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193 nm ArF Laser Ablation of Chitosan Doped Molybdenum Complex Composite (MCC) Thin Films
Abdulsattar .A. Aesa and C.D. Walton

This paper reports the irradiation of chitosan doped MCC with excimer laser 193 nm wavelength. Laser ablation mechanism of biocompatible chitosan doped with molybdenum complex composite (MCC) film at 193 nm excimer laser irradiation was investigated and discussed. An ablation threshold of 𝑭th = 66±10 mJcm-2 was determined by etch depth measurement. An absorption coefficient of 1.7×10 4 cm-1 using absorbance spectrum date and effective absorption coefficient of 8.2×104 cm-1 were calculated. Experimental results were examined by Scanning Electron Microscopy (SEM). Nanotubes created inside the ablated crater could be well interpreted from the viewpoint of photothermal mechanism. Surface temperatures of a laser-heated the surface of thin films were determined theoretically. Temperature profiles were calculated with taking into account the optical and physical properties of the irradiated material. The results show the ability of the thin film of doped chitosan to confine the heat inside the irradiated region. Temperatures at laser fluences of ablation threshold and for the bulbous swelling and nanotubes formation using a low signal absorption coefficient were determined to be 177C and 1650C respectively.

Keywords: Laser ablation, doped biopolymer, Excimer laser ablation, dopant-induced laser ablation