SYNTHESIS OF POROUS SILICON BY ION IMPLANTATION

Porous materials have attracted remarkable concerns and found tremendous impor- tance widespread in both fundamental research and industrial applications. Such materials could be widely used for variety applications as absorbents, lightings, catalysts, and for biologi- cal molecular filtration and isolation. One quite known method for preparation of porous semi- conductor structures is ion implantation, which was successfully used to create porous germa- nium layers by Ge + -, Bi + - and Sn + -ion irradiation of crystalline germanium substrates. It was also shown that ion implantation suited to produce porous structures in amorphous germanium and SiGe (90% of germanium) alloys thin films. Ion implantation is a well established and all over the world accessible technique, being mainly used for semiconductor microelectronic device fabri- cation. Unfortunately, a possibility about porous silicon (PSi) fabrication using ion implantation was not completely studied now. At the present report a novel technological approach based on low-energy ion implantation is suggested and realized to create PSi layers on the crystalline surface of Si wafers. It is demon- strated that using high-dose (more than 1.0m 10 16 ion/cm 2 ) Ag-ion implantation of silicon with the energy of 30 keV the surface PSi structures with nanoparticles can be successfully fabricated.