JP2005349496A - Method of depositing micro-substance on substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of depositing a micro-substance of nano-scale in an arbitrary position of a substrate. <P>SOLUTION: According to a method of depositing micro-substance on the substrate, a micropipette in which an electrode is inserted into the interior, and which is filled with a dispersion liquid containing charged microsubstance obtained by dispersing microsubstance in an aqueous liquid, is disposed with the tip close to the substrate surface, and subsequently an electric field is applied between the electrode and the substrate, thereby electrically migrating the charged microsubstance in the dispersion liquid toward the substrate surface and then discharging the same from the tip of the micropipette to be deposited on the substrate surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for depositing nanoscale micromaterials on a substrate.

  Along with the development of nanotechnology in recent years, advanced technologies in micro domains such as electronic devices, memories, and nanomachines are attracting attention. Conventionally, photolithography, which has a proven track record in semiconductor device processes, has been used to manufacture such fine devices, but photolithography requires a series of processes such as exposure, development, and etching, so the entire system is complicated. In addition, there is a problem that the processing size is limited by the wavelength of light.

  Non-Patent Document 1 introduces various micromachining techniques such as nanoscale ultrasonic vibration cutting using a scanning probe microscope and pipette probe micromachining.

  A scanning probe microscope moves along the surface of an object to be processed such as a substrate while monitoring the position of the tip of a needle-like tool named a probe with an imaging device using a laser and a photo detector (sensor). An optical apparatus that observes the state of the substrate at a predetermined position, and Non-Patent Document 1 describes that microfabrication is possible by using this apparatus.

In Non-Patent Document 1, as one of microfabrication, a micropipette with an electrode wire inserted therein is used as a probe, and an ion solution such as an aqueous copper sulfate solution is spotted on the surface of the substrate to perform metal plating (dot plating). How to do is described.
Applied Physics, Vol. 73, No. 4 (2004), pages 490-493

  It is an object of the present invention to provide a method for depositing various kinds of nanoscale micro substances such as carbon nanotubes, protein particles, DNA particles, metal or non-metal fine particles at arbitrary positions on a substrate.

  The present invention provides a micropipette in which an electrode is inserted and filled with a dispersion containing a charged fine substance obtained by dispersing a fine substance in an aqueous liquid, and the tip of the micropipette is close to the substrate surface. Next, by applying an electric field between the electrode and the substrate, the charged fine substance in the dispersion is electrophoresed toward the substrate surface and then discharged from the tip of the micropipette. There is a method of depositing a minute substance on a substrate comprising depositing on a substrate surface. The dispersion in the present invention means a dispersion using an aqueous medium or oily medium (such as an organic solvent) as a dispersion medium.

  By using the method of the present invention, it becomes possible to deposit various kinds of nano-scale minute substances such as carbon nanotubes, protein particles, DNA particles, metal or non-metal fine particles at arbitrary positions on the substrate. .

  A method for depositing a minute substance on a substrate of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram for explaining a basic configuration of a scanning micropipette probe microscope apparatus that can be advantageously used for carrying out the method of depositing a micro substance on a substrate of the present invention. Pipette probe microscope devices are already known.

  In FIG. 1, a scanning micropipette probe microscope apparatus includes a precision base 2 on which a substrate (or sample) 1 is placed, and a precision base PZT (which causes precision movement in the vertical and horizontal directions and in the height direction (ie, XYZ directions)). Lead zirconate titanate porcelain) Micro-pipette (probe) 4 that can move relatively in any direction above element 3 and substrate 1, and a shear force applied to the tip of the micro-pipette to apply fine lateral vibration A PZT (lead zirconate titanate porcelain) vibrator 5 to be excited, an oscillator 6 for driving the excitation of the PZT vibrator, a laser diode 7 for irradiating the tip of the micropipette with laser light, and a laser pipe for irradiating the tip of the micropipette Lens 8 for further focusing the laser light to be transmitted, laser transmitted through the tip of the micropipette or diffracted at the tip A two-divided photodetector 9 that collects light and converts it into a current signal, a current-voltage converter 10 that converts a current signal output from the photodetector into a voltage signal, a voltage signal converted by the current-voltage converter, and a micropipette Arithmetic circuit 11 for calculating the position information of the tip of the head, a lock-in amplifier 13 for coupling the arithmetic circuit and the precision base control circuit 12 (oscillation information from the oscillator 6 is input), and PZT for moving the precision base A PZT driver 14 for driving the element 3, a computer 15 for sending precise movement information to the PZT driver based on control information from the precision base control circuit, and information on the state of the tip of the micropipette output from the computer It is comprised from the display 16 displayed as information.

  FIG. 2 is a diagram illustrating the configuration of a micropipette with electrodes that can be advantageously used to carry out the method of depositing a micromaterial on the substrate of the present invention, and the principle of the micromaterial deposition. An electrode (for example, a wire electrode) 17 connected to an external power source is provided inside the micropipette 4. The electrode 17 and the base 2 are electrically connected via a power source, and a voltage is applied between the electrode 17 and the base 2 when necessary.

  FIG. 2 shows a state in which the tip of the micropipette 4 is arranged close to the surface of the substrate 1 by operating the scanning micropipette probe microscope apparatus of FIG.

  Since the method of depositing a minute substance on the substrate of the present invention can be advantageously performed by using the apparatus shown in FIGS. 1 and 2, the present invention will be described with reference to FIGS. The method will be described in detail.

  The scanning micropipette probe microscope apparatus itself is already on the market, and can be prepared by purchasing a commercially available product or making it yourself. However, since the micropipette used in the present invention is a very thin glass tube having an inner diameter of the opening at the tip of 1 μm or less, particularly about 200 nm or less, it is usually a thin glass tube called a capillary glass tube ( For example, an outer diameter of 1.0 mm and an inner diameter of 0.6 mm are manufactured by performing a heat pulling operation using a heating device called a micro puppet puller.

  Next, an electrode such as the wire electrode 17 is attached to the micropipette as shown in FIG. 2, and the sample solution is put into the micropipette with an electrode thus manufactured. The sample liquid is a dispersion liquid in which various kinds of nano-scale minute substances such as carbon nanotubes, protein particles, DNA particles, metal or non-metal fine particles are dispersed in an aqueous medium such as pure water. In general, a fine substance typified by metal nanoparticles is charged positively or negatively when dispersed in an aqueous medium to form a colloidal solution. Therefore, the minute substance in the sample solution does not necessarily need to be subjected to a treatment for charging in many cases, but may be subjected to a known charging treatment if necessary.

  Next, the electrode-equipped micropipette 4 filled with the sample solution is attached to the excitation PZT vibrator 5 shown in FIG. In the apparatus of FIG. 1, vibration is generated in the excitation PZT vibrator 5 according to the signal from the oscillator 6, and this vibration is transmitted to the tip of the micropipette 4, and the tip of the micropipette is slightly in the lateral direction. It vibrates (for example, at a vibration amplitude of 2 to 3 nm). A laser beam emitted from a laser diode 7 and irradiated with a laser beam further focused by a lens 8 is irradiated onto the tip portion under the vibration of the micropipette and transmitted through the tip portion or diffracted by the tip portion. Light is received by the diode 9 and converted into an electrical signal. This signal is subjected to necessary electrical processing through the current / voltage circuit 10, the arithmetic circuit 11, the lock-in amplifier 13, and the control circuit 12, and is input to the computer 15. Is done. Then, the state of the tip of the myro pipette is imaged in real time on the display 16. While confirming the image of the micropipette tip, the PZT driver 14 drives the precision moving PZT element 3 to precisely move the precision base 2 in the vertical and horizontal directions and in the height direction (that is, the XYZ directions) The tip of the micropipette 4 is brought close to a desired position on the surface of the substrate 1. The tip of the micropipette 4 that slightly vibrates in the lateral direction due to the vibration energy applied from the PZT vibrator 5 is subjected to a shear force as it approaches the substrate 1. become weak. When the tip of the micropipette comes into contact with the surface of the substrate 1 or is almost in contact, the vibration of the tip of the micropipette disappears.

  A voltage is applied between the precision base 2 and the wire electrode 17 while the tip of the micropipette 4 is in contact with or substantially in contact with the substrate 1 (as shown in FIG. 2) (the pole is a minute substance in the sample solution) The charged fine particles in the sample solution move toward the surface of the substrate 1 by electrophoresis, and then are discharged from the tip of the micropipette and deposited on the surface of the substrate 1. become. By such an operation, a desired amount of charged fine particles can be brought to a desired position. The state of the fine particles deposited on the surface of the substrate 1 can be observed by the display 16. Next, the movement information of the precision base 2 is transmitted from the computer 15 to the PZT driver 14, and the precision base 2 is moved again in the vertical and horizontal directions and in the height direction (XYZ) direction. The tip of the micropipette 4 is brought close to a desired position, and the same operation as described above is performed.

  Therefore, by repeating the above operation, it is possible to deposit a desired amount of minute substance at a desired position on the surface of the substrate.

It is a figure explaining the basic composition of the scanning micropipette probe microscope apparatus which can be used advantageously in order to carry out the method of depositing a minute substance on the substrate of the present invention. It is a figure explaining the structure of the micropipette with an electrode which can be advantageously utilized in order to implement the method to deposit a micromaterial on the board | substrate of this invention, and the principle of deposition of a micromaterial.

Explanation of symbols

1 Substrate 2 Precision base 3 PZT element 4 Micropipette (probe)
5 PZT vibrator 6 for excitation 6 Oscillator 7 Laser diode 8 Focusing lens 9 Two-divided photodetector 10 Current-voltage converter 11 Arithmetic circuit 12 Control circuit 13 Lock-in amplifier 14 PZT driver 15 Computer 16 Display 17 Wire electrode

Claims (5)

  An electrode is inserted inside, and a micropipette filled with a dispersion containing a charged fine substance obtained by dispersing a fine substance in an aqueous liquid is placed so that its tip is close to the substrate surface. Then, by applying an electric field between the electrode and the substrate, the charged fine substance in the dispersion is electrophoresed toward the substrate surface, and then discharged from the tip of the micropipette and deposited on the substrate surface. Depositing a micromaterial on a substrate comprising:   The method according to claim 1, wherein the distance between the tip of the micropipette and the substrate is shear force controlled by a vibrator attached to the micropipette.   Make at least one of the micropipette and the substrate movable, and move the micropipette from the tip of the micropipette to the substrate surface while changing the relative position of the substrate and micropipette arbitrarily by moving the micropipette and the substrate. The method according to claim 1, wherein a minute substance is deposited at a predetermined position.   A micropipette provided with an electrode inside for carrying out the method according to claim 1. A micropipette provided with a vibrator outside and an electrode inside for carrying out the method according to claim 2.

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