Synthesis And Characterization Of Precursors For Chemical Vapor Deposition Of Metal Oxide Thin Films

Material synthesis by the transformation of organometallic compounds (precursors) by vapor deposition techniques such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) has been in the forefront of modern day research and development of new materials. There exists a need for new routes for designing and synthesizing new precursors as well as the application of established molecular precursors to derive tuneable materials for technological demands. With regard to the precursor chemistry, a most detailed understanding of the mechanistic complexity of materials formation from molecular precursors is very important for further development of new processes and advanced materials. To emphasize and stimulate research in these areas, this volume comprises a selection of case studies covering various key-aspects of the interplay of precursor chemistry with the process conditions of materials formation, particularly looking at the similarities and differences of CVD, ALD and nanoparticle synthesis, e.g. colloid chemistry, involving tailored molecular precursors.

The synthesis and characterization of a new magnesium MOCVD precursor, Mg(dpm)2(TMEDA) is detailed. It is shown that the donating ligand TMEDA prevents oligomerization and subsequent volatility depression as observed in the commonly used [Mg(dpm)2]2. The superiority of Mg(dpm)2(TMEDA) as an MOCVD precursor is explicitly demonstrated by growth of epitaxial MgO thin films on single-crystal SrTiO3 substrates.

Nanomaterials via Single-Source Precursors: Synthesis, Processing and Applications presents recent results and overviews of synthesis, processing, characterization and applications of advanced materials for energy, electronics, biomedicine, sensors and aerospace. A variety of processing methods (vapor, liquid and solid-state) are covered, along with materials, including metals, oxides, semiconductor, sulfides, selenides, nitrides, and carbon-based materials. Production of quantum dots, nanoparticles, thin films and composites are described by a collection of international experts. Given the ability to customize the phase, morphology, and properties of target materials, this “rational approach to synthesis and processing is a disruptive technology for electronic, energy, structural and biomedical (nano)materials and devices. The use of single-source chemical precursors for materials processing technology allows for intimate elemental mixing and hence production of complex materials at temperatures well below traditional physical methods and those involving direct combination of elements. The use of lower temperatures enables thin-film deposition on lightweight polymer substrates and reduces damage to complex devices structures such as used in power, electronics and sensors. Discusses new approaches to synthesis or single-source precursors (SSPs) and the concept of rational design of materials Includes materials processing of SSPs in the design of new materials and novel devices Provides comprehensive coverage of the subject (materials science and chemistry) as related to SSPs and the range of potential applications

Four novel diamine adducts of bis(hexafluoroacetylacetonato)zinc [Zn(hfa)2·(diamine)] can be synthesized in a single step reaction. Single crystal x-ray diffraction studies reveal monomeric, six-coordinate structures. The thermal stabilities and vapor phase transport properties of these complexes are considerably greater than those of conventional solid/liquid zinc metal-organic chemical vapor deposition (MOCVD) precursors. Of the four complexes, bis(1,1,1,5,5,5-hexafluoro-2,4-pentadionato)(N,N '-diethylethylenediamine)zinc [Zn(hfa)2 ( N,N'-DEA)], is particularly effective in the growth of thin films of the transparent conducting oxide Zn- and Sn-doped In2O3 (ZITO) due to its superior volatility and low melting point of 64°C.