Patent US4999560A successfully refreshed from Google Patents.
US4031607A
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Minority carrier isolation barriers for semiconductor devices
Assignee: General Electric Co
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Filing: 1976-04-29
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Granted: 1977-06-28
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Expires: 1996-04-29
Abstract
Abstract A minority carrier isolation barrier in a body of semiconductor material is formed by the migration of a suitable metal-rich liquid zone of an impurity material through the semiconductor body. A thermal gradient zone melting process is practiced to produce a region of recrystallized semiconductor material of the body having solid solubility of an impurity therein to impart a level of minority carrier lifetime thereto which is different from that level of minority carrier lifetime of the body.
Inventors
- 👤 Harvey E. Cline
- 👤 Thomas R. Anthony
- 👤 Richard A. Kokosa
- 👤 E. Duane Wolley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:20
CPC Classifications
H; H10; H10P; H10P95/00; C; C30; C30B; C30B13/00; C30B13/02; H10D; H10D84/00; H10D84/60; H10D84/676; H10D99/00; H10P10/00; H10P10/12; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; Y; Y10; Y10S; Y10S148/00; Y10S148/088
Claims Analysis
Total Claims: 58
Claim 1
Independent Claim
322 words
A process for forming a region of a selected minority carrier lifetime in a body of semiconductor material comprising the steps of: (a) selecting a body of single crystal semiconductor material having two major opposed surfaces comprising, respectively, the top and bottom surfaces thereof, a selected level of resistivity, a selected type conductivity, and a preferred planar crystal structure orientation of at least one of the major opposed surfaces, the planar crystal structure orientation is one selected from the group consisting of (111), (100) and (110); (b) orienting the body so that the vertical axis of the body is substantially aligned with a first axis of the crystal structure which is substantially perpendicular to the at least one major opposed surface having the preferred planar crystal structure orientation; (c) disposing at least one metal wire of a selected metal composition comprising at least one material suitable for controlling the minority carrier lifetime in a body of semiconductor material on the surface having a preferred planar orientation, each metal wire having a preferred stable wire direction which is dependent upon the planar orientation of the major surface; (d) heating the body and the at least one metal wire to a temperature sufficient to form a melt of metal-rich semiconductor material on the major surface of the body; (e) establishing a thermal gradient substantially parallel with the vertical axis of the body and the first crystal axis of the material of the body; (f) thermal migrating each melt into the body a predetermined distance from the one major surface parallel with the first crystal axis in the direction of the higher temperature of the thermal gradient to form a region of recrystallized semiconductor material of the body having solid solubility of the metal of the melt, as determined by the temperature of migration, and a level of minority carrier lifetime which is different from that minority carrier level of the material of the body.
Claim 2
Dependent Claim
322 words
A process for forming a region of a selected minority carrier lifetime in a body of semiconductor material comprising the steps of: (a) selecting a body of single crystal semiconductor material having two major opposed surfaces comprising, respectively, the top and bottom surfaces thereof, a selected level of resistivity, a selected type conductivity, and a preferred planar crystal structure orientation of at least one of the major opposed surfaces, the planar crystal structure orientation is one selected from the group consisting of (111), (100) and (110); (b) orienting the body so that the vertical axis of the body is substantially aligned with a first axis of the crystal structure which is substantially perpendicular to the at least one major opposed surface having the preferred planar crystal structure orientation; (c) disposing at least one metal wire of a selected metal composition comprising at least one material suitable for controlling the minority carrier lifetime in a body of semiconductor material on the surface having a preferred planar orientation, each metal wire having a preferred stable wire direction which is dependent upon the planar orientation of the major surface; (d) heating the body and the at least one metal wire to a temperature sufficient to form a melt of metal-rich semiconductor material on the major surface of the body; (e) establishing a thermal gradient substantially parallel with the vertical axis of the body and the first crystal axis of the material of the body; (f) thermal migrating each melt into the body a predetermined distance from the one major surface parallel with the first crystal axis in the direction of the higher temperature of the thermal gradient to form a region of recrystallized semiconductor material of the body having solid solubility of the metal of the melt, as determined by the temperature of migration, and a level of minority carrier lifetime which is different from that minority carrier level of the material of the body.
Claim 3
Dependent Claim
51 words
The process of claim 3 including practicing the following additional process step prior to the disposing at least one metal wire on the surface of selectively etching a selective portion of the major surface of the body to form a depression therein into which the metal of the melt is deposited.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein the metal of the melt is vapor deposited.
Claim 5
Dependent Claim
24 words
The process of claim 2 wherein the metal comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 6
Dependent Claim
30 words
The process of claim 1 wherein thermal migrating of each melt is practiced until the region which is formed thereby extends between, and terminates in, the two major opposed surfaces.
Claim 7
Dependent Claim
30 words
The process of claim 2 wherein thermal migrating of each melt is practiced until the region which is formed thereby extends between, and terminates in, the two major opposed surfaces.
Claim 8
Dependent Claim
30 words
The process of claim 3 wherein thermal migrating of each melt is practiced until the region which is formed thereby extends between, and terminates in, the two major opposed surfaces.
Claim 9
Dependent Claim
30 words
The process of claim 4 wherein thermal migrating of each melt is practiced until the region which is formed thereby extends between, and terminates in, the two major opposed surfaces.
Claim 10
Dependent Claim
70 words
The process of claim 5 and further including the additional process step prior to the disposing at least one metal wire on the surface of forming at least two semiconductor devices in mutually adjacent regions of the body, each device having at least one p-n junction, and wherein the region of recrystallized semiconductor material is disposed between and in abutting contact with each of the at least two semiconductor devices.
Claim 11
Dependent Claim
67 words
The process of claim 2 and further including the additional process step prior to the selected etching of the major surface of forming at least two semiconductor devices in mutually adjacent regions of the body, each device having at least one p-n junction, and wherein the region of recrystallized semiconductor material is disposed between and in abutting contact with each of the at least two semiconductor devices.
Claim 12
Dependent Claim
67 words
The process of claim 4 and further including the additional process step prior to the selected etching of the major surface of forming at least two semiconductor devices in mutually adjacent regions of the body, each device having at least one p-n junction, and wherein the region of recrystallized semiconductor material is disposed between and in abutting contact with each of the at least two semiconductor devices.
Claim 13
Dependent Claim
121 words
The process of claim 1 and including practicing the process steps prior to the disposing at least one metal wire on the surface of masking the body of semiconductor material with at least one material which is of a photoresist type to provide selected exposed surface areas of the body, depositing the at least one metal wire as a layer of metal on the photoresist type masking layer and the selected exposed surface areas of the body, and heating the metal coated body to remove all of the metal layer except for that portion deposited on the selected surfaces of the body by burning off the photoresist type material layer to lift the metal layer disposed thereon away from the body.
Claim 14
Dependent Claim
47 words
The process of claim 1 wherein thermal migrating of each melt is practiced at a temperature slightly above the metal-semiconductor material eutectic temperature in order to minimize the lateral diffusion of the dissolved metal material which imparts the minority carrier lifetime control to the recrystallized semiconductor material.
Claim 15
Dependent Claim
20 words
The process of claim 1 wherein the planar crystal structure orientation is (111), and the first crystal axis is <111>.
Claim 16
Dependent Claim
25 words
The process of claim 14 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 17
Dependent Claim
28 words
The process of claim 15 wherein the preferred stable wire direction is at least one selected from the group consisting of <011>, <101>, <110>, <112>, <211> and <121>.
Claim 18
Dependent Claim
11 words
The process of claim 15 wherein the semiconductor material is silicon.
Claim 19
Dependent Claim
11 words
The process of claim 16 wherein the semiconductor material is silicon.
Claim 20
Dependent Claim
38 words
The process of claim 3 wherein the planar crystal structure orientation is (100), the first crystal axis is <100>, and the preferred stable wire direction is at least one selected from the group consisting of <011> and <011>.
Claim 21
Dependent Claim
25 words
The process of claim 19 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 22
Dependent Claim
11 words
The process of claim 20 wherein the semiconductor material is silicon.
Claim 23
Dependent Claim
27 words
The process of claim 1 wherein the planar crystal structure orientation is (110), the first crystal axis is <110>, and the preferred stable wire direction is <110>.
Claim 24
Dependent Claim
25 words
The process of claim 22 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 25
Dependent Claim
11 words
The process of claim 23 wherein the semiconductor material is silicon.
Claim 26
Dependent Claim
20 words
The process of claim 3 wherein the planar crystal structure orientation is (111) and the first crystal axis is <111>.
Claim 27
Dependent Claim
25 words
The process of claim 25 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 28
Dependent Claim
28 words
The process of claim 26 wherein the preferred stable wire direction is at least one selected from the group consisting of <011>, <101>, <110>, <112>, <211> and <121>.
Claim 29
Dependent Claim
11 words
The process of claim 26 wherein the semiconductor material is silicon.
Claim 30
Dependent Claim
11 words
The process of claim 27 wherein the semiconductor material is silicon.
Claim 31
Dependent Claim
38 words
The process of claim 3 wherein the planar crystal structure orientation is (100), the first crystal axis is <100>, and the preferred stable wire direction is at least one selected from the group consisting of <011> and <011>.
Claim 32
Dependent Claim
25 words
The process of claim 30 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 33
Dependent Claim
11 words
The process of claim 31 wherein the semiconductor material is silicon.
Claim 34
Dependent Claim
27 words
The process of claim 3 wherein the planar crystal structure orientation is (110), the first crystal axis is <110>, and the preferred stable wire direction is <110>.
Claim 35
Dependent Claim
25 words
The process of claim 33 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 36
Dependent Claim
11 words
The process of claim 34 wherein the semiconductor material is silicon.
Claim 37
Dependent Claim
20 words
The process of claim 5 wherein the planar crystal structure orientation is (111), and the first crystal axis is <111>.
Claim 38
Dependent Claim
25 words
The process of claim 36 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 39
Dependent Claim
28 words
The process of claim 37 wherein the preferred stable wire direction is at least one selected from the group consisting of <011>, <101>, <110>, <112>, <211> and <121>.
Claim 40
Dependent Claim
11 words
The process of claim 37 wherein the semiconductor material is silicon.
Claim 41
Dependent Claim
10 words
The process of claim 38 wherein the semiconductor is silicon.
Claim 42
Dependent Claim
38 words
The process of claim 5 wherein the planar crystal structure orientation is (100), the first crystal axis is <100>, and the preferred stable wire direction is at least one selected from the group consisting of <011> and <011>.
Claim 43
Dependent Claim
25 words
The process of claim 41 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 44
Dependent Claim
11 words
The process of claim 42 wherein the semiconductor material is silicon.
Claim 45
Dependent Claim
27 words
The process of claim 5 wherein the planar crystal structure orientation is (110), the first crystal axis is <110>, and the preferred stable wire direction is <110>.
Claim 46
Dependent Claim
25 words
The process of claim 44 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 47
Dependent Claim
11 words
The process of claim 45 wherein the semiconductor material is silicon.
Claim 48
Dependent Claim
20 words
The process of claim 7 wherein the planar crystal structure orientation is (111), and the first crystal axis is <111>.
Claim 49
Dependent Claim
25 words
The process of claim 47 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 50
Dependent Claim
28 words
The process of claim 48 wherein the preferred stable wire direction is at least one selected from the group consisting of <011>, <101>, <110>, <112>, <211> and <121>.
Claim 51
Dependent Claim
11 words
The process of claim 48 wherein the semiconductor material is silicon.
Claim 52
Dependent Claim
11 words
The process of claim 49 wherein the semiconductor material is silicon.
Claim 53
Dependent Claim
38 words
The process of claim 7 wherein the planar crystal structure orientation is (100), the first crystal axis is <100>, and the preferred stable wire direction is at least one selected from the group consisting of <011> and <011>.
Claim 54
Dependent Claim
25 words
The process of claim 52 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 55
Dependent Claim
11 words
The process of claim 53 wherein the semiconductor material is silicon.
Claim 56
Dependent Claim
27 words
The process of claim 7 wherein the planar crystal structure orientation is (110), the first crystal axis is <110>, and the preferred stable wire direction is <110>.
Claim 57
Dependent Claim
25 words
The process of claim 55 wherein the metal wire comprises at least one metal selected from the group consisting of gold, silicon, platinum and copper.
Claim 58
Dependent Claim
11 words
The process of claim 56 wherein the semiconductor material is silicon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |