Ferroelectric memory element
AssigneesYasuo Tarui, Nippon Precision Circuits Inc.
InventorsYasuo Tarui, Kazuo Sakamaki
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Abstract
Ferroelectric memory element having an MFIS structure including a silicon semiconductor substrate and an insulating film arranged above the silicon semiconductor substrate. The insulating film includes a low dielectric constant layer restraining film and a mutual diffusion preventive film so that an unnecessary, low dielectric constant layer is prevented from forming between the semiconductor substrate and the insulating film. A ferroelectric film is arranged on the insulating film. The low dielectric constant layer restraining film is thinner than the ferroelectric film.
Claims9
A ferroelectric memory element, comprising:
- a silicon semiconductor substrate;
- an insulating film arranged above said substrate;
- and
- a ferroelectric film arranged above said insulating film,
- said insulating film including a low dielectric constant layer restraining film and a mutual diffusion preventive film, said low dielectric constant layer restraining film being thinner than said ferroelectric film,
- said low dielectric constant layer restraining film being a silicon oxynitride film or a silicon nitride film,
- said mutual diffusion preventive film being a cerium oxide (CeO2) film, and
- said ferroelectric film being a film of SrBi2Ta2O9.
A ferroelectric memory element, comprising:
- a silicon semiconductor substrate;
- an insulating film laminated onto said substrate;
- and
- a ferroelectric film laminated onto said insulating film,
- said insulating film including a low dielectric constant layer restraining film in contact with said substrate and a mutual diffusion preventive film, said low dielectric constant layer restraining film having a thickness of 1 nm to 2 nm,
- said low dielectric constant layer restraining film being an insulating film mainly comprising a silicon nitride film.
A ferroelectric memory element, comprising:
- a silicon semiconductor substrate;
- an insulating film laminated onto said substrate;
- and
- a ferroelectric film laminated onto said insulating film,
- said insulating film including a low dielectric constant layer restraining film in contact with said substrate and a mutual diffusion preventive film,
- said low dielectric constant layer restraining film having a thickness of 1 nm to 2 nm,
- said low dielectric constant layer restraining film being a silicon oxynitride film,
- said mutual diffusion preventive film being a cerium oxide (CeO2) film and
- said ferroelectric film being a film of SrBi2Ta2O9.
A ferroelectric memory element, comprising:
- a silicon semiconductor substrate;
- an insulating film laminated onto said substrate;
- and
- a ferroelectric film laminated onto said insulating film,
- said insulating film including a low dielectric constant layer restraining film in contact with said substrate and a mutual diffusion preventive film,
- said low dielectric constant layer restraining film having a thickness of 1 nm to 2 nm,
- said low dielectric constant layer restraining film being a silicon nitride film,
- said mutual diffusion preventive film being a cerium oxide (CeO2) film and
- said ferroelectric film being a film of SrBi2Ta2O9.
Dependencies are inferred from the claim text.