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

Hydrogen passivation of polycrystalline silicon (poly-Si) and single-crysta l silicon (c-Si) at moderate temperatures causes the generation of platelet s. These two-dimensional extended structural defects appear within 1500 Ang strom of the surface and are predominantly oriented along (1 1 1) crystallo graphic planes. Platelet formation is observed only for Fermi energies of E -C - E-F less than or equal to 0.3 eV. As the Fermi level moves closer to t he conduction band the platelet concentration increases monotonically. It i s demonstrated experimentally that platelet generation is driven by the Fer mi energy. Based on our data we propose a model for platelet nucleation and growth that is consistent with experimental and theoretical studies of hyd rogen in silicon. (C) 1999 Elsevier Science B.V. All rights reserved.