US6034393A
Expired / Lapsed
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Nonvolatile semiconductor memory device using trench isolation and manufacturing method thereof
Assignee: Renesas Electronics Corp
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Filing: 1997-12-01
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Granted: 2000-03-07
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Expires: 2017-12-01
Abstract
Abstract A nonvolatile semiconductor memory device with trench isolation having sufficient capability of isolating memory cells is provided. A trench formed as a line in the main surface of semiconductor substrate is filled with a first insulating film. On semiconductor substrate on both sides of trench, a first gate electrode is provided with a first oxide film interposed. On the first gate electrode, a second gate electrode is provided with a second insulating film interposed. An angle formed by a side wall upper surface of trench and the surface of semiconductor substrate is smaller than 90°.
Inventors
- 👤 Osamu Sakamoto
- 👤 Natsuo Ajika
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:57
CPC Classifications
H; H10; H10B; H10B41/00; H10B41/30; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0143; H10W10/0145; H10W10/10; H10W10/17
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
A nonvolatile semiconductor memory device using trench isolation, comprising: a silicon semiconductor substrate; a trench for said trench isolation formed as a line in a main surface of said semiconductor substrate; a first insulating film provided on said semiconductor substrate to fill said trench; a first gate electrode provided on said semiconductor substrate on both sides of said trench with a first oxide film interposed; and a second gate electrode formed on said first gate electrode with a second insulating film interposed therebetween; wherein an angle formed by a side wall surface of said trench and an upper surface of said semiconductor substrate is smaller than 90° C.; and said first oxide film is formed of SiO x N y or a material containing SiO x N y .
Claim 2
Dependent Claim
129 words
A nonvolatile semiconductor memory device using trench isolation, comprising: a silicon semiconductor substrate; a trench for said trench isolation formed as a line in a main surface of said semiconductor substrate; a first insulating film provided on said semiconductor substrate to fill said trench; a first gate electrode provided on said semiconductor substrate on both sides of said trench with a first oxide film interposed; and a second gate electrode formed on said first gate electrode with a second insulating film interposed therebetween; wherein an angle formed by a side wall surface of said trench and an upper surface of said semiconductor substrate is smaller than 90° C.; and said first oxide film is formed of SiO x N y or a material containing SiO x N y .
Claim 3
Dependent Claim
84 words
The nonvolatile semiconductor memory device according to claim 1, wherein said second insulating film is formed of a material containing an oxide of same element as a main element constituting said semiconductor substrate, a material containing a nitride of same element as a main element constituting said semiconductor substrate, or a stacked film of a material containing an oxide of same element as a main element constituting said semiconductor substrate and a material containing a nitride of a main element constituting said semiconductor substrate.
Claim 4
Dependent Claim
50 words
The nonvolatile semiconductor memory device according to claim 2, wherein said second insulating film is formed of a material containing SiO 2 , a material containing Si x N y , or a stacked film of a material containing SiO 2 and a material containing Si x N y .
Claim 5
Dependent Claim
25 words
The nonvolatile semiconductor memory device according to claim 1, wherein said first insulating film does not contain any impurity providing conductivity to said semiconductor substrate.
Claim 6
Dependent Claim
49 words
The nonvolatile semiconductor memory device according to claim 1, wherein a portion where said first insulating film is in contact with a side wall of said first gate electrode is below an upper surface of said first gate electrode and above a lower surface of said first gate electrode.
Claim 7
Dependent Claim
121 words
A nonvolatile semiconductor memory device using trench isolation, comprising: a silicon semiconductor substrate; a trench for said trench isolation formed as a line in a main surface of said semiconductor substrate; a first insulating film provided on said semiconductor substrate to fill said trench; a first gate electrode provided on said semiconductor substrate on both sides of said trench with a first oxide film interposed; and a second gate electrode formed on said first gate electrode with a second insulating film interposed therebetween; wherein the width of said trench becomes narrower in the direction of a bottom of the trench, and said first oxide film is formed of SiO x N y or a material containing SiO x N y .
Claim 8
Dependent Claim
121 words
A nonvolatile semiconductor memory device using trench isolation, comprising: a silicon semiconductor substrate; a trench for said trench isolation formed as a line in a main surface of said semiconductor substrate; a first insulating film provided on said semiconductor substrate to fill said trench; a first gate electrode provided on said semiconductor substrate on both sides of said trench with a first oxide film interposed; and a second gate electrode formed on said first gate electrode with a second insulating film interposed therebetween; wherein the width of said trench becomes narrower in the direction of a bottom of the trench, and said first oxide film is formed of SiO x N y or a material containing SiO x N y .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-07 | 2003-09-06 | 2004-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-07 | 2007-09-06 | 2008-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-07 | 2011-09-06 | 2012-03-07 | $7700.00 | Window Closed / Lapsed |