Grain boundaries in p-n junction diodes fabricated in laser-recrystallized silicon thin films

Abstract

Grain boundaries intersecting metallurgical p‐n junctions have been evaluated in laser‐recrystallized silicon thin films. Lateral p‐n junction diodes were fabricated in islands of polycrystalline silicon which were defined on an amorphous substrate and cw laser recrystallized. The oxide‐passivated diodes display good current rectification. Correlated scanning electron microscopy (electron‐beam induced current and voltage contrast) and transmission electron microscopy reveal that the electrical junction strongly deviates from the linear boundary between the n and p regions defined by ion implantation. Spikes in the junction profile arise from enhanced dopant diffusion along grain boundaries.