Comparative study of Si wafer and SiO2 crystal under femtosecond laser pulses excitation.

F. C. ALVIRA; G. A. TORCHIA

Playa del Carmen

Conferencia; XI International Conference On Laser Ablation; 2011

  We have analyzed Si on two different environments. On one hand, experiments were done with a semiconductor Si wafer. By other way a dielectric material was used, SiO2. The possibility that gives Si of being in two different kind of material is exploited in this paper to 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. Extinction time of both plasmas is different, depending on the kind of sample under study, which is Si semiconductor or Si dielectric.