Kinetic Analysis of Crystallization Processes in In60Se40 Thin Films for Phase Change Memory (Pram) Applications
Irene W. Muchira,
Walter K. Njoroge,
Patrick M. Karimi
Issue:
Volume 5, Issue 4, August 2016
Pages:
18-22
Received:
23 June 2016
Accepted:
7 July 2016
Published:
28 July 2016
Abstract: In the present work, a systematic investigation of crystallization kinetics of In60Se40 alloy has been made. Thin films of In60Se40 alloy were prepared by thermal evaporation using Edward Auto 306 evaporation system. Electrical measurements at room temperature and upon annealing at different heating rates were done by four point probe method using Keithley 2400 source meter interfaced with computer using Lab View software. The dependence of sheet resistance on temperature showed a sudden drop in resistance at a specific temperature corresponding to the transition temperature at which the alloy change from amorphous to crystalline. The transition temperature was also found to increase with the heating rates. From the heating rate dependence of peak crystallization temperature (Tp) the activation energy for crystallization was determined using the Kissinger analysis. The films were found to have an electrical contrast of about six orders of magnitude between the as-deposited and the annealed states, a good quality for PRAM applications. The activation energies were determined to be 0.354 ± 0.018 eV.
Abstract: In the present work, a systematic investigation of crystallization kinetics of In60Se40 alloy has been made. Thin films of In60Se40 alloy were prepared by thermal evaporation using Edward Auto 306 evaporation system. Electrical measurements at room temperature and upon annealing at different heating rates were done by four point probe method using ...
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Effect of Fluorine Doping on Structural and Optical Properties of SnO2 Thin Films Prepared by Chemical Spray Pyrolysis Method
Nabeel A. Bakr,
Sabah A. Salman,
Mohammed N. Ali
Issue:
Volume 5, Issue 4, August 2016
Pages:
23-30
Received:
3 July 2016
Accepted:
13 July 2016
Published:
17 August 2016
Abstract: In this study, (SnO2-xFx) thin films where (x = 0, 0.02, 0.04, 0.06 and 0.08) have been deposited by chemical spray pyrolysis method on glass substrates at temperature of (400°C), using Tin Chloride Pentahydrate (SnCl4.5H2O) and Ammonium Fluoride (NH4F) solutions. The structural properties and morphology of these films have been studied using XRD and AFM respectively. XRD analysis showed that these films are polycrystalline in nature with tetragonal Rutile structure with preferred orientation of (110). Doping with Fluorine causes a decrease in the crystallite size. The optical properties for all the films were studied by recording the transmittance and absorbance spectra in the range of (300-900) nm. The results showed that the absorbance increases with increasing the doping percentage. The optical energy gap for allowed direct electronic transition was calculated and it was found that the thin film with 0.08 doping percentage has the least value of 3.72 eV. Urbach energy decreases with increasing doping percentage. The optical constants (absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant) as a function of photon energy for all prepared films were calculated.
Abstract: In this study, (SnO2-xFx) thin films where (x = 0, 0.02, 0.04, 0.06 and 0.08) have been deposited by chemical spray pyrolysis method on glass substrates at temperature of (400°C), using Tin Chloride Pentahydrate (SnCl4.5H2O) and Ammonium Fluoride (NH4F) solutions. The structural properties and morphology of these films have been studied using XRD a...
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