Nanosecond Fabrication of Hyperdoped Silicon

Abstract

Under the action of multipulse (≈40‒100 pulses per point) laser radiation at a wavelength of 532 nm and a pulse duration of 10 ns in an atmosphere of SF₆ gas, structures doped with a sulfur donor impurity are fabricated on the silicon surface. The topography of the laser-structured surface is characterized by scanning electron microscopy (SEM). Energy-dispersive X-ray microanalysis of the surface layer is indicative of the presence of up to ≈2 at % of the doping donor sulfur impurity. Fourier-IR spectroscopy shows broadband absorption for the structured samples. Using the Raman spectroscopy data, the appearance of an amorphous phase in structured silicon is demonstrated and the sizes of nanocrystallites are estimated to be ~4‒20 nm.