Thin film capacitor
First Claim
1. A capacitor comprising a multilayer structure between two electrodes, the multilayer structure comprising:
- a first layer and a second layer of a first dielectric material having a first dielectric constant;
the first layer having an internal structure affecting formation of a crystalline structure of the second layer;
the crystalline structure of the second layer affecting formation of a perovskite crystalline structure of a ferroelectric layer deposited on the second layer;
the ferroelectric layer having a second dielectric constant higher than the first dielectric constant; and
an amorphous layer serving to limit leakage current in the capacitor by terminating grain boundaries in the ferroelectric layer.
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Accused Products
Abstract
Ferroelectric PbZrx T1-x O3 (PZT) thin films are deposited on Pt coated Si substrates by using RF magnetron sputtering. A method for obtaining desirable stoichiometric PZT, the desired ferroelectric perovskite phase, and better dielectric properties using a PZT target with Pb/(Zr+Ti) ratio of 1.2 and depositing at 350° C., followed by thermal treatment at 620° C. for 30 min is disclosed. The structural and electrical properties of the PZT layer were further improved by a method of fabricating a novel multi-layer structure which combined the PZT thin film with nanolayers of BaTiO3. The method and device of the present invention provided reduced leakage current density while maintaining high relative effective dielectric constants.
131 Citations
12 Claims
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1. A capacitor comprising a multilayer structure between two electrodes, the multilayer structure comprising:
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a first layer and a second layer of a first dielectric material having a first dielectric constant; the first layer having an internal structure affecting formation of a crystalline structure of the second layer; the crystalline structure of the second layer affecting formation of a perovskite crystalline structure of a ferroelectric layer deposited on the second layer; the ferroelectric layer having a second dielectric constant higher than the first dielectric constant; and an amorphous layer serving to limit leakage current in the capacitor by terminating grain boundaries in the ferroelectric layer. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A multilayer structure disposed between a first electrode and a second electrode, the multilayer structure comprising:
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a microcrystalline layer of a first dielectric material deposited on the first electrode; a polycrystalline layer of a first dielectric material deposited on the microcrystalline layer; a layer of a second dielectric material deposited on the polycrystalline layer, the second dielectric material having a dielectric constant higher than that of the first dielectric material and having a crystalline structure substantially corresponding to a perovskite phase; and an amorphous layer of the first dielectric material deposited between the second electrode and the layer of the second dielectric material. - View Dependent Claims (9, 10, 11, 12)
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Specification