Method of manufacturing a flash memory device with an antidiffusion region between well regions

摘要

There is disclosed a method of manufacturing a flash memory device. In order to solve the problems that a break down voltage between wells is reduced and an insulating characteristic between the wells is lowered due to degraded barrier characteristic between the wells, in a flash memory device employing a triple well structure, the present invention forms an anti-diffusion region for preventing diffusion of dopants between a P-well region and a N-well region by nitrogen ion implantation, thus improving the electrical characteristic of the device.