SILICON SURFACE MICROSTRUCTURING BY SINGLE-EXPOSURE FEMTOSECOND DOUBLE LASER PULSE

Abstract

Subject of Research. The paper evaluates the possibility of periodic microstructures formation on the silicon surface by single-exposure double femtosecond laser pulse. Method. We used experimental method of double femtosecond laser pulses based on the Michelson interferometer and theoretical numerical simulation method of semiconductor photoexcitation process in the dielectric constant approximation. Main Results. Experimental results are presented on the monocrystalline silicon surface irradiation with one double femtosecond laser pulse near the ablation threshold at various time delays. Obtained optical images of the laser-irradiated silicon surface are analyzed and the results are compared with the results of photoexcitation process theoretical simulation in semiconductor based on the polariton theory concepts. The problematic nature of the periodic surface microstructures formation on silicon by a single femtosecond laser pulse is demonstrated. Practical Relevance. This study is useful when choosing industrially advantageous high-frequency modes of semiconductor surface femtosecond microstructuring.

Keywords

• surface electromagnetic wave
• femtosecond microstructuring
• monocrystalline silicon