A non-volatile memory cell structure that is capable of holding two data bits. The structure includes a trench in a substrate with two sides of the trench being lined with a trapping material. The trench is filled with an oxide dielectric material and a control gate is formed over the oxide-filled trench....http://www.google.fr/patents/US6977412?utm_source=gb-gplus-shareBrevet US6977412 - Trench corner effect bidirectional flash memory cell
