KR101537216B1 - A making process of silicon powder Using Plasma Arc Discharge - Google Patents

Abstract

A method for manufacturing silicon nanopowder according to an embodiment of the present invention comprises: a step of supplying a base material for silicon powder; a step of inserting the base material for silicon powder into a transport-type plasma device; a step of generating a thermal plasma jet by direct-current discharge inside the transport-type plasma device; a step of melting and gasifying the base material for silicon powder using the thermal plasma jet; and a step of cooling the gasified silicon to form silicon nanopowder. The silicon nanopowder can be easily manufactured by using a plasma arc discharge technique which evaporates the base material for silicon powder with a plasma arc.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a silicon powder using a plasma arc discharge method,

The present invention relates to a method of manufacturing a silicon powder using a plasma arc discharge method, and more particularly, to a method of manufacturing a silicon powder using a plasma arc discharge method capable of producing nano-sized silicon powder by a simple method .

Silicon powders are currently being developed and used in a wide range of applications, including lithium ion batteries, printed electronics and solar applications.

On the other hand, a nano powder is a fine particle having a size of 100 nm or less and has a high surface area per unit volume, so it exhibits properties such as catalytic ability, foreign matter adsorption ability, strong cohesive force, and capillary condensation .

The nano powder manufacturing process includes a solid phase method, a liquid phase method, a vapor phase synthesis method and the like depending on the starting phase. At present, in the nano powder manufacturing process, liquid phase method, which is a chemical method using precipitation in the liquid phase, that is, precipitation by ion association in a solution, is used the most, but filtration and drying processes are very complicated and maintenance of high purity is difficult .

Based on these problems, the meteorological process is becoming the most ideal and optimal process for the nano powder manufacturing process. This is because the particle size distribution can be easily controlled according to the production conditions, the process is very simple, and nanomaterials having chemical homogeneity can be manufactured with a small number of intervening chemicals.

Plasma combustion (US Patent No. 5486675) and fuel gas combustion (US Patent No. 5788738) have been reported as technologies that have been proven to be commercialized among the vapor-phase processes.

However, the above-mentioned techniques are limited to a suspension in which a precursor supplied to obtain a nanoparticle powder of metal is in the form of a liquid phase containing the metal element, i.e., a salt, a hydroxide, a nitride or a solution thereof in a solvent Should be supplied.

Therefore, there is a problem that particles after synthesis are easily oxidized because the recovery rate of the particles is small and the process is performed in air.

In order to solve the above problems, Korean Patent No. 726592 discloses a plasma combustion method in which synthesis is carried out in vacuum while the initial raw material supplied to the synthesis reaction chamber is in a solid form, (Cu) or copper (Cu) alloy composition by controlling the flow rate and pressure of the generated gas by using an RF plasma firing apparatus, which is a new process in which nano-sized metal particles are obtained without being oxidized Lt; / RTI >

However, the RF plasma tends to become unstable unless the power source is fairly expensive and does not well match the condition variations on the plasma side.

Further, there is a problem of high energy loss and low efficiency, and there is a problem that the manufacturing cost is increased because a transfer gas is necessarily required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing an economical and highly efficient nano-sized silicon powder.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to solve the above-mentioned problems, the present invention provides a method of manufacturing a semiconductor device, comprising: providing a silicon powder base material; Generating a thermal plasma jet by DC discharge; Melting and vaporizing the silicon powder base material using the thermal plasma jet; And cooling the silicon in the vaporized state to produce silicon nano powder.

The present invention also provides a method for producing a silicon nano powder, wherein the silicon powder base material is a silicon powder base material in a bulk state or a silicon powder base material in a powder state.

The method may further include the step of charging the silicon powder preform into the transfer type plasma device after the step of providing the silicon powder preform, wherein the step of generating the thermal plasma jet by the DC discharge comprises: Wherein the silicon nanocrystals are formed through a plasma apparatus.

The present invention also provides a method of manufacturing a semiconductor device, comprising: providing a semiconducting powder preform; Generating a thermal plasma jet by DC discharge; Melting and vaporizing the semiconductor powder base material using the thermal plasma jet; And cooling the semiconducting material in the vaporized state to produce a semiconducting nano powder.

The method may further include the step of charging the semiconductive powder preform into the transfer type plasma device after the step of providing the semiconductive powder preform, wherein the step of generating the thermal plasma jet by the DC discharge comprises the steps of: Wherein the silicon nanocrystals are formed through a transfer type plasma device.

According to the present invention as described above, the silicon nano powder can be easily prepared by an arc plasma discharge method in which a silicon powder base material is evaporated to a plasma arc.

1 is a schematic flow chart showing a method for producing a silicon powder according to the present invention.
2 is a schematic view showing a transfer type plasma apparatus for producing a silicon powder according to the present invention.
FIG. 3A is an XRD peak of a silicon powder from a silicon ingot, and FIGS. 3B and 3C are FE-SEM photographs of silicon powder from a silicon ingot.
FIG. 4A is an XRD peak of the silicon nano powder prepared in Experimental Example 1, and FIGS. 4B and 4C are FE-SEM photographs of the silicon nano powder prepared in Experimental Example 1. FIG.
FIG. 5A is an XRD peak of the silicon nano powder prepared in Experimental Example 2, and FIGS. 5B and 5C are FE-SEM photographs of the silicon nano powder prepared in Experimental Example 2. FIG.
6 is a view showing a crucible for fixing the anode rod and the silicon powder base material used in the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. &Quot; and / or "include each and every combination of one or more of the mentioned items. ≪ RTI ID = 0.0 >

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" And can be used to easily describe a correlation between an element and other elements. Spatially relative terms should be understood in terms of the directions shown in the drawings, including the different directions of components at the time of use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element . Thus, the exemplary term "below" can include both downward and upward directions. The components can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic flow chart showing a method of manufacturing a silicon powder according to the present invention, and FIG. 2 is a schematic view showing a transfer type plasma apparatus for producing a silicon powder according to the present invention.

Referring first to FIG. 1, a method of manufacturing a silicon powder according to the present invention includes providing a silicon powder base material (S110).

The silicon powder base material may be a bulk silicon powder base material or a powdered silicon powder base material. In the present invention, however, it is a bulk silicon powder base material in which a base material in a powder state is collected rather than a powder base material desirable.

Next, a method of manufacturing a silicon powder according to the present invention includes the step of charging the silicon powder base material into a transfer type plasma device (S120).

Generally, a plasma apparatus refers to an apparatus for plasma-generating an internal gas by performing arc discharge between both electrodes by using direct current or alternating current.

 In this case, the plasma may be a thermal plasma, and the thermal plasma generating means may be a structure using, for example, DC arc discharge between a base material placed on a hearth made of a tungsten anode rod of a general shape, A hollow cathode made of carbon or copper may be used instead of the tungsten anode rod.

6 is a view showing a crucible for fixing the anode rod and the silicon powder base material used in the present invention.

Referring to FIG. 6, a plasma can be generated by a simple method through a crucible such as a copper rod and a rod of a negative electrode such as a tungsten material.

Torches of output power of MW class have been developed by using such a hollow cathode, and the arc point on the electrode is rotated by applying a magnetic field to prevent the loss of the electrode, and the plasma is also rotated incidentally .

The most significant feature of the thermal plasma is that the maximum temperature reaches tens of thousands of K and the heat capacity is large, so that most objects can be rapidly heated and melted / evaporated.

It can be distinguished as a non-transferred type according to the structure of the torch and a transferred type in which the object is an anode and the arc is concentrated directly on the cathode of the torch.

At this time, in the present invention, it is preferable that the plasma apparatus is a transfer type plasma apparatus using direct current.

As described above, there has been disclosed a method of manufacturing a nano powder of a copper (Cu) or copper (Cu) alloy composition by controlling the flow rate and pressure of a generated gas by using an RF plasma firing apparatus.

However, the RF plasma tends to become unstable if the power source is considerably expensive and does not match the conditional fluctuation of the plasma side. Further, there is a problem that the energy loss is high and the efficiency is low. There is a problem.

Accordingly, in the present invention, a silicon (Si) powder is produced by using a direct current (DC) plasma apparatus. As described above, in the case of a direct current (DC) plasma apparatus, The invention is characterized in that a transfer type plasma apparatus is used.

That is, the production of the silicon powder according to the present invention corresponds to a transfer type plasma apparatus using direct current (DC), and it is generally known that a transfer type plasma apparatus using direct current (DC) can be used only for the synthesis of metal powder .

However, the present invention is characterized in that silicon powder, not metal powder, is produced through a transfer type plasma apparatus using direct current (DC), because the silicon powder is a semiconducting material, This is because it has features.

Next, a method of manufacturing a silicon powder according to the present invention includes a step of generating a thermal plasma jet by DC discharge in the transfer type plasma apparatus (S130).

Specifically, referring to FIG. 2, the transfer type plasma apparatus includes a reactor in which a silicon powder base material is vaporized and cooled to form a nano powder; A plasma torch portion for supplying a heat source for vaporizing the silicon powder base material into the reactor; A holder and a crucible for fixing the raw material silicon powder base material; An exhaust unit for exhausting waste gas generated after the reaction; And a DC power source for supplying power to the torch portion.

The torch portion generates an arc by using a tungsten anode in the torch and a silicon powder base material as an anode as an anode, and injects the working gas in a vertical direction.

As shown in FIG. 6, in the present invention, a plasma can be generated by a simple method through a crucible such as a copper rod and a rod of a negative electrode such as a tungsten material. Accordingly, in the present invention, In addition, the present invention does not limit the kind of the transfer type plasma apparatus.

As described above, it is generally known that a transfer type plasma apparatus using direct current (DC) can be used only for the synthesis of metal powders.

However, the present invention is characterized in that silicon powder, not a metal powder, is produced through a transfer type plasma apparatus using direct current (DC) because silicon powder is a semiconducting material.

That is, in the transfer type plasma apparatus, the silicon powder base material is used as the anode. In the case of the silicon powder base material, the silicon powder serves as an insulator at room temperature, and as the temperature rises, the resistance decreases to function as a conductor, In the present invention, since the silicon powder can function as a conductor through the heat applied to the silicon powder, it can serve as an electrode in the transfer type plasma apparatus.

At this time, in order to adjust the heat transfer and injection direction of the silicon powder base material, the torch can be operated in the up, down, left, and right directions within the reactor.

Further, both electrodes may be water-cooled to protect the torch portion from heat.

The reaction tube may comprise a stainless steel double tube with a window.

At this time, in the step of generating the thermal plasma jet, the thermal plasma is an ionized gas composed of electrons, ions, atoms and molecules generated from a plasma torch using a DC arc, It is a state of the fourth material which has extreme physico - chemical properties which are totally different from solid, liquid, and gas in the form of high - speed jet flame with high heat capacity.

The thermal plasma jet is generated by a transfer type plasma apparatus, and in the plasma apparatus, argon gas, air, nitrogen gas or a mixed gas thereof can be used as an operating gas.

Specifically, an argon gas, air, or nitrogen gas may be used as the working gas used in the transfer type plasma apparatus of FIG. 2. In particular, argon gas is preferably used. Since argon is an element of group 8, electrons are easily released by relatively low energy, and inert gas is most effective for generating thermal plasma because it has little effect on chemical reaction.

Since argon plasma gas is inert at high temperatures, it has a small molecular weight and is easy to diffuse heat, thereby increasing the current density of the arc and obtaining a high-temperature plasma.

Next, a method of manufacturing a silicon powder according to the present invention includes a step of melting and vaporizing (or evaporating) the silicon powder base material using the thermal plasma jet (S140).

Specifically, the silicon powder base material is sprayed onto the silicon powder base material while the silicon powder base material is disposed on the crucible, and the silicon powder base material is melted and vaporized by the high-temperature plasma to exist in a vapor phase state.

As described above, the silicon powder base material may be a silicon powder base material in bulk state or a silicon powder base material in powder state. However, in the present invention, the bulk state of the bulk material It is preferable that it is a powder base material.

This is related to this step. In melting and vaporizing the silicon powder base material by using a thermal plasma jet, when the silicon powder base material is in a powder state, the thermal plasma jet causes flaking, Lt; / RTI >

Therefore, in the present invention, it is preferable that the silicon powder base material is a silicon powder base material in a bulk state in order to prevent the base material of the silicon powder from being blown by the thermal plasma jet and causing loss of the base material.

Next, a method of manufacturing a silicon powder according to the present invention includes a step of cooling silicon in the vaporized state to produce silicon nano powder (S150).

That is, the silicon which is melted and vaporized by the high-temperature plasma and is present in a gaseous state is quenched in the inner wall of the reactor and the collecting tube to produce silicon nano powder having a size of nano unit.

Thus, the silicon nano powder according to the present invention can be produced.

Hereinafter, preferred experimental examples according to the present invention will be described. However, the present invention is not limited to the experimental examples.

[Experimental Example 1]

In the transfer type plasma jet apparatus, the raw material silicon powder base material was placed in a crucible, and the plasma was discharged by argon (Ar) gas. Argon gas was filled and the chamber pressure reached about 450 Torr. A plasma discharge was caused between the tungsten anode rod and the copper crucible as the anode. At this time, the plasma current was about 200 A and the voltage between the two electrodes was observed at 50 V. The silicon powder base material was melted by the arc plasma and solidified into a single large mass, which was subsequently vaporized and condensed and cooled by an internally filled arsenic gas to produce a powder in the chamber wall. At this time, the silicon nano powder used was a silicon powder in a waste state from a silicon ingot. The detailed operating conditions are shown in Table 1 below.

The silicon powder base material, which is a raw material, was vaporized by a high-temperature plasma jet, quenched, cooled on the inner wall of the reactor, and made into silicon nano powder.

division Operating condition Plasma power About 200 A, about 10 kW pressure 450 torr Plasma gas argon Raw material Silicon ingot powder Reaction time 5 minutes

[Experimental Example 2]

The procedure of Experimental Example 1 was repeated except that a silicon wafer piece was used instead of the silicon nano powder.

XRD data and FE-SEM photographs of the silicon nano powder prepared in Experimental Example 1 and Experimental Example 2 were obtained.

FIG. 3A is XRD data of a silicon powder from a silicon ingot, and FIGS. 3B and 3C are FE-SEM photographs of a silicon powder from a silicon ingot.

The XRD data of the silicon powder from the silicon ingot of Fig. 3A is for comparison with the silicon powder produced by Experimental Example 1 and Experimental Example 2 above.

Here, referring to FIGS. 3B and 3C, the silicon powder from the silicon ingot was identified as a micrometer-unit powder.

FIG. 4A is XRD data of the silicon nano powder prepared in Experimental Example 1, and FIGS. 4B and 4C are FE-SEM photographs of the silicon nano powder prepared in Experimental Example 1. FIG.

4A and FIG. 3A, the XRD data of the silicon powder from the silicon ingot and the XRD data of the silicon nano powder prepared by the first example are the same or almost similar, It can be confirmed that the nano powder produced by the present invention is pure silicon powder.

Next, referring to FIGS. 4B and 4C, the average particle size of the silicon powder prepared in Experimental Example 1 corresponds to about 50 nm. Thus, the nano-sized silicon powder can be prepared according to Experimental Example 1 can confirm.

FIG. 5A is XRD data of the silicon nano powder prepared in Experimental Example 2, and FIGS. 5B and 5C are FE-SEM photographs of the silicon nano powder prepared in Experimental Example 2. FIG.

5A and FIG. 3A, the XRD data of the silicon powder from the silicon ingot and the XRD data of the silicon nano powder prepared by the example 2 are the same or almost similar to each other, It can be confirmed that the nano powder produced by the present invention is pure silicon powder.

Next, referring to FIGS. 5B and 5C, the average particle size of the silicon powder prepared in Experimental Example 2 was about 50 nm. Thus, the nano-sized silicon powder can be prepared according to Experimental Example 2 can confirm.

According to the above experimental example, it can be confirmed that the silicon nano powder can be easily prepared by the arc plasma discharge method in which the silicon powder base material is evaporated to the plasma arc.

This arc plasma discharge method is not only a relatively simple process but also can produce a large amount of silicon nano powder in a very short time, as can be seen from the above-mentioned process time.

On the other hand, as described above, it is generally known that a transfer type plasma apparatus using direct current (DC) can be used only for the synthesis of metal powder. In the case of silicon powder as the semiconducting material, ) Can be fabricated through a transfer type plasma apparatus using the above-described plasma processing apparatus.

Therefore, it can be seen that the manufacturing method according to the present invention can be extended to the production of semiconducting nano powder, not limited to the production of silicon nano powder.

That is, in the present invention, there is provided a method of manufacturing a semiconductor device, Generating a thermal plasma jet by DC discharge; Melting and vaporizing the semiconductor powder base material using the thermal plasma jet; And cooling the semiconducting material in the vaporized state to produce a semiconducting nano powder, the semiconducting nano powder can be produced.

The method of claim 1, further comprising the step of charging the semiconducting powder preform into a transfer type plasma device after providing the semiconductive powder preform, wherein generating the thermal plasma jet by the DC discharge comprises: And a device is provided.

In this case, the semiconductive material may be a known semiconducting material including silicon (Si) or germanium (Ge), and the present invention does not limit the kind of the semiconductive material.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (5)

Providing a silicon powder preform;
Generating a thermal plasma by DC discharge;
Melting and vaporizing the silicon powder base material using the thermal plasma; And
Cooling the silicon in the vaporized state to produce silicon nano powder,
Further comprising the step of charging the silicon powder preform into the transfer type plasma device after the step of providing the silicon powder preform,
Wherein the step of generating a thermal plasma by the DC discharge is performed through the transfer type plasma device. The method according to claim 1,
Wherein the silicon powder base material is a silicon powder base material in a bulk state or a silicon powder base material in a powder state. delete Providing a semiconducting powder preform;
Generating a thermal plasma by DC discharge;
Melting and vaporizing the semiconductor powder base material using the thermal plasma; And
Cooling the semiconducting material in the vaporized state to produce semiconducting nano powder,
Further comprising the step of charging the semiconductive powder preform into a transfer plasma device after the step of providing the semiconducting powder preform,
Wherein the step of generating the thermal plasma by the DC discharge is performed through the transfer type plasma device.
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