Study On Characteristics Of Thermally Stable Hflaon Gate Dielectric With Tan Metal Gate

摘要

We have fabricated the thinnest equivalent oxide thickness of 0.62 nm HfLaON gate dielectric for TaN/HfLaON/SiO_x gate stack with improved thermal stability and electrical characteristics. The HfLaON film was deposited using reactive sputtering of Hf-La and Hf targets by alternate means in N_2/Ar ambience. The effects of different postdeposition annealing conditions and various La contents on the properties of HfLaON film and its interface have been investigated; the corresponding mechanisms are discussed. The gate tunneling leakage is five orders of magnitude lower than the normal polycrystalline silicon/SiO_2 structure. The effective work function with TaN metal gate is 4.06 eV.