On adsorption of aluminium and methyl groups on silica for TMA/H2O process in atomic layer deposition of aluminium oxide nano layers

Bulletin of materials science

Anu Philip¹  K Rajeev Kumar¹ 

[1] Department of Instrumentation, Cochin University of Science and Technology, Cochin 682 022, India$$Department of Instrumentation, Cochin University of Science and Technology, Cochin 682 022, IndiaDepartment of Instrumentation, Cochin University of Science and Technology, Cochin 682 022, India$$

关键词: ALD;    chemisorption;    aluminum oxide.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

A detailed chemisorption mechanism is proposed for the atomic layer deposition (ALD) of aluminium oxide nano layers using trimethyl aluminum (TMA) and water as precursors. Six possible chemisorption mechanisms, complete ligand exchange, partial ligand exchange, simple dissociation, complete dissociation via ligand exchange, complete dissociation and association, are proposed and related parameters like ligand to metal ratio (L/M), concentrations of metal atoms and methyl groups adsorbed are calculated and compared against reported values. The maximum number of methyl groups that can get attached on the surface is calculated in a different way which yields a more realistic value of 6.25 per nm² substrate area. The dependence of the number of metal atoms adsorbed on OH concentration is explained clearly. It is proposed that a combination of complete ligand exchange and complete dissociation is the most probable chemisorption mechanism taking place at various OH concentrations.

【 授权许可】

Unknown