MODIFICATION OF SILICON SURFACE UNDER INFLUENCE OF RADIATION OF A NANOSECOND ULTRAVIOLET LASER

Abstract

The effect of radiation of a nanosecond ultraviolet laser ( λ = 355 nm, pulse duration 10 ns, pulse energy up to 8 mJ, pulse repetition rate – up to 100 Hz) on a silicon single crystal has been investigated by methods of the optical profilometry and scanning electron microscopy. At an energy density of ≥ 1,2 J/сm^2, formation of the plasma torch and crater was observed. At an energy density of ≥ 0,2 J/сm^2, pockets of microbreakdown appeared on processing defects, and traces of uncontrolled surface uplift were recorded. Irradiation with a scanning laser beam at an energy density of 0,2 J/сm^2 forms microcraters on a surface with a size of several microns. With an increase in the energy density, the size of the microbreakdowns increased, and at an energy density ≥ 0,7 J/сm^2, the impact of the scanning beam forms a continuous damage zone.

Keywords

• laser impact
• silicon single crystal
• uv laser
• nanosecond pulse
• micro- and nanomodification of the surface
• plastic deformation