Leakage Current Comparison Between Ultra-Thin Ta2O5 Films and Conventional Gate Dielectrics

Capacitors with ultra-thin (6.0–12.0 nm) CVD Ta2O5 film were fabricated on lightly doped Si substrates and their leakage current (Ig–Vg) and capacitance (C–V ) characteristics were studied. For the first time, samples with stack equivalent oxide thickness around 2.0 nm were compared with ultra-thin silicon dioxide and silicon oxynitride. The Ta2O5 samples showed remarkably lower leakage current, which not only verified the advantages of ultra-thin Ta2O5 as dielectrics for high density DRAM’s, but also suggested the possibility of its application as the gate dielectric material in MOSFET’s.