Nucleation of copper on TiN and SiO2 from the reaction of hexafluoroacetylacetonate copper(I) trimethylvinylsilane

Abstract

The nucleation of copper on TiN and SiO2 surfaces has been investigated using a collimated molecular beam of hexafluroacetylacetonate copper(I) trimethylvinylsilane in ultrahigh vacuum. The Cu thin film precursor was delivered using a bubbler with H2 as the carrier gas and the substrate temperature was varied from 150 to 260°C. Ex situ analysis of thin film morphology and microstructure has been conducted using scanning electron microscopy. On SiO2 surfaces the Cu nuclei density reaches a maximum near 5×1010cm-2, nearly independent of substrate temperature. In contrast, on TiN surfaces the maximum nuclei density is strongly dependent on temperature, varying nearly two orders of magnitude from 150 to 260°C. On TiN the nucleation process is described well by established kinetic models where a maximum in nuclei density (Nmax) is predicted with respect to the time, and where this quantity exhibits an Arrhenius dependence on substrate temperature. © 2002 American Institute of Physics.