Method for forming storage node contact plug of DRAM (dynamic random access memory)

A method for fabricating a semiconductor device, comprising:

• forming one or more insulating layers on a semiconductor substrate having a buried contact plug;
• forming a photoresist pattern on a top surface of the insulating layers;
• etching the insulating layers, using the photoresist pattern as a mask, to form a first contact opening;
• etching the insulating layers down to the buried contact plug to form a second contact opening on the buried contact plug;
• subsequently, forming a second photoresist pattern on a top surface of the insulating layers and in the first contact opening;
• etching at least one insulating layer, using the second photoresist pattern as a mask, to form a pattern for a bit line that intersects the first contact opening;
• filling the first and second contact openings simultaneously with a conductive material to form a portion of a bit line in the first contact opening and a conductive plug in the second contact opening;
• forming an additional insulating layer on a top surface of the semiconductor substrate;
• and
• etching the additional insulating layer down to the conductive material to form a contact opening on the conductive material for formation of a storage node.