Method for fabricating semiconductor device

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

• (1) forming an interlayer insulating film, an etch stopper film, and a PE-TEOS film in succession on a semiconductor substrate having a wordline and a bitline formed thereon;
• (2) forming a storage electrode contact mask as an etch mask and etching the PE-TEOS film, the etch stopper film, and the interlayer insulating film to form a storage electrode contact hole;
• (3) forming a polysilicon layer;
• (4) etching back the polysilicon layer to form both a contact plug and a recess of predetermined depth above the contact plug in the storage electrode contact hole;
• (5) forming a core oxide film pattern to expose a region in which a storage electrode will be formed;
• and,
• (6) forming a cylindrical storage electrode that contacts the storage electrode contact plug through the recess.

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

• (1) forming a first interlayer insulating film, an etch stopper film, and a PE-TEOS film on a semiconductor substrate having a wordline formed thereon;
• (2) by using a bitline contact mask as an etch mask, etching the PE-TEOS film, the etch stopper film, and the first interlayer insulating film, to form a first bitline contact hole;
• (3) forming a first polysilicon layer on an entire surface;
• (4) etching back the first polysilicon layer to form a first bitline contact plug, wherein a portion above the first bitline contact plug is etched to remove a predetermined thickness of the first polysilicon layer to form recess that is wider than the first bitline contact hole;
• (5) forming a second interlayer insulating film having a second bitline contact hole exposing the first bitline contact plug;
• (6) forming and etching back a second polysilicon layer, to form a second bitline contact plug in contact with the first bitline contact plug;
• and,
• (7) forming a bitline in contact with the second bitline contact plug.