Effects of trimethylaluminium and tetrakis(ethylmethylamino) hafnium in the early stages of the atomic-layer-deposition of aluminum oxide and hafnium oxide on hydroxylated GaN nanoclusters

• Published in: Journal of molecular modeling Vol. 19; no. 10; pp. 4419 - 4432
• Main Authors: León-Plata, Paola A., Coan, Mary R., Seminario, Jorge M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2013
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Molecular Medicine; Original Paper; Theoretical and Computational Chemistry; Interface layer; DFT; Dissociation; Wide bandgap semiconductor; Nanoclusters
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-013-1956-z

We calculate the interactions of two atomic layer deposition (ALD) reactants, trimethylaluminium (TMA) and tetrakis(ethylmethylamino) hafnium (TEMAH) with the hydroxylated Ga-face of GaN clusters when aluminum oxide and hafnium oxide, respectively, are being deposited. The GaN clusters are suitable as testbeds for the actual Ga-face on practical GaN nanocrystals of importance not only in electronics but for several other applications in nanotechnology. We find that TMA spontaneously interacts with hydroxylated GaN; however it does not follow the atomic layer deposition reaction path unless there is an excess in potential energy introduced in the clusters at the beginning of the optimization, for instance, using larger bond lengths of various bonds in the initial structures. TEMAH also does not interact with hydroxylated GaN, unless there is an excess in potential energy. The formation of a Ga—N(CH
3
)(CH
2
CH
3
) bond during the ALD of HfO
2
using TEMAH as the reactant without breaking the Hf—N bond could be the key part of the mechanism behind the formation of an interface layer at the HfO
2
/GaN interface.
Figure
Interactions of TMA and TEMAH with hydroxylated GaN