Etching Rate Enhancement of Porous Silicon Produced by Lasers


Two laser systems work with different operational modes have been used toproduce silicon nanostructure surfaces. Pulsed Nd:YAG laser has been employed toproduce silicon textured surface which containing nano/microstructures. Effects oflaser energies (80 – 200) mj were examined to produce surface of different structures.While Diode laser (532 nm) of fixed power (50 mW) was used in the second stage tomodify the porous structure over the textured surface. The effect of different surfacemorphology on the laser induced etching process was studied using atomic forcemicroscope (AFM) and an image processing program to sketch the surface plot to thesamples depending on the optical microscope photos. The photoluminescence spectrahave been utilized to study the nanocrystallite size distribution in porous silicon, itshows high peak position lies in (2 - 2.1) eV.