A Novel approach towards integration of VO$_{2}$ thin films on Si(100) for thermal switching devices applications

VO$_{2}$ exhibits a very interesting semiconductor to metal transition (SMT) as the crystal structure changes from monoclinic to tetragonal upon heating close to 68C. Parameters associated with SMT in VO$_{2}$ thin films, such as, transition temperature (T$_{t})$, hysteresis ($\Delta $H), transition width ($\Delta $T) and the order of magnitude change ($\Delta $A) are a strong function of microstructure, orientation, and stoichiometry. We have developed a novel method to produce epitaxial VO$_{2}$ thin films with controlled SMT characteristics and its integration with Si(100) substrate which is of immense technological importance due to a variety of sensor- and memory-type applications. We have optimized the deposition conditions for the growth of epitaxial VO$_{2}$ films on Si substrate using a pulsed-laser deposition method. The integration of VO$_{2}$ with Si was accomplished via domain matching epitaxy of TiN and MgO intermediate layers on Si. XRD and HR-XTEM studies were carried out and resistance measurements were done to quantify the SMT parameters as a function of microstructure and composition. We have established structure-property correlations and related to our phenomenological model based upon thermodynamics.