MANUFACTURING METHOD OF MEMORY DEVICE IMPROVED ERASING PROPERTY

摘要

A method of manufacturing a memory device is provided to secure the stability of erase characteristics by using a blocking oxide layer with a negative fixed oxide charge. A tunneling oxide layer(22), a charge storing layer(23) and a blocking oxide layer(24) are sequentially formed on a semiconductor substrate(20). A heat treatment is performed on the resultant structure under O2, RuO or NH3 gas conditions in order to obtain a negative fixed oxide charge from the blocking oxide layer. A gate electrode layer is formed on the blocking oxide layer. The substrate is partially exposed to the outside by etching selectively the tunneling oxide layer, the charge storing layer, the blocking oxide layer and the gate electrode layer. First and second doped regions are formed in the exposed substrate by using an ion implantation.