Apparatus and method for manufacturing semiconductor thin film crystal growth

Abstract

The present invention relates to a semiconductor crystal thin film growth apparatus comprising silicon and nitride semiconductors, comprising: a reaction tube; a reaction boat disposed within the reaction tube; a halogenation reaction gas supply pipe for supplying a halogenation reaction gas to the reaction boat; a nitridation reaction gas supply pipe for supplying a nitridation reaction gas to the reaction boat; and a heating unit for heating the reaction tube. The reaction boat comprises a raw material mounting section in which a mixed raw material comprising solid aluminum and gallium is mounted; and a crystal growth section disposed above or below the raw material mounting section in which a substrate set is disposed. The crystal growth section includes at least one substrate mounting chamber. At this time, the raw material mounting section and the crystal growth section are in communication with each other through at least one through hole. The mixed raw material may further include silicon. Preferably, a ledge of a predetermined height is formed in the through hole toward the raw material mounting section. A substrate set is formed by stacking two substrates, wherein a target crystal material is deposited as an amorphous thin film on each substrate, and the amorphous thin film surfaces of each substrate are arranged to face each other to form a substrate set.

Description

Technology Field

[0001] The present invention relates to an apparatus and method for growing a semiconductor crystal thin film, and more specifically, to an apparatus and method for growing a semiconductor crystal thin film selected from the group including silicon (Si) and nitride semiconductors using a hydrogen vapor phase growth (HVPE) method using mixed raw materials. Background Technology

[0002] Silicon carbide (SiC) is attracting attention as the most important material for high-temperature, high-power, high-frequency, and low-loss device applications due to its wide energy bandgap, high breakdown voltage, and high thermal conductivity [1-5]. SiC crystals were first grown by the sublimation method proposed by Lely in 1955 [6]. Tairov and Tsvetkov et al. proposed a physical vapor transport (PVT) process based on the sublimation process (seeded sublimation), which has become the standard method for producing SiC bulk materials today and a core technology for SiC crystal growth [7-14]. This allows for the growth of crystals that retain the properties of the substrate (superstructure) by controlling the saturation within the growth device to supersaturation, oversaturation, and saturation states.

[0003] Generally, crystal growth in a supersaturated state is determined solely by the supersaturated source material, regardless of the substrate's properties (superstructure), and in such cases, it grows into a hexagonal structure according to the laws of nature. To grow SiC crystals, it is necessary to precisely control and adjust the gas pressure from the feedstock supply during the long growth process within the reaction tube. Since the feedstock and the crystal nuclei for the single-crystal layer are placed in a single reaction crucible, there is a disadvantage in that it is difficult to obtain stable crystals due to temperature uniformity and the influence of impurities in the source. Therefore, in 1970, a technique named the so-called sublimation sandwich method (SSM), which was developed by modifying sublimation technology, was proposed for the growth of single-crystal bulk and epitaxial layers [15-21]. SSM can independently adjust three important process parameters: the substrate temperature, the temperature difference between the substrate and the source-wafer, and the temperature of the material source providing the atmosphere within the reaction tube; the most important feature is the short distance between the source and the wafer. As a result, it is a method for controlling the elemental transfer mechanism from the source wafer to the substrate. In particular, polymorphic SiC crystals such as 6H, 4H, and 3C could be grown using this method [22-24]. Meanwhile, this method was utilized to grow epitaxial layers applicable as devices on heterogeneous substrates. In the case of GaN epitaxial layers, the lattice mismatch with sapphire substrates is generally about 14%, while the lattice mismatch with 6H-SiC substrates is very small at 3.5%. Therefore, growing GaN epitaxial layers using 6H-SiC substrates, even though they are heterogeneous substrates, is attracting attention for its applicability, and high-quality GaN epitaxial layers could be grown using the SSM method [25-28]. Meanwhile, AlN is a direct transition semiconductor with a wide bandgap of 6.2 eV and is very important as a base material for UV LEDs or detectors that can be utilized for medical or environmental applications.In addition, due to its excellent electrical and thermal properties, it is possible to apply it to high-power, high-frequency electronic devices, and thus much research is being conducted on AlN substrate fabrication and single-crystal growth [29-31]. For bulk AlN crystals, the best growth method is by sublimation. However, using SSM, high-quality AlN epitaxial layers with significantly improved surface morphology and crystal quality can be grown on SiC substrates via the metal organic chemical vapor deposition (MOCVD) method [32-35]. As such, SSM has many advantages for growing epitaxial layers on heterogeneous substrates.

[0004] However, since this SSM feeds the raw material all at once before the growth process, it is not possible to continuously supply the raw material, so only AlN bulk growth below a certain size is possible. In addition, there is a disadvantage that expensive equipment and facilities are required because the growth temperature is high, ranging from 1700 to 2300 degrees.

[0005] Meanwhile, the combination of Si and SiC has many potential applications in the fields of electronics and optoelectronics. Therefore, growing high-quality Si epitaxial layers on SiC substrates can be a very important technology due to the combination of Si technology and SiC, a wide bandgap material [36-42]. However, since the degree of lattice mismatch between Si and 4H-SiC is about 20%, growing high-quality crystalline Si epitaxial layers on SiC is an important problem that must be solved [43-47].

[0006] Hydrogen vapor phase epitaxy (HVPE) has a faster growth rate compared to metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), making it advantageous for growing thick films ranging from tens to hundreds of micrometers. With the ability to control the growth rate along with the rapid growth rate, research on the growth of multilayer structures using HVPE is also being conducted

[48] . HVPE equipment is broadly divided into a source zone, a reaction zone, and a growth zone. In the source zone, a boat (crucible) containing a group 3 metal is located, and HCl gas flows over the metal material to create a gaseous metal chloride. To supply the group 5 element N, NH3 gas is generally flowed to react with the metal chloride gas. As the carrier gas for the atmosphere gas and chemical reaction gases inside the reaction tube, N2, H2, or Ar, which have low reactivity, are generally selected and used [49-51].

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[0060] The objective of the present invention is to provide an apparatus and method for growing a semiconductor crystal thin film selected from the group including silicon and nitride semiconductors, which can be grown at low cost and low temperature by solving the problems of the conventional SSM method.

[0061] Another objective of the present invention is to provide a growth apparatus and method capable of growing a large-area semiconductor crystal thin film by recrystallization of the thin film. Such recrystallization is distinct from a heat treatment process.

[0062] Another objective of the present invention is to provide a semiconductor crystal thin film growth apparatus and method capable of growing a Si crystal thin film on a SiC substrate regardless of the size or type of the substrate.

[0063] Another objective of the present invention is to provide an apparatus and method for growing an AlN single crystal or an AlN polycrystalline layer on a polycrystalline AlN substrate. means of solving the problem

[0064] In this invention, the HVPE method is improved by placing a mixture of metals to be grown as a mixed raw material in the raw material mounting section of a reaction boat, and by vertically separating the raw material mounting section and the crystal growth section to create the same temperature range, all raw materials react simultaneously with HCl to induce the growth of a semiconductor thin film layer. Furthermore, to prevent damage to the amorphous thin film layer formed by sputtering the target material onto the substrate due to high temperature and halogenation reaction gas (HCl), two substrates having formed amorphous thin film layers are placed in contact, thereby increasing the saturation rate within the growth space to a supersaturated state and causing the amorphous thin film layer to recrystallize. Accordingly, according to this invention, silicon and nitride semiconductor crystal thin films can be grown on heterogeneous substrates.

[0065] The present invention relates to a technology that allows for the growth of various crystals regardless of the properties of the substrate by making the saturation within the growth device a supersaturated state, unlike the technology applied by Tairov et al. in 1978 to the SiC bulk growth process, which controls the saturation within the growth device to supersaturated, oversaturated, and saturated states to grow crystals that retain the properties (superstructure) of the substrate.

[0066] To achieve the above-mentioned purpose and other purposes, a semiconductor crystal thin film growth apparatus comprising silicon and nitride semiconductors according to one feature of the present invention comprises: a reaction tube; a reaction boat disposed within the reaction tube; a halogenation reaction gas supply pipe for supplying a halogenation reaction gas to the reaction boat; a nitridation reaction gas supply pipe for supplying a nitridation reaction gas to the reaction boat; and a heating unit for heating the reaction tube.

[0067] The reaction boat comprises a raw material mounting section in which a mixed raw material comprising solid aluminum and gallium is mounted; and a crystal growth section disposed above or below the raw material mounting section in which a substrate set is disposed. The crystal growth section includes at least one substrate mounting chamber. At this time, the raw material mounting section and the crystal growth section are in communication with each other through at least one through hole. The mixed raw material may further include silicon. Preferably, a ledge of a predetermined height is formed in the through hole toward the raw material mounting section.

[0068] A substrate set is formed by stacking two substrates, wherein a target crystal material is deposited as an amorphous thin film on each substrate, and the amorphous thin film surfaces of each substrate are arranged to face each other to form a substrate set.

[0069] The crystal growth unit comprises an upper substrate mounting chamber positioned above the raw material mounting unit; and / or a lower substrate mounting chamber positioned below the raw material mounting unit. Multiple upper substrate mounting chambers or lower substrate mounting chambers may be formed in the crystal growth unit.

[0070] A plurality of spacers are disposed between two substrates of a substrate set, and the spacers may be selected from the group including graphite, Al ceramic, and quartz. The diameter or thickness of the spacers is preferably sub-micro (< 1 μm), and the spacers may be placed at any position between the two substrates.

[0071] Each substrate of the substrate set is selected from the group including SiC substrates, Si substrates, sapphire substrates, and AlN substrates.

[0072] The semiconductor thin film is selected from the group including Si crystal thin films, GaN crystal thin films, and AlN crystal thin films.

[0073] The target crystal material of each substrate in the substrate set consists of nitrides including Si, GaN, and AlN.

[0074] The mixing ratio of silicon:aluminum:gallium in the mixed raw materials is 1:0~1:0.1~0.5.

[0075] According to another feature of the present invention, a method for growing a semiconductor crystal thin film containing silicon comprises the steps of: preparing a set of substrates such that two substrates, on which silicon has been deposited as an amorphous thin film, are brought into contact so that the amorphous thin films face each other, thereby forming a fine gap between the two substrates; placing a raw material mounting portion equipped with a mixed raw material comprising silicon, aluminum, and gallium inside a reaction tube; placing the set of substrates in a crystal growth portion formed vertically above or below the raw material mounting portion and communicating with the raw material mounting portion through a through hole; heating the reaction tube to a temperature in the range of 1200-1250°C; supplying a halogenation reaction gas and a nitride reaction gas to the mixed raw material; reacting the mixed raw material with the halogenation reaction gas to produce trichlorosilane gas and metal chloride gas; flowing the generated trichlorosilane gas, metal chloride gas, and nitride reaction gas into the raw material mounting portion; and introducing the chlorosilane gas into the crystal growth portion through the through hole. The method comprises the steps of: supplying trichlorosilane gas into the fine gaps of the substrate set so as to supersaturate it according to the weight of the substrates of the substrate set; and the supplied trichlorosilane gas diffusing into the interior of the amorphous thin film and recrystallizing the amorphous thin film.

[0076] According to another feature of the present invention, a method for growing a semiconductor crystal thin film including a nitride semiconductor comprises the steps of: preparing a set of substrates such that a fine gap is formed between two substrates by bringing the amorphous thin films of the target crystal material, on which the target crystal material has been deposited as an amorphous thin film, into contact so that the amorphous thin films face each other; placing a raw material mounting part equipped with a mixed raw material including aluminum and gallium inside a reaction tube; placing the set of substrates in a crystal growth part formed vertically above or below the raw material mounting part and communicating with the raw material mounting part through a through hole; heating the reaction tube to a temperature in the range of 1200-1300°C; supplying a halogenation reaction gas and a nitride reaction gas to the mixed raw material; reacting the mixed raw material with the halogenation reaction gas to produce aluminum chloride gas (AlCl) and gallium trichloride (GaCl3) gas; flowing the aluminum chloride gas, gallium trichloride gas, and nitride reaction gas into the raw material mounting part; and introducing the aluminum chloride gas into the crystal growth part through the through hole. The method comprises the steps of: supplying aluminum chloride gas into the micro-gap of the substrate set so that the aluminum chloride gas becomes supersaturated according to the weight of the substrate of the substrate set; and the supplied aluminum chloride gas diffusing into the interior of the amorphous thin film and recrystallizing the amorphous thin film.

[0077] At this time, the recrystallization step includes: a step in which the saturation at the edge of the substrate set decreases as recrystallization growth occurs while diffusing into the interface of the fine gap from a supersaturated state to a saturated state; and a recrystallization step in which a semiconductor crystal is grown according to the crystal structure of the crystal nucleus grown on the substrate.

[0078] Each substrate of the substrate set can be selected from a group including SiC substrates, Si substrates, sapphire substrates, and AlN substrates, and a plurality of spacers can be placed between two substrates of the substrate set.

[0079] Meanwhile, the target material can be AlN.

[0080] When growing a Si crystal thin film, the heating unit heats the reaction tube to a temperature range of 1200-1250°C, and the mixing ratio of silicon:aluminum:gallium of the mixed raw materials is preferably 1:0 to 1:0.1 to 0.5 for the Si crystal thin film. The deposition thickness of the amorphous silicon is in the range of 100 to 200 nm.

[0081] When growing AlN single crystals / polycrystalline materials, the heating unit heats the reaction tube to a temperature range of 1200-1300℃, and it is preferable that the mixing ratio of aluminum to gallium of the mixed raw materials be 1:0.1 to 0.5. Effects of the invention

[0082] According to the semiconductor crystal thin film growth apparatus and method of the present invention, large-area crystal thin films can be grown on various substrates using the HVPE method, which utilizes a mixed raw material composed of silicon, aluminum, and gallium, regardless of the properties (single-crystal substrate, polycrystalline substrate, amorphous substrate, etc.) or size of the substrate. The recrystallization of such thin films is different from a simple heat treatment process.

[0083] In addition, according to the present invention, two substrates on which an amorphous thin film of any thickness is deposited are brought into contact so that the amorphous thin films face each other. At this time, the pressure of contact between the two substrates depends on the weight of the upper substrate, and a fine gap between the two substrates is formed by contact due to the weight of the upper substrate. As a constant pressure of approximately the weight of the upper substrate is applied in a narrow growth region within the fine gap, the supplied source gas forms a supersaturated state, and as the source gas diffuses toward the center, the material of the previously deposited thin film undergoes a recrystallization process together with the supplied source, thereby enabling the formation of a large-area crystalline thin film of Si or a nitride semiconductor (including AlN).

[0084] Accordingly, according to the present invention, the size of the substrate of the crystalline thin film is not limited, and recrystallization is possible by depositing an amorphous thin film layer of various raw materials. In addition, the deposition equipment is not limited to a sputtering device.

[0085] In addition, it provides a Si thin film layer that is much less expensive than conventional growth methods and can be used in various applications, thereby improving economic efficiency.

[0086] The Si crystal thin film grown according to the present invention can activate fields related to the silicon industry, such as solar cells, secondary batteries, power semiconductors, and optoelectronic devices, as well as a new industrial and technological field called monolithic silicon photonics OEIC (optoelectronic integrated circuit) in which optoelectronic devices and electronic devices are simultaneously integrated. In addition, direct transition light emission is possible, so it can be applied as a light-emitting device such as LEDs and LDs, and as a light-receiving device such as a photodiode.

[0087] Due to the theoretically high-pressure growth conditions required for these large-area Si crystal thin films, the possible size of hexagonal crystals is limited to the nanoscale, making it difficult for many researchers to conduct direct experimental studies. Consequently, over the past few decades, theoretical considerations such as density functional theory and structural energy band theory have been explored, along with investigations into the physical properties of nanoscale materials. Therefore, elucidating the impact of nanomaterials on general crystal growth to propose new growth methods is crucial for Si thin film crystal growth, which is essential for technological independence and securing a leading position in related fields for various applications across a broad wavelength range. Furthermore, two-dimensional single-crystal / polycrystalline AlN thin film layers provide substrates capable of growing layers such as GaN, thereby enabling cost reduction in applications like power semiconductors and optoelectronic devices. Brief explanation of the drawing

[0088] FIG. 1 is a drawing illustrating a semiconductor crystal growth apparatus according to one embodiment of the present invention. FIGS. 2a to 2d are drawings illustrating embodiments of a reaction boat (200). Figures 3a and 3b are drawings illustrating a set of substrates. FIGS. 4a to 4g are schematic diagrams illustrating the semiconductor crystal growth method of the present invention. FIG. 5 is an optical image of a set of substrates after a silicon semiconductor crystal thin film has been grown according to one embodiment of the present invention. FIG. 6 is an optical image showing a silicon crystal thin film after separating two substrates of a substrate set after the silicon semiconductor crystal thin film of the present invention has grown. Figure 7 is an optical image of a substrate on which an amorphous silicon thin film layer formed by sputtering deposition is formed prior to the growth of a semiconductor crystal thin film. Figure 8 is an FE-SEM image of the edge portion of the grown Si crystal thin film. Figure 9 is an FE-SEM image of the “A” portion of Figure 8, enlarged. Figure 10 is an FE-SEM image of the “B” portion of Figure 8, enlarged. Figure 11 is an FE-SEM image of the “C” portion of Figure 10, enlarged. Figure 12 is a cross-sectional FE-SEM image of section "D" in Figure 8. Figure 13 is an enlarged FE-SEM image of Figure 12. Figures 14a and 14b are FE-SEM and EDS measurement results that can confirm the characteristics of a sputtered amorphous Si thin film. Figures 15a and 15b are FE-SEM and EDS measurement results of a cross-section of a Si sample sputtered and deposited for 20 minutes. Figures 16a to 16c are FE-SEM results of the actual measurement of the process of changing into a Si thin film layer. Figures 17a to 17c are FE-SEM results at a position approximately 250 μm away from the edge toward the center. Figures 18a to 18c are FE-SEM results at a position approximately 500 μm away from the edge toward the center. Figures 19a to 19c are FE-SEM results at a position approximately 1000 μm away from the edge toward the center. Figures 20a to 20c are FE-SEM results near the center. Figures 21a to 21d are SIMS analysis results according to depth of a Si crystal thin film grown according to an experimental example of the present invention. FIGS. 22a to 22d are XPS results of Si crystal thin films grown according to experimental examples of the present invention. Figures 23a to 23c are XRD 2theta / omega results of Si crystal thin film samples with 2θ values ​​measured in the range of 20° to 120°. FIG. 24 is a cross-sectional transmission electron microscope (TEM) image of a silicon crystal thin film layer in a silicon crystal thin film grown on a SiC substrate according to one experimental example of the present invention. Figure 25 shows the GIXRD (the grazing incidence XRD) measurement results of the silicon crystal thin film layer in a silicon crystal thin film grown on a SiC substrate according to one experimental example of the present invention. FIGS. 26a to 26c are FE-SEM images of an AlN polycrystalline thin film grown on a polycrystalline AlN substrate according to one experimental example of the present invention. Figures 27a and 27b are the EDS results of the sample in Figure 26. Specific details for implementing the invention

[0089] The present invention is described below in detail with reference to the attached drawings so that those skilled in the art can easily implement it. In the drawings, elements indicated by the same reference numerals indicate the same elements.

[0090] FIG. 1 is a schematic diagram of a semiconductor crystal thin film growth apparatus according to one embodiment of the present invention. Referring to FIG. 1, the semiconductor crystal thin film growth apparatus comprises a reaction tube (100), a reaction boat (200) disposed within the reaction tube (100), a gas supply unit (300) that supplies various reaction gases within the reaction tube (100), and a heating unit (400) that heats the inside of the reaction tube (100).

[0091] It is preferable to use a quartz tube for the reaction tube (100). It is preferable to use a hot wall furnace consisting of three general heater furnaces for the heating unit (400), but it is not limited thereto and an RF furnace may be used. The heating unit (400) heats the reaction tube (100) to a temperature range of 1200-1300°C. In particular, it is preferable to heat to a temperature range of 1200-1250°C for Si crystal thin film growth and to heat to a temperature range of 1200-1300°C for AlN single crystal / polycrystalline thin film growth.

[0092] The reaction boat (200) is composed of a multilayer structure in which a raw material mounting section (210) in which mixed raw materials are placed and a crystal growth section (220) in which a substrate is placed are arranged vertically. It is preferable to cover the upper part of the reaction boat (200) with a cover (290). A lower through hole (250) is formed in the center of the bottom surface of the raw material mounting section (210) so that reaction gases can flow to the crystal growth section (220). Although FIG. 1 shows one through hole (250) formed in the center of the bottom surface, it is not limited thereto and two or more holes may be dispersed therein. Preferably, a ledge (212) of a predetermined height is formed in the through hole (250) toward the raw material mounting section (210), so as to prevent the mixed raw materials in the raw material mounting section (210) from melting and flowing to the crystal growth section (220) and to increase the pressure when reaction gases flow toward the crystal growth section (220) toward the substrate set (500).

[0093] Additionally, the raw material mounting part (210), the crystal growth part (220), and the cover (290) can be joined using graphite screws (not shown).

[0094] The mixed raw material (211) placed in the raw material mounting part (210) is a mixture of solid aluminum and gallium. When growing a silicon crystal thin film, a mixture of solid silicon, aluminum, and gallium is placed.

[0095] A substrate set (500) is placed in the crystal growth section (220). The substrate set (500) is formed by stacking two substrates (510, 520), wherein the material of the target crystal is deposited as an amorphous thin film (511, 521 in FIG. 3a-b) on each substrate (510, 520), and the amorphous thin films of each substrate are arranged to face each other to form a set.

[0096] Referring to FIG. 3a, the upper substrate (510) and the lower substrate (520) of the substrate set (500) are stacked and come into contact with each other due to the weight of the upper substrate (510). However, since no separate fastening means or pressure is applied to bring the upper substrate (510) and the lower substrate (520) into contact, a small gap (d) is created between the two substrates.

[0097] Alternatively, as shown in FIG. 3b, the fine gap between the two substrates (510, 520) can be controlled by a spacer (530). The spacer is also called a gap material and can be in the form of a sphere or a rod, and it is preferable to select one of graphite, Al ceramic, or quartz as the material. The spacer is similar to the spacer used in the manufacture of LCDs, for example, and can act as a pillar that maintains a constant gap between the two substrates by randomly dispersing it at an arbitrary location rather than at a fixed position between the two substrates (510, 520) to maintain the gap between the two substrates (510, 520).

[0098] In particular, referring to FIG. 3a, a substrate set (500) used when growing a semiconductor crystal thin film into a silicon crystal thin film is described. The substrate set (500) consists of two substrates (510, 520) on which an amorphous silicon layer (511, 521) is deposited on SiC substrates (510, 520), arranged so that the amorphous silicon layers (511, 521) face each other. At this time, the amorphous silicon layer (511, 521) is formed by sputtering silicon of 100 to 200 nm onto each SiC substrate, but is not limited thereto. In one experimental example, the SiC substrate on which silicon is deposited has Ar 10 sccm and a pressure of 6 x 10 -2It was prepared by sputtering for 20 minutes under conditions of RF power of 48W at torr. In the drawing, the gap (d) between the substrates is the gap between facing substrates, and is a gap that includes the thickness of the amorphous silicon layer (511, 521). This is because the deposited amorphous silicon layer (511, 521) itself recrystallizes, so the thickness of the amorphous silicon layer is included in the gap (d) between the substrates. In one experimental example, the fine gap (d) between the two substrates is related to the thickness of the deposited amorphous silicon layer, and when deposited to about 1300 Å each as an example, d becomes approximately 2600 Å when there is no spacer.

[0099] In addition, since it is desirable for the crystal growth section (220) to maximize the internal pressure when reaction gases are introduced, it is desirable to minimize the internal volume of the crystal growth section (220).

[0100] FIGS. 2a to 2c are drawings showing various embodiments in which a crystal growth section (220) is formed in a reaction boat (200).

[0101] FIG. 2a is an embodiment in which a lower substrate mounting chamber (221) is positioned vertically below the raw material mounting section (210) as in FIG. 1. The raw material mounting section (210) and the lower substrate mounting chamber (221) are connected by a lower through hole (250), and a ledge (212) is formed in the lower through hole (250).

[0102] FIG. 2b is an embodiment in which an upper substrate mounting chamber (222) is positioned vertically above the raw material mounting section (210). A through hole (260) is formed in the bottom surface of the upper substrate mounting chamber (222) to allow raw material gas and reaction gas to flow, and a substrate set (500) is positioned in the upper substrate mounting chamber (222). At this time, the substrate set (500) may be positioned at a predetermined height away from the through hole (260) so that it does not block the through hole (260).

[0103] The reaction boat (200) of FIG. 2c is an embodiment in which a lower substrate mounting chamber (221) and an upper substrate mounting chamber (222) are respectively arranged vertically below and above the raw material mounting section (210). The reaction boat (200) of FIG. 2d is an embodiment in which the reaction boat of FIG. 2c is extended sideways to form multiple lower substrate mounting chambers (221) and upper substrate mounting chambers (222). Using the reaction boat (200) of FIG. 2d allows for the formation of semiconductor crystal thin films on multiple substrate sets in a single growth process. That is, the reaction boat (200) places substrate sets (500) in each substrate mounting chamber (221, 222) of a crystal growth section (220), which is a separate space where raw material gas and reaction gas flow downward or upward through through holes (250, 260) vertically above or below the raw material mounting section (210), centered on the raw material mounting section (210) where mixed raw materials are mounted on the bottom surface. Accordingly, the raw material mounting section (210) and the crystal growth section (220) have a configuration in which they are arranged vertically. The HVPE method using mixed raw materials as in the present invention is a method of growing crystals by mixing all metal raw materials in the raw material mounting section of a single reaction boat (200) [49-51].

[0104] The mixed raw material placed in the raw material mounting part (210) includes aluminum and gallium. When forming a silicon crystal thin film, silicon is additionally included, and the mixing ratio of silicon:aluminum:gallium is preferably 1:0 to 1:0.1 to 0.5. The Si raw material can be used by cutting an n-type Si substrate into small pieces.

[0105] When growing AlN single crystal / polycrystalline thin films, only aluminum and gallium are mixed without silicon and used as mixed raw materials, and it is preferable that the mixing ratio of aluminum to gallium be 1:0.1 to 0.5.

[0106] Among the mixed raw materials, Ga (7N) melts at low temperatures and adsorbs onto the surfaces of metallic Al and Si, allowing them to react well with HCl. Metallic Al (4N) plays an important role in adsorbing Si elements through the synthesis of nanostructures in the form of initial AlN

[52] .

[0107] Since the crystal growth section (220) is positioned vertically above or below the raw material mounting section (210), the raw material mounting section (210) and the crystal growth section (220) can have the same temperature gradient, and by having the same temperature gradient, the pressure of the gas entering the crystal growth section (220) can be increased. In addition, it is desirable to minimize the internal volume of the crystal growth section (220) in order to maximize the pressure inside the crystal growth section (220), and it is desirable to form the height as small as possible in order to minimize the internal volume of the crystal growth section (220). In addition, the raw material mounting section (210), the crystal growth section (220), and the cover (290) can be joined using a graphite screw (not shown), and the internal pressure of the crystal growth section (220) thus joined can be maintained at a constant pressure value, preferably in the range of 0.1-0.16 GPa.

[0108] The gas supply unit (300) comprises an atmosphere gas supply unit (310) that supplies an atmosphere gas such as nitrogen, a nitrification reaction gas supply unit (320) that supplies a nitrification reaction gas such as ammonia (NH3), and a halogenation reaction gas supply unit (330) that supplies a halogenation reaction gas such as hydrogen chloride (HCl), and each gas supply unit supplies gas to the reaction tube (100) through supply pipes (311, 321, 331). The nitrification reaction gas supply pipe (321) that supplies the nitrification reaction gas is preferably formed of a quartz tube.

[0109] The atmosphere gas supply unit (310) can create a nitrogen atmosphere inside the reaction tube (100) and the reaction boat (200) by supplying an atmosphere gas, for example, nitrogen, through the atmosphere gas supply pipe (311). Although the atmosphere gas supply pipe (311) is shown as being outside the reaction boat (200) in FIG. 1, the atmosphere gas can be supplied directly inside the reaction boat (200) as needed.

[0110] The nitriding reaction gas supply pipe (321) connected to the nitriding reaction gas supply unit (320) flows into the raw material mounting unit (210) and supplies nitriding reaction gas to the crystal growth unit (220) through the through hole (250). Accordingly, it is most preferable for the outlet of the nitriding reaction gas supply pipe (321) to pass through the side wall of the reaction boat (200) as shown in FIG. 1 and be placed in the raw material mounting unit (210), but it is not limited thereto, and it may be placed in a position where the nitriding reaction gas can flow smoothly.

[0111] The halogenation reaction gas supply pipe (331) connected to the halogenation reaction gas supply unit (330) flows into the raw material mounting unit (210) and supplies halogenation reaction gas to the raw material mounting unit (210). It is most preferable that the outlet of the halogenation reaction gas supply pipe (331) passes through the side wall of the reaction boat (200) as shown in FIG. 1 and is positioned in the raw material mounting unit (210), but it is not limited thereto.

[0112] A method for growing a semiconductor crystal thin film using a semiconductor crystal thin film growth apparatus according to the present invention is described.

[0113] First, a mixed raw material consisting of solid aluminum and gallium is evenly distributed in the raw material mounting section (210) of the reaction boat (200).

[0114] Next, a method for growing a semiconductor crystal thin film according to the present invention will be described.

[0116] 1. When growing a Si crystal thin film,

[0117] First, we will explain the case of growing a silicon crystal thin film.

[0118] When growing a silicon crystal thin film, a mixed raw material comprising silicon, aluminum, and gallium is prepared. For the Si crystal thin film, the mixing ratio of silicon:aluminum:gallium in the mixed raw material is preferably 1:0 to 1:0.1 to 0.5.

[0119] Next, a substrate set (500) is placed in the crystal growth section (220). When growing a silicon crystal thin film, the substrate set (500) is placed in the crystal growth section (220) such that the amorphous Si layers face each other and come into contact after sputtering amorphous Si to a thickness of 100 to 200 nm onto a SiC substrate. At this time, a plurality of spacers may be used between the two SiC substrates.

[0120] Next, nitrogen, which is an atmosphere gas, is supplied, and the heating unit (400) is operated to heat the reaction tube (100) to 1200-1250°C, while supplying the halogenation reaction gas (HCl) from the halogenation reaction gas supply unit (330) and the nitrification reaction gas (NH3) from the nitrification reaction gas supply unit (320) to the reaction boat (200). In one experimental example, HCl, NH3, and N2 gases were supplied at constant rates of 200 scum, 500 sccm, and 500 sccm, respectively, along the outlets of the respective gas supply tubes.

[0121] At this time, the mixed raw material and the halogenated reaction gas react to produce trichlorosilane gas and metal chloride gas, and the produced trichlorosilane gas (SiCl3) and metal chloride gas (AlCl, GaCl3) and the nitriding reaction gas are introduced into the crystal growth section (220) in which the substrate set (500) is placed through the through hole. The introduced trichlorosilane gas is supplied into the fine gap between the substrates (510, 520) of the substrate set (500) to a supersaturated state.

[0122] The amorphous Si thin film layer deposited on the substrate (510, 520) diffuses inward and recrystallizes due to the trichlorosilane gas supplied through the fine gaps of the substrate set (500). At this time, the AlN nanostructure plays a role in promoting the recrystallization process.

[0123] Specifically, numerous Al-based nanostructures are formed at the edges of the amorphous Si thin film layer deposited by sputtering. At a growth temperature of 1200-1250°C, crystal nuclei are generated at the grain boundaries of the amorphous Si thin film layer under the influence of HCl, NH3, AlCl, GaCl3, and SiCl3, thereby growing HVPE Si crystals and recrystallizing the amorphous Si thin film layer into a Si crystal thin film. Gas flow is induced between the contact surfaces of the substrates (510, 520) to form a supersaturated state of these gases, thereby causing the amorphous Si thin film layer to undergo a recrystallization process in which the original amorphous structure is completely decomposed and new crystals are formed again by the injected gases.

[0124] In one experimental example, the growth temperature was 1250℃ and the growth time was 100 minutes.

[0125] The final thickness range of the Si crystal thin film is approximately 30% smaller than the thickness of the amorphous Si thin film layer deposited by sputtering. That is, if the thickness of the amorphous Si thin film layer is 1300 Å to 2600 Å, the range becomes 900 Å to 1000 Å, which is a 30% reduction compared to this, and this appears to be due to the thickness decreasing as recrystallization occurs.

[0126] With reference to FIGS. 4a to 4g, the process of growing a Si crystal thin film according to the present invention is schematically explained. The thickness of a single SiC substrate is 350 μm and the density is 3.2 g / cm³. 3Therefore, the weight of a 150 x 150 mm substrate is approximately 245 dyn. Assuming the surfaces of the two substrates are mirror surfaces, the gap between the two substrates is defined by the thickness of the sputtered amorphous Si thin film layer, and numerous Al nanostructures are formed on the edges of the sputtered amorphous Si thin film. Fig. 4a schematically illustrates the amorphous Si thin film deposited by sputtering on two SiC substrates. In Fig. 4b, the sputtered Si thin film is approximately 100 nm to 200 nm thick. Fig. 4c illustrates an embodiment of the present invention, a process of stacking two SiC substrates so that the sputtered amorphous Si thin film layers face each other; the two substrates come into contact due to the weight of the substrates according to their size, forming a sandwich structure as shown in Fig. 4d. The gap between the two substrates is defined by the thickness of the Si thin film deposited by sputtering, and in this case, the supersaturation phenomenon, which is a very important phenomenon in growth and has been widely confirmed to be effective for high-quality crystal growth in the growth of various crystals, is at play [85-95]. Fig. 4e is an enlarged cross-sectional view of section "B" in Fig. 4d, and in particular, in the case of supersaturation, the dependence on the substrate is very low, so crystallinity can be formed on various substrates. As a result, as shown in Fig. 4f, internal stress of the amorphous Si thin film deposited by sputtering is removed, and new crystal nuclei are generated at the crystal boundaries due to the influence of HCl, NH3, AlCl, GaCl3, and SiCl3, and HVPE Si crystals grow, converting the amorphous Si deposited by sputtering into Si crystals. That is, the amorphous Si thin film deposited by sputtering recrystallizes to become a silicon crystal thin film. In particular, Fig. 4f is an actual photograph of an embodiment of the present invention in which a crystallized thin film layer exists alone without a SiC substrate underneath during cleaving, and the crystalline state is clear.

[0127] In the present invention, it is believed that the AlN nanostructure plays a major role in this recrystallization

[52] . The recrystallization process at the surface is schematically illustrated in Fig. 4g. As shown in Figs. 4e and 4g, AlN nanostructures are dominant at the edges, and as they approach the center, the grain size increases and reaches an equilibrium state of a certain size, at which point the grains merge with each other as shown in Fig. 4f.

[0128] Figure 4f is an actual FE-SEM result showing that an amorphous Si thin film layer deposited by sputtering on two SiC substrates according to an embodiment of the present invention has recrystallized into silicon crystals. The crystalline state is clearly visible in the actual photograph showing the crystallized silicon crystal thin film existing alone without the SiC substrate underneath during cleaving.

[0129] FIG. 4g schematically illustrates the process of recrystallization in a saturated atmosphere through a diffusion process in a supersaturated state of a Si thin film deposited by sputtering on two SiC substrates using an improved HVPE sublimation sandwich apparatus as an embodiment of the present invention.

[0130] The results of growing a Si crystal thin film under the experimental conditions of Table 1 are explained as follows.

[0131] condition experiment Reaction tube temperature 1200-1250℃ 1250℃ hydrogen chloride 20~1000 sccm 500 sccm Growth time 2 minutes to 2 hours 100 minutes Amount of silicon in mixed raw materials Si: 10~100g 30g Amount of aluminum in mixed raw materials 0~50g 20g Amount of gallium in the mixed raw materials 1~20g or less 10g Si sputtering 6 nm / min 20 minutes Si crystal growth rate 1.5 nm / min 140 nm ammonia 500-5000 sccm 500 sccm nitrogen 500-5000 sccm 500 sccm spacers 1 mm or less 0

[0132] First, a SiC substrate was used to form a 120 nm amorphous silicon layer by depositing silicon on a SiC substrate at a sputtering deposition rate of 6 nm / min for 20 minutes. The size of the substrate is determined by the size of the substrate that can be deposited in the sputtering device.

[0133] During the crystal growth stage, hydrogen chloride, ammonia, and nitrogen gases were supplied at constant rates of 500 sccm, 500 sccm, and 500 sccm, respectively. The growth temperature was set to 1250℃ and the growth time to 100 minutes. For the Si epitaxial layer, 30g of Si, 20g of Al, and 10g of Ga were used as the mixed raw materials. In this case, the Si thin film layer exhibits amorphous properties.

[0134] Figure 5 is an optical image of a set of substrates after the growth of a silicon semiconductor crystal thin film. The two substrates in the set of substrates have such strong adhesion that they can only be separated by applying mechanical force. Figure 6 is an optical image showing the silicon crystal thin film after the two substrates in the set of substrates in Figure 5 have been separated from each other. Figure 7 is an optical image of a substrate on which an amorphous silicon thin film layer formed by sputtering deposition is formed before the growth of the semiconductor crystal thin film. The amorphous silicon thin film layer was deposited at a deposition rate of 7 nm / min for 20 minutes, and the image was taken with a thickness of approximately 140 nm, which contrasts with Figure 6.

[0135] Figure 8 is an FE-SEM image of the edge portion of the grown Si crystal thin film. Differences in the surface are observed in regions “A” and “B”. Figure 9 is an enlarged view of region “A” in Figure 8, showing nanostructures. Figure 11, which is a further enlarged view, is a cross-sectional FE-SEM result of region “C” in Figure 10, clearly showing nanostructures with lengths of tens of μm and a crystal thin film thickness of 127 nm.

[0136] Figure 10 is an enlarged view of section “B” of Figure 8, showing that a silicon crystal thin film is formed on a SiC substrate. Figure 12 is a cross-sectional FE-SEM image of section “D” of Figure 8, showing the cross-section of the portion where the silicon crystal thin film layer is formed. Recently, Si nanocrystals (Si NCs) have attracted attention for the manufacture of next-generation solar cells because their bandgap can be adjusted by quantum size effects [53-55]. These films are formed using deposition techniques such as sputtering, and a form having nanocrystals of about 2–5 nm is obtained through heating at high temperatures (1000°C–1100°C) [56-58]. This phenomenon in thin films can be explained by recrystallization, which is a growth process in which new crystals are generated on the substrate and grow through a supplied source, changing the entire structure into a new crystal [59-62].

[0137] Figures 14a and 14b are FE-SEM and EDS measurement results that confirm the characteristics of a sputtered amorphous Si thin film. In Figure 14a, no specific particles were observed on the sputtered Si surface, confirming it to be an amorphous Si surface. The EDS measurement results in Figure 14b show that the C component ratio is 26.03 at.% and the Si elemental ratio is 73.97 at.%, indicating that the Si elemental ratio has increased due to the influence of the deposited Si layer.

[0138] Figures 15a and 15b show the FE-SEM and EDS measurement results of a cross-section of a Si sample sputtered and deposited for 20 minutes. In Figure 15a, the Si deposition rate is approximately 7 nm / min, and a thickness of 144 nm can be confirmed. In the EDS results of the deposited cross-section in Figure 15b, the deposited Si component ratio was measured to be 100 at.%.

[0139] Figures 16a to 20c are FE-SEM results of the actual measurement of the process of transformation into a Si crystal thin film.

[0140] Figures 16a to 16c show nanostructures formed at the substrate edge; Figure 16a is an FE-SEM image near the substrate edge. That is, due to low adhesion between the two substrates near the edge, HCl, AlCl, and SiCl n Nanostructures were formed under the influence of source gases. Figure 16b shows a magnified view of the substrate surface where the nanostructures were formed, revealing small particles. Figure 16c shows the particle size of each indicated area, confirming that particles with an average diameter of 24 nm were formed.

[0141] Figures 17a to 17c show the FE-SEM results at a distance of about 250 μm from the edge toward the center. In Figure 17a, a nanostructure with low density can be observed, and in Figure 17b, particles larger than those in Figure 16b can be observed, and as in Figure 17c, they are evaluated as particles with an average diameter of 30 nm.

[0142] Figures 18a to 18c show the FE-SEM results at a position approximately 500 μm away from the edge toward the center. In Figure 18a, no nanostructure shape was observed, which is a result of increased density between the two substrates compared to the edge. In Figure 18b, it can be seen that the particle shape has significantly increased, and as in Figure 18c, a surface with particles having an average diameter of 45 nm can be identified.

[0143] Figures 19a to 19c show the FE-SEM results at a distance of about 1000 μm from the edge toward the center. As shown in Figure 19b, the particle size increases and tends to stick together, and in Figure 19c, particles with an average diameter of 60 nm are observed.

[0144] Figures 20a to 20c show FE-SEM results near the center. In the experimental example of the present invention, a substrate of size 20 x 20 mm was used, with the center located about 10 mm from the edge, and Figure 20a shows a surface similar to an epitaxial layer. Figure 20b shows a surface with particle size similar to that of Figure 19b, and the average diameter is evaluated to be 62 nm.

[0145] As shown in FIGS. 16a to 20c, the surface of the silicon crystal thin film appears from about 1 mm toward the center from the edge, and as a result, silicon crystal thin film growth is possible over more than 90% of the area. This confirms that, according to the present invention, a large-area Si crystal thin film layer can be grown on a SiC substrate.

[0146] Figures 21a to 21d show the SIMS analysis results according to depth of a Si crystal thin film grown according to an experimental example of the present invention. SIMS is an analytical method capable of detecting trace elements in ppb (parts per billion) units. In the present invention, a Cs+ gun was used, with an impact energy of 5 keV (Current: 20 nA), a raster size of 200 μm × 200 μm, and an analysis area with a diameter of 60 μm. The detected ions were C+, O+, Al+, Si+, and Ga+. Figure 21a is an optical photograph showing the measurement areas at three points of a Si crystal thin film sample grown according to an experimental example of the present invention, indicating the edge, the ring (a region 8 mm away from the edge), and the center. Figure 21b shows the analysis results of the edge, where Al appears initially and is measured up to a depth of 300 nm or more. Figure 21c shows the region approximately 8 mm from the edge, where the Al content decreases rapidly. Figure 21d shows the SIMS results near the center; the depth at which the Al content decreases rapidly—specifically around 125 nm—is determined to be the thickness of the crystal thin film, which is in good agreement with the cross-sectional results of the Si crystal thin film in Figure 13. In the present invention, Al is used among the mixed raw materials to form Al-based nanostructures, and these nanostructures undergo a mechanism in which they absorb elements such as Si to form an epitaxial layer. Consequently, a large number of Al-related nanostructures are found near the edge, which is in good agreement with the SIMS results of the edge. In the case of the Si crystal thin film, it is determined that Al was included on the surface during the pre- and post-growth processes, and as can be confirmed from the SIMS results of the central part, the Si crystal thin film was grown.

[0147] Figures 22a to 22d show the XPS results of a Si crystal thin film grown according to an experimental example of the present invention. An Al K Alpha source was used for the measurement, and the spot size was 200 μm. The pass energy was 200.0 eV, and the Ar etching rate was 2 nm / sec. Figure 22a is an optical photograph of a Si crystal thin film sample grown according to an experimental example of the present invention, with the "A" portion measured. Figure 22b shows the changes in components according to depth. Initially, the Si 2p component was dominant, while the C 1s component decreased rapidly. The O 1s component reached a ratio nearly equal to the Si 2p component starting from a depth of about 30 nm. At the surface, the elemental ratio of Si 2p was 33.689 at.%, and at a depth of 500 nm, the elemental ratio of Si 2p increased to 38.683 at.%. On the other hand, the elemental ratio of C 1s was 31.113 at.%, and at a depth of 500 nm, the elemental ratio of Si 2p decreased to 22.458 at.%. The elemental ratio of O 1s was 35.197 at.%, and at a depth of 500 nm, the elemental ratio of Si 2p increased to 38.907 at.%. Assuming the thickness of the Si crystal thin film is 150 to 200 nm, a Si layer has been grown on a SiC substrate. Furthermore, this implies that the Si layer is oxidizing and transforming into a SiO2 layer. Figure 22c shows the binding energy of Si 2p on the surface of the Si crystal thin film. 103.5 eV represents the SiO2 binding energy, and 101.8 eV is determined to be the Si-C binding energy. In addition, Fig. 22d shows a Si-OC binding energy of 102.5 eV at a depth of 100 nm, and a Si-C binding energy of 101.2 eV was measured. In Fig. 22d, it can be seen by fitting the spectrum that an oxide phase related to Si was formed on the SiC surface [63-65].

[0148] Figures 23a to 23c show the XRD 2theta / omega results of Si crystal thin film samples with 2θ values ​​measured in the range of 20° to 120°. In Figure 23a, a sample with an amorphous Si layer sputtered and deposited on a SiC substrate was compared. In the case of the SiC substrate, 2θ = 35.7 and 75.3 are attributed to the (0004) and (0008) planes corresponding to 4H-SiC [66-70], and the peaks match ICSD ID 98-016-4971. Since the thickness of the amorphous Si layer is very thin and it is deposited in an amorphous form, the intensity of the Si layer is very weak, so no peaks appear on the XRD measurement graph. Figure 23b shows the XRD results of the Si crystal thin film sample. Three diffraction peaks with 2θ values ​​of 26.38°, 35.57°, and 75.33° may correspond to the (003), (004), and (222) planes of the 4H-SiC substrate, respectively [70-74]. In the region of “A” in Fig. 23b, the results of measuring 2θ values ​​in the range of 15° to 35° can be seen in Fig. 23c. A (003) SiC substrate peak with 2θ = 26.44° and a Si peak with 28.51° were measured. This can be interpreted as originating from the cubic Si (111) plane, and using the database of the Fd3m space group (The International Centre for Diffraction Data, ICDD; 03-065-1060), 28.51° is attributed to the (111) plane and 114.3° in Fig. 23b is attributed to the (531) plane; additionally, using the database of the P63 / mmc (D46h) space group (ICDD; 01-080-0005), 28.51° is attributed to the (002) plane and 114.3° in Fig. 23b is attributed to the (116) plane. 2θ = 44.73°. 54.54°, 64.52°, and 75.33° are associated with the (105), (107), (109), and (204) planes of SiC, respectively, and are related to the hexagonal structure [75-84]. And 2θ = 114.3° corresponds to the X-ray reflection of the Si (116) plane. Therefore, as a result, it can be confirmed that a crystalline Si crystal thin film has grown on SiC.

[0149] FIG. 24 is a cross-sectional transmission electron microscope (TEM) image of a silicon crystal thin film layer in a silicon crystal thin film grown on a SiC substrate according to an experimental example of the present invention. The observation of a periodic lattice shape at dotted line A in FIG. 24 clearly shows that crystallization is proceeding.

[0150] Figure 25 shows the results of the GIXRD (the grazing incidence XRD) measurement of the silicon crystal thin film layer in a silicon crystal thin film grown on a SiC substrate according to one experimental example of the present invention. The Si-related peak is a peak that appears as amorphous Si crystallizes, and the AlN-related peak confirms that AlN is contributing to recrystallization.

[0152] 2. In the case of AlN crystalline thin films

[0153] Next, AlN crystal thin film Explains the case of growing.

[0154] The mixed raw materials are prepared by mixing aluminum and gallium, and it is preferable that the mixing ratio of aluminum to gallium be 1:0.1 to 0.5. It is preferable to heat the growth temperature to a temperature range of 1200-1300℃.

[0155] A substrate set (500) is prepared by sputtering AlN onto a substrate selected from the group including a SiC substrate, a Si substrate, a sapphire substrate, and an AlN substrate to have a thickness of 1200 Å to 3600 Å. Two substrates having amorphous AlN thin films are arranged so that the amorphous AlN thin film layers face each other and come into contact. At this time, a plurality of spacers may be used between the two SiC substrates.

[0156] Next, as in the case of growing a silicon crystal thin film, nitrogen, which is an atmosphere gas, is supplied, and the heating unit (400) is operated to heat the reaction tube (100) to 1200-1300°C, while supplying a halogenation reaction gas (HCl) from the halogenation reaction gas supply unit (330) and a nitridation reaction gas (NH3) from the nitridation reaction gas supply unit (320) to the reaction boat (200). In one experimental example, HCl, NH3, and N2 gases were supplied at constant rates of 200 scum, 500 sccm, and 500 sccm, respectively, along the outlets of the respective gas supply tubes.

[0157] At this time, the mixed raw material and the halogenation reaction gas react to produce metal chloride gas (AlCl, GaCl3), and these metal chloride gas, halogenation reaction gas, and nitridation reaction gas are supplied through the through holes into the fine gaps between the substrates (510, 520) of the substrate set (500) in the substrate mounting room where the substrate set (500) is placed, resulting in a supersaturated state.

[0158] Numerous Al-based nanostructures are formed at the edges of the amorphous AlN thin film layer deposited by sputtering. At a growth temperature of 1200-1300°C, crystal nuclei are generated at the grain boundaries of the amorphous AlN thin film layer under the influence of HCl, NH3, AlCl, and GaCl3, and the amorphous AlN thin film layer recrystallizes into an AlN crystal thin film together with the new crystal nuclei. Gas flow is induced between the contact surfaces of the two substrates (510, 520) to form a supersaturated state of these gases, thereby causing the amorphous AlN thin film layer to undergo a recrystallization process in which the original amorphous structure is completely decomposed and new crystals are formed again by the injected gases.

[0159] The results of growing AlN crystal thin films under the experimental conditions of Table 2 are explained as follows.

[0160] condition experiment Reaction tube temperature 1200-1300℃ 1250℃ hydrogen chloride 20~1000 sccm 500 sccm Growth time 2 minutes to 2 hours 100 minutes Amount of aluminum in mixed raw materials 0~50g 20g Amount of gallium in the mixed raw materials 1~20g or less 10g AlN sputtering 2 nm / min 60 to 180 minutes AlN crystal thin film growth rate 0.2~0.3 μm / min 0.25 μm / min ammonia 500-5000 sccm 500 sccm nitrogen 500-5000 sccm 500 sccm spacers 1 mm or less 0

[0161] FIGS. 26a to 26c are FE-SEM images of an AlN polycrystalline thin film grown on a polycrystalline AlN substrate according to an experimental example of the present invention. FIG. 26a is a cross-sectional FE-SEM image of an AlN polycrystalline thin film grown on a polycrystalline AlN substrate according to an experimental example of the present invention, in which the distinction between the polycrystalline AlN substrate and the AlN polycrystalline thin film layer is clear. FIG. 26b is an enlarged FE-SEM cross-sectional image of FIG. 26a, and a 26 μm AlN polycrystalline thin film layer can be confirmed in FIG. 26c.

[0162] FIGS. 27a and FIGS. 27b are the EDS results of the sample of FIG. 26. FIG. 27a shows the cross-sectional EDS measurement of an AlN polycrystalline substrate, in which the elemental ratios of Al 56.66 at.% and N 43.34 at.% were measured for the polycrystalline AlN substrate. FIG. 27b shows the cross-sectional EDS measurement of a grown AlN polycrystalline thin film layer. In the case of the AlN polycrystalline thin film layer, the elemental ratios of Al 55.52 at.% and N 44.48 at.% were measured. Based on these EDS measurement results, it can be seen that AlN polycrystalline growth is possible according to the present invention.

[0163] Although the technical features of the present invention have been described above with reference to specific embodiments, it is evident that a person skilled in the art to which the present invention pertains can make various modifications and variations within the scope of the technical concept according to the present invention.

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[0214] 100: Reaction tube 200: Reaction boat 210: Raw material mounting section 211: Mixed raw material 220: Crystal Growth Division 221, 222: Board mounting room 300: Reaction gas supply unit 310: Atmosphere gas supply unit 320: Nitriding reaction gas supply unit 330: Halogenation reaction gas supply unit 400: Heating part

Claims

Claim 1 A semiconductor crystal thin film growth apparatus comprising silicon and nitride semiconductors, the apparatus comprising: a reaction tube; a reaction boat disposed within the reaction tube; a halogenation reaction gas supply pipe for supplying a halogenation reaction gas to the reaction boat; a nitridation reaction gas supply pipe for supplying a nitridation reaction gas to the reaction boat; and a heating unit for heating the reaction tube, wherein the reaction boat comprises: a raw material mounting unit in which a mixed raw material including solid aluminum and gallium is mounted; and a crystal growth unit disposed above or below the raw material mounting unit in which a substrate set is disposed, wherein the raw material mounting unit and the crystal growth unit are in communication with gas through at least one through hole, and the substrate set comprises two substrates stacked on top of each other, wherein a material of a target crystal is deposited as an amorphous thin film on each substrate, and the amorphous thin films of each substrate are disposed to face each other to form a set. Claim 2 In claim 1, the above-mentioned mixed raw material is a semiconductor crystal thin film growth apparatus further comprising silicon. Claim 3 A semiconductor crystal thin film growth apparatus according to claim 1, wherein the crystal growth unit comprises an upper substrate mounting chamber positioned above a raw material mounting unit; or a lower substrate mounting chamber positioned below a raw material mounting unit. Claim 4 In paragraph 3, the semiconductor crystal thin film growth apparatus in which the upper substrate mounting chamber or the lower substrate mounting chamber of the crystal growth section is formed in multiple numbers. Claim 5 A semiconductor crystal thin film growth apparatus according to claim 1, wherein a plurality of spacers are disposed between two substrates of the substrate set, and the spacers are selected from the group comprising graphite, Al ceramic, and quartz. Claim 6 In claim 1, each substrate of the substrate set is a semiconductor crystal thin film growth apparatus selected from the group comprising SiC substrates, Si substrates, sapphire substrates, and AlN substrates. Claim 7 In claim 1, the semiconductor crystal thin film is a semiconductor crystal thin film growth apparatus selected from the group comprising Si crystal thin film, GaN crystal thin film, and AlN crystal thin film. Claim 8 In claim 1, the semiconductor crystal thin film growth apparatus comprises a nitride including Si and GaN, and AlN, for the material of the target crystal of each substrate of the substrate set. Claim 9 A semiconductor crystal thin film growth apparatus according to claim 1, wherein the through hole has a predetermined height ledge formed toward the raw material mounting part. Claim 10 A semiconductor crystal thin film growth apparatus according to claim 1, wherein the mixing ratio of silicon:aluminum:gallium of the mixed raw materials is 1:0 to 1:0.1 to 0.

5. Claim 11 A method for growing a semiconductor crystal thin film containing silicon, comprising the steps of: preparing a set of substrates such that two substrates, each having silicon deposited as an amorphous thin film, are brought into contact so that the amorphous thin films face each other, thereby forming a fine gap between the two substrates; placing a raw material mounting section equipped with a mixed raw material comprising silicon, aluminum, and gallium inside a reaction tube; placing the set of substrates in a crystal growth section formed vertically above or below the raw material mounting section and communicating with the raw material mounting section through a through hole; heating the reaction tube to a temperature in the range of 1200-1250°C; supplying a halogenation reaction gas and a nitride reaction gas to the mixed raw material; reacting the mixed raw material with the halogenation reaction gas to produce trichlorosilane gas and metal chloride gas; and flowing the generated trichlorosilane gas, metal chloride gas, and nitride reaction gas into the raw material mounting section. A method for growing a semiconductor crystal thin film, comprising: a step of introducing trichlorosilane gas into a crystal growth section through a through hole; a step of supplying trichlorosilane gas into a fine gap of the substrate set so as to supersaturate the gas according to the weight of the substrate of the substrate set; and a step of the supplied trichlorosilane gas diffusing into the interior of the amorphous thin film and recrystallizing the amorphous thin film. Claim 12 A method for growing a semiconductor crystal thin film including a nitride semiconductor, comprising the steps of: preparing a set of substrates such that a fine gap is formed between two substrates by bringing the amorphous thin films of the target crystal material, on which the target crystal material has been deposited as an amorphous thin film, into contact so that the amorphous thin films face each other; placing a raw material mounting section equipped with a mixed raw material including aluminum and gallium inside a reaction tube; placing the set of substrates in a crystal growth section formed vertically above or below the raw material mounting section and communicating with the raw material mounting section through a through hole; heating the reaction tube to a temperature in the range of 1200-1300°C; supplying a halogenation reaction gas and a nitride reaction gas to the mixed raw material; reacting the mixed raw material with the halogenation reaction gas to produce aluminum chloride gas (AlCl) and gallium trichloride (GaCl3) gas; flowing the aluminum chloride gas, gallium trichloride gas, and nitride reaction gas into the raw material mounting section; and introducing the aluminum chloride gas into the crystal growth section through the through hole. A method for growing a semiconductor crystal thin film, comprising: a step of supplying aluminum chloride gas into a fine gap of the substrate set so as to supersaturate the aluminum chloride gas according to the weight of the substrate of the substrate set; and a step of the supplied aluminum chloride gas diffusing into the interior of the amorphous thin film and recrystallizing the amorphous thin film. Claim 13 A method for growing a semiconductor crystal thin film according to claim 11 or 12, wherein the recrystallizing step comprises: a step in which the saturation at the edge of the substrate set decreases as recrystallization growth occurs as the saturation spreads into the interface of the fine gap from a supersaturated state to a saturated state; and a recrystallization step in which a semiconductor crystal is grown according to the crystal structure of a crystal nucleus grown on the substrate. Claim 14 A semiconductor crystal thin film growth method according to claim 11 or 12, wherein each substrate of the substrate set is selected from the group comprising SiC substrates, Si substrates, sapphire substrates, and AlN substrates. Claim 15 A semiconductor crystal thin film growth method according to claim 11 or 12, wherein a plurality of spacers are disposed between two substrates of the substrate set. Claim 16 In Clause 12, the semiconductor crystal thin film growth method in which the material of the above-mentioned target determination is AlN.

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