Abstract

Al₂O₃ films have been grown by atomic layer deposition (ALD) using reactions between AlCl₃ and Al(OⁱPr)₃. In this process the aluminium alkoxide serves as both a metal and an oxygen source. No separate oxygen source is required. With this approach an Al₂O₃ film has been deposited on silicon without an interfacial silicon oxide layer. The film growth rate was 0.8 Å cycle⁻¹. The residual contents of chlorine, hydrogen and carbon in the film deposited at 300 °C were 1.8, 0.7 and <0.1 at.%, respectively. The chlorine content diminished rapidly with increasing growth temperature. The permittivities and leakage current densities were comparable to the conventional Al₂O₃ ALD processes for thick films, but the permittivity decreased for very thin films. Post deposition annealing is required to improve electrical properties of thin films.