Solid silicon carbide manufacturing process

Abstract

The invention relates to the field of solid silicon carbide manufacturing, in particular to a solid silicon carbide manufacturing process which comprises a large reactor, an air nozzle, a cavity, an exhaust pipeline, a vacuum pump, primary tail gas equipment, secondary tail gas equipment and a neutralized water treatment system. According to the present invention, the 60-degree and 120-degree flow dividing nozzles are installed, such that the deposition of the base material is uniform, and the temperature influence of the Si gas type is reduced in the multi-pipe nozzle form so as to solve the Si-related parasitic reaction generating the adverse effect on the SiC deposition, and the particle formation and the nozzle blocking caused by the Si-related parasitic reaction; high-temperature unreacted substances, gas and hydrogen gas discharged in the SiC-CVD deposition process can be discharged at the concentration lower than the safety standard after being fully combusted by the electric heater, and in addition, MTS unreacted substances, hydrogen chloride (HCl) and other tail gas generated in the SiC-CVD deposition process can also be simultaneously treated by a neutralizing water treatment system lower than the safety standard.

Description

Technical Field

[0001] The present invention relates to the field of solid silicon carbide manufacturing, and particularly to a solid silicon carbide manufacturing process. Background Art

[0002] With the high integration and line width refinement of semiconductor engineering, high-power plasmas are required. Therefore, components related to the dry etching process also need components with excellent plasma resistance and increased lifespan. As a result, materials that can replace silicon, quartz, and alumina commonly used in existing semiconductor processes are needed. As a substitute material, the proportion of parts made of SiC (Silicon carbide) material has been increasing rapidly. Chemical vapor deposition (CVD), which is used to manufacture dry etching equipment using the above-mentioned plasma and components used in semiconductor processes, is a technology that causes gaseous compounds to react on the surface of a heated substrate and deposits the products on the substrate surface. CVD is currently the most commonly used thin-film manufacturing technology in the commercial field. The characteristics of the CVD (chemical vapor deposition) process are that materials that are difficult to manufacture due to their high melting points can be easily manufactured at temperatures below the melting point, the deposited thin film has high purity, can be mass-produced, the cost is lower than that of the PVD process, and various elements and compounds can be deposited.

[0003] In the traditional technology for manufacturing SiC semiconductor components using this CVD process, in order to improve process efficiency and uniform deposition, multiple injection inlets are arranged in the cavity and used simultaneously. In this way, multiple raw material gas injection inlets are used simultaneously in the cavity to manufacture components for SiC semiconductors, where SiC is deposited on the substrate and finally grows into a single SiC polycrystalline layer. The substrate is fixed inside the vacuum cavity. After creating an appropriate working environment such as low pressure, normal pressure, or plasma inside the cavity, the reaction gas is injected into the cavity, and the particles constituting the reaction gas are deposited on the substrate. The by-products generated after deposition are discharged to the outside through the exhaust pipeline using a vacuum pump connected to the exhaust pipeline.

[0004] In the traditional method, such as Figure 5 The shape of the nozzle for supplying the raw material gas is parallel in one direction. The supply ratio of the nozzle gas is controlled to concentrate the process gas on the product and ensure uniform deposition of the film layer. However, when supplying the raw material gas, since the temperature of the gas injection port part is lower than that of the graphite substrate part, natural convection caused by the temperature difference from the substrate surface upwards forms a vortex of gas at the edge part. The formation of the vortex will extend the residence time of the reaction gas, resulting in the uniform nucleation and growth of the chemical paper participating in the deposition reaction before reaching the substrate, thus having an adverse effect on the monomer of the total film thickness.

[0005] As described above, the method of depositing SiC by CVD can be simply manufactured by bubbling hydrogen gas into a liquid raw material with a silicon-to-carbon ratio of 1:1 (e.g., MTS:CH3SiCl3). However, during thermal decomposition, the reaction occurs rapidly near the gas inlet, making it difficult to regulate the reaction to occur uniformly throughout the reactor. Moreover, in the case of a reactor for mass production, most have a diameter of over 1 meter and a height of over 2 - 3 meters. Therefore, major problems such as thickness deviation occur depending on the position of the sample. When operating in this way, in a liquid raw material with a silicon-to-carbon ratio of 1:1, such as MTS (methyltrichlorosilane: CH3SiCl3), multiple nozzles for supplying and thermally decomposing by bubbling hydrogen gas form parasitic reactants before reaching the substrate, resulting in changes in the proportion of reaction gas species and the formation of particles, leading to nozzle blockage and non-uniform deposition after the process.

[0006] The traditional method is for large-area coating conditions. By changing the reaction temperature, raw material flow rate, reaction pressure, rotation speed, and the number of nozzles, the coating thickness is ensured. However, to improve the deposition efficiency, the loading positions of the product substrates to be considered are the same. When operating in this way, the previous substrate loading method analyzes the thermal distribution state and the interference effect of the internal structure of the substrate loading, causing the reaction gas to adsorb onto each substrate, minimizing the thickness deviation of the polycrystalline SiC layer deposited on the substrate to improve the processing efficiency.

[0007] Conventional such as Figure 4 , a vacuum pump is installed on one side of the exhaust pipeline connected to the chamber to generate a constant vacuum pressure, and a primary exhaust gas device and a secondary exhaust gas device are installed to purify the discharged process gas in sequence and then discharge it into the atmosphere. When growing SiC crystals using the CVD method, the washing of the chlorine-containing gas wastewater reacts with the chemical substances extracting chlorine in the chlorine gas stream. To prevent chlorine from being discharged into the atmosphere, a sodium hydroxide (NaOH) solvent is generally used for chlorine absorption. The effluent is collected and removed from these chlorine scrubbers through reaction, adsorption, or absorption to prevent chlorine from leaking into the atmosphere. This traditional technology has the trouble of performing periodic cleaning to handle the by-products accumulated in the exhaust line, and some components need to be removed during each periodic cleaning, so there is a problem that the operation process of the work stops. Additionally, due to the stop of the working process, not only does the productivity decrease, but also a large amount of facility maintenance costs are generated.

[0008] Aiming at the problems that the above traditional method for manufacturing solid silicon carbide has thickness deviation caused by changes in the flow direction of the reaction gas required to form a uniform film on large-sized coatings and substrates in a large chamber, and at the same time, the operation of handling the by-products accumulated in the exhaust line is troublesome and the maintenance cost is high, a manufacturing process for solid silicon carbide can be designed. Summary of the Invention

[0009] In order to overcome the problems that in the traditional method of manufacturing solid silicon carbide, thickness deviation occurs due to the flow change of the reaction gas required to form a uniform film on the large-size coating and the substrate in the large cavity, and at the same time, the operation of dealing with the by-products accumulated in the exhaust line is troublesome and the maintenance cost is high.

[0010] The technical solution of the present invention is as follows: a solid silicon carbide manufacturing process, including a large reactor, jet nozzles, a cavity, an exhaust pipeline, a vacuum pump, a primary tail gas device, a secondary tail gas device, a neutralization water treatment system, and an electric heater; jet nozzles for introducing reaction gas into the reactor are uniformly distributed vertically on the outer side of the large reactor; a cavity is provided inside the large reactor; one end of the exhaust pipeline of the cavity is equipped with a vacuum pump; a primary tail gas device and a secondary tail gas device are successively installed at the exhaust end of the vacuum pump; an electric heater is arranged inside the exhaust pipeline; a neutralization water treatment system is connected in series at the lower end of the electric heater.

[0011] Among them, the shape of the jet nozzles consists of parallel injection, a split nozzle installed at 60° up and down, and a split nozzle installed at 120°.

[0012] Preferably, first, the nozzles of the jet nozzles of the cavity are improved. The shape of the nozzles can consist of parallel injection, a split nozzle installed at 60° up and down, and a split nozzle installed at 120°. There is no significant difference in the overall concentration distribution in terms of appearance, and it has the effect of reducing the concentration difference between the two gases between the platforms through the split nozzles at the front end. In fact, if the argon mole fraction at a certain distance from the center of the reactor is confirmed on the platform along the z-axis, it can be confirmed that at the average concentration between the platforms, compared with the case without split nozzles, the gas concentration difference between the upper and lower platforms has a tendency to decrease when there are nozzles. In particular, when the 120° nozzle is installed, it is confirmed that the mole fraction difference of argon between the stages is the smallest, and it is characterized by this.

[0013] Then, by directly coating the spraying gas for the loading position on each substrate, it has the effect of improving the deposition uniformity, and a relatively uniform deposition efficiency can be obtained;

[0014] Finally, the hydrogen gas discharged in the SiC-CVD deposition process can be discharged at a concentration lower than the safety standard after being fully combusted by an electric heater. In addition, other tail gases such as unreacted MTS and hydrogen chloride (HCl) generated in the SiC-CVD deposition process can also be subjected to a neutralization water treatment system at a concentration lower than the safety standard. For the above treatment, unreacted substances and gases after the collection process can be collected and effectively managed. The high-temperature unreacted substances and gases are cooled by a water-cooled jacket. After the gas is first collected by a cold trap, two or more particle filters are connected in series to collect particles more effectively and minimize the damage to the dry pump, including a throttle valve, so as to maintain and adjust a certain process pressure during the SiC-CVD process. In addition, in order to effectively replace the cold trap and the filter, manual valves are installed at the front and rear ends, which can solve the problem of oxidation of the exhaust pipeline caused by residual unreacted substances and gases.

[0015] Preferably, the jet orifice uses a diverter nozzle installed at 60° and 120° to make the deposition on the substrate uniform.

[0016] Preferably, the effect of reducing the concentration difference between the two gases between the stages is achieved through the diverter nozzle at the front end. In fact, when the argon mole fraction at a position at a certain interval from the center of the reactor is confirmed along the z-axis on the stage, it can be confirmed that at the average concentration between the stages, compared with the case without a diverter nozzle, the gas concentration difference between the upper and lower stages has a tendency to decrease when there is a nozzle.

[0017] Preferably, especially when a 120° nozzle is installed, the mole fraction difference of argon between the stages is confirmed to be the smallest.

[0018] Preferably, the neutralization water treatment system includes a pressure control valve, a water-cooled jacket, a throttle valve, and a particle filter; the pressure control valve is located at the very front end of the treatment process; the water-cooled jacket is immediately behind the pressure control valve; a throttle valve is installed at the output end of the water-cooled jacket; the particle filter is located after the throttle valve; the particle filter is the last component of the entire treatment process.

[0019] Preferably, the method for positioning the manufacture of solid silicon carbide: By directly coating the spraying gas for the loading position on each substrate, it has the effect of improving the deposition uniformity.

[0020] The beneficial effects of the present invention:

[0021] Compared with the traditional physical silicon carbide manufacturing process and the method for treating the appendages of the physical silicon carbide deposition process, in the present invention, by installing 60° and 120° shunt nozzles as compared with the case of injecting parallel to the shape of the nozzle, the deposition on the substrate is made uniform, and the temperature influence of the Si gas types is reduced in the form of a multi-tube nozzle, thereby solving the Si-related parasitic reactions that have an adverse effect on SiC deposition, as well as the resulting particle formation and nozzle blockage;

[0022] In the present invention, the nozzle form for supplying MTS / is in the form of a multi-tube nozzle of two or three types and a cooling line, and no reaction occurs in the nozzle, and a reaction gas with a uniform composition is supplied;

[0023] At the same time, in order to improve the efficiency of the coating thickness and deposition uniformity for large-area coating and coating of a large number of substrates, due to different loading positions and vertical intersection, the deposition uniformity at the front end and up and down of the substrate is improved, the thermal distribution state of the conventional substrate loading method and the internal structure interference effect caused by substrate loading are analyzed, the reaction gas is adsorbed onto each substrate, and the thickness deviation of the SiC polycrystalline layer deposited on the substrate is minimized to improve the processing efficiency;

[0024] In the SiC-CVD deposition process, the high-temperature unreacted substances, gases, and hydrogen gas discharged can be fully combusted and treated by an electric heater and then discharged at a concentration lower than the safety standard. In addition, the unreacted substances of MTS and other tail gases such as hydrogen chloride (HCl) generated in the SiC-CVD deposition process can also be simultaneously subjected to a neutralization water treatment system lower than the safety standard. For the above treatments, the unreacted substances and gases can be collected after the process for effective management. Description of the Drawings

[0025] Figure 1 Shown is the external view of the reactor of the manufacturing process of the present invention;

[0026] Figure 2 Shown is the flow chart of the method for treating the appendages of the physical silicon carbide deposition process of the manufacturing process of the present invention;

[0027] Figure 3 Shown is the schematic diagram of the double-tube or multi-tube shunt structure of the jet orifice of the manufacturing process of the present invention;

[0028] Figure 4 Shown is the schematic diagram of the flow of the traditional physical silicon carbide process appendage treatment of the manufacturing process of the present invention;

[0029] Figure 5 Shown is the schematic diagram of the gas flow direction of the traditional nozzle of the manufacturing process of the present invention.

[0030] Description of the reference numerals in the drawings: 1. Large reactor; 2. Jet nozzle; 100. Cavity; 200. Exhaust pipeline; 300. Vacuum pump; 400. Primary tail gas equipment; 500. Secondary tail gas equipment; 6. Neutralization water treatment system; 601. Pressure control valve; 602. Water-cooled jacket; 603. Throttle valve; 604. Particle filter; 700. Electric heater. Detailed implementation manners

[0031] The present invention will be further described below in conjunction with embodiments.

[0032] Please refer to Figures 1-3 , the present invention provides an embodiment: a process for manufacturing solid silicon carbide, the process for manufacturing solid silicon carbide includes a large reactor 1, a jet nozzle 2, a cavity 100, an exhaust pipeline 200, a vacuum pump 300, a primary tail gas equipment 400, a secondary tail gas equipment 500, a neutralization water treatment system 6, and an electric heater 700; jet nozzles 2 for introducing reaction gases into the reactor are vertically and evenly distributed outside the large reactor 1; a cavity 100 is provided inside the large reactor 1; one end of the exhaust pipeline 200 of the cavity 100 is equipped with a vacuum pump 300; a primary tail gas equipment 400 and a secondary tail gas equipment 500 are successively installed at the exhaust end of the vacuum pump 300; an electric heater 700 is arranged inside the exhaust pipeline 200; a neutralization water treatment system 6 is connected in series at the lower end of the electric heater 700.

[0033] Among them, the shape of the jet nozzle 2 is composed of parallel injection, a shunt nozzle installed at 60° up and down, and a shunt nozzle installed at 120°.

[0034] Preferably, the jet nozzle 2 adopts shunt nozzles installed at 60° and 120° to make the deposition of the substrate uniform.

[0035] Preferably, by means of the shunt nozzle at the front end, the effect of reducing the concentration difference between two gases between the stages is achieved. Actually, if the molar fraction of argon is confirmed at a position at a certain interval from the center of the reactor along the z-axis on the stage, it can be confirmed that at the average concentration between the stages, compared with the case without a shunt nozzle, in the case of having a nozzle, the gas concentration difference between the upper and lower stages has a tendency to decrease.

[0036] Preferably, especially when the 120° nozzle is installed, it is confirmed that the molar fraction difference of argon between the stages is the smallest.

[0037] Preferably, the neutralization water treatment system 6 includes a pressure control valve 601, a water-cooled jacket 602, a throttle valve 603, and a particle filter 604; the pressure control valve 601 is located at the very front end of the treatment process; the water-cooled jacket 602 is immediately behind the pressure control valve 601; a throttle valve 603 is installed at the output end of the water-cooled jacket 602; the particle filter 604 is located after the throttle valve 603; the particle filter 604 is the last component in the entire treatment process.

[0038] Preferably, the method for positioning the manufacture of solid silicon carbide: By directly coating each substrate with a spraying gas for the loading position, it has the effect of improving the deposition uniformity.

[0039] When working: Preferably, first, the nozzle of the gas jet port 2 of the cavity 100 is improved. The shape of the nozzle can be composed of parallel injection, installing a split nozzle at 60° up and down, and installing a split nozzle at 120°. The overall concentration distribution has no significant difference in appearance, and it has the effect of reducing the concentration difference between the two gases between the stages through the split nozzle at the front end. In fact, if the argon mole fraction at a certain distance from the center of the reactor is confirmed on the stage along the z-axis, it can be confirmed that at the average concentration between the stages, compared with the case without a split nozzle, when there is a nozzle, the gas concentration difference between the upper and lower stages has a tendency to decrease. In particular, when the 120° nozzle is installed, it is confirmed that the mole fraction difference of argon between the stages is the smallest, and it is characterized by this;

[0040] Next, by directly coating each substrate with a spraying gas for the loading position, it has the effect of improving the deposition uniformity, and a relatively uniform deposition efficiency can be obtained;

[0041] Finally, the hydrogen gas discharged in the SiC-CVD deposition process can be discharged at a concentration lower than the safety standard after being fully combusted by the electric heater 700. In addition, other tail gases such as unreacted MTS and hydrogen chloride HCl generated in the SiC-CVD deposition process can also be neutralized by the water treatment system 6 at a concentration lower than the safety standard. For the above treatment, the unreacted substances and gases after the collection process can be collected and effectively managed. The high-temperature unreacted substances and gases are cooled by the water-cooled jacket 602. After the gas is first collected by the cold trap Cold tarp, two or more particle filters 604 are connected in series to collect particles more effectively and minimize the damage to the dry pump, including the throttle valve 603, so as to maintain and adjust a certain process pressure during the SiC-CVD process. In addition, in order to effectively replace the cold trap and the filter, manual valves are installed at the front and rear ends, which can solve the problem of the oxidation of the exhaust pipe line 200 due to the remaining unreacted substances and gases.

[0042] The following table shows the argon mole fraction at a certain distance from the center of the reactor after the nozzle is installed

Claims

1. A process for manufacturing solid silicon carbide, characterized in that: The invention comprises a large reactor (1), an air jet (2), a cavity (100), an exhaust pipeline (200), a vacuum pump (300), a primary tail gas device (400), a secondary tail gas device (500), a neutralization water treatment system (6), and an electric heater (700); the air jet (2) for introducing reaction gas into the reactor is evenly distributed vertically on the outside of the large reactor (1); a cavity (100) is arranged inside the large reactor (1); a vacuum pump (300) is installed at one end of the exhaust pipeline (200) of the cavity (100); the primary tail gas device (400) and the secondary tail gas device (500) are installed in sequence at the exhaust end of the vacuum pump (300); an electric heater (700) is arranged inside the exhaust pipeline (200); and the neutralization water treatment system (6) is connected in series at the lower end of the electric heater (700); The shape of the jet nozzle (2) is composed of parallel injection, a split nozzle installed at 60 degrees up and down, and a split nozzle installed at 120 degrees.

2. The solid silicon carbide manufacturing process according to claim 1, characterized in that: The air jet (2) adopts a split nozzle installed at 60° and 120° to ensure uniform deposition of the substrate.

3. The solid silicon carbide manufacturing process according to claim 2, characterized in that: The difference in concentration of the two gases between the stages is reduced by the diverter nozzle at the front end. In fact, by confirming the mole fraction of argon at a certain distance from the center of the reactor on the stage along the z-axis, it can be confirmed that at the average concentration between the stages, the difference in gas concentration between the upper and lower stages tends to decrease when there is a nozzle compared to when there is no diverter nozzle.

4. The solid silicon carbide manufacturing process according to claim 2, characterized in that: In particular, when the 120° nozzle was installed, it was confirmed that the difference in the mole fraction of argon between the stages was minimal.

5. The solid silicon carbide manufacturing process according to claim 1, characterized in that: The neutralization water treatment system (6) comprises a pressure control valve (601), a water cooling jacket (602), a throttle valve (603), and a particle filter (604); the pressure control valve (601) is located at the front end of the treatment process; the rear end of the pressure control valve (601) is immediately connected to the water cooling jacket (602); the throttle valve (603) is installed at the output end of the water cooling jacket (602); the particle filter (604) is located after the throttle valve (603); and the particle filter (604) is the last component of the entire treatment process.

6. The solid silicon carbide manufacturing process according to claim 1, characterized in that: Solid SiC manufacturing positioning method: Deposition uniformity is improved by directly coating each substrate with the spray gas used for loading position.

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