STRUCTURAL DEFECTS AND HYDROGEN CLUSTERING IN AMORPHOUS-SILICON

We have studied by small angle X-ray scattering the structural evoluti on on the atomic and nanoscale of hydrogenated amorphous silicon prepa red both by ion implantation and by plasma-enhanced chemical vapor dep osition and containing a similar H content. Results show that the init ial structure of both samples is homogeneous on the nanoscale. Upon an nealing, low-density features on the nanometer scale nucleate in both materials. However, the volume fractions of the nanoscale H-rich defec ts detected upon annealing and the temperature range of their evolutio n differ in the two cases. We propose that the initial structural diso rder state of the matrix determines the initial H configurations and t hereby their evolution upon annealing. (C) 1998 Elsevier Science B.V. All rights reserved.