For obtaining improved writing characteristics, a reduced source resistance and an increased cell current of a ultraviolet-erasable type nonvolatile semiconductor memory device, a plurality of field oxide films with an asymmetrical pattern are provided which are arranged in rows and columns to define...http://www.google.es/patents/US5255219?utm_source=gb-gplus-sharePatente US5255219 - Ultraviolet-erasable type nonvolatile semiconductor memory device having asymmetrical field oxide structure
Ultraviolet-erasable type nonvolatile semiconductor memory device having ...
