Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device comprising:

• forming a contact hole opening an active region over a semiconductor substrate;
• forming a plug material in a lower portion of the contact hole;
• forming a first bit-line conductive material burying the contact hole over the plug material;
• forming a second bit-line conductive material over an entire surface including the first bit-line conductive material;
• forming a mask pattern over the second bit-line conductive layer;
• and
• etching the second bit-line conductive layer, the first bit-line conductive layer, and the plug material using the mask pattern as an etch mask, thereby forming a bit line contact plug and a bit line.

A semiconductor device comprising:

• a bit line contact hole extended from a first level to a second level;
• a bit line contact plug having a top surface at a third level provided between the first level and the second level;
• and
• a first bit line conductive layer having a top surface at a second level.

A method for manufacturing a semiconductor device comprising:

• forming a bit line contact hole to expose a substrate in a cell region from a first level to a second level;
• forming a bit line contact plug having a top surface at a third level provided between the first level and the second level in the bit line contact hole;
• and
• forming a first bit line conductive layer having a top surface at a second level over the bit line contact plug.