Patent ID: 8354701

Claim:
A ferroelectric memory device, comprising: a semiconductor substrate; a field effect transistor formed on said semiconductor substrate, said field effect transistor including first and second diffusion regions; an interlayer insulation film formed on said semiconductor substrate so as to cover said field effect transistor; a conductive plug formed in said interlayer insulation film in contact with said first diffusion region; and a ferroelectric capacitor formed over said interlayer insulation in contact with said conductive plug, said ferroelectric capacitor comprising a ferroelectric film and an upper and a lower electrode sandwiching said ferroelectric film respectively from above and below, said lower electrode being connected electrically to said conductive plug, a silicon oxide nitride layer containing carbon and hydrogen being provided directly on said conductive plug and interposed between said the conductive plug and said lower electrode, a layer containing nitrogen being interposed between said silicon oxide nitride layer and said lower electrode, a self-aligned layer being interposed between said layer containing nitrogen and said lower electrode.