Raman-based mapping and depth-profiling of the relaxation state in amorphous silicon
Date de publication
Contributrices et contributeurs
Direction de recherche
Publié dans
Date de la Conférence
Lieu de la Conférence
Éditeur
Cycle d'études
Programme
Mots-clés
- Signal-to-noise ratio
- Amorphous materials
- Materials heat treatment
- Microstructural properties
- Photolithography
- Raman spectroscopy
- Depth profiling techniques
Organisme subventionnaire
Résumé
We show that the micro-scale variations in the relaxation state of amorphous silicon (aSi) can be well-identified by Raman mapping over hundreds or thousands of µm2 in 1-2 hours. Pure and relaxed a-Si is obtained by self-implantation in crystalline silicon (c-Si) followed by an anneal at 500°C. It is then locally re-implanted over micro-sized patterns to produce unrelaxed aSi zones. Raman mappings are obtained by pointwise confocal µ-Raman and Hyperspectral Raman Imaging (RIMA). We also measure depth profiles of the relaxation state in re-implanted a-Si by scanning the edge of a re-implanted sample. We infer from the depth profiles that the minimal damage dose to fully de-relax a-Si is 0.04 displacements per atoms, which is an order of magnitude smaller than the fluence needed to fully amorphize c-Si.