Kinetics and Coverage Dependent Reaction Mechanisms of the Copper Atomic Layer Deposition from Copper Dimethylamino-2-propoxide and Diethylzinc

Abstract

Original citationMaimaiti, Yasheng; Elliott, Simon D. (2016) Just Accepted "Just Accepted" manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides "Just Accepted" as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. "Just Accepted" manuscripts appear in full in PDF format accompanied by an HTML abstract. "Just Accepted" manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). "Just Accepted" is an optional service offered to authors. Therefore, the "Just Accepted" Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the "Just Accepted" Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these "Just Accepted" manuscripts. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 mechanism. During both reaction mechanisms, ligand diffusion and reordering are generally endothermic processes, which may result in residual ligands blocking the surface sites at the end of the Et 2 Zn pulse, and in residual Zn being reduced and incorporated as an impurity. We also find that the nearby ligands play a cooperative role in lowering the activation energy for formation and desorption of by-products, which explains the advantage of using organometallic precursors and reducing agents in Cu ALD. The ALD growth rate estimated for the mechanism is consistent with the experimental value of 0.2 Å/cycle. The proposed reaction mechanisms provide insight into ALD processes for copper and other transition metals.

Classification of processes for the atomic layer deposition of metals based on mechanistic information from density functional theory calculations

“…In order to determine the step-by-step mechanism and possible side-reactions, we carried out DFT calculations, both a wide screening of many ligands and their intermediates, 37 and a detailed consideration of the kinetics of surface reactions 38 at various coverages. 39 We were particularly interested in finding out how the identity of ligand X affects the process, which species saturate the surface, and why co-deposition of Zn is observed to take place.…”

“…The reaction is therefore limited by the coverage of Et groups at the end of step 2b, which we have estimated 39 at four Et groups per (6 × 6) simulation cell, meaning 2 Cu atoms are deposited per cell. Further adsorption of Cu(dmap) 2 is possible in step 1b (for reduction to Cu 0 in step 2a), limited by the availability of sufficiently large segments of bare Cu.…”

Highly Material Selective and Self‐Aligned Photo‐assisted Atomic Layer Deposition of Copper on Oxide Materials

“…It was also observed that the growth rate slowed down after reaching a full coverage of the substrate. Cu(dmap) 2 has been employed as a precursor also in other ALD processes of copper metal [ 21–22 ] as well as of copper(I) oxide, [ 23 ] copper(II) oxide, [ 24 ] and hybrid copper‐organic material. [ 25 ]…”

Initial stage of atomic layer deposition of 2D-MoS2 on a SiO2 surface: a DFT study

“…This can in principle be overcome by using more accurate methods [41][42] rather than DFT. However, owing to the complicated reaction pathways that may result from densification 19 or cooperative effects 27,[43][44] , considering large cells with many atoms (e.g., here, 300 atoms with more than 1500 valence electrons) is necessary. This is too computationally demanding for the more accurate methods.…”