Stacked capacitor-type semiconductor storage device and manufacturing method thereof

A semiconductor device comprising:

• a plurality of MOS transistors each having a gate electrode and source/drain regions, the MOS transistors being formed on a surface region of a semiconductor substrate;
• bit lines connected to one of the source/drain regions of the MOS transistors, the bit lines being located so as to intersect perpendicularly to a word line connected to the gate electrode;
• capacitors formed above the bit lines;
• a first insulating film covering the MOS transistors;
• a second insulating film formed on each of the bit lines;
• a third insulating film formed on the first insulating film and between the bit lines;
• contact holes for storage node contacts connected between the other of the source/drain regions and a storage node electrode of the capacitors, formed through the third insulating film and the first insulating film;
• a fourth insulating film formed in the contact holes and on at least a side wall of the bit lines and a side wall of the first insulating film;
• and
• conductive plugs filling up the contact holes, the storage node electrode of each of the capacitors being electrically connected to the other of the source/drain regions of the MOS transistors by each of the conductive plugs.

A semiconductor device comprising:

• a plurality of MOS transistors each having a gate electrode and source/drain regions, the MOS transistors being formed on a surface region of a semiconductor substrate;
• bit lines connected to one of the source/drain regions of the MOS transistors, the bit lines being located so as to intersect perpendicularly to a word line connected to the gate electrode;
• capacitors formed above the bit lines;
• a first insulating film covering the MOS transistors, the bit lines being formed on the first insulating film;
• a second insulating film formed on each of the bit lines;
• a third insulating film formed on at least the first insulating film;
• contact holes formed through the third insulating film and the first insulating film, and connected to a storage node electrode of each of the capacitors;
• a fourth insulating film formed on a side wall of the bit lines and a side wall of the first insulating film;
• and
• conductive plugs filling up the contact holes, the storage node electrode of each of the capacitors being electrically connected to the other of the source/drain regions of the MOS transistors by each of the conductive plugs.

A semiconductor device comprising:

• a semiconductor substrate;
• an element separating insulating film formed in the semiconductor substrate, the element separating insulating film separating an element region;
• MOS transistors, formed in the element region, each of the MOS transistors having a gate insulating film, a gate electrode connected to a word line and source/drain regions;
• a first insulating film covering the element separating insulating film and the MOS transistors;
• first contact holes formed in the first insulating film, and reaching one of the source/drain regions of the MOS transistors;
• second contact holes formed in the first insulating film, and reaching the other of the source/drain region of the MOS transistors;
• first conductive plugs filling up the first contact holes;
• second conductive plugs filling up the second contact holes;
• a second insulating film covering the first insulating film and the first and second conductive plugs;
• bit line contacts formed in the second insulating film, and reaching the first conductive plugs;
• bit lines formed on the second insulating film and the bit line contacts, a lower part of each of the bit lines being composed of a conductive film and an upper part being composed of a third insulating film;
• a fourth insulating film formed on the second insulating film and between the bit lines;
• storage node contact holes for storage node contacts of the capacitors, formed through the fourth insulating film and the second insulating film;
• a fifth insulating film formed in the storage node contact holes and on at least a side wall of the conductive film of the bit lines and a side wall of the second insulating film;
• and
• capacitors, each of the capacitors having a storage node electrode, a capacitor insulating film formed on the storage node electrode, and a plate electrode formed on the capacitor insulating film, wherein the storage node electrode is connected to the second conductive plugs by the storage node contact holes.