The growth of SiC high quality crystalline films is a subject of growing efforts bacause of its promising applications in semiconductor microelectronics for extreme environment and for blu emitting LEDs. Growth process still show severe limits with large defect densities and control on structure and morphology not yet adequate to prepare good quality films. As far as hetero-epitaxial growth is concerned it has been experimentally shown that the type of precursor, their concentrations and the substrate temperatures play an important role on both film morphologies and defect densities. Recently C60 has been proposed as precursor to lower reaction temperatures down to 850 C - 950 C. In this panorama our approach is based on the idea of using supersonic seeded beams so that the onset of the carbidization could be activated by the kinetic energy of the fullerene precursors reducing significantly the temperature of the process. Our novel source is a hyperthermal seedable supersonic beam (HSB), that allows a fine control on beam kinetic energy, up to 50 eV, as well as on beam flux. The film synthesis is investigated and monitored in situ by means of electron spectroscopies and LEED. The structure and morphology is then characterized in details by SEM, AFM and TEM with observations performed ex-situ. Structure, morphology and defct densities are shown to be strongly dependent on beam parameters that can be well controlled by the sources operating conditions so that quality of films can be controlled and improved significantly.
Hetero-Epitaxial Synthesis of SiC from C60 Seeded Supersonic Beams
CIULLO, Giuseppe;
1999
Abstract
The growth of SiC high quality crystalline films is a subject of growing efforts bacause of its promising applications in semiconductor microelectronics for extreme environment and for blu emitting LEDs. Growth process still show severe limits with large defect densities and control on structure and morphology not yet adequate to prepare good quality films. As far as hetero-epitaxial growth is concerned it has been experimentally shown that the type of precursor, their concentrations and the substrate temperatures play an important role on both film morphologies and defect densities. Recently C60 has been proposed as precursor to lower reaction temperatures down to 850 C - 950 C. In this panorama our approach is based on the idea of using supersonic seeded beams so that the onset of the carbidization could be activated by the kinetic energy of the fullerene precursors reducing significantly the temperature of the process. Our novel source is a hyperthermal seedable supersonic beam (HSB), that allows a fine control on beam kinetic energy, up to 50 eV, as well as on beam flux. The film synthesis is investigated and monitored in situ by means of electron spectroscopies and LEED. The structure and morphology is then characterized in details by SEM, AFM and TEM with observations performed ex-situ. Structure, morphology and defct densities are shown to be strongly dependent on beam parameters that can be well controlled by the sources operating conditions so that quality of films can be controlled and improved significantly.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
