Semiconductor device having ferroelectric capacitor and method for manufacturing the same

A semiconductor device comprising:

• a first interlayer insulating film formed on a semiconductor substrate;
• a first lower electrode formed on said first interlayer insulating film;
• a pair of second lower electrodes formed on said first lower electrode separately from each other, each of said pair of second lower electrodes comprises a horizontal first portion and a second portion extending vertically from an end of the first portion, and a first recess portion is formed with the first and second portions;
• a pair of ferroelectric films formed so as to fill said first recess portions of said pair of second lower electrodes, each of said pair of ferroelectric films has a second recess portion;
• and
• a pair of upper electrodes formed so as to fill said second recess portions of said pair of ferroelectric films,
• wherein said first lower electrode, said pair of second lower electrodes, said pair of ferroelectric films, and said pair of upper electrode constitute a pair of ferroelectric capacitors,
• wherein each of the first and second recess portions is a U-shaped recess portion, and
• wherein the vertically extending second portion of each of the pair of second electrodes extends entirely vertically from the end of the first portion to a top surface of the pair of ferroelectric capacitors.

A semiconductor storage device comprising:

• a semiconductor substrate;
• a plurality of transistors formed on said semiconductor substrate;
• a first interlayer insulating film formed so as to cover said plurality of transistors;
• and
• a plurality of ferroelectric capacitors each composing a laminated structure of a lower electrode, a ferroelectric film, and an upper electrode sequentially formed on said first interlayer insulating film,
• wherein said plurality of ferroelectric capacitors constitute sets each comprising two of said ferroelectric capacitors, said lower electrode is shared by said one set of ferroelectric capacitors, said upper electrode is individually separated between said one set of ferroelectric capacitors, and a space between said upper electrodes of said one set of ferroelectric capacitors is smaller than a space between said upper electrodes of said one set of ferroelectric capacitors and said upper electrodes of an adjacent set of ferroelectric capacitors,
• wherein said one set of ferroelectric capacitors have peripheries thereof formed into inclined surfaces extending continuously from a top surface of said upper electrode to a bottom surface of said lower electrode and having no step, and said individual upper electrodes of said one set of ferroelectric capacitors are separated by a generally V-shaped groove.

A semiconductor storage device comprising:

• a semiconductor substrate;
• a plurality of transistors formed on said semiconductor substrate;
• a first interlayer insulating film formed so as to cover said plurality of transistors;
• and
• a plurality of ferroelectric capacitors each composing a laminated structure of a lower electrode, a ferroelectric film, and an upper electrode sequentially formed on said first interlayer insulating film,
• wherein said plurality of ferroelectric capacitors constitute sets each comprising two of said ferroelectric capacitors, said lower electrode is shared by said one set of ferroelectric capacitors, said upper electrode is individually separated between said one set of ferroelectric capacitors and has a space, said one set of ferroelectric capacitors have peripheries thereof formed into inclined surfaces extending continuously from a top surface of said upper electrode to a bottom surface of said lower electrode and having no step, and said individual upper electrodes in said one set of ferroelectric capacitors are separated by a generally V-shaped groove.