Nucleation and growth analysis of microcrystalline silicon by scanning probe microscopy: substrate dependence, local structural and electronic properties of as-grown surfaces

Nucleation and growth of hydrogenated microcrystalline silicon films are in vestigated by scanning probe microscopy and spectroscopy of as-grown firms. We measure highly doped films grown on oxidized silicon and discuss nuclea tion of crystallites in comparison with hydrogen-passivated substrates. It turns out that the oxidized substrate mediates nucleation. This mechanism i s preferred over nucleation on hydrogenated amorphous silicon. For films as thin as a few nanometers we demonstrate that scanning tunneling microscopy and spectroscopy are capable of spatially resolving structural and electro nic surface properties. Amorphous and microcrystalline surface elements are distinguished by different types of tunneling spectra showing by a factor of similar to 5 a larger rectification for crystallites. (C) 2000 Elsevier Science B.V. All rights reserved.