JPS6148416A - Electromagnetic fluid dynamic device and process for separating and depositing material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Separation of materials can be achieved by applying or influencing force on individual species of the material or on compound species of the material. These forces are gravitational force, electromagnetic force, gas (fluid) power, and/or a combination of these forces. These forces impart different accelerations to the species, thereby imparting different spatial and temporal properties to the desired separation.

The material may be in a solid, liquid, vapor or plasma state, or a combination thereof.
mic process) encompasses each or a combination of these states.

'&f: The magnetohydrodynamic phenomenon was first discovered by Can in 1961 and published in U.S. Pat.
, No. 243.954. The device designed and tested is intended for space propulsion applications and is commonly known as an ion propulsion system. The main design and performance requirements were to completely ionize a single species of vapor and accelerate all ions into space at a desirable high velocity. This device must have high thrust efficiency, and here the thruster
stor) efficiency was defined as: Thrust efficiency =
η mass φη discharge% ”η here ηit soil utilization efficiency average velocity of injected mass ions maximum velocity of ions η power = power efficiency hand 1 power = m x (21 )”
ions where: m io = mass flow of ions = average velocity of ions No attempt has been made to separate materials in this way. This is because the intended application was not directed towards 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). The phenomenon of this type of interaction is hereinafter referred to as the Hall current effect (H
all current effect).
The significance of the research by Cann et al. is that the cavity (ca
controllable injection of feed or propellant into the anode section of the vity. Appropriate selection of voltage and propellant injection rate results in ionization and acceleration of charged particles (ions and electrons) in a direction parallel to the applied magnetic field. The resulting plasma has a desired exhaust rate (exha
ust velocft 'y).

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

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

An important use of the method and apparatus of the present invention is to produce semiconductor grade silicon from low cost silicon compounds as feedstock. 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 should be practically at least 99.999% pure, preferably at least 99.9999% pure.

On the other hand, silicon with a purity of at least 97% is considered metallurgical grade silicon. Commercially available metallurgical grade silicon e is approximately 98
% purity. Semiconductor grade silicon costs significantly more than metallurgical grade silicon; in 1980, semiconductor grade silicon cost approximately $80/kg, whereas metallurgical grade silicon cost $1/kg. The cost is less than $/kg.

Ironically, semiconductor grades are valuable because they are commonly used in products that require the addition of specific impurities or "dopants" to silicon. These dopants affect the conductivity of the silicon and create part of the donor and part of the septum in the semiconductor device. Therefore, “semiconductor grade silicon (semfconductor gracle 5
ificon) J as used herein should be interpreted to include highly pure silicon doped with dopants.

As mentioned above, semiconductor grade silicon is used in the manufacture of many semiconductor devices, such as silicon solar cells.

It is important to reduce the cost of manufacturing solar cells so that the manufacturing of the solar cells is compensated for by the expected lifetime of the solar cells. Currently, silicon solar cells are made from single crystals of n-type silicon that are about 4 centimeters in diameter and about the length of a sausage. These crystals are created by spinning and pulling at a slow regulated pace.
The elongated crystals are then cut into approximately 50 micron thick slices with a diamond two-beam circular saw.

The slices are polished, lapped, and chemically cleaned;
The crystal is then heated to 1150° C. in an atmosphere of boron chloride, placed in a diffusion chamber consisting of a long quartz tube running through a cylindrical electric furnace. Elemental boron decomposing from the boron compound diffuses into the outer surface of the silicon wafer, thus doping the wafer to 0.3
Create a p-type layer thinner than a micron. Further processing is required to create the terminals and expose the n-type silicon sandwiched here in the center.

Although this method is ideal for manufacturing small electrical components, the steps involved make solar panels cost 12.5 million yen per kilowatt of power generated. It is assumed to be more than OOO dollars, that is, (1973 dollars).

Although the ideal cost of manufacturing is expected to decrease as manufacturing technology and mass production improve, prices will be lower than solar cells used commercially for the generation of power in non-remote areas such as spacecraft. It is still several orders of magnitude too large for the panel. Also, in many cases the energy consumed in production cannot be recovered from the expected lifetime of the solar cell.

Several systems have been proposed for manufacturing semiconductor devices, e.g. solar cells, by other means.6 See, for example, U.S. Pat.
al,) (Also, United 5tates
Patent Office Voluntary
Protest Program Docum
ent No. B 65105) discloses a method for the production of solar cells, consisting of injecting p- or n-doped silicon particles into a plasma stream, in which the particles are evaporated.9 Then the heated particles is polished from the plasma stream onto the substrate to form a polycrystalline silicon film. 1111 of heating and spraying, providing a suitable atmosphere surrounding the particles to prevent oxidation; however, U.S. Pat. No. 4,003,770 does not suggest using this technique for the purification of silicon; U.S. Patent No. 2.53
No. 7.255 (Walter H, Brattain
) discloses the deposition of silicon for silicone emf cells using a mixture of hydrogen and silicon tetrachloride. However, this early technology does not disclose the use of magnetohydrodynamic effects for either the production of these solar cells or the purification of metallurgical grade silicon to semiconductor grade silicon.

U.S. Patent No. FF13,916,034 (Tsuchim
oto) discloses a method for transferring a semiconductor in a plasma stream onto a substrate. The plasma is directed onto the thin film substrate by a magnetic field. U.S. Patent No. 3,916,03
No. 4 is a conventional magnetohydrodynamic (magnet oga
This is a representative of the sdynamic c) method. In the magnetohydrodynamic method, mass utilization efficiency (mass u
tilization efficiency) is low, making this method ineffective for purifying large quantities of silicon.

It is also possible to create a deposition system using a magnetohydrodynamic arc, where the magnetic nozzle is created by a co-coil and/or by the self-magnetic 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 the electromagnetic (jXB) force to uniformly erode the anode.

However, this system is limited to "modes of (m.

dal) J performance, where small changes in mass flow rate critically affect the voltage requirements of this system,
In this system, the IJA electrode and cathode ltH insulators can erode or become coated during operation of the plasma device, thereby shorting the radiation path.

It is therefore an object of the present invention to provide a method and apparatus for refining silicon, in particular for refining metallurgical grade silicon into a purer form of silicon to produce semiconductor grade silicon. .

Another object of the invention is to produce semiconductor grade materials in the form of large area thin films, thereby providing an inexpensive base product for 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 use conventional chemical reduction methods, conventional catalytic methods, vapor transfer methods, laser heating, differential ionization methods for the separation of Katsura.
To provide a new and improved method of separating materials that does not rely on electron beam heating or fused crystal pulling methods. However, a further object of the invention is to provide a new and improved means of electromagnetic separation by selective ionization and acceleration of magnetic fields. In particular, it is an aim to provide a method and a device that is low in cost and requires low power for operation with respect to current separation devices.

Another object of the present invention is to provide a means for forming large area silicon films for use in solar cells, particularly large area silicon solar cells, in an economically viable and low power consumption manner. be.

Still another object of the present invention is to reduce the production cost of solar cells, especially the cost of power consumption during production, by a factor of IIJ over the lifetime of the solar cell.
I, to refine silicon for solar cells used in terrestrial applications, which is significantly lower than the power values expected to be produced by solar cells.

Accordingly, one aspect of the present invention relates to an apparatus for depositing material in layers by electrodeposition to form a semiconductor device 2t. A magnetohydrodynamic generator consisting of a cathode, an anode, an accelerating magnet adjacent to the anode, and a focusing magnet magnetically accelerates the plasma spray within the vacuum chamber. A focusing magnet has a pattern of flux. When the plasma spray is emitted from the plasma generator, this bundle pattern can be rotated to direct 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 stream. These implanted materials can include carriers used to separate unwanted impurities from the silicon in the plasma spray. The implanted material may also include a dopant for depositing a doped layer of the semiconductor. The doped layer can be of any desired thickness.

In another aspect, a focusing magnet can be placed on a gimbal to rotate the magnetic flux field of the focusing magnet, thereby uniformly depositing material onto different portions of the target area.

In yet another aspect of the invention, the apparatus is used to deposit the substrate and then deposit the semiconductor material.

In yet another aspect, the invention relates to a method of manufacturing semiconductor materials, such as semiconductor grade silicon, in a vacuum environment. Plasma is generated between a cathode and an anode. The plasma is accelerated by an accelerating magnet and focused by a focusing magnet onto a deposition area located above the target area. Semiconductor material 1, for example silicon, is placed in a plasma, thereby forming a plasma wave, and a carrier material is injected into the plasma stream to purify the conductor material in which the semiconductor material is present in the plasma.

The deposition area can be moved along the target area by changing the orientation of the focusing magnet flux.

In yet another aspect, it is possible to remove the completed semiconductor film from the target area by robotic means to subsequently form a semiconductor film without the need for bombing a vacuum chamber each time a new film is formed. can.

In yet another aspect, the present invention provides a method for refining materials such as semiconductor grade silicon, in particular providing a vacuum environment and accelerating a plasma with an accelerating magnet and focusing it onto a target area with a focusing magnet. Concerning the purification of silicon consisting of. The material to be purified is placed in the plasma, thereby forming a plasma stream. The carrier substance binds impurities in the material to be purified. The material is thus deposited onto the target area and at the same time the impurities present in the material are removed together with the carrier substance, primarily as a compound with the carrier substance, by means of a vacuum pump. Suitable materials, e.g.

The addition of dopants allows the purified material to be transformed in the plasma stream as the material is deposited onto the target area.

The present invention also provides a means to preferentially separate isotopes. In addition, separation of most compounds is carried out for purposes such as purification.

Referring to FIG. 1, a magnetohydrodynamic deposition apparatus 1 according to the present invention is contained within a vacuum housing 11. As shown in FIG. In the upper part 13 of the magnetohydrodynamic deposition device 1 there is an arc-forming section 15 surrounded by accelerating magnets 17, and the lower part of the magnetohydrodynamic deposition device l forms a deposition chamber 19. The central part 21 of the device 1 is surrounded by a focusing magnet 23 . The deposition chamber 19 is located directly below the arc. The plasma in the arc forming section 15 can be accelerated downward by an accelerating magnet 17. Focusing magnet 23 tends to maintain the plasma in a regular column generally indicated at 25 until it reaches deposition chamber 19 .

A vacuum is maintained within the vacuum housing 11 such that a portion of the ions within the column 25 can be projected into the deposition chamber 19 so that the ions within the column 25 of the plasma can be projected into the arc forming section 1.
5 and the precipitation chamber 19, it is necessary to avoid interference by other fluids. In a preferred embodiment, a very high vacuum is maintained such that the pressure is less than 10-'), especially when using a substantial amount of carrier material. It has been shown that this is uneconomical. To achieve these high vacuums, conventional cryo-pumps and ion pumps are used, and a combination of cryo-pumps and ion pumps is used.

Additional extraction of carrier material is accomplished by a liquid nitrogen-cooling coil assembly 31.

positioning the coil assembly 31 in the central portion 21;
The gas surrounding the column 25 of plasma and escaping from the plasma within the column 25 is then transferred to the coil assembly 3.
Condensate on 1.

As shown in FIG.
1 and a cylindrical anode 43. An injector 45 is mounted adjacent to the cathode to allow injected fluid to pass over the cathode.

When an arc is established between cathode 41 and anode 43, the fluid in the vicinity of the arc is ionized, thus forming an ionized plasma.

Referring again to FIG. 1, the ionized fluid in arc forming section 15 is accelerated by accelerating magnet 17 and focused by focusing magnet 23 to form a narrow column 25 of plasma. However, if the fluid injected by the injector 45 is composed of or forms elements and compounds of different ionization potentials, the element or compound with the highest ionization potential will be more influenced by the magnetic force when ionized. ions and will therefore tend to replace elements or compounds with lower ionization potentials in the column 25 of the plasma.

If binary compounds rather than ionic compounds are formed, these compounds tend to separate themselves from the plasma stream very rapidly. Thus, such binary compounds can be rapidly extracted. In other words, the ions formed by injecting the fluid with the injector 45 are under the influence of the electromagnetic field formed by the accelerating magnet 17 and the focusing magnet 23 and follow a restricted trajectory. Atoms not under the influence of the electromagnetic field are free to diffuse out of the plasma stream. Different trajectories provide a means to separate species of material.

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

As discussed below, in a preferred embodiment, silicon tetrachloride is injected through the injector 45 so that the primary material, elemental silicon, is separated from the compound in the arc forming zone, thereby removing chlorine and impurity-containing compounds. Chloride remains. Here the device is a vacuum housing
The ionization potentials of silicon and chlorine are different, and techniques must be incorporated to separate chlorine from silicon while still ensuring that the partial pressure (of chlorine) in Because the arc will preferentially ionize silicon, the silicon ions will be trapped by the applied magnetic field and the chlorine will diffuse out of the narrow column of ions 25 because the coil assembly 31 is at a low temperature. It constitutes the main element in the pumping tower. A baffle 51 is present between the ion column 25 and the coil assembly 31. This baffle 51 serves to protect the coil assembly 31 and prevent it from disturbing the narrow beam of plasma.

When the narrow beam 25 of plasma enters the deposition chamber, the ions leave a narrow 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 package 21, so
The semiconductor device, e.g. silicon, must be removable from the target area; there are several ways to achieve this: 1. Place a semi-permanent or temporary layer over the target area to which the silicon does not adhere; be able to. One example of this type of material is boron nitride. Depending on the interfacial temperature, boron nitride decomposes to some extent, and boron precipitates on boron nitride by 1'°''.
There will be 1 in 4 diffused, which will result in a high degree of doping and make the bottom surface of the silicon conductive (to-' ohm/am), so that the bottom surface can be made of semiconductor material. backside conductor (bac) for semiconductor devices
k conductor).

2. Silicon can be deposited on a reusable support sheet of refractory material, such as molybdenum or tungsten. By properly controlling the thermal cycling of the support, the silicon deposited thereon can be broken free 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 onto a solid material (as in cases 1 and 2), it may be desirable to groove the target material to promote oriented growth of the metal crystals deposited on the target material. be. These grooves can be 5 to 19 microns deep, 5 to 10 microns wide, and the center-to-center separation between adjacent grooves can be 10 to 15 microns. This promotes alignment of the nucleation centers of the crystals that form during silicon precipitation, thereby producing large crystals or even single crystal films.

Dopant--The dopant material can then be injected into a plasma stream to form a doped layer on the semiconductor material, controlling the depth and density of the doped layer. This is accomplished by implanting the dopant at the same time as the primary semiconductor material, either through the same injection port or separately. Thus, when semiconductor ions are deposited, the dopants placed in the narrow column 25 of the plasma are silicon-based at the target 53.
As it precipitates upward, it diffuses into the silicon.

Also, as mentioned above, when silicon is deposited onto boron nitride, doping of the silicon with boron occurs particularly near the interface between the silicon and boron nitride.

The temperature of the support and film will determine the concentration of boron and its penetration 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 deposited should be relatively high and the ionization potential of the carrier material should be relatively low. The melting point and point of the material is important for the purpose of extracting the material by passing the cold material through the assembly 31 of coils.

Ionized Po Chloride and/ ■ Materials - Ritou Yu-Nienno Group or Water - JJjSi Silecoy 28.06
8. L2 (melting point = t4zo℃: C1114 element
35.46 12.95 Cl2H Hydrogen 1.00 13.53 H2N
Nitrogen 14.01 14.48 N
Hydrogen dichloride 36-46 N, A,
MCl-1 on plate E-1, Tet5') ao 168.29 N, A,
SiC1msilane2, t+)chlorosi 135.44 N, A,
5iHC13 Run 3, Dichlorosilica 100.99 N, A,
5iH2C12-4, Chlorosilane 66.54 N, A,
5iH1C15, Shira 7 32.09 N,
A-5iH46, Kushi 5in 62.17 N,
A, Siz Ha7, ) IJ S5y
92.24 N, A, 5i3Hs8, Tetrasilane 122.32 N, A, Si*H+.

Melting point Boiling point
．． 6 -34.7 10”-259,14-2
52,8103 -209,86-195,8760 -112-83,71,5XIO-5 -7057,57N,A.

-13433, ON, A.

-1128,3N,A.

-118,1-30,4N,A.

-185-118,8N,A.

132.5 -14. ．． 5 N, A.

-177,452,9N,A.

-93,580N,A.

・Suno f - 1 vacuum pump - down operation (vacuumpump
In order to produce films of multiple square meters of semiconductor grade silicon in -down operations, some method of moving the support and/or target material must be devised, using a solid support in the target area. In embodiments, a film of solar cells deposited on target 53 is removed from target 53 and stored in a vacuum housing 11 so that subsequent films can be deposited on target 53.

The robot 55 is used to lift successive films from the target 53.The completed films 57 are then stored by the robot 55 in the deposition chamber 19 away from the target film 531-3 and the plasma column 25. It will be appreciated that the storage of the finished film 57 allows the device I to deposit successive films in succession.

“Before deposition of each film with 1 tHk, target 5
It is also possible to place a preformed support on target 53 (not shown) on target 53 .

Each of the completed films 57 thus has a support for itself, and each support can be lifted with the film or later separated from the film.

In cases where silicon is deposited onto the surface of a liquid metal, the robot 55 can be used to draw a film along the surface of the liquid. The film is deposited continuously and cut by means of cutting, e.g.

A laser (not shown) is used to cut the film to the desired length, and the cuts are then stored as finished film 57.

- Handling - Referring to Figure 3, the method for refining silicon is carried out by carefully controlling the different materials injected into the system, as well as the arc control and plasma focusing parameters. Pressure from pressure controller 61 is applied to silicon tetrachloride source 63. Silicon tetrachloride is injected into arc forming section 15 by evaporator and flow control device 65 .

Hydrogen from a hydrogen source 77 can be injected to provide additional carrier gas to remove impurities and facilitate formation of the plasma spray. The various gases formed in the arc forming section 15 are extracted in the vacuum pump section 79. Ions emitted from arc forming section 15 are preferentially ionized and direct silicon and other materials to be deposited on target s3 (FIG. x) in the step represented by block 81. This is accomplished by gas evacuation performed by vacuum pump section 79 as well as focusing magnet 23. The focusing magnet is placed in the deposition chamber 19, as represented by step 83.
Aim at target 53 Heion. In step 85, a support is prepared to receive the column 25 of ions. This step thermally processes the support to cause it to adhere to or gradually separate from the deposited material, as desired, at a suitable temperature. This is represented by block 87 as part of the processing of the support. When the ions impact the target, they form a crystalline film, represented by step 89. The hydrogen provided at 77 can be used to form a plasma, thermally process the silicon, and deposit the silicon to receive the silicon layer. This is represented by block 91.

Final processing is performed at block 97. This treatment can include depositing a thin layer of arsenic to improve the photosensitivity properties of the resulting photovoltaic cell. Finally, in step 99, the completed film 57 is removed from the deposition chamber 19 after the last silicon film has been formed.

21 pieces of single-magnetic support - If a large area film support is desired, target 5
3 with respect to a thin column 25 of plasma. This articulation provides a larger spray pattern on the target 53 that allows the column 25 of plasma to spread out.

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

However, when using a solid support, it is necessary to move the target 53 or the column of plasma 25. If the target 53 is to be held in a specific position, the narrow column 25 of plasma 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 part 101 is the converging magnet 2
3, but can shift the axis of its magnet or shift its flux pattern to angularly deflect the narrow beam 25 of the plasma as it reaches the target 53. This can be accomplished by selectively activating portions of integrated portion 101 or by physically rotating integrated portion 101 on a gimbal device.

Although the present invention has been described in what is believed to be a preferred embodiment, it is contemplated that further modifications may be made to increase the operational efficiency of the magnetohydrodynamic purification technique. For example, in a sandwich-like manner. A movable or disposable support is placed between the films to create a target 53.
It is possible to deposit multiple silicon films on top.

Other elemental semiconductors, such as germanium, can be used in place of silicon. Thus, while the invention has been described in accordance with preferred embodiments, it is not limited thereby.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a magnetohydrodynamic device according to the invention. FIG. 2 is a schematic diagram of the arc forming area according to a preferred embodiment 5g of the present invention. FIG. 3 is a block diagram illustrating a method of forming a semiconductor film according to the present invention. 1 Magnetohydrodynamic deposition device 11 K empty housing 13 Upper part 15 Arc forming section, Hall current accelerator. Cold silicon or hot tungsten anode 17 Accelerator magnet 19 Deposition chamber 21 Central section 23 Focusing magnet 25 IB 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 sensing device 77 Hydrogen source, H2 tank 79 Vacuum pump compartment, cryo pump, background in support <10-4 81 Differential ionization + Capture of silicon in situ 83 Beam diameter + W1 of ions in the channel entering the precipitation chamber through the cryo-pump 85 Treatment of the support 87 Heat treatment of the support 89 Precipitating the silicon film to form large polycrystals 10
Forming ~30μ 91 Heat-treating silicon film with H2 97 Deposition of film 99 Retrieval of completed film 101 Amendment of integrated partial procedure for focusing magnet (method) September 27, 1980 Manabu Shiga, Commissioner of the Patent Office 1. Indication of the case Patent application No. 5 S-TVOOST No. 2 Name of the invention Method of manufacturing a magnetohydrodynamic device for separating and depositing materials 3. Relationship with famous case for amendment Patent applicant 4. Agent 〒 107

Claims (1)

[Claims] 1. An apparatus for purifying semiconductor materials by using magnetically accelerated plasma spray in vacuum, comprising: a) a vacuum chamber and associated vacuum pumping equipment; b) magnetohydrodynamics. further comprising a cathode, an anode, an accelerating magnet located adjacent to a portion of the cathode closest to said anode, and at least a portion of which is connected to said cathode. a focusing magnet positioned beyond the anode with respect to; c) a support structure for a plasma generator, wherein the support structure supports said plasma generator in a vacuum chamber; d) said plasma generator. means for supplying electrical power to the plasma generator, where the electrical power is primarily direct current, and which enables the plasma generator to generate a plasma; e) a target surface, where the target surface is a cathode and an anode; f) means for injecting material into the plasma to generate a plasma stream; g) an opening allowing access into the vacuum chamber from the outside, where the opening has sealing means; wherein the implanted material is preferentially ionized by the plasma generator, thereby separating impurities in the material while in the plasma stream. 2. The means for injecting material into the plasma may receive a carrier material, said carrier material combining with impurities present in the semiconductor material in the plasma stream, before the semiconductor material is deposited in the target area. Apparatus according to claim 1, which is effective for separating impurities from a semiconductor material, so that the semiconductor material can be deposited in a state of purity greater than the purity of the semiconductor material before deposition. 3. The means for injecting material into the plasma may further inject a dopant material, whereby said dopant material is applied to the semiconductor material when it is applied to the target area. The device according to item 2. 4. The device of claim 3, wherein the dopant is mixed with a carrier material. 5. The apparatus of claim 2 further comprising robotic means operable to move material to and remove material from the target area. 6. The 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. The device according to claim 2 or 3, wherein the means for injecting the material injects the material adjacent to the cathode. 9. The device according to claim 1 or 3, wherein the cathode is a thermionic cathode. 10. The device according to claim 1 or 2, wherein silicon is injected into the plasma generator during operation of the device. 11. The apparatus of claim 10, wherein the silicon is injected as a liquid compound. 12.Claim 1 in which silicon is implanted into the anode
The device described in item 0. 13.Claim 1 in which silicon is implanted into the cathode
The device described in item 0. 14. The device according to claim 1 or 2, wherein the vacuum pump device comprises a low temperature vacuum pump and an ion vacuum pump device. 15. The apparatus of claim 1, wherein the implanted material comprises silicon and the preferential ionization and separation of impurities from the semiconductor material produces semiconductor grade silicon deposited on the target surface. 16. Claim 1, wherein the coil assembly is provided for condensing material escaping from the plasma stream.
or the device according to item 15. 17. The plasma generator is surrounded by an accelerating magnet, which accelerates the plasma, thereby transporting the material in the plasma away from the plasma generator. equipment. 18. An apparatus for purifying semiconductor metals for use in the formation of semiconductor bonding devices by magnetically accelerated plasma spray in vacuum, comprising: a) a vacuum chamber and associated vacuum pumping equipment; b) a magnetohydrodynamic hole. effect plasma generator, wherein the plasma generator further comprises: a thermionic cathode, an anode, an accelerating magnet located adjacent to the cathode, and a focusing magnet, wherein at least a portion of the focusing magnet is connected to the cathode. c) a support structure for a plasma generator, wherein the support structure supports the plasma generator in a vacuum chamber; d) a support structure for the plasma generator; means for supplying electrical power to said plasma generator, wherein said electrical power is primarily direct current, and said electrical power is capable of generating a plasma stream having ions from said thermionic cathode in said plasma generator; means for supplying the generator;
wherein the semiconductor material has a purity lower than that required for semiconductors; f) a target area, wherein the target area is located within a vacuum chamber, whereby a plasma stream is ejected by said plasma generator and then said 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 break in the vacuum chamber, where the break enters the vacuum chamber from outside the vacuum chamber; accessible and sealing means, wherein the carrier material combines with impurities in the semiconductor material when the carrier material and the semiconductor material are present in the plasma stream, and the material is preferentially ionized. , whereby impurities are separated from a semiconductor material while said material is in a plasma stream. 19. Claim 18 further comprising robotic means, wherein the robotic means is operable to move material to and remove material from the target area.
Apparatus described in section. 20. The device of claim 18, wherein the semiconductor material is silicon and the silicon is implanted in the anode. 21. The device of claim 18, wherein the semiconductor material is silicon and the silicon is implanted adjacent to the cathode. 22. The device according to claim 18, wherein the vacuum pump device comprises a low temperature vacuum pump and an ion vacuum pump device. 23, the semiconductor material supplied to the plasma generator is metallurgical grade silicon, and the preferential ionization and separation of impurities from the semiconductor material produces semiconductor grade silicon deposited in the target area. The device according to scope item 18. 24. Claim 1, wherein the coil assembly is provided for condensing material escaping from the plasma stream.
8 or 23. 25. The plasma generator is surrounded by accelerating magnets, the flux magnets accelerating the plasma so that the material in the plasma is transported away from the plasma generator, as claimed in claim 18 or 23. The device described. 26. An apparatus for purifying semiconductor metals for use in the formation of semiconductor bonding devices by magnetically accelerated plasma spray in vacuum, comprising: a) a vacuum chamber and associated vacuum pumping equipment; b) magnetohydrodynamic plasma. A generator, wherein the plasma generator further comprises: a cathode, an anode, an accelerating magnet located adjacent to a portion of the cathode closest to the anode, and a focusing magnet, wherein at least a portion of the focusing magnet. is located beyond the anode with respect to the cathode; c) a support structure for a plasma generator, wherein the support structure supports the plasma generator in a vacuum chamber; d) the plasma generator means for supplying electrical power to said plasma generator, where said electrical power is primarily direct current, and which electrical power enables said plasma generator to generate a plasma; e) a target surface, where said target surface is connected to said cathode and located beyond the focusing magnet with respect to the anode; f) means for supplying material into the plasma to generate a plasma stream; g) a break opening allowing access to the interior of the break chamber from the outside, where the break the mouth has sealing means; h) a coil assembly, wherein 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, wherein the baffle assembly is located substantially concentrically within the coil assembly and surrounds the plasma to protect and isolate the coil assembly from the plasma. A device characterized by comprising; 27. Apparatus for purifying semiconductor metals for use in the formation of semiconductor bonding devices by magnetically accelerated plasma spray in vacuum, comprising: a) a vacuum chamber and associated vacuum pumping equipment; b) magnetohydrodynamic plasma. A generator, wherein the plasma generator further comprises: a thermionic cathode, an anode, an accelerating magnet located adjacent to the cathode, and a focusing magnet, wherein at least a portion of the focusing magnet focuses the anode with respect to the cathode. c) a support structure for a plasma generator, the support structure supporting said plasma generator within a vacuum chamber; d) means for supplying electrical power to said plasma generator; , where this power is primarily direct current and which enables the plasma generator to generate a plasma with ions from the thermionic cathode; e) a target area, where this target area is in a vacuum; located within a chamber so that a plasma stream can be ejected by the plasma generator and material in the plasma stream can then be deposited in a target area; f) means for injecting material into the plasma stream; g) a vacuum. a chamber aperture, wherein the aperture is accessible into the vacuum chamber from outside the vacuum chamber and has sealing means; h) a coil assembly, wherein the coil assembly is substantially concentric within the focusing magnet; and i) a baffle assembly, wherein the baffle assembly is located substantially concentrically within the coil assembly and cools gas escaping from the plasma, thereby condensing the gas; An apparatus comprising: surrounding the plasma to protect and isolate the coil assembly from the plasma. 28. An apparatus for refining metals by magnetically accelerated plasma spray in vacuum, comprising: a) a vacuum chamber; b) a magnetohydrodynamic plasma generator, wherein the plasma generator comprises: 1) a cathode; 2) an anode; 3) plasma acceleration means located adjacent to said cathode; 4) plasma focusing means, wherein said focusing means is located at least partially beyond said anode with respect to said cathode; 5) said plasma generator is supported within said vacuum chamber; c) means for supplying electrical power to said plasma generator, thereby enabling said plasma generator to generate a plasma stream; d) a target area located within the vacuum chamber to receive material contained in the plasma stream; e) means for injecting material into the plasma stream; and h) a coil assembly, wherein the coil assembly is configured to Apparatus according to claim 1, characterized in that: cooling a gas surrounding and escaping from said plasma, thereby condensing said gas. 29. The apparatus of 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 focusing means comprises a magnet. 32. The apparatus of claim 28, wherein said electrical power consists primarily of direct current. 33. Apparatus according to claim 28 or 32, further comprising a break in the vacuum chamber, the break in making the vacuum chamber accessible from outside the vacuum chamber and including sealing means. 34, further comprising a baffle assembly, wherein the baffle assembly is located substantially concentrically within the coil assembly and surrounds the plasma flow to protect the coil assembly from the plasma flow and 29. Apparatus according to claim 28 for separation from a plasma stream. 35. Claim 28 or 34, wherein said coil assembly is located substantially concentrically within said focusing means.
Apparatus described in section. 36. Claim 3 in which the focusing means comprises a magnet
The device according to item 5. 37. Claim 3 in which the acceleration means comprises a magnet
The device according to item 6. 38. A method for purifying a semiconductor material, comprising: a) preparing a vacuum environment; b) establishing a plasma between an anode and a cathode; c) accelerating the plasma with an accelerating magnet; d) purifying a semiconductor metal. placing the contained substance in the plasma,
e) focusing the plasma stream onto the deposition area with a focusing magnet; f) injecting a carrier substance into the plasma stream, where the carrier substance is present in the semiconductor material in the plasma stream; chemically bonding with impurities in the plasma stream, whereby the semiconductor metal is dissociated from the impurities in the plasma stream prior to said deposition. 39. The method of claim 38, wherein the semiconductor material is injected into the plasma. 40. The method of claim 39, wherein the semiconductor material is implanted as the element in liquid form. 41. The method of claim 38, wherein the semiconductor material is placed in the plasma in the form of a thermionic cathode. 42. Claim 3 in which the semiconductor material is silicon
The method described in Section 8. 43. A method for purifying silicon, comprising: a) preparing a vacuum environment; b) establishing a plasma between a cathode and an anode; c) accelerating the plasma with an accelerating magnet; d) directing the plasma to a target area. e) placing a semiconductor material in the plasma, thereby forming a plasma stream; f) injecting a carrier material into the plasma stream, where the carrier material chemically combining with impurities present in the semiconductor material in the plasma stream; g) extracting the carrier material and the impurities from the vacuum chamber by means of a vacuum pump; 44. The method of claim 43, wherein the semiconductor material is placed in the plasma by forming the cathode as a thermionic cathode made from the semiconductor material. 45. The method of claim 43, wherein the semiconductor material is placed in the plasma by injection means. 46. The method according to claim 43 or 45, wherein the vacuum pump is a combination of a cryogenic pump and an ion pump. 47. Claim 4 in which the semiconductor material is silicon
The method described in Section 5. 48. The method of claim 47, further comprising the step of selectively injecting a dopant into the plasma stream so that the purified silicon has a doped layer.