Abstract
We report here on the results of a systematic investigation of the interfacial reactions and microstructural evolution of nanoscale Ni metal dots on N 2 + -implanted amorphous Si (a-Si) substrates under different annealing conditions. During annealing, Ni 2 Si was the first phase to form, followed by NiSi and NiSi 2 . The three Ni-silicide phases formed were polycrystalline and the average sizes of the annealed nanodots were observed to increase with the annealing temperature, up to 500 °C. After a further increase of the annealing temperature and/or time, it is interesting to note that the NiSi 2 grains gradually migrated outward from their original nanodot positions to the a-Si regions, which resulted in the formation of a remarkable NiSi 2 nanoring structure. The inner regions of the NiSi 2 nanorings were found to be comprised of a single crystalline Si phase, indicating mediation of the epitaxial crystallization of N 2 + -implanted a-Si by the lateral migration of the NiSi 2 nanodots. Furthermore, the annealing temperature required for complete recrystallization of the a-Si layer in the Ni nanodot/N 2 + -implanted a-Si sample could be significantly reduced to 550 °C, 200 °C lower than that which was required the blank N 2 + -implanted a-Si sample. It is suggested that the formation of these remarkable NiSi 2 nanoring structures and the enhancement of N 2 + -implanted a-Si recrystallization in the presence of NiSi 2 nanodots were due to the silicide-induced crystallization mechanism.
Original language | English |
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Pages (from-to) | 313-321 |
Number of pages | 9 |
Journal | Applied Surface Science |
Volume | 399 |
DOIs | |
State | Published - 31 Mar 2017 |
Keywords
- Amorphous Si
- N -implantation
- Nanoring
- Nanosphere lithography
- Ni silicide