Inter-diffusion of cobalt and silicon through an ultra thin aluminum oxide layer

Optical emission spectroscopy of sputtered species during ion bombardment, Auger electron spectroscopy and high-resolution transmission electron microscopy were used to study the cobalt and silicon diffusion through the interfaces of Co/AlO/Si(0 0 1) hetero-structure. The results are discussed as a function of the annealing temperature of sample and show that the diffusion process at the interfaces starts for annealing temperatures above 200 °C without detectable modification of the oxide layer.