Regensburg 2013 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 17: Interfaces and surfaces
HL 17.8: Talk
Monday, March 11, 2013, 16:45–17:00, H15
Silicon surface properties after irradiation with single femtosecond laser pulses under SF6 atmosphere — •Kay-Michael Günther1, Hartmut Witte2, Jürgen Blaesing2, Alois Krost2, Thomas Gimpel3, Wolfgang Schade1,3, and Stefan Kontermann3 — 1Clausthal University of Technology, EFZN, Am Stollen 19B, 38640 Goslar, Germany — 2Otto-von-Guericke University Magdeburg, Institute for Experimental Physics, Universitätsplatz 2, 39106 Magdeburg, Germany — 3Fraunhofer Heinrich Hertz Institute, Am Stollen 19B, 38640 Goslar, Germany
Irradiating a silicon surface with femtosecond laser pulses under a SF6 atmosphere can lead to the incorporation of sulfur donors into the top layer. After several pulses on the same spot, the surface becomes roughened. Hence, with a single fabrication step, a pn-junction as well as a low reflecting surface can be created. This technique is already used to fabricate solar cells and photodetectors.
In this work, we investigate the properties of p-type silicon samples which are irradiated with a single pulse per spot. With X-ray diffraction (XRD) measurements, atomic force microscopy (AFM) and Nomarski microscopy images we show that the crystal quality of the material remains unchanged and that only the close surface region of the samples is structured by the laser. The sulfur incorporation is investigated by secondary ion mass spectroscopy (SIMS), Hall-effect measurement, photoluminescence spectroscopy as well as capacitance-voltage spectroscopy (CV) which indicates, that the incorporated sulfur atoms are partly electrically active.