Papers by Author: Fernanda Chiarello Stedile

Abstract: This work provides data corroborating the presence of silicon oxycarbides (SiO_xC_y) in the SiO₂/SiC interface region. Besides, it presents results on the efficiency of hydrogen peroxide annealings for reducing the SiO₂/SiC interfacial region thickness. Finally, influences of water vapor thermal treatments on dielectric films thermally grown are presented. In most of the samples, isotopes rare in nature (¹⁸O and ²H) were used in thermal treatments associated with ion beam analyses.

Abstract: The effect of sequential thermal treatments with growth/removal steps of SiO₂ films intercalated with hydrogen peroxide treatments on the SiO₂/4H-SiC interfacial region thickness were investigated on both Si and C faces. In the Si face case, samples that were submitted to more H₂O₂ treatments presented thinner interfacial region thicknesses. In the C face case, on the other hand, no significant alteration in this region was observed.

Abstract: The consequences of thermal treatments in nitric oxide atmospheres on the characteristics of dielectric films / SiC structures was investigated by high-frequency capacitance-voltage measurements, X-ray photoelectron spectroscopy, and X-ray reflectometry techniques. It was observed that nitrogen incorporation in dielectric films / SiC structures leads to the formation of a thinner interfacial layer that contains carbon. This fact was related to the improvement of electrical properties of those structures.

Abstract: The mechanisms of oxygen incorporation during dry thermal oxidation of 6H-SiC wafers were investigated. Isotopic tracing of oxygen was performed by sequential oxidations in dry O2 enriched or not in the 18O isotope and subsequent determinations of the 18O profiles. The results obtained with SiC substrates were compared with those of Si, evidencing different mechanisms of oxygen incorporation and transport. The gradual nature of the SiO2/SiC interface was also evidenced. A probable explanation for this gradual SiO2/SiC interface is shown to be the formation of C clusters during oxidation.