Surface texturing of Si, porous Si and TiO2 by laser ablation

• Published in: Applied surface science Vol. 253; no. 15; pp. 6575 - 6579
• Main Authors: MILLS, D, KREOUZIS, T, SAPELKIN, A, UNAL, B, ZYUZIKOV, N, KOLASINSKI, K. W
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier Science 01.05.2007
• Subjects: 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; Impact phenomena (including electron spectra and sputtering); Laser-beam impact phenomena; Materials science; Physics; Structure and morphology; thickness; Surface treatments; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Dendritic growth; Inorganic compounds; Physical radiation effects; Porous materials; Transition element compounds; Optical fiber networks; Surface texturing; Laser ablation; Film growth; Thin films; Crystalline material; Titanium oxides; Pillar; Laser radiation; Laser ablation technique; Silicon; Surface texture; Arrays; Silicon and porous silicon; Nanocrystal; Crystal structure; TiO2
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2007.01.078

Excimer laser ablation at 308nm has been used to texture the surfaces of a variety of materials of interest for optoelectronic and biotechnological applications. Using a range of pre- and post-processing methods, we are able to produce nano-, micro- and meso-scale features over large areas rapidly in materials such as crystalline Si, porous silicon and TiO2. Texturing of porous silicon leads to the growth of crystalline dendritic structures, which distinguishes them dramatically from the conical pillars formed from crystalline silicon. Regular arrays of Si microdots are formed by irradiating a Si surface pre-covered with a Cr thin film grating. Nano-crystalline porous TiO2 films are easily ablated or compacted with laser irradiation. However, at low enough laser fluence, surface roughening without complete loss of porosity is possible.