Characterization of laser-annealed Si layers by ellipsometry

Abstract

Ellipsometry has been used to investigate the effect of laser annealing on the ⁷⁵As⁺-implanted layers of single crystal and polycrystalline Si by Q-switched Nd: YAG laser. Recovery of implantation-induced changes in optical constants by laser irradiation has been measured, and compared with observation by electron diffraction analysis and electrical measurement. Epitaxial regrowth of the layer implanted to 10¹⁶/cm² occurs above 2–3 J/cm² incident energy density. Good correlation has been obtained between the results by different analytical techniques. The threshold energy density for recrystallization decreases with increasing the implant dose due to increase in the absorption coefficient of the implanted surface layer. It has also been shown that implanted CVD polycrystalline Si layer can grow epitaxially on Si substrate by laser annealing.