JP2011506251A - SiC material combining α-SiC and β-SiC, manufacturing method, and two-body plasma chamber cathode using the material - Google Patents

Abstract

According to the present invention, after temporarily forming a carbon / α-SiC mixture obtained by mixing an α-SiC powder produced by normal pressure and pressure sintering and a carbon powder, the resistance is adjusted in a high temperature environment in a vacuum. By producing a β-SiC material having resistance corresponding to electrical characteristics by reacting with molten silicon, it has electrical characteristics and excellent mechanochemical characteristics required for parts in the semiconductor manufacturing process. The reaction-sintered β-SiC material composited with α-SiC and β-SiC for semiconductor process parts, which is characterized by high-speed production and low cost, and a method for producing the same.
According to another aspect of the present invention, the reaction sintered β-SiC material is used to form a cathode in a two-body silicon-SiC structure, with high thermal conductivity and low resistance, A two-body plasma chamber cathode having a silicon-SiC structure with improved mechanical properties such as durability and wear resistance is provided.
[Selection] Figure 1

Description

The present invention relates to a method of manufacturing an SIC material having electrical characteristics among SiC materials that have recently been used as components in semiconductor processes, and is a carbon / α- mixture obtained by mixing carbon powder and α-SiC powder. By reacting and impregnating the SiC compact with resistance-adjusted molten silicon, it has excellent mechanical properties, high purity and strength, and electrical characteristics required for semiconductor processes. Reacting sintered SiC material in which α-SiC and β-SiC are combined in addition to low manufacturing cost and high-speed sintering, a manufacturing method thereof, and a silicon-SiC structure two-body type using the reaction sintering material The present invention relates to a plasma chamber cathode.

At present, ceramic products such as graphite, quartz, Al ₂ 0 ₃ , SiC, ALN, and BN are used as jigs and parts in the manufacturing process of ultra-highly integrated Si semiconductors. In the process, quartz, glass, Si and SiC are used as main materials.
Of these, quartz has been the material of high-temperature ceramic parts for semiconductor processes, but the quartz glass has been high in the past, but recently, as the integration of semiconductor devices and the size of Si wafers to be used have increased, quartz glass has become increasingly popular. SiC (silicon carbide), which is excellent in heat, mechanical characteristics, chemical resistance, electrical characteristics, durability, and particle contamination resistance capable of complementing the weak points, is often used.
As a conventional production method of such a SiC material, a silicon secondary gas and a carbon-containing gas are reacted with each other at a high temperature to synthesize SiC, and a gaseous substance is chemically reacted or decomposed in an activated environment. There are a thermal CVD method for producing stable SiC and a plasma CVD method. However, these methods are advantageous in that a SiC material having high purity and high density and excellent characteristics can be produced, but it is difficult to produce a thick product, and the SiC material is expensive. The fact is that it is difficult to apply to semiconductor process parts due to the drawbacks. An example of the SiC material is shown in FIG.
In addition, α-SiC materials manufactured by atmospheric pressure and pressure sintering have excellent thermal, mechanical and chemical resistance properties, but have a high shrinkage ratio after sintering and manufacture large products. It is difficult to control the impurity content in the SiC material because a large amount of sintering aid is used at the time of manufacture. In particular, since it is difficult to adjust the electrical characteristics, Although it can be applied to a simple part type, it is not suitable for a part that is required to have electrical characteristics, and has a drawback that its use is limited.
On the other hand, among the components used in the semiconductor process described above, the plasma chamber cathode used for the wafer etching operation injects a reaction gas into the chamber and applies a current to generate plasma. In addition, as a type of conventional plasma chamber cathode, a cathode made of a single silicon material having a large number of gas inlets or a cathode having various configurations formed by bonding carbon material, aluminum, etc. to silicon by bonding or bolts. Many are disclosed in the literature.
For example, in the “bonding structure of cathode electrodes in a plasma etching apparatus” disclosed in Korean Patent Registration No. 10-0708321, bonding is performed by inserting a silicon electrode and a graphite electrode constituting the cathode into a binding substrate. I tried to solve the problem due to the decrease in bonding force due to peeling inside, but the graphite material easily deformed under high temperature and high pressure environment inside the chamber and damaged the binding substrate and bonding part, Since the contact between the graphite electrode and the silicon electrode is unstable, there is a problem that generation of particles due to friction is a concern.
Further, as an attempt to solve the problems that occur in the prior art, in the plasma generating electrode and the plasma processing apparatus described in Korean Patent Laid-Open No. 10-2007-0077048, silicon carbide is impregnated with silicon. The following CVD-silicon carbide material can be applied to the cathode to have excellent mechanical properties and high uniformity. However, the CVD-silicon carbide employed in the above-described technique requires a large amount of expensive sintering aids to be used for sintering the raw material during production, which causes boiling of the production cost of the cathode, As a result of increasing the content of impurities in the SiC sintered body due to the introduction of the sintering aid, there is an inconvenience that it becomes difficult to apply to the wafer process.

Korean Registered Patent No. 10-0708321 Korean Published Patent No. 10-2007-0077048

The present invention has been made to solve the problems that occur in the prior art, and its purpose is to have excellent mechanical and electrical characteristics, and is suitable for use as a semiconductor process component. The present invention provides a reaction sintered SiC material in which α-SiC and β-SiC are combined, and a method for producing the same, which can reduce the manufacturing cost of the material. Another object of the present invention is to maintain the electrical characteristics by applying the reaction sintered SiC material in which the α-SiC and β-SiC are combined to the plasma chamber cathode in the semiconductor process parts. It is an object of the present invention to provide a two-body plasma chamber cathode made of a silicon-SiC material that has mechanical properties suitable for high-temperature and high-pressure semiconductor processes and is also economical.

In order to achieve the above object, the present invention includes a step of mixing an α-SiC powder produced by atmospheric pressure and pressure sintering with a carbon powder to obtain a carbon / α-SiC mixture, and the carbon / α A step of obtaining a carbon / α-SiC molded body by pressurizing a SiC mixture at a high temperature, and a silicon having a controlled resistance to which the carbon / α-SiC molded body is added at a high temperature of 1400 ° C. to 2000 ° C. in a vacuum And a step of impregnating with, and a method of producing a reaction sintered SiC material in which α-SiC and β-SiC are combined. The present invention also provides a plasma chamber cathode having an electrical characteristic and α-SiC and β-SiC, in which a SiC electrode made of a reaction sintered SiC material manufactured by the above method and a silicon electrode are combined. .

According to the present invention, high-purity α-SiC and β having high electrical properties according to usage, excellent strength, fine crystals, and extremely low impurity content. -Reaction sintered SiC material in which SiC is combined can be manufactured. In addition, according to the present invention, there is no or almost no change in dimensions during sintering of the material, high-speed sintering by accidental exothermic reaction is performed, and sintering is possible at a relatively low temperature. There is an effect that the productivity of the reaction sintered SiC material can be improved.
Furthermore, according to another aspect of the present invention, a SiC electrode made of a reaction sintered SiC material, which is produced by the above-described method and is a composite of α-SiC and β-SiC having electrical characteristics, is used as a lower silicon electrode. Combined to form a two-body cathode, the electrical characteristics are stable when used as an electrode, and the joint part due to the difference in thermal conductivity with a silicon electrode when used in a high-temperature, high-pressure semiconductor wafer process Can prevent damage. In addition, the SiC electrode has excellent strength, thus extending the service life of the cathode, improving wear resistance and preventing the generation of particles on the wafer, as well as good electrical conductivity due to its high thermal conductivity and low resistance properties. As a result, it is possible to produce a high-purity wafer. As a result, the production yield of the wafer can be increased.

The process sequence diagram which shows the manufacturing method of the beta-SiC sintered compact by the present invention, The operation process figure which shows each process of the manufacturing method of the beta-SiC sintered compact by the present invention, The operation process figure which shows each process of the manufacturing method of the beta-SiC sintered compact by the present invention, 1 is a perspective view and a cross-sectional view showing a plasma chamber cathode according to a preferred embodiment of the present invention; Sectional drawing which shows the plasma chamber cathode by other embodiment of this invention, FIG. 4 is a cross-sectional view showing the coupling between the plasma chamber cathode and the upper plate according to the present invention. An example of a SiC material is shown. α-SiC is shown. Indicates reactive sintered SiC material

The present invention relates to a method of manufacturing a SiC material that has recently been widely used as a component for a semiconductor manufacturing process in a high-temperature / high-pressure environment, and a two-body plasma chamber cathode having a silicon-SIC structure using the SiC material. According to one aspect of the present invention, in the method for producing a SIC sintered body material, a step of mixing an α-SiC powder produced by normal pressure and pressure sintering with a carbon powder to obtain a carbon / α-SiC mixture. Pressing the carbon / α-SiC mixture at a high temperature to obtain a carbon / α-SiC molded body, and adding the carbon / α-SiC molded body at a high temperature of 1400 ° C. to 2000 ° C. in a vacuum. And a step of impregnating with resistance-controlled silicon, and a method for producing a reaction sintered SiC material in which α-SiC and β-SiC are combined.
The present invention also provides a reaction sintered SiC material that is a composite of α-SiC and β-SiC produced by the above method.
Furthermore, according to another aspect of the present invention, a plasma chamber cathode used in a semiconductor wafer etching process includes a lower silicon electrode and an SiC electrode coupled to the upper portion of the silicon electrode, and α-SiC and β- A two-body plasma chamber cathode having a silicon-SiC structure made of a reaction sintered SiC material combined with SiC is provided.
The configuration and embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, FIG. 1 is a process sequence diagram showing a method for producing a reaction sintered SiC material in which α-SiC and β-SiC are combined according to a preferred embodiment of the present invention, and FIGS. 2 and 3 show the present invention. It is an operation process figure showing each process of the manufacturing method of the beta-SiC sintered compact by a suitable embodiment. According to the method for producing a β-SiC material according to a preferred embodiment of the present invention, as shown in FIG. 1, an α-SiC powder produced by normal pressure and pressure sintering is mixed with carbon powder to produce carbon / Obtaining an α-SiC mixture (S11), pressing the carbon / α-SiC mixture at a high temperature to obtain a carbon / α-SiC molded body (S12), and vacuuming the carbon / α-SiC molded body And impregnating by reacting with molten silicon at a high temperature of 1400 ° C. to 2000 ° C. (S13).
Hereinafter, the present invention will be described in more detail with reference to examples according to respective process steps.
-Formation of carbon / α-SiC mixture-
Generally, the α-SiC material contains a large amount of impurities in the sintered body because a sintering aid is added during sintering, and has a high internal porosity, so it is suitable for a semiconductor process in a high temperature environment. Is unsuitable. α-SiC is shown in FIG.
In order to improve the properties of the α-SiC material, powdered α-SiC powder is mixed with carbon powder to form a carbon / α-SiC mixture for sintering.
The carbon powder preferably has a particle size of 0 to 50 μm, and the α-SiC powder is a mixture of SiO ₂ and petroleum coke using a large-sized Atchison furnace, and a current is applied to 2200 ° C. to It is preferable to use an α-SiC material produced by reacting at a high temperature of 2400 ° C, and the α-SiC powder is preferably 1 to 100 µm or less.
Further, in the above step, silicon and the carbon component of the carbon / α-SiC mixture in the process of manufacturing a reaction sintered SiC material in which α-SiC and β-SiC are combined by impregnating a mixture of silicon described later. May be impregnated with silicon powder and dopant powder each having a particle diameter of 0 to 50 μm or less. In this case, it is preferable that 0.1 to 20 wt% of the silicon powder and 0.1 to 10 wt% of the dopant powder are mixed based on the total weight of the carbon / α-SiC mixture.
-Formation of carbon / α-SiC molded body-
A carbon / α-SiC compact is formed by pressurizing a mixture of carbon and α-SiC obtained by mixing the powder of the α-SiC material and carbon powder using a press or CIP.
-Manufacture of reaction sintered SiC sintered compact combining α-SiC and β-SiC-
When silicon is applied to the carbon / α-SiC molded body formed as described above and heated to a high temperature in a vacuum state, silicon and carbon are reacted while silicon is impregnated in the voids of the molded body, and β-SiC is reacted. As a result, α-SiC is surrounded by β-SiC and silicon, and a reaction sintered SiC material in which α-SiC and β-SiC having electrical properties are combined is manufactured.
In the above, the temperature for heating the carbon / α-SiC molded body infiltrated with silicon is preferably 1400 ° C. to 2000 ° C., which is lower than the α-SiC sintering temperature by normal pressure and pressurization, Reaction of composite of α-SiC and β-SiC having a compact structure and electrical characteristics without pores, where the whole silicon is impregnated by the capillary pressure by vacuum and the dead weight of silicon between the mixture of carbon and α-SiC A sintered SiC material is produced. This reactive sintered SiC is shown in FIG.
In this process, boron added to the silicon to be impregnated is given electrical properties by the reaction of a mixture of carbon and α-SiC, or carbon and α-SiC, silicon, a mixture of dopant and silicon having impregnation resistance. By adjusting the resistance by adjusting the amount of boron) and impregnating the resistance-adjusted silicon, the electrical resistance of the reaction sintered SiC material in which α-SiC and β-SiC are combined is adjusted.
For reference, boron, the amount of which is added to adjust the resistance of silicon, can increase the reactivity with carbon by decreasing the resistance of silicon as the amount of addition increases. A material having a required resistance or a low resistance can be manufactured by reacting silicon having a controlled resistance with carbon of a carbon / α-SiC molded body.
Here, when carbon, α-SiC, silicon, and a dopant are mixed, the resistance-adjusted silicon 30 based on the total weight of the reaction-sintered SiC material that is a composite of α-SiC and β-SiC to be produced. It is preferable to use ˜80 wt% and 0.1˜10 wt% which determines the resistance of silicon.
-Characteristics of reaction sintered SiC material combining α-SiC and β-SiC- (FIG. 9)
As described above, the reaction-sintered SiC material that is a composite of α-SiC and β-SiC produced by the production method of the present invention has little or no dimensional change during reaction sintering, and carbon and α -The mixture structure produced by the reaction of SiC plays a role of increasing the strength of the material. In addition, the reaction-sintered SiC material that is a composite of α-SiC and β-SiC manufactured by the manufacturing method of the present invention is impregnated with silicon between the mixture structures and has high strength, and is distributed as agglomerates of fine particles. In addition to obtaining a compact sintered body having no pores, the content of impurities can be greatly reduced since a sintering aid for promoting sintering of the raw material powder is not added to the SiC material.
In addition, since it can be heated at a lower temperature than the manufacturing method by normal pressure and pressurization, and self-heating reaction occurs and high-speed sintering is performed, the size and shape of β-SiC sintered body after reaction sintering There is an advantage that the work speed is fast. In particular, the resistance of the SiC material can be adjusted so that it can be manufactured to meet desired electrical characteristics. As a result, it can be used in a wide variety of semiconductor processes compared to SiC, which has only mechanochemical properties. is there.
Therefore, according to the present invention, the semiconductor process has a high temperature environment and corrosion resistance, in particular, has electrical characteristics required for the semiconductor etching process, and has high purity, high density, and high strength. SiC material can be manufactured. In addition, since it is possible to produce SiC material having excellent mechanical properties at high speed, there is an effect that the production cost can be reduced, and thereby α-SiC having suitable electrical characteristics in semiconductor production equipment and There is a feature that a reaction sintered SiC material combined with β-SiC can be manufactured.
Furthermore, according to another aspect of the present invention, α-SiC and β-SiC manufactured by the manufacturing method of the present invention are combined on the top of a silicon electrode in a cathode used for a wafer etching process in a semiconductor process. There is provided a two-body plasma chamber cathode made of silicon-SiC in which SiC electrodes made of reaction-sintered SiC material are aligned and bonded to the upper and lower sides thereof. Hereinafter, the configuration and operation of the two-body plasma chamber cathode having a silicon-SiC structure according to the present invention will be described.
4 is a perspective view and a sectional view showing a plasma chamber cathode according to a preferred embodiment of the present invention, FIG. 5 is a sectional view showing a plasma chamber cathode according to another embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view showing the coupling between the plasma chamber cathode and the upper plate according to the present invention. As shown in FIG. 4, the plasma chamber cathode according to a preferred embodiment of the present invention is made of a reaction sintered SiC material in which α-SiC and β-SiC manufactured according to the present invention are combined on a lower silicon electrode 20. The two SiC electrodes 10 are arranged side by side and are joined together vertically. At this time, the silicon electrode 20 and the SiC electrode 10 may be coupled by the elastomer bonding E or the coupling bolt B.
Further, as shown in FIG. 5, the cathode 100 formed by combining the silicon electrode 20 and the SiC electrode 10 is made into a single body, and the upper plate 30 arbitrarily formed inside the chamber as shown in FIG. Or the outer ring 110 may be detached from the outside of the cathode, and the cathode and the outer ring may be separately coupled to the upper plate 30 as shown in FIG. The outer cathode 110 may be configured so as to be coupled in a funnel shape at a predetermined interval on the outer side of the central cathode 100.
For this reason, according to the plasma chamber cathode of the present invention having the above-described configuration, excellent electrical characteristics, thermal conductivity, hardness, and acid resistance of the reaction sintered SiC material SiC electrode 10 composited with α-SiC and β-SiC. By providing mechanical properties such as heat resistance, wear resistance, corrosion resistance, and high-temperature stability, the bonding bolt B is deformed by deformation of the silicon electrode 20 bonded to the lower portion and the upper plate 30 bonded to the upper portion. By using a reaction sintered SiC material that is a composite of high-purity α-SiC and β-SiC, particles are generated during wear due to deformation of the silicon electrode 20 and the upper plate 30. Can be prevented. In addition, according to the plasma chamber cathode of the present invention having the above configuration, the SiC electrode 10 can be manufactured to have a low electrical resistance of 0.10 hm-cm or less and a high thermal conductivity, and the upper plate 30 As a result, it is possible to produce a high-quality plasma by improving the conductivity when a voltage is applied to the substrate, and to produce a highly integrated circuit on the wafer with a uniform plasma density.

10: SiC electrode 20: Silicon electrode 30: Upper plate 100: Cathode 110: Outer ring

Claims (8)

Mixing an α-SiC powder produced by normal pressure and pressure sintering with a carbon powder to obtain a carbon / α-SiC mixture (S11);
Pressing the carbon / α-SiC mixture at a high temperature to obtain a carbon / α-SiC molded body (S12);
Reacting and impregnating the carbon / α-SiC molded body with a controlled-resistance silicon added at a high temperature of 1400 ° C. to 2000 ° C. in a vacuum (S13);
Of reaction-sintered SiC material in which α-SiC and β-SiC are mixed. The α-SiC powder uses an α-SiC material produced by mixing SiO ₂ and petroleum coke using a large Atchison furnace and reacting them at a high temperature of 2200 ° C. to 2400 ° C. by passing an electric current. The method of claim 1, characterized in that: In the step of obtaining the carbon / α-SiC mixture by mixing the α-SiC powder with the carbon powder (S11), the carbon / α-SiC mixture having a particle diameter of 0 to 50 μm is used as a reference based on the total weight. The α-SiC according to claim 1, wherein 1 to 20 wt% silicon powder and 0.1 to 10 wt% dopant powder are mixed to increase the reactivity between carbon and silicon in the silicon impregnation process. A method for producing a reaction sintered SiC material in which β-SiC is combined. In the step (S11) of obtaining the carbon / α-SiC mixture by mixing the α-SiC powder with the carbon powder, the α-SiC powder having a particle diameter of 1 to 100 μm and the carbon powder having a particle diameter of 0 to 50 μm are used. The method according to claim 1. In the step (S13) of reacting the carbon / α-SiC molded body with the resistance-adjusted silicon, the resistance is determined based on the total weight of the reaction-sintered SiC material in which α-SiC and β-SiC are combined. 2. The method according to claim 1, wherein the electrical resistance of the reaction sintered SiC material is adjusted by adding 30 to 80 wt% of silicon with adjusted and 0.1 to 10 wt% of dopant. A SiC material used as a component in a semiconductor process in which α-SiC and β-SiC are combined,
The SiC raw material manufactured by the method in any one of Claim 1 to 4. In a two-body plasma chamber cathode that injects a reaction gas into the chamber in the semiconductor wafer etching process and applies a current to generate plasma,
A reaction sintered SiC material SiC electrode (10) manufactured by the method according to any one of claims 1 to 4 is bonded to an upper portion of a silicon electrode (20), and α-SiC and β-SiC are combined. Body plasma chamber cathode. The two-body type plasma chamber cathode according to claim 7, wherein the silicon electrode (20) and the SiC electrode (10) are bonded by either one of an elastomer bonding (E) and a bonding bolt (B). .

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