KR100907787B1 - A method for focusing patterning of charged particles using a patterned perforated mask and a mask used therein - Google Patents

Abstract

The present invention relates to a method for focusing patterning of charged particles using a pattern-perforated mask and a mask used therein, wherein a pattern-perforated mask having an electrode layer or an ion layer on one or both surfaces thereof is placed on a substrate to be patterned, and a voltage is applied. It is characterized in that the focusing patterning is induced by forming an electrodynamic focusing lens by applying, and according to the method of the present invention, the desired structure can be precisely and efficiently generated without generating a noise pattern. Focusing patterning can be repeated.

Description

METHODS FOR FOCUSING PATTERNING CHARGED PARTICLES USING A MASK WITH PATTERNED HOLES AND THE ELECTRODYNAMIC FOCUSING MASK USED THEREIN}

The present invention relates to a method and a mask used for repetitively focusing patterning a structure with high precision and high efficiency without generating a noise pattern by using a pattern-perforated mask.

Patterning techniques for selectively controlling charged particles to produce micro- or nano-sized structures at desired locations play an important role in the development of materials with new physical and chemical properties. In particular, in the case of manufacturing a nanostructure by increasing the focusing effect, it is expected that it will be useful for the production of optical, electrical, magnetic devices in the future.

For patterning of such charged particles, a dielectric film is first formed on a conductor or non-conductor support, and may be an electron beam or ion beam focusing device (SEM or FIB), an atomic force microscope (AFM), or micro-contact printing. The charge was transferred onto the dielectric film to effect particle patterning, ie position control and adhesion.

According to the research results published after 2003, after forming a photo-resistor on a support and patterning the formed photoresist, the charged particles are injected while controlling the charge on the surface of the photoresist using electric field formation and ion charge injection. By this, a method of electrically focused deposition of charged particles at a desired pattern position has been introduced.

However, in the case of forming the photoresist film on the support as described above, there was an inconvenience in that the photoresist film cannot be reused and the photoresist patterning must be performed every time to form a three-dimensional lamination system. In addition, there is a limit to the level of charge control of the attached surface ions, which makes it unsuitable for future nanometer or atomic level patterning techniques.

On the other hand, during vacuum deposition, a metal mask having a perforated pattern may be used. In this case, it is difficult to manufacture a nano-sized pattern and a large aspect ratio has a problem in that a material loss due to mask contamination is very large. In addition, in the case of electron beam photolithography (EPL), it is possible to produce a nano-sized pattern, but a problem arises in that the material is attached (contaminated) to the mask surface and the size of the pattern is irregularly reduced.

It is therefore an object of the present invention to provide a method and a mask for use in which the desired structure can be repeatedly focused and patterned with high precision and efficiency without generating a noise pattern.

In order to achieve the above object, the present invention

(1) placing, in a grounded reactor, a pattern-perforated mask having an electrode layer or an ion layer on one or both surfaces on a substrate to be patterned, and applying a voltage to form an electrodynamic focusing lens; And

(2) introducing charged particles to guide the charged particles to the substrate through the pattern of the mask and to focus attach to the substrate;

It includes, provides a patterning method of focusing the charged particles (patterning).

The present invention also provides a patterned perforated mask having an electrode layer or an ion layer on one or both sides of a plate or film insulator, which is used in the method.

According to the patterning method of the present invention, it is possible to focus and pattern a desired structure with high precision and high efficiency in a gaseous state without generating a noise pattern, and the pattern of the same size due to the adjustment of the focusing effect by controlling the amount of charge and voltage Particle patterns of various sizes can be fabricated using masks, and large-area patterns can be produced, which is expected to be useful for nanoparticle-based device fabrication in the future. In addition, the mask can be used repeatedly, and the particle loss that can occur in the existing independent high aspect ratio mask structure can be minimized to provide an economical advantage.

In the charged particle patterning method according to the present invention, in patterning charged particles by forming an electric field inside the reactor, a pattern-perforated mask having an electrode layer or an ion layer on one or both surfaces thereof is placed on a substrate to be patterned, and the voltage is reduced. It is characterized by inducing focusing patterning by applying an electric focusing lens to form. According to the method of the present invention, by controlling the charge and the voltage directly, it is possible to change the collecting speed of the charged particles, thereby enabling patterning in a wide range of sizes from micro size to nano size.

In step (1) of the method of the present invention, in a grounded reactor, a pattern-perforated mask having an electrode layer or an ion layer on one or both surfaces is placed on a substrate to be patterned, and an electric voltage is applied to form an electrically focused lens. .

The pattern-perforated mask used in the present invention forms a perforated pattern for a plate-like or film-like insulator and then forms an electrode layer or an ion layer on one or both sides thereof (in this case, the electrode layer may be a non-conductor plate if necessary). It may be formed on the side of the film, or the wall surface of the perforated pattern), or by forming an electrode layer or an ion layer on one or both sides of the plate-like or film-like insulator, and then forming a perforated pattern. Preferably, the pattern-perforated mask of the present invention may have an electrode layer on both sides or an ion layer on one side.

The plate or film insulator may be made of a material selected from ceramics, insulating polymers, and insulating natural materials containing both oxides and nitrides, and the perforated pattern may be formed by, for example, electron beam photolithography. have.

An electrode layer may be formed by coating a conductive material on one or both surfaces of the insulator plate or film according to a conventional method, and the thickness of the electrode layer is preferably 20 to 200 nm. Any conductive material may be used as the conductive material, and for example, a metal, a conductive polymer, a conductive ceramic, a conductive natural product, or a mixture thereof may be used.

In addition, an ion layer may be formed on the surface by injecting gas ions charged at the same polarity (+, −) as the charged particles to be injected later to the surface of the non-conductive plate or film, wherein the ion layer coating amount is determined by the thickness of the mask, and It is appropriately determined in consideration of the voltage applied to the mask and the chamber. The charged gas ions may be prepared by applying a voltage, for example, in the range of 5 to 6 kV, to the gas using an ion supply device such as corona discharge, and as a representative example, nitrogen ions (N ₂ ⁺ , N ₂ ⁻ ). , helium ions (He ^+, He ^-) and argon on the (Ar ^+, Ar ^-) and the like, but is not limited to these.

In applying a pattern-perforated mask on a substrate and applying a voltage, for example, a mask having electrode layers on both sides is placed on a substrate (insulator), and a voltage is applied to each of both electrode layers, or a mask having an ion layer on one surface thereof. Is placed on the substrate (conductor or semiconductor) so that the opposite side of the ion layer is in contact with the substrate, and a voltage is applied to the substrate, and an electric focus is formed while an electric field is formed in the reactor, that is, around the substrate and the mask. At this time, the value of the voltage to be applied can be appropriately selected according to the size of the mask and the size and density of the charged particles.

Furthermore, in the present invention, a multilayer mask obtained by laminating a plurality of masks having an electrode layer, a mask having an ion layer, or a random combination thereof can be used, wherein the multilayer mask forms a multi-electric focusing lens on the same principle as described above. When manufacturing a multilayer mask including the ion layer only on the outermost surface, lamination may be performed first and then the ion layer may be formed on the outermost surface, or the lamination may be performed so that the ion layer of the mask having the ion layer is exposed. On the other hand, when manufacturing a multilayer mask including the ion layer in the middle, it is preferable to form the ion layer by inserting the charged gas ions into the above-prepared space after lamination, leaving a space where the ion layer is to be located.

For example, a five-layer mask having an electrode layer or an ion layer can form a dual electric focusing lens.

In step (2) of the method of the present invention, charged particles are introduced into the reactor to guide the charged particles to the substrate and focus attach to the substrate through the pattern of the mask. When the charged particles are injected toward the substrate to be patterned, the charged particles are directed to the substrate through the perforated pattern of the mask by the action of the electric field formed inside the reactor, which is much smaller than the perforated pattern due to the electrical focusing lens, A focused pattern structure is formed on the substrate. At this time, by controlling the charge and the voltage directly through the control of electronic devices such as voltage and current supply device, a battery capable of charging and discharging (capacitor), it is possible to adjust the size of the focusing pattern by changing the focusing speed of the charged particles.

The introduction of charged particles can be carried out in various ways by conventional methods, for example, pre-charged particles may be injected together with a carrier gas, or they may be injected while charging particles by electrospray.

Charged particles used in the present invention may be prepared according to a conventional method, for example, by converting a specific material (eg, Ag) into polydisperse particles by using an evaporation and condensation method. The particles are made bipolar charge with a radioactive material (eg 210-polonium) into the Boltzmann distribution, and then passed through a differential mobility analyzer (DMA) to obtain a monopolar charged spherical particle. Can be extracted.

In accordance with one embodiment of the present invention, the principle of forming a focused pattern structure on a substrate by applying a voltage to each of the electrode layers formed on both sides of the pattern-perforated mask is shown in FIG. 1. In FIG. 1, the charged particles 1 pass through the insulator plate or the film 2 and are focused by an electrical lens to form the pattern structure 4 on the substrate 3. Both sides of the non-conductive plate or film 2 are coated with electrode layers 5 and 6, and the electrode layers 5 and 6 are connected to voltage applying means 8 and 7, respectively, to apply a voltage to control the focusing effect. Through this, the size of the particle pattern can be adjusted.

The results of simulating the principle described in FIG. 1 are shown in FIG. 2. As can be seen in FIG. 2, the equipotential lines 9 and the electric force lines 10 are formed by grounding the main body of the reactor (metal chamber) 30 and applying a voltage to the two electrode layers 5, 6. The charged particles 1 move along the electric force line 10 by the electric force to move to the substrate 3.

In accordance with one embodiment of the present invention, the principle of forming a focused pattern structure on a substrate using an ion layer formed on one surface of a pattern-perforated mask and applying a voltage to the substrate is shown in FIG. 3. In FIG. 3, after the ion is implanted into the upper portion of the non-conductive plate or film 2 to form the ion layer 11, the charged particles 1 may be electrically controlled by applying a voltage to the substrate 3.

The results of simulating the principle described in FIG. 3 are shown in FIG. 4. As can be seen in FIG. 4, the isoelectric hypothesis is grounded by grounding the body of the reactor (metal chamber) 30, using an ion layer 11 attached to a non-conductive plate or film 2, and applying a voltage to the substrate 3. (9) and electric field lines 10 are formed. The charged particles 1 move along the electric force line 10 by the electric force to move to the substrate 3.

An example of the multilayer mask in which the mask in which the electrode layer was formed and the mask in which the ion layer was formed are laminated is shown in FIG. The multilayer mask 20 shown in FIG. 5 includes three electrode layers 13, 14, 16 and two ion layers 12, 15.

The simulation results of the principle of forming two electrically focused lenses when the multilayer mask of FIG. 5 is applied are shown in FIG. 6. As can be seen in FIG. 6, the main body of the reactor (metal chamber) 30 is grounded, two ion layers 12 and 15 are used, and two electrode layers 13, 14 and 16 are applied by voltage. Lenses 21 and 22 are formed. From this, it can be seen that the particles are condensed multiplely by the equipotential lines 23 and the electric field direction 24 formed thereby, so that a smaller focusing pattern can be produced.

In the method of the present invention, if the perforated pattern is formed in the size of several hundred nanometers, it is expected that the pattern structure on a molecular basis can be formed by the electric focusing effect and the inertial effect of the particles by the electric field. In particular, a photograph of a pattern-perforated multi-layer mask in the form of a film is shown in FIG. 7, which can be used for more precise control.

In addition, a patterning process according to one embodiment of the invention is shown in FIG. 8.

After the process of forming the pattern structure by attaching the charged particles to the substrate is completed, the used plate or film mask can be separated from the substrate and used permanently for subsequent patterning. Conventionally, particles are stuck to the surface of the mask to be used, resulting in particle loss and contaminating the mask. However, in the present invention, particles do not adhere to the mask surface at all, and particles are focused on only the desired position, so there is no fear of mask contamination and particle loss. .

Example

Example 1

First, a silicon nitride film having a thickness of 1 μm is deposited on a silicon wafer, and then a nitride mask having a 4 μm perforated line pattern as shown in FIG. 9 (a) is fabricated through a conventional photolithography process on the deposited silicon nitride film. It was.

The ions were then prepared in a conventional manner by passing nitrogen through a corona discharger (voltage 5 kV), converting Ag into polydisperse particles using evaporation and condensation methods and then converting the particles into radioactive material. (210-polonium) was used to make bipolar charge particles in the Boltzmann distribution. The charged particles were then passed through a differential mobility analyzer (DMA) to selectively extract charged spherical particles having a diameter of 20 nm.

Charged particles were focused and patterned on the principle shown in FIG. 2 using the apparatus shown in FIG. 1. That is, the silicon nitride mask was placed on the silicon substrate in the reactor (metal chamber) 30, and a voltage of -4 kV was applied. Ions and charged particles prepared while the main body of the reactor 30 was grounded were injected. At this time, the ions are attached to the mask surface to form the equipotential lines 9 and the electric force lines 10, whereby the charged particles 1 are moved along the electric force lines 10 by the electric force to attach to the substrate 3 It became. As a result, the adhered particles formed a pattern with a line of about 300 nm smaller than the perforated mask pattern, as shown in Fig. 9B.

Example 2

After spin-coating a photoreceptor (LOR-30B, Microchem Co.) on a silicon substrate, it was baked at 95 ° C. for 6 minutes. Epoxy material (SU8-2050, Microchem Co., Ltd.) was spin coated (500 rpm, 5 seconds) on the photoconductor, and then the pattern was exposed, and then immersed in the developing material of SU-8 (Microchem Co.) for 30 minutes. The same pattern-perforated mask was obtained. An aluminum electrode having a thickness of 20 nm was deposited on the mask to prepare an electrode mask having a 20 μm perforated line pattern as shown in FIG. 10 (a).

A mask on which an aluminum electrode was deposited was placed on a silicon substrate in the reactor (metal chamber) 30, and a voltage of −1 kV was applied. Ion and charged particles (20 nm Ag particles) obtained in the same manner as in Example 1 were injected while the main body of the reactor 30 was grounded, and the mask was punched by applying -500 V to the mask surface on which the aluminum electrode was deposited. An electric focusing lens was formed on top. Accordingly, the charged particles 1 were attached to the substrate 3 by moving along the electric force line 10 by the electric force. As a result, the attached particles formed a focused pattern about 3 μm in size, which is much smaller than the perforated mask pattern, as shown in FIG. 10 (b).

1 is a schematic diagram showing the principle of forming a focused pattern structure on a substrate by applying a voltage to each of the electrode layers formed on both sides of the pattern-perforated mask, according to one embodiment of the invention,

2 is a schematic diagram of the principle of Figure 1 implemented through a simulation,

3 is a schematic diagram showing a principle of forming a focused pattern structure on a substrate using an ion layer formed on one surface of a pattern-perforated mask and applying a voltage to the substrate, according to one embodiment of the present invention;

4 is a schematic diagram of the principle of Figure 3 implemented through the simulation,

5 is a structural schematic diagram of an example of the multilayer mask of the present invention in which a mask having an electrode layer and a mask having an ion layer are stacked in a plurality;

FIG. 6 is a schematic diagram illustrating a principle of forming two electric focusing lenses by applying the multilayer mask of FIG. 5 through simulation;

7 is a photograph of a pattern-perforated multilayer mask in the form of a film used in the method of the present invention,

8 is a schematic view of a patterning process according to one embodiment of the invention,

9 (a) and 9 (b) are scanning microscope (SEM) photographs (b) of the silicon nitride mask (a) and the line patterned structure fabricated in Example 1, respectively,

10 (a) and 10 (b) are optical photographs (b) of the electrode mask (a) and the structure patterned in a line shape, respectively, prepared in Example 2. FIG.

<Short description of drawing symbols>

1: charged particle 2: insulator plate or film

3: substrate 4: pattern structure

5, 6: electrode layer 7, 8: voltage application means

9, 23: equipotential lines 10: electric field lines

11: ion layer 12, 15: ion layer formed on the mask

13, 14, 16: electrode layers 21, 22 formed on the mask: lenses

23: equipotential lines

24: electric field direction formed by equipotential lines

30: reactor (metal chamber) 31: charged particle inlet (suction)

32: exhaust vent

Claims (11)

(1) placing, in a grounded reactor, a pattern-perforated mask having an electrode layer or an ion layer on one or both surfaces on a substrate to be patterned, and applying a voltage to form an electrodynamic focusing lens; And (2) introducing charged particles to guide the charged particles to the substrate through the pattern of the mask and to focus attach to the substrate; Containing, the patterning method of focusing the charged particles (patterning). The method of claim 1, Method for patterning charged particles, characterized in that the electrode layer of the pattern-perforated mask of step (1) has a thickness of 20 to 200 nm. The method of claim 1, Method for patterning charged particles, characterized in that the electrode layer of the pattern-perforated mask of step (1) is further present on the wall surface of the perforated pattern. The method of claim 1, A method of patterning the charged particles, characterized in that the ion layer of the pattern-perforated mask of step (1) is formed by injecting gas ions charged at the same polarity as the charged particles against the surface of the mask. The method of claim 4, wherein A method for patterning charged particles, wherein the gas ions are nitrogen ions, helium ions, or argon ions prepared by applying a voltage to the gas. The method of claim 1, In step (1), a mask having electrode layers on both sides is placed on a substrate, and a voltage is applied to each of the both electrode layers. The method of claim 1, In step (1), a mask having an ion layer on one side is placed on the substrate so that the opposite side of the ion layer is in contact with the substrate, and a voltage is applied to the substrate. The method of claim 1, The patterned perforated mask of step (1) is a multilayer patterned method of charging particles, wherein a plurality of masks having an electrode layer, a mask having an ion layer, or a combination thereof are laminated. The method of claim 1, In step (2), the patterning method of focusing the charged particles, characterized in that the size of the pattern is adjusted by varying the focusing speed of the charged particles by controlling the charge and the voltage using a voltage and current supply device, a battery or a battery. A pattern-perforated mask having an electrode layer or an ion layer on one or both sides of a plate or film insulator, used in the method of any one of claims 1 to 9. The method of claim 10, A pattern-perforated mask, characterized in that the mask is a multilayer of a plurality of stacked masks having an electrode layer, a mask having an ion layer, or a combination thereof.

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