Semiconductor storage device and method for fabricating the same

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

• forming a first conductor pattern over a semiconductor substrate;
• forming a first insulation film covering the first conductor pattern;
• forming over the first insulation film a second insulation film having etching characteristics different from those of the first insulation film;
• polishing the second insulation film;
• forming over the second insulation film a third insulation film having etching characteristics different from those of the second insulation film;
• forming over the third insulation film a fourth insulation film having etching characteristics different from those of the third insulation film;
• forming a hole in the fourth insulation film, the third insulation film, the second insulation film and the first insulation film;
• and
• forming a second conductor in the opening.

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

• forming a first conductor over a semiconductor substrate;
• forming a first insulation film covering the first conductor;
• forming over the first insulation film a second insulation film having etching characteristics different from those of the first insulation film;
• polishing the second insulation film;
• forming over the second insulation film a third insulation film;
• forming over the third insulation film a fourth insulation film;
• forming a hole exposing a second conductor in the fourth insulation film, the third insulation film and the second insulation film;
• and
• forming a third conductor in the hole.

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

• forming an impurity doped region in a semiconductor substrate;
• forming a first conductor over the semiconductor substrate;
• forming a first insulation film covering the first conductor;
• forming over the first insulation film a second insulation film having etching characteristics different from those of the first insulation film;
• polishing the second insulation film;
• forming over the second insulation film a third insulation film;
• forming over the third insulation film a fourth insulation film;
• forming a hole exposing the impurity doped region in the fourth insulation film, the third insulation film and the second insulation film;
• and
• forming a second conductor in the hole.