Two-dimensional transient analysis of absorbing thin films in laser treatments

In this paper the transient coupled conductive-radiative field, due to a la ser heat source impinging on a thin film deposited on a substrate, has been solved in the hypothesis of one dimensionality of the optical field and of two dimensionality of the thermal field. Results have been obtained with t he matrix method for the optical field and the finite volume method for the thermal field. The results show that when the investigation is localized t o the center of the spot, the one-dimensional model describes the thermal f ield quite well. Instead, if knowledge of the temperature is required elswh ere, the tow-dimensional model si needed. The investigation herein presente d shows that for low-conductivity materials (a-Si) the temperature peaks ar e placed inside the thin film for the absorption function distribution, det ermined by interference phenomena.