KR20130048440A - Apparatus and method for deposition - Google Patents

Abstract

PURPOSE: A deposition apparatus and a deposition method are provided to preheat reaction gas or carrier gas to a temperature similar to a reaction temperature by using a heating member, and to prevent the nonuniformity and the rapid decrease of temperature in a susceptor. CONSTITUTION: A susceptor accommodates a substrate arranged in a chamber(100). The susceptor includes an upper plate(210), a lower plate, and a side plate. A source gas line(300) supplies the source gas for forming a thin film on the substrate to the susceptor. A first heating member heats the source gas line. A second heating member(600) heats the source gas line and the susceptor. A wafer holder(400) is arranged in the susceptor to support a wafer(W).

Description

Evaporation apparatus and deposition method {APPARATUS AND METHOD FOR DEPOSITION}

Embodiments relate to deposition apparatus and deposition methods.

In general, chemical vapor deposition (CVD) is widely used as a technique for forming various thin films on a substrate or a wafer. The chemical vapor deposition method is a deposition technique involving a chemical reaction, which uses a chemical reaction of a source material to form a semiconductor thin film, an insulating film, and the like on the wafer surface.

Such chemical vapor deposition methods and deposition apparatuses have recently attracted attention as a very important technology among thin film formation technologies due to miniaturization of semiconductor devices, development of high efficiency, high power LEDs, and the like. It is currently used to deposit various thin films such as silicon films, oxide films, silicon nitride films or silicon oxynitride films, tungsten films and the like on a wafer.

In order to grow the silicon carbide epitaxial layer on the wafer or the substrate through the chemical vapor deposition method, the reaction gas is supplied into the susceptor and deposited on the wafer.

In this case, a large amount of reactant gas and a carrier gas are supplied to the source gas line that introduces the reaction gas into the susceptor, and flows into the susceptor through the line at a high speed.

However, since the reaction gas or carrier gas is supplied at room temperature, and ionization occurs at a limited heating site near the susceptor, there is a problem that the amount of reaction gas is ionized and the reaction gas that is undecomposed increases. Accordingly, there is a problem in that the efficiency of epi growth is lowered.

Accordingly, there is a need for a deposition apparatus and a deposition method capable of ionizing a reaction gas even near the source gas line.

Embodiments provide a deposition apparatus and a deposition method capable of increasing the amount of reaction gas to be ionized.

Deposition apparatus according to the embodiment, the chamber; A susceptor accommodated in the chamber to receive a substrate; A source gas line connected to the susceptor and introducing a source gas into the susceptor to form a thin film on the substrate; A first heating member for heating the source gas line; And a second heating member for heating the source gas and the susceptor.

Deposition method according to the embodiment, the step of heating the reaction gas inside the source gas line; Heating the reaction gas inside a susceptor; And reacting the reaction gas with a substrate.

The deposition apparatus and the deposition method according to the embodiment preheat the reaction gas outside the susceptor by a predetermined temperature or more before heating the reaction gas inside the susceptor. That is, the deposition apparatus may preheat the reaction gas or the carrier gas passing through the source gas line at a temperature similar to the reaction temperature by the heating member surrounding the source gas line.

Accordingly, by reducing the temperature difference between the reaction gas or the carrier gas flowing in the source gas line and the susceptor, it is possible to prevent a sudden temperature decrease and temperature unevenness in the susceptor.

Accordingly, the deposition apparatus and the deposition method according to the embodiment can produce a silicon carbide wafer of high efficiency and a silicon carbide epitaxial wafer process.

1 is a schematic view showing a silicon carbide epitaxial growth apparatus according to an embodiment.
2 is an exploded perspective view showing a deposition unit.
3 is a perspective view illustrating a deposition unit.
4 is a cross-sectional view illustrating the deposition unit according to the first embodiment, cut along the line AA ′ in FIG. 3.
FIG. 5 is a cross-sectional view illustrating a deposition unit in accordance with a second embodiment cut along the line AA ′ in FIG. 3.
6 shows a process flow of silicon carbide epilayer growth.

In the description of embodiments, each layer, region, pattern, or structure may be “on” or “under” the substrate, each layer, region, pad, or pattern. Substrate formed in ”includes all formed directly or through another layer. Criteria for the top / bottom or bottom / bottom of each layer will be described with reference to the drawings.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

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

1 is a schematic diagram showing an example of a silicon carbide epitaxial layer growth apparatus according to an embodiment.

Referring to FIG. 1, the silicon carbide growth apparatus according to the embodiment includes a carrier gas supply unit 10, a reaction gas supply unit 30, and a deposition unit 40.

The carrier gas supply unit 10 supplies a carrier gas to the reaction gas supply unit 30. The carrier gas has very low reactivity. Nitrogen, an inert gas, etc. are mentioned as an example of the said carrier gas. In particular, the carrier gas supply unit 10 may supply the carrier gas to the reaction gas supply unit 30 through the first supply line 21.

The reaction gas supply unit 30 generates the reaction gas. In addition, the reaction gas supply unit 30 receives a liquid 31 for producing the reaction gas. For example, the liquid 31 may be evaporated to form the reaction gas.

An end of the first supply line 21 may be immersed in the liquid 31. Accordingly, the carrier gas is supplied into the liquid 31 through the first supply line 21. Accordingly, bubbles including the carrier gas may be formed in the liquid 31.

The liquid 31 and the reaction gas may include a compound including silicon and carbon. For example, the liquid 31 and the reaction gas may include methyltrichlorosilane (MTS).

The reaction gas supply unit 30 may include a heating unit for applying heat to the liquid 31. The heating unit may heat the liquid 31 to evaporate the liquid 31. By the heat generating portion, the amount of reaction gas to be evaporated can be appropriately adjusted according to the amount of heat applied.

The reaction gas supply unit 30 supplies the reaction gas to the deposition unit 40 through the second supply line 22. That is, the reaction gas is supplied to the deposition unit 40 by the flow of the reaction gas supply unit 30 and the carrier gas and the evaporation of the material 31.

In the above embodiment, methyltrichlorosilane (MTS), which is a liquid material, has been described as an example of a material for forming the reaction gas. However, the reaction gas may be formed using a gaseous material in addition to the liquid material. Of course.

That is, although not shown in the drawings, as an example, the silane compound, hydrogen chloride (HCl) and propane (C ₃ H ₈ ) in the chamber of the deposition unit may be supplied to the deposition unit through a direct supply line.

The deposition unit 40 is connected to the second supply line 22. The deposition unit 40 receives the reaction gas from the reaction gas supply unit 30 through the second supply line 22.

The deposition unit 40 accommodates a wafer W to form an epitaxial layer. The deposition unit 40 forms the epitaxial layer using the reaction gas. That is, the deposition unit 40 forms a thin film on the wafer W using the reaction gas.

2 to 5, the deposition unit 40 includes the chamber 100, the susceptor 200, the source gas line 300, the wafer holder 400, the first heating member 500, and the second. Heating element 600.

The chamber 100 may have a cylindrical tube shape. Alternatively, the chamber 100 may have a rectangular box shape. The chamber 100 may accommodate the susceptor 200, the source gas line 300, and the wafer holder 400. In addition, although not shown in the drawings, one side of the chamber 100 may be further provided with a gas supply for introducing a precursor and the gas discharge for discharging the gas.

In addition, both ends of the chamber 100 are hermetically sealed, and the chamber 100 may prevent external gas inflow and maintain a degree of vacuum. The chamber 100 may include quartz having high mechanical strength and excellent chemical durability. In addition, the chamber 100 has improved heat resistance.

In addition, a heat insulating part may be further provided in the chamber 100. The heat insulating part may perform a function of preserving heat in the chamber 100. Examples of the material used as the heat insulating part include nitride ceramics, carbide ceramics or graphite.

In addition, a second heating member 600 may be provided outside the chamber 100. Preferably, the second heating member 600 may be an induction coil. The induction coil is disposed outside the chamber 100. In more detail, the induction coil may surround the outer circumferential surface of the chamber 100. The induction coil may induce heat generation of the susceptor 200 and the source gas line 300 through electromagnetic induction. The induction coil may wind an outer circumferential surface of the chamber 100. The second heating member may be heated to a temperature of about 1500 ° C. or more. Preferably, the second heating member may be heated to a temperature of 1500 ℃ to 1700 ℃.

The susceptor 200 is disposed in the chamber 100. The susceptor 200 accommodates the wafer holder 400. In addition, the susceptor 200 accommodates a substrate such as the wafer (W). In addition, the reaction gas is introduced into the susceptor 200 through the second supply line 22 and the source gas line 300 from the reaction gas supply unit.

As illustrated in FIGS. 2 to 5, the susceptor 200 may include a susceptor upper plate 210, a susceptor lower plate 220, and susceptor side plates 230 and 240. In addition, the susceptor upper plate 210 and the susceptor lower plate 220 are located facing each other.

The susceptor 200 may be manufactured by placing the susceptor upper plate 210 and the susceptor lower plate 220 and placing the susceptor side plates 230 and 240 on both sides thereof.

However, since the embodiment is not limited thereto, a space for the gas passage may be made in the susceptor 200 of the rectangular parallelepiped.

The wafer holder 400 may be further disposed on the susceptor lower plate 220. In the space between the susceptor upper plate 210 and the susceptor lower plate 220, a deposition process may be performed while airflow flows. The susceptor side plates 230 and 240 serve to prevent the reaction gas from escaping when air flows inside the susceptor 200.

The susceptor 200 may include graphite having high heat resistance and easy processing to withstand conditions such as high temperature. In addition, the susceptor 200 may have a structure in which silicon carbide is coated on the graphite body. In addition, the susceptor 200 may be induction heated by itself.

The reaction gas supplied to the susceptor 200 may be decomposed into radicals by heat, and in this state, may be deposited on the wafer W or the like. For example, MTS may be decomposed into radicals containing silicon or carbon, and a silicon carbide epitaxial layer may be grown on the wafer (W). In more detail, the radical may be CH ₃ ·, CH ₄ , SiCl ₃ · or SiCl ₂ ·.

As shown in FIGS. 2-5, the source gas line 300 is disposed in the chamber 100. The source gas line 300 is connected directly or indirectly to the second supply line 22.

The source gas line 300 may have a square tube shape. Examples of the material used for the source gas line 300 include quartz and the like.

The first heating member 500 and the second heating member 600 may be provided outside the source gas line 300. That is, the first heating member 500 may directly surround the outside of the source gas line 300, and the second heating member 200 may be disposed outside the chamber 100 positioned outside the source gas line 300. ) Can be indirectly wrapped. In addition, the first heating member 500 may surround the source gas line 300 by placing a step in a portion where the source gas line 300 flows into the susceptor 200.

The first heating member 500 may be a resistive heating element that generates heat when power is applied. That is, in order to arrange the resistive heating element in a predetermined form, it may have a wire form. In one example, the heating element may include a filament, a coil or a carbon wire. Alternatively, the first heating member 500 may surround the source gas line 300 at regular intervals.

The second heating member 600 is located outside the chamber 100 and may include an induction coil. Preferably, the induction coil may surround the outer circumferential surface of the chamber 100. The induction coil may induce heat generation of the source gas line 300 through electromagnetic induction. The induction coil may wind an outer circumferential surface of the chamber 100.

The first heating member 500 and the second heating member 600 may preheat the temperature of the reaction gas or the carrier gas flowing through the source gas line 300 to a predetermined temperature or more. That is, the first heating member 500 and the second heating member 600 may heat the reaction gas or the carrier gas flowing through the source gas line to a temperature of 1300 ° C. or more. Preferably, it can be heated to a temperature of 1300 ℃ to 1500 ℃.

The first heating member 500 may include a nonmetallic material including silicon carbide (SiC) or graphite (C). Since the silicon carbide or graphite does not act as an impurity in the chamber, it is possible to produce a higher purity epi wafer compared to other materials.

As shown in FIGS. 4 and 5, the first heating member 500 may be positioned near the source gas line 300 flowing into the susceptor 200. That is, the first heating member 500 may be positioned in the direction of the source gas line 300 outside the susceptor 200, starting from the point where the source gas line 300 is inserted into the susceptor 200. Can be.

The first heating member 500 wraps the source gas line 300 in the form of a wire or has a shape of a housing to accommodate a portion of the source gas line 300. 300 can be wrapped. That is, as shown in FIG. 4, the first heating member 510 may be configured as a housing for accommodating the source gas line 300 to accommodate the source gas line 300. Alternatively, the first heating member 520 may have a wire shape to directly wrap the source gas line.

The first heating member 500 and the second heating member 600 may be partially overlapped with each other.

The reaction gas or carrier gas flowing through the source gas line 300 heated by the first heating member 500 and the second heating member 600 may be heated to a temperature of 1300 ° C to 1500 ° C. Accordingly, a portion of the reaction gas flowing through the source gas line 300 may be ionized, where the non-ionized reaction gas may be introduced into the susceptor and ionized by the second heating member 600.

That is, the reaction gas is first ionized in the source gas line 300 located outside the susceptor 200, where the reaction gas that is not ionized is received in the susceptor 200. It can be ionized secondary in gas line 300.

Accordingly, the source gas is decomposed into radicals and injected into the wafer W by the source gas line 300. By the radicals injected onto the wafer W, a silicon carbide epitaxial layer is formed on the wafer W.

As described above, the silicon carbide epitaxial growth apparatus according to the embodiment forms a thin film, such as the epitaxial layer, on a substrate such as the wafer (W). That is, the silicon carbide epitaxial growth apparatus according to the embodiment may be a deposition apparatus.

In the related art, since the reaction gas flowing through the source gas line is heated only in the portion of the source gas line introduced into the susceptor and pyrolysis occurs, the amount of the reaction gas passing through the ion gas without ionization is large, thus making it difficult to efficiently grow epi. There was this.

However, the deposition apparatus according to the embodiment first ionizes the reaction gas in the source gas line 300 located outside the susceptor and flows into the susceptor, thereby increasing the ionized reaction gas introduced into the susceptor. You can. Accordingly, since the amount of unreacted and discharged reaction gas is reduced, efficient epi wafer growth is possible, and a high quality silicon carbide epi wafer can be manufactured.

The wafer holder 400 is disposed in the susceptor 200. In more detail, the wafer holder 400 may be disposed at the rear of the susceptor 200 based on the direction in which the source gas flows. The wafer holder 400 supports the wafer (W). Examples of the material used for the wafer holder 400 include silicon carbide or graphite.

Hereinafter, a deposition method according to an embodiment will be described with reference to FIG. 6. For the purpose of clarity and simplicity, detailed description of parts identical or similar to those described above will be omitted.

Referring to FIG. 6, the deposition method according to the embodiment may include preheating the reaction gas (ST10), heating the reaction gas (ST20), and reacting (ST30).

In the step of preheating the reaction gas (ST10), the reaction flowing through the source gas line by the first heating member 500 directly surrounding the source gas line 300 and the second heating member 600 directly indirectly wrapping the reaction gas The gas or carrier gas may be preheated above a certain temperature.

That is, the first heating member 500 includes a resistive heating element that generates heat when power is applied, and the second heating member 600 includes an induction coil for induction heating through electromagnetic induction. The reaction gas or the carrier gas may be heated to a temperature of about 1300 ° C. or more by the first heating member 500 and the second heating member 600 disposed at regular intervals. Preferably it may be heated to a temperature of 1300 ℃ to 1500 ℃. Accordingly, the reaction gas may be primarily ionized to decompose into radicals.

Subsequently, in the step ST20 of heating the reaction gas, the reaction gas may be introduced into the susceptor, and heated by the second heating member 600 to be decomposed into radicals. That is, unreacted gases that are not ionized in the source gas line 300 outside the susceptor 200 may be heated by the second heating member 600 to be decomposed into radicals. The second heating member 600 may include an induction coil, and the induction coil may induce heat generation of the susceptor 200 by surrounding the outer circumferential surface of the chamber 100. The second heating member may be heated to a temperature of about 1500 ° C. or more. Preferably, the second heating member may be heated to a temperature of 1500 ℃ to 1700 ℃.

Subsequently, in the reacting step ST30, reaction radicals decomposed into radicals may be injected onto the wafer and react to form a silicon carbide epitaxial layer on the wafer (W).

Conventionally, since the reaction gas or carrier gases are supplied at room temperature, and ionization of the reaction gas occurs at a limited heating portion near the susceptor, the amount of reaction gas is less ionized and there is a problem that an undecomposed reaction gas increases. . Accordingly, there is a problem in that the efficiency of epi growth is lowered.

On the other hand, the deposition method according to the embodiment may be ionized primarily before the reaction gas is introduced into the susceptor by the first heating member 500 and the second heating member.

Accordingly, the deposition method according to the embodiment can reduce the amount of unreacted gas, thereby increasing the efficiency of the silicon carbide epitaxial wafer process, and enables the production of high quality silicon carbide epitaxial wafers.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. In addition, the features, structures, effects, and the like illustrated in the embodiments 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 clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims (9)

chamber;
A susceptor accommodated in the chamber to receive a substrate;
A source gas line connected to the susceptor and introducing a source gas into the susceptor to form a thin film on the substrate;
A first heating member for heating the source gas line; And
And a second heating member for heating the source gas line and the susceptor. The method of claim 1,
The susceptor comprises silicon carbide (SiC) or graphite (C),
And the first heating member comprises silicon carbide (SiC) or graphite (C). The method of claim 1,
And the first heating member is located inside a susceptor and surrounds an outer surface of the source gas line. The method of claim 1,
And a temperature of the source gas line heated by the first heating member and the second heating member is 1300 ° C to 1500 ° C. The method of claim 1,
The chamber includes a second heating member surrounding the outer circumferential surface of the chamber,
And the second heating member positioned outside the first heating member and the susceptor overlap each other. The method of claim 1,
A source gas supply unit supplying the source gas to the source gas line,
And the source gas supply portion contains a compound of silicon and carbon. Heating the reaction gas inside the source gas line;
Heating the reaction gas inside a susceptor; And
And reacting the reactant gas with a substrate. 8. The method of claim 7,
The heating of the reaction gas inside the source gas line may be performed by a first heating member including silicon carbide (SiC) or graphite (C) and a second heating member including an induction coil,
And heating the reaction gas inside the susceptor is heated by a second heating member comprising an induction coil. 8. The method of claim 7,
The heating of the reaction gas inside the source gas line may include heating the reaction gas at a temperature of 1300 ° C to 1500 ° C.

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