Device and manufacturing method for a ferroelectric memory

Claim 1

A method for manufacturing a ferroelectric memory device, comprising the steps of: forming a device isolation region in a area of a semiconductor substrate of a first conductivity type; sequentially depositing a yttrium oxide film, a ferroelectric film, and a conductive film over the surface of the semiconductor substrate; forming a mask pattern over the yttrium oxide film, ferroelectric film, and gate conductive film; forming a gate electrode, a ferroelectric gate film and a yttrium oxide gate film by etching the conductive film, the ferroelectric film and the yttrium oxide film, using the mask pattern as an etching mask; and forming a source/drain region by ion-implanting a second conductivity impurity into the semiconductor substrate.

Claim 2

A method for manufacturing a ferroelectric memory device, comprising the steps of: forming a device isolation region in a area of a semiconductor substrate of a first conductivity type; sequentially depositing a yttrium oxide film, a ferroelectric film, and a conductive film over the surface of the semiconductor substrate; forming a mask pattern over the yttrium oxide film, ferroelectric film, and gate conductive film; forming a gate electrode, a ferroelectric gate film and a yttrium oxide gate film by etching the conductive film, the ferroelectric film and the yttrium oxide film, using the mask pattern as an etching mask; and forming a source/drain region by ion-implanting a second conductivity impurity into the semiconductor substrate.

Claim 4

A method for manufacturing a ferroelectric memory device, comprising the steps of: forming a device isolation region in a area of a semiconductor substrate of a first conductivity type; sequentially depositing a yttrium oxide film, a ferroelectric film, a conductive film, and a mask layer; forming a mask pattern by patterning the mask layer; forming a gate comprising a gate electrode, a gate ferroelectric film, and a gate yttrium oxide film by etching the gate conductive film, the ferroelectric film, and the yttrium oxide film, using the mask pattern as an etching mask; ion-implanting a first impurity of a second conductivity type different from the first conductivity type and having a first concentration into the semiconductor substrate; forming a spacer over the gate and covering sidewalls of the gate by depositing a material layer over the semiconductor substrate and dry-etching the material layer; and forming a source/drain region by again ion-implanting a second impurity of the second conductivity type and having a second concentration into the semiconductor substrate, the second concentration being higher than the first concentration.

Claim 5

A method for manufacturing a ferroelectric memory device, comprising the steps of: forming a device isolation region in a area of a semiconductor substrate of a first conductivity type; sequentially depositing a yttrium oxide film, a ferroelectric film, a conductive film, and a mask layer; forming a mask pattern by patterning the mask layer; forming a gate comprising a gate electrode, a gate ferroelectric film, and a gate yttrium oxide film by etching the gate conductive film, the ferroelectric film, and the yttrium oxide film, using the mask pattern as an etching mask; ion-implanting a first impurity of a second conductivity type different from the first conductivity type and having a first concentration into the semiconductor substrate; forming a spacer over the gate and covering sidewalls of the gate by depositing a material layer over the semiconductor substrate and dry-etching the material layer; and forming a source/drain region by again ion-implanting a second impurity of the second conductivity type and having a second concentration into the semiconductor substrate, the second concentration being higher than the first concentration.