KR102611922B1 - Apparatus and method for manufacturing hexagonal Si crystal - Google Patents

Abstract

The hexagonal silicon crystal growth apparatus of the present invention includes a reaction tube; A reaction boat placed on one side of the reaction tube; A halogenation reaction gas supply pipe that supplies halogenation reaction gas to the reaction boat; A nitriding reaction gas supply pipe that supplies nitriding reaction gas to the reaction boat; and a heating unit for heating the reaction tube, wherein the reaction boat includes a raw material loading unit having at least one through hole formed on the bottom of the cylinder and mounting a mixed raw material of solid silicon, aluminum, and gallium; and a crystal growth portion disposed below the raw material loading portion and having a concave crystal shape frame of a predetermined shape.

Description

Hexagonal silicon crystal growth apparatus and method {Apparatus and method for manufacturing hexagonal Si crystal}

The present invention relates to an apparatus and method for growing hexagonal silicon crystals, a semiconductor device using hexagonal silicon crystals, and a method for manufacturing the same, and more specifically, to growing a hexagonal silicon crystal substrate using a mixed raw material hydrogen vapor phase growth (HVPE) method. It relates to a device and method for producing a semiconductor device and a semiconductor device using a hexagonal silicon crystal.

Silicon is currently used as a very important material in major industrial fields, and has various phase structures depending on external conditions such as pressure and temperature. Research on these phases began 60 years ago, and to date, several allotropes exhibiting diverse physical properties have been reported. However, among the various allotropes, cubic silicon crystals are the most stable phase that have actually been commercialized, and bulk hexagonal silicon crystals have not been commercialized. This is because not only is it easy for silicon crystals to grow in the cubic direction, but extremely high pressure (several tens of GPa) is required to grow bulk-type hexagonal silicon crystals.

Therefore, to date, Si-related industries have relied on existing cubic silicon or amorphous silicon, and the new structures and properties of Si crystal (Si single crystal) and amorphous silicon (Si) are related to structural changes due to high temperature and pressure. In relation to this, it is the subject of much research in theory and experiment.

Meanwhile, a hexagonal diamond (Lonsdaleite) structure was recently discovered during the synthesis of Si nanowires (NWs), and in the bulk state, it was only observed under extreme pressure conditions, and pure bulk hexagonal Si crystals could not be obtained. It has been observed by several research groups that hexagonal Si crystals in the bulk form at pressures of approximately 16 GPa, while in NWs localized regions of hexagonal Si grow even under atmospheric pressure.

Recently, the results of growing a pure and stable diamond hexagonal Si shell with a thickness of 5 to 170 nm on the surface using GaP NW as a matrix were published.

Additionally, experimental results and properties of polytypes of hexagonal Si are promoting research on the material's electronic properties as well as its heat conduction properties.

The hexagonal Si structure is an independent material, and is interpreted as having different crystal phases of the same material alternating in a regular manner rather than different materials. In the case of polycrystalline Si-IV thin films, it can be obtained through a plastic deformation process using a series of laser heat treatments.

As the hexagonal nature of Si increases, the basic energy gap decreases, and Si-IV (hexagonal diamond-structured Si) is about twice as efficient as Si-I (cubic Si), and can be used directly in visible light (~1.5 eV). metastasis) can be released.

In general, Si can have polymorphs, most of which are metastable at ambient conditions. When pressure increases in Si-I (cubic diamond structure), it forms Si-II (β-Sn structure), and as pressure gradually decreases, it forms rhombohedral Si-XII (rhombohedral R8 phase) and Si-III (BC8 structure). It metastasizes. The pressure at this time is about 8 GPa to 2 GPa. The formation of Si-IV (hexagonal diamond) can be expected through continuous thermal treatment. Hexagonal Si is a crystal of Si-IV (hexagonal diamond) and has reflections parallel and perpendicular to the c-axis of the growth direction. Based on theory and experimental results, S-IV with hexagonal D46h space group structure has three Raman actives, consisting of a longitudinal optical (LO) mode with A _1g symmetry and a transverse optical (TO) mode with E _1g and E _2g symmetries. It is known to have a mode. Phonon modes can be observed in these peaks in the ranges of 518~515 cm ^-1 , 508~500 cm ^-1 , and 498~495 cm ^-1 , respectively. However, since it is practically difficult to observe A _1g , E _1g and E _2g modes at the same time, it can be confirmed that it is a hexagonal Si crystal by checking two of the three modes.

Meanwhile, the present applicant also proposed a device and method for growing needle-shaped hexagonal silicon crystals in Korean Patent No. 10-2149338 in relation to hexagonal silicon crystals, but it was not a bulk crystal.

[references]

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An object of the present invention is to provide an apparatus and method for growing hexagonal silicon crystals, and in particular, to provide an apparatus and method for growing hexagonal silicon crystals in a bulk structure.

Another object of the present invention is to provide a hexagonal silicon crystal growth device and method that has a large size (tens of mm - hundreds of mm) so that it can serve as a substrate and has a stable crystal structure at room temperature and pressure.

Another object of the present invention is to provide an apparatus and method for growing a hexagonal silicon crystal having a (002) plane.

Another object of the present invention is to provide a hexagonal silicon crystal growth apparatus and method capable of growing a hexagonal silicon crystal without a substrate or on a predetermined substrate.

Another object of the present invention is to provide a hexagonal silicon crystal growth device and method that can control the diameter, thickness, and shape of the crystal by controlling the growth rate of the hexagonal silicon crystal.

Another object of the present invention is to provide an apparatus and method that can grow bulk hexagonal silicon crystals and simultaneously grow needle-shaped hexagonal silicon crystals.

Another object of the present invention is to provide a semiconductor device using grown hexagonal silicon crystals.

In order to achieve these and other purposes, a hexagonal silicon crystal growth device according to one aspect of the present invention includes a reaction tube; A reaction boat placed on one side of the reaction tube; A halogenation reaction gas supply pipe that supplies halogenation reaction gas to the reaction boat; A nitriding reaction gas supply pipe that supplies nitriding reaction gas to the reaction boat; and a heating unit for heating the reaction tube, wherein the reaction boat includes a raw material loading unit having at least one through hole formed on the bottom of the cylinder and mounting a mixed raw material of solid silicon, aluminum, and gallium; and a crystal growth portion disposed below the raw material loading portion and having a concave crystal shape frame of a predetermined shape.

The heating unit heats the reaction tube to a temperature range of 1150-1350°C, and the mixing ratio of silicon: aluminum: gallium in the mixed raw materials is preferably 1:1 to 2:1 to 5.

In addition, the raw material loading portion and the crystal growth portion are coupled by a joint holding mechanism or are brought into close contact by the raw material loading portion's own weight, thereby controlling the pressure inside the crystal frame. Preferably, the pressure inside the crystal frame can be adjusted by temperature, the volume inside the crystal frame, and the size, mass, and volume of the raw material loading part. The pressure P inside the crystal frame is preferably 0 < P ≤ 1 GPa.

A hexagonal silicon crystal can be grown without placing a growth substrate on the crystal shape frame of the crystal growth portion, but a separation substrate may be disposed to facilitate separation of the grown hexagonal silicon crystal. The separation substrate may be selected from the group consisting of graphite, silicon carbide, silicon, sapphire, quartz, ceramic, and various commercial substrates (GaN, GaAs, InP, Ga ₂ O ₃ , etc.).

Alternatively, a-phase 4H-SiC (a = 3.0730 Å, b = 10.053 Å), 6H-SiC (a = 3.0730 Å, A SiC substrate selected from b = 10.053 Å) can be placed in a crystal mold to form a hexagonal silicon crystal on this SiC substrate.

A plurality of crystal shape frames are formed in the crystal growth portion, and the shapes or sizes of the plurality of crystal shape frames may be the same or different.

In order to grow needle-shaped hexagonal silicon crystals in addition to bulk-type hexagonal silicon crystals, a needle-shaped crystal growth part connected to the raw material loading part and the side may be further included. A growth substrate is placed in the needle-shaped crystal growth portion so that the crystal growth surface faces downward.

A hexagonal silicon crystal growth method according to another feature of the present invention includes the steps of placing a raw material loading unit equipped with a mixed raw material of solid silicon, aluminum, and gallium inside a reaction tube; Arranging a crystal growth portion in which a crystal shape frame is formed at the lower part of the raw material loading portion; Heating the reaction tube to a temperature in the range of 1150-1350°C; Supplying halogenation reaction gas and nitridation reaction gas to mixed raw materials; reacting the mixed raw materials with the halogenated reaction gas to produce trichlorosilane gas and metal chloride gas; flowing the generated silane trichloride gas, metal chloride gas, and nitriding reaction gas into the crystal growth section disposed below the raw material loading section; 3 reacting silane chloride gas, metal chloride gas, and nitriding reaction gas to generate nuclei in the crystal shape frame; and growing a hexagonal silicon crystal around the generated nucleus.

The step of growing a hexagonal silicon crystal includes replacing Si atoms with trichlorosilane gas centered on the generated nucleus; and growing a hexagonal silicon crystal by substituted Si atoms.

The generated silane trichloride gas, metal chloride gas, and nitriding reaction gas flow into the crystal growth section through at least one through hole formed on the bottom surface of the raw material loading section.

A separation substrate can be preferably placed in the crystal frame of the crystal growth portion, and the growth rate of the hexagonal silicon crystal can be adjusted by the pressure inside the crystal frame.

Alternatively, a SiC substrate is placed on the crystal shape frame of the crystal growth portion, and the SiC substrate is a-phase 4H-SiC (a = 3.0730 Å) having the following space group C46v-P63mc and hexagonal (wurtzite) crystal structure. , b = 10.053 Å,), and 6H-SiC (a = 3.0730 Å, b = 10.053 Å).

A hexagonal silicon crystal growth device according to another feature of the present invention is to place a growth substrate on the side of the raw material mounting portion with the crystal growth surface facing downward in order to grow needle-type hexagonal silicon crystals as well as bulk-type hexagonal silicon crystals. A step of arranging a substrate; further comprising allowing the generated silane trichloride gas, metal chloride gas, and nitriding reaction gas to flow toward the growth substrate on a side of the raw material mounting unit; reacting the silane trichloride gas, metal chloride gas, and nitriding reaction gas to generate nuclei in the growth substrate; And growing a hexagonal silicon crystal on a growth substrate centered on the generated nucleus.

A hexagonal silicon crystal according to another feature of the present invention is grown by the above-described hexagonal silicon crystal growth method.

A hexagonal silicon semiconductor device according to another feature of the present invention includes a first electrode formed on or connected to one side of a hexagonal silicon crystal grown by the above-described hexagonal silicon crystal growth method; and a second electrode spaced apart from the first electrode and formed on or connected to the other side of the hexagonal silicon crystal. At this time, the one side and the other side may be the same side or different sides.

Meanwhile, the hexagonal silicon semiconductor device may include a third electrode formed between the first electrode and the second electrode.

At this time, it may further include an oxide film formed between at least one of the first electrode, second electrode, or third electrode and the hexagonal silicon crystal.

According to the present invention, hexagonal silicon crystals can be grown to a desired size by the HVPE method using mixed raw materials consisting of silicon, aluminum, and gallium. The size of these hexagonal silicon crystals can be either a size that can be used as a seed (unit of mm) or a size that can be used as a substrate (tens of mm to hundreds of mm).

The hexagonal silicon crystal according to the present invention has a stable hexagonal silicon crystal structure of various sizes and shapes at room temperature and pressure.

The hexagonal silicon crystal growth apparatus and method according to the present invention can grow hexagonal silicon crystals without a growth substrate, which is essential in conventional equipment such as HVPE or MOCVD. In addition, compared to the Czochralski method or crystal pulling method, which is a conventional silicon bulk growth device, economic efficiency is improved.

Alternatively, a-phase 4H-SiC (a = 3.0730 Å, b = 10.053 Å,), 6H-SiC (a = 3.0730 Å) with space group C46v-P63mc, hexagonal (wurtzite) crystal structure as follows , b = 10.053 Å), when growing a hexagonal silicon crystal using a SiC substrate, the thermal properties can be significantly improved when forming an electronic device by manufacturing a Si/SiC substrate with a hexagonal silicon crystal grown on the SiC substrate. there is.

Since the hexagonal silicon crystal grown by the present invention is a pure silicon single crystal, it is used in fields related to the silicon industry, such as solar cells, secondary batteries, power semiconductors and optical devices, and monolithic silicon in which optical devices and electronic devices are integrated simultaneously. It can revitalize a new industrial and technological field called photonics OEIC. Among these, in the field of solar cell applications, in the difference between direct and indirect bandgap, which is one of the important characteristics that determines the efficiency of solar cells, the bandgap of hexagonal silicon crystal is compared to the bandgap of existing cubic silicon (~2.5eV). ), it is relatively small at about ~0.7eV, so the range of absorption wavelength of sunlight is widened, so the efficiency of solar cells can be increased by more than 10%, and it can be used as a material for light-emitting devices. In addition, since direct transition light emission is possible, it can be applied as light-emitting devices such as LED and LD and light-receiving devices such as photodiodes.

Moreover, the hexagonal silicon crystal grown according to the present invention has a thermal conductivity that is more than 40% lower than that of a regular cubic silicon crystal, so it is very useful in existing silicon-related industries such as electronic devices and in the microphotonics field. For example, in the case of a SiC substrate on which a hexagonal Si epitaxial layer is grown, the efficiency can be significantly improved at high temperature and high pressure by improving the thermal characteristics of power semiconductors such as Si-based MOSFET/Diode/IGBT, and direct transition light-emitting laser diode-based It is possible to implement a monolithic OEIC for DSP (Digital Signal Processing) and a power device at the same time, and currently, a hybrid OEIC that implements integration by separately making a compound semiconductor-based light emitting device and a silicon-based signal processing IC and a separate module. A system created by combining power semiconductor modules can be implemented very simply and efficiently.

[references]

[19] Yaguang Guo, Qian Wang, Yoshiyuki Kawazoe, and Puru Jena, “A New Silicon Phase with Direct Band Gap and Novel Optoelectronic Properties”, Scientific Reports, 5, 14342 (2015).

[20] Marti Raya-Moreno1, Hugo Aramberri, Juan Antonio, Seijas-Bellido, Xavier Cartoixal, and Riccardo Rurali, “Thermal conductivity of hexagonal Si and hexagonal Si nanowires from first-principles”, Appl. Phys. Lett. 111, 032107 (2017).

1 is a diagram showing a hexagonal silicon crystal growth device according to a first embodiment of the present invention.
Figure 2 is an exploded perspective view of the reaction boat in the embodiment of Figure 1 with the cover removed.
Figure 3 is an exploded perspective view showing another example of a reaction boat.
Figure 4a is another example of a reaction boat in which the raw material loading part and the crystal growth part are joined using graphite screws, and Figure 4b is an example of the raw material loading part and the crystal growth part being joined by fitting.
Figure 5 is a schematic diagram of hexagonal silicon crystal growth according to the present invention.
FIGS. 6A to 6E are photographs and EDS data of the growth starting point of the silicon crystal grown according to the embodiment of FIG. 1.
7A to 7C are optical photographs of hexagonal silicon crystals grown according to an experimental example of the present invention.
Figure 8 is a Raman spectrum result of a hexagonal silicon crystal grown according to an experimental example of the present invention.
Figure 9 is a Raman spectrum result of the upper surface of a hexagonal silicon crystal grown according to an experimental example of the present invention.
Figure 10 is a diagram showing the results of an XRD 2θ/ω scan related to a hexagonal silicon crystal grown according to the present invention.
Figures 11A to 11I are diagrams showing simulation data by changing variables that can be used to determine the size of a hexagonal silicon crystal.
Figure 12 is a diagram showing a hexagonal silicon crystal growth device according to a second embodiment of the present invention.
Figure 13 is an exploded perspective view of the reaction boat in the embodiment of Figure 12 with the cover removed.
14A to 14E are diagrams illustrating semiconductor devices using hexagonal silicon crystals.

Hereinafter, with reference to the attached drawings, the present invention will be described in detail so that those skilled in the art can easily practice it. Elements indicated with the same symbol in the drawings refer to the same element.

1 shows a hexagonal silicon crystal growth device according to a first embodiment of the present invention. The hexagonal silicon crystal growth device according to the present invention is a device for growing hexagonal silicon crystals by the HVPE method. Referring to FIG. 1, the hexagonal silicon crystal growth apparatus largely includes a reaction tube 100, a reaction boat 200 disposed within the reaction tube 100, and a gas supply unit ( 300) and a heating unit 400 that heats the inside of the reaction tube 100.

It is preferable to use a quartz tube as the reaction tube 100, and it is preferable to use a hot wall furnace composed of three general heater furnaces as the heating unit 400, but it is limited to this. It doesn't work.

The reaction boat 200 refers to a module combining the raw material loading unit 210 and the crystal growth unit 220, and the raw material loading unit 210 and the crystal growth unit 220 are arranged vertically. FIG. 2 is an exploded perspective view of the reaction boat 200 of the embodiment of FIG. 1 with the cover 212 removed.

The raw material mounting unit 210 has a cylindrical shape with a substantially square bottom, but is not limited to this and may be formed into a cylindrical or other cylindrical cross-section. One or more through holes 500 are formed in the cylindrical bottom surface 211.

Mixed raw materials 230 are disposed on the bottom surface 211 of the raw material loading unit 210, and at this time, the mixed raw materials 230 are disposed in a state that does not block the through hole 500. The mixed raw material 230 is a mixture of solid silicon (Si), aluminum (Al), and gallium (Ga). Silicon is a raw material for growing hexagonal silicon crystals, and metallurgical grade silicon can be used. Aluminum acts as a catalyst for nucleation necessary to grow hexagonal silicon crystals. In addition, gallium melts silicon, which is a raw material, and promotes the reaction with the halogenation reaction gas described later, prevents oxidation of the raw material and facilitates contact with the halogenation reaction gas, and, like aluminum, promotes nuclear growth on the substrate. It acts as a catalyst for

The mixing ratio of silicon: aluminum: gallium in the mixed raw materials is 1:1~2:1~5, preferably 1:1:2.

It is desirable to cover the upper part of the raw material loading part 210 with a cover 212. It is preferable that the cover 212 be formed with a hole or open on one side so that the supply pipes 321 and 331 can supply gas into the raw material mounting part 210.

The crystal growth unit 220 is disposed at the lower part of the raw material loading unit 210 and has a substantially rectangular shape similar to the shape of the raw material loading unit 210, but is not limited thereto and is formed in the shape of a cylinder or other cross-sectional shape. It can be. In the crystal growth portion 220, a crystal shape frame 240 that can define the shape in which the hexagonal silicon crystal grows is formed concavely. This crystal shape frame 240 may be formed in a cylindrical or square cylinder shape, but is not limited thereto. The diameter L (or the length of one side) or the depth d of the crystal shape frame 240 can be determined according to the desired shape of the silicon crystal. At this time, when the diameter L is large, it is desirable that the depth d is also increased proportionally. For example, if you want to form a silicon crystal in a plate shape, if the diameter L is 2 inches, the depth d can be 500 μm, and if the diameter L is 4 inches, the depth d can be 1 mm or more.

The crystal growth portion 220, especially the crystal shape frame 240, is preferably made of graphite or carbon-coated graphite.

Since the hexagonal silicon crystal growth device according to an embodiment of the present invention does not require a separate growth substrate, hexagonal silicon crystals can be grown directly on the crystal shape frame 240.

Alternatively, a separation substrate (not shown) may be placed on the crystal frame 240. When a hexagonal silicon crystal is grown directly on the crystal shape frame 240, a process to separate the crystal shape frame 240 and the hexagonal silicon crystal is required. However, when a separation substrate is placed on the crystal shape frame 240, the crystal shape is Separation of the frame 240 and the hexagonal silicon crystal becomes easier. The separation substrate preferably has the same shape as the bottom of the crystal frame 240, but does not necessarily have to have the same shape. For example, even if the crystal frame 240 has a square cylinder shape, the separation substrate may have a disk shape. The separation substrate may be selected from the group consisting of graphite, silicon carbide, silicon, sapphire, quartz, ceramic, and various commercial substrates (GaN, GaAs, InP, Ga ₂ O ₃ , etc.). When a hexagonal silicon crystal is grown using a separation substrate, the separation substrate can be removed through a lapping process and a polishing process after the growth of the hexagonal silicon crystal is completed.

As another alternative, a-phase 4H-SiC (a = 3.0730 Å, b = 10.053 Å,), 6H-SiC (a = 3.0730 Å) with space group C46v-P63mc, hexagonal (wurtzite) crystal structure as follows , b = 10.053 Å), a SiC substrate such as this can be placed in the crystal shape frame 240, and a hexagonal silicon crystal can be grown on this SiC substrate. When a Si/SiC substrate with hexagonal silicon crystals grown on a SiC substrate is manufactured and an electronic device is formed as described later, the thermal properties of power semiconductors such as Si-based MOSFET/Diode/IGBT are improved and efficiency is significantly increased at high temperature and high pressure. There are benefits that can be improved.

Although FIG. 2 shows one crystal shape frame 240 being formed in the crystal growth portion 220, a plurality of such crystal shape frames may be formed. In Figure 3, a crystal growth portion 220 in which three crystal shape frames 241, 242, and 243 are formed is shown. The crystal shape frames 241, 242, and 243 may have different diameters and depths, so that a plurality of silicon crystals of a desired shape can be grown in a single growth process. At this time, in order to keep the pressure inside the crystal shape frames 241, 242, and 243 the same, each crystal shape frame 241, 242, and 243 may be connected to each other as shown in FIG. 3, but is not limited to this and can be connected to each other. It can be formed to be separated. Three through holes 500 are formed in the raw material mounting portion 210 in accordance with these three crystal shape frames 241, 242, and 243. Additional through holes 500 may be formed as needed.

Meanwhile, it is preferable that the raw material loading unit 210 and the crystal growth unit 220 are in close contact with each other without a gap, and that an appropriate pressure is maintained within the crystal shape frame 240 of the crystal growth unit 220, as will be described later. In order to bring the raw material mounting unit 210 and the crystal growth unit 220 into close contact, the self-weight of the raw material mounting unit 210 may be used, a separate coupling and holding mechanism, or a fitting coupling may be used. In Figure 4a, an example of a coupling holding mechanism is shown to couple the raw material mounting part 210 and the crystal growth part 220 using a graphite screw, and in Figure 4b, the raw material mounting part 210 is shown without a separate coupling holding mechanism. It is illustrated that it is fitted into the growth portion 220 to ensure close contact. Alternatively, it is also possible to couple the raw material loading portion and the crystal growth portion with a clamp or the like.

The gas supply unit 300 includes an atmospheric gas supply unit 310 that supplies an atmospheric gas such as nitrogen, a nitriding reaction gas supply unit 320 that supplies a nitriding reaction gas such as ammonia (NH ₃ ), and a nitriding reaction gas supply such as hydrogen chloride (HCl). It is provided with a halogenation reaction gas supply unit 330 that supplies a halogenation reaction gas, and each gas supply unit supplies gas to the reaction tube 100 through supply pipes 311, 321, and 331.

The atmospheric gas supply unit 310 supplies atmospheric gas, for example, nitrogen, through the atmospheric gas supply pipe 311, thereby creating a nitrogen atmosphere inside the reaction tube 100 and the reaction boat 200. In Figure 1, the atmospheric gas supply pipe 311 is shown as being outside the reaction boat 200, but if necessary, an opening is formed in the cover 212 to directly supply the atmospheric gas inside the reaction boat 200. . In this case, the silane trichloride and metal chloride gas (AlCl _{n ,} GaCl _n ) generated by the mixed raw material 230 and the halogenated reaction gas are discharged through the through hole ( It is possible to move the gas to the crystal growth unit 220 through 500 and maintain a stable gas flow in the reaction tube 100.

The halogenation reaction gas supply pipe 331 connected to the halogenation reaction gas supply unit 330 directly ejects the halogenation reaction gas to the mixed raw materials mounted on the raw material loading unit 210, producing silane trichloride and metal chloride gas (AlCl _n, GaCl _n ) promotes the production of

The nitriding reaction gas supply pipe 321 connected to the nitriding reaction gas supply unit 320 supplies the nitriding reaction gas to the crystal growth unit 220 through the through hole 500 of the raw material mounting unit 210. Therefore, it is most preferable that the outlet of the nitriding reaction gas supply pipe 321 is disposed near the through hole 500 of the raw material mounting part 210, but it is not limited to this, and any location where the nitriding reaction gas can flow smoothly may be used.

A method of growing a hexagonal silicon crystal using the hexagonal silicon crystal growth apparatus according to the present invention will be described.

First, the mixed raw material 230, which is a mixture of solid silicon, aluminum, and gallium, is evenly disposed on the raw material loading part 210, but does not block the through hole 500. At this time, the mixing ratio of silicon: aluminum: gallium of the mixed raw materials is 1: 1 to 2: 1 to 5, preferably 1: 1: 2.

The crystal growth section 220 is disposed below the raw material loading section. If necessary, a separate coupling holding mechanism can be used.

Next, the heating unit 400 is operated to heat the reaction tube 100 to 1150-1350°C. At this time, before raising the temperature of the reaction boat 200, nitrogen, an atmospheric gas, is flowed, and a certain amount of ammonia, a nitriding reaction gas, is flowed into the reaction boat 200. The nitriding reaction gas supply pipe 321 that supplies the nitriding reaction gas is preferably formed of a quartz pipe.

Next, when the temperature of the reaction tube 100 is stabilized, hydrogen chloride, a halogenation reaction gas, is supplied to the raw material loading unit 210. The supplied hydrogen chloride reacts with the mixed raw materials silicon, aluminum, and gallium, respectively. That is, silicon reacts with hydrogen chloride to generate silane trichloride (Si+3HCl→SiHCl ₃ +H ₂ ), aluminum reacts with hydrogen chloride to generate AlCl, and gallium and hydrogen chloride react to generate GaCl _n (n=1). , 2, 3...) occurs.

At this time, gallium diffuses on the graph surface of aluminum and silicon among the mixed raw materials, removing most of the oxide and nitride films formed on the surfaces of aluminum and silicon. That is, oxidation and nitride occur in silicon and aluminum in a high-temperature atmosphere, but as a small amount of gallium diffuses to their surfaces, the oxide and nitride films are removed and activated during the temperature increase process. Therefore, gallium activates aluminum and promotes the reaction of aluminum with hydrogen chloride to produce AlCl. In addition, gallium is vaporized and flows into the through hole 500 of the raw material mounting part 210 to help generate AlN nanomaterials.

Next, SiHCl ₃ , AlCl and GaCl _n generated by the reaction of mixed raw materials and hydrogen chloride are injected into the through hole 500 of the raw material mounting part 210 and react with ammonia, a nitriding reaction gas, in the crystal growth part 220 to grow crystals. A hexagonal silicon crystal nucleus is formed on the surface of the crystal shape frame 240 of the part 220.

The nucleus for the hexagonal silicon crystal is a nano-shaped AlN nucleus containing Al and N by mixed AlCl, and adsorbed atoms are grown here, allowing SI nuclei in the early stages of growth to coexist. The bond between Al and N is a covalent material with a wurtzite structure or a hexagonal 2H structure, forming a hexagonal structure. Accordingly, these Si nuclei grow rapidly with a purely hexagonal 2H structure. The growth of hexagonal silicon crystals proceeds as the main growth mode due to the high partial pressure of silane trichloride in the concave crystal shape frame 240 of the crystal growth section 220.

Afterwards, if the amount of silicon raw material is sufficient, a certain hexagonal silicon crystal can be formed. At this time, the Si nucleus contained in Al and N, which serve as the nucleus for the hexagonal silicon crystal, can grow rapidly in the longitudinal direction (002) plane, but due to the pressure inside the crystal shape frame 240 of the crystal growth portion 220. By suppressing this, growth on six hexagonal sides can be induced to form a hexagonal silicon crystal. The pressure inside the crystal shape frame 240 of the crystal growth unit 220 can be obtained by arranging and combining the raw material mounting unit 210 and the crystal growth unit 220 vertically.

Figure 5 is a schematic diagram of hexagonal silicon crystal growth according to the present invention. The lower part of Figure 5 is the process of forming the nucleus of AlN, where SiHCl ₃ , AlCl, GaCl _n and ammonia gas react to adsorb gallium, aluminum and carbon to the crystal frame 240, and AlN series (C, A micro cluster of O adsorption is formed. These microgroups have a hexagonal or nearly circular shape formed of a semi-transparent nanomembrane, have no intrinsic crystallinity, and take the form of semi-crystalline microneedles in a structurally very weak shell state. These microneedles develop into a new type of material in a saturated SiCl _n atmosphere in a short period of time and act as absorbers to form Si microneedles. At this time, the Si microneedle has a hexagonal structure of a covalent material with a Wurzeitz structure or a hexagonal 2H structure.

As the reaction continues, parasitic Si microneedles containing Al and N grow explosively, and Si As the concentration increases very sharply, the atoms push out the Al, N, and C atoms, ultimately forming Si microneedles in the form of Si single crystals [21]. In other words, if the concentration of Si increases more rapidly than the concentration of Al, Si atoms outcompete and occupy the positions of Al atoms. At this time, since one direction (002) is suppressed, growth occurs in the side direction of the six sides of the hexagon, and the hexagonal silicon crystal grows in a plate shape.

[references]

[22] D. J. Larkin, P. G. Neudeck, J. A. Powell, and L. G. Matus, Site-competition epitaxy for superior silicon carbide electronics. Appl. Phys. Lett. 65, 1659-1661 (1994).

Afterwards, hexagonal silicon crystals grow into the most stable hexagonal shape along the hexagonal structure of the AlN core. Silicon crystals grow rapidly to form hexagonal silicon crystals in a plate shape with a diameter of tens of μm to several inches and a thickness of several mm. At this time, the substituted Al and N atoms are pushed to the surface by high temperature and are discharged.

FIGS. 6A to 6E are results showing that Si is adsorbed while hexagonal AlN nuclei grow on the crystal shape frame 240 of the crystal growth portion 220. Figure 6a shows a FE-SEM photograph of a nano-type mixture of Al and N and the EDS results of that portion. Figure 6b is an enlarged FE-SEM photo, showing the AlN portion at the root (growth start point: top of the photo) and the Si shape at the hexagonal portion (bottom of the photo), confirming the hexagonal structure. Figures 6c to 6e show the results of sequentially measuring EDS in the area where the nucleus was formed and the hexagonal silicon crystal was grown (shown in the photo), and it can be seen that the ratio of Al and N decreases from the root, while the Si ratio increases.

According to an embodiment of the present invention, the growth conditions and experimental data of hexagonal silicon crystals are shown in Table 1 below.

condition Experiment reaction tube temperature 1150-1350℃ 1200℃ hydrogen chloride 200~1000 sccm 500sccm growth time 1 hour to 5 hours 100 minutes Amount of silicon in mixed raw materials 10~100g 20g Amount of aluminum in mixed raw materials 10~100g or less 20g or less Amount of gallium in mixed raw material 10~100g or less 30g growth rate 0.1~1.0mm/h 0.2mm/h ammonia 1000-5000 sccm 500sccm nitrogen 1000-5000 sccm 5000 sccm Doping material Mg, Te, Ge, B, P, Sb -

The results of growing hexagonal silicon crystals under the experimental conditions in Table 1 are explained as follows. Hydrogen chloride, ammonia, and nitrogen gas were supplied at constant rates of 500 sccm, 500 sccm, and 5000 sccm, respectively. The growth temperature was 1200°C and the growth time was 100 minutes. At this time, the maximum growth rate of the hexagonal silicon crystal was 0.2 mm/h, and hexagonal silicon crystals with a width of 1 to 2 mm and a thickness of 250 to 370 μm or more were grown. The mixed raw materials used were 20 g of Si, 20 g of Al, and 30 g of Ga.

The hexagonal silicon crystals obtained in this way are shown in Table 2 below.

form Hexagonal substrate shape thickness 370 μm diameter 1 mm to 2 mm ingredient top surface 100% hexagonal Si bottom surface Hexagonal Si mixed with AlN

7A to 7C are optical photographs of hexagonal silicon crystals grown according to experimental examples of the present invention. Figure 7a is a hexagonal silicon crystal and has a hexagonal plate shape. Figure 7b shows a hexagonal silicon crystal, in which two hexagonal plate-shaped crystals are connected. Figure 7c is a photograph showing the thickness of the hexagonal silicon crystal substrate of Figure 7a measured with a micrometer, and it can be seen that the thickness is 370 μm.

Figure 8 shows the Raman spectrum results to determine changes in the structural properties of hexagonal silicon crystals grown according to an experimental example of the present invention, measured at room temperature (300 °K) using a 532 nm laser DXR 2 Smart Raman Spectrometer device from Thermo Fisher Scientific. Measured. By measuring the surface of the initial state of the hexagonal silicon crystal, the strongest Raman peak was observed at 518 ㎝ ^-1 , and peaks at 501 ㎝ ^-1 , 587 ㎝ ^-1 , 637 ㎝ ^-1 , and 650 ㎝ ^-1 were also observed. The main Raman peak at 518 cm ^-1 is the peak of the A _1g mode of single crystal hexagonal Si, and the second separated peak at 501 cm ^-1 is the peak of the E _1g mode of hexagonal Si. The 587 cm ^-1 , 637 cm ^-1 , and 650 cm ^-1 peaks are typical Raman peaks of nano AlN and are results that prove the growth mechanism of the hexagonal silicon crystal of the present invention (FIG. 5). For reference, in the case of cubic Si, only a single peak at 521 cm ^-1 appears.

Figure 9 is a Raman spectrum result to determine changes in the structural characteristics of the grown upper surface hexagonal silicon crystal. The strongest Raman peak was observed at 516 ㎝ ^-1 , and peaks at 507 ㎝ ^-1 and 494 ㎝ ^-1 were also observed. As in Figure 8, the peaks at 587 cm ^-1 , 637 cm ^-1 , and 650 cm ^-1 were not measured. The 516 ㎝ ^-1 , 507 ㎝ ^-1 , and 494 ㎝ ^-1 peaks are the peaks of the A _1g , E _1g , and E _2g modes of hexagonal Si, and for the first time, a hexagonal silicon crystal in which three peaks were separated was obtained, and this case is It can be confirmed that the invention is the first. Typical Raman peaks of nano AlN, such as 587 cm ^-1 , 637 cm ^-1 , and 650 cm ^-1 peaks, were not measured, showing that the AlN component disappears as it grows upward and a pure hexagonal silicon crystal can be obtained. Therefore, it is confirmed that the hexagonal silicon crystal grown according to the present invention has a different crystal structure from cubic Si and is pure Si without any other substances mixed in.

For reference, the references for Raman peaks are as follows [22]-[25].

[22] S. Piscanec, M. Cantoro, A. C. Ferrari, J. A. Zapien, Y. Lifshitz, S. T. Lee, S. Hofmann and J. Robertson, Phys. Rev. B 68, 241312R (2003).

[23] M. Khorasaninejad, J. Walia and S. S. Saini, Nanotechnology, 23, 275706 (2012).

[24] M. Luyao, L. Sudarat, D. Joshua and M. Stephen, RSC Adv. 6, 78818 (2016).

[25] Bennett E. Smith, Xuezhe Zhou, Paden B. Roder, Evan H. Abramson, and Peter J. Pauzauskie, "Recovery of hexagonal Si-IV nanowires from extreme GPa pressure" JOURNAL OF APPLIED PHYSICS 119, 185902 (2016) .

Figure 10 is a diagram showing the results of an XRD 2θ/ω scan related to a hexagonal silicon crystal grown according to the present invention. Hexagonal silicon crystals were crushed as shown in the photo at the top left, randomly extracted, and 2θ values were measured in the range of 20° to 120°. The XRD 2θ/ω results were obtained using Rigaku's Smartlab high-resolution , HR-XRD) was used to analyze it.

As can be seen in Figure 10, 2θ=28.28°, 47.32°, 83.56°, 94.98° and 106.76° were observed. According to ICSD ID 30396 (Physical Review, series 3. B-condensed Matter (18,1978-)(1992).46, 10086-10097), 2θ=28.28° is (002), 2θ=47.32° is (110), 2θ=83.56° is (212), 2θ=94.98° is (006), and 2θ=106.76° is the (220) plane, cubic silicon F-43m space group (lattice constant a=5.39Å, c=5.39). A peak at 2θ = 83.56°, which does not appear in Å), was measured. This is a result that clearly confirms that the hexagonal silicon crystal grown by the present invention is a P63mc space group (lattice constant a = 3.8 Å, c = 6.26 Å).

As a result of analyzing the measurement results using the This result clearly shows that the hexagonal silicon crystal of the present invention is a D46h space group with a stacking array of ABABABAB at a direct band gap gap value (1.69 eV at the Γ-point). do.

11A to 11I are graphs showing the relationship between several variables to determine the size of a hexagonal silicon crystal. In order to change the internal pressure of the crystal shape frame 40 during the growth of the hexagonal silicon crystal, the growth temperature of the hexagonal silicon crystal, the weight and volume of the raw material mounting part 210, and the diameter (area) of the crystal shape frame 240. This is a graph based on simulation results that change depth, volume, etc.

At this time, assuming that the raw material mounting unit 210 has an approximately rectangular shape (150 mm x 60 mm x 10 mm) and weighs 1 kg, the crystal shape frame according to the diameter L, depth d, and temperature of the crystal shape frame 240 (240) Internal pressure changes can be predicted. The pressure inside the crystal frame 240 is the sum of the pressure formed by the weight of the raw material mounting part 210 and the pressure formed by the temperature.

When the diameter L of the crystal shape frame 240 is changed from 0.005 m to 0.1524 m (6 inches), the depth d is changed from 100 μm to 1000 μm, and the growth temperature is changed from 1150°C to 1350°C, the crystal shape frame (240) The internal pressure was predicted to be in the range of 0.1–0.16 GPa.

Looking at this in detail, the graph in FIG. 11a is a graph showing the relationship between the depth d and pressure of the crystal shape frame 240 at a temperature of 1150°C. The depth d is changed from 100 μm to 1000 μm, and the diameter L (indicated as Φ in the drawing) It shows the range of pressure when changed from 0.005 m to 0.1524 m. In other words, it can be seen that as the volume of the crystal frame 240 increases, the internal pressure decreases.

Likewise, the graph in Figure 11b shows the range of internal pressure when changing the temperature to 1200°C, the graph in Figure 11c shows the range of internal pressure when changing to 1250°C, the graph in Figure 11d shows 1300°C, and the graph in Figure 11e shows the range of internal pressure when changing to 1350°C. It can be seen that the maximum is about 0.155 GPa. Referring to FIGS. 11A to 11E, it can be seen that as the depth increases, the internal pressure decreases, and as the temperature increases, the internal pressure increases. Therefore, it is possible to form high-quality, large-area hexagonal silicon crystals by appropriately selecting the depth d and diameter L of the crystal shape frame, which determine the size of the hexagonal silicon crystal.

Considering that the internal pressure range of the crystal shape frame 240 is 0.1-0.16 GPa, which was several tens of GPa when growing a conventional hexagonal silicon crystal, according to the present invention, hexagonal silicon crystals can be formed at extremely low pressure (1 GPa or less). It has the effect of growing silicon crystals.

11F to 11I are graphs showing the relationship between growth temperature and internal pressure when the depth d of the crystal shape frame 240 is set to 100 μm, 300 μm, 500 μm, and 1000 μm, respectively.

Looking at these simulation results, it is possible to form a hexagonal silicon crystal of a desired size by adjusting the growth temperature, the depth and diameter of the crystal shape frame 240, and the weight and volume of the raw material mounting part 210.

In addition, in the simulations of FIGS. 11A to 11I, only the pressure due to the weight and volume of the raw material mounting part 210 was considered, but when a separate coupling holding mechanism (for example, a screw in FIG. 4A or a clamp not shown) is used, , the pressure caused by this connection holding mechanism may also be considered. Alternatively, a separate pressure control device may be used to control the pressure inside the crystal frame 240.

Next, with reference to FIG. 12, a hexagonal silicon crystal growth device according to a second embodiment of the present invention will be described.

The hexagonal silicon crystal growth device according to the second embodiment of the present invention is a device that simultaneously grows bulk-type hexagonal silicon crystals and needle-type hexagonal silicon crystals by the HVPE method. The hexagonal silicon crystal growth apparatus according to this second embodiment includes a reaction tube 100, a reaction boat 200 disposed within the reaction tube 100, and a gas supply unit ( It is similar to the device of the first embodiment in that it is provided with a heating unit 400 that heats the inside of the reaction tube 100, and the structure of the reaction boat 200 is different from the first embodiment.

In the reaction boat 200 in the second embodiment, the raw material loading portion 210 and the crystal growth portion 220 are arranged vertically, and a needle-shaped crystal growth portion 260 is further formed by being connected to the raw material loading portion 210. there is. FIG. 13 is an exploded perspective view of the reaction boat 200 of the embodiment of FIG. 12 with the cover 212 removed.

The raw material loading unit 210 and the needle-shaped crystal growth unit 260 have an integrated cylindrical shape, but are not limited thereto. The needle-shaped crystal growth portion 260 is preferably formed at a lower position on the bottom compared to the raw material mounting portion 210. In the needle-shaped crystal growth portion 260, a growth substrate 280 on which needle-shaped hexagonal silicon crystals are grown, and a collection substrate 270 disposed below the growth substrate 280 are disposed. The growth substrate 280 is placed with the crystal growth surface facing downward, and it is preferable to use a silicon substrate. For example, a Si (111) substrate or a Si (100) substrate can be used, and the surface direction It can be used regardless.

The collection substrate 270 is a substrate for collecting hexagonal silicon crystals grown on the growth substrate 280 when they fall down due to their own weight. Accordingly, the collection substrate 270 is spaced apart from the growth substrate 280 in the vertical direction and is disposed below the growth substrate 280 . Additionally, the collection substrate 270 may be in the form of a flat plate, or alternatively, may be in the shape of a tray with a guide installed on the side.

The through hole 500 of the raw material mounting unit 210 is not limited to this, and may be formed in a cylindrical or other cylindrical cross-section shape. One or more through holes 500 are formed in the cylindrical bottom surface 211.

The mixed raw material 230 is disposed on the bottom surface 211 of the raw material loading unit 210, and in this case, the mixed raw material 230 is disposed in a state that does not block the through hole 500, which is the same as the first embodiment. The mixed raw material 230 is a mixture of solid silicon (Si), aluminum (Al), and gallium (Ga).

The crystal growth portion 220 is disposed below the raw material mounting portion 210, and the crystal shape frame 240 is disposed centered on the through hole 500 of the raw material mounting portion 210.

A hexagonal silicon crystal growth method using the hexagonal silicon crystal growth apparatus according to the second embodiment will be described as follows.

As in the first embodiment, a mixed raw material of solid silicon, aluminum, and gallium is placed in the raw material loading section 210, and a growth substrate 280 and a collection substrate are placed in the needle-shaped crystal growth section 260. Install (270).

Next, the heating unit 400 is operated to heat the reaction tube 100 to 1150-1350°C. At this time, before raising the temperature of the reaction boat 200, nitrogen, which is an atmospheric gas, is flowed, and a certain amount of ammonia, which is a nitriding reaction gas, is flowed into the crystal growth part 220.

Next, when the temperature of the reaction tube 100 is stabilized, hydrogen chloride, a halogenation reaction gas, is supplied to the raw material loading unit 210. The supplied hydrogen chloride reacts with the mixed raw materials silicon, aluminum, and gallium, respectively, to generate silane trichloride, AlCl, and GaCl _n . These silane trichlorides, AlCl and GaCl _n flow to the lower crystal growth portion 220 through the through hole 500, while also flowing toward the lateral needle-like crystal growth portion 260.

In the crystal growth section 220, bulk hexagonal silicon crystals grow by the mechanism described in the first embodiment.

The needle-shaped crystal growth portion 260 reacts with ammonia, a nitriding reaction gas, in the growth substrate 280 to form nuclei for hexagonal silicon crystals on the surface of the growth substrate 280, and then the hexagonal silicon crystals grow. . The growth mechanism of these needle-like hexagonal silicon crystals is incorporated herein by reference in the applicant's Patent No. 10-2149338, which is incorporated herein by reference.

According to the second embodiment of the present invention, bulk hexagonal silicon crystals and needle-shaped hexagonal silicon crystals can be grown simultaneously through one growth process. That is, the bulk hexagonal silicon crystal grown in the crystal shape frame 240 suppresses growth in the (002) direction to maximize growth in the six-sided direction of the hexagon, and the growth substrate 280 of the needle-shaped crystal growth portion 260 The hexagonal silicon crystal grown in maximizes growth in the (002) direction and becomes a needle-shaped hexagonal silicon crystal.

According to this second embodiment, it is useful because it is possible to grow two types of crystals: bulk type and needle type.

As discussed above, according to the present invention, hexagonal silicon crystals can be grown by the HVPE method using mixed raw materials consisting of silicon, aluminum, and gallium. These hexagonal silicon crystals are large (mm to inch) and have a stable hexagonal structure at room temperature and pressure.

In addition, the present invention can control the silicon crystal growth rate by adjusting the mixing ratio of silicon, aluminum, and gallium in the mixed raw materials, and the diameter, thickness, and doping of the substrate can be adjusted according to the crystal growth rate. Additionally, according to the present invention, hexagonal silicon crystals can be grown without a base substrate.

Moreover, the present invention can grow bulk hexagonal silicon crystals and simultaneously grow needle-like hexagonal silicon crystals.

Since the hexagonal silicon crystal grown by the present invention is a hexagon of pure Si single crystal, it is useful in fields related to the silicon industry, such as solar cells and medical fields, and because the difference between the direct bandgap and indirect bandgap is relatively small, it is useful in microphotonics. It has great utility in this field.

14A to 14E are examples of semiconductor devices using hexagonal silicon crystals grown according to an embodiment of the present invention.

A semiconductor device can be manufactured by cutting a hexagonal silicon crystal grown according to an embodiment of the present invention into a desired shape and then depositing a metal layer or an oxide layer. At this time, the cutting process may use a known cleaving device.

14A to 14E illustrate that the semiconductor device according to the present invention is a surface-mounted semiconductor device, but is not limited thereto. That is, a semiconductor device may be formed by forming a metal layer or an oxide layer on different surfaces, or by contacting an external electrode (not shown) rather than forming an electrode directly on a hexagonal silicon crystal.

Figure 14a is an example of forming a metal-semiconductor (MS) diode device using a hexagonal silicon crystal. The device of FIG. 14A has first and second electrodes 21 and 22 formed on one side of a hexagonal silicon crystal 10, respectively. These electrodes can be formed using a lithography process, a shadow mask, or a dedicated jig.

To make the device of FIG. 14A into an MS diode, the first electrode 21 forms an ohmic contact and the second electrode 22 forms a Schottky contact, or the first electrode 21 forms a Schottky contact. The second electrode 22 forms an ohmic contact, or forms an electrode such that both the first electrode 21 and the second electrode form a Schottky contact.

At this time, the metal material that can form ohmic contact with the hexagonal silicon crystal is a metal silicon compound (Silicides) such as Al, PtSi, and TiSi ₂ , and the thickness of the metal layer is preferably 100 Å to 2000 Å.

In addition, metal materials capable of forming Schottky contact with hexagonal silicon crystals include Pt, Ag, Al, Au, Cr, Cu, Hf, In, Mg, Mo, Ni, Pg, Pd, Ta, Ti, and W. It can be selected from the group, and the thickness of the metal layer is preferably 100 Å to 1000 Å.

When the first electrode 21 of the MS diode in FIG. 14A is formed with an ohmic contact and the second electrode 22 is formed with a Schottky contact and power is applied, it becomes a light emitting diode device with a central wavelength of 740 nm.

Referring to FIG. 14b, in the MOS diode device according to the present invention, one of the first electrode 21 and the second electrode 22 is formed on an oxide film. For convenience of explanation, the first electrode 21 is formed on the oxide film 31. It is assumed to be formed above.

In the electrode formation process of the device of FIG. 14B, metal is first deposited on one side of the hexagonal silicon crystal 10 and then heat treated to form the second electrode 22 as an ohmic contact electrode. Thereafter, before forming the first electrode, an oxide film 31 is deposited on the first electrode formation position of the hexagonal silicon crystal. The material of this oxide film 31 is SiO ₂ or the like, and may be replaced with a nitride film containing Si ₃ N ₄ . In this specification, the term oxide film is used to refer to both an oxide film and a nitride film. Next, metal is deposited on the oxide film 31 to form the first electrode 21. These first and second electrodes and oxide films can be formed using a lithography process, a shadow mask, or a dedicated jig.

Figure 14c is a diagram showing a MESFET device or a dual MS Schottky diode device. The device of FIG. 14C forms a first electrode 21 and a second electrode 22 on one side of the hexagonal silicon crystal 10, respectively, and forms a first electrode 21 and a second electrode 22 on the side between the first electrode 21 and the second electrode 22. The third electrode 23 is formed.

In order to make the device of Figure 14c into a MESFET device, the first electrode 21 and the second electrode 22 are to form an ohmic contact, and the third electrode 23 is to form a Schottky contact, so that the first electrode ( 21), the second electrode 22, and the third electrode 23 operate as a source, drain, and gate, respectively.

In order to make the device of Figure 14c into a dual Schottky diode device, the first electrode 21 and the second electrode 22 are to form a Schottky contact, and the third electrode 23 is to form an ohmic contact to form a dual Schottky diode device. It operates as a key diode device.

Figure 14d is a diagram showing a MOSFET device using a hexagonal silicon crystal. The device shown in FIG. 14D is a device in which the third electrode 23 is formed on the oxide film 31 in the device shown in FIG. 14C. That is, the first electrode 21 and the second electrode 22 are in ohmic contact with the hexagonal silicon crystal 10, and the third electrode 23 is formed on the oxide film 31 to form the first electrode 21 to the second electrode 22. The three electrodes 23 operate as source, drain and gate, respectively.

Figure 14e is a diagram showing a dual MOS diode device using a hexagonal silicon crystal. The device shown in FIG. 14E is a device in which the first electrode 21 and the second electrode 22 are formed on an oxide film from the device shown in FIG. 14C, respectively. That is, the first oxide film 31 is formed at the formation position of the first electrode 21 before the formation of the first electrode 21, and the first oxide film 31 is formed at the formation position of the second electrode 22 before the formation of the second electrode 22. A second oxide film 32 is formed. At this time, the third electrode 23 forms ohmic contact.

All of these devices in FIGS. 14A to 14E can operate as light-emitting devices or electronic devices.

In particular, a-phase 4H-SiC (a = 3.0730 Å, b = 10.053 Å,), 6H-SiC (a = 3.0730 Å, b) with the following space group C46v-P63mc, hexagonal (wurtzite) crystal structure = 10.053 Å), when forming a semiconductor device using a hexagonal silicon crystal grown on a SiC substrate, thermal properties can be significantly improved.

Although the technical features of the present invention have been described above with a focus on specific embodiments, a person skilled in the art may make various changes and modifications within the scope of the technical idea of the present invention. It's obvious.

100: reaction tube
200: Reaction Boat
210, 210': raw material mounting part 212: cover
230: Mixed raw materials
220: Crystal growth section
240, 241, 242, 243: Crystal shape frame
260: Needle-shaped crystal growth portion
270: Substrate for collection 280: Substrate for growth
300: reaction gas supply unit
310: Atmospheric gas supply unit 311: Atmospheric gas supply pipe
320: Nitriding reaction gas supply unit 321: Nitriding reaction gas supply pipe
330: Halogenation reaction gas supply unit 331: Halogenation gas supply pipe
400: heating unit
500: Through hole

Claims (23)

A hexagonal silicon crystal growth device, comprising:
reaction tube;
a reaction boat disposed on one side of the reaction tube;
a halogenation reaction gas supply pipe supplying a halogenation reaction gas to the reaction boat;
a nitriding reaction gas supply pipe supplying nitriding reaction gas to the reaction boat; and
Heating unit that heats the reaction tube
Including,
The reaction boat is
A raw material loading portion in which at least one through hole is formed in the bottom of the barrel and in which a mixed raw material of solid silicon, aluminum, and gallium is mounted; and
A crystal growth portion disposed below the raw material loading portion and having a concave crystal shape frame of a predetermined shape.
Including,
A hexagonal silicon crystal growth device wherein the internal pressure of the crystal growth unit is obtained by arranging the raw material loading unit and the crystal growth unit vertically. According to paragraph 1,
A hexagonal silicon crystal growth device in which the heating unit heats the reaction tube to a temperature range of 1150-1350°C. According to paragraph 1,
A hexagonal silicon crystal growth device in which the mixing ratio of silicon: aluminum: gallium of the mixed raw materials is 1:1 to 2:1 to 5. According to paragraph 1,
A hexagonal silicon crystal growth device in which the raw material loading unit and the crystal growth unit are coupled by a bonding and holding mechanism or are in close contact with the raw material loading unit's own weight. According to paragraph 1,
A hexagonal silicon crystal growth device wherein the pressure P inside the crystal frame is 0 < P ≤ 1GPa. According to paragraph 1,
A hexagonal silicon crystal growth device in which a separation substrate is disposed on the crystal shape frame of the crystal growth portion. According to paragraph 1,
A SiC substrate is placed on the crystal shape frame of the crystal growth portion,
The SiC substrate has the following space group C46v-P63mc, a-phase 4H-SiC (a = 3.0730 Å, b = 10.053 Å,), 6H-SiC (a = 3.0730 Å) with a hexagonal (wurtzite) crystal structure. , b = 10.053 Å) selected hexagonal silicon crystal growth device. According to paragraph 1,
A hexagonal silicon crystal growth device in which a plurality of crystal shape frames are formed in the crystal growth part, and the shapes or sizes of the plurality of crystal shape frames are the same or different. According to paragraph 1,
The reaction boat is
a second crystal growth portion laterally connected to the raw material loading portion;
It further includes,
A hexagonal silicon crystal growth device including a growth substrate disposed in the second crystal growth portion with the crystal growth surface facing downward. A hexagonal silicon crystal growth method comprising:
Placing a raw material loading unit equipped with a mixed raw material of solid silicon, aluminum, and gallium inside the reaction tube;
Placing a crystal growth portion in which a crystal shape frame is formed at a lower portion of the raw material mounting portion;
Heating the reaction tube to a temperature in the range of 1150-1350°C;
supplying a halogenation reaction gas and a nitridation reaction gas to the mixed raw materials;
reacting the mixed raw materials with the halogenation reaction gas to produce trichlorosilane gas and metal chloride gas;
flowing the generated silane trichloride gas, metal chloride gas, and nitriding reaction gas into the crystal growth unit disposed below the raw material loading unit;
reacting the silane trichloride gas, metal chloride gas, and nitriding reaction gas to generate nuclei in the crystal frame; and
Growing a hexagonal silicon crystal around the generated nucleus;
Including,
A hexagonal silicon crystal growth method, wherein the internal pressure of the crystal growth unit is obtained by arranging the raw material loading unit and the crystal growth unit vertically. According to clause 10,
The step of growing the hexagonal silicon crystal is
A step of replacing Si atoms with trichlorosilane gas centered on the generated nucleus;
Growing a hexagonal silicon crystal by the substituted Si atoms;
A hexagonal silicon crystal growth method comprising. According to clause 10,
The hexagonal silicon crystal growth method wherein the generated silane trichloride gas, metal chloride gas, and nitriding reaction gas flow into the crystal growth section through at least one through hole formed on the bottom surface of the raw material loading section. According to clause 10,
In the step of arranging the crystal growth portion,
A hexagonal silicon crystal growth method in which a separation substrate is placed on the crystal shape frame of the crystal growth portion. According to clause 10,
In the step of arranging the crystal growth portion,
Placing a SiC substrate on the crystal shape frame of the crystal growth portion,
The SiC substrate has the following space group C46v-P63mc, a-phase 4H-SiC (a = 3.0730 Å, b = 10.053 Å,), 6H-SiC (a = 3.0730 Å, b = 10.053 Å) selected hexagonal silicon crystal growth method. According to clause 10,
A substrate placement step of placing a growth substrate on a side of the raw material mounting unit so that the crystal growth surface faces downward;
A hexagonal silicon crystal growth method further comprising: According to clause 15,
flowing the generated silane trichloride gas, metal chloride gas, and nitriding reaction gas toward a growth substrate on a side of the raw material mounting unit;
reacting the silane trichloride gas, metal chloride gas, and nitriding reaction gas to generate nuclei in the growth substrate; and
Growing a hexagonal silicon crystal on the growth substrate centered on the generated nucleus;
A hexagonal silicon crystal growth method comprising. According to clause 10,
A method for growing hexagonal silicon crystals in which the mixing ratio of silicon: aluminum: gallium of the mixed raw materials is 1: 1 to 2: 1 to 5. According to clause 10,
A hexagonal silicon crystal growth method for controlling the growth rate of the hexagonal silicon crystal by pressure inside the crystal shape frame. A hexagonal silicon crystal formed by the method according to any one of claims 10 to 18. A first electrode formed on or connected to one side of a hexagonal silicon crystal formed by the method according to any one of claims 10 to 18; and
A second electrode is spaced apart from the first electrode and formed on the other side of the hexagonal silicon crystal or connected to the other side.
Including,
A hexagonal silicon semiconductor device wherein the one side and the other side are the same side or different sides. According to clause 20,
A third electrode formed between the first electrode and the second electrode
A hexagonal silicon semiconductor device further comprising: According to clause 20,
An oxide film formed between the first or second electrode and the hexagonal silicon crystal.
A hexagonal silicon semiconductor device further comprising: According to clause 22,
An oxide film formed between the first electrode, second electrode, or third electrode and the hexagonal silicon crystal.
A hexagonal silicon semiconductor device further comprising:

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