US5324684A
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US
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Gas phase doping of semiconductor material in a cold-wall radiantly heated reactor under reduced pressure
Assignee: A G ASSOCIATES
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Filing: 1992-02-25
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Granted: 1994-06-28
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Expires: 2012-02-25
Abstract
Abstract A technique for doping silicon material or other semiconductors uses gas phase dopant sources under reduced pressure in a radiantly heated, cold-wall reactor. The technique is applied to the automated integrated circuit manufacturing techniques being adopted in modern fabrication facilities. The method includes placing a substrate comprising semiconductor material on a thermally isolated support structure in a reduced pressure, cold-wall reaction chamber; radiantly heating the substrate within the reaction chamber to a controlled temperature; flowing a gas phase source of dopant at controlled pressure and concentration in contact with the substrate so that the dopant is absorbed by the substrate, and annealing the substrate. The substrate may be first coated with a layer of polycrystalline semiconductor, and then gas phase doping as described above may be applied to the polycrystalline layer.
Inventors
- 👤 Ahmad Kermani
- 👤 Kristian E. Johnsgard
- 👤 Carl Galewski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:35
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/015; H10P; H10P72/00; H10P72/04; H10P72/0451; H10P72/0452; H10P72/0454; H10D62/00; H10D62/40; H10D62/405; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/17; H10P32/171; H10P32/30; H10P32/302; H10P72/0468; Y; Y10; Y10S; Y10S148/00; Y10S148/03; Y10S148/035; Y10S438/00; Y10S438/914; Y10S438/923
Claims Analysis
Total Claims: 83
Claim 1
Independent Claim
79 words
A method for forming doped semiconductor, comprising: placing a substrate comprising semiconductor material in a radiantly heated, reduced pressure reaction chamber; radiantly heating the substrate within the reaction chamber to a controlled temperature; flowing a gas phase source of dopant at controlled pressure and concentration in contact with the substrate so that the dopant is absorbed by the substrate to a selected depth in the substrate; and annealing the substrate to further diffuse the dopant in a controlled manner.
Claim 2
Independent Claim
79 words
A method for forming doped semiconductor, comprising: placing a substrate comprising semiconductor material in a radiantly heated, reduced pressure reaction chamber; radiantly heating the substrate within the reaction chamber to a controlled temperature; flowing a gas phase source of dopant at controlled pressure and concentration in contact with the substrate so that the dopant is absorbed by the substrate to a selected depth in the substrate; and annealing the substrate to further diffuse the dopant in a controlled manner.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein the semiconductor material comprises silicon.
Claim 4
Dependent Claim
18 words
The method of claim 2, wherein the source of dopant comprises a Group III or Group V element.
Claim 5
Dependent Claim
19 words
The method of claim 1, wherein the source of dopant comprises a dopant hydride with a carrier comprising hydrogen.
Claim 6
Dependent Claim
21 words
The method of claim 1, wherein the source of dopant comprises a dopant hydride with a carrier comprising an inert gas.
Claim 7
Dependent Claim
26 words
The method of claim 1, wherein the source of dopant comprises a dopant hydride with a carrier comprising a mixture of hydrogen and an inert gas.
Claim 8
Dependent Claim
46 words
The method of claim 1, wherein substrate has a reaction surface and the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the reaction chamber, the gas flow path proceeding essentially perpendicular to the reaction surface of the substrate.
Claim 9
Dependent Claim
54 words
The method of claim 1, wherein substrate has a reaction surface and the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the reaction chamber, the gas flow path proceeding essentially perpendicular to the reaction surface of the substrate, and radially symmetrically off of the reaction surface.
Claim 10
Dependent Claim
73 words
The method of claim 1, wherein substrate has a reaction surface facing a source of radiant energy and the step of flowing a gas phase source of dopant includes: supplying the source of dopant to the reaction chamber between the source of radiant energy and the reaction surface; pumping the source of dopant from the reaction chamber at a position establishing a single pass of the source of dopant over the reaction surface.
Claim 11
Dependent Claim
24 words
The method of claim 9, wherein the single pass proceeds essentially perpendicular to the reaction surface and radially symmetrically off of the reaction surface.
Claim 12
Dependent Claim
21 words
The method of claim 1, wherein the reaction chamber has walls, and further including: cooling the walls of the reaction chamber.
Claim 13
Dependent Claim
26 words
The method of claim 1, wherein the step of placing the substrate within a reaction chamber includes: supporting the substrate with a thermally inert support structure.
Claim 14
Dependent Claim
44 words
The method of claim 1, further including prior to the step of flowing a source of dopant: cleaning oxide from the substrate so that regions to be doped have a concentration of oxide at reaction surfaces of less than 2×10 14 /cm 2 .
Claim 15
Independent Claim
93 words
A method for forming doped semiconductor, comprising: forming a layer of polycrystalline semiconductor on a reaction surface of a substrate; radiantly heating the layer on the reaction surface of the substrate within a reaction chamber to a controlled temperature; flowing a gas phase source of dopant at controlled pressure and concentration in contact with the layer so that the dopant is absorbed in the layer to a selected depth in the layer; and annealing the substrate to activate and further diffuse the dopant in a controlled manner within the layer of polycrystalline semiconductor.
Claim 16
Independent Claim
93 words
A method for forming doped semiconductor, comprising: forming a layer of polycrystalline semiconductor on a reaction surface of a substrate; radiantly heating the layer on the reaction surface of the substrate within a reaction chamber to a controlled temperature; flowing a gas phase source of dopant at controlled pressure and concentration in contact with the layer so that the dopant is absorbed in the layer to a selected depth in the layer; and annealing the substrate to activate and further diffuse the dopant in a controlled manner within the layer of polycrystalline semiconductor.
Claim 17
Dependent Claim
26 words
The method of claim 14, further including a second step of annealing the substrate to drive dopant into the substrate from the layer of polycrystalline semiconductor.
Claim 18
Dependent Claim
11 words
The method of claim 14, wherein the polycrystalline semiconductor comprises silicon.
Claim 19
Dependent Claim
18 words
The method of claim 16, wherein the source of dopant comprises a Group III or Group V element.
Claim 20
Dependent Claim
19 words
The method of claim 14, wherein the source of dopant comprises a dopant hydride with a carrier comprising hydrogen.
Claim 21
Dependent Claim
21 words
The method of claim 14, wherein the source of dopant comprises a dopant hydride with a carrier comprising an inert gas.
Claim 22
Dependent Claim
26 words
The method of claim 14, wherein the source of dopant comprises a dopant hydride with a carrier comprising a mixture of hydrogen and an inert gas.
Claim 23
Dependent Claim
40 words
The method of claim 14, wherein the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the reaction chamber, the gas flow path proceeding essentially perpendicular to the reaction surface of the substrate.
Claim 24
Dependent Claim
48 words
The method of claim 14, wherein the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the reaction chamber, the gas flow path proceeding essentially perpendicular to the reaction surface of the substrate, and radially symmetrically off of the reaction surface.
Claim 25
Dependent Claim
81 words
The method of claim 14, further including: supporting the substrate within the reaction chamber so that the reaction surface faces a source of radiant energy; and the step of flowing a gas phase source of dopant includes: supplying the source of dopant to the reaction chamber between the source of radiant energy and the reaction surface; pumping the source of dopant from the reaction chamber at a position establishing a single pass of the source of dopant over the reaction surface.
Claim 26
Dependent Claim
24 words
The method of claim 23, wherein the single pass proceeds essentially perpendicular to the reaction surface and radially symmetrically off of the reaction surface.
Claim 27
Dependent Claim
21 words
The method of claim 14, wherein the reaction chamber has walls, and further including: cooling the walls of the reaction chamber.
Claim 28
Dependent Claim
27 words
The method of claim 14, further including: supporting the substrate with a thermally inert support structure in the reaction chamber during the steps of heating and flowing.
Claim 29
Dependent Claim
42 words
The method of claim 14, further including prior to the step of flowing a source of dopant: cleaning oxide from the polycrystalline semiconductor so that regions to be doped have a concentration of oxide of less than 2×10 14 /cm 2 .
Claim 30
Independent Claim
126 words
A method for forming doped semiconductor, comprising: forming, in a first controlled pressure reaction chamber, a layer of polycrystalline semiconductor on a reaction surface of a substrate; transferring the substrate with the polycrystalline semiconductor layer, to a second controlled pressure reaction chamber without exposing the substrate to air; radiantly heating the layer on the reaction surface of substrate within the second reaction chamber to a controlled temperature; flowing, in the second reaction chamber, a gas phase source of dopant at controlled pressure and concentration in contact with the layer so that the dopant is absorbed in the layer to a selected depth in the layer; and annealing the substrate to activate and further diffuse the dopant in a controlled manner within the layer of polycrystalline semiconductor.
Claim 31
Independent Claim
126 words
A method for forming doped semiconductor, comprising: forming, in a first controlled pressure reaction chamber, a layer of polycrystalline semiconductor on a reaction surface of a substrate; transferring the substrate with the polycrystalline semiconductor layer, to a second controlled pressure reaction chamber without exposing the substrate to air; radiantly heating the layer on the reaction surface of substrate within the second reaction chamber to a controlled temperature; flowing, in the second reaction chamber, a gas phase source of dopant at controlled pressure and concentration in contact with the layer so that the dopant is absorbed in the layer to a selected depth in the layer; and annealing the substrate to activate and further diffuse the dopant in a controlled manner within the layer of polycrystalline semiconductor.
Claim 32
Dependent Claim
26 words
The method of claim 28, further including a second step of annealing the substrate to drive dopant into the substrate from the layer of polycrystalline semiconductor.
Claim 33
Dependent Claim
11 words
The method of claim 28, wherein the polycrystalline semiconductor comprises silicon.
Claim 34
Dependent Claim
18 words
The method of claim 30, wherein the source of dopant comprises a Group III or Group V element.
Claim 35
Dependent Claim
19 words
The method of claim 28, wherein the source of dopant comprises a dopant hydride with a carrier comprising hydrogen.
Claim 36
Dependent Claim
21 words
The method of claim 28, wherein the source of dopant comprises a dopant hydride with a carrier comprising an inert gas.
Claim 37
Dependent Claim
26 words
The method of claim 28, wherein the source of dopant comprises a dopant hydride with a carrier comprising a mixture of hydrogen and an inert gas.
Claim 38
Dependent Claim
41 words
The method of claim 28, wherein the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the second reaction chamber, the gas flow path proceeding essentially perpendicular to the reaction surface of the substrate.
Claim 39
Dependent Claim
49 words
The method of claim 28, wherein the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the second reaction chamber, the gas flow path proceeding essentially perpendicular to the reaction surface of the substrate, and radially symmetrically off of the reaction surface.
Claim 40
Dependent Claim
84 words
The method of claim 28, further including: supporting the substrate within the second reaction chamber so that the reaction surface faces a source of radiant energy; and the step of flowing a gas phase source of dopant includes: supplying the source of dopant to the second reaction chamber between the source of radiant energy and the reaction surface; pumping the source of dopant from the second reaction chamber at a position establishing a single pass of the source of dopant over the reaction surface.
Claim 41
Dependent Claim
24 words
The method of claim 37, wherein the single pass proceeds essentially perpendicular to the reaction surface and radially symmetrically off of the reaction surface.
Claim 42
Dependent Claim
23 words
The method of claim 28, wherein the second reaction chamber has walls, and further including: cooling the walls of the second reaction chamber.
Claim 43
Dependent Claim
28 words
The method of claim 28, further including: supporting the substrate with a thermally inert support structure in the second reaction chamber during the steps of heating and flowing.
Claim 44
Dependent Claim
31 words
The method of claim 28, wherein the step of transferring comprises: robotically transporting the substrate from the first reaction chamber to the second reaction chamber through a controlled atmosphere transfer region.
Claim 45
Independent Claim
113 words
A method for forming doped semiconductor, comprising: placing a substrate comprising a semiconductor material in a radiantly heated, controlled pressure reaction chamber; masking the substrate to form a pattern on the substrate, the pattern exposing a contact region on the substrate; heating the substrate within the reaction chamber to a controlled temperature; flowing a gas source of dopant at a controlled pressure and concentration in contact with the substrate and the contact region so that the dopant is absorbed by the substrate and the contact region to a desired depth in the substrate and in the contact region; and annealing the substrate to further diffuse the dopant to a controlled concentration and depth.
Claim 46
Independent Claim
113 words
A method for forming doped semiconductor, comprising: placing a substrate comprising a semiconductor material in a radiantly heated, controlled pressure reaction chamber; masking the substrate to form a pattern on the substrate, the pattern exposing a contact region on the substrate; heating the substrate within the reaction chamber to a controlled temperature; flowing a gas source of dopant at a controlled pressure and concentration in contact with the substrate and the contact region so that the dopant is absorbed by the substrate and the contact region to a desired depth in the substrate and in the contact region; and annealing the substrate to further diffuse the dopant to a controlled concentration and depth.
Claim 47
Dependent Claim
23 words
The method according to claim 42, wherein the substrate comprises a nonplanar feature and the contact region is located within the nonplanar region.
Claim 48
Dependent Claim
13 words
The method according to claim 43, wherein the nonplanar feature comprises a trench.
Claim 49
Dependent Claim
10 words
The method of claim 42, wherein the substrate comprises silicon.
Claim 50
Dependent Claim
19 words
The method according to claim 45, wherein the source of dopant comprises a Group III or Group V element.
Claim 51
Dependent Claim
20 words
The method according to claim 42, wherein the source of dopant comprises a dopant hydride with a carrier comprising hydrogen.
Claim 52
Dependent Claim
22 words
The method according to claim 42, wherein the source of dopant comprises a dopant hydride with a carrier comprising an inert gas.
Claim 53
Dependent Claim
25 words
The method according to claim 42, wherein the dopant comprises a dopant hydride with a carrier comprising a mixture of hydrogen and an inert gas.
Claim 54
Dependent Claim
47 words
The method according to claim 42, wherein the substrate has a reaction surface and the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the reaction chamber, the gas flow proceeding essentially perpendicular to the reaction surface of the substrate.
Claim 55
Dependent Claim
56 words
The method according to claim 42, wherein the substrate has a reaction surface and the step of flowing a gas phase source of dopant includes: establishing a gas flow path in the reaction chamber, the gas flow path proceeding essentially perpendicularly to the reaction surface of the substrate and radially symmetric off of the reaction substrate.
Claim 56
Dependent Claim
73 words
The method according to claim 42, wherein the substrate has a reaction surface facing a source of radiant energy and the step of flowing a gas phase source of dopant includes: supplying the source of dopant to the reaction chamber between the source of radiant energy and the reaction surface; and pumping the source of dopant from the reaction chamber at a position establishing a single pass of dopant over the reaction surface.
Claim 57
Dependent Claim
25 words
The method according to claim 52, wherein the single pass proceeds essentially perpendicular to the reaction surface and radially symmetric off of the reaction surface.
Claim 58
Dependent Claim
22 words
The method according to claim 42, wherein the reaction chamber has walls and further including: cooling the walls of the reaction chamber.
Claim 59
Dependent Claim
27 words
The method according to claim 42, wherein the step of placing the substrate within a reaction chamber includes: supporting the substrate with a thermally inert support structure.
Claim 60
Dependent Claim
43 words
The method according to claim 42, further comprising prior to the step of flowing a gas phase source of dopant: cleaning oxide from the substrate so that regions to be doped have a concentration of oxide less than 2×10 14 /cm 2 .
Claim 61
Dependent Claim
26 words
The method according to claim 42, further including a second step of annealing the substrate to drive the dopant into the substrate from the contact region.
Claim 62
Dependent Claim
13 words
The method according to claim 42, wherein the substrate comprises a polycrystalline semiconductor.
Claim 63
Dependent Claim
12 words
The method according to claim 58, wherein the polycrystalline semiconductor comprises silicon.
Claim 64
Dependent Claim
26 words
The method according to claim 1, wherein the substrate comprises a nonplanar feature and a contact region, the contact region being located within the nonplanar feature.
Claim 65
Dependent Claim
13 words
The method according to claim 60, wherein the nonplanar feature comprises a trench.
Claim 66
Dependent Claim
26 words
The method according to claim 14, wherein the substrate comprises a nonplanar feature and a contact region, the contact region being located within the nonplanar feature.
Claim 67
Dependent Claim
13 words
The method according to claim 62, wherein the nonplanar feature comprises a trench.
Claim 68
Dependent Claim
26 words
The method according to claim 28, wherein the substrate comprises a nonplanar feature and a contact region, the contact region being located within the nonplanar feature.
Claim 69
Dependent Claim
13 words
The method according to claim 64, wherein the nonplanar feature comprises a trench.
Claim 70
Dependent Claim
20 words
The method according to claim 1, wherein the heating is carried out at about 1000° C. for about 1 minute.
Claim 71
Dependent Claim
20 words
The method according to claim 66, wherein the annealing is carried out at about 1000° C. for about 30 seconds.
Claim 72
Dependent Claim
20 words
The method according to claim 14, wherein the heating is carried out at about 1000° C. for about 1 minute.
Claim 73
Dependent Claim
20 words
The method according to claim 68, wherein the annealing is carried out at about 1000° C. for about 30 seconds.
Claim 74
Dependent Claim
20 words
The method according to claim 28, wherein the heating is carried out at about 1000° C. for about 1 minute.
Claim 75
Dependent Claim
20 words
The method according to claim 70, wherein the annealing is carried out at about 1000° C. for about 30 seconds.
Claim 76
Dependent Claim
20 words
The method according to claim 42, wherein the heating is carried out at about 1000° C. for about 1 minute.
Claim 77
Dependent Claim
20 words
The method according to claim 70, wherein the annealing is carried out at about 1000° C. for about 30 seconds.
Claim 78
Independent Claim
133 words
A method for fabricating shallow junctions for contact regions for integrated circuit devices, comprising: forming a layer of polycrystalline semiconductor on a surface of a substrate; placing the substrate in a radiantly heated, reduced pressure reaction chamber; radiantly heating the substrate within the reaction chamber to a first controlled temperature; flowing for a controlled time a gas phase source of dopant at a controlled pressure and concentration in contact with the polycrystalline semiconductor so that dopant is absorbed by the polycrystalline semiconductor; annealing at a second controlled temperature to diffuse the dopant in a controlled manner into the polycrystalline semiconductor; and annealing further under conditions such that the dopant in the polycrystalline semiconductor diffuses in a controlled manner into the substrate to create junctions having a controlled shallow depth and controlled dopant concentration.
Claim 79
Independent Claim
133 words
A method for fabricating shallow junctions for contact regions for integrated circuit devices, comprising: forming a layer of polycrystalline semiconductor on a surface of a substrate; placing the substrate in a radiantly heated, reduced pressure reaction chamber; radiantly heating the substrate within the reaction chamber to a first controlled temperature; flowing for a controlled time a gas phase source of dopant at a controlled pressure and concentration in contact with the polycrystalline semiconductor so that dopant is absorbed by the polycrystalline semiconductor; annealing at a second controlled temperature to diffuse the dopant in a controlled manner into the polycrystalline semiconductor; and annealing further under conditions such that the dopant in the polycrystalline semiconductor diffuses in a controlled manner into the substrate to create junctions having a controlled shallow depth and controlled dopant concentration.
Claim 80
Dependent Claim
12 words
A method according to claim 74, wherein the polycrystalline semiconductor comprises silicon.
Claim 81
Dependent Claim
15 words
A method according to claim 74, wherein the first controlled temperature is about 1000° C.
Claim 82
Dependent Claim
15 words
A method according to claim 74, wherein the second controlled temperature is about 1000° C.
Claim 83
Dependent Claim
17 words
A method according to claim 77, wherein the second controlled temperature is held for about 30 seconds.
References Cited (Backward Citations)
US3524776A
Cited
US3949119A
Cited
US4124417A
Cited
US4108106A
Cited
US4939103A
Cited
US4766678A
Cited
US4951601A
Cited
JPS63239939A
Cited
US5156820A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |