Nucleation mechanism of hydrogen-induced platelets in single crystal and polycrystalline silicon

Abstract

Hydrogen passivation of polycrystalline silicon (poly-Si) and single-crystal silicon (c-Si) at moderate temperatures causes the generation of platelets. These two-dimensional extended structural defects appear within 1500Å of the surface and are predominantly oriented along {111} crystallographic planes. Platelet formation is observed only for Fermi energies of EC−EF⩽0.3eV. As the Fermi level moves closer to the conduction band the platelet concentration increases monotonically. It is demonstrated experimentally that platelet generation is driven by the Fermi energy. Based on our data we propose a model for platelet nucleation and growth that is consistent with experimental and theoretical studies of hydrogen in silicon.