Method of manufacturing a semiconductor storage device

摘要: A method of manufacturing a semiconductor storage device comprises the steps forming source region and drain in surface substrate first conductivity type manner to be spaced from each other, said regions having second type; an insulating film on between regions; implanting ions electrically conductive element into film, thus form floating gate; leading out electrodes regions, respectively. By varying implantation energy dose rate step, amount charges accumulated gate can controlled.