Challenges of Ta2O5 as High-k Dielectric for Nanoscale DRAMs

The present status, successes, challenges and future of Ta
₂
O
₅
, and mixed Ta
₂
O
₅
-based high-k layers as active component in storage capacitors of nanoscale DRAMs are discussed. The engineering of new Ta
₂
O
₅
-based dielectrics (doped Ta
₂
O
₅
and multicomponent high-k dielectrics) as well as of metal/high-k interface in MIM capacitor configuration are identified as critical factors for further reduction of EOT value below 1 nm