Physical properties and electrical characteristics of H2O-based and O3-based HfO2 films deposited by ALD

Abstract Ozone (O 3 ) and H 2 O are used as the oxidant to deposit hafnium oxide (HfO 2 ) thin films on p-type Si (1 0 0) wafers by atomic layer deposition (ALD). The physical properties and electrical characteristics of HfO 2 films change greatly for different oxidants and deposition temperature. Compared with O 3 as the oxidant, HfO 2 films grown with H 2 O as the oxidant are more consistent in composition and growth rate. The O 3 -based HfO 2 films have lower C impurity and higher concentration N impurity than the H 2 O-based HfO 2 films. The impact of the annealing process on the electrical properties and stability of HfO 2 films are also investigated. A width step is observed in the O 3 -based HfO 2 C–V curves, which disappears after annealing process. It is because the unstable Hf–O–N and Hf–N bonds in O 3 -based HfO 2 films are re-bonded with the non-HfO 2 oxygen after annealing process, and the binding energy of N 1s shifts.