Comparative study of plasmas obtained by femtosecond laser pulses ablation in Si and SiO2

F.C. ALVIRA; G.A. TORCHIA

Playa del Carmen

Conferencia; Conference on Laser Ablation (COLA); 2011

In this work we study the behavior of the ablation plasmas in materials where Silicon atoms are placed on two different environments. On one hand, experiments were done with a semiconductor Si wafer and by other way a dielectric material SiO2 was used. The possibility giving by Si of being present as constitutive elements in two different kind of material is exploited in this paper. With this fact in mind we show how the availability of electrons in Si (there is a wider band gap in dielectrics than in semiconductors) plays a role not only in plasma formation but in his dynamic. Experiments were done using a femtosecond laser as excitation source and a Czwerny-Turner imaging with an ICCD camera as detection system. This detection system gives the possibility of study the plasma dynamics with spatial and temporal resolution. Electronic density and temperature were measured with spatial and temporal resolution on SiO2 and Si. Our results show a different dynamic of the plasma generated in semiconductor and dielectric material as well as the extinction time of both plasmas are different. We can conclude during ablation process that the different quantity of electrons present in the conduction band in both kind of samples play a crucial role in the femtosecond plasma dynamics.