Electricity: electrical systems and devices – Electrostatic capacitors – Fixed capacitor
Patent
1995-06-07
1998-07-14
Ledynh, Bot L.
Electricity: electrical systems and devices
Electrostatic capacitors
Fixed capacitor
3613214, 361305, 257295, H01G 410
Patent
active
057814040
ABSTRACT:
A preferred embodiment of this invention comprises a first thin dielectric buffer layer of a first leakage-current-density material (e.g. strontium titanate 32) with a first moderate-dielectric-constant, a high-dielectric-constant layer of a second leakage-current-density material (e.g. barium strontium titanate 34) overlaying the first thin dielectric buffer layer, and a second thin dielectric buffer layer of a third leakage-current-density material (e.g. strontium titanate 36) with a second moderate-dielectric-constant overlaying the high-dielectric-constant layer, wherein the first and third leakage-current-density materials have substantially lower leakage-current-densities than the second leakage-current-density material. The first and second thin moderate-dielectric-constant buffer layers (e.g. strontium titanate 32, 36) substantially limit the leakage-current-density of the structure, with only modest degradation of the dielectric constant of the structure. The possibly lower dielectric constant of the structure is generally compensated for by the reduced leakage current of the structure. The additional layers generally require only minor modifications of existing processes, since the same processes that are used for the high-dielectric-constant oxide can generally be used for the low leakage-current-density dielectric. These structures may also be used for multilayer capacitors and other thin-film ferroelectric devices such as pyroelectric materials, non-volatile memories, thin-film piezoelectric and thin-film electro-optic oxides.
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Beratan Howard Roy
Summerfelt Scott R.
Carlson Brian A.
Donaldson Richard L.
Kesterson James C.
Ledynh Bot L.
Texas Instruments Incorporated
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