Patent US3972741A successfully refreshed from Google Patents.
US3972741A
Expired / Lapsed
US
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Multiple p-n junction formation with an alloy droplet
Assignee: General Electric Co
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Filing: 1975-01-30
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Granted: 1976-08-03
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Expires: 1995-01-30
Abstract
Abstract A droplet of alloy material containing at least two semiconductor dopant type elements, each of which has a different ratio of diffusivity, is thermomigrated by a thermal gradient zone melting process through a body of semiconductor material leaving behind a recrystallized region of semiconductor material containing at least two dopant materials therein. Following thermomigration of the droplet, the body of semiconductor material is subjected to a post-thermomigration heat treatment at an appropriate temperature to allow the dopants in the region produced by thermomigration to diffuse substantially perpendicular to that region into the remaining material of the body. The slower diffusing dopant species is largely left behind in the region to form a region of conductivity type determined by the slower diffusing species while the faster diffusing species will diffuse outward and form an annulus around the recrystallized region of a conductivity type determined by the faster diffusing species. The original semiconductor material of the body will form a third conductivity type region.
Inventors
- 👤 Thomas R. Anthony
- 👤 Harvey E. Cline
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:21
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/16; H10P95/00; H10P95/50
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
414 words
A process for making a semiconductor device comprising the process steps of: a. selecting a body of semiconductor material having a predetermined level of resistivity, a predetermined type conductivity and two major opposed surfaces which are, respectively, the top and bottom surfaces thereof, at least one of the major surfaces having a preferred planar crystal structure orientation and a vertical axis which is substantially parallel with a first axis of the crystal structure and substantially perpendicular to the at least one major surface having the preferred crystal planar orientation; b. depositing a predetermined thickness of a layer of material of a predetermined composition having at least two different dopant impurities therein, suitable for doping a predetermined semiconductor material, on a predetermined portion of the at least one major surface of the body having the preferred crystal planar orientation, the layer of material having a predetermined geometrical configuration, and each dopant impurity material having a different rate of diffusivity in the semiconductor material; c. heating the body and the material deposited thereon to an elevated temperature sufficient to form a melt of each layer of deposited material and portion of the semiconductor material in contact therewith; d. establishing a temperature gradient across the body between the two opposed major surfaces, wherein the surface upon which the melt is formed is at the lower temperature; e. migrating each melt through the entire body from the surface of lower temperature to the surface of higher temperature to form a region of recrystallized semiconductor material of the body having solid solubility of the deposited material therein, and f. heating the processed body to an elevated temperature for an elapsed period of time sufficient to allow a portion of the dopant impurity materials to diffuse outward from the region of recrystallized material into the mutually adjacent semiconductor material of the body to form a second region of diffused semiconductor material of the body having a second predetermined type conductivity and a predetermined level of resistivity, and the type conductivity and level of resistivity being determined by the dopant impurity material having the highest diffusivity, the level of concentration of the dopant impurity material in the second region being substantially the same throughout any given plane which is substantially parallel to the abutting surfaces of the first and second regions and the level of resistivity in the second region increasing with increasing distance from the interface of the first and second region in any plane which is substantially perpendicular thereto.
Claim 2
Dependent Claim
414 words
A process for making a semiconductor device comprising the process steps of: a. selecting a body of semiconductor material having a predetermined level of resistivity, a predetermined type conductivity and two major opposed surfaces which are, respectively, the top and bottom surfaces thereof, at least one of the major surfaces having a preferred planar crystal structure orientation and a vertical axis which is substantially parallel with a first axis of the crystal structure and substantially perpendicular to the at least one major surface having the preferred crystal planar orientation; b. depositing a predetermined thickness of a layer of material of a predetermined composition having at least two different dopant impurities therein, suitable for doping a predetermined semiconductor material, on a predetermined portion of the at least one major surface of the body having the preferred crystal planar orientation, the layer of material having a predetermined geometrical configuration, and each dopant impurity material having a different rate of diffusivity in the semiconductor material; c. heating the body and the material deposited thereon to an elevated temperature sufficient to form a melt of each layer of deposited material and portion of the semiconductor material in contact therewith; d. establishing a temperature gradient across the body between the two opposed major surfaces, wherein the surface upon which the melt is formed is at the lower temperature; e. migrating each melt through the entire body from the surface of lower temperature to the surface of higher temperature to form a region of recrystallized semiconductor material of the body having solid solubility of the deposited material therein, and f. heating the processed body to an elevated temperature for an elapsed period of time sufficient to allow a portion of the dopant impurity materials to diffuse outward from the region of recrystallized material into the mutually adjacent semiconductor material of the body to form a second region of diffused semiconductor material of the body having a second predetermined type conductivity and a predetermined level of resistivity, and the type conductivity and level of resistivity being determined by the dopant impurity material having the highest diffusivity, the level of concentration of the dopant impurity material in the second region being substantially the same throughout any given plane which is substantially parallel to the abutting surfaces of the first and second regions and the level of resistivity in the second region increasing with increasing distance from the interface of the first and second region in any plane which is substantially perpendicular thereto.
Claim 3
Dependent Claim
48 words
The process of claim 1 including practicing the process step prior to the depositing of the layer of material of selectively etching the predetermined portion of the major surface of the body to form a depression therein of a predetermined geometrical configuration into which the material is deposited.
Claim 4
Dependent Claim
13 words
The process of claim 2 wherein the layer of material is vapor deposited.
Claim 5
Dependent Claim
15 words
The process of claim 3 wherein the vapor deposited material is substantially free of oxygen.
Claim 6
Dependent Claim
21 words
The process of claim 2 wherein the preferred planar crystal orientation is (111), and the first crystal axis is <111 >.
Claim 7
Dependent Claim
26 words
The process of claim 5 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 8
Dependent Claim
28 words
The process of claim 6 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 9
Dependent Claim
29 words
The process of claim 6 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 10
Dependent Claim
47 words
The process of claim 5 wherein each layer of material has a preferred wire-like geometrical configuration oriented in a preferred crystal wire direction which is at least one selected from the group consisting of <011 >, <101 >, <110 >, <112 >, <211 > and <121 >.
Claim 11
Dependent Claim
26 words
The process of claim 9 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 12
Dependent Claim
28 words
The process of claim 10 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 13
Dependent Claim
29 words
The process of claim 10 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 14
Dependent Claim
17 words
The process of claim 9 wherein the width of the migrating melt is less than 500 microns.
Claim 15
Dependent Claim
21 words
The process of claim 2 wherein the preferred planar crystal orientation is (100), and the first crystal axis is <100 >.
Claim 16
Dependent Claim
26 words
The process of claim 14 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 17
Dependent Claim
28 words
The process of claim 15 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 18
Dependent Claim
29 words
The process of claim 15 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 19
Dependent Claim
39 words
The process of claim 14 wherein each deposited layer has a preferred wire-like configuration oriented in a preferred crystal wire direction which is at least one selected from the group consisting of < 011 > and < 011 >.
Claim 20
Dependent Claim
26 words
The process of claim 18 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 21
Dependent Claim
28 words
The process of claim 19 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 22
Dependent Claim
29 words
The process of claim 19 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 23
Dependent Claim
17 words
The process of claim 18 wherein the width of the migrating melt is less than 100 microns.
Claim 24
Dependent Claim
43 words
The process of claim 2 wherein the preferred planar crystal orientation is (110); each layer of material has a preferred wire-like geometrical configuration oriented in a preferred crystal wire direction of < 110 >, and the first crystal axis is < 110 >.
Claim 25
Dependent Claim
26 words
The process of claim 23 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 26
Dependent Claim
29 words
The process of claim 24 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 27
Dependent Claim
28 words
The process of claim 23 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 28
Dependent Claim
17 words
The process of claim 23 wherein the width of the migrating melt is less than 150 microns.
Claim 29
Dependent Claim
21 words
The process of claim 2 wherein the preferred planar orientation is (110), and the first crystal axis is < 110 >.
Claim 30
Dependent Claim
26 words
The process of claim 28 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 31
Dependent Claim
28 words
The process of claim 28 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 32
Dependent Claim
29 words
The process of claim 29 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 33
Dependent Claim
116 words
The process of claim 1 wherein migrating each melt is practiced for a period of time sufficient to migrate the melt a predetermined distance into the body less than the thickness of the body and then stopping the migration of the melt, establishing a new thermal gradient substantially parallel with the first crystal axis wherein the major surface on which the melt was formed initially is now at the higher temperature and migrating each melt substantially through the first region of recrystallized material of the body to the same major surface to form a second region comprising substantially the recrystallized material of the first region having solid solubility of the material of the deposited layer therein.
Claim 34
Dependent Claim
48 words
The process of claim 32 including practicing the process step prior to the depositing of the layer of material of selectively etching the predetermined portion of the major surface of the body to form a depression therein of a predetermined geometrical configuration into which the material is deposited.
Claim 35
Dependent Claim
13 words
The process of claim 33 wherein the layer of material is vapor deposited.
Claim 36
Dependent Claim
22 words
The process of claim 33 wherein the preferred planar crystal orientation is (111), and the first crystal axis is < 111 >.
Claim 37
Dependent Claim
26 words
The process of claim 35 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 38
Dependent Claim
28 words
The process of claim 36 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 39
Dependent Claim
29 words
The process of claim 36 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 40
Dependent Claim
53 words
The process of claim 35 wherein each layer of material has a preferred wire-like geometrical configuration oriented in a preferred crystal wire direction which is at least one selected from the group consisting of < 011 >, < 101 >, < 110 >, < 112 >, < 211 > and < 121 >.
Claim 41
Dependent Claim
26 words
The process of claim 39 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 42
Dependent Claim
28 words
The process of claim 40 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 43
Dependent Claim
29 words
The process of claim 40 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 44
Dependent Claim
17 words
The process of claim 39 wherein the width of the migrating melt is less than 500 microns.
Claim 45
Dependent Claim
22 words
The process of claim 33 wherein the preferred planar crystal orientation is (100), and the first crystal axis is < 100 >.
Claim 46
Dependent Claim
26 words
The process of claim 44 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 47
Dependent Claim
28 words
The process of claim 45 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 48
Dependent Claim
29 words
The process of claim 45 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 49
Dependent Claim
39 words
The process of claim 33 wherein each deposited layer has a preferred wire-like configuration oriented in a preferred crystal wire direction which is at least one selected from the group consisting of < 011 > and < 011 >.
Claim 50
Dependent Claim
26 words
The process of claim 48 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 51
Dependent Claim
28 words
The process of claim 49 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 52
Dependent Claim
29 words
The process of claim 49 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 53
Dependent Claim
17 words
The process of claim 48 wherein the width of the migrating melt is less than 100 microns.
Claim 54
Dependent Claim
43 words
The process of claim 33 wherein the preferred planar crystal orientation is (110); each layer of material has a preferred wire-like geometrical configuration oriented in a preferred crystal wire direction of < 110 >, and the first crystal axis is < 110 >.
Claim 55
Dependent Claim
26 words
The process of claim 53 wherein the material of the body is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.
Claim 56
Dependent Claim
29 words
The process of claim 54 wherein the material of the body is boron doped silicon of P-type conductivity, and the layer of material comprises tin, aluminum, antimony and phosphorus.
Claim 57
Dependent Claim
28 words
The process of claim 53 wherein the material of the body is antimony doped silicon of N-type conductivity, and the layer of material comprises tin, aluminum and antimony.
Claim 58
Dependent Claim
17 words
The process of claim 53 wherein the width of the migrating melt is less than 150 microns.
Claim 59
Dependent Claim
15 words
The process of claim 35 wherein the vapor deposited material is substantially free of oxygen.
References Cited (Backward Citations)
US2701326A
Cited
US2813048A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |