sufficient detection accuracy at each detection location. It is a voltage that minimizes the effects of speed fluctuations and the possibility of stopping movement.

In addition, regarding the arrangement of the upper electrode 115, the same effect can be obtained for the same reason as described above by arranging the upper electrode 115 only in the vicinity of the upper part independently of the plurality of detection electrode pairs. As an example, FIGS. 75A and 75B are diagrams in which the upper electrode is arranged only in the vicinity of the upper portion of the detection electrode portion. FIGS. 76A and 76B are diagrams in which the upper electrode is arranged only in the vicinity of the upper portion of the detection electrode portion in the structure of FIGS. 60A and 60B.
The present techniques can also be applied to the devices of the embodiments described in this specification and other types of devices.

  In the device provided with the substrate-side electrode, by applying an AC voltage to the substrate-side electrode, friction between the flow path and the DNA can be reduced and the DNA can be smoothly migrated. For example, the voltage applied to the solution near the flow path inlet is 0 V, the voltage applied to the flow path outlet is V (positive voltage), and the voltage applied to the substrate side electrode is a minute amplitude centered on V (positive voltage). By using a certain voltage, DNA can be migrated smoothly. Similarly, in a device provided with an upper electrode, the same effect can be obtained even when an AC voltage is applied to the upper electrode.

  When measuring with the device of the above example, the distance between each base of the DNA can be increased by feeding the solution in the direction opposite to the direction of DNA progression. That is, DNA is electrophoresed by an electric field formed by the voltage applied to the flow path inlet and outlet, while the solution is fed by pressure in the direction opposite to the migration direction. The distance between each base can be increased by the force resulting from the pressure of the solution. In FIG. 77, reference numeral 108 represents a DNA traveling direction (electrophoresis direction by an electric field), reference numeral 109 represents a liquid feeding direction by application of an external pressure, and reference numeral 110 represents water molecules, other molecules, ions in the solution. This indicates the force that increases the distance between each base of DNA by collision.

  Since the distance between each base of DNA becomes long, the information of the base to be detected and the information of the base next to the base become difficult to mix during signal detection, and the reliability of the detection signal is improved. By extending the DNA, the contracted arrangement as shown in FIG. 3B is not adopted, and the arrangement as shown in FIG. 4A is approached.

  Note that this method can also be applied to devices in forms other than the above embodiments.

  A device for controlling the arrangement of DNA in the flow direction in the height direction and the horizontal direction using a fringe electric field is shown. The device structure and material to be described are examples for embodying the idea of the present invention, and the material and dimensions are not strictly specified. FIG. 78A is a cross-sectional view of a device having a channel 203 in an insulating film, across the channel. The cross-sectional view is a cross-sectional view at a place where there is no detection electrode pair. There is a flow path in the SiN film 102, a fringe electrode 116 with an insulating film sandwiched at the bottom of the flow path, and a fringe electrode 117 with an insulating film sandwiched beside the 116. By making the voltage 117 (V117) lower than the voltage 116 (V116), the direction of the force received by the DNA and the negative charge becomes the electric line of force 111. Since the electric lines of force 111 are directed to the center and bottom of the channel 203, DNA is also disposed at the center and bottom of the channel 203. Therefore, the dispersion | variation in the arrangement | positioning in the flow path of DNA is suppressed, and the reliability of the signal measured by a detection electrode pair improves.

  Also, as shown in FIG. 78B, the same effect can be obtained even if the fringe electrode 117 is arranged at the upper part of the flow path. Further, as shown in FIG. 78C, it goes without saying that the same effect can be obtained even when the fringe electrodes 116 and 117 shown in FIG. 78A are reversed and arranged on the upper surface side of the flow path. Alternatively, as shown in FIG. 78D, the arrangement of the fringe electrodes 116 and 117 shown in FIG. 78B is reversed to place the fringe electrode 117 on the upper surface side of the flow path and the fringe electrode 116 on the lower surface side of the flow path. However, it goes without saying that the same effect can be obtained.

  Further, even when the fringe electrode is only on one side, the electric field between 117 and 116 is applied to determine the electric field in the height direction and the lateral direction in the flow path, so that there is an effect of fixing the DNA arrangement. However, for better control, it is preferable to provide fringe electrodes 117 on both sides.

100 ... silicon (Si) substrate,
101 ... Silicon oxide film (SiO ₂ ),
102 ... Silicon nitride film (SiN),
103 ... resist,
104 ... electrode for detection,
105 Amorphous silicon film,
106: Substrate side electrode part,
107: DNA lateral control electrode,
108 ... DNA traveling direction,
109 ... Solution feeding direction,
110: Water molecule, other molecule, force acting on each DNA base by ions,
111 ... Negative charge, direction of force due to electric field received by DNA,
112 ... Solution inlet and outlet,
113... A fine flow path section provided with a signal detection section,
114... Electrode rod for creating an electric field for migrating DNA,
115 ... Upper electrode,
116,117 ... fringe electrode,
118 ... lid,
200 ... DNA,
201 ... 1 base 202 in DNA ... pore,
203: A flow path portion.

Claims (15)

A fluid analysis device for analyzing a sample contained in a solution by current measurement,
A conductive film provided on a substrate;
A first electrode for applying a voltage to the conductive film;
A groove serving as a flow path for the solution with an upper surface extending from the first region to the second region of the first insulating film provided on the conductive film;
At least a pair of electrode terminals provided opposite to both side surfaces of the groove,
A second electrode and a third electrode for applying a voltage to the wiring connected to each of the pair of electrode terminals;
When passing the solution through the groove, a voltage is applied between the second electrode and the third electrode, and flows between the second and third electrodes through the sample contained in the solution. A fluid analysis device, wherein the sample is analyzed by measuring an electrical signal.   The wiring includes a first wiring region that terminates at one of the pair of electrode terminals, and a second wiring region that terminates at the other of the pair of electrode terminals, and an extension of the first wiring region is the groove portion. The fluid analysis device according to claim 1, wherein the second wiring region is disposed on the extension. By applying a voltage to the first electrode,
The fluid analysis device according to claim 1, wherein the passage position of the sample passing through the groove is controlled in the groove.   The fluid analysis device according to claim 1, further comprising a lid portion that is provided on the first insulating film so as to cover the groove portion and is configured by a second insulating film.   The fluid analysis device according to claim 1, wherein a difference in height between the surface of the wiring and the surface of the first insulating film is smaller than a film thickness of the wiring.   The fluid analysis device according to claim 1, wherein a film thickness of the wiring is smaller than a film thickness of the first insulating film, and the wiring is embedded in the first insulating film. A fourth electrode made of a conductive material provided on the first insulating film so as to cover the groove,
The fourth electrode is insulated from the conductive film via an insulating film,
The fluid analysis device according to claim 1, wherein the passage position of the sample passing through the groove is controlled in the groove by applying a voltage to the fourth electrode.   The fluid analysis device according to claim 7, wherein an alternating voltage is applied to at least one of the first electrode and the fourth electrode when the solution passes through the groove. Another conductive film for applying an electric field to at least a part of the groove is provided in the vicinity of the wiring on the first insulator,
By applying a voltage to the fifth electrode connected to the other conductive film,
The fluid analysis device according to claim 1, wherein a passage position of the sample passing through the groove portion in the groove portion is controlled in a direction horizontal to the substrate surface.   The fluid analysis device according to claim 2, wherein a width of the groove is approximately the same as a size of the sample to be analyzed.   It has at least one fringe electrode that is provided below the bottom of the groove and applies a fringe electric field to the groove, or has at least one fringe electrode that is provided above the groove and applies a fringe electric field to the groove. The fluid analysis device according to claim 1. A fluid analysis device for analyzing a sample contained in a solution by current measurement,
A substrate,
A groove serving as a flow path for the solution provided on the substrate;
A conductive film provided on the upper surface of the groove portion in a direction intersecting the groove portion;
A first electrode for applying a voltage to the conductive film,
The groove part is composed of an insulator on both side surfaces, a bottom surface of the substrate, and a top surface of the conductive film.
When passing the solution through the groove, an electric signal is applied between the first electrode and the substrate through a sample contained in the solution by applying a voltage between the first electrode and the substrate. A fluid analysis device, wherein the sample is analyzed by measuring.   The fluid analysis device according to claim 12, wherein the surface of the substrate is a conductive region in the vicinity of a lower region of the groove, and an insulating region other than the vicinity of the lower region of the groove. A fluid analysis device manufacturing method comprising: a flow path for flowing a sample contained in a solution; and a wiring portion for applying an electric field to the sample passing through the flow path.
Depositing a first conductive film on the substrate to form a substrate electrode;
Forming a first insulating film on the substrate electrode, and forming a first opening having a predetermined width in the first insulating film;
Depositing a second conductive film in the first opening and the first insulating film, filling the second conductive film in the first opening using a planarization technique, and forming the wiring portion;
A second opening having a predetermined width in a direction intersecting the longitudinal direction of the wiring part is opened in the first insulating film to form the flow path, and the side surface of the flow path intersecting the wiring part is formed on the side surface of the flow path. And a step of forming a terminal portion of the wiring. The step of forming the second opening includes
Opening a second insulating film deposited on the second conductive film and providing an opening;
A third insulating film is deposited on the second insulating film including the opening, and the third insulating film is etched back to reach the upper surface of the second insulating film;
The width of the opening is narrowed by the third insulating film remaining as a sidewall on the side surface of the opening, and the first insulating film is processed using the third insulating film remaining as the sidewall as an etching mask. The method of manufacturing a fluid analysis device according to claim 14.

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