US3982967A
Expired / Lapsed
US
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Method of proton-enhanced diffusion for simultaneously forming integrated circuit regions of varying depths
Assignee: International Business Machines Corp
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Filing: 1975-03-26
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Granted: 1976-09-28
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Expires: 1995-03-26
Abstract
Abstract In integrated circuit fabrication, a method is provided for simultaneously forming two regions of the same conductivity-type such as the base and isolation regions. In one embodiment, an epitaxial layer of one conductivity-type is formed on a substrate of opposite conductivity-type, after which dopant ions of the opposite conductivity-type are introduced into the epitaxial surface areas which are to provide the base and isolation regions, and in addition, the isolation regions are bombarded with non-dopant ions having a maximum atomic number of two, e.g., hydrogen or helium ion while the base regions are appropriately masked and remain umbombarded, said bombardment is carried out at temperatures below 300° C, preferably room temperature. The bombardment is preferably carried out so that the non-dopant ions are implanted primarily in regions below the isolation regions. Next, the wafer is heated at a temperature at a range of from 600° - 900° C which is substantially below normal drive-in diffusion temperatures for unbombarded doped regions. The heating to be maintained for a period sufficient to drive-in diffuse the bombarded isolation regions through the epitaxial layer into contact with the substrate but is insufficient to drive-in the unbombarded base regions to such a depth.
Inventors
- 👤 San-Mei Ku
- 👤 Charles A. Pillus
- 👤 Michael R. Poponiak
- 👤 Robert O. Schwenker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:22
CPC Classifications
H; H10; H10P; H10P34/00; H10P34/40; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10P30/208; H10P30/21; H10P30/28
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
90 words
A method for forming regions of a selected conductivity-type in a semiconductor substrate comprising introducing dopant ions of said conductivity-type into selected regions of a surface of said substrate, and additionally bombarding at least portions of said regions with non-dopant ions having a maximum atomic number of 2, said bombardment being carried out at a temperature below 300° C, and heating said substrate at a temperature in the range of from 600° to 900° C sufficient to diffuse dopant ions from said regions further into said substrate and to anneal.
Claim 2
Independent Claim
90 words
A method for forming regions of a selected conductivity-type in a semiconductor substrate comprising introducing dopant ions of said conductivity-type into selected regions of a surface of said substrate, and additionally bombarding at least portions of said regions with non-dopant ions having a maximum atomic number of 2, said bombardment being carried out at a temperature below 300° C, and heating said substrate at a temperature in the range of from 600° to 900° C sufficient to diffuse dopant ions from said regions further into said substrate and to anneal.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said dopant ions are introduced by diffusion.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said dopant ions are introduced by ion implantation.
Claim 5
Dependent Claim
14 words
The method of claim 2 wherein said diffusion of dopant ions precedes said bombardment.
Claim 6
Dependent Claim
15 words
The method of claim 3 wherein said ion implantation of dopant ions precedes said bombardment.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein said non-dopant ions are protons.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein said non-dopant ions are helium ions.
Claim 9
Dependent Claim
11 words
The method of claim 1 wherein said semiconductor substrate is silicon.
Claim 10
Dependent Claim
38 words
The method of claim 1 wherein said bombardment with non-dopant ions is carried out at an energy sufficient to introduce the non-dopant ions at a depth from said surface beyond the depth of said regions of dopant ions.
Claim 11
Independent Claim
84 words
A method for forming regions of a selected conductivity in a semiconductor substrate comprising introducing dopant ions into selected regions of said substrate, and additionally bombarding at least portions of said regions with non-dopant ions having a maximum atomic number of 2, said bombardment being carried out at a temperature below 300° C, and heating said substrate at a temperature in the range of from 600° to 900° C sufficient to diffuse dopant ions from said regions further into said substrate and to anneal.
Claim 12
Independent Claim
84 words
A method for forming regions of a selected conductivity in a semiconductor substrate comprising introducing dopant ions into selected regions of said substrate, and additionally bombarding at least portions of said regions with non-dopant ions having a maximum atomic number of 2, said bombardment being carried out at a temperature below 300° C, and heating said substrate at a temperature in the range of from 600° to 900° C sufficient to diffuse dopant ions from said regions further into said substrate and to anneal.
Claim 13
Dependent Claim
32 words
The method of claim 10 wherein said bombardment with non-dopant ions is carried out at an energy sufficient to introduce the non-dopant ions into substrate regions adjacent to said selected conductivity regions.
Claim 14
Independent Claim
117 words
A method for forming regions of a selected conductivity-type extending to different depths in a semiconductor substrate comprising simultaneously introducing dopant ions of said conductivity-type into a plurality of regions of a surface of said substrate, and additionally bombarding at a temperature below 300° C at least portions of each of the regions in a first set of said conductivity-type regions with non-dopant ions having a maximum atomic number of 2 while permitting a second set of said regions to remain unbombarded, and heating said substrate at a temperature in the range of from 600° to 900° C sufficient to selectively drive-in diffuse said bombarded regions to a greater depth from said surface than said unbombarded regions.
Claim 15
Independent Claim
117 words
A method for forming regions of a selected conductivity-type extending to different depths in a semiconductor substrate comprising simultaneously introducing dopant ions of said conductivity-type into a plurality of regions of a surface of said substrate, and additionally bombarding at a temperature below 300° C at least portions of each of the regions in a first set of said conductivity-type regions with non-dopant ions having a maximum atomic number of 2 while permitting a second set of said regions to remain unbombarded, and heating said substrate at a temperature in the range of from 600° to 900° C sufficient to selectively drive-in diffuse said bombarded regions to a greater depth from said surface than said unbombarded regions.
Claim 16
Dependent Claim
38 words
The method of claim 12 wherein said bombardment with non-dopant ions is carried out at an energy sufficient to introduce the non-dopant ions at a depth from said surface beyond the depth of said regions of dopant ions.
Claim 17
Dependent Claim
13 words
The method of claim 13 wherein said dopant ions are introduced by diffusion.
Claim 18
Dependent Claim
14 words
The method of claim 13 wherein said dopant ions are introduced by ion implantation.
Claim 19
Dependent Claim
14 words
The method of claim 14 wherein said diffusion of dopant ions precedes said bombardment.
Claim 20
Dependent Claim
15 words
The method of claim 15 wherein said ion implantation of dopant ions precedes said bombardment.
Claim 21
Dependent Claim
11 words
The method of claim 13 wherein said non-dopant ions are protons.
Claim 22
Dependent Claim
12 words
The method of claim 13 wherein said non-dopant ions are helium ions.
Claim 23
Dependent Claim
11 words
The method of claim 13 wherein said semiconductor substrate is silicon.
Claim 24
Independent Claim
134 words
A method for simultaneously forming the base and isolation regions in junction isolated planar transistor integrated circuits comprising forming an epitaxial layer of one conductivity-type on a semiconductor substrate of opposite conductivity-type, simultaneously introducing dopant ions of said opposite conductivity-type into the epitaxial surface regions selected for said base and isolation regions, and additionally bombarding at a temperature below 300° C at least portions of said isolation regions with non-dopant ions having a maximum atomic number of 2 while permitting said base regions to remain unbombarded, and heating said epitaxial layer at temperatures in the range of from 600° to 900° C for a period sufficient to drive-in diffuse said bombarded isolation regions through the epitaxial layer into contact with said substrate but insufficient to drive-in the unbombarded base regions to such a depth.
Claim 25
Independent Claim
134 words
A method for simultaneously forming the base and isolation regions in junction isolated planar transistor integrated circuits comprising forming an epitaxial layer of one conductivity-type on a semiconductor substrate of opposite conductivity-type, simultaneously introducing dopant ions of said opposite conductivity-type into the epitaxial surface regions selected for said base and isolation regions, and additionally bombarding at a temperature below 300° C at least portions of said isolation regions with non-dopant ions having a maximum atomic number of 2 while permitting said base regions to remain unbombarded, and heating said epitaxial layer at temperatures in the range of from 600° to 900° C for a period sufficient to drive-in diffuse said bombarded isolation regions through the epitaxial layer into contact with said substrate but insufficient to drive-in the unbombarded base regions to such a depth.
Claim 26
Dependent Claim
13 words
The method of claim 21 wherein said dopant ions are introduced by diffusion.
Claim 27
Dependent Claim
14 words
The method of claim 21 wherein said dopant ions are introduced by ion implantation.
Claim 28
Dependent Claim
14 words
The method of claim 22 wherein said diffusion of dopant ions precedes said bombardment.
Claim 29
Dependent Claim
15 words
The method of claim 23 wherein said ion implantation of dopant ions precedes said bombardment.
Claim 30
Dependent Claim
11 words
The method of claim 21 wherein said non-dopant ions are protons.
Claim 31
Dependent Claim
12 words
The method of claim 21 wherein said non-dopant ions are helium ions.
Claim 32
Dependent Claim
11 words
The method of claim 21 wherein said semiconductor substrate is silicon.
Claim 33
Dependent Claim
11 words
The method of claim 28 wherein said opposite conductivity-type is P-type.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-28 | 1980-03-29 | 1980-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-28 | 1984-03-29 | 1984-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-28 | 1988-03-29 | 1988-09-28 | $7700.00 | Window Closed / Lapsed |