Capacitor with hafnium, lanthanum and oxygen mixed dielectric and method for fabricating the same

摘要

Disclosed is a capacitor with a dielectric layer having a low equivalent oxide thickness compared to a HfO₂ layer and capable of decreasing a level of a leakage current incidence and a method for fabricating the same. Particularly, the capacitor includes: a bottom electrode; a Hf_1-xLa_xO layer on the bottom electrode; and a top electrode on the Hf_1-xLa_xO layer, wherein x is an integer. The method includes the steps of: forming at least one bottom electrode being made of polysilicon doped with impurities; nitriding a surface of the bottom electrode; depositing the amorphous Hf_1-xLa_xO layer on the nitrided surface of the bottom electrode; performing a thermal process for crystallizing the amorphous Hf_1-xLa_xO layer and removing impurities existed within the Hf_1-xLa_xO layer; nitriding a surface of the crystallized Hf_1-xLa_xO layer; and forming the top electrode being made of polysilicon doped with impurities on the nitrided surface of the crystallized Hf_1-xLa_xO layer.