| 摘要 |
PROBLEM TO BE SOLVED: To reduce the bit line capacity of a DRAM reduced in memory size. SOLUTION: A sidewall insulating film of a gate electrode 7 (word line WL) is composed of a sidewall insulating film 10 made of silicon nitride and a sidewall insulating film 11 made of silicon oxide having a smaller relative permittivity. The capacity of a bit line formed on the gate electrode 7 (word line WL) with respect to the word line is reduced. Further, the upper end of the side wall insulating film 11 made of silicon oxide is set lower than the upper surface of a cap insulating film 9. Thus, an upper diameter of a plug 14, which is placed into a space (contact holes 12 and 13) of the gate electrode 7 (word line WL), is set larger than a diameter of the bottom to obtain a contact area between the contact hole 13 and a through hole formed thereon. |
