Method for forming contact plug of semiconductor device

A method for forming a contact plug of a semiconductor device, comprising the steps of:

• providing a substrate providing a plurality of conductive patterns, wherein the substrate has a first area and a second area lower than the first area and step difference exists between the first area and the second area;
• forming an insulating layer on the substrate;
• forming a plurality of contact hole by selectively etching the insulating layer;
• forming a conductive layer on the insulating layer and in the contact hole;
• removing the step difference between the first area and the second area by selectively removing the conductive layer in the first area;
• and
• forming an isolated plug in each contact hole by removing the conductive layer until a surface of the conductive layer is exposed.

A method for forming a contact plug of a semiconductor device, comprising the steps of:

• providing a substrate providing a plurality of conductive patterns, wherein the substrate has a first area and a second area lower than the first area and step difference exists between the first area and the second area;
• forming an insulating layer on the substrate;
• removing the step difference between the first area and the second area by selectively removing the insulating layer in the first area;
• forming a plurality of contact hole by selectively etching the insulating layer;
• forming a conductive layer on the insulating layer and in the contact hole;
• and
• forming an isolated plug in each contact hole by removing the conductive layer until a surface of the conductive layer is exposed.