Interface induced diffusion.

Interface induced diffusion had been identified in a thin film system damaged by electron bombardment. This new phenomenon was observed in AlO (some nm thick)/Si substrate system, which was subjected to low energy (5 keV) electron bombardment producing defects in the AlO layer. The defects produced partially relaxed. The rate of relaxation is, however, was different in the vicinity of the interface and in the "bulk" parts of the AlO layer. This difference creates an oxygen concentration gradient and consequently oxygen diffusion, resulting in an altered layer which grows from the AlO/Si substrate interface. The relative rate of the diffusion and relaxation is strongly temperature dependent, resulting in various altered layer compositions, SiO (at room temperature), AlO + AlO + Si (at 500 °C), AlO + Si (at 700 °C), as the temperature during irradiation varies. Utilizing this finding it is possible to produce area selective interface patterning.