METHOD FOR MANUFACTURING FLASH MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a flash memory device is to increase the number of hot carriers by quickly producing a pinch-off phenomenon happened in an overlapped region of a gate and a drain, thereby improving a programing characteristic of a flash memory cell. CONSTITUTION: A source region is formed on a substrate through a source ion implantation process. A high voltage NMOS(metal oxide semiconductor) transistor region is carried out through a DDD(drain diffusion) ion implantation process. A cell region and a high voltage PMOS transistor region are simultaneously exposed, and are carried out through the DDD ion implantation process to form the first source ion implantation region(206) and the first drain ion implantation region(207). The first p-ion implantation region(208) and the second p-ion implantation region(209) are formed in the high voltage PMOS transistor region. A common source line is formed by a self-align source etching, ion implantation and annealing process.