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US6040594A Expired / Lapsed US ⏱️ 0.0 years remaining

High permittivity ST thin film and a capacitor for a semiconductor integrated circuit having such a thin film

Assignee: Fujitsu Ltd
•
Filing: 1998-12-04
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Granted: 2000-03-21
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Expires: 2018-12-04
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Abstract

Abstract A semiconductor integrated circuit integrating a high-permittivity thin film capacitor of strontium titanate on the same semiconductor chip, the thin film capacitor consisting of a pair of electrodes and essentially crystalline strontium titanate film therebetween which has a thin surface layer where concentration of titanium is higher than that of the rest of the crystalline strontium titanate film. In one embodiment according to the present invention, a thin film capacitor was fabricated by depositing a 200 nm thick film of strontium titanate at a temperature of 300° C. on a 10 nm thick amorphous titanium oxide film which eventually became the thin surface layer, and subsequent annealing of 250° C. for 30 min in an oxidation atmosphere. A structure and processes realized a thin film capacitor having a dielectric constant of 100 and leakage current density of 4×10 -7 A/cm 2 without degrading characteristics of transistors already fabricated in the same semiconductor chip.

Inventors

  • 👤 Seigen Otani

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 03:43
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D1/684; H10D84/00; H10D84/01; H10D84/02; H10D84/05

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 33 words
A high-permittivity thin film essentially consisting of strontium titanate (SrTiO 3 ) comprising a surface layer where concentration of titanium atoms is higher than that in a rest of the high-permittivity thin film.
Claim 2
Dependent Claim 33 words
A high-permittivity thin film essentially consisting of strontium titanate (SrTiO 3 ) comprising a surface layer where concentration of titanium atoms is higher than that in a rest of the high-permittivity thin film.
Claim 3
Dependent Claim 36 words
The high-permittivity thin film according to claim 1, wherein at a room temperature, relative permittivity of the high-permittivity thin film is higher than 100 and a leakage current is less than 1×10 -6 A/cm 2 .
Claim 4
Dependent Claim 18 words
The high-permittivity thin film according to claim 1, wherein the surface layer is thinner than 30 nm thick.
Claim 5
Dependent Claim 29 words
The high-permittivity thin film according to claim 1, wherein the high-permittivity thin film is thicker than 100 nm thick, when the surface layer is thicker than 10 nm thick.
Claim 6
Dependent Claim 92 words
A semiconductor device comprising: a semiconductor substrate where a semiconductor integrated circuit is formed; a capacitor formed on an insulated surface of the semiconductor substrate, the capacitor consisting of a pair of electrodes and a high-permittivity thin film between the electrodes, wherein the high-permittivity thin film essentially consists of strontium titanate (SrTiO 3 ) having a surface layer where concentration of titanium atoms is higher than that in a rest of the high-permittivity thin film; and an interconnection layer which operatively connects between one of the electrodes and the semiconductor integrated circuit.
Claim 7
Dependent Claim 92 words
A semiconductor device comprising: a semiconductor substrate where a semiconductor integrated circuit is formed; a capacitor formed on an insulated surface of the semiconductor substrate, the capacitor consisting of a pair of electrodes and a high-permittivity thin film between the electrodes, wherein the high-permittivity thin film essentially consists of strontium titanate (SrTiO 3 ) having a surface layer where concentration of titanium atoms is higher than that in a rest of the high-permittivity thin film; and an interconnection layer which operatively connects between one of the electrodes and the semiconductor integrated circuit.
Claim 8
Dependent Claim 75 words
The semiconductor device according to claim 5, wherein one of the electrodes is a laminating layer comprising of a platinum layer formed on a titanium layer which is formed on the insulated surface of the semiconductor substrate, the platinum layer adheres to the surface layer of the high-permittivity thin film, and another of the electrodes is a patterned layer of titanium nitride or titanium tungsten formed on the opposite surface of the high-permittivity thin film.

References Cited (Backward Citations)

US5005102A Cited
US5142437A Cited
US5332684A Cited
US5218512A Cited
US5216572A Cited
US5781404A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-03-21 2003-09-20 2004-03-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-03-21 2007-09-20 2008-03-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-03-21 2011-09-20 2012-03-21 $7700.00 Window Closed / Lapsed

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