Growth mechanism of Al2O3 film on an organic layer in plasma-enhanced atomic layer deposition

Differences in the physical and chemical properties of Al2O3 films on a Si wafer and a CxHy layer were investigated in the case of plasma-enhanced atomic layer deposition. The Al2O3 film on the Si had a sharper interface and lower thickness than the Al2O3 film on the CxHy. The amount of carbon-impurity near the interface was larger for Al2O3 on the CxHy than for Al2O3 on the Si. In order to understand these differences, the concentrations of Al, O, C, and Si atoms through the Al2O3 films were evaluated by using x-ray photoelectron spectroscopy (XPS) depth profiling. The emission intensities of CO molecule were analyzed for different numbers of deposition cycles, by using time-resolved optical emission spectroscopy (OES). Finally, a growth mechanism for Al2O3 on an organic layer was proposed, based on the XPS and OES results for the Si wafer and the CxHy layer.