Atomic Layer Modulation of Multicomponent Thin Films through Combination of Experimental and Theoretical Approaches

Abstract

We proposed the concept of atomic layer modulation (ALM) based on precursor chemical reactivities and steric hindrance effects to fabricate multicomponent nanofilms. Because ALM employs consecutive precursor exposures followed by exposure to a counter reactant, the composition of ALM films is determined by the molecular size and chemical reactivities of the precursors. For the demonstration, dicarbonyl-bis(5-methyl-2,4-hexanediketonato)­Ru­(II) (Carish) and trimethylaluminum (TMA) were used as Ru and Al precursors, respectively, and H2O was used as the counter reactant. Prior to the experiments, the chemical reactivity and sterically hindered physisorption of the Ru and Al precursors were theoretically calculated using density functional theory (DFT) and Monte Carlo (MC) simulations, respectively. The transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) results were highly consistent with the theoretical results, and the growth characteristics were well explained by the MC- and DFT-based reaction models. We believe that ALM could be extended to other material systems, thereby providing a different method of fabricating multicomponent nanofilms for various applications including semiconductors and nanodevices.

Gradient area-selective deposition for seamless gap-filling in 3D nanostructures through surface chemical reactivity control

“…Employing the previously-developed MC simulation, we investigated the physical adsorption and coverage of TMPMCT 8 , 12 , 31 by only considering the physical steric hindrance of TMPMCT on a surface and using the adsorption configuration from the DFT calculation. Figure 2e depicts the areal coverages of TMPMCT on the TiO 2 surface and TDMAT on the TMPMCT-inhibited surface.…”

Area-Selective Deposition of Ruthenium Using Homometallic Precursor Inhibitor

“…After the adsorption of Ru­(EtCp) 2 , the outer surface of the Ru substrate converts into an EtCp-terminated surface. Therefore, in the next Ru ALD process, it is assumed that Carish adsorbs on the EtCp-terminated surface by losing CO ligands. , There is no significant reaction between the EtCp-terminated surface and Carish, as shown in Figure a. The E ads value of this reaction is +2.10 eV, indicating that the reaction is unfavorable.…”

“…The MC simulations were performed using a modified algorithm ,, that ran on the “R” simulation program (version 3.6.1; GUI 1.70; EL Capitan build 7684). We demonstrated the adsorption behavior of Ru­(EtCp) 2 on the Ru substrate surface through areal coverage in an ideal case.…”

“…As a result, the EtCp-terminated surface was converted to a OHCp-terminated surface. The stochastic adsorption of Carish on the EtCp-terminated and OHCp-terminated surfaces was calculated on the basis of the ligand size and molecular structure, including two large diketonato ligands. , An additional H 2 O pulse was applied to improve the inhibitor packing density, and the adsorption behavior of the sequential exposure, i.e., Ru­(EtCp) 2 –H 2 O–Ru­(EtCp) 2 , was simulated and calculated. The areal coverage was calculated using the MC results, as given by the following formula …”

Elucidating the Reaction Mechanism of Atomic Layer Deposition of Al2O3 with a Series of Al(CH3)xCl3–x and Al(CyH2y+1)3 Precursors

“…We ran the simulations 100 times for all cases and have included the error range of areal coverage of the precursors. This methodology is not limited to this work and can be applied to other precursors/molecules to study changes in areal coverage by different molecular structures. − …”