Atomic layer deposited HfO2 and HfO2/TiO2 bi-layer films using a heteroleptic Hf-precursor for logic and memory applications

Abstract

HfO2 films were grown by atomic layer deposition (ALD) using a new heteroleptic hafnium precursor, tert-butoxytris(ethylmethylamido)hafnium (BTEMAH), and ozone. This BTEMAH precursor achieved a very high growth rate and retained excellent thermal stability in electrical performance due to the high film density of the HfO2 films. Additionally, the structural compatibility between the specific planes of tetragonal HfO2 and rutile TiO2 achieved a high dielectric constant (∼29) for HfO2 films grown on a rutile TiO2 film. It is demonstrated that this BTEMAH is a very promising precursor for the growth of HfO2 films for both the applications of a gate oxide and a capacitor dielectric.