Chemical vapor deposition (CVD) is a well-developed technique for growing thin films of a wide variety of materials, which relies on the development of new and better performing metal-organic precursors. To this end, three studies have been conducted into the compatibility of sulfur and phosphine containing ligands with low- and high-valent transition metals to develop precursors for thin film growth. First, bis(di(2,2,2-trifluoroethyl)dithiocarbamato)copper(II) (1.1) has been synthesized, fully characterized, and implemented for the deposition of high quality cuprous sulfide thin films on amorphous glass substrates by metal-organic (MO) CVD. Thermogravimetric analysis (TGA) shows improved volatilization and mass transport of the precursor due to fluorination of the ligand framework. Films deposited in the presence of O2 at 350 0C are phase-pure polycrystalline Cu1.96S with p-type conductivity of 68 S/cm and an optical band gap of 1.8 eV. Next, MoS2 thin films have been deposited onto 52100 steel substrates by aerosol-assisted (AA) CVD using the metal-organic precursor tetrakis(diethyldithiocarbamato)molybdenum(IV) (2.1). Film analysis indicates growth of an initial, highly crystalline FeS layer exhibiting preferred orientation parallel to the substrate, followed by growth of MoS2 nanoparticles. Friction coefficients for MoS2-coated steel specimens reach 0.10 when tested at 100 0C in air. Codeposition by AACVD of tetrakis(tert-butylthiolato)titanium(IV) (2.2) with complex 2.1 yields nanoparticle films of variable TiO2 content as a result of solvent decomposition on the MoS2 surface and oxidation of TiS2. Finally, a series of light- and air-stable tris(phosphino)borato silver(I) complexes has been synthesized, structurally and spectroscopically characterized, and implemented in the growth of low resistivity metallic silver thin films by AACVD. One member of the series, [nBuB(CH2PPh2)3]AgPEt3 (3.2), represents a significant improvement over previously available non-fluorinated Ag precursors, owing to ease of handling and efficient film deposition characteristics. TGA shows that the thermolytic properties of these complexes can be significantly modified by altering the ligand structure. Polycrystalline cubic-phase Ag thin films were grown on glass, MgO(100), and 52100 steel substrates. Ag films of thicknesses 3 μm, grown at rates of 14-18 nm/min, exhibit low levels of extraneous element contamination by x-ray photoelectron spectroscopy (XPS). Film growth proceeds primarily via an island growth (Volmer-Weber) mechanism.

Last modified

• 08/29/2018

Creator

• Matthew McCain

DOI

• https://doi.org/10.21985/N20H8Q

Subject

• Chemistry

Keyword

• Inorganic Chemistry

Date created

• 2007-12-13

Resource type

• Dissertation

Rights statement

• In Copyright