Systems and methods for processing crystals of metal compounds - Patents.com

Abstract

The present disclosure provides a system and method for forming a block crystal of a metal compound. In some embodiments, a method for forming a block crystal of a metal compound may include: (a) introducing a source metal into a smelting furnace; (b) forming a full or partial vacuum in the smelting furnace and increasing the temperature of the smelting furnace above the melting point of the source metal to form a liquid stream of the source metal; (c) decomposing the liquid stream to generate particles of the source metal; (d) ionizing the particles in an ionization chamber to form ionized particles, the ionization chamber having a temperature above the decomposition temperature of the metal compound; and (e) introducing the ionized particles into a growth chamber comprising a reactive gas that is reactive with the ionized particles, thereby forming a block crystal of the metal compound.

Description

[Background technology]

[0001] (cross reference) This application claims the benefit of U.S. Provisional Application No. 63 / 223,731, filed July 20, 2021, which application is incorporated by reference herein in its entirety.

[0002] (background) Gallium nitride (GaN) is a high-intensity luminescent material that is resistant to high temperatures, high pressures, and radiation. It is also non-toxic and free of contaminants. Due to its wide band gap, GaN-based semiconductor materials have the highest photoelectric conversion efficiency among photovoltaic materials. High-purity GaN is also an important raw material for manufacturing high-performance semiconductor devices and substrates. Compared to silicon carbide and alumina, GaN has better lattice matching and material consistency.

[0003] Generally, GaN crystals are formed using gas-phase or liquid-phase methods. The precursor materials used in these methods are gallium intermediate or gallium compound materials, and when the gallium intermediate or gallium compound materials are produced, many toxic solutions and solvents are used, resulting in a final GaN single crystal block containing many impurities and parasitic reaction products. At the same time, these commonly used methods have lower efficiency (i.e., lower epitaxial growth rates (100-300 micrometers / hour for hydride vapor phase epitaxy (HPVE), 10-80 micrometers / hour for ammonothermal, 20 micrometers / hour for high pressure solution growth (HPSG), and 50 micrometers / hour for sodium flux)). Summary of the Invention [Means for solving the problem]

[0004] (summary) The present disclosure provides systems and methods for processing gallium nitride (GaN) crystals and other metal compound crystals without the use of solvents and catalysts by using physical methods to convert solid metals into ultrafine particles, nucleate such particles, and crystallize them into crystals. Because no toxic solutions or solvents are used, the resulting crystals have fewer impurities and parasitic reaction products.

[0005] An aspect of the disclosure provides a method for forming block crystals of a metal compound, the method including: (a) introducing a source metal into a smelting furnace; (b) forming a full or partial vacuum in the smelting furnace and increasing the temperature of the smelting furnace above the melting point of the source metal to form a liquid stream of the source metal; (c) decomposing the liquid stream to generate particles of the source metal; (d) ionizing the particles in an ionization chamber to form ionized particles, the temperature of the ionization chamber being above the decomposition temperature of the metal compound; and (e) introducing the ionized particles into a growth chamber comprising a reactive gas that is reactive with the ionized particles, thereby forming block crystals of the metal compound.

[0006] In some embodiments, (c) comprises one or more of (1) applying a high pressure gas to the liquid flow, (2) applying ultrasound to the liquid flow, or (3) mechanically vibrating the liquid flow. In some embodiments, (c) comprises (1) applying a high pressure gas to the liquid flow and (2) applying ultrasound to the liquid flow. In some embodiments, (c) comprises (1) applying a high pressure gas to the liquid flow and (2) mechanically vibrating the liquid flow. In some embodiments, (c) comprises (1) applying a high pressure gas to the liquid flow, (2) applying ultrasound to the liquid flow, and (3) mechanically vibrating the liquid flow. In some embodiments, (d) comprises introducing a flow of another inert gas into the ionization chamber, thereby preventing (1) agglomeration of the ionized particles and (2) adhesion of the ionized particles to the ionization chamber. In some embodiments, (b) includes introducing another inert gas into the smelting furnace following the formation of a full or partial vacuum in the furnace. In some embodiments, each of the high pressure gas, the inert gas, and the another inert gas is independently helium, nitrogen, or argon. In some embodiments, (c) is followed by removing a subset of particles larger than a threshold size before reaching the ionization chamber. In some embodiments, the subset of particles is reused. In some embodiments, (c) includes atomizing and vaporizing the liquid stream. In some embodiments, (c) is performed without a solvent.

[0007] In some embodiments, the ionized particles diffuse from the ionization chamber to the growth chamber along a concentration gradient or a temperature gradient. In some embodiments, block crystals of the metal compound are formed in a deposition groove at the bottom of the growth chamber. In some embodiments, the temperature of the growth chamber promotes the growth of the block crystals of the metal compound. In some embodiments, the reactive gas is non-catalytic. In some embodiments, the source metal is a pure metal. In some embodiments, the source metal is a combination of metals. In some embodiments, (b) comprises increasing the temperature of the smelter above the melting point of the metal with the highest melting point in the combination of metals. In some embodiments, the source metal is gallium, aluminum, indium, silicon, or a combination thereof. In some embodiments, the source metal is gallium, the reactive gas is nitrogen or ammonia, and the metal compound is gallium nitride. In some embodiments, the source metal is aluminum, the reactive gas is nitrogen or ammonia, and the metal compound is aluminum nitride. In some embodiments, the source metal is silicon, the reactive gas is methane, and the metal compound is silicon carbide. In some embodiments, the source metal is indium, the reactive gas is nitrogen or ammonia, and the metal compound is indium nitride.

[0008] Another aspect of the disclosure provides an apparatus for forming block crystals of a metal compound, the apparatus comprising: a smelting furnace configured to heat a source metal and form a liquid stream of the source metal; a fragmentation device coupled to the smelting furnace, the fragmentation device configured to generate particles of the source metal from the liquid stream; an ionization chamber coupled to the fragmentation device, the ionization chamber configured to ionize the particles and form ionized particles; and a growth chamber coupled to the ionization chamber, the growth chamber configured to promote growth of the block crystals of the metal compound through reaction between the ionized particles and a reactive gas in the growth chamber.

[0009] In some embodiments, the fragmentation device comprises one or more atomization devices and a water vaporization device. In some embodiments, the one or more atomization devices comprise a gas atomizer, a mechanical vibrator, or an ultrasonic atomizer. In some embodiments, the apparatus further comprises a particle selector disposed between the one or more atomization devices and the water vaporization device. In some embodiments, the particle selector comprises a first plurality of tilted gas holes. In some embodiments, the fragmentation device comprises one or more atomization devices and a water vaporization device, and the apparatus further comprises a particle selector disposed between the one or more atomization devices and the water vaporization device. In some embodiments, the one or more atomization devices comprise a gas atomizer, a mechanical vibrator, or an ultrasonic atomizer. In some embodiments, the apparatus comprises an ion selector disposed between the ionization chamber and the growth chamber. In some embodiments, the particle selector comprises a second plurality of tilted gas holes. In some embodiments, the ionization chamber comprises a particle rotation-suspension setup disposed on a bottom portion of the ionization chamber, the particle rotation-suspension setup configured to generate a plurality of upward inert gas flows introduced by a plurality of straight holes and a plurality of inclined inert gas flows introduced by a third plurality of inclined holes. In some embodiments, the plurality of straight holes and the third plurality of inclined holes (1) are distributed in a substantially circular or irregular shape, (2) intersect with each other or in a substantially alternating pattern, or (3) are distributed substantially uniformly in the bottom portion of the ionization chamber. In some embodiments, the smelting furnace comprises a crucible configured to hold the source metal. In some embodiments, the crucible is sealed. In some embodiments, the crucible is open to the smelting furnace. In some embodiments, the smelting furnace comprises a vacuum exhaust channel configured to remove air from the crucible or the smelting furnace or both and form a full or partial vacuum in the crucible or the smelting furnace. In some embodiments, the furnace comprises a gas channel configured to supply an inert gas to the crucible or the furnace or both.In some embodiments, the vacuum exhaust channel or gas channel is disposed within the upper portion of the crucible or the upper portion of the furnace. In some embodiments, the apparatus further comprises a redirecting channel coupling the furnace to the fragmentation device. In some embodiments, the one or more atomizing devices and the water vaporization device are connected in series or integrated together. In some embodiments, the one or more atomizing devices are multiple atomizing devices, and the multiple atomizing devices are connected in series or integrated together. In some embodiments, the one or more atomizing devices comprise a gas atomizer, a mechanical vibrator, or an ultrasonic atomizer. In some embodiments, the water vaporization device comprises an induction heater, a direct current arc, a plasma source, a microwave source, or a laser. In some embodiments, the growth chamber comprises a deposition-growth chamber. In some embodiments, the deposition-growth chamber comprises a top ion diffusion zone, a bottom growth zone, and an isolation grid disposed between the ion diffusion zone and the growth zone. In some embodiments, the isolation grid comprises a plurality of holes that allow diffusion of ionized particles. In some embodiments, the bottom growth zone comprises a circular deposition groove for growing block crystals of the metal compound. In some embodiments, the fragmentation device is coupled to a bottom portion of the blast furnace, the ionization chamber is coupled to a side of the fragmentation device, and the growth chamber is coupled to an upper portion of the ionization chamber. In some embodiments, the ionization chamber comprises an outlet port for the coarse particles, the outlet port being disposed in the bottom portion of the ionization chamber. In some embodiments, the growth chamber comprises a deposition-growth chamber, the deposition-growth chamber comprising an upper gas accumulation zone, a central ion diffusion zone, a bottom growth zone, a first isolation grid disposed between the central ion diffusion zone and the bottom growth zone, and a second isolation grid disposed between the upper gas accumulation zone and the central ion diffusion zone. In some embodiments, the entrance to the deposition-growth chamber is in the central ion diffusion zone. In some embodiments, the upper gas accumulation zone comprises an excess gas outlet port.

[0010] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in the art from the following detailed description, in which only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modification in various obvious respects, all without departing from the present disclosure. Thus, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

[0011] (Incorporated by reference) All publications, patents, and patent applications mentioned herein are incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent that the publications and patents or patent applications incorporated by reference conflict with the disclosure contained herein, the present specification is intended to supersede and / or take precedence over any such conflicting material. [Brief description of the drawings]

[0012] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also referred to herein as "Figure" and "FIG.").

[0013] [Figure 1] FIG. 1 is a flow chart of a process for producing block crystals of metal compounds according to some embodiments of the present disclosure.

[0014] [Diagram 2] FIG. 2 diagrammatically illustrates a smelting furnace according to some embodiments of the present disclosure.

[0015] [Diagram 3] FIG. 3 illustrates diagrammatically an alternative embodiment of a smelting furnace.

[0016] [Figure 4] FIG. 4 diagrammatically illustrates a first fragmentation device according to some embodiments of the present disclosure.

[0017] [Diagram 5] FIG. 5 illustrates diagrammatically a second embodiment of a fragmentation device.

[0018] [Figure 6] FIG. 6 illustrates diagrammatically a third embodiment of a fragmentation device.

[0019] [Figure 7] FIG. 7 diagrammatically illustrates an ionization chamber for generating ionized particles according to some embodiments of the present disclosure.

[0020] [Figure 8] FIG. 8 illustrates diagrammatically a second embodiment of an ionization chamber for generating ionized particles.

[0021] [Figure 9] FIG. 9 illustrates diagrammatically a third embodiment of an ionization chamber for generating ionized particles.

[0022] [Figure 10] FIG. 10 illustrates diagrammatically a fourth embodiment of an ionization chamber for generating ionized particles.

[0023] [Figure 11] FIG. 11 illustrates diagrammatically a fifth embodiment of an ionization chamber for generating ionized particles.

[0024] [Figure 12] FIG. 12 illustrates diagrammatically a sixth embodiment of an ionization chamber for generating ionized particles.

[0025] [Figure 13] FIG. 13 illustrates diagrammatically a seventh embodiment of an ionization chamber for generating ionized particles.

[0026] [Figure 14] FIG. 14 diagrammatically illustrates a growth chamber for producing block crystals of metal compounds according to some embodiments of the present disclosure.

[0027] [Figure 15] FIG. 15 illustrates diagrammatically a second embodiment of a growth chamber for producing block crystals of a metal compound.

[0028] [Figure 16] FIG. 16 diagrammatically illustrates a vertical apparatus for producing block crystals of a compound, according to some embodiments of the present disclosure.

[0029] [Figure 17] FIG. 17 diagrammatically illustrates a smelting furnace of the apparatus of FIG. 16 according to some embodiments of the present disclosure.

[0030] [Figure 18] FIG. 18 diagrammatically illustrates a fragmentation device of the apparatus of FIG. 16, according to some embodiments of the present disclosure.

[0031] [Figure 19] FIG. 19 diagrammatically illustrates an ionization chamber of the apparatus of FIG. 16 according to some embodiments of the present disclosure.

[0032] [Figure 20] FIG. 20 diagrammatically illustrates a growth chamber of the apparatus of FIG. 16 according to some embodiments of the present disclosure.

[0033] [Figure 21]FIG. 21 is a flow chart of a process for producing gallium nitride block crystals according to some embodiments of the present disclosure.

[0034] [Figure 22] FIG. 22 diagrammatically illustrates a horizontal apparatus for producing block crystals of a compound, according to some embodiments of the present disclosure.

[0035] [Diagram 23] FIG. 23 diagrammatically illustrates a smelting furnace of the apparatus of FIG. 22 according to some embodiments of the present disclosure.

[0036] [Figure 24] FIG. 24 diagrammatically illustrates a fragmentation device of the apparatus of FIG. 22, according to some embodiments of the present disclosure.

[0037] [Diagram 25] FIG. 25 diagrammatically illustrates an ionization chamber of the apparatus of FIG. 22 according to some embodiments of the present disclosure.

[0038] [Figure 26] FIG. 26 diagrammatically illustrates a growth chamber of the apparatus of FIG. 22 according to some embodiments of the present disclosure.

[0039] [Figure 27] FIG. 27 is a flow chart of a process for producing silicon carbide block crystals according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] (Detailed Description) While various embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It is understood that various alternatives to the embodiments of the invention described herein may be employed.

[0041] Whenever the terms "at least," "greater than," or "greater than or equal to" precede the first number in a series of two or more numbers, the terms "at least," "greater than," or "greater than or equal to" apply to each and every number in the series. For example, "greater than or equal to 1, 2, or 3" is equivalent to "greater than or equal to 1," "greater than or equal to 2," or "greater than or equal to 3."

[0042] Whenever the term "less than", "less than", or "less than or equal to" precedes the first number in a series of two or more numbers, the term "less than", "less than", or "less than or equal to" applies to each and every number in the series. For example, "less than or equal to 3, 2, or 1" is equivalent to "less than or equal to 3", "less than or equal to 2", or "less than or equal to 1".

[0043] FIG. 1 is a flow chart of a process for producing block crystals of metal compounds according to some embodiments of the present disclosure. In operation 101, a source metal is placed in a high temperature container. Air from the container may be evacuated to form a full or partial vacuum. The source metal may then be heated to a liquid state and maintained at a certain temperature to promote smooth flow. In some cases, after evacuation of the air from the container, the container may be filled with an inert gas to prevent contamination of the liquid metal (e.g., with air or other impurities). The inert gas may be helium, nitrogen, argon, or the like.

[0044] The source metal may be a metal with a high purity, such as gallium, aluminum, silicon, or a combination thereof. The temperature of the container may be above the melting point of the source metal when it is a single pure metal, i.e., if the source metal is a combination of metals, the temperature of the container may be above the melting point of the metal in the combination of metals with the highest melting point.

[0045] The high temperature container may be open and centered at the bottom of the smelting furnace with the top of the smelting furnace sealing the container from the outside environment, or alternatively, the high temperature container may have its own seal.

[0046] In operation 102, the liquid metal is caused to form a thin liquid metal stream. The thin liquid metal stream is then fragmented in a multi-step process to generate solvent-free, fine or ultrafine (nanoscale) metal particles. The multi-step fragmentation may include atomization and vaporization of the liquid metal stream. The atomization and vaporization can be performed separately, sequentially, or in a single integrated step.

[0047] Atomization may be performed using high pressure gas, mechanical vibrators with certain frequencies, or ultrasonic atomizers. Atomization may be performed by a single device, by multiple devices in series, or by multiple devices working together. Generally, gas atomization can generate particles with an average particle size of 30-50 μm. Ultrasonic atomization can generate particles with an average particle size of 10-20 μm. Both can also generate particles with smaller sizes of 100-500 nm at 0.4-0.6 kg / h, which accounts for less than 2-3% of the total weight. Water vaporization may be performed using induction heaters, DC arc water vaporizers, microwave sources, plasma sources, or laser water vaporizers. Water vaporization results in evaporated micro- and micro-nano metal particles under high temperatures. Water vaporization devices (such as plasmas with temperatures above 10,000° C.) can only act on metal particles with sizes less than 10 μm and break them down into particles with sizes of 10-100 nm. Otherwise it does not break them down at all but results in a hard shell from the surface reaction that can be difficult to break down, however the cost of plasma is high.

[0048] In operation 103, ultrafine metal particles are introduced into the ionization chamber. The temperature of the ionization chamber is set to be above the decomposition temperature of the metal and to promote further ionization of the ultrafine particles, while due to the high temperature, the formation of metal compounds (polycrystals) in the ionization chamber is avoided or reduced.

[0049] In operation 103, an inert gas (e.g., helium, nitrogen, or argon) is introduced to mix and agitate with the ionized metal particles so that the particles are homogenized, i.e., the inert gas is rotated, blown, and swept along the inner walls of the ionization chamber to avoid or reduce adhesion of the particles on the inner walls. Driven by the inert gas, the ionized metal particles collide with each other and become smaller so that more ionized metal particles are generated. Agglomeration and accumulation of the ionized metal particles in the ionization chamber is minimized by the constant movement of the particles.

[0050] In operation 104, the ionized metal particles diffuse from the ionization chamber, which has a high concentration of particles at a high temperature, to the growth chamber, which has a lower concentration of particles at a lower temperature. After diffusion, the ionized metal particles are uniformly distributed in the lower part of the growth chamber, slowly fall, accumulate, react with the non-catalyst reactive gas, and grow in the circular groove at a suitable temperature into a large cylindrical metal compound block crystal in the bottom of the growth chamber.

[0051] The apparatus and methods described in this disclosure can be adapted to produce many different types of block crystals by adjusting the reactant species, melting temperature, and environment within the ionization and growth chambers. Examples of block crystals produced using this method are metal nitrides, oxides, and carbides, and the like.

[0052] FIG. 2 diagrammatically illustrates a smelting furnace 1110 according to some embodiments of the present disclosure. The smelting furnace 1110 includes a vacuum crucible / container 1111 for holding source metal, a vacuum exhaust channel 1112, a gas channel 1113, and a redirection pipe 1114 for a thin liquid metal stream. The vacuum crucible / container 1111 is open at the top. The vacuum exhaust channel 1112 and the gas channel 1113 are located above the top of the smelting furnace 1110. The vacuum exhaust channel 1112 can use negative pressure to remove air from the vacuum crucible / container 1111 to generate a full or partial vacuum. The gas channel 1113 can introduce an inert gas into the vacuum crucible / container 1111. The redirection pipe 1114 is connected to the bottom of the vacuum crucible / container 1111. The opposite end of the redirection pipe 1114 can be connected to a fragmentation device.

[0053] FIG. 3 diagrammatically illustrates an alternative embodiment of a smelting furnace. The smelting furnace 1120 of FIG. 3 includes a vacuum crucible / container 1121 for holding source metal, a vacuum exhaust channel 1122, a gas channel 1123, and a redirection pipe 1124 for a thin liquid metal stream. The vacuum crucible / container 1111 is sealed at the top. The vacuum exhaust channel 1122 and the gas channel 1123 are located above the top of the vacuum crucible / container 1121, and the redirection pipe 1124 is connected to the bottom of the vacuum crucible / container 1121. The opposite end of the redirection pipe 1124 may be connected to a fragmentation device.

[0054] 4 diagrammatically illustrates a first fragmentation device 1210 according to some embodiments of the present disclosure. The first fragmentation device 1210 includes a collection tank 1211, an outlet 1212 for ultrafine metal particles, an atomization device 1213, a particle selector 1214, and an ejection port 1215 for coarse droplets. The particle selector 1214 may be configured to allow particles of a certain size to pass therethrough (e.g., about 500 nm or less for at least 85% of the particles passing through the particle selector 1214). In some embodiments, the particles are dispersed within the first fragmentation device such that smaller (and lighter) particles may be primarily retained (or suspended) in an upper portion of the first fragmentation device 1210, while larger (and heavier) particles may be primarily retained (or suspended) in a lower portion of the first fragmentation device 1210. In some embodiments, the particle selector 1214 applies a pressure differential between at least a majority of the first fragmentation device 1210 and the outlet 1212 around the inlet of the outlet 1212 such that particles with a predetermined particle size are allowed to pass through the particle selector 1214 and enter the outlet 1212. In some embodiments, the pressure differential and / or the location of the particle selector 1214 (e.g., there may be multiple outlets 1212 and their corresponding particle selectors 1214 distributed vertically along a sidewall of the first fragmentation device, or different first fragmentation devices 1210 may have different locations for the outlets 1212 and their corresponding particle selectors 1214 relative to the bottom of the first fragmentation device 1210) can be adjusted to allow different size ranges of particles to pass through the particle selector 1214. In some embodiments, the particle selector may comprise a plurality of angled gas holes, the orientation of which may inject the inert gas along the path of the outlet 1212 and away from the first fragmentation device 1210. In some embodiments, the plurality of angled holes may be oriented away from the fragmentation device. In some embodiments, the motive force caused by the inert gas injected through the plurality of angled holes creates a pressure differential such that particles of a predetermined size may be pushed into the outlet 1212.In some embodiments, the plurality of holes may be connected to an inert gas source. In some embodiments, the particle selector 1214 is configured to select particles whose size is about 1, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, or 500 nm or less. In some embodiments, for each selected range of particle sizes, particles having the selected range of particle sizes are at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% of the particles passing through the particle selector 1214. Particles that are too large to pass through the particle selector 1214 may eventually fall to the bottom of the first fragmentation device 1210 and pass through the discharge port 1215. Such particles may be reused later. An outlet 1212 is located on the side of the collection tank 1211, an atomization device 1213 is located on the top of the collection tank 1211, a particle selector 1214 is located on or embedded in the inner wall of the outlet 1212, and an ejection port 1215 for coarse metal droplets is located on the bottom of the collection tank 1211.

[0055] FIG. 5 diagrammatically illustrates a second embodiment of the fragmentation device 1220. The second fragmentation device 1220 includes a collection tank 1221, an outlet 1222 for micro-nano metal particles, an atomization device 1223, a water vaporization device 1224, and a discharge port 1225 for coarse metal droplets. The outlet 1222 for micro-nano metal particles is located on the side of the collection tank 1221 of the metal liquid, the atomization device 1223 is located on the top of the collection tank 1221, the water vaporization device 1224 is connected to the outlet 1222 for micro-nano metal particles, and the discharge port 1225 for coarse metal droplets is located on the bottom of the collection tank 1221 of the metal liquid. The atomization device may be used first. Then, particles with a size of less than 10 μm may be selected for water vaporization, and the coarser particles are left for re-atomization. Finally, the smaller selected particles may be directed to a water vaporization device by a pressure differential between the collection tank and the water vaporization device for further resolution into nanometer or atomic particles.

[0056] 6 diagrammatically illustrates a third embodiment of a fragmentation device 1230. The third fragmentation device 1230 includes an atomization device 1231 and a water vaporization device 1232. The atomization device 1231 and the water vaporization device 1232 may be connected in series or integrated to form the third fragmentation device 1230.

[0057] FIG. 7 diagrammatically illustrates an ionization chamber 1310 for generating ionized particles according to some embodiments of the present disclosure. The ionization chamber 1310 includes a liner 1311, an inlet 1312, an outlet 1313, an ion selector 1314, a particle rotation-suspension setup 1315, and an ejection port 1316 for coarse particles. The particle rotation-suspension setup 1315 may have a plurality of tilted and straight gas holes. In some embodiments, the plurality of tilted and straight gas holes may form a generally circular shape and are substantially uniformly distributed at the bottom of the ionization chamber 1310. In some embodiments, the plurality of tilted and straight gas holes may be distributed in a substantially alternating pattern. In some embodiments, the plurality of tilted and straight gas holes may be distributed such that one or more straight gas holes are followed by one or more tilted gas holes. In some embodiments, there may be a plurality of circular shapes or rings or strings of tilted and straight gas holes formed at the bottom of the ionization chamber. In some embodiments, at least a portion of the plurality of slanted and straight gas holes form a matrix at the bottom of the ionization chamber. The holes are located on the bottom of the ionization chamber or are embedded in a ring (or circular or irregular shape). As used herein, the term "straight gas hole" refers to a gas hole through which gas is injected into the ionization chamber in an upward manner, such as, for example, generally parallel to the central axis of the ionization chamber or the vertical sidewall of the ionization chamber. As used herein, the term "inclined gas hole" refers to a gas hole through which gas is injected into the ionization chamber at an angle (e.g., at least 10, 15, 20, 25, 30, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 degrees) relative to the central axis of the ionization chamber, or tilted above the central axis of the ionization chamber toward the bottom surface of the ionization chamber, or at an angle (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, or 25 degrees or less) relative to the bottom surface of the ionization chamber.Gas from the inclined holes blows and sweeps along the inner wall of the ionization chamber liner such that the particles are rotated from bottom to top with the gas flow, i.e., gas introduced by straight holes falls to the bottom of the ionization chamber, larger particles flow upwards such that they bounce up and down, collide with each other and break apart. The inlet 1312 of the ionization chamber 1311 is located on the top of the liner 1311, the outlet 1313 is located on the side of the liner 1311, the ion selector 1314 is embedded on the inner wall of the outlet 1313, the particle rotation-suspension setup 1315 is located around or embedded in the discharge port 1316 for coarse particles, which is located on the bottom of the liner 1311.

[0058] The ion selector 1314 may be configured to allow ions of a certain size to pass therethrough (eg, about 500 nm or smaller for at least 85% of the ions that pass through the ion selector 1314).

[0059] In some embodiments, the particles are dispersed within the ionization chamber 1310 such that smaller (and lighter) ions may reside (or be suspended) primarily in an upper portion of the ionization chamber 1310, while larger (and heavier) ions may reside (or be suspended) primarily in a lower portion of the ionization chamber 1310. In some embodiments, the ion selector 1314 applies a pressure differential between at least a majority of the ionization chamber 1310 and the outlet 1313 around an entrance to the outlet 1313 such that ions with a predetermined particle size are allowed to pass through the ion selector 1314 and enter the outlet 1313. In some embodiments, the pressure differential and / or the location of the ion selector 1314 (e.g., there may be multiple outlets 1313 and their corresponding ion selectors 1314 distributed vertically along the sidewall of the ionization chamber 1310, or different ionization chambers 1310 may have different locations for the outlets 1313 and their corresponding ion selectors 1314 relative to the bottom of the ionization chamber 1310) can be adjusted to allow different size ranges of ions to pass through the ion selector 1314. In some embodiments, the ion selector may comprise multiple angled gas holes, the orientation of which can inject inert gas along the path of the outlet 1313 and away from the ionization chamber 1310. In some embodiments, the multiple angled holes may point away from the ionization chamber 1310. In some embodiments, the driving force caused by the inert gas injected through the multiple angled holes creates a pressure differential such that ions of a predetermined size can be pushed into the outlet 1313. In some embodiments, the multiple holes may be connected to an inert gas source. In some embodiments, the ion selector 1314 is configured to select ions whose size is less than or equal to about 1, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, or 500 nm.In some embodiments, for each selected range of ion sizes, ions having the selected range of particle sizes are at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% of the particles passing through the ion selector 1314.

[0060] 8 diagrammatically illustrates a second embodiment of an ionization chamber for generating ionized particles. The ionization chamber 1320 includes a liner 1321, an inlet 1322, an outlet 1323, and a particle rotation-suspension setup 1324. The inlet 1322 is located above the top of the liner 1321, the outlet 1323 is located above the bottom of the liner 1321, and the particle rotation-suspension setup 1324 is located above or embedded in the bottom of the liner 1321.

[0061] 9 diagrammatically illustrates a third embodiment of an ionization chamber for generating ionized particles. The ionization chamber 1330 includes a liner 1331, an inlet 1332, an outlet 1333, a particle selector 1334, a particle rotation-suspension setup 1335, and an emission port 1336 for coarse particles. The inlet 1332 is located on the side of the liner 1331, the outlet 1333 is located on the top of the liner 1331, the particle selector 1334 is embedded on the bent part of the inner wall of the outlet 1333, the particle rotation-suspension setup 1335 is located around or embedded in the emission port 1336 for coarse particles, and the emission port 1336 for coarse particles is located on the bottom of the liner 1331.

[0062] 10 diagrammatically illustrates a fourth embodiment of an ionization chamber for generating ionized particles. The ionization chamber 1340 includes a liner 1341, an inlet 1342, an outlet 1343, and a particle rotation-suspension setup 1344. The inlet 1342 is located on a side of the liner 1341, the outlet 1343 is located on a bottom of the liner 1341, and the particle rotation-suspension setup 1344 is located around or embedded in the outlet 1343 on the bottom of the liner 1341.

[0063] 11 diagrammatically illustrates a fifth embodiment of an ionization chamber for generating ionized particles. The ionization chamber 1350 includes a liner 1351, an inlet 1352, an outlet 1353, a particle selector 1354, a particle rotation-suspension setup 1355, and an outlet port 1356 for coarse particles. The inlet 1352 is located on one side of the liner 1351, the outlet 1353 is located on another side of the liner 1351, the particle selector 1354 is embedded on the inner wall of the outlet 1353, the particle rotation-suspension setup 1355 is located around or embedded in the outlet port 1356 for coarse particles, and the outlet port 1356 for coarse particles is located on the bottom of the liner 1351.

[0064] 12 diagrammatically illustrates a sixth embodiment of an ionization chamber for generating ionized particles. The ionization chamber 1360 includes a liner 1361, an inlet 1362, an outlet 1363, a particle selector 1364, and a particle rotation-suspension setup 1365. The inlet 1362 is located on the bottom of the liner 1361, the outlet 1363 is located on the top of the liner 1361, the particle selector 1364 is located around or embedded in the outlet 1363, and the particle rotation-suspension setup 1365 is located around or embedded in the inlet 1362.

[0065] 13 diagrammatically illustrates a seventh embodiment of an ionization chamber for generating ionized particles. The ionization chamber 1370 includes a liner 1371, an inlet 1372, an outlet 1373, a particle selector 1374, and a particle rotation-suspension setup 1375. The inlet 1372 is located on the bottom of the liner 1371, the outlet 1373 is located on the side of the liner 1371, the particle selector 1374 is located around or embedded in the outlet 1373, and the particle rotation-suspension setup 1375 is located around or embedded in the inlet 1372 on the bottom of the liner 1371.

[0066] 14 diagrammatically illustrates a growth chamber 1410 for producing block crystals of metal compounds according to some embodiments of the present disclosure. The growth chamber 1410 includes a deposition-growth chamber 1411, an ion diffusion zone 1412, a crystal growth zone 1413, an inlet 1414 to the deposition-growth chamber 1411, an isolation grid 1415, a deposition-growth groove 1416, and a discharge port 1417 for excess gas.

[0067] The deposition-growth chamber 1411 is divided into two zones, namely, an ion diffusion zone 1412 and a crystal growth zone 1413. The ion diffusion zone 1412 is located in the upper part of the deposition-growth chamber 1411, and the crystal growth zone 1413 is located in the lower part of the deposition-growth chamber 1411, an inlet 1414 of the deposition-growth chamber is located on the top of the deposition-growth chamber 1411, and an isolation grid 1415 is set between the ion diffusion zone 1412 and the crystal growth zone 1413. The isolation grid 1415 can create a temperature difference between the ion diffusion zone 1412 and the crystal growth zone 1413 to enable uniform diffusion of particles. A deposition-growth groove 1416 is located above the bottom of the deposition-growth chamber 1411, and an outlet port 1417 for excess gas is located in the top of the deposition-growth chamber 1411.

[0068] 15 diagrammatically illustrates a second embodiment of a growth chamber for producing block crystals of metal compounds. The growth chamber 1420 includes a deposition-growth chamber 1421, an excess gas accumulation zone 1422, an ion diffusion zone 1423, a crystal growth zone 1424, an inlet 1425 to the deposition-growth chamber 1421, an isolation grid 1426 for excess gas, an isolation grid 1427, a deposition-growth groove 1428, and a discharge port 1429 for excess gas.

[0069] The deposition-growth chamber 1421 is divided into three zones: an excess gas accumulation zone 1422, an ion diffusion zone 1423, and a crystal growth zone 1424. The excess gas accumulation zone 1422 is located in an upper part of the deposition-growth chamber 1421, the ion diffusion zone 1423 is located in a central part of the deposition-growth chamber 1421, and the crystal growth zone 1424 is located in a lower part of the deposition-growth chamber 1421. An inlet 1425 of the deposition-growth chamber is located in the central part of the ion diffusion zone 1423 of the deposition-growth chamber 1421. An isolation grid 1426 for excess gas is set between the excess gas accumulation zone 1422 and the ion diffusion zone 1423, an isolation grid 1427 is set between the ion diffusion zone 1423 and the crystal growth zone 1424, a deposition-growth groove 1428 is located above the bottom of the deposition-growth chamber 1421, and a discharge port 1429 for excess gas is located at the top of the deposition-growth chamber 1421.

[0070] The smelting furnace, fragmentation device, ionization chamber, and growth chamber described above may be combined to form an apparatus for producing block crystals of a metal compound (eg, gallium nitride).

[0071] (Embodiment 1) FIG. 16 diagrammatically illustrates a vertical apparatus for producing block crystals of a compound (e.g., gallium nitride, aluminum nitride, or silicon carbide) according to some embodiments of the present disclosure. The description of FIG. 16 will specifically refer to gallium nitride, but one skilled in the art will understand that other compounds can also be formed using the apparatus. The apparatus of FIG. 16 includes a smelting furnace 210, a fragmentation device 220, an ionization chamber 230, and a growth chamber 240. The apparatus is a vertical structure, with the smelting furnace 210 above the fragmentation device 220, which is above the ionization chamber 230, which is above the growth chamber 240.

[0072] The gallium metal in the smelting furnace 210 is evacuated, heated, and liquefied into liquid metal such that the gallium liquid metal automatically flows or is directed into the fragmentation device 220 .

[0073] In the fragmentation device 220, the gallium liquid metal undergoes multiple fragmentation (atomization and steaming) procedures, gradually becoming fine and ultrafine gallium metal particles without the use of solvents, which then automatically enter or fall into the ionization chamber 230. Only particles below a certain size can enter the ionization chamber 230. Larger particles remain suspended at the bottom of the fragmentation device 220 and / or fall there and may be reused.

[0074] The temperature of the ionization chamber 230 may be set such that no gallium nitride polycrystals are formed and the ultrafine gallium metal particles are fully ionized. The fine and ultrafine gallium metal particles are thoroughly mixed and stirred with nitrogen and heated to form a uniform distribution of gallium ions.

[0075] A gas (e.g., nitrogen or argon) is pumped into the ionization chamber 230 to mix and stir with the ionized gallium particles so that the particles are homogenized. The gas is made to rotate from bottom to top to blow and sweep the inner wall of the liner of the ionization chamber 230 so as to reduce adhesion of the ionized gallium particles onto the inner wall of the liner. At the same time, the ionized gallium particles driven by the gas collide with each other and become smaller so that more ionized gallium particles are generated, i.e., the agglomeration and accumulation of the ionized gallium particles is thereby minimized.

[0076] Gallium ions are introduced into the growth chamber 240 and first enter the ion diffusion zone in the upper part of the growth chamber 240. Under the coordinated action of temperature difference, ion / particle concentration, and reactive gas flow, the gallium ions pass through the isolation grid between the ion diffusion and the crystal growth zone and enter the crystal growth zone in the lower part of the gallium nitride growth chamber 240. The temperature of the crystal growth zone is set within a range that is beneficial for the growth of gallium nitride crystals, i.e., the gallium ions are scattered and uniformly distributed in the crystal growth zone. Finally, the gallium ions slowly fall and accumulate, react with the uncatalyzed reactive gas (e.g., NH3), and grow in the deposition groove at the bottom of the growth chamber 240 to form a thick gallium nitride block crystal.

[0077] FIG. 17 diagrammatically illustrates the smelting furnace 210 of the apparatus of FIG. 16 according to some embodiments of the present disclosure. The smelting furnace 210 includes a vacuum crucible / container 211, a vacuum exhaust channel 212, a gas channel 213, and a redirection pipe 214. The smelting furnace 210 is sealed. The vacuum exhaust channel 212 and the gas channel 213 are located on the top of the smelting furnace 210 and the top is open, the vacuum crucible / container 211 is located centrally on the bottom of the smelting furnace 210, and a redirection pipe 214 for liquid metal gallium is connected to the bottom of the vacuum crucible / container 211. The opposite end of the redirection pipe 214 is connected to a fragmentation device 220.

[0078] 18 diagrammatically illustrates a fragmentation device 220 of the apparatus of FIG. 16 according to some embodiments of the present disclosure. The fragmentation device 220 includes an atomization device 221 and a water vaporization device 222. The atomization device 221 and the water vaporization device 222 are connected in series or integrated together to form the fragmentation device 220, which is embedded in the top of the ionization chamber 230.

[0079] Figure 19 diagrammatically illustrates an ionization chamber 230 of the apparatus of Figure 16 according to some embodiments of the present disclosure. The ionization chamber 230 includes a liner 231, an inlet 232, an outlet 233, and a rotation-suspension setup 234. The inlet 232 is located at the top of the liner 231, the outlet 233 is located in the bottom of the liner 231, and the rotation-suspension setup 234 is located or embedded in an upper corner of the bottom of the liner 231.

[0080] 20 diagrammatically illustrates a growth chamber 240 of the apparatus of FIG. 16 according to some embodiments of the present disclosure. The growth chamber 240 includes a deposition-growth chamber 241, a gallium ion diffusion zone 242, a growth zone 243, an inlet 244, an isolation grid 245, a deposition-growth groove 246, and an outlet port 247 for excess gas. The deposition-growth chamber 241 is divided into two zones, the gallium ion diffusion zone 242 and the growth zone 243. A gallium ion diffusion zone 242 is located in the upper part of the deposition-growth chamber 241, a growth zone 243 is located in the lower part of the deposition-growth chamber 241, an inlet 244 is located at the top of the deposition-growth chamber 241, an isolation grid 245 is set between the gallium ion diffusion zone 242 and the growth zone 243, a gallium nitride crystal deposition-growth groove 246 is located above the bottom of the deposition-growth chamber 241, and an emission port 247 is located on the top of the gallium nitride deposition-growth chamber 241.

[0081] FIG. 21 is a flow chart of a process for producing gallium nitride block crystals according to some embodiments of the present disclosure.

[0082] In operation 201, pure metallic gallium is placed in a vacuum crucible / container 211. The pure metallic gallium is evacuated, heated, and liquefied at a temperature above 29.78° C. The liquid metallic gallium is maintained at a specific temperature (above 29.78° C.) to maintain its fluidity, and an inert gas (helium, nitrogen, or argon) is used to prevent contamination of the pure metallic gallium with outside impurities.

[0083] In operation 202, liquid metallic gallium metal flows through a redirection pipe 214 to form a thin liquid stream. The liquid stream first enters an atomization device 221, which generates micro-sized gallium metal particles through high frequency vibration, ultrasound, or high pressure. The micro-sized gallium metal particles then enter a water vaporization device 222, which vaporizes the micro-sized gallium metal particles at temperatures above 4,000° C. The water vaporization process may be solvent-free.

[0084] In operation 203, the ultrafine gallium metal particles automatically fall into the ionization chamber liner 231. The temperature within the liner 231 is set above 1,300° C. so that gallium nitride polycrystals do not form and the ultrafine gallium metal particles are fully ionized.

[0085] A gas (e.g., nitrogen or argon) is then introduced through a rotating-suspension setup 234 to mix and agitate with the ionized gallium particles so that the particles are homogenized. The gas is rotated from bottom to top to blow and sweep the inner wall of the liner 231 so as to reduce adhesion of the ionized gallium particles to the inner wall of the liner 231. At the same time, the ionized gallium particles driven by the gas collide with each other and become smaller. In this way, the aggregation and accumulation of the ionized gallium particles is reduced.

[0086] In operation 204, ionized gallium particles enter a gallium ion diffusion zone 242 in an upper portion of a deposition-growth chamber 241 through an inlet 244. The deposition-growth chamber 241 contains two zones, a gallium ion diffusion zone 242 and a growth zone 243, in which the temperature is adjusted and controlled at different time periods. A reactive gas (e.g., ammonia) is introduced into the growth zone 242. The deposition time of the gallium nitride is determined by the required thickness of the gallium nitride crystal.

[0087] Under the coordinated action of temperature difference, ion / particle concentration, and reactive gas flow, the ionized gallium particles pass through the isolation grid 245, diffuse uniformly, and enter the growth zone 243 in the lower part of the deposition-growth chamber 241. The diffusion rate of the ionized gallium particles is reduced, i.e., the particles are uniformly distributed in the growth zone 243 located in the lower part of the deposition-growth chamber 241. Finally, the ionized gallium particles slowly fall and react with non-catalyst reactive gas (e.g., nitrogen / N2, ammonia / NH3) and grow in the deposition groove above the bottom of the deposition-growth chamber 241, which has a suitable temperature to form a thick large cylindrical gallium nitride block crystal.

[0088] The temperature in the gallium ion diffusion zone 242 is controlled and adjusted at different time periods, namely, 1,200-1,300°C during gallium ion introduction and crystal growth, and 800-1,200°C during the evolution of excess gases (H2 and N2).

[0089] The reaction temperature for gallium nitride in the growth zone 243 is set at 900-1,200° C., and the reaction equation is:

[0090] 2Ga+N2=2GaN

[0091] 2Ga+2NH3=2GaN+3H2

[0092] The excess gases (hydrogen and nitrogen) automatically rise due to their own weight. They flow upward, pass through the isolation grid 245 and enter the gallium ion diffusion zone 242. After a period of time, the excess gases are released through the release port 247 in the growth chamber above the top of the deposition-growth chamber 241.

[0093] (Embodiment 2) 22 diagrammatically illustrates a horizontal apparatus for producing block crystals of a compound (e.g., gallium nitride, aluminum nitride, or silicon carbide) according to some embodiments of the present disclosure. The description of FIG. 22 will specifically refer to silicon carbide, but one of ordinary skill in the art will understand that other compounds can also be formed using the present apparatus.

[0094] As shown in Figure 22, the apparatus includes a smelting furnace 310, a fragmentation device 320, an ionization chamber 330, and a growth chamber 340. The apparatus in Figure 22 is a vertical-horizontal mixed structure. The smelting furnace 310 is located above the fragmentation device 320, the ionization chamber 330 is located beside the fragmentation device 320, and the growth chamber 340 is located beside the ionization chamber 330.

[0095] The silicon metal in the smelting furnace 310 is placed under vacuum, heated, and liquefied such that the silicon liquid metal automatically flows into the fragmentation device 320 to form liquid metal.

[0096] In the fragmentation device 320, the atomization device and the water vaporization device are used separately to treat the silicon metal. The silicon liquid metal is first subjected to atomization to form micro- and micro-nano-scale silicon particles. The micro-nano-scale silicon particles are selected for water vaporization treatment to become ultra-fine silicon metal particles, while the larger micro-silicon particles are left behind and collected together for reuse. The ultra-fine silicon metal particles are directed through the water vaporization device to the ionization chamber 330.

[0097] The temperature of the ionization chamber 330 is set above the decomposition temperature of silicon carbide so that no silicon carbide polycrystals are formed and the ultra-fine silicon metal particles are fully ionized.

[0098] A gas (e.g., nitrogen) is introduced into the ionization chamber 330 to mix and stir with the ionized silicon particles so that the particles are homogenized. The gas is rotated from bottom to top to blow and sweep the inner wall of the liner of the ionization chamber 330 so as to reduce adhesion of the ionized silicon particles to the inner wall of the liner of the ionization chamber 330. At the same time, the ionized silicon particles driven by the gas collide with each other and become smaller so that additional smaller ionized silicon particles are generated, i.e., the agglomeration and accumulation of the ionized silicon particles is thereby reduced.

[0099] Through particle selection-orientation setting on the top of the ionization chamber 330, the ionized silicon particles are directed into the growth chamber 340. First, the particles enter the ion diffusion zone in the middle part of the growth chamber 340 and are induced to diffuse uniformly. Under the coordinated action of temperature difference, ion / particle concentration, and reactive gas flow, the ionized silicon particles fall into and pass through the isolation grid between the ion diffusion and crystal growth zones and enter the crystal growth zone in the lower part of the growth chamber 340. The temperature in the crystal growth zone is set to be beneficial for the growth of silicon carbide crystals. After the ionized silicon particles pass through the isolation grid between the ion diffusion zone and the crystal growth zone, they diffuse to the periphery of the crystal growth zone in the lower part of the growth chamber 340, slowly fall, accumulate, react with the uncatalyzed reactive gas, and grow in the deposition groove above the bottom of the growth chamber 340 at a suitable temperature to form a thick large high purity silicon carbide block crystal.

[0100] FIG. 23 diagrammatically illustrates a smelting furnace 310 of the apparatus of FIG. 22 according to some embodiments of the present disclosure. The smelting furnace 310 includes a vacuum crucible / container 311, a vacuum exhaust channel 312, a gas channel 313, and a liquid redirection pipe 314. The vacuum exhaust channel 312 and the gas channel 313 are located above the top of the vacuum crucible / container 311. The vacuum exhaust channel 312 can remove air from the vacuum crucible / container 311 to generate a vacuum. The gas channel 313 can introduce non-reactive gases into the vacuum crucible / container 311. One end of the redirection pipe 314 is connected to the bottom of the vacuum crucible / container 311, and the other end is directly connected to the fragmentation device 320.

[0101] 24 diagrammatically illustrates a fragmentation device 320 of the apparatus of FIG. 22 according to some embodiments of the present disclosure. The fragmentation device 320 includes a collection tank 321, an outlet 322 for micro-nano sized silicon particles, a mist device 323, a water vaporization device 324, a particle selector 325, and a discharge port 326. Through a redirection pipe 314, the top of the collection tank 321 is connected to the bottom of the vacuum crucible / container 311. The outlet 322 for micro-nano sized silicon particles is located on the side of the collection tank 321. The mist device 323 and the water vaporization device 324 are located separately. The atomization device 323 is embedded in the top of the collection tank 321, the water vaporization device 324 is connected to the outlet 322 for the micro-nano sized silicon particles, the particle selector 325 is embedded on the inner wall of the outlet 322 for the micro-nano sized silicon particles, and the discharge port 326 is located at the bottom of the collection tank 321.

[0102] FIG. 25 diagrammatically illustrates an ionization chamber 330 of the apparatus of FIG. 22 according to some embodiments of the present disclosure. The ionization chamber 330 includes a liner 331, an inlet 332, an outlet 333, a particle selector 334, a particle rotation-suspension setup 335, and an ejection port 336 for coarse particles. The inlet 332 is located in the central part of the liner 331, the outlet 333 is located on the top of the liner 331, and the particle selector 334 consists of a plurality of oblique holes, which are uniformly distributed and formed into a ring, located above the outlet 333. The oblique holes are embedded in the inner wall of the corner of the channel between the ionization chamber 330 and the growth chamber 340. The particle rotation-suspension setup 335 consists of several oblique and straight holes, which are uniformly distributed and form a ring, embedded above the bottom of the liner 331 and around the discharge port 336, which is located in the center of the bottom of the liner 331.

[0103] FIG. 26 diagrammatically illustrates a growth chamber 340 of the apparatus of FIG. 22 according to some embodiments of the present disclosure. The growth chamber 340 includes a deposition-growth chamber 341, an excess gas accumulation zone 342, a silicon ion diffusion zone 343, a growth zone 344, an inlet 345, an isolation grid 346, an isolation grid 347, a deposition-growth groove 348, and an outlet port 349 for excess gas. The deposition-growth chamber 341 is divided into three zones: the excess gas accumulation zone 342, the silicon ion diffusion zone 343, and the growth zone 344. The excess gas accumulation zone 342 is located in the upper part of the deposition-growth chamber 341, the silicon ion diffusion zone 343 is located in the middle of the deposition-growth chamber 341, and the growth zone 344 is located in the lower part of the deposition-growth chamber 341. The inlet 345 is located in the silicon ion diffusion zone 343. An isolation grid 346 is set between the excess gas accumulation zone 342 and the silicon ion diffusion zone 343, an isolation grid 347 is set between the silicon ion diffusion zone 343 and the growth zone 344, a deposition-growth groove 348 is located in the bottom of the deposition-growth chamber 341, and a discharge port 349 for excess gas in the silicon carbon growth chamber is located at the top of the deposition-growth chamber 341.

[0104] FIG. 27 is a flow chart of a process for producing silicon carbide block crystals according to some embodiments of the present disclosure.

[0105] In operation 301, pure metallic silicon is introduced into a vacuum crucible / container 311, placed under vacuum, heated, and liquefied at a high temperature of 1,410° C. or above. The liquid metallic silicon is maintained at a specific temperature (above 1,410° C.) to maintain better fluidity, and an inert gas (e.g., helium, nitrogen, or argon) is used to protect the silicon from contamination with external impurities.

[0106] In operation 302, liquid metal silicon is atomized and vaporized in separate steps. The liquid metal silicon enters the atomization device 323 for atomization, resulting in micro- and micro-nano-scale silicon particles. The particle selector 325 allows particles that are small enough to enter the water vaporization device 324, which vaporizes the particles at temperatures above 4,000° C., to become ultra-fine silicon metal particles, i.e., larger silicon particles are left behind and fall to the bottom of the collection tank 321, where they are collected together and collected through the discharge port 326 for reuse. By using the water vaporization device 324, the ultra-fine silicon metal particles are automatically directed toward the inlet 332 of the ionization chamber.

[0107] In operation 303, ultrafine silicon metal particles enter the ionization chamber liner 331. The temperature within the liner 331 is set above 2,600° C. so that silicon carbon polycrystals do not form and the ultrafine silicon metal particles are fully ionized.

[0108] The heavier particles fall to the bottom of the ionization chamber liner 331. The inert gas (e.g., helium, nitrogen, or argon) introduced from the particle rotation-suspension setup 335 rotates, blows, and sweeps the heavier silicon particles along the inner wall of the ionization chamber liner 331 so as to reduce the adhesion of the ionized silicon particles to the inner wall of the liner 331. Meanwhile, driven by the gas, the ionized silicon particles collide with each other and become smaller. In this way, the aggregation and accumulation of the ionized silicon particles is also reduced.

[0109] The ionized silicon particles are introduced into the deposition-growth chamber 341 through the outlet 333. A particle selector 334 allows only particles of a sufficiently small size to enter the deposition-growth chamber 341. After a certain period of time, larger silicon particles that cannot enter the deposition-growth chamber 341 due to their own weight are left on the bottom of the ionization chamber liner 331 and are discharged through the discharge port 336.

[0110] In operation 304, ionized silicon particles are directed into a silicon ion diffusion zone 343 in the central portion of a deposition-growth chamber 341. The deposition-growth chamber 341 contains three regions, namely, an excess gas accumulation zone 342, a silicon ion diffusion zone 343, and a growth zone 344, in which the temperature is adjusted and controlled at different time periods. The silicon carbide deposition-growth time is determined by the required thickness of the silicon carbide crystals.

[0111] Under the coordinated action of temperature difference, ion / particle concentration, and reactive gas flow, the ionized silicon particles diffuse through the isolation grid 347 and enter the growth zone 344 in the lower part of the deposition-growth chamber 341. The ionized silicon particles are uniformly distributed in the growth zone 344 in the lower part of the deposition-growth chamber 341. Finally, the ionized silicon particles fall, accumulate, react with the uncatalyzed reactive gas (CH4), and grow in the circular deposition-growth groove 348 under suitable temperature to form large high purity cylindrical silicon carbide block crystals.

[0112] The temperature of the excess gas accumulation zone 342 is controlled and adjusted at different time periods, i.e., above 2,500°C during silicon ion introduction and crystal growth, and 1,600-2,100°C during excess gas (H2 and N2) release. During silicon ion introduction and crystal growth, the excess gas accumulation zone 342 maintains a higher temperature for a higher temperature difference or gradient with respect to the growth zone so that ions are diffused into the growth zone. Otherwise, ions will rise into the excess gas accumulation zone. After the crystal growth cycle is finished, the excess gas (H2 and N2) is required to be released, and the temperature of the excess gas accumulation zone is reduced so that lighter gases rise to release. The temperature in the silicon ion diffusion zone 343 is controlled and adjusted as follows, i.e., 2,300-2,600°C during silicon ion introduction and crystal growth, and 1,600-2,100°C during excess gas (H2 and N2) release.

[0113] The reaction temperature for silicon carbide in the growth zone 344 is set at 1,800-2,500° C. and the reaction equation is:

[0114] Si+CH4=SiC+2H2

[0115] The remaining or excess gases (H2 and N2) will automatically rise due to their lighter weight. They will flow upward through isolation grid 347 and isolation grid 346 and enter the excess gas accumulation zone 342. After a period of time, the remaining or excess gases will be released through the release port 349 on the top of the deposition-growth chamber 341.

[0116] (Conclusion) The method and device described herein can be easily modified for the production of different compound block crystals, such as nitrogen, oxygen, and carbon-based compounds, by switching the source metal and reactive gas employed. In addition, the main characteristic of the method is to form metal compound bulk crystals without solvents and catalysts using physical means (e.g., mechanical force / energy) under the combined action of thermal energy, kinetic energy, and reaction time. An additional characteristic of the method is to break the liquid stream into particles of the source metal using high pressure gas (e.g., helium, nitrogen, or argon), and optionally apply ultrasound to the liquid stream and / or mechanically vibrate it to further break down the liquid stream or larger particles of the source metal without the use of solvents or chemical means. A further additional characteristic of the method is to insert a particle selector between the atomization device and the water vaporization device so that particles of a predetermined size can be transported from the fragmentation device to the ionization chamber, and an ion selector between the ionization chamber and the growth chamber so that ions of a predetermined size can be transported from the ionization chamber to the growth chamber. An additional feature of the method is that tilted holes (e.g., for particle selectors, ion selectors, and rotation-suspension setups) are used to inject inert gas along the interior walls of the device, chamber, or outlet, etc., to prevent or reduce particle or ion deposition or agglomeration, or adhesion of particles or ions to the device, chamber, or outlet, respectively.

[0117] While preferred embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the present invention be limited by the specific examples provided herein. The present invention has been described with reference to the foregoing specification, but the description and illustration of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the present invention. Furthermore, it should be understood that all aspects of the present invention are not limited to the specific depictions, configurations, or relative proportions described herein, which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the present invention described herein may be employed in practicing the present invention. It is therefore contemplated that the present invention also covers any such alternatives, modifications, variations, or equivalents. It is intended that the following claims define the scope of the present invention, and that methods and structures within the scope of these claims and their equivalents are covered thereby.

Claims

1. A method for forming block crystals of a metal compound, comprising: (a) introducing a source metal into a smelting furnace; (b) forming a complete or partial vacuum in the smelting furnace, increasing the temperature of the smelting furnace above the melting point of the source metal to form a liquid stream of the source metal; (c) decomposing the liquid stream to generate particles of the source metal; (d) ionizing the particles in an ionization chamber to form ionized particles, wherein the temperature of the ionization chamber is above the decomposition temperature of the metal compound; and (e) introducing the ionized particles into a growth chamber comprising a reactive gas that is reactive with the ionized particles, thereby forming the block crystals of the metal compound. A method comprising the above steps.

2. (i) (c) includes one or more of: (1) applying a high-pressure gas to the liquid stream, (2) applying ultrasonic waves to the liquid stream, or (3) mechanically vibrating the liquid stream; or (ii) (c) includes (1) applying a high-pressure gas to the liquid stream and (2) applying ultrasonic waves; or (iii) (c) includes (1) applying a high-pressure gas to the liquid stream and (2) mechanically vibrating the liquid stream; or (iv) (c) includes (1) applying a high-pressure gas to the liquid stream, (2) applying ultrasonic waves to the liquid stream, and (3) mechanically vibrating the liquid stream. The method according to claim 1.

3. (i) (d) includes introducing a flow of an inert gas into the ionization chamber to thereby prevent (1) agglomeration of the ionized particles and (2) adhesion of the ionized particles to the ionization chamber; or (ii) (b) includes introducing another inert gas into the smelting furnace following the formation of the complete or partial vacuum in the smelting furnace; or (iii) removing a subset of the particles larger than a threshold size prior to reaching the ionization chamber following (c); or (iv) (c) includes atomizing and vaporizing the liquid stream; or (v) (c) is carried out without a solvent. The method according to claim 1. **Claim 4** (i) Each of the high-pressure gas, the inert gas, and the another inert gas is independently helium, nitrogen, or argon, or, (ii) The subset of the particles is reused, The method according to claim 3. **Claim 5** (i) The ionized particles diffuse from the ionization chamber to the growth chamber along a concentration gradient or a temperature gradient, or, (ii) The block crystal of the metal compound is formed in a deposition groove at the bottom of the growth chamber, or, (iii) The temperature of the growth chamber promotes the growth of the block crystal of the metal compound, or, (iv) The reactive gas is catalyst-free, or, (v) The source metal is gallium, aluminum, indium, silicon, or a combination thereof, The method according to claim 1. **Claim 6** (i) The source metal is a pure metal, or, (ii) The source metal is a combination of metals, The method according to claim 1. **Claim 7** (b) includes increasing the temperature of the blast furnace above the melting point of the metal with the highest melting point in the combination of metals, the method according to claim 6. **Claim 8** (i) The source metal is gallium, the reactive gas is nitrogen or ammonia, and the metal compound is gallium nitride, or, (ii) The source metal is aluminum, the reactive gas is nitrogen or ammonia, and the metal compound is aluminum nitride, or, (iii) The source metal is silicon, the reactive gas is methane, and the metal compound is silicon carbide, or, (iv) The source metal is indium, the reactive gas is nitrogen or ammonia, and the metal compound is indium nitride, The method according to claim 1. **Claim 9** An apparatus for forming a block crystal of a metal compound, comprising A blast furnace configured to heat a source metal and form a liquid stream of the source metal, A fragmentation device coupled to the blast furnace, the fragmentation device being configured to generate particles of the source metal from the liquid stream, An ionization chamber coupled to the fragmentation device, the ionization chamber being configured to ionize the particles and form ionized particles, A growth chamber coupled to the ionization chamber, the growth chamber being configured to promote growth of the block crystals of the metal compound through a reaction between the ionized particles and a reactive gas within the growth chamber, the growth chamber and An apparatus comprising. **Claim 10**: (i) The fragmentation device comprises one or more atomization devices and a vaporization device, or (ii) The one or more atomization devices comprise a gas nebulizer, a mechanical vibrator, or an ultrasonic nebulizer, or (iii) The fragmentation device comprises one or more atomization devices and a vaporization device, and the apparatus further comprises a particle selector disposed between the one or more atomization devices and the vaporization device, or (iv) The apparatus further comprises an ion selector disposed between the ionization chamber and the growth chamber, or (v) The ionization chamber comprises a particle rotation-suspension setting disposed on a bottom portion of the ionization chamber, the particle rotation-suspension setting being configured to generate a plurality of upward inert gas flows introduced by a plurality of straight holes and a plurality of inclined inert gas flows introduced by a third plurality of inclined holes, The apparatus according to claim 9. **Claim 11**: (i) The particle selector comprises a first plurality of inclined gas holes, or (ii) The one or more atomization devices comprise a gas nebulizer, a mechanical vibrator, or an ultrasonic nebulizer, or (iii) The ion selector comprises a second plurality of inclined gas holes, or (iv) The plurality of straight holes and the third plurality of inclined holes are (1) substantially dispersed in a circular shape or an irregular shape, (2) intersected with each other or in a substantially alternating pattern, or (3) substantially uniformly dispersed at the bottom of the ionization chamber, The apparatus according to claim 10. **Claim 12** The apparatus according to claim 9, wherein the blast furnace comprises a crucible configured to hold the source metal. **Claim 13**: (i) The crucible is sealed, or (ii) The crucible is open to the blast furnace, or (iii) The smelting furnace is provided with a vacuum exhaust channel, and the vacuum exhaust channel is configured to remove air from the crucible or the smelting furnace or both, and to form a complete or partial vacuum in the crucible or the smelting furnace, or (iv) The smelting furnace is provided with a gas channel configured to supply an inert gas to the crucible or the smelting furnace or both, or (v) The vacuum exhaust channel or the gas channel is disposed in an upper portion of the crucible or an upper portion of the smelting furnace, The apparatus according to claim 9.

14. (i) Further comprising a direction conversion channel for coupling the smelting furnace to the fragmentation device, or (ii) The one or more atomization devices and the vaporization device are connected in series, or integrated together, or (iii) The one or more atomization devices are a plurality of atomization devices, and the plurality of atomization devices are connected in series, or integrated together, or (iv) The vaporization device comprises an induction heater, a DC arc, a plasma source, a microwave source, or a laser, or (v) The growth chamber comprises a deposition-growth chamber, or (vi) The fragmentation device is coupled to a bottom portion of the smelting furnace, the ionization chamber is coupled to a side surface of the fragmentation device, and the growth chamber is coupled to an upper portion of the ionization chamber, or (vii) The ionization chamber is provided with a discharge port for coarse particles, and the discharge port is disposed in a bottom portion of the ionization chamber, The apparatus according to claim 9.

15. The deposition-growth chamber comprises an upper ion diffusion zone, a bottom growth zone, and an isolation grid disposed between the ion diffusion zone and the growth zone, the apparatus according to claim 14.

16. The isolation grid comprises a plurality of holes allowing diffusion of the ionized particles, the apparatus according to claim 15.

17. The bottom growth zone comprises a circular deposition groove for growing the block crystal of the metal compound, the apparatus according to claim 15.

18. The growth chamber includes a deposition-growth chamber, and the deposition-growth chamber includes an upper gas accumulation zone, a central ion diffusion zone, a bottom growth zone, a first isolation grid disposed between the central ion diffusion zone and the bottom growth zone, and a second isolation grid disposed between the upper gas accumulation zone and the central ion diffusion zone. The apparatus according to claim 9.

19. The inlet to the deposition-growth chamber is within the central ion diffusion zone. The apparatus according to claim 18.

20. The upper gas accumulation zone includes an excess gas discharge port. The apparatus according to claim 18.

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