US4437139A
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US
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Laser annealed dielectric for dual dielectric capacitor
Assignee: International Business Machines Corp
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Filing: 1982-12-17
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Granted: 1984-03-13
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Expires: 2002-12-17
Abstract
Abstract A thin film capacitor having a high dielectric constant and low leakage current includes a dual dielectric structure. The dual dielectric comprises a leakage current blocking first dielectric layer and a high dielectric constant second dielectric layer. The high dielectric constant second dielectric layer is formed by laser annealing a ferroelectric forming titanate or zirconate into a ferroelectric. A leakage current blocking first dielectric layer may also serve as an antireflective coating for the titanate or zirconate layer so that better coupling of the laser energy to the titanate or zirconate layer is obtained.
Inventors
- 👤 James K. Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:32
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/20; H10; H10B; H10B53/00; H10D; H10D1/00; H10D1/60; H10D1/68; Y; Y10; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
70 words
A method of forming a capacitor on a substrate, comprising the steps of: depositing a bottom electrode on the substrate; depositing an amorphous thin film layer of a ferroelectric forming titanate or zirconate on said bottom electrode; depositing a leakage current preventing dielectric layer on said amorphous thin film layer; laser annealing said amorphous thin film layer to a crystalline ferroelectric; and depositing a top electrode on said dielectric layer.
Claim 2
Independent Claim
70 words
A method of forming a capacitor on a substrate, comprising the steps of: depositing a bottom electrode on the substrate; depositing an amorphous thin film layer of a ferroelectric forming titanate or zirconate on said bottom electrode; depositing a leakage current preventing dielectric layer on said amorphous thin film layer; laser annealing said amorphous thin film layer to a crystalline ferroelectric; and depositing a top electrode on said dielectric layer.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein said bottom electrode comprises a first layer of Zr, Hf or Ta and a second layer of Pt.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein said ferroelectric forming titanate or zirconate is PbTiO 3 , BaTiO 3 , CaTiO 3 , SrTiO 3 , PZT or PZLT.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein said leakage current preventing dielectric layer is SiO 2 or Si 3 N 4 .
Claim 6
Dependent Claim
41 words
The method of claim 1 wherein the leakage current preventing layer depositing step includes the steps of: depositing an SiO 2 layer on said amorphous thin film layer and depositing an Si 3 N 4 layer on said SiO 2 layer.
Claim 7
Dependent Claim
27 words
The method of claim 1 wherein said leakage current preventing dielectric layer is also an antireflective coating for coupling laser energy to said amorphous thin film layer.
Claim 8
Independent Claim
70 words
A method of forming a capacitor on a substrate, comprising the steps of: depositing a bottom electrode on the substrate; depositing an amorphous thin film layer of a ferroelectric forming titanate or zirconate on said bottom electrode; laser annealing said amorphous thin film layer to a crystalline ferroelectric; depositing a leakage current preventing dielectric layer on said amorphous thin film layer; and depositing a top electrode on said dielectric layer.
Claim 9
Independent Claim
70 words
A method of forming a capacitor on a substrate, comprising the steps of: depositing a bottom electrode on the substrate; depositing an amorphous thin film layer of a ferroelectric forming titanate or zirconate on said bottom electrode; laser annealing said amorphous thin film layer to a crystalline ferroelectric; depositing a leakage current preventing dielectric layer on said amorphous thin film layer; and depositing a top electrode on said dielectric layer.
Claim 10
Dependent Claim
24 words
The method of claim 7 wherein said bottom electrode comprises a first layer of Zr, Hf or Ta and a second layer of Pt.
Claim 11
Dependent Claim
28 words
The method of claim 7 wherein said ferroelectric forming titanate or zirconate is PbTiO 3 , BaTiO 3 , CaTiO 3 , SrTiO 3 , PZT or PZLT.
Claim 12
Dependent Claim
21 words
The method of claim 7 wherein said leakage current preventing dielectric layer is SiO 2 or Si 3 N 4 .
Claim 13
Dependent Claim
41 words
The method of claim 7 wherein the leakage current preventing layer depositing step includes the steps of: depositing an SiO 2 layer on said amorphous thin film layer and depositing an Si 3 N 4 layer on said SiO 2 layer.
Claim 14
Independent Claim
68 words
A method of forming a capacitor on a substrate, comprising the steps of: depositing a bottom electrode on the substrate; depositing a leakage current preventing dielectric layer on said bottom electrode; depositing an amorphous thin film layer of a ferroelectric forming titanate or zirconate on said bottom electrode; laser annealing said amorphous thin film layer to a crystalline ferroelectric; and depositing a top electrode on said dielectric layer.
Claim 15
Independent Claim
68 words
A method of forming a capacitor on a substrate, comprising the steps of: depositing a bottom electrode on the substrate; depositing a leakage current preventing dielectric layer on said bottom electrode; depositing an amorphous thin film layer of a ferroelectric forming titanate or zirconate on said bottom electrode; laser annealing said amorphous thin film layer to a crystalline ferroelectric; and depositing a top electrode on said dielectric layer.
Claim 16
Dependent Claim
24 words
The method of claim 12 wherein said bottom electrode comprises a first layer of Zr, Hf or Ta and a second layer of Pt.
Claim 17
Dependent Claim
28 words
The method of claim 12 wherein said ferroelectric forming titanate or zirconate is PbTiO 3 , BaTiO 3 , CaTiO 3 , SrTiO 3 , PZT or PZLT.
Claim 18
Dependent Claim
21 words
The method of claim 12 wherein said leakage current preventing dielectric layer is SiO 2 or Si 3 N 4 .
Claim 19
Dependent Claim
38 words
The method of claim 12 wherein said amorphous thin film depositing step is followed by the step of depositing an antireflective coating on said amorphous thin film layer for coupling laser energy to said amorphous thin film layer.
Claim 20
Dependent Claim
26 words
The method of claim 16 wherein said laser annealing step is followed by the step of removing said antireflective coating from said amorphous thin film layer.
Claim 21
Dependent Claim
72 words
A capacitor structure comprised of a dual dielectric between two electrodes wherein said dual dielectric comprises: a first leakage current preventing dielectric layer adjacent a first one of said electrodes; and a second dielectric layer between said first dielectric layer and a second one of said electrodes, said second dielectric layer being an amorphous thin film layer of a ferroelectric forming titanate or zirconate which is laser annealed to a crystalline ferroelectric.
Claim 22
Dependent Claim
72 words
A capacitor structure comprised of a dual dielectric between two electrodes wherein said dual dielectric comprises: a first leakage current preventing dielectric layer adjacent a first one of said electrodes; and a second dielectric layer between said first dielectric layer and a second one of said electrodes, said second dielectric layer being an amorphous thin film layer of a ferroelectric forming titanate or zirconate which is laser annealed to a crystalline ferroelectric.
Claim 23
Dependent Claim
24 words
The structure of claim 18 wherein said bottom electrode comprises a first layer of Zr, Hf or Ta and a second layer of Pt.
Claim 24
Dependent Claim
28 words
The structure of claim 18 wherein said ferroelectric forming titanate or zirconate is PbTiO 3 , BaTiO 3 , CaTiO 3 , SrTiO 3 , PZT or PZLT.
Claim 25
Dependent Claim
21 words
The structure of claim 18 wherein said leakage current preventing dielectric layer is SiO 2 or Si 3 N 4 .
Claim 26
Dependent Claim
29 words
The structure of claim 18 wherein said leakage current preventing dielectric layer is a dual layer structure comprising an SiO 2 layer and an Si 3 N 4 layer.
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