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US5155369A
Expired / Lapsed
US
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Multiple angle implants for shallow implant
Assignee: Applied Materials Inc
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Filing: 1990-09-28
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Granted: 1992-10-13
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Expires: 2010-09-28
Abstract
Abstract An implantation process in which a first dose of ions is implanted to produce a damaged layer through which a second dose of implant ions is directed. The damaged layer scatters the ions in the second dose so that these latter ions need not be directed at an angle to avoid channeling. The second dose is generally significantly higher than the first so that the resulting doping profile is produced primarily by the second dose, which can be directed perpendicular to the surface of the wafer.
Inventors
- 👤 Michael Current
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:40
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H01; H01J; H01J37/00; H01J37/30; H01J37/317; H01J37/3171; H10P; H10P30/00; H10P30/20; H10P30/222
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
124 words
A method of ion implantation comprising the steps of: (a) implanting a dopant ion into a substrate along a direction D forming an oblique angle A with respect to a perpendicular direction N to a top surface of the substrate to produce at least one damaged region that is sufficiently damaged that a subsequent implant of ions will experience only negligible channeling, wherein the angle A is selected such that these ions do not exhibit a significant amount of channeling; and, after step (a) (b) implanting a dopant ion into at least one of said damaged regions of the substrate along a direction substantially parallel to the direction N, whereby substanially symmetric implanted regions that are substantially free of channeling effects can be produced.
Claim 2
Independent Claim
124 words
A method of ion implantation comprising the steps of: (a) implanting a dopant ion into a substrate along a direction D forming an oblique angle A with respect to a perpendicular direction N to a top surface of the substrate to produce at least one damaged region that is sufficiently damaged that a subsequent implant of ions will experience only negligible channeling, wherein the angle A is selected such that these ions do not exhibit a significant amount of channeling; and, after step (a) (b) implanting a dopant ion into at least one of said damaged regions of the substrate along a direction substantially parallel to the direction N, whereby substanially symmetric implanted regions that are substantially free of channeling effects can be produced.
Claim 3
Dependent Claim
43 words
A method as in claim 1 wherein the concentration of dopant ions produced by step (b) is much greater than the dopant concentration produced by step (a), whereby a resulting dopant concentration distribution is substantially symmetric with respect to the perpendicular direction N.
Claim 4
Dependent Claim
18 words
A method as in claim 1 wherein the same dopant ion is utilized in steps (a) and (b).
Claim 5
Dependent Claim
22 words
A method as in claim 1 wherein a heavier dopant ion is utilized in step (a) than is utilized in step (b).
Claim 6
Dependent Claim
24 words
A method as in claim 1 wherein the dopant ions in step (a) each has a mass of at least 17 atomic mass units.
Claim 7
Dependent Claim
40 words
A method as in claim 1 wherein the implantation ions in step (a) are implanted to a greater implantation depth than in step (b), whereby the dopant ions implanted in step (b) are scattered throughout their trajectory into the substrate.
Claim 8
Dependent Claim
23 words
A method as in claim 6 wherein the ions implanted in step (a) are implanted to a depth in the range 0.1-0.2 microns.
Claim 9
Dependent Claim
18 words
A method as in claim 1 wherein the dopant ions in step (a) produce a surface damage layer.
Claim 10
Dependent Claim
22 words
A method as in claim 8 wherein the ions in step (a) are implanted to a depth in the range 100-300 Angstroms.
Claim 11
Dependent Claim
67 words
A method as in claim 8 wherein a choice of dopant ion and implantation energy in step (a) is selected from the set consisting of: (i) boron at an implant energy less than 10 keV; (ii) BF 2 at an implant energy less than 50 keV; (iii) arsenic at an implant energy less than 20 keV; and (iv) phosphorous at an implant energy less than 15 keV.
Claim 12
Dependent Claim
19 words
A method as in claim 1 wherein, in step (a), angle A is in the range of 5-10 degrees.
Claim 13
Dependent Claim
17 words
A method as in claim 1 wherein said damaged region is sufficiently damaged that it is amorphous.
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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) | 1995-10-13 | 1996-04-13 | 1996-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-13 | 2004-04-13 | 2004-10-13 | $7700.00 | Window Closed / Lapsed |