Anomalous Carbon Interdiffusion in a-Si:H/a-SiC:H Multilayers

The interdiffusion of carbon in a-Si:H and a-Si1-xCx:H multilayers is measured by analyzing the time evolution of the X-ray diffraction from the superlattices. A time dependent diffusivity D(t)which follows a power law is found. The theoretical analysis shows that such a time dependence, referred to as "dispersive" or "anomalous" diffusion and studied for hydrogen diffusion in the literature, is fundamentally related to the amorphous structure of the material.