abstract
A nonaqueous approach inspired from sol-gel chemistry and adapted to the deposition of metal oxide thin films by atomic layer deposition (ALD) is presented. The process is based on the reaction of a carboxylic acid with a metal alkoxide. Contrary to classical approaches, no oxygen source that could lead to the oxidation of the silicon substrate is required. Instead, a surface esterification reaction is responsible for the film formation. The growth of metal oxides is achieved at temperatures as low as 50 degrees C on various supports including carbon nanotubes, organic fibers, and silicon wafers. The as-grown films show an excellent conformality and possess good dielectric properties due to their high purity. Inherent to the chemical approach is the possibility to grow oxides on silicon while minimizing the formation of a low-kappa interfacial layer.
keywords
HIGH DIELECTRIC-CONSTANT; SOL-GEL ROUTES; THIN-FILMS; NONAQUEOUS SYNTHESIS; FORMATION MECHANISMS; GATE DIELECTRICS; CARBON NANOTUBE; HFO2; HAFNIUM; NANOPARTICLES
subject category
Chemistry; Science & Technology - Other Topics; Materials Science
authors
Rauwel, E; Willinger, MG; Ducroquet, F; Rauwel, P; Matko, I; Kiselev, D; Pinna, N
our authors
Nicola Pinna
ResearcherGroups
acknowledgements
The authors would like to thank Professor Dr. Wolf Widdra and Ralf Kulla from the Institute of Physics of the Martin Luther University, Halle, Germany, for support on the conception and realization of the ALD tool; Dr. Bernard Chenevier LMP-Minatec, Grenoble, France for the use of the JEOL 2010 TEM; Dr. Dangsheng Su and Rosa Arrigo from the Fritz Haber Institute of the Max Planck Society, Berlin, Germany, for supplying carbon nanotubes; and Dr. Igor Bdikin from the department of Ceramics, CICECO for the AFM study. Financial support from FCT project No. PTDC/CTM/65667/ 2006 and grant No. SFRH/BPD/36941/2007, FAME network of excellence, and Marie Curie (MEIF-CT2006-041632) is acknowledged.