JPH0764534B2 - Magnetohydrodynamic apparatus and method for material separation and deposition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Separation of materials can be accomplished by exerting or exerting a force on the native species of the material or the species of the compound of the material. These forces are gravity, electromagnetic forces, gas (fluid) powers and / or combinations of these forces. These forces give different accelerations to the species, which give different spatial and temporal properties for the desired separation. The material could be in the solid, liquid, vapor or plasma states, or a combination thereof. Magnetohydrodynamic method (magnetoplsmadynamic process
ss) includes each or a combination of these conditions.

The magnetohydrodynamic phenomenon was first discovered by cann in 1961 and described in US Pat. No. 3,243,954. The designed and tested device is intended for space propulsion applications and is commonly known as an ion propulsion system. The main design and performance requirements have been to completely ionize a single species of vapor and accelerate all ions into space at the desired high velocity. The device must have a high thrust efficiency, where the thrustor efficiency is defined as: No attempt was made to separate the material in this way. The intended application was not directed to the development of that purpose.

Magnetohydrodynamic phenomena consist of the controlled interaction of a plasma with an induced magnetic field that occurs when the plasma is accelerated by an applied electrostatic field (potential). This type of interaction phenomenon is hereafter referred to as the Hall current effect (Ha
ll Current effect). The implication of the work of cann et al. Was the controlled injection of feed or propellant into the anode area of the cavity. Appropriate voltage selection and propellant injection rates are determined by the charged particles (ions and electrons) in a direction parallel to the applied magnetic field.
Resulting in ionization and acceleration of. The resulting plasma was accelerated to the desired exhaust velocity.

The present invention relates to separating materials by a new and improved method using magnetohydrodynamics.

The present invention allows for the separation and collection of materials that cannot otherwise be separated. It also separates materials that can be separated by other techniques or methods of the invention, but at a lower cost.

An important use of the method and apparatus of the present invention is the production of semiconductor grade silicon from low cost silicon compounds as feed materials. Semiconductor grade silicon is considered to be silicon made by refining techniques with a purity of at least 99.9999%. For efficient operation of silicon solar cells, semiconductor grade silicon is actually at least 99.999% pure, preferably at least 9%.
It should be 9.9999% pure. On the other hand, at least 97% pure silicon is considered metallurgical grade silicon. Commercially available metallurgical grade silicon is approximately 98% pure. Semiconductor grade silicon is significantly more costly than metallurgical grade silicon. In 1980, semiconductor grade silicon cost nearly $ 80 / kg, while metallurgical grade silicon costs less than $ 1 / kg.

Ironically, semiconductor grades are valuable because they are commonly used in products that require the addition of specified impurities or "dopants" to the silicon. These dopants affect the conductivity of the silicon, creating donor and receptor moieties for the semiconductor device. Therefore, "semiconductor grade silicon (se
"miconductor grade silicon)" as used herein should be taken to include highly pure silicon doped with dopants.

As mentioned above, semiconductor grade silicon is used in the manufacture of various semiconductor devices, such as silicon solar cells.
It is important to reduce solar cell manufacturing costs so that solar cell manufacturing is compensated for the expected life of the solar cell. Presently, silicon solar cells are made from a single crystal of n-type silicon with a diameter of about 4 cm and a length of about sausage. These crystals are made by spinning and pulling at a slow, coordinated pace.
The elongated crystals are then cut with a circular saw of diamond tips into slices approximately 50 microns thick. The slices are ground, lapped, chemically cleaned and placed in a diffusion chamber consisting of a long quartz tube moving through a cylindrical electric furnace. The crystals are heated to 1150 ° C. in an atmosphere of boron trichloride in a diffusion chamber. The elemental boron, which decomposes from the boron compound, diffuses into the outer surface of the silicon wafer, thus doping the wafer to create a p-type layer thinner than 0.3 microns. Further processing is required to make the terminals and expose the n-type silicon now sandwiched in the center.

Although this method is ideal for the manufacture of small electrical components, the process involved involves more than $ 12,000 per kilowatt of electric power producing solar panel panels, or (1973
Dollar). Although the ideal cost of manufacturing is expected to decrease with improvements in manufacturing technology and mass production,
The price is still orders of magnitude higher for solar panels used commercially for the production of electricity in non-remote areas such as spacecraft. Also, in many cases the energy consumed in production cannot be recovered from the expected life of the solar cell.

Several systems have been proposed for manufacturing semiconductor devices, such as solar cells, by other means. For example, US Pat. No. 4,003,770 (Janowieck, et al.) (Also United
States Patent Office Voluntary Protest Progra
m Document No. B 65105) discloses a method of making a solar cell which comprises injecting particles of p- or n-doped silicon into a plasma stream and evaporating the particles therein. The heated particles are then ejected from the plasma stream onto the substrate to form a polycrystalline silicon film. During heating and spraying, a suitable atmosphere is provided to surround the particles and prevent oxidation. However, U.S. Pat.
The issue does not suggest the use of this technique for silicon refining. U.S. Pat.No. 2,537,255 (Walter H. Bratt
ain) uses a mixture of hydrogen and silicon tetrachloride,
Disclosed is silicon deposition for a silicon glow emf battery. However, this earlier technique does not disclose the use of magnetohydrodynamic effects in both the fabrication of these solar cells and the refining of metallurgical grade silicon to semiconductor grade silicon.

U.S. Pat. No. 3,916,034 (Tsuchimoto) discloses a method of transferring a semiconductor in a plasma stream onto a substrate. The plasma is directed onto a thin film substrate by a magnetic field. U.S. Pat. No. 3,916,034 is representative of conventional magnetohydrodynamic methods. In the magnetohydrodynamic method, a large amount of utilization efficiency (mass utilza
Since its efficiency is low, this method is ineffective for refining a large amount of silicon.

It is also possible to create a deposition system using a magnetohydrodynamic arc, where the magnetic nozzle is created by a magnetic coil and / or the self-field of the discharge. This magnetic nozzle allows a high ion concentration in the plasma jet and a good distribution of silicon in the jet. The anode attachment can be diffused or rapidly rotated during electromagnetic (j × B) forces to uniformly erode the anode.
However, this system is "modal"
It provides performance, where small changes in mass flow rate critically affect the voltage requirements of this system. In this system, the insulator between the anode and cathode can be eroded or coated during operation of the plasma device to short circuit the discharge.

Accordingly, it is an object of the present invention to provide a method and apparatus for refining silicon, in particular for refining metallurgical grade silicon to a more pure form of silicon to produce semiconductor grade silicon. .

Another object of the invention is to provide a cheap base product for producing semiconductor grade materials in the form of large area thin films and thereby making silicon photovoltaic solar cells.

Yet another object of the present invention is to provide a method for purifying materials such as silicon using magnetohydrodynamic techniques.

Therefore, still another object of the present invention is to separate species by conventional chemical reduction method, conventional catalytic method, vapor transfer method, laser heating, differential ionization method,
Independent of electron beam heating or molten crystal pulling methods,
It is to provide a new and improved method of separating materials. However, a further object of the present invention is to provide a new and improved means of electromagnetic separation by selective ionization and magnetic field acceleration. In particular, it is an object to provide a method and a device with low cost and low power for operation with respect to current separation devices.

Another object of the invention is to provide means for forming large area silicon films used in solar cells, especially large area silicon solar cells, in an economically implemented and low power consuming manner. is there.

Yet another object of the invention is that the cost of producing a solar cell, in particular the cost of power consumption of production, is significantly lower than the value of the power expected to be produced by the solar cell during the life of the solar cell. , Refining silicon for solar cells used in terrestrial applications.

Accordingly, the present invention, in one aspect thereof, relates to an apparatus for electrodepositing materials in layers to form semiconductor devices. The plasma spray is magnetically accelerated in the vacuum chamber by a magnetohydrodynamic generator consisting of a cathode, an anode, an accelerating magnet adjacent to the anode and a focusing magnet. The focusing magnet has a pattern of bundles. When the plasma spray is emitted from the plasma generator, the pattern of this bundle can be rotated to orient the plasma spray in different directions. In one aspect of the invention, means are provided for injecting material into the plasma to generate a plasma flow. These implanted materials can include carriers used to separate unwanted impurities from the silicon in the plasma spray. The implanted material can also include a dopant for depositing a doped layer of semiconductor. The doped layer can be of any desired thickness.

In another aspect, a focusing magnet can be placed on the gimbal to rotate the magnetic flux field of the focusing magnet, which allows the material to be evenly deposited on different parts of the target area.

Further, in another aspect of the invention, the device is used to deposit the substrate, followed by the deposition of the semiconductor material.

In yet another aspect, the invention relates to a method of manufacturing a semiconductor material, such as semiconductor grade silicon, in a vacuum environment. A plasma is generated between the cathode and the anode. The Plasya accelerating magnet is accelerated and focused with a focusing magnet onto the deposition zone located above the target zone. A semiconductor material, such as silicon, is placed in the plasma, thereby forming a plasma stream, and a carrier material is injected into the plasma stream to purify the semiconductor material while it is in the plasma.

The deposition zone can be moved along the target zone by changing the orientation of the bundle of focusing magnets.

In yet another aspect, it is possible to form the semiconductor film by robotically removing the finished semiconductor film from the target area and subsequently without having to pump the vacuum chamber each time a new film is formed. it can.

In yet another aspect, the present invention provides a method for purifying a material such as semiconductor grade silicon, particularly providing a vacuum environment and accelerating a plasma with an accelerating magnet and focusing with a focusing magnet onto a target area. Related to the purification of silicon. The material to be purified is placed in the plasma, which forms a plasma stream. The carrier substance combines with impurities in the material to be purified. Thus, the material is deposited on the target area and at the same time the impurities present in the material are removed by means of the vacuum pumping means, together with the carrier substance, mainly as a compound with the carrier substance. By adding a suitable material, for example a dopant, the purified material can be transformed in a plasma stream as the material is deposited on the target area.

The present invention also provides means for preferentially separating isotopes. Most of the compounds are separated for purification.

Referring to FIG. 1, a magnetohydrodynamic deposition apparatus 1 according to the present invention is contained within a vacuum housing 11. Within the upper part 13 of the magnetohydrodynamic depositing device 1 there is an arc-forming compartment 15 surrounded by an accelerating magnet 17, and the lower part of the magnetohydrodynamic depositing device 1 forms a deposition chamber 19. The central part 21 of the device 1 is surrounded by a focusing magnet 23. Deposition chamber
19 is located just below the arc. The plasma in the arc forming section 15 can be accelerated downward by the accelerating magnet 17. The focusing magnet 23 has a tendency to maintain the plasma in a narrow column generally indicated at 25 until the plasma reaches the deposition chamber 19.

A vacuum is maintained in the vacuum housing 11 so that a portion of the ions in the column 25 can be projected into the deposition chamber 19 so that the ions in the plasma column 25 are in contact with the arc forming section 15 and the deposition chamber.
It is necessary to avoid interference with other fluids between 19 and. In a preferred embodiment, a very high vacuum is maintained to a pressure below ^10-4 Torr. It is preferable to maintain a vacuum of 10 ^-10 , but this has proved to be uneconomical, especially when using substantial amounts of carrier material. To achieve these high vacuums, using conventional constant temperature pumps and ion pumps,
Use a combination of low temperature pump and ion pump.

Additional extraction of carrier material is accomplished by the liquid nitrogen-cooling coil assembly 31. A coil assembly 31 is located in the central portion 21 and surrounds the plasma column 25. The gas escaping from the plasma in the column 25 then condenses on the coil assembly 31.

As shown in FIG. 2, the arc forming section 15 comprises a rod-like cathode 41 and a cylindrical anode 43. An injector 45 is mounted adjacent to the cathode so that infused fluid can pass over the cathode. When the arc is established between the cathode 41 and the anode 43, the fluid near the arc is ionized, thus forming an ionized plasma.

Referring again to FIG. 1, the ionized fluid in the arc forming section 15 is accelerated by an accelerating magnet 17 and then focused by a focusing magnet 23 to create a fine column 25 of plasma.
To form. However, if the fluid injected by the injector 45 consists of or forms elements and compounds of different ionization potentials, the element or compound with the highest ionization potential will be affected by the magnetic force when ionized. And therefore will tend to displace elements or compounds with a lower ionization potential in the column 25 of the plasma. Furthermore, when binary compounds are formed rather than ionic compounds, these compounds tend to separate themselves very rapidly from the plasma stream. Thus, such binary compounds can be rapidly extracted. In other words, the ions formed by injecting the fluid with the injector 45 are the accelerating magnet 17 and the focusing magnet.
It is under the influence of the electromagnetic field formed by 23 and follows a controlled orbit. Atoms not under the influence of the electromagnetic field freely diffuse out of the plasma stream. Different trajectories provide a means of separating material seeds.

Due to the reusable different ionization potentials of different materials, the materials can also be separated by ionizing all of the materials. The resulting ions will have different masses and ionization potentials and will therefore have different trajectories when affected by the electromagnetic fields of the accelerating magnet 17 and the focusing magnet 23.

In a preferred embodiment, silicon tetrachloride will be the primary material injected through injector 45, as described below. Elemental silicon becomes separated from the compounds in the arc forming compartment, leaving chlorine and chloride containing impurities. Here the device must incorporate a technique for separating chlorine from silicon while still ensuring that the partial pressure (of chlorine) in the vacuum housing 11 remains at an appropriately low value (10 ^-4 ). Since silicon and chlorine have different ionization potentials, the arc will preferentially ionize silicon. The silicon ions will be trapped by the applied magnetic field, and chlorine will diffuse out of the fine column of ions 25. Coil assembly
31 constitutes the main element in the cryogenic pumping tower.
There is a baffle 51 between the ion column 25 and the coil assembly 31. This baffle 51 serves to protect the coil assembly 31 and prevent the coil assembly 31 from disturbing the narrow beam of plasma.

As the thin beam 25 of plasma enters the deposition chamber, the ions leave a thin beam of ions on the target 53, thus forming a layer or semiconductor device. Ultimately it is desired that the semiconductor material be used outside the device 1, so that the semiconductor device, eg silicon, must be removable from the target area. There are several ways to achieve this: 1. A semi-permanent or temporary layer to which the silicon does not adhere can be placed over the target area. One example of this type of material is boron nitride. Depending on the interface temperature, the boron nitride will decompose to some extent and the boron will diffuse into the film of silicon deposited on the boron nitride. This results in a high degree of doping, making the bottom surface of the silicon conductive (approximately = 10 ^-3 ohm / cm). This allows the bottom surface to act as a back conductor for a semiconductor device that would be formed from a semiconductor material.

2. Silicon can be deposited on a reusable support sheet of refractory material, such as molybdenum or tungsten. By properly controlling the thermal cycle of the support, the silicon deposited on it can be broken and released from the refractory sheet due to the difference in thermal expansion of the two materials.

3. Silicon can be deposited on the surface of a dense "lake", ie, a low vapor pressure liquid metal such as tin.

When depositing silicon on a solid material (as in cases 1 and 2), it is desirable to groove the target material to promote oriented growth of the metal crystals that deposit on the target material. is there. These grooves may have a depth of 5-19 microns, a width of 5-10 microns, and a center-to-center separation between adjacent grooves of 10-15 microns. This promotes alignment of the nucleation centers of the crystals that form during the precipitation of silicon, which causes larger crystals or even single crystal films to be produced.

Dopant Implantation Dopant material can be injected into the plasma stream to form a doped layer on the semiconductor material while controlling the depth and density of the doped layer. This is done by implanting the dopant at the same time as the primary semiconductor material, either from the same implant or separately. Thus, as the semiconductor ions are deposited, the dopants that are placed in the fine columns 25 of the plasma diffuse into the silicon as it deposits on the target 53.

Also, as described above, when depositing silicon on boron nitride, boron doping of silicon occurs especially near the interface between silicon and boron nitride.
The temperature of the support and the film will determine the concentration of boron and the penetration of boron into the silicon.

The table below describes the physical properties of various materials injected by this system. Ideally, the injected material is in liquid form. The ionization potential of the element to be precipitated should be relatively high and the ionization potential of the carrier material should be relatively low. The melting and boiling points of the material are important for the purpose of extracting the material by passing cold material through the assembly 31 of the coil.

Method automation considerations One vacuum pump-down op
In order to produce multi-square-meter semiconductor grade silicon films by eration) some method must be devised to move the support and / or target material. In the embodiment where a solid support is used in the target area, the film of the Taiyo battery deposited on the target 53 is removed from the target 53 and stored in the vacuum housing 11 so that the subsequent film can be transferred to the target 53.
To be deposited on top.

Target Subsequent Films Using Robot 55 53
Lift from. Then a plurality of finished films 57
Is stored by the robot 55 in the deposition chamber 19 away from the target 53 and the plasma column 25.
It will be appreciated that the storage of the finished film 57 allows the device 1 to continuously deposit subsequent films.

It is also possible to place a support (not shown) preformed on the target 53 on the target 53 before the deposition of each film by the device. Thus, each of the finished films 57 has a support for itself, and each support can be lifted with the film or later separated from the film.

In the case where silicon is deposited on the surface of the liquid metal, the robot 55 can be used to pull the film along the surface of the liquid. The film is continuously deposited and the film is cut to the desired length using cutting means, such as a laser (not shown), and the cut is then stored as a finished film 57.

FIG. 4 shows the relative positional relationship among the cathode 41, the anode 43, the acceleration magnet 17, the focusing magnet 23, and the target 53.

Operation Referring to FIG. 3, the method for purifying silicon is carried out by carefully controlling the different materials injected into the system and the parameters of arc control and plasma focusing. Pressure from the pressure controller 61 is applied to the silicon tetrachloride source 63. Silicon tetrachloride is injected into the arc forming section 15 by an evaporator and flow controller 65. Hydrogen source 77
Hydrogen from can be injected to provide additional carrier gas to remove impurities and to promote plasma spray formation. The various gases formed in the arc forming section 15 are withdrawn in the vacuum pump section 79. The ions ejected from arc-powered compartment 15 are preferentially ionized to direct silicon and other materials to be deposited on target 53 (FIG. 1) in the process represented by block 81. This is achieved by the outgassing provided by the vacuum pump compartment 79 as well as the focusing magnet 23. The focusing magnet directs the ions to a target 53 in the deposition chamber 19, as represented by step 83. In step 85, the support is prepared to receive the column of ions 25. This step heat-processes the support to bond it to the deposited material, or gradually separate from it, as appropriate, at a suitable temperature. This is represented by block 87 as part of the fabrication of the support. Upon impacting the target, the ions form a crystalline film, represented by step 89. Hydrogen supplied at 77 can be used to form a plasma, heat process the silicon, and prepare the silicon to receive the silicon layer. This is represented by block 91.

The final processing is performed at block 97. This treatment can include depositing a thin layer of arsenic to improve the photosensitivity of the resulting photovoltaic cell. Finally in step 99,
After the final silicon film is formed, the completed film 57 is taken out of the deposition chamber 19.

Magnet Integration Target 53 if large area film support is desired
Needs to be integrated with respect to the thin column 25 of plasma. This articulation provides a larger spray pattern on the target 53 than simply allowing the column of plasma 25 to diffuse.

As previously mentioned, when focusing the thin plasma column 25 onto a liquid metal support, a robot 55 is used to pull the deposited material along the "rake" of the liquid metal, thus creating a thin plasma column 25. The target 53 can be effectively taken out with respect to.

However, when using a solid support it is necessary to move the target 53 or the plasma column 25. When trying to hold the target 53 in a specified position, the thin plasma column 25 can be integrated by shifting the magnetic field of the focusing magnet 23. This can be achieved by providing an integral part 101 of the focusing magnet 23. The integrated portion 101 functions as part of the focusing magnet 23, but shifts the axis of the magnet or shifts the pattern of its bundle so that the plasma can reach the target 53.
A thin beam 25 of plasma can be angularly deflected as it arrives at. This can be done by selectively utilizing a portion of the integrated portion 101 or by physically rotating the integrated portion 101 on the gimbal device.

While the invention is believed to be what is believed to be the preferred embodiment, it is contemplated that further modifications may be made to increase the operational efficiency of magnetohydrodynamic refining techniques. For example,
It is possible to place a movable support or a disposable support between the films in a sandwich-like manner to deposit multiple silicon films on the target 53. Other elemental semiconductors, such as germanium, can be used in place of silicon. Thus, although the present invention has been described in accordance with the preferred embodiment, it is not limited thereby.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a magnetohydrodynamic device according to the present invention. FIG. 2 is a schematic diagram of the arc forming area of the preferred embodiment of the present invention. FIG. 3 is a block diagram showing a method for forming a semiconductor film according to the present invention. FIG. 4 is a schematic diagram showing the relative positional relationship of the cathode, anode, accelerating magnet, focusing magnet and target. 1 ... Magnetohydrodynamic deposition equipment 11 ... Vacuum housing 13 ... Top 15 ... Arc-forming compartment, Hall current accelerator, cold silicon or hot tungsten anode 17 ... Accelerating magnet 19 ... Deposition chamber 21 ... Central part 23 …… Focusing magnet 25 …… Thin column 31 …… Liquid nitrogen-cooling coil assembly 41 …… Rod-like cathode 43 …… Cylindrical anode 45 …… Injector 51 …… Baffle 53 …… Target 55 …… Robot 57 …… Completed film 61 …… Pressure control device 63 …… Silicon tetrachloride source 65 …… Evaporator + sonic orifice or mass flow detection means device 77 …… Hydrogen source, H ₂ tank 79 …… Vacuum pump compartment , cryogenic pump, adjusting background ^<10-4 81 ...... differential ionization + trapping of silicon lot 83 ...... beam diameter + through the cryogenic pump enters the deposition chamber channel ions in the support 85 ... Polycrystalline 10 large heat treatment 89 ...... silicon film processing 87 ...... support of the support by precipitating
Forming 30μ 91 …… Heat treatment of silicon film with H ₂ 97 …… Deposition of coating 99 …… Removal of completed film 101 …… Integrated part of focusing magnet

Claims (48)

[Claims] 1. A device for purifying semiconductor materials by using a magnetically accelerated plasma spray in a vacuum, comprising: a) a vacuum chamber and associated vacuum pumping device; b) a magnetohydrodynamic Hall effect. A plasma generator, where the plasma generator is a cathode having an axis, an anode having an axis, the cathode and the anode are spaced from each other and are arranged with a common axis, and the anode is adjacent to the cathode. An accelerating magnet having a side surface and a side surface opposite the cathode, the accelerating magnet having an axis coaxial with the cathode and the anode, the accelerating magnet being spaced from them around at least a portion of the cathode and around at least a portion of the anode. And a focusing magnet having an axis coaxial with the anode, cathode and accelerating magnet, at least a portion of the focusing magnet extending axially on the side of the anode opposite the cathode. , C) a support structure for the plasma generator, wherein the support structure supports the plasma generator in a vacuum chamber; d) a means for supplying power to the plasma generator, here the power Is predominantly direct current, and electric power causes the plasma generator to generate a plasma; e) a target surface, where the target surface is on the side of the focusing magnet opposite the cathode and anode. Located on the axis of; f) means for injecting material into the plasma to generate a plasma flow; g) a breakthrough that allows access to the vacuum chamber from the outside, where this breakout has sealing means. The injected material is preferentially ionized by the plasma generator, thereby separating impurities in the material while present in the plasma stream; A device comprising: 2. The means for injecting a material into a plasma can receive a carrier material, said carrier material combining with impurities present in the semiconductor material in the plasma stream to deposit the semiconductor material in the target area. An apparatus according to claim 1, which was previously effective for separating impurities from the semiconductor material, so that the semiconductor material can be deposited in a state of purity greater than that of the semiconductor material before deposition. 3. The means for injecting material into a plasma can further inject a dopant material, whereby the dopant material is applied to the semiconductor material when the semiconductor material is applied to the target area. A device according to claim 2 4. The device of claim 3 wherein the dopant is mixed with the carrier material. 5. The apparatus of claim 2 further including robotic means, the robotic means operable to move material to and from the target area. 6. A device according to claim 5, wherein the cathode is a thermionic cathode. 7. The apparatus of claim 2 wherein elemental silicon is injected as a liquid into the plasma generator during operation of the apparatus. 8. A device according to claim 2 or 3, wherein the means for injecting the material injects the material adjacent the cathode. 9. A device according to claim 1 or 3, wherein the cathode is a thermionic cathode. 10. An apparatus according to claim 1 or 2, wherein silicon is injected into the plasma generator during operation of the apparatus. 11. A device according to claim 10, wherein silicon is injected as a liquid compound. 12. A device according to claim 10, wherein silicon is implanted in the anode. 13. A device according to claim 10, wherein silicon is implanted in the cathode. 14. The apparatus according to claim 1 or 2, wherein the vacuum pump device comprises a low temperature vacuum pump device and an ion vacuum pump device. 15. The apparatus of claim 1 wherein the implanted material comprises silicon, and preferential ionization and separation of impurities from the semiconductor material produce semiconductor grade silicon deposited on the target surface. . 16. Apparatus according to claim 1 or claim 15 in which a coil assembly is provided for condensing the material escaping from the plasma stream. 17. The plasma generator is surrounded by an accelerating magnet, which accelerates the plasma, whereby the material in the plasma is transferred away from the plasma generator. The apparatus according to paragraph 15. 18. A device for purifying semiconductor metals used in the formation of semiconductor bonding devices by magnetically accelerated plasma spraying in vacuum, comprising: a) a vacuum chamber and associated vacuum pumping device; b) a magnetic fluid. A mechanical Hall effect plasma generator, wherein the plasma generator comprises a thermionic cathode, an anode, an accelerating magnet located adjacent to the cathode, a focusing magnet, and at least a portion of the focusing magnet Located on the opposite side of the anode from the cathode; c) a support structure for a plasma generator, wherein the support structure supports the plasma generator in a vacuum chamber; d) Means for supplying power to the plasma generator, wherein the power is primarily direct current, and the power is a plasma having ions from the thermionic cathode in the plasma generator. A stream can be generated; e) means for supplying a semiconductor material to the plasma generator, wherein the semiconductor material has a purity lower than that required for the semiconductor; f) a target area, here the target area. Is located in a vacuum chamber, whereby the plasma stream is discharged by the plasma generator, and then the material in the plasma stream can be deposited in the target area; g) means for injecting carrier material into the plasma stream; h) a vacuum chamber opening, wherein the opening is accessible from the outside of the vacuum chamber into the vacuum chamber and has a sealing means, wherein the carrier material comprises the carrier material and the semiconductor material in a plasma flow. When present, they combine with impurities in the semiconductor material and the material is preferentially ionized, which causes the impurities to pre-exist Apparatus characterized by consisting of: is separated from the semiconductor material while the material is present in the plasma flow. 19. The apparatus of claim 18 further including robotic means, wherein the robotic means is operable to move and remove material from the target area. 20. The device of claim 18 wherein the semiconductor material is silicon and the silicon is implanted in the anode. 21. The semiconductor material according to claim 18, wherein the semiconductor material is silicon, and the silicon is implanted adjacent to the cathode.
The device according to the item. 22. The device according to claim 18, wherein the vacuum pump device comprises a low temperature vacuum pump device and an ion vacuum pump device. 23. The semiconductor material fed to the plasma generator is metallurgical grade silicon, and preferential ionization and separation of impurities from the semiconductor material produce semiconductor grade silicon deposited in the target area. The device according to claim 18. 24. Apparatus according to claim 18 or 23 wherein the coil assembly is provided to condense material escaping the plasma stream. 25. The plasma generator is surrounded by an accelerating magnet, which accelerates the plasma, whereby the material in the plasma is transferred away from the plasma generator. The apparatus according to paragraph 23. 26. A device for purifying semiconductor metal used in the formation of semiconductor bonding devices by plasma spraying magnetically accelerated in a vacuum, comprising: a) a vacuum chamber and associated vacuum pumping device; b) a magnetic fluid. A mechanical plasma generator, where the plasma generator is a cathode with an axis, an anode with an axis, the cathode and the anode are spaced from one another and are arranged with a common axis, the anode being the cathode An accelerating magnet having an axis co-axial with the cathode and the anode, the accelerating magnet having at least a portion of the cathode and at least a portion of the anode, the accelerating magnet having an adjacent side surface and a side surface opposite the cathode; A focusing magnet, spaced apart from and having an axis coaxial with the anode, cathode and accelerating magnet, at least a portion of the focusing magnet extending axially on the side of the anode opposite the cathode. hand C) a support structure for a plasma generator, wherein the support structure supports the plasma generator in a vacuum chamber; d) means for supplying power to the plasma generator, And this power is predominantly direct current, and the power makes it possible to generate a plasma in the plasma generator; e) a target surface, where the target surface is focused on the side of the focusing magnet opposite to the cathode and the anode. Located on the axis of the magnet; f) means for feeding the material into the plasma to generate a plasma flow; g) a tampering port that allows access to the interior of the tampering chamber from outside.
Where the tamper has sealing means; h) a coil assembly, wherein the coil assembly is located substantially concentrically within the focusing magnet and cools the gas escaping from the plasma, and thereby the gas. I) a baffle assembly, wherein the baffle assembly is located substantially concentrically within the coil assembly and surrounds the plasma to protect the coil assembly from the plasma. And separating from the plasma. 27. An apparatus for purifying semiconductor metal used in the formation of semiconductor bonding devices by magnetically accelerated plasma spraying in vacuum, comprising: a) a vacuum chamber and associated vacuum pumping device; b) a magnetic fluid. A mechanical plasma generator, where the plasma generator is an ion cathode with an axis, an anode with an axis, the cathode and the anode are spaced from one another and are arranged with a common axis, the anode being the cathode An accelerating magnet having an axis coaxial with the cathode and the anode, the accelerating magnet having a side surface adjacent to the cathode and a side surface opposite to the cathode, the accelerating magnet around at least a portion of the cathode, and at least a portion of the anode. A focusing magnet spaced from them and having an axis coaxial with the anode, the cathode and the accelerating magnet, at least part of the focusing magnet being axially on the side of the anode opposite to the cathode C) a support structure for the plasma generator, wherein the support structure supports the plasma generator in a vacuum chamber; d) means for supplying power to the plasma generator , Where this power is predominantly direct current, and the power makes it possible to generate a plasma with ions from the thermionic cathode in the plasma generator; e) a target area, where the target area is a vacuum. Located inside the chamber, whereby the plasma stream is discharged by the plasma generator, then the material in the plasma stream can be deposited in the target zone; f) means for injecting material into the plasma stream; g) vacuum A chamber opening, where the opening is accessible to the vacuum chamber from outside the vacuum chamber and has sealing means; h) Coil assembly Lee, where the coil assembly is located substantially concentrically within the focusing magnet and cools gas escaping from the plasma, thereby condensing the gas; and i) a baffle assembly, where A baffle assembly located substantially concentrically within the coil assembly and surrounding the plasma to protect the coil assembly from and separate from the plasma. . 28. An apparatus for purifying a metal by magnetically accelerated plasma spraying in a vacuum, comprising: a) a vacuum chamber; b) a magnetohydrodynamic plasma generator, wherein the plasma generator comprises: ) A cathode having an axis, 2) An anode having an axis, the cathode and the anode are arranged at a distance from each other and have a common axis, and the anode is a side surface adjacent to the cathode and a side surface opposite to the cathode. 3) an accelerating means having an axis coaxial with the cathode and the anode, the accelerating means being spaced around them at least around a portion of the cathode and around at least a portion of the anode And 4) focusing means having an axis coaxial with the anode, the cathode and the accelerating means, at least part of the focusing means extending axially on the side of the anode opposite to the cathode, 5) the plasma generation The vacuum chamber C) means for supplying power to the plasma generator and thereby generating a plasma flow in the plasma generator; d) located in the vacuum chamber A target area for receiving material contained in said plasma stream; e) means for injecting material into said plasma stream; and f) a coil assembly, wherein said coil assembly is located surrounded by said plasma stream and Cooling the gas escaping from the plasma, thereby condensing the gas. 29. An apparatus according to claim 28, wherein said cathode comprises a thermionic cathode. 30. The apparatus according to claim 28, wherein said plasma accelerating means comprises a magnet. 31. The apparatus according to claim 28 or 30, wherein the plasma converging means is a magnet. 32. The apparatus of claim 28, wherein the power is primarily direct current. 33. Apparatus according to claim 28 or 32 further comprising a tampering opening for the vacuum chamber, the tampering opening being accessible from outside the vacuum chamber to the vacuum chamber and including sealing means. 34. A baffle assembly further comprising: a baffle assembly located substantially concentrically within said coil assembly and surrounding said plasma stream to direct said coil assembly into said plasma stream. 29. Apparatus according to claim 28, which is protected from the plasma and separated from the plasma stream. 35. Apparatus according to claim 28 or 34 wherein said coil assembly is located substantially concentrically within said converging means. 36. An apparatus according to claim 35, wherein said focusing means comprises a magnet. 37. The apparatus according to claim 36, wherein said accelerating means comprises a magnet. 38. A method of purifying a semiconductor material, comprising: a) providing a vacuum environment; b) establishing a plasma between an anode and a cathode; c) accelerating the plasma with an accelerating magnet; d) A material containing a semiconductor metal is placed in a plasma, thereby forming a plasma stream, e) focusing the plasma stream with a focusing magnet onto a deposition zone; f) injecting a carrier material into the plasma stream, where The carrier material chemically bonds with impurities present in the semiconductor material in the plasma stream, whereby the semiconductor metal is dissociated from the impurities in the plasma stream prior to said depositing. 39. The method according to claim 38, wherein the semiconductor material is injected into the plasma. 40. The method of claim 39, wherein the semiconductor material is implanted as an element in liquid form. 41. The method according to claim 38, wherein the semiconductor material is arranged in the plasma in the form of a thermionic cathode. 42. The method according to claim 38, wherein the semiconductor material is silicon. 43. A method for purifying silicon, comprising: a) providing a vacuum environment; b) establishing a plasma between a cathode and an anode; c) accelerating the plasma with an accelerating magnet; d) plasma. Is focused with a focusing magnet onto a deposition zone located in the target zone; e) placing the semiconductor material in a plasma, thereby forming a plasma stream; f) injecting a carrier material into the plasma stream, where The carrier material chemically bonds with impurities present in the semiconductor material in the plasma stream; and g) withdrawing the carrier material and impurities from the vacuum chamber with a vacuum pump. 44. The method of claim 43, wherein the semiconductor material is placed in a plasma by forming the cathode as a thermionic cathode made from the semiconductor material. 45. The method according to claim 43, wherein the semiconductor material is placed in the plasma by means of implantation. 46. The method according to claim 43 or 45, wherein the vacuum pump comprises a combination of a cryopump and an ion pump. 47. The method of claim 45, wherein the semiconductor material is silicon. 48. The method of claim 47, further comprising the step of selectively implanting a dopant into the plasma stream so that the purified silicon has a doped layer.