Surface Roughness Modification of Free Standing Single Crystal Silicon Microstructures Using KrF Excimer Laser Treatment for Mechanical Performance Improvement
Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52943#.VK3YEMnQrzE Author(s) Mohamed Elwi Mitwally 1* , Toshiyuki Tsuchiya 1 , Osamu Tabata 1 , Sherif Sedky 2 Affiliation(s) 1 Department of Micro Engineering, Kyoto University, Kyoto, Japan . 2 Zewail City of Science and Technology, Cairo, Egypt . ABSTRACT Single crystal silicon freestanding structures for tensile and fatigue testing were treated with KrF excimer laser to improve surface roughness and accordingly mechanical performance. Sample thickness was 5 μm. Localized laser treatment was successful in eliminating the scallops developed during Bosch process and in reducing surface roughness. Harsh irradiation at laser energies up to 4 J/cm 2 was only possible due to localized treatment without significant vibrations occurring on the freestanding samples that led to fracture in preliminary experiments at energies as low as 0.16 J/cm 2 . Finite element an...