Growth and characterization of epitaxial 3C-SiC films on silicon for electronic applications

Silicon carbide is a material with a unique combination of properties that make it suitable for high temperature, high frequency and high power electronic applications. Among the wide band-gap semiconductors, it is the most technologically promising at this point in time. Growth of single-polytype, single crystal thin films on a suitable substrate is the key to the application of this material. This thesis explores (i) the issues connected with the growth of 3C-SiC epitaxial thin films on Si substrates by chemical vapor deposition and (ii) the role of void formation on the properties of the films.; Two different reactors have been used for growth and the differences in the films from these reactors was studied. A wide range of structural, chemical and electrical characterization techniques has been employed in this study in trying to elucidate the role of crystal quality on the subsequent properties. The formation of voids in the Si substrate at the SiC/Si interface in films during growth in one of the reactors is studied, in particular, and the influence of these voids on the electrical properties of the film have been demonstrated. A mechanism for the formation of voids is proposed and reasons for their absence in the films from the second reactor are suggested. An unusually high mobility, relative to other reported experiments, of 850 cm{dollar}sp2{dollar}/V-s at a carrier concentration of {dollar}rm 3 times 10sp{lcub}18{rcub}/cmsp3{dollar} has been measured in the films without voids. The theoretical estimates of electron mobility have been re-calculated using recent data. It is demonstrated that the measured mobilities can be explained using a space charge scattering mechanism. In addition, the stresses in the films were determined experimentally and correlated with possible mechanisms of stress generation.; Some preliminary work in understanding and developing suitable ohmic and Schottky contacts for high temperature electronics was done. The early results demonstrate some problems involved in fabricating these contacts, such as, contamination during metal deposition, etc. A high temperature probe station has been designed and built for the purpose of electrical characterization of contacts to temperatures of up to {dollar}{lcub}sim{rcub}500spcirc{dollar}C.