Atomic layer-deposited LaAlO3 films for gate dielectrics

摘要

A dielectric film containing LaAlO₃ and method of fabricating a dielectric film contained LaAlO₃ produce a reliable gate dielectric having a thinner equivalent oxide thickness than attainable using SiO₂. The LaAlO₃ gate dielectrics formed are thermodynamically stable such that these gate dielectrics will have minimal reactions with a silicon substrate or other structures during processing. A LaAlO₃ gate dielectric is formed by atomic layer deposition employing a lanthanum sequence and an aluminum sequence. A lanthanum sequence uses La(thd)₃ (thd=2,2,6,6-tetramethyl-3,5-heptanedione) and ozone. An aluminum sequence uses either trimethylaluminum, Al(CH₃)₃, or DMEAA, an adduct of alane (AlH₃) and dimethylethylamine [N(CH₃)₂(C₂H₅)], with distilled water vapor.