Semiconductor device having a capacitor and a fabrication method thereof

A method of fabricating a semiconductor device having a capacitor, comprising:

• forming on a semiconductor substrate a first insulating layer having a first contact hole exposing the semiconductor substrate;
• forming a contact plug in the first contact hole;
• forming a buffer conductive layer pattern on the contact plug and the first insulating layer;
• forming a sacrificial layer pattern on the buffer conductive layer pattern;
• forming an etching stopping layer on the sacrificial layer pattern;
• forming a second insulating layer on the etching stopping layer;
• forming a second contact hole by etching portions of the second insulating layer and the etching stopping layer to expose a portion of the sacrificial layer pattern;
• removing a portion of the sacrificial layer pattern to expose the buffer conductive layer pattern and form a gap between the etching stopping layer and the buffer conductive layer pattern;
• and
• forming a capacitor lower electrode in the second contact hole and the gap.