Thickness Dependence of Laser Damage in Silicon Thin Films.

We have investigated the interaction of intense laser pulses with silicon film using the one-dimensional Three-Temperature Model previously presented by Venkat and Otobe (Applied Physics Express, 15(4), 041008 (2022)). Our study focuses on how the excitation process in thin films, ranging from tens of nanometers to a few microns, is affected by the interference of the laser field at a wavelength of 775 nm. Our findings show that when the thickness of the film is less than 1.5 µm, the damage thresholds exhibit oscillations due to the interference of the laser field over a period of 100 nm, which is equivalent to half the wavelength in silicon. We also observe that the thermal damage threshold of the rear surface and inside film is lower than that of the front surface when the thickness is less than 0.3 µm and 0.5 µm, respectively. These results emphasize the significance of the size effect in the laser processing of silicon and have important implications for the optimization of the laser processing techniques of silicon. [ABSTRACT FROM AUTHOR]