US5945704A
Expired / Lapsed
US
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Trench capacitor with epi buried layer
Assignee: Infineon Technologies AG
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Filing: 1998-06-26
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Granted: 1999-08-31
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Expires: 2018-06-26
Abstract
Abstract A trench capacitor with an epi layer in the lower portion of the trench. The epi layer serves as the buried plate of the trench capacitor. A diffusion region surrounds the lower portion of the trench to enhance the dopant concentration of the epi layer. The diffusion region is formed by, for example, gas phase doping, plasma doping, or plasma immersion ion implantation.
Inventors
- 👤 Martin Schrems
- 👤 Jack Mandelman
- 👤 Joachim Hoepfner
- 👤 Herbert Schaefer
- 👤 Reinhard Stengl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:01
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/038; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/66; H10D1/665
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
76 words
A semiconductor integrated circuit comprising: a trench capacitor, wherein the trench capacitor comprises an epitaxial layer lining the lower portion of sidewalls of a trench below an oxide collar which lines an upper portion of the trench, the epitaxial layer abutting the oxide collar in the trench such that the oxide collar and the epitaxial layer do not overlap on the sidewalls of the trench; and a diffusion region surrounding the lower portion of the trench.
Claim 2
Dependent Claim
76 words
A semiconductor integrated circuit comprising: a trench capacitor, wherein the trench capacitor comprises an epitaxial layer lining the lower portion of sidewalls of a trench below an oxide collar which lines an upper portion of the trench, the epitaxial layer abutting the oxide collar in the trench such that the oxide collar and the epitaxial layer do not overlap on the sidewalls of the trench; and a diffusion region surrounding the lower portion of the trench.
Claim 3
Dependent Claim
38 words
The semiconductor integrated circuit as recited in claim 1, wherein the trench capacitor is formed in a substrate, the substrate having a dopant concentration and the diffusion region having a dopant concentration greater than the substrate dopant concentration.
Claim 4
Dependent Claim
24 words
The semiconductor integrated circuit as recited in claim 1, further comprises a continuous dielectric layer formed on the epitaxial layer and the oxide collar.
Claim 5
Dependent Claim
33 words
The semiconductor integrated circuit as recited in claim 1, wherein the epitaxial layer includes a reduced surface roughness over a roughness of the trench sidewalls such that improved capacitor breakdown voltage is provided.
Claim 6
Dependent Claim
24 words
The semiconductor integrated circuit as recited in claim 1, wherein the epitaxial layer is substantially defectless such that improved capacitor breakdown voltage is provided.
Claim 7
Dependent Claim
32 words
The semiconductor integrated circuit as recited in claim 1, wherein the diffusion region has dopants provided by one of a gas phased doping, a plasma doping and a plasma immersion ion implantation.
Claim 8
Dependent Claim
15 words
The semiconductor integrated circuit as recited in claim 1, wherein the epitaxial layer includes polysilicon.
Claim 9
Dependent Claim
21 words
The semiconductor integrated circuit as recited in claim 1, wherein the epitaxial layer is comprised of a plurality of epitaxial layers.
Claim 10
Dependent Claim
24 words
The semiconductor integrated circuit as recited in claim 1, wherein the diffusion region includes a dopant concentration of greater than about 1×10 18 atoms/cc.
Claim 11
Dependent Claim
30 words
The semiconductor integrated circuit as recited in claim 1, wherein the diffusion region includes a surface junction depth of about 0.1 times to about 0.7 times a minimum feature size.
References Cited (Backward Citations)
US5629226A
Cited
US5731226A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-30 | 2003-03-01 | 2003-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-30 | 2007-03-01 | 2007-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-30 | 2011-03-01 | 2011-08-31 | $7700.00 | Window Closed / Lapsed |