US4682564A — Magnetoplasmadynamic processor, applications ther…

Claim 1

Independent Claim 191 words

An apparatus for depositing materials in layers by using a plasma beam electromagnetically accelerated in a vacuum comprising: (a) a vacuum chamber and associated vacuum pumping apparatus; (b) a magnetoplasmadynamic plasma generator, the plasma generator further comprising cathode means anode means a cathode magnet located in substantially surrounding relation to said cathode means; a trimmer magnet located in substantially surrounding relation to said anode means; a focusing magnet, at least part of which is located beyond the anode means with respect to the cathode means; (c) a shielded plasma generator support structure, the support structure supporting the plasma generator within the vacuum chamber; (d) a means to supply the plasma generator with electric power, the electric power being primarily direct current and the power enabling the plasma generator to create a plasma; (e) a target surface, the target surface being located beyond the focusing magnet with respect to the cathode and anode; and (f) means for injecting one or more of a plurality of materials at a location within said vacuum chamber so as to facilitate the creation of a plasma stream; (g) said plasma stream impinging upon said target surface.

Claim 2

Independent Claim 191 words

An apparatus for depositing materials in layers by using a plasma beam electromagnetically accelerated in a vacuum comprising: (a) a vacuum chamber and associated vacuum pumping apparatus; (b) a magnetoplasmadynamic plasma generator, the plasma generator further comprising cathode means anode means a cathode magnet located in substantially surrounding relation to said cathode means; a trimmer magnet located in substantially surrounding relation to said anode means; a focusing magnet, at least part of which is located beyond the anode means with respect to the cathode means; (c) a shielded plasma generator support structure, the support structure supporting the plasma generator within the vacuum chamber; (d) a means to supply the plasma generator with electric power, the electric power being primarily direct current and the power enabling the plasma generator to create a plasma; (e) a target surface, the target surface being located beyond the focusing magnet with respect to the cathode and anode; and (f) means for injecting one or more of a plurality of materials at a location within said vacuum chamber so as to facilitate the creation of a plasma stream; (g) said plasma stream impinging upon said target surface.

Claim 3

Dependent Claim 28 words

The apparatus of claim 1, further including an access door enabling access to the inside of the vacuum chamber from the outside, the access door having sealing means.

Claim 4

Dependent Claim 34 words

The apparatus of claim 1 wherein the means for injecting materials into the plasma is further adapted to inject dopant material so that the dopant material may be selectively applied at said target surface.

Claim 5

Dependent Claim 25 words

The apparatus of claim 3 wherein the means for injecting one or more of a plurality of materials injects the materials adjacent to the cathode.

Claim 6

Dependent Claim 85 words

The apparatus of claim 3 wherein means are provided so that the directional orientation of a flux pattern of the focusing magnet can be rotated with respect to an initial plasma center line, the initial plasma center line being a line passing through a center of the cathode and a center of the anode, the rotation of the directional orientation of the flux pattern of the focusing magnet being effective to enable the apparatus to deposit material selectively at various portions of the target surface.

Claim 7

Dependent Claim 85 words

The apparatus of claim 4 wherein means are provided so that the directional orientation of a flux pattern of the focusing magnet can be rotated with respect to an initial plasma center line, the initial plasma center line being a line passing through a center of the cathode and a center of the anode, the rotation of the directional orientation of the flux pattern of the focusing magnet being effective to enable the apparatus to deposit material selectively at various portions of the target surface.

Claim 8

Dependent Claim 24 words

The apparatus of claim 6 further comprising a robot means, the robot means being operable to move materials to and from the target surface.

Claim 9

Dependent Claim 10 words

The apparatus of claim 1, utilized to form semiconductor devices.

Claim 10

Dependent Claim 13 words

The apparatus of claim 8 wherein the semiconductor devices are silicon solar cells.

Claim 11

Dependent Claim 13 words

The apparatus of claim 1 wherein the cathode means is a thermionic cathode.

Claim 12

Dependent Claim 42 words

The apparatus of claim 10 wherein the thermionic cathode further includes a buffer means mounted in surrounding relation thereto, said buffer means defining a buffer cavity adjacent a tip portion of said thermionic cathode, and means supplying gas to said buffer cavity.

Claim 13

Dependent Claim 19 words

The apparatus of claim 1 wherein silicon is injected into the plasma generator during the operation of the apparatus.

Claim 14

Dependent Claim 14 words

The apparatus of claim 12 wherein the silicon is injected as a fluid compound.

Claim 15

Dependent Claim 16 words

The apparatus of claim 12 wherein the silicon is injected as elemental silicon in liquid form.

Claim 16

Dependent Claim 14 words

The apparatus of claim 12 wherein the silicon is injected through the anode means.

Claim 17

Dependent Claim 14 words

The apparatus of claim 12 wherein the silicon is injected through the cathode means.

Claim 18

Dependent Claim 19 words

The apparatus of claim 3, wherein the dopant is mixed with the plasma stream when the dopant is injected.

Claim 19

Dependent Claim 19 words

The apparatus of claim 8 wherein top terminals may be deposited on the semiconductor devices by the plasma generator.

Claim 20

Dependent Claim 16 words

The apparatus of claim 18 wherein the top terminals are formed by the deposition of aluminum.

Claim 21

Dependent Claim 48 words

The apparatus of claim 18 wherein said deposition at the top terminals is accomplished by first having the robot means first place a solid template over the target area said template having appropriate deposition openings extending therethrough and then depositing terminal material by means of the plasma generator.

Claim 22

Dependent Claim 11 words

The apparatus of claim 20, wherein said terminal material comprises aluminum.

Claim 23

Dependent Claim 21 words

The apparatus according to claim 1 wherein the vacuum pumping apparatus comprises a cryogenic vacuum pump and an ion vacuum pump.

Claim 24

Dependent Claim 15 words

The apparatus of claim 22, wherein said vacuum pumping apparatus further includes a sorption pump.

Claim 25

Dependent Claim 33 words

The apparatus of claim 11, wherein insulation means is provided between said cathode means and said buffer means, and said means for supplying gas to said buffer cavity extends through said insulation means.

Claim 26

Dependent Claim 19 words

The apparatus of claim 24, further wherein cooling means is provided for said cathode means and said buffer means.

Claim 27

Dependent Claim 27 words

The apparatus of claim 25, wherein said cooling means comprises tube means extending within said cathode means and said buffer means, and means for supplying coolant therethrough.

Claim 28

Dependent Claim 44 words

The apparatus of claim 1, wherein said cathode magnet is controllable to establish a predetermined magnetic field strength at a tip portion of said cathode means, the magnet field formed thereby diverging away from the cathode means in the direction of said anode means.

Claim 29

Dependent Claim 29 words

The apparatus of claim 27, wherein said anode means comprises a ring-like member and said trimmer magnet is adjustable to control the magnetic field within the ring-like anode means.

Claim 30

Dependent Claim 24 words

The apparatus of claim 1, further including upstream vacuum insulator/isolator means mounted in said vacuum chamber between said cathode means and said anode means.

Claim 31

Dependent Claim 65 words

The apparatus of claim 29, wherein said upstream vacuum insulator/isolator means comprises a plurality of discs, each said disc including an outer diameter and an opening therethrough, said openings sequentially increasing in diameter from said cathode means to said anode means with a disc closest to said cathode means having the smallest opening and a disc closest to said anode means having the largest opening.

Claim 32

Dependent Claim 24 words

The apparatus of claim 29, further including downstream vacuum insulator/isolator means mounted to said vacuum chamber between said anode means and said target surface.

Claim 33

Dependent Claim 22 words

The apparatus of claim 31, wherein said downstream vacuum insulator/isolator means comprises a plurality of truncated conical rings of substantially identical configuration.

Claim 34

Dependent Claim 65 words

The apparatus of claim 32 wherein said upstream vacuum insulator/isolator means comprises a plurality of discs, each said disc including an outer diameter and an opening therethrough, said openings sequentially increasing in diameter from said cathode means to said anode means with a disc closest to said cathode means having the smallest opening and a disc closest to said anode means having the largest opening.

Claim 35

Dependent Claim 13 words

The apparatus of claim 1, wherein said anode means includes cooling means therefor.

Claim 36

Dependent Claim 13 words

The apparatus of claim 1, wherein said target surface includes cooling means therefor.

Claim 37

Dependent Claim 28 words

The apparatus of claim 33, wherein said anode means further includes conduit means for supplying feed gas thereto, said conduit means being surrounded by further vacuum insulator/isolator means.

Claim 38

Dependent Claim 51 words

The apparatus of claim 36, wherein said anode means further includes conduit means for supplying dopant gas thereto, said dopant gas conduit means being surrounded by still further vacuum insulator/isolator means, one of said dopant gas and feed gas vacuum insulator/isolator means further enclosing power lead means for said anode means.

Claim 39

Dependent Claim 174 words

A magnetoplasmadynamic processor comprising: (a) an elongated vacuum chamber having a longitudinal axis therethrough; (b) cathode-buffer means mounted in said vacuum chamber substantially aligned with said longitudinal axis and including: (i) a cathode rod; (ii) a buffer mounted in surrounding spaced relation to said cathode rod; and (iii) gas supply means for supplying gas to a buffer cavity formed between said cathode rod and said buffer; (c) an anode-ionizer mounted in said vacuum chamber substantially aligned with said longitudinal axis and including: (i) an inner ring portion; (ii) an outer substantially cylindrical portion in surrounding relation to said inner ring portion; (iii) a gap defined between said inner ring portion and said outer substantially cylindrical portion; and (iv) means for supplying gas to said gap; (d) accelerating magnet means including: (i) a cathode magnet substantially surrounding said cathode buffer means, and (ii) a trimmer magnet substantially surrounding said anode-ionizer, and (e) upstream vacuum insulator/isolator means mounted in said vacuum chamber between said cathode-buffer means and said anode-ionizer and substantially aligned with said longitudinal axis.

Claim 40

Dependent Claim 174 words

A magnetoplasmadynamic processor comprising: (a) an elongated vacuum chamber having a longitudinal axis therethrough; (b) cathode-buffer means mounted in said vacuum chamber substantially aligned with said longitudinal axis and including: (i) a cathode rod; (ii) a buffer mounted in surrounding spaced relation to said cathode rod; and (iii) gas supply means for supplying gas to a buffer cavity formed between said cathode rod and said buffer; (c) an anode-ionizer mounted in said vacuum chamber substantially aligned with said longitudinal axis and including: (i) an inner ring portion; (ii) an outer substantially cylindrical portion in surrounding relation to said inner ring portion; (iii) a gap defined between said inner ring portion and said outer substantially cylindrical portion; and (iv) means for supplying gas to said gap; (d) accelerating magnet means including: (i) a cathode magnet substantially surrounding said cathode buffer means, and (ii) a trimmer magnet substantially surrounding said anode-ionizer, and (e) upstream vacuum insulator/isolator means mounted in said vacuum chamber between said cathode-buffer means and said anode-ionizer and substantially aligned with said longitudinal axis.

Claim 41

Dependent Claim 20 words

The processor of claim 38, wherein said cathode-buffer means further includes insulation means between said cathode rod and said buffer.

Claim 42

Dependent Claim 35 words

The processor of claim 39, wherein said gas supply means includes thread-like passageways extending through said insulation means and communicating with said buffer cavity whereby said gas is caused to swirl in said buffer cavity.

Claim 43

Dependent Claim 18 words

The processor of claim 40, wherein said cathode rod includes a pointed tip extending into said buffer cavity.

Claim 44

Dependent Claim 28 words

The processor of claim 38, wherein said buffer includes orifice means communicating said buffer cavity with said vacuum chamber, said orifice means being substantially aligned with said axis.

Claim 45

Dependent Claim 25 words

The processor of claim 42, wherein said orifice means is of a size designed to maintain a back pressure of gas within said buffer cavity.

Claim 46

Dependent Claim 66 words

The processor of claim 38, wherein said inner ring portion of said anode-ionizer includes a first end substantially flush with a first end of said outer substantially cylindrical portion and said inner ring portion is significantly shorter in the direction of said axis then said outer substantially cylindrical portion whereby a second end of said inner ring portion lies completely within said outer substantially cylindrical portion.

Claim 47

Dependent Claim 92 words

The invention of claim 44, wherein said outer substantially cylindrical portion includes first and second orifices communicating the exterior thereof with said gap, and said means for supplying gas to said gap comprises: (a) first conduit means sealingly attached to said first orifice and communicating a first gas to said gap; (b) first anode vacuum insulator/isolator means surrounding said first conduit means; (c) second conduit means sealingly attached to said second orifice and communicating a second gas to said gap; and (d) second anode vacuum insulator/isolator means surrounding said second conduit means.

Claim 48

Dependent Claim 63 words

The invention of claim 45, wherein said first and second anode insulator/isolator means comprise: (a) an insulative covering attached to a respective conduit means; (b) first cylindrical means surrounding said insulative covering and spaced therefrom; (c) second cylindrical means surrounding said first cylindrical means and spaced therefrom; and (d) means for structurally supporting said first and second cylindrical means in said spaced relation.

Claim 49

Dependent Claim 32 words

The invention of claim 38, wherein said vacuum chamber has an annular stepped configuration adjacent said cathode-buffer means and said cathode magnet is located in overlying relation to said annular stepped configuration.

Claim 50

Dependent Claim 63 words

The invention of claim 38, wherein said upstream vacuum insulator/isolator means comprises a plurality of discs, each said disc including an outer diameter and an opening therethrough, said openings sequentially increasing in diameter from said cathode-buffer means to said anode-ionizer with a disc closest to said cathode-buffer means having the smallest opening and a disc closest to said anode-ionizer having the largest opening.

Claim 51

Dependent Claim 31 words

The invention of claim 38, wherein said vacuum chamber extends a substantial distance beyond said anode-ionizer, and further wherein said processor includes downstream vacuum insulator/isolator means mounted within said vacuum chamber.

Claim 52

Dependent Claim 27 words

The invention of claim 49, wherein said downstream vacuum insulator/isolator means comprises a plurality of substantially identical truncated conical segments mounted about said axis beyond said anode-ionizer.

Claim 53

Dependent Claim 19 words

The invention of claim 50, wherein said processor further comprises focusing magnet means surrounding said downstream vacuum insulator/isolator means.

Claim 54

Dependent Claim 32 words

The invention of claim 51, wherein said focusing magnet means comprises a plurality of focusing magnets attached to the exterior of said vacuum chamber in surrounding relation to said truncated conical segments.

Claim 55

Dependent Claim 20 words

The invention of claim 45, wherein said first gas comprises semiconductor feed gas and said second gas comprises dopant gas.

Claim 56

Dependent Claim 39 words

The invention of claim 45, wherein a target means is provided in said vacuum chamber aligned with said axis at a location spaced from said anode-ionizer, and a plasma stream formed by said processor impinges upon said target means.

Claim 57

Dependent Claim 23 words

The invention of claim 54, wherein constituent ions from said first and second gases combine at said target means to form a compound.

Claim 58

Dependent Claim 23 words

The invention of claim 54, wherein constituent ions from said first and second gases combine at said target means to form a mixture.

Claim 59

Dependent Claim 23 words

The invention of claim 54, wherein constituent ions from said first and second gases combine at said target means to form an alloy.

Claim 60

Dependent Claim 56 words

The invention of claim 54, wherein some constituent ions from said first and second gases combine at said target to form one of a compound, a mixture and an alloy, and wherein said processor further includes pumping means for pumping from said plasma stream and vacuum chamber constituent un-ionized particles from said first and second gases.

Claim 61

Dependent Claim 13 words

The invention of claim 58, wherein said pumping means comprises mechanical pump means.

Claim 62

Dependent Claim 13 words

The invention of claim 58, wherein said pumping means comprises ion pump means.

Claim 63

Dependent Claim 13 words

The invention of claim 58, wherein said pumping means comprises sorption pump means.

Claim 64

Dependent Claim 15 words

The invention of claim 58, wherein said pumping means comprises mechanical and ion pump means.

Claim 65

Dependent Claim 15 words

The invention of claim 58, wherein said pumping means comprises mechanical and sorption pump means.

Claim 66

Dependent Claim 15 words

The invention of claim 58, wherein said pumping means comprises ion and sorption pump means.

Claim 67

Dependent Claim 16 words

The invention of claim 58, wherein said pumping means comprises mechanical, ion and sorption pump means.

Claim 68

Dependent Claim 13 words

The invention of claim 54, further including cooling means for said target means.

Claim 69

Dependent Claim 27 words

The invention of claim 78, wherein said cooling means comprises conduit means extending through said target means and supply means for supplying coolant to said conduit means.

Claim 70

Dependent Claim 13 words

The invention of claim 38, further including cooling means for said cathode rod.

Claim 71

Dependent Claim 12 words

The invention of claim 68, further comprising cooling means for said buffer.

Claim 72

Dependent Claim 12 words

The invention of claim 69, further comprising, cooling means for said anode-ionizer.

Claim 73

Dependent Claim 18 words

The invention of claim 70, further comprising cooling means for said means for supplying gas to said gap.

Claim 74

Dependent Claim 29 words

The invention of claim 45, wherein said first and second orifices open into said gap tangentially whereby said first and second gases are caused to swirl within said gap.

Claim 75

Dependent Claim 20 words

The invention of claim 38, wherein collection means is provided in said vacuum chamber for ions of predetermined molecular weights.

Claim 76

Dependent Claim 27 words

The invention of claim 73, wherein said collection means comprises a first collector for high molecular weight ions and a second collector for low molecular weight ions.

Claim 77

Dependent Claim 39 words

The invention of claim 73, wherein said first collector comprises a substantially conically shaped member mounted along said axis and oriented with a tip portion thereof facing said anode-ionizer and a base portion thereof facing away from said anode-ionizer.

Claim 78

Dependent Claim 16 words

The invention of claim 75, wherein said second collector comprises a flat plate facing said anode-ionizer.

Claim 79

Dependent Claim 22 words

The invention of claim 76, wherein said second collector further comprises a substantially circular flat plate with a hole centrally located therein.

Claim 80

Dependent Claim 25 words

The invention of claim 77, wherein said first collector extends through said hole in said second collector and is substantially perpendicular to said second collector.

Claim 81

Dependent Claim 29 words

The invention of claim 51, further including a plurality of anode elements and cathode elements mounted within said vacuum chamber in surrounding relation to said downstream vacuum insulator/isolator means.

Claim 82

Dependent Claim 39 words

The invention of claim 79, wherein said anode elements and cathode elements are mounted in alternating fashion with at least one anode element located between two cathode elements and at least one cathode element located between two anode elements.

Claim 83

Dependent Claim 19 words

The invention of claim 80, wherein said anode elements and cathode elements are surrounded by said focusing magnet means.

Claim 84

Dependent Claim 53 words

The invention of claim 81, wherein said focusing magnet means is operative to: (a) focus a plasma stream formed by said processor onto target means located in said vacuum chamber, and (b) interact with said cathode elements and anode elements to form an ion pump which pumps atoms or molecules from said chamber.

Claim 85

Dependent Claim 56 words

The invention of claim 60 wherein said ion pump means comprises: (a) a plurality of anode elements and cathode elements mounted in alternating relation in said vacuum chamber between said anode-ionizer and said target means and in surrounding relation to said plasma stream, and (b) ion pump magnet means surrounding said anode elements and cathode elements.

Claim 86

Dependent Claim 25 words

The invention of claim 83, wherein said ion pump magnet means further comprises focusing magnet means for focusing said plasma stream onto said target means.

Claim 87

Dependent Claim 24 words

The invention of claim 54, wherein constituent ions from said first and second gases combine at said target means to form a doped semiconductor.

Claim 88

Dependent Claim 28 words

The invention of claim 58 wherein at least one of said first and second gases comprises a plurality of gases which are non-reactive with respect to one another.

Claim 89

Dependent Claim 23 words

The invention of claim 54, wherein constituent ions from said first and second gases combine at said target means to form a semi-conductor.

Claim 90

Dependent Claim 110 words

The invention of claim 38, wherein the ion flux rate of a plasma stream formed by said processor is determined by the critical mass flow rate of ions in said plasma stream, said critical mass flow rate (m I ) cr being defined by the formula: (m.sub.I).sub.cr =(F.sub.EM /V.sub.cr) where F EM =electromagnetic reaction force on said accelerating magnet means and on all current carrying structure within said vacuum chamber V cr =critical exhaust velocity of said plasma stream which equals the Alfven velocity and, further, wherein gas is supplied to said gap by said gas supplying means at a sufficient rate to thereby provide the desired ion flux rate.

Claim 91

Dependent Claim 191 words

The invention of claim 38 wherein: (a) said processor further includes focusing magnet means located beyond said anode-ionizer with respect to said cathode-buffer means; (b) said processor forms a plasma stream; (c) said plasma stream is composed of a cathode jet and an anode sheath which converge at a predetermined distance L beyond said anode-ionizer to form an electromagnetic throat, said predetermined distance L being defined by the formula: ##EQU83## where Φ A =πR A 2 (B z ) A R A =an inner radius of the anode-ionizer (B z ) A =average strength of the axial magnetic field at said anode-ionizer σ=electrical conductivity of gas in said cathode jet. k=Boltzman's constant T=Gas (electron) temperature m=mass flow rate in the cathode jet. m a =mass of an atom of gas flowing in the cathode jet. I=current flowing thru the cathode jet. e=charge in the electron. ##EQU84## γ=ratio of specific heats; (d) and further wherein said term (B z ) A is a function of magnetic fields created by said cathode magnet, said trimmer magnet and said focusing magnet means, adjustment of said magnetic fields being operative to adjust said predetermined distance.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-07-27	1991-01-26	1991-07-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-07-27	1995-01-26	1995-07-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-07-27	1999-01-26	1999-07-28	$7700.00	Window Closed / Lapsed

Magnetoplasmadynamic processor, applications thereof and methods

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