A memory device, such as a flash EEPROM, has zero birds' beaks and vertically overlapping gates to facilitate high cell density in the EEPROM's core. During fabrication, a layer of field oxide is formed over the core. The active regions are exposed by etching through the layer of field oxide to form...http://www.google.com/patents/US5661055?utm_source=gb-gplus-sharePatent US5661055 - Method of making nonvolatile memory cell with vertical gate overlap and zero birds' beaks
