Method of manufacturing a semiconductor device

A method of manufacturing a semiconductor device, comprising the steps of:

• forming a word line on a semiconductor substrate;
• forming a word line/substrate etch stopper on the semiconductor substrate including the word line;
• forming a first interlayer insulating film on the entire structure including the word line/substrate etch stopper;
• forming a bit line on the first interlayer insulating film;
• forming a bit line etch stopper on the bit line;
• forming a second interlayer insulating film on the entire structure including the bit line etch stopper;
• forming a capacitor on the second interlayer insulating film;
• forming a capacitor etch stopper on the capacitor;
• forming a third interlayer insulating film on the entire structure including the capacitor etch stopper;
• forming a photoresist pattern for forming contact holes on the third interlayer insulating film;
• etching the interlayer insulating films by means of a first plasma dry etch process using the photoresist pattern as an etch mask to form the contact holes forming the bottom of each of the etch stoppers;
• and
• removing each of the etch stoppers exposed at the bottoms of the contact holes by means of a second plasma dry etch process to complete the contact holes.