Resumen

SALAS P, Keyffer J; GARICA, Víctor J; FERNANDEZ-ROJAS, Freddy  y  FERNANDEZ-ROJAS, Carlos. Regimes of laser ablation in thin film manufacture. Rev. Fac. Ing. UCV [online]. 2010, vol.25, n.4, pp.121-126. ISSN 0798-4065.

In the manufacture of thin film using a pulsed laser "Pulsed Laser Deposition" (PLD), a beam of laser radiation is used to remove and/or to vaporize a material that later on will be deposited on a substrate "Laser Physical Vapor Deposition" (LPVD). Using LPVD three fundamental interactions we identified: (1) laser-matter (2) plasma-gas in the camera and (3) plasma-substrate. In this work we focused on the laser-matter interaction to understand the underlying physics and so achieve a better idea of the different mechanisms of ablation that allow us to optimize the process of elaboration of thin film. The laser-matter interaction was systematized in terms of the time of interaction and the manifestation of diffusive thermal processes.. Using the laser-matter interaction time we identified three regimens of ablation: the regime of ultrashort pulses and regime of short pulses, when the duration of the pulse laser is of picoseconds or more, smaller density of power 1MW/cm² and the thermal vaporization is probably the mechanism that dominates the process of ablation. The régime of long pulses, with pulses of the order of picoseconds or less and densities of power of 1GW/cm², in this scenario, before it can vaporize the surface, matter that is below the surface reaches the temperature of vaporization causing the surface to explode. This explosive interaction has been described as non-thermal.

Palabras clave : Laser ablation; Thin film; Plasma; Pulsed laser; Deposition.