MOCVD and ALD of High-k Dielectric Oxides Using Alkoxide Precursors

A number of high‐permittivity (κ) dielectric oxides are currently being investigated as alternatives to SiO2 as the dielectric insulating layer in sub‐0.1 μm CMOS technology. Metal‐organic (MO)CVD and atomic layer deposition (ALD) are promising techniques for the deposition of these high‐κ dielectric oxides. In this paper it is shown how the use of “designed” metal alkoxide precursors, containing bidentate donor‐functionalized alkoxide ligands, in MOCVD leads to a marked improvement in the physical properties of the MOCVD precursors and process parameters. However, the use of such ligands is not as beneficial in the ALD process, highlighting the very different requirements of MOCVD and ALD precursors. Review: Thin films of high‐dielectric oxides (ZrO2, HfO2, lanthanide oxides) are currently under intensive investigation as alternatives to SiO2 in sub‐0.1 μm CMOS technology. This article reviews the use of new metal alkoxides containing donor‐functionalized alkoxide ligands for the MOCVD and ALD of a range of these materials. The crystal structure of [Hf(dmop)4] is shown in the Figure.