Scalability of TiN/HfAlO/TiN MIM DRAM capacitor to 0.7-nm-EOT and beyond

We have proposed guiding principle of material selection of electrode/dielectric combination for MIM DRAM capacitors by theoretically taking the tunneling barrier height into account. Accordingly, we found that phase-controlled HfO
₂
(HfAlO) with TiN electrode is promising. TiN/HfAlO/TiN MIM capacitors with an ultra-thin Al
₂
O
₃
on the bottom TiN electrode were fabricated and an EOT of 0.7 nm with a leakage current of 80 nA/cm
²
was successfully achieved.