SiC substrate manufacturing method

Abstract

A method for manufacturing a SiC substrate according to an embodiment of the present invention includes the steps of providing a base, forming either an n-type or p-type SiC thin film on the base, and separating the SiC thin film from the base, and the step of forming the SiC thin film includes the steps of injecting a source gas containing silicon (Si) onto the base, a primary purge step of injecting a purge gas after the injection of the source gas is interrupted, injecting a reactant gas containing carbon (C) after the interruption of the primary purge, and a secondary purge step of injecting a purge gas after the injection of the reactant gas is interrupted. Therefore, according to the embodiment of the present invention, a SiC substrate can be provided by depositing a SiC thin film at a low temperature, which can reduce the power or time required to raise the temperature of the base for forming the SiC thin film.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a SiC substrate, and more particularly to a method for manufacturing a SiC substrate by forming a SiC thin film by atomic layer deposition. [Background technology]

[0002] A semiconductor device, for example, a field effect transistor, includes a substrate, a pair of well regions spaced apart from each other in the substrate, a channel formed between the pair of well regions on the substrate, source and drain electrodes formed on the top of each of the pair of well regions, a gate insulating layer formed between the source electrode and the drain electrode, and a gate electrode formed on the top of the gate insulating layer.

[0003] A SiC substrate is used as the substrate for such semiconductor devices. The SiC substrate is prepared by depositing a SiC thin film on a base by chemical vapor deposition (CVD), and then removing the base to separate the SiC thin film.

[0004] However, in order to deposit a SiC thin film on a base by chemical vapor deposition, the base must be heated to a high temperature, which increases the power required to deposit the SiC thin film and takes a long time. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Republic of Korea Patent No. 10-1001674 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a method for producing a SiC substrate that can be produced at low temperatures.

[0007] The present invention provides a method for manufacturing a SiC substrate, which can be manufactured by depositing a SiC thin film at a low temperature. [Means for solving the problem]

[0008] A method for manufacturing a SiC substrate according to an embodiment of the present invention includes the steps of providing a base, forming either an n-type or p-type SiC thin film on the base, and separating the SiC thin film from the base, and the step of forming the SiC thin film may include the steps of injecting a source gas containing silicon (Si) onto the base, a first purge step of injecting a purge gas after interrupting the injection of the source gas, injecting a reactant gas containing carbon (C) after interrupting the first purge, and a second purge step of injecting a purge gas after interrupting the injection of the reactant gas.

[0009] The source gas may include at least one of SiH4 and Si2H6.

[0010] The reactant gas may include at least one of C3H8 and SiH3CH3.

[0011] The step of injecting the reactant gas may include the step of generating a plasma.

[0012] The step of generating a plasma may include the step of injecting hydrogen gas.

[0013] The step of forming the SiC thin film may include a step of repeatedly performing one process cycle in which the source gas injection step, the first purge step, the reactant gas injection step, and the second purge step are performed in this order.

[0014] The step of forming the SiC thin film may include a step of injecting a doping gas, and the doping gas may be injected during the injection of the source gas, or may be injected after the injection of the source gas is stopped and before the first purging step.

[0015] The doping gas may include a gas containing at least one of N (nitrogen) and P (phosphorus), or may include a gas containing at least one of Al (aluminum), B (boron), and Ga (gallium).

[0016] The base may include any one of graphite, Si (silicon), Ga (gallium), and glass. [Effects of the Invention]

[0017] According to an embodiment of the present invention, a SiC substrate can be provided by depositing a SiC thin film at a low temperature, which reduces the power or time required to heat the base to form the SiC thin film. [Brief explanation of the drawings]

[0018] [Figure 1] 2 is a conceptual diagram showing a state in which a SiC thin film is formed on a base by a method according to an embodiment of the present invention. FIG. [Figure 2] FIG. 10 is a conceptual diagram showing a state in which the base and the SiC thin film are separated and an SiC substrate is provided. [Figure 3] 1 is a diagram showing an example of a field effect transistor to which a SiC substrate manufactured by a method according to an embodiment of the present invention is applied. [Figure 4] 1 is a conceptual diagram illustrating a method for forming a SiC thin film on a base according to an embodiment of the present invention. [Figure 5] 1 is a schematic diagram illustrating a deposition apparatus used to deposit a SiC thin film for manufacturing a SiC substrate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, the embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided merely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art. The drawings may be exaggerated to illustrate the embodiments of the present invention, and the same reference numerals in the drawings refer to the same components.

[0020] An embodiment of the present invention relates to a method for manufacturing a substrate. More particularly, the present invention relates to a method for manufacturing a SiC substrate in which a SiC thin film is formed on a base by atomic layer deposition (ALD). More particularly, the present invention relates to a method for manufacturing a SiC substrate in which an n-type or p-type SiC thin film is formed on a base by atomic layer deposition (ALD).

[0021] Fig. 1 is a conceptual diagram showing a state in which a SiC thin film is formed on a base by a method according to an embodiment of the present invention. Fig. 2 is a conceptual diagram showing a state in which the base and the SiC thin film are separated and a SiC substrate is provided. Fig. 3 is a diagram showing an example of a field-effect transistor to which a SiC substrate manufactured by a method according to an embodiment of the present invention is applied.

[0022] Referring to FIG. 1, the SiC thin film 10 may be formed by deposition on at least one surface of the base B, for example, on the top surface of the base B.

[0023] The base B may be made of a material containing any one of graphite, silicon (Si), gallium (Ga), and glass. More specifically, the base B may be any one of a graphite plate, a wafer, and a glass plate. The wafer used as the base B may be any one of a Si wafer, a SiC wafer, a SiO2 (quartz) wafer, and a GaAs wafer.

[0024] The SiC thin film 10 is formed by an atomic layer deposition (ALD) method, and may be formed to be an n-type or a p-type.

[0025] Once the SiC thin film 10 having a predetermined or target thickness is formed on the base B, the SiC thin film is separated from the base B or the base B is removed, as shown in FIG. 2. The SiC thin film 10 separated from the base B or from which the base B has been removed can be used as a substrate for manufacturing a semiconductor device. For this reason, the SiC thin film 10 separated from the base B can be referred to as a substrate or a SiC substrate.

[0026] For ease of explanation, the SiC thin film formed on the upper portion of the base B will be denoted by the reference numeral "10" as shown in Fig. 1. In this case, since a plurality of SiC thin films are stacked, each of the plurality of SiC thin films may be referred to as the reference numeral "10."

[0027] After the formation of the SiC thin film 10 is completed, the base B is removed or separated as described above. At this time, as shown in FIG. 2, the SiC thin film 10 from which the base B has been removed or separated is referred to as a SiC substrate, and the SiC substrate is denoted by the reference symbol "S."

[0028] The SiC thin film 10 formed by the method according to the embodiment of the present invention, i.e., the SiC substrate S, can be used as a substrate for a semiconductor device. For example, the SiC substrate according to the embodiment can be used as a substrate S for a field effect transistor. More specifically, with reference to FIG. 3 , the field effect transistor may include a substrate S, a pair of well regions 22 a, 22 b provided in the substrate S so as to be spaced apart from each other in the width direction, a channel 21 provided between the pair of well regions 22 a, 22 b, source and drain electrodes 23 a, 23 b provided on the pair of well regions 22 a, 22 b, respectively, a gate insulating layer 24 formed between the source electrode 23 a and the drain electrode 23 b, and a gate electrode 25 formed on the gate insulating layer 24.

[0029] Here, the substrate S may be a substrate manufactured by the method according to the embodiment. That is, the substrate S may be provided by forming a SiC thin film 10 on the top of a base B by the method according to the embodiment (see FIG. 1), and then separating the SiC thin film 10 from the base B or removing the base B (see FIG. 2). The SiC substrate S may also be provided as an n-type or p-type by atomic layer deposition.

[0030] The well regions 22a and 22b may be n-type or p-type. That is, when the substrate S is n-type, the well regions 22a and 22b may be p-type, and when the substrate S is p-type, the well regions 22a and 22b may be n-type. Here, the well region 22a formed in contact with the source electrode 23a or below the source electrode 23a may be a layer that functions as the source of a field-effect transistor. Furthermore, the well region 22b formed in contact with the drain electrode 23b or below the drain electrode 23b may be a layer that functions as the drain of a field-effect transistor.

[0031] Such well regions 22a, 22b may be formed by removing a portion of a thin film for forming a gate insulating layer formed on the upper surface of the substrate S, and then injecting a dopant material into the removed region. Once such a pair of well regions 22a, 22b is formed, a channel 21 is formed between the pair of well regions 22a, 22b.

[0032] The source and drain electrodes 23a, 23b are formed on the upper portions of the pair of well regions 22a, 22b, respectively. That is, the source electrode 23a is formed on the upper portion of one of the pair of well regions 22a, and the drain electrode 23b is formed on the upper portion of the other well region 22b. In this case, the source and drain electrodes 23a, 23b are formed from a material containing metal, and may be formed from at least one of Ti and Au, for example.

[0033] The gate insulating layer 24 may be formed between the source electrode 23a and the drain electrode 23b and located above the channel 21. The gate insulating layer 24 may be made of any one of SiO2, SiON, and Al2O3.

[0034] The gate electrode 25 may be formed on the gate insulating layer 24 so as to be located between the source electrode 23 a and the drain electrode 23 b. In this case, the gate electrode 25 may be formed from a material containing a metal, for example, a material containing at least one of Ti and Au.

[0035] In the above, the SiC substrate S manufactured by the method according to the embodiment has been described as being used as a substrate for a field-effect transistor. However, the present invention is not limited to this, and the SiC substrate can be used for a wide variety of semiconductor devices.

[0036] FIG. 4 is a conceptual diagram for explaining a method for forming a SiC thin film on a base by a method according to an embodiment of the present invention.

[0037] Hereinafter, a method for forming a SiC thin film according to an embodiment of the present invention will be described with reference to FIGS.

[0038] First, a base B is provided. In this case, the base B may be, for example, a disk made of graphite.

[0039] 1, a SiC thin film 10 is deposited on one surface, for example, the upper surface, of the base B. At this time, the SiC thin film 10 may be formed by atomic layer deposition (ALD), and multiple SiC thin films 10 may be stacked.

[0040] 4, the method for forming the SiC thin film 10 using the atomic layer deposition (ALD) method may include a step of injecting a source gas, a step of injecting a purge gas (first purge), a step of injecting a reactant gas, and a step of injecting a purge gas (second purge). In this case, the injection of the source gas, the injection of the purge gas (first purge), the injection of the reactant gas, and the injection of the purge gas (second purge) may be performed in this order.

[0041] In this case, the source gas may be a gas containing Si. The Si-containing gas may be, for example, a gas containing at least one of SiH4 and Si2H6. The reactive gas may be a gas containing C (carbon). The C (carbon)-containing gas may be, for example, a gas containing at least one of C3H8 and SiH3CH3.

[0042] Furthermore, a doping gas is injected to form an n-type or p-type SiC thin film 10. The doping gas may be a gas containing at least one of an N (nitrogen)-containing gas and a P (phosphorus)-containing gas, or a gas containing at least one of an Al (aluminum)-containing gas, a B (boron)-containing gas, and a Ga (gallium)-containing gas. That is, when forming an n-type SiC thin film 10, the doping gas may be at least one of an N (nitrogen)-containing gas and a P (phosphorus)-containing gas. As another example, when forming a p-type SiC thin film 10, the doping gas may be at least one of an Al (aluminum)-containing gas, a B (boron)-containing gas, and a Ga (gallium)-containing gas.

[0043] The doping gas may be injected together with the source gas when the source gas is injected, or may be injected after the source gas injection is completed and before the first purge.

[0044] For example, when the source gas and the doping gas are injected together, the step of forming the SiC thin film 10 may be performed in the following order: injection of the source gas and the doping gas, injection of the purge gas (first purge), injection of the reactant gas, and injection of the purge gas (second purge). In this case, the doping gas may be mixed with the source gas and injected. Needless to say, the doping gas is injected when the source gas is injected, but the injection paths of the source gas and the doping gas may be different from each other. In this way, when the source gas and the doping gas are injected together to form the SiC thin film 10, the above-mentioned "injection of the source gas and the doping gas-injection of the purge gas (first purge)-injection of the reactant gas-injection of the purge gas (second purge)" may be one process cycle for forming the SiC thin film 10.

[0045] As another example, the source gas and the doping gas may be injected in separate steps. That is, the doping gas may be injected after the injection of the source gas is completed. In this case, the step of forming the SiC thin film may be performed in the following order: injection of the source gas, injection of the doping gas, injection of the purge gas (first purge), injection of the reactant gas, and injection of the purge gas (second purge). In addition, when forming the SiC thin film 10, the above-described "injection of the source gas-injection of the doping gas-injection of the purge gas (first purge)-injection of the reactant gas-injection of the purge gas (second purge)" may be combined into one process cycle for forming the SiC thin film.

[0046] In the reactant gas injection step of the process cycle described above, plasma may be generated. At this time, hydrogen gas may be injected to generate plasma from the hydrogen gas. That is, hydrogen gas may be injected together with the reactant gas, and the hydrogen gas may be discharged to generate plasma from the hydrogen gas. By generating plasma during the injection of the reactant gas in this manner, a SiC thin film can be deposited at a low temperature of 300°C to 600°C.

[0047] Furthermore, the plasma generated by the hydrogen gas, i.e., hydrogen plasma, can remove impurities from the SiC thin film or the space (reaction space) where the SiC thin film is deposited. Here, the impurities may be, for example, reaction by-products resulting from the reaction between the source gas and the reactant gas. The hydrogen plasma can decompose impurities, for example, reaction by-products resulting from the reaction between the source gas and the reactant gas. This makes it easier to exhaust the reaction by-products through an exhaust unit connected to the reaction space. Therefore, impurities present in the reaction space or the SiC thin film can be effectively removed.

[0048] By repeating the above-described process cycle multiple times, multiple atomic layer depositions are performed. In other words, multiple SiC thin films 10 are stacked by multiple atomic layer depositions. Then, by adjusting the number of process cycles to be performed, it is possible to form SiC thin films 10 with a target thickness.

[0049] Meanwhile, in the past, a SiC substrate was prepared by depositing a SiC thin film on a base B by chemical vapor deposition. At this time, the support 200 supporting the base B or the base B was maintained at a high temperature of about 1200°C. In other words, the SiC thin film can be deposited on the upper surface of the base B only after the support 200 or the base B is maintained at a high temperature of 1200°C. In this case, there is a problem that the support 200 or the base must be heated to a high temperature. Therefore, there are problems such as an increase in the power required to deposit the SiC thin film and a long time required.

[0050] However, in the embodiment, the SiC thin film 10 is deposited by atomic layer deposition, which allows the SiC thin film 10 to be deposited at a lower temperature than conventional methods, thereby reducing the power required to deposit the SiC thin film 10.

[0051] FIG. 5 is a schematic diagram of a deposition apparatus used to deposit a SiC thin film for manufacturing a SiC substrate according to an embodiment of the present invention.

[0052] The deposition apparatus may be an apparatus for depositing a thin film by atomic layer deposition (ALD). More specifically, it may be an apparatus for forming the SiC thin film 10 on the base B.

[0053] As shown in FIG. 5, the deposition apparatus may include a chamber 100, a support 200 disposed within the chamber 100 to support a base B, an injection unit 300 disposed opposite the support 200 to inject a process gas (hereinafter, referred to as a process gas) into the chamber 100, a gas supply unit 400 for providing the process gas to the injection unit 300, first and second gas supply pipes 500a and 500b connected to the injection unit 300 with different paths and for supplying the gas from the gas supply unit 400 to the injection unit 300, and an RF power supply unit 600 for supplying power to generate plasma within the chamber 100.

[0054] The deposition apparatus may further include a driving unit 700 that causes the support stand 200 to perform at least one of a lifting and a rotating operation, and an exhaust unit (not shown) that is arranged to be connected to the chamber 100.

[0055] The chamber 100 may have an internal space in which a thin film can be formed on the base B that has been carried inside. For example, the cross-sectional shape may be a square, pentagon, hexagon, or the like. Needless to say, the internal shape of the chamber 100 can be changed in various ways, and it is preferable that the shape be set to correspond to the shape of the base B.

[0056] The support 200 is disposed inside the chamber 100 to face the spray unit 300 and supports the base B placed inside the chamber 100. A heater 210 may be provided inside the support 200. When the heater 210 is operated, the base B placed on the support 200 and the inside of the chamber 100 can be heated.

[0057] In addition to the heater 210 provided on the support 200, a separate heater may be provided inside or outside the chamber 100 as a means for heating the inside of the base B or the chamber 100.

[0058] The injection section 300 may include a first plate 310 having a plurality of holes (hereinafter referred to as holes) 311 arranged in the extension direction of the support base 200 and spaced apart from one another, and arranged inside the chamber 100 so as to face the support base 200, a plurality of nozzles 320 arranged so that at least a portion of each nozzle 320 is fitted into each of the plurality of holes 311, and a second plate 330 arranged inside the chamber 100 so as to be positioned between the upper wall of the chamber 100 and the first plate 310.

[0059] Additionally, the injection unit 300 may further include an insulating unit 340 positioned between the first plate 310 and the second plate 330 .

[0060] The first plate 310 may be in the form of a plate extending in the extension direction of the support base 200. The first plate 310 is provided with a plurality of holes 311, and each of the plurality of holes 311 may be provided so as to penetrate the first plate 310 in the up-down direction. The plurality of holes 311 may be aligned in the extension direction of the first plate 310 or the support base 200.

[0061] Each of the plurality of nozzles 320 may have a shape extending in the vertical direction, have a passage therein through which gas can pass, and may have a shape with open upper and lower ends. Each of the plurality of nozzles 320 may be arranged so that at least its lower portion is fitted into a hole 311 formed in the first plate 310, and its upper portion is connected to the second plate 330. For this reason, the nozzles 320 can be described as having a shape that protrudes downward from the second plate 330.

[0062] The outer diameter of the nozzle 320 may be set to be smaller than the inner diameter of the hole 311. The nozzle 320 may be arranged so that the outer peripheral surface of the nozzle 320 is separated from the wall around the hole 311 (i.e., the inner wall of the first plate 310) when the nozzle 320 is fitted into the inside of the hole 311. Therefore, the inside of the hole 311 can be separated into an outer space of the nozzle 320 and an inner space of the nozzle 320.

[0063] The passage within nozzle 320 in the internal space of hole 311 is a passage through which gas from first gas supply pipe 500a moves and is sprayed. The space outside nozzle 320 in the internal space of hole 311 is a passage through which gas from second gas supply pipe 500b moves and is sprayed. Therefore, hereinafter, the passage within nozzle 320 will be referred to as first path 360a, and the space outside nozzle 320 inside hole 311 will be referred to as second path 360b.

[0064] The second plate 330 may be disposed such that its upper surface is separated from the upper wall of the chamber 100 and its lower surface is separated from the first plate 310. This allows for an empty space to be provided between the second plate 330 and the first plate 310 and between the second plate 330 and the upper wall of the chamber 100.

[0065] Here, the space above the second plate 330 is a space (hereinafter referred to as diffusion space 350) through which gas from the first gas supply pipe 500a spreads and moves, and may be in communication with the upper openings of the plurality of nozzles 320. In other words, the diffusion space 350 is a space in communication with the plurality of first paths 360a. Therefore, the gas that has passed through the first gas supply pipe 500a spreads in the extension direction of the second plate 330 in the diffusion space 350, and then passes through the plurality of first paths 360a to be injected downward.

[0066] Further, a deep hole (not shown) that is a passage through which gas moves is provided inside the second plate 330, and the deep hole may be connected to the second gas supply pipe 500b and provided so as to communicate with the second path 360b. Therefore, the gas from the second gas supply pipe 500b can be injected toward the base B via the deep hole in the second plate 330 and the second path 360b.

[0067] The gas supply unit 400 provides gases required for depositing a thin film by atomic layer deposition. The gas supply unit 400 includes a source gas reservoir 410 for storing a source gas, a doping gas reservoir 420 for storing a doping gas, a reactant gas reservoir 430 for storing a reactant gas that reacts with the source gas, and a purge gas reservoir 440 for storing a purge gas. The gas supply unit 400 may further include a hydrogen gas reservoir (not shown) for storing hydrogen gas.

[0068] Here, the purge gas stored in the purge gas storage section 440 may be, for example, N2 gas or Ar gas.

[0069] The gas supply section 400 may also include a first transfer pipe 450a arranged to connect the source gas storage section 410 and the doping gas storage section 420 to the first gas supply pipe 500a, and a second transfer pipe 450b arranged to connect the reactant gas storage section 430 and the purge gas storage section 440 to the second gas supply pipe 500b.

[0070] The gas supply unit 400 may further include a mixer 460 that mixes the gas from the doping gas reservoir 420 with the gas from the source gas reservoir.

[0071] The gas supply section 400 may also include a plurality of first connecting pipes 470a connecting each of the source gas storage section 410 and the doping gas storage section 420 to the first transfer pipe 450a, a valve disposed on each of the plurality of first connecting pipes 470a, a plurality of second connecting pipes 470b connecting each of the reactant gas storage section 430 and the purge gas storage section 440 to the second transfer pipe 450b, and a valve disposed on each of the plurality of second connecting pipes 470b.

[0072] The hydrogen gas storage unit may be connected to the first transfer pipe 450a, or a connecting pipe may be provided between the hydrogen gas storage unit and the first transfer pipe 450a.

[0073] The mixing unit 460 may be a means provided to have an internal space in which gases can be mixed. Alternatively, the mixing unit 460 may be arranged to connect the first transfer pipe 450a to a first connection pipe 470a connected to the source gas storage unit 410 and the doping gas storage unit 420, respectively. Therefore, the source gas and the doping gas flowing into the mixing unit 460 can be mixed inside the mixing unit 460 and then transferred to the first gas supply pipe 500a via the first transfer pipe 450a. In this case, the source gas and the doping gas flow into the injection unit 300 in a mixed state, and the mixed gas is injected through the first path 360a of the injection unit 300.

[0074] Needless to say, the source gas and the doping gas may be delivered to the first gas supply pipe 500a at different times without being mixed.

[0075] In the above description, the source gas storage portion 410 and the doping gas storage portion 420 are connected to the same first transfer pipe 450a and injected through the first path 360a. However, the present invention is not limited to this. The source gas storage portion 410 and the doping gas storage portion 420 may be connected to each other so as to be injected through different paths. For example, the source gas storage portion 410 may be connected to the first transfer pipe 450a, and the doping gas storage portion 420 may be connected to the second transfer pipe 450b. In this case, the source gas may flow into the first path 360a of the injection unit 300 via the first transfer pipe 450a and the first gas supply pipe 500a and be injected, and the doping gas may flow into the second path 360b of the injection unit 300 via the second transfer pipe 450b and the second gas supply pipe 500b and be injected.

[0076] 1, 2 and 5, a method for manufacturing a SiC substrate according to an embodiment of the present invention will be described below, taking a method for forming an n-type SiC thin film as an example.

[0077] First, the heater 210 provided on the support table 200 is operated to heat the support table 200. At this time, the heater is operated so that the temperature of the support table 200 or the base B to be placed on the support table 200 becomes a process temperature, for example, 300°C to 600°C.

[0078] Next, base B, for example, a Si wafer, is loaded into chamber 100 and placed on support stage 200. After this, when base B placed on support stage 200 reaches a target process temperature, for example, 300°C to 600°C, a SiC thin film 10 is formed on base B as shown in FIG.

[0079] At this time, the SiC thin film 10 is formed by atomic layer deposition. That is, the SiC thin film 10 is formed on the base B by atomic layer deposition, which involves the injection of a source gas, the injection of a purge gas (first purge), the injection of a reactant gas, and the injection of a purge gas (second purge) in this order.

[0080] At this time, the doping gas may be mixed with the source gas and injected. Alternatively, hydrogen gas may be injected when injecting the reactant gas, and the RF power supply unit 600 may be operated to generate plasma inside the chamber 100. In such a case, the process cycle for forming the SiC thin film 10 by atomic layer deposition may be "injection of source gas and doping gas - injection of purge gas (first purge) - injection of reactant gas (plasma generation) - injection of purge gas (second purge)." The above-described process cycle is repeated multiple times to deposit multiple SiC thin films, thereby forming the SiC thin film 10 with a target thickness.

[0081] Hereinafter, a method for forming the SiC thin film 10 by injecting the process gas into the chamber 100 using the injection unit 300 and the gas supply unit 400 will be described in more detail.

[0082] First, a source gas and a doping gas are injected into the chamber 100. To this end, the source gas stored in the source gas storage section 410 and the doping gas stored in the doping gas storage section 420 are supplied to the mixing section 460. Therefore, the source gas and the doping gas are mixed inside the mixing section 460. At this time, the source gas may be a Si-containing gas, and the doping gas may be an N (nitrogen)-containing gas.

[0083] The mixed gas obtained by mixing the source gas and the doping gas flows through the first transfer pipe 450a and the first gas supply pipe 500a into the diffusion space 350 in the injection unit 300. After the mixed gas is distributed throughout the diffusion space 350, it passes through the multiple nozzles 320, i.e., the multiple first paths 360a, and is injected toward the base B.

[0084] Although the source gas and the doping gas are mixed and injected in the above description, the present invention is not limited to this, and the source gas and the doping gas may be injected separately without being mixed.

[0085] When the injection of the source gas and the doping gas, i.e., the mixed gas, is stopped or finished, a purge gas is supplied through the purge gas reservoir 440 to inject the purge gas into the chamber 100 (first purge). At this time, the purge gas discharged from the purge gas reservoir 440 may pass through the second connecting pipe 470b, the second transfer pipe 450b, and the second gas supply pipe 500b, and then be injected downward through the second path 360b.

[0086] Next, a reactant gas, for example, a C (carbon)-containing gas, is provided from the reactant gas reservoir 430 and injected into the chamber 100. The reactant gas may be injected into the chamber 100 through the same route as the purge gas. That is, the reactant gas may be injected downward through the second path 360b after passing through the second connecting pipe 470b, the second transfer pipe 450b, and the second gas supply pipe 500b. When the reactant gas is injected, a reaction may occur between the source gas adsorbed on the base B and the reactant gas, producing a reactant, i.e., SiC. The reactant is then deposited or evaporated on the base B, thereby depositing the SiC thin film 10 on the base B. The doping gas adsorbed on the base B deposits the n-type SiC thin film 10.

[0087] When the reactant gas is injected in this manner, hydrogen gas may be injected into the chamber 100, and the RF power supply unit 600 may be operated to supply RF power to the first plate 310. When RF power is supplied to the first plate 310, plasma may be generated in the second passage 360b in the injection unit 300 and in the space between the first plate 310 and the support 200.

[0088] When the injection of the reactant gas is stopped, the purge gas is supplied through the purge gas reservoir 440 to inject the purge gas into the chamber 100 (second purge). At this time, by-products resulting from the reaction between the source gas and the reactant gas may be discharged to the outside of the chamber 100 by the second purge.

[0089] The process cycle described above, which is performed in the order of "injection of source gas and doping gas, injection of purge gas (first purge), injection of reactant gas, and injection of purge gas (second purge)," may be repeated multiple times. The number of times the process cycle should be performed may be determined depending on the target film thickness.

[0090] Once the SiC thin film 10 with the target thickness has been formed, the SiC thin film 10 is separated from the base B, as shown in Fig. 2. At this time, for example, the base B may be removed by a polishing method to separate the SiC thin film 10. Needless to say, the method is not limited to a polishing method, and any method may be used as long as it is possible to remove the base B and separate the SiC thin film 10 from the base B.

[0091] In this way, when the SiC thin film 10 is separated from the base B, a substrate S that can be used as a substrate for a semiconductor device, i.e., a SiC substrate S, is provided. The SiC substrate S manufactured by this method can be used as a substrate for manufacturing a semiconductor device, for example, a field effect transistor.

[0092] As described above, according to the method for manufacturing the SiC substrate S of the embodiment, the SiC thin film 10 is deposited on the base by atomic layer deposition. Therefore, the SiC thin film 10 can be deposited at a lower temperature than conventional methods. This has the effect of reducing the power required to manufacture the SiC substrate S or to deposit the SiC thin film 10. [Industrial Applicability]

[0093] According to an embodiment of the present invention, a SiC substrate can be provided by depositing a SiC thin film at a low temperature, which reduces the power or time required to heat the base to form the SiC thin film.

Claims

1. providing a base; forming an n-type or p-type SiC thin film on the base; separating the SiC thin film from the base; Including, The step of forming the SiC thin film includes: injecting a source gas containing silicon (Si) onto the base; a first purge step of injecting a purge gas after the injection of the source gas is stopped; injecting a reactant gas containing carbon (C) after the primary purge is interrupted; a secondary purge step of injecting a purge gas after the injection of the reactant gas is stopped; Including, The method for manufacturing a SiC substrate, wherein the step of injecting the reactant gas includes the step of generating plasma.

2. The source gas is SiH ４ and Si ２ H ６ The method for manufacturing a SiC substrate according to claim 1 , comprising at least one of:

3. The reactant gas is C ３ H ８ and SiH ３ CH ３ The method for manufacturing a SiC substrate according to claim 1 , comprising at least one of:

4. The method for manufacturing a SiC substrate according to claim 1 , wherein the step of generating the plasma includes the step of injecting hydrogen gas.

5. The step of forming the SiC thin film includes:

5. The method for manufacturing a SiC substrate according to claim 1, further comprising the step of repeatedly performing one process cycle in which the source gas injection step, a first purge step, a reactant gas injection step, and a second purge step are performed in this order.

6. The step of forming the SiC thin film includes a step of injecting a doping gas; 5. The method for manufacturing a SiC substrate according to claim 1, wherein the doping gas is injected during injection of the source gas, or is injected after injection of the source gas is stopped and before the first purge step.

7. The doping gas is a gas containing at least one of N (nitrogen) and P (phosphorus), or 7. The method for producing a SiC substrate according to claim 6, wherein the gas contains at least one of Al (aluminum), B (boron), and Ga (gallium).

8. The method for manufacturing a SiC substrate according to claim 1 , wherein the base includes any one of graphite, Si (silicon), Ga (gallium), and glass.

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