Atomic layer deposition and characterization of biocompatible hydroxyapatite thin films

• Published in: Thin solid films Vol. 517; no. 20; pp. 5819 - 5824
• Main Authors: Putkonen, Matti, Sajavaara, Timo, Rahkila, Paavo, Xu, Leiting, Cheng, Sulin, Niinistö, Lauri, Whitlow, Harry J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 31.08.2009; Elsevier
• Subjects: Atomic layer deposition; Biocompatibility; Cell culture; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Hydroxyapatite; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Vapor phase epitaxy; growth from vapor phase; Cell culture; Biocompatibility; Hydroxyapatite; Atomic layer deposition; Stoichiometry; Atomic layer method; Amorphous thin film; Surface morphology; Crystallinity; Crystal growth from vapors; Polystyrene; Borosilicate glass; Thin films; Rapid thermal annealing; Silicon; Carbonates; Cell cultures
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2009.03.013

Atomic layer deposition (ALD) was used to produce hydroxyapatite from Ca(thd) 2 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) and (CH 3O) 3PO onto Si(100) and Corning (0211). Film crystallinity, stoichiometry, possible impurities and surface morphology were determined. The as-deposited films contained significant amounts of carbonate impurities however, annealing at moist N 2 flow reduced the carbonate content even at 400 °C. The as-deposited Ca–P–O films were amorphous but rapid thermal annealing promoted the formation of the hydroxyapatite phase. Mouse MC 3T3-E1 cells were used for the cell culture experiments. According to the bioactivity studies cell proliferation was enhanced on as-deposited ALD-grown Ca–P–O films and greatly enhanced on films annealed at 500 °C in comparison with reference cells on borosilicate glass or cell culture polystyrene.