Cubic/Tetragonal Phase Stabilization in High-κ ZrO2 Thin Films Grown Using O3-Based Atomic Layer Deposition

Among the widespread range of applications in which ZrO 2 thin films are of interest, they are receiving a peculiar consideration as candidate replacement material in innovative microelectronic devices, such as non volatile memories. In this work, we deposited ZrO 2 films on Si (100) substrates by atomic layer deposition at 300°C from (MeCp) 2 ZrMe(OMe) as Zr precursor and using, H 2 O or O 3 as oxygen source. After deposition films were subjected to rapid thermal annealing at 800 °C for 60 s in N 2 . Film thickness is calculated from X-ray reflectivity to be in the 5–60 nm range. Grazing incidence X-ray diffraction reveals that the film crystallographic phase is highly influenced by the oxidizing agent used during the deposition process. While the use of H 2 O gives films consisting of mixed phases, the monoclinic phase is almost absent in films deposited employing O 3 , which stabilize in the ZrO 2 cubic/tetragonal phases. Upon annealing, the films retain their crystallographic structure, despite a marginal increment of the monoclinic phase. Time of flight secondary ion mass spectrometry depth profiles evidence film uniformity and thermal stability. The evolution of electrical properties of ZrO 2 films is discussed as a function of oxygen precursor and thermal treatment. The measured dielectric constant values after 800 °C annealing are κ ∼ 24 and κ ∼ 30 in the films deposited using H 2 O or O 3 respectively, in agreement with the different crystallographic phases in the ZrO 2 films.