Abstract

Laser processing studies of semiconductors like silicon are crucial for practical applications in the field of nano-fabrication. Numerical modeling allows us to study the dynamics of laser excitation in detail. As an extension of the density-dependent Two-Temperature model (J.K. Chen et.al, Int. J. Heat Mass Transf., 48(3):501-509 (2005)), we have developed a Three-Temperature model (3TM) which considers three distinct temperatures for electrons, holes and the lattice. We also consider the effect of changing laser field during the interaction and the effect of band re-normalization on the optical properties of silicon (P. Venkat and T. Otobe, Applied Physics Express, 15(4), 041008 (2022)). In this work, we further study the effect of parameters such as laser wavelength and silicon film thickness on the damage threshold during laser excitation. Figure 1 (a) shows the threshold for breaking of bonds calculated using 3TM for different laser wavelengths over a varying pulse duration, along with experimental data from three different studies.

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