Low Equivalent Oxide Thickness TiO2 Based Capacitors for DRAM Application

Abstract

Properties of TiO2 based DRAM capacitors with equivalent oxide thickness of 0.5 nm are described. It is shown, that dielectric constant values more than 100 can be obtained in these structures for the TiO2 films with the thickness down to 10 nm. Leakage current density below 10-7 A/cm2 at 0.8 V can be obtained after post-deposition processing for the films with the thickness of 16 nm (EOT ≈ 0.5 nm). Al doping of the TiO2 films decreases dielectric constant, but improves leakage current density. Al-doped TiO2 films with the thickness of 10 nm (EOT = 0.46 nm) exhibit leakage current density below 10-7 A/cm at 0.8 V.