KR101922469B1 - Chemical vapor deposition low resistance silicon carbide bulk manufacturign apparatus - Google Patents

Abstract

In the present invention, a gas mixing system for supplying a gas to a CVD furnace in which a chemical vapor deposition low-resistance silicon carbide bulk is produced is composed of a header 10 and a spraying line 20, Is supplied with the MTS, nitrogen, and hydrogen through the supply pipe to the gas mixing system, and the MTS, nitrogen, and hydrogen are supplied to the gas mixing system through the supply pipe At least two nozzles 32 are connected to the header 10 and MTS and nitrogen and hydrogen are injected into the deposition path 40 from the nozzles 32 and the injection lines (N2) gas used in a known manufacturing method through the improvement of the gas mixing system because a small number of small holes are provided in the injection line. Low-resistivity CVD SiC can be produced at the input, and In addition to the small gas to be uniformly injected, the silicon carbide manufacturing device that can reduce the variation in the nozzle-specific resistance value is provided.

Description

Technical Field [0001] The present invention relates to a chemical vapor deposition low-resistance silicon carbide bulk manufacturing apparatus,

[0001] The present invention relates to a chemical vapor deposition (CVD) low resistance silicon carbide bulk manufacturing apparatus and, in a manufacturing process for manufacturing low resistance SiC (silicon carbide) by chemical vapor deposition (CVD) To an apparatus for fabricating low-resistance silicon carbide which optimizes the nitrogen concentration used and also has an optimum nitrogen concentration in SiC according to the respective resistance value.

Generally, silicon carbide is used for silicon carbide parts used in semiconductors and LED processes, wafer carriers called a susceptor, boats for deposition processes, tubes, etch processes, etc. It is used as ring, shower plate and so on.

Particularly, due to the tremendous growth of the semiconductor industry, component suppliers used in the manufacture of silicon integrated circuits (ICs) had to improve their products to increase IC productivity without increasing costs. One example of the need for such an improvement is to increase the wear life of capillary or weld tip guides used in wire ball bonding operations in IC fabrication processes and to improve the performance of various devices made of silicon carbide.

On the other hand, an attempt to lower the resistivity of a CVD-SiC compact and apply it as a heater has been known before. For example, nitrogen gas is introduced at a flow rate of 0.4 L / min in a methyltrichlorosilane (MTS) , A SiC (N) layer of a SiC (N) / TiN / SiC structure was grown to a thickness of 0.44 mu m at a deposition temperature of 1400 DEG C and a pressure of 1 atm, a hydrogen gas flow rate of 2.0 L / It is difficult to freely control the ratio of the MTS concentration as the raw material and the nitrogen gas concentration, so that pores are easily generated inside, and therefore, It is difficult to obtain gas-impermeable CVD-SiC.

As a method of obtaining a nitrogen-doped CVD-SiC compact by controlling the amount of nitrogen gas introduced together with the source gas, a silicon monocrystalline substrate is heated to 900 to 1,200 DEG C, and monosilane (SiH4) gas, propane gas, After a very thin SiC film is formed on the substrate using hydrogen gas as a gas, the temperature of the substrate is then raised to 1300 to 1400 DEG C, and a nitrogen gas (1 x ~1 10 ^-2 cc / min, the concentration of the nitrogen gas with respect to the raw material ^{gas, 1 × 10 -2 ~1 (cc} / min) /0.05~0.3 (cc / minute) = 0.01 / 0.1 to 1 / 0.6 = 10 To 167 vol.%), To grow an n-type 3C type SiC single crystal thin film on a substrate, and to obtain a thin film of 0.5 to 3 mu m by growing for 1 hour.

Of course, in Korean Patent Laid-Open Publication No. 10-2002-0011860, as an SiC formed body manufactured by the CVD method using nitrogen gas together with a raw material gas and a carrier gas, the concentration of the raw material gas (flow rate of raw material gas (l / (Nitrogen gas flow rate (l / min) / raw material gas flow rate (l / min)) of 10 to 120% by volume and nitrogen concentration of 5 to 15% by volume and gas flow rate A light transmittance of 1.1 to 0.05% and a resistivity of 3 x 10 < ^-3 > to 10 < ^-5 > OMEGA m, and the light transmittance of the measurement object is set to 0.5 mm , And measuring the SiC near-infrared region at 500 to 3000 nm using a spectrophotometer. &Quot;

U.S. Patent No. US4772498 (September 20, 1988) states that "a capillary having axially extending passages that terminate at relatively small diameter capillary openings through which fine electrical conductor wires pass, allowing fine electrical conductor wires to pass through Connecting said wire to an electrical component by applying pressure to said ball by means of said capillary end, said capillary being essentially of an oxygen or oxygen containing compound A silicon carbide coating obtained by chemical vapor deposition of a silicon carbide coating on a substrate in the absence of a substrate having a substantially smooth surface and having a constant velocity of at least 0.1 ohm-cm, a uniform Vickers hardness of greater than 2500 kg / mm ² , cm < ^{3 &} gt ;, at least a thermal shock resistance coefficient of 180 and a fracture toughness of 3.7 KIC (MPa / m) Silicon carbide capillary "

However, in recent years, the necessity of low-resistivity SiC production is increasingly required to supply and mix nitrogen gas at the time of SiC production. However, the above-mentioned technology has the disadvantage that it is easy to supply nitrogen gas to be present in SiC in a fixed amount Nor does it provide a technique for uniformly injecting nitrogen gas into the nozzle.

Therefore, there is an urgent need to develop a technique for manufacturing silicon carbide which can control the resistance value of SiC effectively and control the mixing and mixing of nitrogen gas, thereby reducing the deviation of the resistance value of each nozzle.

Prior Art 1: Korean Patent Publication No. 10-2002-0011860 Feb. 09, 2002) Prior Art 2: United States registered patent: US04772498 (September 20, 1988)

Chemical vapor deposition (CVD) For the production of low-resistance silicon carbide bulk, the technique of supplying and mixing nitrogen gas during SiC production is optimized, and a nitrogen gas The present inventor has developed a technique for uniformly injecting nitrogen gas into a nozzle for injecting a nitrogen gas into the cavity, and also to provide a device for manufacturing a silicon carbide bulk which can reduce a variation in resistance value of each nozzle.

The above-described object of the present invention is to provide a semiconductor device having a nitrogen concentration value at a depth of 1,500 nm or more from the bulk surface of the metastable layer when the resistance value of the chemical vapor deposition low resistance silicon carbide bulk is 0.3 Ω or less is 4.0 × 10 ¹⁸ atoms / cm ³ , And the nitrogen concentration value at a depth of 1,500 nm or more from the bulk surface as a metastable layer when the resistance value of the chemical vapor deposition low resistance silicon carbide bulk is 0.003? Or less is 4.0 x 10 ¹⁹ atoms / cm ³ Or more of the silicon carbide bulk of the low-resistance silicon carbide bulk,
A gas mixing system line for supplying a gas to a deposition furnace in which a chemical vapor deposition low-resistance silicon carbide bulk is produced comprises a header 10 and a spraying line 20,
A main tank storing the MTS, a buffer tank having a function of supplying a predetermined amount of MTS, a supply tank supplying the MTS to the evaporator, and an evaporator evaporating the MTS,
The MTS is transferred from the main tank to a buffer tank. At this time, hydrogen (H2) gas and nitrogen (N2)
The MTS present in the buffer tank is transferred to a service tank where hydrogen gas is supplied together,
The header 10 and the jetting line 20 are in the shape of a line and the header 10 is an outer tube surrounding the jetting line 20. The header 10 and the header 10), and the space
Nitrogen is supplied to the inlet side of the jetting line 20 existing in the header 10 and a plurality of small holes are provided in the entire jetting line 20. The nitrogen supplied from the inlet side of the jetting line 20 Out through the small holes to the space between the outside of the injection line 20 and the inside of the header 10,
The supply pipe is connected to a space between the outside of the jetting line 20 and the inside of the header 10 in front of the header 10, , The supply pipe (31) is connected to the header (10) in a vertical direction,
The nozzle 32 is connected to the injection line 20 when the nozzle 32 is connected to the header 10, and furthermore, at least two nozzles 32 for spraying MTS, nitrogen and hydrogen into the deposition furnace, Is connected to the space between the outside of the header (10) and the inside of the header (10), and the nozzle (32) and the header (10) are connected in the vertical direction. By the chemical vapor deposition low resistance silicon carbide bulk manufacturing apparatus It is achievable.

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In the present invention, in order to produce a low-resistance silicon carbide bulk, a mixed gas of MTS, nitrogen and hydrogen is supplied to the evaporator through a gas mixing system improvement, (N ₂₎ it can be a low resistance CVD SiC produced very little nitrogen (N ₂₎ gas than the gas in input, and also producing silicon carbide, which as well as to uniformly injecting nitrogen gas, can reduce the deviation of the nozzle by the resistance Device can be provided

1 is a view showing an embodiment showing a process of mixing MTS transport and used gas in the present invention.
Figure 2 is an illustration of an embodiment showing a gas mixer system line.
Figure 3 is a simplified view of the reactor and the dust collector.
Figures 4 and 5 are views of embodiments showing the nitrogen concentration in the low resistance SiC.
6 is a graph showing the concentration of SiC nitrogen having a general resistance.

Hereinafter, a chemical vapor deposition (CVD) low-resistance silicon carbide bulk according to an embodiment of the present invention and a manufacturing method thereof will be described in detail.

The detailed description of common techniques necessary for explaining the present invention can be omitted.

Generally, in a silicon carbide production operation by a chemical vapor deposition method, a silicon carbide precursor gas such as a mixture of methyltrichlorosilane (MTS, Methyltrichlorosilane), hydrogen and argon is supplied to a deposition chamber and reacted to produce silicon carbide The gas is heated to a temperature. Silicon carbide is deposited as a film or shell on a solid mandrel installed in a deposition chamber. After the desired thickness of silicon carbide is deposited on the mandrel, the coated mandrel is removed from the deposition chamber and the deposition is separated from the mandrel. Monolithic silicon carbide plates and cylinders have been produced by applying such chemical vapor deposition (CVD) techniques using substrates or mandrel shapes of suitable shapes.

Accordingly, the present invention proposes a method of producing silicon carbide by a chemical vapor deposition (CVD) method, and more particularly, to a method of producing a low-resistance silicon carbide by effectively supplying nitrogen gas and supplying less nitrogen gas than the prior art .

On the other hand, the physicochemical properties of the low-resistance silicon carbide produced by the above-described production method of the present invention are analyzed and utilized for semiconductor processing.

First, the conventional method will be described as follows.

Chemical vapor deposition (CVD) systems are used to produce silicon carbide products. And methyltrichlorosilane (MTS) are provided, and argon is used as the carrier gas for MTS. And, with the suspended MTS, argon is supplied under sealed conditions and then mixed with hydrogen and nitrogen (N ₂ ).

The mixed precursor gases are supplied to the deposition furnace through an injector. Then, the dissociation of the MTS and the silicon carbide deposit is caused, and the exhaust gas generated in the dissociation reaction is discharged.

On the other hand, silicon carbide precursors are selected from materials that can react to form silicon carbide. These materials generally comprise a component capable of reacting to form a silicon moiety such as silane or chlorosilane and a component capable of reacting to form a carbon moiety such as a hydrocarbon. Hydrocarbon substituted silanes are preferred silicon carbide precursors because the silanes contain silicon and carbon moieties within a single compound.

In addition, inert, non-reactive gases such as argon, helium or other inert gases may be used as carriers for normal liquids (e.g., liquids in conventional STP) precursors. Methyltrichlorosilane (MTS) is the preferred precursor when used with hydrogen (H ₂ ) to remove chlorine released, especially when MTS is dissociated. For MTS (liquid at room temperature), argon is generally used as an inert, non-reactive carrier gas. At this time, argon acts as a diluent.

1 is a view showing an embodiment showing a process of mixing MTS transport and used gas in the present invention.

The process steps are as follows: The following procedure is the initial step of mixing the gas at all stages of the deposition process,

1) The MTS is transferred from the main tank where MTS (methyltrichlorosilane) is stored to the buffer tank. At this time, hydrogen (H ₂ ) gas and nitrogen (N ₂ ) gas are also supplied.

For reference, the buffer tank has a function of supplying a predetermined amount, and a device for supplying a predetermined amount is added to the buffer tank.

2) The MTS present in the buffer tank is transferred to the service tank. At this time, hydrogen (H ₂ ) gas is supplied together. The supply tank is a tank that carries the transfer function to supply the MTS directly to the vaporizer,

3) The MTS is supplied to the vaporizer in the service tank, the MTS is vaporized in the evaporator, and the vaporized MTS is supplied to the gas mixer system line together with nitrogen and hydrogen gas. At this time, hydrogen is continuously supplied to the evaporator.

In this process, all the processes are controlled at the set temperature. As a result, a constant supply of MTS is possible and uniform mixing of hydrogen and nitrogen is induced,

That is, as a method of supplying MTS to a conventional evaporator, a one-stage mixing system is used in which an MTS located in a thermostatic chamber is supplied through a line and argon, nitrogen, and hydrogen are directly supplied to the MTS supply line. However, in the present invention, a buffer tank and a service tank are disposed in the middle of the MTS furnace to the evaporator, and then passed through a vaporizer.

2 is a view of an embodiment showing a gas mixer system line injected into an evaporation furnace.

The gas mixing system of the present invention comprises a header (10) and a spray line (20).

The header 10 is an outer tube wrapping the injection line 20 and the diameter of the header 10 used in the present invention is 80 mm and the diameter of the injection line 20 existing in the header used in the present invention Is 10 mm. Header was sanitary fastened (30) using sanitary parts, and it was made to withstand the pressure and to have high sealing effect.

Nitrogen and hydrogen supplied from an evaporator are supplied through a supply pipe 31 to the inlet side of the header 10 and the diameter of the supply pipe 31 used in the present invention is 25 mm. Is connected to the front side of the header 10,

At least two nozzles (32) are connected to the header (10). Of course, as shown in the drawings, in the present invention, four nozzles 32 are used as one embodiment. MTS, nitrogen, and hydrogen are injected into the deposition furnace 40 from the respective nozzles 32. [ The diameter of the nozzle 32 used in the present invention is 25 mm,

As shown in the drawing, nitrogen is supplied to the inlet of the jetting line 20 existing in the header 10, and a plurality of 1 mm holes are provided in the jetting line.

In addition, the values of the diameters of the headers, the lines, and the nozzles shown in the above embodiment are only examples, and the features of the present invention are not necessarily limited to the diameters.

Figure 3 is a simplified view of the reactor and the dust collector.

In Fig. 3, the reactor means a deposition furnace 40 in which a CVD process is performed. That is, SiC is deposited by the mixed gas injected from the injection line 20,

The exhaust gas generated in the dissociation reaction after the deposition is discharged through the exhaust port (the portion connected to the dust collector 50 at the lower end of the deposition path 40 in the figure) And,

The deposition furnace 40 is a housing made of a water-cooled stainless steel, and a graphite mandrel, a graphite heating member and a graphite insulating tube are provided in the housing. And the mixed precursor gases introduced into the deposition furnace 40 cause dissociation of the MTS and silicon carbide deposits on the inner surface of the mandrel as it passes over the inner surface of the heated graphite mandrel.

The exhaust gases discharged from the exhaust port of the deposition furnace 40 are removed from the solid materials floating through the filter, though not separately shown in the figure, and then passed through a vacuum pump controlling the reduced pressure in the deposition furnace Also. The exhaust gases then pass through a scrubber 50, which recovers the necessary gases, and is then discharged to the atmosphere.

- Dopant feed rate -

The present invention relates to a chemical vapor deposition (CVD) low-resistance silicon carbide bulk and a method of manufacturing the same. By improving the gas mixing system, low-resistivity SiC can be manufactured even when N 2 is supplied less than the conventional method.

Tables 1 to 2 show the content of each component in the gas supplied to the vapor deposition furnace 40. Table 1 is the component content in our method and Table 2 is the component content in the prior art,

Comparing Tables 1 and 2, it can be seen that the present invention contains 0.65% or 0.65% nitrogen content in the feed gas at 0.00062 to produce low resistance SiC (standards include MTS and hydrogen EO was defined as 100% of the sum of

However, conventionally, a nitrogen content of 10 to 60% must be included in order to produce low resistance low resistance SiC. (The standard is when the sum of MTS and hydrogen is set at 100%),

As a result, in the present invention, the ratio of nitrogen gas can be greatly reduced.

Table 1. (SLPM: Standard liter per minute)

Table 2, (SLPM: Standard liter per minute)

Figures 4 and 5 are views of embodiments showing nitrogen concentration in a chemical vapor deposition (CVD) low resistance silicon carbide bulk.

The concentration of nitrogen in the low-resistivity silicon carbide bulk surface at depths greater than 1,500 nm (metastable layer) was measured and analyzed using scanning ion mass spectroscopy. In addition, for trace element impurities, gas discharge mass spectroscopy (GDMS) may be used to analyze the specimens.

FIG. 4 is a graph showing the measured values of nitrogen concentration in low-resistance SiC of 0.3 Ω or less. As shown in FIG. 4, when the depth of nitrogen exceeding 4.0 × 10 ¹⁸ atoms / cm ³ in a depth of 1,500 nm or more (metastable layer) , And it can be seen that the nitrogen concentration value is smaller than 1.0 x 10 ¹⁹ atoms / cm ^{3, which} is the nitrogen concentration value proposed in the prior art.

5 is a graph showing the measured value of the nitrogen concentration in a low resistance silicon carbide bulk having a value of 0.003? Or less, which is a new low resistance used in recent years, and a depth ) Is a value representing the nitrogen concentration at 1,500 nm or more (metastable layer), and has a nitrogen concentration of 4.0 x 10 ¹⁹ atoms / cm ³ or more.

Figure 6 is an illustration of an embodiment showing the nitrogen concentration in a silicon carbide bulk with a general resistance made by a chemical vapor deposition (CVD) method.

That is, FIG. 6 is a diagram showing the SiC nitrogen concentration in a general resistance having a resistance value of 1? .Cm or more, and the concentration measuring method is the same as that described in FIG. 4 and FIG.

It can be seen from the figure that the nitrogen concentration in the silicon carbide bulk surface is 1.4 x 10 ¹⁸ atoms / cm ³ or less near the depth of 1,500 nm or more (metastable layer).

- Characteristics comparison -

The characteristics of the low-resistance SiC produced in the manufacturing process of the present invention were measured and compared with the conventional products.

The characteristic values of the low-resistance SiC produced in the manufacturing process of the present invention in Table 3 are marked as D-clean @

In Table 3, it can be seen that characteristics of high strength (bending strength of 517Mpa) and high thermal conductivity (250W / mK) characteristic of general SiC material do not change while keeping trace elements below 5 ppmw.

Table 3.

As a result, it can be seen that the low-resistance SiC produced by the manufacturing method of the present invention maintains the same resistance value while satisfying the characteristic values required for the low-resistance SiC even though the nitrogen concentration is lower than the latter.

10: Header 20: Spray Line
31: supply pipe 32: nozzle
30: Sinitary fastening 40: Deposition furnace
50: a scrubber

Claims (4)

Characterized in that the nitrogen concentration value at a depth of 1,500 nm or more from the bulk surface as a metastable layer when the resistance value of the chemical vapor deposition low-resistance silicon carbide bulk is 0.3 Ω or less is 4.0 × 10 ¹⁸ atoms / cm ³ or more, Characterized in that the nitrogen concentration value at a depth of 1,500 nm or more from the bulk surface of the metastable layer when the resistance value of the chemical vapor deposition low-resistance silicon carbide bulk is not more than 0.003 Ω is not less than 4.0 × 10 ¹⁹ atoms / cm ³ A chemical vapor deposition low resistance silicon carbide bulk manufacturing apparatus for producing a resistive silicon carbide bulk,
A gas mixing system line for supplying a gas to a deposition furnace in which a chemical vapor deposition low-resistance silicon carbide bulk is produced comprises a header 10 and a spraying line 20,
A main tank storing the MTS, a buffer tank having a function of supplying a predetermined amount of MTS, a supply tank supplying the MTS to the evaporator, and an evaporator evaporating the MTS,
The MTS is transferred from the main tank to a buffer tank. At this time, hydrogen (H2) gas and nitrogen (N2)
The MTS present in the buffer tank is transferred to a service tank where hydrogen gas is supplied together,
The header 10 and the jetting line 20 are in the shape of a line and the header 10 is an outer tube surrounding the jetting line 20. The header 10 and the header 10), and the space
Nitrogen is supplied to the inlet side of the jetting line 20 existing in the header 10 and a plurality of small holes are provided in the entire jetting line 20. The nitrogen supplied from the inlet side of the jetting line 20 Out through the small holes to the space between the outside of the injection line 20 and the inside of the header 10,
The supply pipe is connected to a space between the outside of the jetting line 20 and the inside of the header 10 in front of the header 10, , The supply pipe (31) is connected to the header (10) in a vertical direction,
The nozzle 32 is connected to the injection line 20 when the nozzle 32 is connected to the header 10, and furthermore, at least two nozzles 32 for spraying MTS, nitrogen and hydrogen into the deposition furnace, Is connected to a space between the outside of the header (10) and the inside of the header (10), and the nozzle (32) and the header (10) are connected in a vertical direction.
The method according to claim 1,
Wherein the resistance of the low-resistance silicon carbide bulk is 0.03? Or less and the trace element is 5 ppmw or less. delete delete

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