METHOD FOR FORMING SONOS MEMORY CELL

摘要

PURPOSE: A method for forming an SONOS(Silicon Oxide Nitride Oxide Silicon) memory cell is provided to be capable of increasing the barrier potential for the electrons trapped at a trap site and improving information storing characteristics. CONSTITUTION: A tunnel oxide layer(22) is formed on a semiconductor substrate(20). A silicon nitride layer is formed on the tunnel oxide layer. A heat treatment is carried out on the resultant structure under hydrogen added oxygen atmosphere for partially oxidizing the silicon nitride layer into a silicon oxide nitride layer. A gate electrode(36) is formed on the silicon oxide nitride layer. Preferably, the tunnel oxide layer is formed by carrying out one selected from a group consisting of a thermal oxidation process, a CVD(Chemical Vapor Deposition), and a plasma oxidation. Preferably, the silicon nitride layer is formed by carrying out one selected from a group consisting of the CVD and an ALD(Atomic Layer Deposition).