Simultaneously formed storage node contact and metal contact cell (SSMC) for 1 Gb DRAM and beyond

Simultaneously formed Storage node contact and Metal contact Cell (SSMC) was investigated and developed with 0.18 /spl mu/m advanced KrF lithography as a promising candidate for the cell structure of 1 Gb DRAM and beyond, such as 4 Gb and 16 Gb DRAMs. SSMC can provide fast and reliable memory cell operation by reducing parasitic resistance between memory cell storage node and access transistor. Also SSMC can reduce the processing steps compared to the conventional COB (Capacitor Over Bit line) cell by forming storage node contact holes and metal contact hole at the same time. Furthermore, it is found that SSMC has many other advantages in terms of process margin, and wide application, for example in EML (embedded memory logic). Thus, SSMC is a promising cell structure for 1 Gb DRAM and beyond.