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Article
Microhardness of Nanostructured SixN1-x Thin Films Prepared by Reactive Magnetron Sputtering

Authors: Ahmed A. Anber --- Firas Kadhim
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 2 Pages: 15-19
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

Nanostructured silicon nitride (SixN1-x) thin films were prepared by reactive magnetron sputtering using Ar/N2 gas mixture of 1:1. The structures and fractional compositions of the prepared samples were determined by x-ray diffraction (XRD) and electron-dispersion x-ray diffraction (EDS) patterns as functions of inter-electrode distance. They showed that the prepared films were polycrystalline and the partial amount of silicon (x) is ranging in 0.825-0.865 as the inter-electrode distance was ranging in 2.5-7.5cm. The particle sizes of the prepared nanostructured were determined by the field-effect scanning electron microscopy (FE-SEM) to be about 38nm. Also, the highest value of the surface roughness of the prepared nanostructures was determined by the atomic force microscopy (AFM) and found to increase with increasing inter-electrode distance to be 29.00nm for the samples prepared at 7.5cm. The measured Vickers microhardness of the prepared films showed relatively high values (570-750) and was decreased with decreasing film thickness, which is inversely proportional to the inter-electrode distance. However, no uniform relation between the microhardness and fractional composition of the prepared sample was observed.


Article
Preparation and Characterization of Silicon Nitride Nanostructures Prepared by DC Reactive Sputtering Technique with Novel Design of Closed-Field Unbalanced Dual Magnetron Assembly

Authors: Firas J. Kadhim --- Mohammed K. Khalaf --- Oday A. Hammadi
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2017 Volume: 13 Issue: 3 Pages: 3-12
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, novel design of closed-field unbalanced dual magnetrons system was employed in a DC reactive sputtering system to prepare silicon nitride nanostructures. Two types of silicon wafers (n- and p-type) were sputtered in presence of nitrogen gas to deposit nanostructured silicon nitride thin films on glass substrates. The prepared nanostructured were polycrystalline with six dominant crystal planes: (101), (110), (200), (232), (301) and (321). The surface roughness of the sample prepared at inter-electrode distance of 4cm was higher than other samples prepared at smaller or larger distances and the average and R.M.S roughness were 0.777 and 1.03 nm, respectively. The nanoparticles of minimum size of 30nm were formed and recognized as individual accumulated particles. Two bands of significant absorption were observed around 960 and 1086 cm-1, those are attributed to the Si-N-Si vibration mode in Si3N4 molecule. An absorption peak was observed at 389nm, which is attributed to the quantum size effect of nanostructures. The refractive index of the prepared Si3N4 samples was determined to be 1.38-2.1 and the energy band gap was ranging in 5.1-5.2 eV. The energy band gap was found to increase with decreasing thickness of the prepared film. The wide energy band gap of Si3N4 nanostructures makes them good candidate, as similar as AlN, BN and GaN, for power electronics and optoelectronics operating at high temperatures.


Article
Structural Characteristics of Silicon Nitride Nanostructures Synthesized by DC Reactive Magnetron Sputtering

Authors: Baraa K. Nasser --- Mohammed A. Hameed
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2019 Volume: 15 Issue: 4 Pages: 33-36
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, silicon nitride nanostructures were synthesized by dc reactive magnetron sputtering technique. The effect of deposition time on the structural characteristics, especially structural purity and nanoparticle size, was determined. Long deposition time allows more silicon atoms sputtered from the target to bond to nitrogen atoms and form silicon nitride molecules. Therefore, the structure of the final product is highly dominated by silicon nitride as confirmed by the x-ray diffraction pattern. On the other hand, nanoparticles with larger size were grown at long deposition time. As the deposition time was increased from 3 to 4 hours, the nanoparticle size was increased from 26.10 to 101.20 nm. The structural characteristics of silicon nitride nanoparticles can be sufficiently controlled by the preparation conditions to serve certain applications based on nanoparticle size.

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