Mechanism and kinetics of thin zirconium and hafnium oxide film growth in an ALD reactor

Modeling Mechanism and Growth Reactions for New Nanofabrication Processes by Atomic Layer Deposition

“…[ 44 ] Kinetic Monte Carlo (KMC) simulations of ALD are developed and used to investigate the reaction of HfCl 4 +H 2 O on Si and SiO 2 substrates (see section 6.4 ). [45][46][47] DFT calculations are also used to compare the ALD growth kinetics of HfO 2 and Hf x Si y O 2 fi lms by studying the reactions of HfCl 4 +H 2 O on H-terminated Si and on Si(OMe) 4 -pretreated Si substrates. [ 48 ] Our study of Hf(NMe 2 ) 4 +H 2 O on HfO 2 [ 49 ] shows that repeated proton diffusion from the surface to multiple amide ligands and rotation of the protonated amines without desorption is more energetically accessible than the simple elimination of the amine ligands one at a time.…”

“…[ 45 ] The fi rst half reaction of ZrO 2 ALD using the precursor Cp 2 ZrMe 2 is also simulated using DFT. [ 52 ] All of the foregoing models assume -mostly for reasons of computational necessity -that ligands are eliminated from an isolated precursor fragment because of the Brønsted acidity of surrounding hydroxyl groups.…”

“…[ 45 ] The temperature-dependence of residual chlorine in the fi lm can be traced back to steric hindrance between adsorbates. Heterdeposition of high-k oxides onto Si is simulated in lattice KMC by Mazaleyrat et al (Al 2 O 3 ) [ 116 ] and Dkhissi et al (HfO 2 ), [ 46,47 ] again based on DFT data, revealing the effect on fi lm growth of substrate hydroxylation, temperature and pulse durations.…”

Dynamic Modeling for the Design and Cyclic Operation of an Atomic Layer Deposition (ALD) Reactor

“…Although the sticking coefficient is widely used in modeling work, the experimental and computational manner in which it is determined varies, such that absolute values are rarely reported in the literature [35]. An alternative to the sticking coefficient approach is to couple transient plug-flow reactor dynamics with kinetic expressions containing rate constants derived from ab initio quantum-chemical calculations and the quantum-statistical theory of chemical reactions [36]. Yet another approach is to use the absolute reaction rate theory and statistical thermodynamics to derive kinetic expressions without the use of adjustable parameters [11].…”

Atomic-scale simulation of ALD chemistry

“…The coverage-dependence of water adsorption and surface acidity is added to the picture in cluster calculations by Deminsky et al [100] (confirmed later in a periodic model [101]) and the authors note that "the mechanism and kinetics of the ALD process cannot be interpreted even qualitatively without taking into account stereochemical effects, in particular, the effects of surface coverage on the reactivity of chemisorbed surface species. "…”