Ta/sub 2/O/sub 5//TiO/sub 2/ Composite Films For High Density DRAM Capacitors

As DRAM density is increased to 256 megabits and beyond, the Ta2O5 (Er~25) has attracted more attention as a dielectric film for DRAM capacitors.[1?2] The use of Ta2O5 is, however, expected to be limited to only one generation of DRAM, because its scaling limit is about 2.5nm.[3]