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US5512767A Expired / Lapsed US ⏱️ 0.0 years remaining

Trench capacitor field shield with sidewall contact

Assignee: International Business Machines Corp
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Filing: 1994-12-13
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Granted: 1996-04-30
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Expires: 2014-12-13
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Abstract

Abstract Structures and methods are presented for forming a field shield for a trench capacitor for a memory cell with a contact through insulator along a sidewall of the trench to a desired region of the semiconducting substrate. The desired region is typically held at a substantially fixed potential; in any case it does not include a node diffusion.

Inventors

  • 👤 Wendell P. Noble, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 03:17
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/30; H10B12/37

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 93 words
A storage capacitor having two electrodes formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the capacitor comprising: a layer of insulator on walls of the trench; a layer of electrically conductive material on said layer of insulator; a node diffusion, one of the electrodes contacting said node diffusion and an electrically conductive member connected to said layer of electrically conductive material, extending through a sidewall portion of said layer of insulator, and contacting a selected region of the substrate other than said node diffusion.
Claim 2
Dependent Claim 93 words
A storage capacitor having two electrodes formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the capacitor comprising: a layer of insulator on walls of the trench; a layer of electrically conductive material on said layer of insulator; a node diffusion, one of the electrodes contacting said node diffusion and an electrically conductive member connected to said layer of electrically conductive material, extending through a sidewall portion of said layer of insulator, and contacting a selected region of the substrate other than said node diffusion.
Claim 3
Dependent Claim 16 words
A capacitor as recited in claim 1, wherein said selected region is below the node diffusion.
Claim 4
Dependent Claim 23 words
A capacitor as recited in claim 1, wherein said electrically conductive material is located adjacent only an upper sidewall portion of the trench.
Claim 5
Dependent Claim 26 words
A capacitor as recited in claim 3, wherein said electrically conductive material is laterally adjacent only a region of the substrate of a single conductivity type.
Claim 6
Dependent Claim 21 words
A capacitor as recited in claim 1, wherein said electrically conductive material is positioned adjacent only the sidewalls of the trench.
Claim 7
Dependent Claim 38 words
A capacitor as recited in claim 1, wherein said layer of insulator is also deposited on the bottom of the trench and said electrically conductive material is positioned adjacent the sidewalls and the bottom surface of the trench.
Claim 8
Dependent Claim 20 words
A capacitor as recited in claim 1, wherein said electrically conductive member and said electrically conductive material comprise doped polysilicon.
Claim 9
Dependent Claim 22 words
A capacitor as recited in claim 1, wherein said insulator comprises at least one from the group; silicon dioxide and silicon nitride.
Claim 10
Dependent Claim 110 words
A storage capacitor formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the semiconductor substrate having a plurality of layers of differing impurity type and concentration, at least one of which is held at a substantially fixed potential, the capacitor comprising: a layer of insulator deposited on walls of the trench; a layer of electrically conductive material deposited on said layer of insulator; and an electrically conductive member connected to said layer of electrically conductive material, extending though a sidewall portion of said layer of insulator, and contacting a selected region of the substrate that is held at a substantially fixed potential.
Claim 11
Dependent Claim 110 words
A storage capacitor formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the semiconductor substrate having a plurality of layers of differing impurity type and concentration, at least one of which is held at a substantially fixed potential, the capacitor comprising: a layer of insulator deposited on walls of the trench; a layer of electrically conductive material deposited on said layer of insulator; and an electrically conductive member connected to said layer of electrically conductive material, extending though a sidewall portion of said layer of insulator, and contacting a selected region of the substrate that is held at a substantially fixed potential.
Claim 12
Dependent Claim 23 words
A capacitor as recited in claim 9, wherein said electrically conductive material is located adjacent only an upper sidewall portion of the trench.
Claim 13
Dependent Claim 26 words
A capacitor as recited in claim 10, wherein said electrically conductive material is laterally adjacent only a region of the substrate of a single conductivity type.
Claim 14
Dependent Claim 21 words
A capacitor as recited in claim 9, wherein said electrically conductive material is positioned adjacent only the sidewalls of the trench.
Claim 15
Dependent Claim 38 words
A capacitor as recited in claim 9, wherein said layer of insulator is also deposited on the bottom of the trench and said electrically conductive material is positioned adjacent the sidewalls and the bottom surface of the trench.
Claim 16
Dependent Claim 20 words
A capacitor as recited in claim 9, wherein said electrically conductive member and said electrically conductive material comprise doped polysilicon.
Claim 17
Dependent Claim 22 words
A capacitor as recited in claim 9, wherein said insulator comprises at least one from the group: silicon dioxide and silicon nitride.
Claim 18
Dependent Claim 31 words
A capacitor as recited in claim 9, wherein said region contacted is one from the group: n- well, p- well, n+ buried plate, p+ buried plate, n+ substrate, and p+ substrate.
Claim 19
Dependent Claim 146 words
A memory cell with a transfer device and a storage capacitor, the storage capacitor formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the semiconductor substrate having a plurality of layers of differing impurity type and concentration, at least one of which is held at a fixed potential, the memory cell comprising: a layer of insulator on walls of the trench; a layer of electrically conductive material on said layer of insulator; an electrically conductive member connected to said layer of electrically conductive material, extending though a sidewall portion of said layer of insulator, and contacting a selected region of the substrate that is held at a fixed potential; and a transfer device comprising a bit line contact and diffusion, a gate, and a node diffusion, said node diffusion electrically connected to a storage electrode of the capacitor.
Claim 20
Dependent Claim 146 words
A memory cell with a transfer device and a storage capacitor, the storage capacitor formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the semiconductor substrate having a plurality of layers of differing impurity type and concentration, at least one of which is held at a fixed potential, the memory cell comprising: a layer of insulator on walls of the trench; a layer of electrically conductive material on said layer of insulator; an electrically conductive member connected to said layer of electrically conductive material, extending though a sidewall portion of said layer of insulator, and contacting a selected region of the substrate that is held at a fixed potential; and a transfer device comprising a bit line contact and diffusion, a gate, and a node diffusion, said node diffusion electrically connected to a storage electrode of the capacitor.
Claim 21
Dependent Claim 123 words
A memory cell with a transfer device and a capacitor, the capacitor formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the memory cell comprising: a layer of insulator on walls of the trench; a layer of electrically conductive material on said layer of insulator; a transfer device comprising a bit line contact and a diffusion, a gate, and a node diffusion, said node diffusion electrically connected to a storage node of the capacitor; and an electrically conductive member connected to said layer of electrically conductive material, said member extending through a sidewall portion of said layer of insulator, said member contacting a selected region of the substrate, said region not contacting said node diffusion.
Claim 22
Dependent Claim 123 words
A memory cell with a transfer device and a capacitor, the capacitor formed in a trench having sidewalls and a bottom wall, the trench located in a semiconductor substrate, the memory cell comprising: a layer of insulator on walls of the trench; a layer of electrically conductive material on said layer of insulator; a transfer device comprising a bit line contact and a diffusion, a gate, and a node diffusion, said node diffusion electrically connected to a storage node of the capacitor; and an electrically conductive member connected to said layer of electrically conductive material, said member extending through a sidewall portion of said layer of insulator, said member contacting a selected region of the substrate, said region not contacting said node diffusion.
Claim 23
Dependent Claim 68 words
A trench sidewall connector in a semiconductor substrate, comprising: a semiconductor substrate; a trench in the substrate, said trench having a sidewall; and a conductive layer within said trench at least in part spaced from said sidewall, said layer having an outer and an inner surface, said layer making electrical contain with a portion of said sidewall, said layer held at a substantially fixed potential when in operation.
Claim 24
Dependent Claim 68 words
A trench sidewall connector in a semiconductor substrate, comprising: a semiconductor substrate; a trench in the substrate, said trench having a sidewall; and a conductive layer within said trench at least in part spaced from said sidewall, said layer having an outer and an inner surface, said layer making electrical contain with a portion of said sidewall, said layer held at a substantially fixed potential when in operation.

References Cited (Backward Citations)

US4751558A Cited
US4918502A Cited
US4987470A Cited
US5111259A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-04-30 1999-10-30 2000-04-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-04-30 2003-10-30 2004-04-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-04-30 2007-10-30 2008-04-30 $7700.00 Window Closed / Lapsed

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