Method for making a capacitor having an electrode surface with a plurality of trenches formed therein

A method for making a capacitor, comprising the steps of:

• forming a first conductive layer on a major surface of a substrate;
• patterning said first conductive layer, to thereby form a first patterned layer;
• forming a first oxide film on said first patterned layer and exposed portions of said major surface of said substrate;
• forming a silicon nitride film on said first oxide film;
• oxidizing said silicon nitride film, to thereby form a second oxide film;
• wherein a plurality of pinholes are formed in said silicon nitride film during said oxidizing step, to thereby form a second patterned layer;
• removing said second oxide film and exposed portions of said first oxide film:
• etching said first conductive layer, using said second patterned layer as a mask, to thereby form a plurality of microscopic trenches in said first conductive layer;
• removing remaining portions of said first oxide film and said second patterned layer;
• and,
• forming a dielectric film on said first patterned layer;
• and,
• forming a second conductive layer on said dielectric film.