Method for fabricating contact pad for semiconductor device

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

• forming device isolation layers in device isolation regions in a semiconductor substrate that includes a cell region and a peripheral circuit region by STI (shallow trench isolation), to define active regions;
• forming wordlines crossing the active regions in a short axis direction;
• forming a first insulating layer on an entire surface that has the wordlines formed thereon;
• forming a first photomask layer on the peripheral circuit region, and etching the photomask layer back to form gate sidewalls at both sides of the wordlines in the cell region;
• forming a second insulating layer and a third insulating layer;
• planarizing the third insulating layer;
• forming a second photomask layer on the third insulating layer excluding a bitline contact portion, an extension growth region in contact with the bitline contact portion, and a storage contact portion, and selectively etching an exposed portion of the third insulating layer, to form epitaxial growth blocking layer;
• and
• using the epitaxial growth blocking layer to isotropically grow a contact pad.