Composition–constitution–morphology relationship of Al2O3 thin films deposited by plasma assisted chemical vapor deposition

Ab initio molecular dynamics of Al irradiation-induced processes during Al2O3 growth

“…[10][11][12][13] From these studies, it is apparent that the understanding of the effect of the energetic bombardment on the phase formation of alumina is central for further development of experimental methodologies that would in turn facilitate a decrease in the temperature limit for the growth of ␣-Al 2 O 3 . It has been suggested that energetic bombardment affects ͑i͒ nucleation of various Al 2 O 3 polymorphs, 14 ͑ii͒ bulk and surface diffusion, 10,12,15 and ͑iii͒ incorporation of impurities. 10 All these factors may in turn control the phase formation.…”

“…It has been suggested that energetic bombardment affects ͑i͒ nucleation of various Al 2 O 3 polymorphs, 14 ͑ii͒ bulk and surface diffusion, 10,12,15 and ͑iii͒ incorporation of impurities. 10 All these factors may in turn control the phase formation. In our previous work, we have used a monoenergetic Al + beam to synthesize ␣-Al 2 O 3 at energies of 40 eV.…”

“…The energy cutoff ͑150 Ry͒ and k-point grid ͑1 ϫ 1 ϫ 1͒ within the real space grid technique 33 were adjusted to reach the accuracy of 10 −6 H / atom. Canonical ensembles at 330 K ͑slightly above room temperature due to irradiation from plasma͒ were used to simulate Al bombardment of alumina slabs ͑vacuum thickness 10 16,34 Structural description of ␣-and ␥-Al 2 O 3 bulk/surfaces was adopted from literature. [35][36][37] The MD time step was 1.0 fs and the total MD simulation time was 400 fs, namely 100 fs for surface relaxations and 300 fs after bombardment events.…”

Pulsed Plasma Enhanced Chemical Vapor Deposition of Alumina Thin Films: Influence of the Duty Cycle on Structure and Elastic Properties

“…Because of productivity considerations, aluminium tri‐chloride (AlCl 3 ) precursor is often employed as precursor during PECVD of alumina coatings for wear protection applications 14. However, it has recently been demonstrated that chlorine is incorporated in the film during growth5, 7, 13 and it has been suggested that the presence of Cl may induce the formation of pores 7, 13. The elastic modulus – film density correlation was empirically determined for bulk alumina14, 15 and is described in Equation (1).…”

“…Hence growth strategies have to be devised to minimize porosity to obtain elastic properties that represent bulk values. Based on the report of Cl induced pore formation,13 the incorporation of chlorine has to be avoided or at least minimized. Increasing the deposition temperature or the power supplied to the plasma,4, 16 as well as bombarding the film with ions17 are reasonable pathways to reduce chlorine incorporation.…”