Regensburg 2004 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 13: Schichteigenschaften III

DS 13.3: Vortrag

Mittwoch, 10. März 2004, 17:15–17:30, HS 31

Effect of Microwave radiation on structural and mechanical properties of Al2O3 thin films deposited by sol-gel process — •Phani Ayalasomayajula and Henry Haefke — CSEM Swiss Center for Electronics and Microtechnology Inc., CH-2007 Nuechatel, Switzerland

The lower temperatures and shorter processing time associated with microwave irradiation might be ascribed to the activating and facilitating effect of microwave energy on solid phase diffusion. Unlike other preparation methods, microwave heating is generally significantly faster, simpler, and very energy efficient. In the present work, alumina has been chosen because of its high hardness, chemical resistance, and scratch resistance properties. Thin films of Al2O3 have been deposited on quartz substrates at room temperature by a sol-gel dip coating technique. Two kinds of treatments have been applied to the as-deposited films for comparison: (1) furnace annealing at different temperatures ranging from 200oC to 1000oC for 5 hours and (2) exposure to different microwave radiation (2.45 MHz), with powers ranging from 200 W to 1000 W for 5 minutes. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray (EDX)analysis techniques have been employed to characterise the structural, morphological and elemental composition of the films. Nanohardness indentation tests of the films exposed to microwaves (600W and above) have shown a hardness of 8.5 GPa with an elastic modulus of 140 GPa compared to the annealed sample having 3.3 GPa with an elastic modulus 57 GPa.