Both a non-volatile memory (NVM) and a dynamic nanocrystal memory (DNM) are integrated on a semiconductor substrate. Control gates and control dielectrics with embedded nanocrystals or discrete storage elements are formed over differing thicknesses of tunnel dielectrics to form the two memories. Source...http://www.google.de/patents/US6790727?utm_source=gb-gplus-sharePatent US6790727 - Integration of two memory types on the same integrated circuit
