| The chemical vapor deposition (CVD) of boron phosphide (BP), boron nitride (BN), and tungsten nitride (WNx) thin films onto a variety of substrates was investigated. The purpose of the BP and BN studies was to study the viability of depositing and stabilizing the cubic phase of boron nitride (cBN). Tungsten nitride growths were conducted to determine the suitability of novel imido precursors for copper/silicon diffusion barrier applications.; Thermodynamic models of various BP, BN, and GaN based systems were developed using BCl3-PCl3-H2, BCl3-NH 3-H2, and Ga-N as reactants, respectively. Results revealed conditions leading to many solid phase domains including BP, cBN, and GaN. Reactant ratios were systematically varied and the influence of HCl and an inert gas (He) was studied. Phase diagrams generated for the strained Ga-N system showed the profound influence of lattice mismatch induced strain energy on a system's thermodynamic equilibrium.; The CVD of cubic BP thin films from BCl3, PCl3, and H2 reactants onto silicon, sapphire, diamond, silicon carbide, and nickel substrates revealed a kinetically controlled growth process. Characterization revealed roughly spherical island coalescence growth and little contamination. The BP films were then in-situ nitrided using NH3 diluted in a H2 carrier gas stream in an attempt to obtain cubic BN using the underlying cBP template. Attempts by five other researchers produced contradictory results with film characterization limited mostly to X-ray diffraction (XRD). A much wider array of deposition conditions and analysis techniques were used to characterize films in this study. Results indicate that cBN stabilization may be possible using in-situ cBP nitridation. These are the first results ever confirmed using multiple characterization techniques.; Metal-organic CVD (MOCVD) of tungsten nitride thin films was also investigated. Results using a solid-source delivery system were unsuccessful because of the low vapor pressure and poor thermal sublimation profiles of each precursor. Film growths using an ultrasonic delivery system, where the precursors are dissolved into a solvent and injected into the reactor in a nebulized mist, proved to be more successful. Low resistivity WNx films deposited at low temperature were obtained. A U.S. patent application has been submitted as a result of this work. |
