LEAKAGE CURRENT COMPARISON BETWEEN ULTRA-THIN TA2O5 FILMS AND CONVENTIONAL GATE DIELECTRICS

Capacitors with ultra-thin (6.0-12.0 mm) CVD Ta2O5 him were fabricated on lightly doped Si substrates and their leakage current (I-g-V-g,) a nd capacitance (C-V) characteristics were studied. For the first time, samples with stack equivalent oxide thickness around 2.0 nm were comp ared with ultra-thin silicon dioxide and silicon oxynitride. The Ta2O5 samples showed remarkably lower leakage current, which not only verif ied 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.