Properties of oxide film atomic layer deposited from tetraethoxy silane, hafnium halides, and water

• Published in: Journal of the Electrochemical Society 2004, Vol.151 (5), p.F98-F104
• Main Authors: KUKLI, Kaupo, RITALA, Mikko, LESKELÄ, Markku, SAJAVAARA, Timo, KEINONEN, Juhani, HEGDE, Rama I, GILMER, David C, TOBIN, Philip J
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1668925

Hafnium silicate thin films were grown by atomic layer deposition at 300 and 500DGC on HF-etched silicon and borosilicate glass substrates. The films were grown by alternating exposure of the substrate surface to gaseous Si(OC2H4)4 and Hfl4 or HfCl4 flows. H2O was used as an additional oxygen precursor in hydrolysis reactions. Silicate films were also grown without H2O. The application of H2O resulted in increased growth rate and improved density and dielectric performance of the films. The silicate films were amorphous. Their effective permittivity typically varied between 6 and 10. The composition of the films, determined by ion beam analysis, was uniform throughout the film thickness, approaching the stoichiometry of HfSiO4. X-ray photoelectron spectroscopy revealed that the thinnest films grown were somewhat silicon-rich. The silicon content was twice the hafnium content. Low amounts of residual chlorine, iodine, and carbon ( < 0.1-2 atom %) were detected in the as-deposited films.