Stress-induced leakage current comparison of giga-bit scale DRAM capacitors with OCS (one-cylinder-storage) node

Leakage current characteristics of capacitors for gigabit scale DRAMs (Dynamic Random Access Memory), where low leakage current is required to meet the specification for the data retention time, have been studied. Rugged-silicon technology, used to increase the surface of the storage nodes, causes large leakage current because the trap density of the dielectric on the rugged-Si is larger than that of the capacitors without rugged-Si. In-situ plasma phosphorus doping and nitridation of the storage node in a single wafer process chamber is an effective method to reduce the leakage current.