title: Nanomechanical properties of silicon surfaces nanostructured by excimer laser.
abstract: Excimer laser irradiation at ambient temperature has been employed to produce nanostructured silicon surfaces. Nanoindentation was used to investigate the nanomechanical properties of the deformed surfaces as a function of laser parameters, such as the angle of incidence and number of laser pulses at a fixed laser fluence of 5 J cm-2. A single-crystal silicon [311] surface was severely damaged by laser irradiation and became nanocrystalline with an enhanced porosity. The resulting laser-treated surface consisted of nanometer-sized particles. The pore size was controlled by adjusting the angle of incidence and the number of laser pulses, and varied from nanometers to microns. The extent of nanocrystallinity was large for the surfaces irradiated at a small angle of incidence and by a high number of pulses, as confirmed by x-ray diffraction and Raman spectroscopy. The angle of incidence had a stronger effect on the structure and nanomechanical properties than the number of laser pulses.
authors.affiliation: Chemistry and Physics of Materials Unit (CPMU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P O, Bangalore 560064, India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Materials Engineering, Indian Institute of Science (IISc), Bangalore 560012, India.
authors.forename: M S R N
authors.initials: MS
authors.lastname: Kiran
keywords: excimer laser; nanocrystallinity; nanoindentation; nanostructuring