Laser assisted fabrication of random rough surfaces for optoelectronics

• Published in: Applied surface science Vol. 258; no. 23; pp. 9171 - 9174
• Main Authors: Brissonneau, V., Escoubas, L., Flory, F., Berginc, G., Maire, G., Giovannini, H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical 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; Laser-beam impact phenomena; Materials science; Optics; Physics; Random; Rough; Scattering; Structuration; Surface cleaning, etching, patterning; Surface treatments; Structuration; Random; Scattering; Rough; Laser; Optoelectronics; Etching; Rough surfaces; Laser beams
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.10.137

► Random rough surfaces are photofabricated using an argon ion laser. ► Speckle and surface correlation function are linked. ► Exposure beam is modified allowing tuning the correlation. ► Theoretical examples are presented. ► Experimental results are compared with theoretical expectation. Optical surface structuring shows great interest for antireflective or scattering properties. Generally, fabricated surface structures are periodical but random surfaces that offer new degrees of freedom and possibilities by the control of their statistical properties. We propose an experimental method to create random rough surfaces on silicon by laser processing followed by etching. A photoresist is spin coated onto a silicon substrate and then exposed to the scattering of a modified laser beam. The beam modification is performed by using a micromirror matrix allowing laser beam shaping. An example of tuning is presented. An image composed of two white circles with a black background is displayed and the theoretical shape of the correlation is calculated. Experimental surfaces are elaborated and the correlation function calculated from height mapping. We finally compared the experimental and theoretical correlation functions.