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US5436477A Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor memory device with high dielectric capacitor structure

Assignee: Mitsubishi Electric Corp
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Filing: 1994-06-17
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Granted: 1995-07-25
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Expires: 2014-06-17
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Abstract

Abstract Transfer gate transistors are formed on a main surface of a semiconductor substrate. The transfer gate transistors have impurity regions for serving as source/drain regions. A first interlayer insulating film having a substantially flat upper surface is formed to cover the transfer gate transistors. The first interlayer insulating film is provided with contact holes reaching the impurity regions. Plugs are formed in the contact holes. Capacitors are only formed on the flat upper surface of the first interlayer insulating film. Lower electrodes of the capacitors and the plugs are electrically connected with each other through barrier layers. Thus, it is possible to improve capacitances of capacitors in a DRAM.

Inventors

  • 👤 Yasushi Hashizume
  • 👤 Hiroki Shinkawata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 08:05
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/30; H10B12/31

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 178 words
A semiconductor memory device comprising: a semiconductor substrate of a first conductivity type having a main surface; an impurity region of a second conductivity type formed in said main surface of said semiconductor substrate; an interlayer insulating film, formed on said main surface of said semiconductor substrate, having a contact hole reaching a surface of said impurity region; a capacitor, formed only on an upper surface portion of said interlayer insulating film excluding a portion on said contact hole, including a first electrode, a high dielectric film consisting of a material having a high dielectric constant formed on said first electrode, and a second electrode formed on said high dielectric film; and a conductor part formed at least in said contact hole for electrically connecting said first or second electrode with said impurity region, wherein said conductor part includes a plug electrode embedded in said contact hole, said high dielectric film and said first electrode extend onto said plug electrode, and said second electrode is formed on said high dielectric film excluding a portion on said contact hole.
Claim 2
Dependent Claim 178 words
A semiconductor memory device comprising: a semiconductor substrate of a first conductivity type having a main surface; an impurity region of a second conductivity type formed in said main surface of said semiconductor substrate; an interlayer insulating film, formed on said main surface of said semiconductor substrate, having a contact hole reaching a surface of said impurity region; a capacitor, formed only on an upper surface portion of said interlayer insulating film excluding a portion on said contact hole, including a first electrode, a high dielectric film consisting of a material having a high dielectric constant formed on said first electrode, and a second electrode formed on said high dielectric film; and a conductor part formed at least in said contact hole for electrically connecting said first or second electrode with said impurity region, wherein said conductor part includes a plug electrode embedded in said contact hole, said high dielectric film and said first electrode extend onto said plug electrode, and said second electrode is formed on said high dielectric film excluding a portion on said contact hole.
Claim 3
Dependent Claim 55 words
A semiconductor memory device in accordance with claim 1, wherein said first electrode is made of at least one material selected from a group of Ir, Pt, Pd, Rh, Ni, W, a Pt alloy, a Pd alloy, an Rh alloy, an Ni alloy, a W alloy, RuO 2 , SrRuO 3 and ReO 2 .
Claim 4
Dependent Claim 23 words
A semiconductor memory device in accordance with claim 1, wherein said high dielectric film is a polycrystalline film having a perovskite crystal structure.
Claim 5
Dependent Claim 177 words
A semiconductor memory device comprising: a semiconductor substrate of a first conductivity type having a main surface; an impurity region of a second conductivity type formed in said main surface of said semiconductor substrate; an interlayer insulating film, formed on said main surface of said semiconductor substrate, having a contact hole reaching a surface of said impurity region; a capacitor, formed only on an upper surface portion of said interlayer insulating film excluding a portion on said contact hole, including a first electrode, a high dielectric film consisting of a material having a high dielectric constant formed on said first electrode, and a second electrode formed on said high dielectric film; a conductor part formed at least in said contact hole for electrically connecting said first or second electrode with said impurity region; a side wall insulating film formed between a side wall of said high dielectric film and an upper end portion of said contact hole; and said second electrode formed extending from a portion on said side wall insulating film onto said high dielectric film.
Claim 6
Dependent Claim 177 words
A semiconductor memory device comprising: a semiconductor substrate of a first conductivity type having a main surface; an impurity region of a second conductivity type formed in said main surface of said semiconductor substrate; an interlayer insulating film, formed on said main surface of said semiconductor substrate, having a contact hole reaching a surface of said impurity region; a capacitor, formed only on an upper surface portion of said interlayer insulating film excluding a portion on said contact hole, including a first electrode, a high dielectric film consisting of a material having a high dielectric constant formed on said first electrode, and a second electrode formed on said high dielectric film; a conductor part formed at least in said contact hole for electrically connecting said first or second electrode with said impurity region; a side wall insulating film formed between a side wall of said high dielectric film and an upper end portion of said contact hole; and said second electrode formed extending from a portion on said side wall insulating film onto said high dielectric film.
Claim 7
Dependent Claim 37 words
A semiconductor memory device in accordance with claim 4, wherein each of said second electrode and said conductor part is made of at least one material selected from a group of TiN, Pt and RuO 2 .
Claim 8
Dependent Claim 257 words
A semiconductor memory device comprising: a semiconductor substrate of a first conductivity type having a main surface; an MOS transistor formed by first and second impurity regions of a second conductivity type being provided in said main surface of said semiconductor substrate defining a channel forming region, and a gate electrode being formed on said channel forming region with a gate insulating film interposed therebetween; a first interlayer insulating film, being formed on said main surface of said semiconductor substrate to cover said MOS transistor, having a contact hole reaching a surface of said first impurity region; a bit line formed in said first interlayer insulating film to be electrically connected with said second impurity region; a capacitor, being formed only on an upper surface portion of said first interlayer insulating film excluding a portion on said contact hole, including a first electrode, a high dielectric film consisting of a material having a high dielectric constant formed on said first electrode, and a second electrode formed on said high dielectric film; a conductor part formed at least in said contact hole for electrically connecting said first or second electrode with said first impurity region; and a second interlayer insulating film being formed to cover a surface of said second electrode of said capacitor, wherein said conductor part includes a plug electrode embedded in said contact hole, said high dielectric film and said first electrode extend onto said plug electrode, and said second electrode is formed on said high dielectric film excluding a portion on said contact hole.
Claim 9
Dependent Claim 257 words
A semiconductor memory device comprising: a semiconductor substrate of a first conductivity type having a main surface; an MOS transistor formed by first and second impurity regions of a second conductivity type being provided in said main surface of said semiconductor substrate defining a channel forming region, and a gate electrode being formed on said channel forming region with a gate insulating film interposed therebetween; a first interlayer insulating film, being formed on said main surface of said semiconductor substrate to cover said MOS transistor, having a contact hole reaching a surface of said first impurity region; a bit line formed in said first interlayer insulating film to be electrically connected with said second impurity region; a capacitor, being formed only on an upper surface portion of said first interlayer insulating film excluding a portion on said contact hole, including a first electrode, a high dielectric film consisting of a material having a high dielectric constant formed on said first electrode, and a second electrode formed on said high dielectric film; a conductor part formed at least in said contact hole for electrically connecting said first or second electrode with said first impurity region; and a second interlayer insulating film being formed to cover a surface of said second electrode of said capacitor, wherein said conductor part includes a plug electrode embedded in said contact hole, said high dielectric film and said first electrode extend onto said plug electrode, and said second electrode is formed on said high dielectric film excluding a portion on said contact hole.
Claim 10
Dependent Claim 34 words
A semiconductor memory device in accordance with claim 4, wherein the side wall insulating film is only formed between the side wall and the upper end portion and not on the high dielectric film.

References Cited (Backward Citations)

US5046043A Cited
US5109357A Cited
US5043049A Cited
JPH0321062A Cited
WO1991001398A1 Cited
WO1991001281A1 Cited
JPH03142966A Cited
DE4107165A1 Cited
EP0497982A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-07-24 1999-01-23 1999-07-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-07-24 2003-01-23 2003-07-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-07-24 2007-01-23 2007-07-25 $7700.00 Window Closed / Lapsed

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