Opto-Structural Properties of Silicon Nitride Thin Films Deposited by ECR-PECVD
| Autor: | A. Hannour, H. Charifi, Hassan Chaib, Abdelilah Slaoui, Jean Paul Stoquert |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Hydrogen Analytical chemistry chemistry.chemical_element 02 engineering and technology 021001 nanoscience & nanotechnology Rutherford backscattering spectrometry 01 natural sciences Amorphous solid Elastic recoil detection chemistry.chemical_compound chemistry Silicon nitride Plasma-enhanced chemical vapor deposition 0103 physical sciences Thin film 0210 nano-technology Stoichiometry |
| Zdroj: | World Journal of Condensed Matter Physics. :7-16 |
| ISSN: | 2160-6927 2160-6919 |
| DOI: | 10.4236/wjcmp.2016.61002 |
| Popis: | Amorphous hydrogenated silicon nitride thin films a-SiNx:H (abbreviated later by SiNx) were deposited by Electron Cyclotron Resonance plasma enhanced chemical vapor deposition method (ECR-PECVD). By changing ratio of gas flow (R = NH3/SiH4) in the reactor chamber different stoichiometric layers x = [N]/[Si] ([N] and [Si] atomic concentrations) are successfully deposited. Part of the obtained films has subsequently undergone rapid thermal annealing RTA (800°C/1 s) using halogen lamps. Optical and structural characterizations are then achieved by spectroscopic ellipsometry (SE), ion beam analysis and infrared absorption techniques. The SE measurements show that the tuning character of their refractive index n(λ) with stoichiometry x and their non-absorption properties in the range of 250 - 850 nm expect for Si-rich SiNx films in the ultraviolet UV range. The stoichiometry x and its depth profile are determined by Rutherford backscattering spectrometry (RBS) while the hydrogen profile (atomic concentration) is determined by Elastic Recoil Detection Analysis (ERDA). Vibrational characteristics of the Si-N, Si-H and N-H chemical bonds in the silicon nitride matrix are investigated by infrared absorption. An atomic hydrogen fraction ranging from 12% to 22% uniformly distributed as evaluated by ERDA is depending inversely on the stoichiometry x ranging from 0.34 to 1.46 as evaluated by RBS for the studied SiNx films. The hydrogen loss after RTA process and its out-diffusion depend strongly on the chemical structure of the films and less on the initial hydrogen concentration. A large hydrogen loss was noted for non-thermally stable Si-rich SiNx films. Rich nitrogen films are less sensitive to rapid thermal process. |
| Databáze: | OpenAIRE |
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