Innovative techniques for conformal doping of semiconductors for applications in micro- and nano-electronics

Abstract

This Ph.D. thesis is intended to provide a contribution to understanding some aspects of doping by MD through systematic experimental work. In chapter 1, in order to better understand this work, the main aspects of semiconductor properties, the techniques commonly used for doping these materials and the MD are briefly recalled. In chapter 2 some aspects of MD are discussed. In particular a physico-chemical characterization of molecular precursors in standard conditions, the role of the surface treatments and the role of the dilution of the precursor solution was examined. In chapter 3, the results about the role of the deposition parameters in MD are discussed, focusing on the role of coating time and sampling time and on the role of the solvent and the molecular precursor. Chapter 4 examines the results obtained by studying the effects of the post-deposition treatments. The following aspects are discussed in detail: the role of the annealing parameters: Temperature and time, the competition between evaporation and diffusion and the role of the cap layer. In chapter 5 an example of application of MD to Si nanowires are investigated. Finally, the results of this work and the perspectives of this activity are discussed and possible experimental approaches for the study of some unclear aspects in this thesis work are proposed. These aspects were studied by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), transmission electronic microscopy (TEM) and Raman Spectroscopy, electrical measurements were performed by spreading resistance profiles (SRP).