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US4967247A Expired / Lapsed US ⏱️ 0.0 years remaining

Vertical dynamic random access memory

Assignee: Hitachi Ltd
•
Filing: 1988-12-02
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Granted: 1990-10-30
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Expires: 2008-12-02
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Abstract

Abstract A semiconductor memory comprises a switching device and a charge-storage device disposed at the upper and lower sides, respectively, of each of semiconductor islands. The islands are formed on a semiconductor substrate that is completely isolated from the semiconductor substrate by an insulator. The switching device and charge-storage device are substantially the same width. The memory cell structure is extremely small. The cell structure is highly resistant to alpha-particles and is formed self-aligned. During manufacture, the SiO 2 island is oxidized adjacent its lower end to insulate the island from the substrate.

Inventors

  • 👤 Toru Kaga
  • 👤 Yoshifumi Kawamoto
  • 👤 Hideo Sunami

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 21:27
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/30; H10B12/39; H10B12/395; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01346; H10B12/01; H10B12/02; H10B12/03; H10B12/038; H10B12/0383; H10B12/05; H10D1/00; H10D1/01; H10D1/045; H10D1/047; H10D30/00; H10D30/60; H10D30/63; H10D62/00; H10D62/10; H10D62/117; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10D64/60; H10D64/66; H10D64/68

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 64 words
A semiconductor memory integrated circuit comprising: at least one pair of switching and charge-storage devices are disposed adjacent upper and lower sides, respectively, of each of a plurality of semiconductor islands which are formed on a semiconductor substrate, the islands being isolated from said semiconductor substrate and from each other by an insulator means, said switching and charge-storage devices having substantially the same width.
Claim 2
Dependent Claim 64 words
A semiconductor memory integrated circuit comprising: at least one pair of switching and charge-storage devices are disposed adjacent upper and lower sides, respectively, of each of a plurality of semiconductor islands which are formed on a semiconductor substrate, the islands being isolated from said semiconductor substrate and from each other by an insulator means, said switching and charge-storage devices having substantially the same width.
Claim 3
Dependent Claim 130 words
A semiconductor memory comprising: a switching device and a charge storage device which are disposed adjacent upper and lower sides, respectively, of each semiconductor island which is formed on a semiconductor substrate, each island being isolated from said semiconductor substrate by means of an insulator, an impurity doped layer being formed in a surface region of at least a sidewall of a lower part of each semiconductor island, each semiconductor island being of a first conductivity type, said impurity doped layer being of a second conductivity type which is opposite to said first conductivity type, said charge-storage device comprising a capacitor insulator along a surface of said impurity doped layer, and an electrode formed on said capacitor insulator, said switching device and said charge-storage device having substantially the same width.
Claim 4
Dependent Claim 130 words
A semiconductor memory comprising: a switching device and a charge storage device which are disposed adjacent upper and lower sides, respectively, of each semiconductor island which is formed on a semiconductor substrate, each island being isolated from said semiconductor substrate by means of an insulator, an impurity doped layer being formed in a surface region of at least a sidewall of a lower part of each semiconductor island, each semiconductor island being of a first conductivity type, said impurity doped layer being of a second conductivity type which is opposite to said first conductivity type, said charge-storage device comprising a capacitor insulator along a surface of said impurity doped layer, and an electrode formed on said capacitor insulator, said switching device and said charge-storage device having substantially the same width.
Claim 5
Dependent Claim 15 words
The semiconductor memory according to claim 2 wherein said semiconductor island and substrate are silicon.
Claim 6
Dependent Claim 30 words
The semiconductor memory according to claim 2 wherein said switching device is a vertical metal-insulator-semiconductor (MIS) transistor having a cylindrical gate electrode formed on a sidewall of the semiconductor island.
Claim 7
Dependent Claim 44 words
The semiconductor memory according to claim 2 wherein said semiconductor islands are arranged in lines, said linear semiconductor islands being isolated from each other at constant regular spacings by an insulator, the switching and charge-storage devices are isolated from each other by said insulator.
Claim 8
Dependent Claim 43 words
The semiconductor memory according to claim 2 wherein the semiconductor islands are isolated from each other by an insulator and are arranged at regular spacings, each semiconductor island having at least one pair of switching and charge-storage devices to form an integrated circuit.
Claim 9
Dependent Claim 32 words
The semiconductor memory according to claim 6 further including at least one additional semiconductor island, said additional semiconductor island having a gate electrode and a contact for connection with a peripheral circuit.
Claim 10
Dependent Claim 87 words
A semiconductor memory comprising: a switching device and a charge-storage device which are disposed adjacent upper and lower sides, respectively, of each of a plurality of semiconductor islands which are formed on a semiconductor substrate, the semiconductor islands being isolated from each other and from said semiconductor substrate by an insulator means and being arranged at regular spacings, each semiconductor island having at least one pair of switching and charge storage devices to form an integrated circuit, said switching and charge-storage devices having substantially the same width.
Claim 11
Dependent Claim 87 words
A semiconductor memory comprising: a switching device and a charge-storage device which are disposed adjacent upper and lower sides, respectively, of each of a plurality of semiconductor islands which are formed on a semiconductor substrate, the semiconductor islands being isolated from each other and from said semiconductor substrate by an insulator means and being arranged at regular spacings, each semiconductor island having at least one pair of switching and charge storage devices to form an integrated circuit, said switching and charge-storage devices having substantially the same width.
Claim 12
Dependent Claim 32 words
The semiconductor memory according to claim 8 further including at least one additional semiconductor island, said additional semiconductor island having a gate electrode and a contact for connection with a peripheral circuit.
Claim 13
Dependent Claim 15 words
The semiconductor memory according to claim 8 wherein said semiconductor island and substrate are silicon.
Claim 14
Dependent Claim 81 words
The semiconductor memory according to claim 8 wherein an impurity doped layer is formed in a surface region of at least a sidewall of a lower part of each semiconductor island, each semiconductor island being of a first conductivity type, said impurity doped layer being of a second conductivity type which is opposite to said first conductivity type, said charge-storage device comprising a capacitor insulator along a surface of said impurity doped layer and an electrode formed on said capacitor insulator.
Claim 15
Dependent Claim 45 words
The semiconductor memory according to claim 8 wherein said semiconductor islands are arranged in lines, said linear semiconductor islands being isolated from each other at the constant regular spacings by an insulator, the switching and charge-storage devices are isolated from each other by said insulator.
Claim 16
Dependent Claim 139 words
A semiconductor memory comprising: a body; an insulator disposed on the body; a semiconductor island which is disposed on the insulator and completely electrically isolated from the body by the insulator; a capacitor insulator disposed on a sidewall of the semiconductor island; a plate electrode disposed on the capacitor insulator; a gate insulator disposed on the sidewall of the semiconductor island; a gate electrode disposed on the gate insulator; a first high impurity doped region provided in a part of the semiconductor island, the first high impurity doped region operating as one of a source and a drain; a second high impurity doped region provided in a part of the semiconductor island, the second high impurity doped region operating as one of a drain and a source; and, a data line electrically coupled to the second high impurity region.
Claim 17
Dependent Claim 139 words
A semiconductor memory comprising: a body; an insulator disposed on the body; a semiconductor island which is disposed on the insulator and completely electrically isolated from the body by the insulator; a capacitor insulator disposed on a sidewall of the semiconductor island; a plate electrode disposed on the capacitor insulator; a gate insulator disposed on the sidewall of the semiconductor island; a gate electrode disposed on the gate insulator; a first high impurity doped region provided in a part of the semiconductor island, the first high impurity doped region operating as one of a source and a drain; a second high impurity doped region provided in a part of the semiconductor island, the second high impurity doped region operating as one of a drain and a source; and, a data line electrically coupled to the second high impurity region.
Claim 18
Dependent Claim 71 words
The semiconductor memory according to claim 13 wherein the semiconductor island is made of silicon and the body is made of silicon; the gate insulator includes at least a SiO 2 film; and, the capacitor insulator includes at least one selected from among a SiO 2 film, a Si 3 N 4 film, a Ta 2 O 5 film, NKO 3 Pb(Zr 1-x Ti x ) film, and a combination thereof.
Claim 19
Dependent Claim 37 words
The semiconductor memory according to claim 14 wherein the semiconductor island, the plate electrode, the capacitor insulator, the gate insulator, and the gate electrode are disposed at respective fixed positions which are determined only by process conditions.
Claim 20
Dependent Claim 39 words
The semiconductor memory according to claim 18 further including a plurality of the semiconductor islands, the spacing between each pair of adjacent semiconductor islands in a word line direction being smaller than the spacing in a data line direction.
Claim 21
Dependent Claim 49 words
The semiconductor memory according to claim 13 wherein the data line is disposed above the word line through an insulator; and, the data line is disposed substantially horizontally, a lower surface of the data line being on substantially the same level as an upper surface of the semiconductor island.
Claim 22
Dependent Claim 19 words
The semiconductor memory according to claim 13 wherein the semiconductor island is columnar and the gate electrode is annular.
Claim 23
Dependent Claim 23 words
A semiconductor memory according to claim 18 wherein said switching device is a vertical metal insulator-semiconductor (MIS) and the gate electrode is cylindrical.
Claim 24
Dependent Claim 132 words
A semiconductor memory comprising: a body; a first insulator portion provided on the body; a semiconductor island which is provided on the insulator and completely electrically isolated from the body by the insulator; a second insulator portion provided on a sidewall of the semiconductor island; a plate electrode provided adjacent the second insulator portion; a gate electrode provided adjacent the second insulator portion; a first high impurity doped region provided in a part of the semiconductor island; a second high impurity doped region provided in a part of the semiconductor island; a data line electrically coupled to one of the high impurity doped regions; wherein the semiconductor island, the plate electrode, the second insulator portion, and the gate electrode are provided at respective fixed positions which are determined only by process conditions.
Claim 25
Dependent Claim 132 words
A semiconductor memory comprising: a body; a first insulator portion provided on the body; a semiconductor island which is provided on the insulator and completely electrically isolated from the body by the insulator; a second insulator portion provided on a sidewall of the semiconductor island; a plate electrode provided adjacent the second insulator portion; a gate electrode provided adjacent the second insulator portion; a first high impurity doped region provided in a part of the semiconductor island; a second high impurity doped region provided in a part of the semiconductor island; a data line electrically coupled to one of the high impurity doped regions; wherein the semiconductor island, the plate electrode, the second insulator portion, and the gate electrode are provided at respective fixed positions which are determined only by process conditions.
Claim 26
Dependent Claim 22 words
The semiconductor memory according to claim 20 wherein the semiconductor island is made of silicon and the body is made of silicon.
Claim 27
Dependent Claim 19 words
The semiconductor memory according to claim 21 wherein the second insulator portion includes at least a SiO 2 film.
Claim 28
Dependent Claim 43 words
The semiconductor memory according to claim 22 wherein the second insulator portion further includes at least one selected from among a Si 3 N 4 film, a Ta 2 O 5 film, KNO 3 Pb(Zr 1-x Ti x ) film, and combinations thereof.
Claim 29
Dependent Claim 39 words
The semiconductor memory according to claim 22 further including a plurality of the semiconductor islands, the spacing between each pair of adjacent semiconductor islands in a word line direction being smaller than the spacing in a data line direction.
Claim 30
Dependent Claim 19 words
The semiconductor memory according to claim 22 wherein the semiconductor island is columnar and the gate electrode is annular.
Claim 31
Dependent Claim 22 words
The semiconductor memory according to claim 22 wherein the data line is disposed above the word line through the first insulator portion.
Claim 32
Dependent Claim 37 words
The semiconductor memory according to claim 26 wherein the data line is disposed substantially horizontally and a lower surface of the data line is on substantially the same level as an upper surface of the semiconductor island.

References Cited (Backward Citations)

JPS5919366A Cited
US4638460A Cited
US4737829A Cited
JPS6236851A Cited
US4704705A Cited
US4686552A Cited
JPS62286269A Cited
JPS639142A Cited
JPS6310557A Cited
US4833516A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-10-29 1994-04-30 1994-10-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-10-29 1998-04-30 1998-10-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-10-29 2002-04-30 2002-10-30 $7700.00 Window Closed / Lapsed

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