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Electrodes comprising conductive perovskite-seed layers for perovskite dielectrics

Assignee: Texas Instruments Inc
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Filing: 1995-06-07
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Granted: 1996-12-31
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Expires: 2015-06-07
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Abstract

Abstract A preferred embodiment of this invention comprises a perovskite-seed layer (e.g. calcium ruthenate 40) between a conductive oxide layer (e.g. ruthenium oxide 36) and a perovskite dielectric material (e.g. barium strontium titanate 42), wherein the perovskite-seed layer and the conductive oxide layer each comprise the same metal. The metal should be conductive in its metallic state and should remain conductive when partially or fully oxidized. Generally, the perovskite-seed layer has a perovskite or perovskite-like crystal structure and lattice parameters which are similar to the perovskite dielectric layer formed thereon. At a given deposition temperature, the crystal quality and other properties of the perovskite dielectric will generally be enhanced by depositing it on a surface having a similar crystal structure. Undesirable crystal structure formation will generally be minimized and lower processing temperatures may be used to deposit the perovskite dielectric layer. Another benefit of this electrode system is that the perovskite-seed layer should do little or no reduction of the perovskite dielectric layer.

Inventors

  • 👤 Scott R. Summerfelt
  • 👤 Howard R. Beratan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 02:25
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/50

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 60 words
A microelectronic structure comprising: a conductive oxide layer comprising a first metal; a conductive perovskite-seed layer comprising said first metal overlying said conductive oxide layer; and a perovskite dielectric layer overlying said perovskite-seed layer, whereby the similar crystal structure of the perovskite-seed layer improves the crystal quality of the perovskite dielectric layer and minimizes the formation of non-perovskite crystal structures.
Claim 2
Dependent Claim 60 words
A microelectronic structure comprising: a conductive oxide layer comprising a first metal; a conductive perovskite-seed layer comprising said first metal overlying said conductive oxide layer; and a perovskite dielectric layer overlying said perovskite-seed layer, whereby the similar crystal structure of the perovskite-seed layer improves the crystal quality of the perovskite dielectric layer and minimizes the formation of non-perovskite crystal structures.
Claim 3
Dependent Claim 18 words
The structure of claim 1, wherein said first metal is ruthenium and said conductive oxide is ruthenium dioxide.
Claim 4
Dependent Claim 18 words
The structure of claim 1, wherein said first metal is iridium and said conductive oxide is iridium oxide.
Claim 5
Dependent Claim 12 words
The structure of claim 1, wherein said perovskite-seed layer is calcium ruthenate.
Claim 6
Dependent Claim 32 words
The structure of claim 1, wherein said perovskite-seed layer is selected from the group consisting of: SrRuO 3 , BaRuO 3 , CaIrO 3 , SrIrO 3 , and BaIrO 3 .
Claim 7
Dependent Claim 14 words
The structure of claim 1, wherein said perovskite dielectric layer is barium strontium titanate.
Claim 8
Dependent Claim 41 words
The structure of claim 1, wherein said perovskite dielectric layer is selected from the group consisting of: (Ba,Sr,Pb)(Ti,Zr)O 3 , (Pb,La)(Zr,Ti)O 3 , bismuth titanate, potassium tantalate, lead scandium tantalate, lead niobate, potassium niobate, lead zinc niobate, and lead magnesium niobate.
Claim 9
Dependent Claim 15 words
The structure of claim 1, further comprising an upper electrode overlying said perovskite dielectric layer.
Claim 10
Dependent Claim 12 words
The structure of claim 8, wherein said upper electrode is titanium nitride.
Claim 11
Dependent Claim 21 words
The structure of claim 1, further comprising said conductive oxide layer overlying a first metallic layer composed of said first metal.
Claim 12
Dependent Claim 21 words
The structure of claim 1, wherein said conductive oxide layer further comprises unoxidized and partially oxidized forms of said first metal.
Claim 13
Dependent Claim 38 words
A microelectronic capacitor structure comprising: a ruthenium dioxide layer; a calcium ruthenate layer overlying said ruthenium dioxide layer; a barium strontium titanate layer overlying said calcium ruthenate layer; and an upper electrode overlying said barium strontium titanate layer.
Claim 14
Dependent Claim 38 words
A microelectronic capacitor structure comprising: a ruthenium dioxide layer; a calcium ruthenate layer overlying said ruthenium dioxide layer; a barium strontium titanate layer overlying said calcium ruthenate layer; and an upper electrode overlying said barium strontium titanate layer.
Claim 15
Dependent Claim 38 words
A microelectronic capacitor structure comprising: an iridium oxide layer; a CaIrO 3 layer overlying said iridium oxide layer; a barium strontium titanate layer overlying said CaIrO 3 layer; and an upper electrode overlying said barium strontium titanate layer.
Claim 16
Dependent Claim 38 words
A microelectronic capacitor structure comprising: an iridium oxide layer; a CaIrO 3 layer overlying said iridium oxide layer; a barium strontium titanate layer overlying said CaIrO 3 layer; and an upper electrode overlying said barium strontium titanate layer.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-12-31 2000-07-01 2000-12-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-12-31 2004-07-01 2004-12-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-12-31 2008-07-01 2008-12-31 $7700.00 Window Closed / Lapsed

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