The Effects of a Thin Film Dopant Precursor on the Structure and Properties of
Femtosecond-laser Irradiated Silicon
M. J. Smith, M. T. Winkler, M. Sher, Y. Lin, E. Mazur and S. Gradečak
Appl. Phys. A, 105, 795-800 (2011). export citation
Femtosecond (fs) laser irradiation of a silicon substrate coated with a thin film is a flexible approach to producing metastable alloys with unique properties, including near-unity sub-band gap absorptance extending into the infrared. However, dopant incorporation from a thin film during fs-laser irradiation is not well understood. We study the thin film femtosecond-laser doping process through optical and structural characterization of silicon fs-laser doped using a selenium thin film, and compare the resulting microstructure and dopant distribution to fs-laser doping with sulfur from a gaseous precursor. We show that a thin film dopant precursor significantly changes the laser-material interactions, modifying both the surface structuring and dopant incorporation processes and in turn affecting p-n diode behavior.