Semiconductor device and method of manufacturing thereof

A method of fabricating a semiconductor device comprising the steps of:

• forming a logic Circuit area including interconnection wirings connected to bit line driving transistors on a semiconductor substrate;
• forming a first layer intermediate insulating film on the entire surface for exposing the upper side of the interconnection wirings;
• forming bit lines electrically connected the interconnection wirings on the first layer intermediate insulating film;
• forming a second layer intermediate insulating film on the entire surface after forming the bit lines for exposing the a part of the bit lines;
• defining a cell forming area by selectively patterning the second layer intermediate insulating film;
• forming a silicon film on a part of the defined cell forming area, the silicon film is connected to the bit lines;
• forming a gate insulating film and a gate electrode on the silicon film;
• forming a source electrode and a drain electrode on the silicon film situated under the both sides of the gate electrode;
• forming a lower electrode for a capacitor on the entire surface to expose the source electrode;
• and
• forming a dielectric film and an upper electrode on the lower electrode.