SEMICONDUCTOR DEVICE HAVING DIFFERENT NON-VOLATILE MEMORIES HAVING NANOCRYSTALS OF DIFFERING DENSITIES AND METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a semiconductor device having nanocrystals.SOLUTION: A method for forming a semiconductor device includes the steps of: forming a first plurality of nanocrystals over a surface of a substrate having a first region and a second region, where the first plurality of nanocrystals are formed in the first region and the second region and has a first density; and, after forming the first plurality of nanocrystals, forming a second plurality of nanocrystals over the surface of the substrate in the second region and not in the first region, where the first plurality of nanocrystals together with the second plurality of nanocrystals in the second region result in a second density greater than the first density.