SEMICONDUCTOR STORAGE DEVICE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a highly reliable semiconductor storage device having a long refreshing time. SOLUTION: In a DRAM memory cell 16 in which a MOS transistor 2 and a storage capacitor 3 are formed on a silicon semiconductor substrate 1, the joining depth xj of a source-drain diffusion layer 4a below a storage node electrode 10 is adjusted to >=0.1μm. In order to adjust the depth xj in such a way, the source-drain diffusion layer 4a is formed by implanting phosphorus ions into the layer 4a with implanting energy of >=80keV.