Ultrafast-laser-assisted chemical restructuring of silicon and germanium surfaces

• Published in: Applied surface science 2007-05, Vol.253 (15), p.6580-6583
• Main Authors: Nayak, Barada K., Gupta, Mool C., Kolasinski, Kurt W.
• Format: Article
• Language: English
• Subjects: Chemical restructuring; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Femtosecond laser; Impact phenomena (including electron spectra and sputtering); Laser-beam impact phenomena; Materials science; Physics; Silicon and germanium surfaces; Solid surfaces and solid-solid interfaces; Surface cleaning, etching, patterning; Surface structure and topography; Surface texturing; Surface treatments; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Ultrafast lasers
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2007.01.079

This article reports a comparative study on texturing in silicon and germanium surfaces after exposure to femtosecond laser irradiation in the gaseous environments of sulfur hexafluoride (SF 6) and hydrogen chloride (HCl). The surface texturing results from the combined effect of laser-assisted chemical etching and laser ablation. Optimized processing conditions have produced features on the order of nanometers in size. We demonstrate for the first time that regular conical pillars can be formed in Ge and that HCl can be used to form regular conical pillars in Si.