Optical, structural evolution and surface morphology studies of hydrogenated silicon films synthesized by rf-magnetron sputtering: Effects of pressure and radio frequency power at low temperature
| Autor: | Y. Bouizem, D. Benlakehal, L. Chahed, A. Kebab, Ahmed Bouhekka, J.D. Sib, F. Zeudmi Sahraoui |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Silicon Band gap Analytical chemistry chemistry.chemical_element 02 engineering and technology Substrate (electronics) Sputter deposition 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention Amorphous solid symbols.namesake Microcrystalline chemistry law 0103 physical sciences symbols Electrical and Electronic Engineering Crystallization 0210 nano-technology Raman spectroscopy |
| Zdroj: | Optik. 168:65-76 |
| ISSN: | 0030-4026 |
| DOI: | 10.1016/j.ijleo.2018.03.097 |
| Popis: | In the present work, three series of hydrogenated silicon thin films were prepared by radiofrequency magnetron sputtering method at low temperature, various deposition pressures (2, 4, 6 Pa) and different rf powers (200, 300, 400, 500 W) while all the other plasma parameters were fixed. The deposited films were characterized using atomic force microscopy (AFM), Fourier transform infrared (FTIR), UV–vis-NIR spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and DC electrical conductivity. The results show that rf power and pressure play an important role on optical band gap, the content of hydrogen, crystalline volume fraction, grain size and the surface roughness. The samples prepared at 6 Pa show the phase transition from amorphous, polymorphous to microcrystalline with increasing rf power. This transition is accompanied by an increase of the crystalline volume fraction and grain size, where hydrogen rich amorphous matrix enhances the crystallization. The variation of the optical band gap with the rf power was found to be dependent on the structure and hydrogen content. We conclude that increasing rf power favors the growth of microcrystalline films where the substrate was reheated by a high energy ions bombardment. The activation energy decreases linearly with increasing crystalline volume fraction. |
| Databáze: | OpenAIRE |
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