Influence of process parameters on atomic layer deposition of ZrO2 thin films from CpZr(NMe2)3 and H2O

Atomic layer deposition of ZrO2 films from tris(dimethylamino)cyclopentadienylzirconium CpZr(NMe2)(3) and H2O, was investigated using real-time characterization of the growth process and post-growth measurements of the films. Self-limited nature of the deposition process was observed at substrate temperatures ranging from 120 to 350 degrees C. In this temperature range growth rate of 0.08-0.1 nm per cycle was obtained on silicon substrates. The films deposited on silicon substrates at 200 degrees C and higher temperatures contained tetragonal and monoclinic phases of ZrO2. The phase composition of the films depended on the deposition temperature as well as on the film thickness. The concentration of carbon residues decreased with increasing deposition temperature and did not exceed 0.9 at.% in the films deposited at 250 degrees C and higher temperatures. The refractive indices and densities of films grown from CpZr(NMe2)(3) and H2O at 250-350 degrees C ranged from 2.15 to 2.20 (at a wavelength of 633 nm) and 5.6 to 6.0 g/cm(3), respectively, being close to the highest values obtained for films deposited from ZrCl4 and H2O. The former process ensured, however, more uniform nucleation of ZrO2 on graphene than the latter process did. (C) 2014 Elsevier B.V. All rights reserved.