Electron beam induced surface nucleation and low-temperature decomposition of metal carbonyls

Abstract

The kinetics of low-energy electron beam induced metal film nucleation have been investigated. Experiments performed were the deposition of Fe and Cr from Fe(CO)5 and Cr(CO)6, respectively. It was found that the activation energy for the autocatalytic thermal decomposition of these compounds was lower than the activation energy for decomposition on Si surface. The autocatalytic activation energies were measured as 0.14 eV for Fe(CO)5 and 1.02 eV for Cr(CO)6. The electron beam induced nucleation, together with the rapid autocatalytic decomposition, allowed for selective area metal film growth. A qualitative model based on classical nucleation theory describes well the effect of electron irradiation in inducing film growth. The electron beam induced nucleation step has been modeled in more detail and shows a t4 dependence for the early stages of film growth, in agreement with the observed data.