Laser-induced lateral epitaxy in fully depleted silicon-on-insulator junctions

Abstract

Junction formation by laser-induced lateral epitaxy was studied on a fully depleted silicon-on-insulator substrate (25–30 nm Si on 375 nm silicon dioxide). Selective laser melting of amorphous films with a 35 ns 308 nm XeCl laser pulse was characterized in situ using transient conduction and optical reflectance techniques. Lateral epitaxy from a channel edge was observed for 146 nm after a 300 mJ/cm2 irradiation. The initial 28 nm of epitaxy was nearly defect free, followed by an increasing density of twins and ultimately terminating in an amorphous quench. The microstructure is discussed as a lateral equivalent of laser-induced amorphization of bulk Si.