KR20120137183A - Silicon carbide sintered body, method for manufacturing the same and susceptor including the same - Google Patents

Abstract

PURPOSE: A sintered silicon carbide with high purity by excluding the use of sintering gradient material, a manufacturing method thereof and a susceptor including the same are provided to enhance strength and heat resistance. CONSTITUTION: A sintered silicon carbide with high purity comprises 95-100 wt% of beta phase silicon carbide. The diameter of the grain of the silicon carbide is 0.1-3 micro meters. The silicon carbide sintered body has the density of 3--3.15g/cm^3. The silicon carbide sintered body has the thermal conductivity of 180-200W/m·K. A manufacturing method of the silicon carbide sintered body comprises the following steps: placing the silicon carbide pulverized body(30) in a mold(10); heat treating the silicon carbide pulverized body under the first pressure and temperature; and pressing the silicon carbide pulverized body under the second pressure and temperature. The second pressure is higher than the first pressure, and the second temperature is higher than the first temperature. [Reference numerals] (AA, BB) Heat pressure

Description

Silicon carbide sintered body, a manufacturing method thereof and a susceptor including the same {SILICON CARBIDE SINTERED BODY, METHOD FOR MANUFACTURING THE SAME AND SUSCEPTOR INCLUDING THE SAME}

The embodiment relates to a silicon carbide sintered body, a method of manufacturing the same, and a susceptor including the same.

In a semiconductor process or the like, a substrate or a wafer is placed on a susceptor for deposition, etching, and the like. Such a susceptor may be made of silicon carbide having high heat resistance to withstand conditions such as high temperature. A general susceptor is formed by depositing a high purity silicon carbide layer on a body containing graphite.

When a sintering aid of metal is added to form a sintered body formed of silicon carbide, the substrate or wafer may be contaminated by the sintering aid that is an impurity. If the sintering aid of the metal is not added, the sintered density may be lowered and the durability of the sintered compact may be lowered.

The embodiment is to provide a silicon carbide sintered body having an improved strength and heat resistance, having a high purity, a method of manufacturing the same, and a susceptor including the same.

The silicon carbide sintered body according to the embodiment includes 95 wt% to 100 wt% of beta phase silicon carbide.

In this case, the diameter of the grains of silicon carbide may be 0.1㎛ to 3㎛.

In addition, the silicon carbide sintered body according to the embodiment may have a density of about 3 g / cm 3 to about 3.15 g / cm 3.

In addition, the silicon carbide sintered body according to the embodiment may have a thermal conductivity of about 180 W / m · K to about 200 W / m · K.

In addition, the susceptor according to the embodiment includes the silicon carbide sintered body.

Method for producing a silicon carbide sintered body according to the embodiment comprises the steps of placing a plurality of silicon carbide powder in a mold; Heat treating the silicon carbide powder under a first pressure and a first temperature; And pressing the silicon carbide powder under a second pressure and a second temperature.

At this time, the second pressure is higher than the first pressure, and the second temperature is higher than the first temperature.

The silicon carbide powder is a method for producing a silicon carbide sintered body having a beta phase.

The silicon carbide powder may be mixed with a resin containing carbon and disposed in the mold in the form of granules.

The first temperature may be 1500 ° C. to 1800 ° C., and the first pressure may be 0.7 atm to 2 atm.

In addition, the silicon carbide powder may have a central particle diameter of about 1.2 μm to about 2.2 μm.

The second temperature may be 2200 ° C. to 2800 ° C., and the second pressure may be 10 MPa to 50 MPa.

The silicon carbide sintered body according to the embodiment is made of almost beta phase silicon carbide and has a small grain size. Accordingly, the silicon carbide sintered body according to the embodiment may have high density and thermal conductivity.

In particular, in the heat-treating step, silicon carbide particles having a very small diameter, for example, a diameter of several nm to several hundred nm, of the silicon carbide powder may be diffused and / or grain grown to each other from about 0.5 μm to several Silicon carbide particles of a diameter of micrometers.

Accordingly, in the process of manufacturing the silicon carbide sintered body according to the embodiment, silicon carbide particles having a very small diameter can also form a sintered body by strong bonding.

Therefore, the silicon carbide sintered body according to the embodiment may have improved mechanical strength and heat resistance.

1 is a block diagram illustrating a method of manufacturing a silicon carbide sintered body according to an embodiment.
2 is a schematic view showing a hot press sintering apparatus for producing a silicon carbide sintered body according to an embodiment.
3 and 4 are views illustrating a process of manufacturing the silicon carbide sintered body according to the embodiment.

In the description of the embodiments, it is described that each substrate, film, electrode, particle or layer or the like is formed on or under the "on" of each substrate, electrode, film, particle or layer or the like. In the case, “on” and “under” include both being formed “directly” or “indirectly” through other components. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

1 is a block diagram illustrating a method of manufacturing a silicon carbide sintered body according to an embodiment. 2 is a schematic view showing a hot press sintering apparatus for producing a silicon carbide sintered body according to an embodiment. 3 and 4 are views illustrating a process of manufacturing the silicon carbide sintered body according to the embodiment.

Referring to FIG. 1, the method of manufacturing the silicon carbide sintered body according to the present embodiment may include a raw material mixing step (ST10), a granulation step (ST20), a heat treatment step (ST30), and a pressure forming step (ST40). . In this embodiment, the silicon carbide sintered body is formed of a silicon carbide sintered body by a hot pressure sintering method. This will be described in more detail as follows.

In the raw material mixing step ST10, the silicon carbide powder is dispersed in the solvent.

The central particle diameter of the silicon carbide powder may be about 1.2 μm to about 2.2 μm. The silicon carbide powder may be β-phase silicon carbide. In more detail, the silicon carbide powder may include beta-phase silicon carbide having a purity of about 5N (99.999 wt%) or more.

In addition, the silicon carbide powder may be mixed in the solvent with a resin containing carbon. Phenolic resin may be used as the resin. In addition, an alcohol or an aqueous material may be used as the solvent. Examples of the alcohol-based substance include methanol, ethanol, and isopropyl alcohol (IPA), and water may be used as the aqueous substance. However, the embodiment is not limited thereto.

Subsequently, in the granulation step ST20, the mixed raw materials are granulated. In one example, a spray dryer may be used to granulate the mixed raw materials. In this case, the granules may have a size of about 50 μm to about 200 μm.

Thereafter, the granulated silicon carbide powder is placed in a hot pressure sintering apparatus. Referring to FIG. 2, the hot pressure sintering apparatus includes a mold 10, a first press part 21, and a second press part 22. In addition, the hot pressure sintering apparatus may further include a heat generating unit for applying heat in the mold 10.

The mold 10 includes a space for accommodating the raw material to be molded. The first press part 21 and the second press part 22 face each other. The first press part 21 and the second press part 22 are inserted into the mold 10.

As shown in FIG. 3, the granulated silicon carbide powder 30 is disposed in the mold 10. In more detail, the granulated silicon carbide powder 30 is disposed between the first press part 21 and the second press part 22.

Thereafter, the granulated silicon carbide powder 30 is heat-treated (ST30). The granulated silicon carbide powder 30 may be heat treated at a first temperature and a first pressure. The first temperature may be about 1500 ° C to about 1800 ° C. In more detail, the first temperature may be about 1600 ° C to about 1700 ° C. In addition, the first pressure may be about 0.7 atm to about 2 atm. In more detail, the first pressure may be atmospheric pressure. That is, in the state in which the second press part 22 is opened, the granulated silicon carbide powder 30 may be heat treated. Alternatively, the granulated silicon carbide powder 30 may be heat-treated in a state of being slightly pressed by the first press part 21 and the second press part 22.

The heat treatment step ST30 may be performed for about 30 minutes to about 2 hours. In more detail, the heat treatment step ST30 may be performed for about 1 hour to about 90 minutes.

In this heat treatment step (ST30), the silicon carbide particles having a very small diameter of the silicon carbide powder may be grown into silicon carbide particles having a diameter of about 0.5 ㎛ to several ㎛ through diffusion and / or grain growth. . For example, through the heat treatment step, silicon carbide particles having a diameter of about 10 nm to about 100 nm may be grown into silicon carbide particles having a diameter of about 0.5 μm to several μm.

By such a heat treatment step (ST30), the sinterability of the particles of the silicon carbide powder is too small can be improved. In addition, by the heat treatment step (ST30), problems such as explosion due to the fine powder that can be generated when the particle diameter is less than 30nm can be solved.

Subsequently, in the pressure forming step ST40, the heat treated silicon carbide powder 30 may be hot pressed to form a silicon carbide sintered body having a desired shape. The granulated silicon carbide powder is press molded at a second temperature and a second pressure. That is, as shown in FIG. 4, the granulated silicon carbide powder 30 is pressed by the first press part 21 and the second press part 22, and at the same time by the heat generating part. The granulated silicon carbide powder 30 is heated.

The second temperature is higher than the first temperature. For example, the second temperature may be about 2100 ° C. or more. In more detail, the second temperature may be about 2200 ° C to about 2800 ° C.

The second pressure is higher than the first pressure. For example, the second pressure may be about 10 MPa to about 50 MPa.

The pressure molding step ST40 may last for about 7 hours or more. In more detail, the pressure forming step may last for about 7 hours to about 12 hours.

Through the pressure forming step ST40, a silicon carbide sintered body of a desired shape may be formed. For example, the silicon carbide sintered body having a disc shape may be formed through the pressure molding step ST40.

Thereafter, the silicon carbide sintered body is cooled, and pressure release may be performed at a temperature of about 1500 ° C.

As described above, through the heat treatment step, the sinterability and formability of the silicon carbide particles having a very small particle size are improved. Accordingly, the silicon carbide sintered body according to the embodiment may have improved mechanical strength.

In addition, the method of manufacturing the silicon carbide sintered body according to the embodiment may improve the sinterability through the heat treatment step. Accordingly, in the method of manufacturing the silicon carbide sintered body according to the embodiment, the silicon carbide sintered body can be formed without using a sintering aid. Therefore, the silicon carbide sintered body according to the embodiment may have improved purity.

In particular, the silicon carbide sintered body according to the embodiment may be formed by silicon carbide powder containing beta phase silicon carbide. Therefore, the silicon carbide sintered body according to the embodiment may include beta phase silicon carbide. In more detail, the silicon carbide sintered body according to the embodiment may include beta phase silicon carbide at a ratio of about 95 wt% to about 100 wt%. More specifically, the silicon carbide sintered body according to the embodiment may include beta-phase silicon carbide at a rate of about 99 wt% to about 100 wt%. In more detail, the silicon carbide sintered body according to the embodiment may include about 99 wt% to about 99.999 wt% of beta phase silicon carbide.

As such, the silicon carbide sintered body according to the embodiment is made of almost beta silicon carbide, and thus may have high mechanical strength and heat resistance.

In addition, the silicon carbide sintered body according to the embodiment uses silicon carbide powder having a small central particle diameter. The central particle diameter of the silicon carbide powder may be about 1.2 μm to about 2.2 μm. As such, as the central particle diameter of the silicon carbide powder becomes smaller, the proportion of the fine powder having a particle diameter of about 10 nm to about 100 nm may increase. As described above, the problem of the fine powder generated during sintering is solved by the heat treatment step.

As a result, the method of manufacturing the silicon carbide sintered body according to the embodiment may provide a silicon carbide sintered body having a fine grain size. In more detail, the diameter of the grains of the silicon carbide sintered body according to the embodiment may be about 0.1 μm to about 3 μm.

As such, the silicon carbide sintered body according to the embodiment may have a fine grain size and thus may have an improved density and thermal conductivity. For example, the density of the silicon carbide sintered body according to the embodiment may be about 3 g / cm 3 to about 3.15 g / cm 3. In addition, the thermal conductivity of the silicon carbide sintered body according to the embodiment may be about 180 W / m ~ K to about 200 W / m ~ K.

In addition, the silicon carbide sintered body according to the embodiment may be used for various purposes. For example, the silicon carbide sintered body according to the embodiment may be used as a susceptor for supporting or receiving a substrate or a wafer in a semiconductor process.

In addition, the features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Experimental Example

To the solvent of IPA, 10 weight% of phenolic resins and the silicon carbide powder (beta phase) of 1.7 micrometers of central particle diameters were added and mixed by 90 weight%. The mixed raw materials were then granulated using a spray dryer. Subsequently, the granulated raw material was charged to a hot pressure sintering apparatus, and then heat-treated at a temperature of about 1650 ° C. at atmospheric pressure for about 1 hour. Then, the silicon carbide sintered body was formed by hot pressing at a pressure of about 40 MPa at a temperature of about 2290 ° C.

Comparative example

The experiment was carried out except that the core particle diameter of the silicon carbide powder was about 4 µm, alumina was added at a rate of about 9 w% as the sintering aid, the silicon carbide powder was added at a rate of about 81 wt%, and the heat treatment step was omitted. The same procedure was followed.

result

As shown in Table 1 below, the silicon carbide sintered body of the experimental example was found to have a longer life when used as a susceptor. In addition, it was found that the silicon carbide sintered body of the experimental example had higher density and thermal conductivity.

Grain Diameter (μm) Thermal conductivity
(W / m? K) Density (g / cm 3) Cycle Experimental Example 2.5 190 3.10 200 Comparative example 5.0 127 2.90 30

Claims (12)

A silicon carbide sintered body comprising 95 wt% to 100 wt% of beta phase silicon carbide. The silicon carbide sintered body according to claim 1, wherein the grain size of the silicon carbide is 0.1 µm to 3 µm. The silicon carbide sintered body according to claim 1, comprising 99 wt% to 100 wt% of beta phase silicon carbide. The silicon carbide sintered body according to claim 1, having a density of 3 g / cm 3 to 3.15 g / cm 3. The silicon carbide sintered body according to claim 1, which has a thermal conductivity of 180 W / m? K to 200 W / m? K. Disposing silicon carbide powder in the mold;
Heat treating the silicon carbide powder under a first pressure and a first temperature; And
Pressing the silicon carbide powder under a second pressure and a second temperature,
And said second pressure is higher than said first pressure and said second temperature is higher than said first temperature. The method of claim 6, wherein the silicon carbide powder has a beta phase. The method of claim 6, wherein the silicon carbide powder is mixed with a resin containing carbon and disposed in the mold in the form of granules. The method of claim 6, wherein the first temperature is 1500 ° C. to 1800 ° C., and the first pressure is 0.7 atm to 2 atm. The method for producing a silicon carbide sintered body according to claim 6, wherein the silicon carbide powder has a central particle diameter of 1.2 µm to 2.2 µm. The method of claim 6, wherein the second temperature is 2200 ° C. to 2800 ° C., and the second pressure is 10 MPa to 50 MPa. A susceptor comprising a sintered body comprising 95 wt% to 100 wt% of beta phase silicon carbide.

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