US5795801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
MethodS of fabricating profiled device wells for improved device isolation
Assignee: Samsung Electronics Co Ltd
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Filing: 1996-08-09
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Granted: 1998-08-18
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Expires: 2016-08-09
Abstract
Abstract A trench is formed in a substrate, the trench defining an active region surface on the substrate, the trench having a trench sidewall. A trench insulation region is then formed in the trench. The substrate underlying the trench sidewall is doped with impurities, and after the first doping, the substrate underlying the active region surface is doped with impurities to form a well having an impurity concentration which increases towards the trench sidewall in a predetermined manner. To form the trench, an insulation layer preferably is formed on the substrate, a barrier layer is formed on the insulation layer, and the barrier layer and the insulation layer are patterned to form an insulation region on the substrate and a barrier region on the insulation region. The substrate is then etched using the barrier region and the insulation region as a mask to thereby form a trench in the substrate. Preferably, the first doping includes implanting ions into the substrate through the trench insulation region and the trench sidewall using the barrier region as a mask. The second doping preferably is preceded by removal of the barrier region, and includes implanting ions into the substrate through the active region surface. The first implantation preferably occurs at a predetermined angle of incidence oblique to the active region surface or, more preferably, over a predetermined range of angles of incidence. The first and second doping steps may include doping with impurities of the same conductivity type or with opposite conductivity types.
Inventors
- 👤 Kang-yoon Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:00
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0145; H10W10/0148; H10W10/041; H10W10/10; H10W10/17; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/085; Y10S148/086
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
111 words
A method of forming an isolated well in a substrate, the method comprising the steps of: forming a trench in the substrate, the trench defining an active region surface on the substrate adjacent the trench, the trench having a trench sidewall adjacent the active region surface; forming a trench insulation region in the trench; first doping the substrate underlying the trench sidewall with impurities; and after said first doping step, second doping the substrate underlying the active region surface with impurities to thereby form a well in the substrate underlying the active region surface and adjacent the trench sidewall, the well having an impurity concentration which increases towards the trench sidewall.
Claim 2
Independent Claim
111 words
A method of forming an isolated well in a substrate, the method comprising the steps of: forming a trench in the substrate, the trench defining an active region surface on the substrate adjacent the trench, the trench having a trench sidewall adjacent the active region surface; forming a trench insulation region in the trench; first doping the substrate underlying the trench sidewall with impurities; and after said first doping step, second doping the substrate underlying the active region surface with impurities to thereby form a well in the substrate underlying the active region surface and adjacent the trench sidewall, the well having an impurity concentration which increases towards the trench sidewall.
Claim 3
Dependent Claim
101 words
A method according to claim 1 wherein said step of forming a trench comprises the steps of: forming an insulation layer on the substrate; forming a barrier layer on the insulation layer; patterning the barrier layer and the insulation layer to form an insulation region on the substrate and a barrier region on the insulation region; and etching the substrate using the barrier region and the insulation region as a mask to thereby form a trench in the substrate, the trench defining an active region surface on the substrate, the active region surface underlying the insulation region and the barrier region.
Claim 4
Dependent Claim
53 words
A method according to claim 2 wherein said step of forming a trench insulation region comprises the steps of: forming a second insulation layer on the substrate, covering the barrier region; and removing portions of the second insulation layer to expose the barrier region and leave a trench insulation region in the trench.
Claim 5
Dependent Claim
81 words
A method according to claim 3 wherein said step of removing comprises the steps of: planarizing the second insulation layer to expose the barrier region and leave a portion of the second insulation layer in the trench; and anisotropically etching the portion of the second insulation layer in the trench adjacent the barrier region to expose a sidewall portion of the barrier region and leave a trench insulation region in the trench, the trench insulation region extending above the trench sidewall.
Claim 6
Dependent Claim
52 words
A method according to claim 4, further comprising the steps of: removing the insulation region overlying the active region surface to thereby expose the active region surface; forming a second insulation region on the active region surface; and forming a semiconductor region on the second insulation region on the active region surface.
Claim 7
Dependent Claim
71 words
A method according to claim 3: wherein said first doping step comprises the step of implanting ions into the substrate through the trench insulation region and the trench sidewall using the barrier region as a mask; wherein said second doping step is preceded by the step of removing the barrier region; and wherein said second doping step comprises the step of implanting ions into the substrate through the active region surface.
Claim 8
Dependent Claim
32 words
A method according to claim 6 wherein said first step of implanting ions comprises the step of implanting ions into the substrate at angle of incidence oblique to the active region surface.
Claim 9
Dependent Claim
34 words
A method according to claim 6 wherein said first step of implanting ions comprises the step of implanting ions into the substrate over range of angles of incidence oblique to the active region surface.
Claim 10
Dependent Claim
52 words
A method according to claim 1: wherein said first doping step comprises the step of doping the substrate underlying the trench sidewall with impurities of first conductivity type; and wherein said second doping step comprises the step of doping the substrate underlying the active region surface with impurities of second conductivity type.
Claim 11
Dependent Claim
52 words
A method according to claim 1: wherein said first doping step comprises the step of doping the substrate underlying the trench sidewall with impurities of first conductivity type; and wherein said second doping step comprises the step of doping the substrate underlying the active region surface with impurities of first conductivity type.
Claim 12
Independent Claim
213 words
A method of forming an isolated well in a substrate, the method comprising the steps of: forming an insulation layer on the substrate; forming a barrier layer on the insulation layer; patterning the barrier layer and the insulation layer to form an insulation region on the substrate and a barrier region on the insulation region; etching the substrate using the barrier region and the insulation region as a mask to thereby form a trench in the substrate, the trench defining an active region surface on the substrate, the active region surface underlying the insulation region and the barrier region; p1 forming a second insulation layer on the substrate, covering the barrier region; planarizing the second insulation layer to expose the barrier region and leave a portion of the second insulation layer in the trench; anisotropically etching the portion of the second insulation layer in the trench adjacent the barrier region to expose a sidewall portion of the barrier region and leave a trench insulation region in the trench, the trench insulation region extending above the trench sidewall; implanting ions into the substrate through the trench insulation region and the trench sidewall using the barrier region as a mask; removing the barrier region; and implanting ions into the substrate through the active region surface.
Claim 13
Independent Claim
213 words
A method of forming an isolated well in a substrate, the method comprising the steps of: forming an insulation layer on the substrate; forming a barrier layer on the insulation layer; patterning the barrier layer and the insulation layer to form an insulation region on the substrate and a barrier region on the insulation region; etching the substrate using the barrier region and the insulation region as a mask to thereby form a trench in the substrate, the trench defining an active region surface on the substrate, the active region surface underlying the insulation region and the barrier region; p1 forming a second insulation layer on the substrate, covering the barrier region; planarizing the second insulation layer to expose the barrier region and leave a portion of the second insulation layer in the trench; anisotropically etching the portion of the second insulation layer in the trench adjacent the barrier region to expose a sidewall portion of the barrier region and leave a trench insulation region in the trench, the trench insulation region extending above the trench sidewall; implanting ions into the substrate through the trench insulation region and the trench sidewall using the barrier region as a mask; removing the barrier region; and implanting ions into the substrate through the active region surface.
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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) | 2001-08-17 | 2002-02-16 | 2002-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-17 | 2006-02-16 | 2006-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-17 | 2010-02-16 | 2010-08-18 | $7700.00 | Window Closed / Lapsed |