Atomic Layer Deposition of Tin Monosulfide Using Vapor from Liquid Bis(N,N'-diisopropylformamidinato)tin(II) and H2S

Applications of low-valent compounds with heavy group-14 elements

Over the last two decades, the low-valent compounds of group-14 elements have received significant attention in several fields of chemistry owing to their unique electronic properties. The low-valent group-14 species include tetrylenes, tetryliumylidene, tetrylones, dimetallenes and dimetallynes. These low-valent group-14 species have shown applications in various areas such as organic transformations (hydroboration, cyanosilylation, N-functionalisation of amines, and hydroamination), small molecule activation (e.g. P4, As4, CO2, CO, H2, alkene, and alkyne) and materials. This review presents an in-depth discussion on low-valent group-14 species-catalyzed reactions, including polymerization of rac-lactide, L-lactide, DL-lactide, and caprolactone, followed by their photophysical properties (phosphorescence and fluorescence), thin film deposition (atomic layer deposition and vapor phase deposition), and medicinal applications. This review concisely summarizes current developments of low-valent heavier group-14 compounds, covering synthetic methodologies, structural aspects, and their applications in various fields of chemistry. Finally, their opportunities and challenges are examined and emphasized.

SnO via Water Based ALD employing Tin(II) Formamidinate: Precursor Characterization and Process Development

Tin monoxide (SnO) is a promising oxide semiconductor which is appealing for a range of applications ranging from channel materials in p-type field effect transistors (FET) to electrode materials searched...

A study on the influence of ligand variation on formamidinate complexes of yttrium: new precursors for atomic layer deposition of yttrium oxide

The synthesis and characterization of a series of closely related Y(III) compounds comprising the formamidinate ligands (RNCHNR) (R = alkyl) is reported, with the scope of using them as prospective precursors for atomic layer deposition (ALD) of yttrium oxide (Y₂O₃) thin films. The influence of the side chain variation on the thermal properties of the resulting complexes is studied and benchmarked by thermal analysis and vapor pressure measurements. Density functional theory (DFT) studies give theoretical insights into the reactivity of the compounds towards water, which was targeted as a co-reactant for the deposition of Y₂O₃via thermal ALD in the next step. Among the four complexes analyzed, tris(N,N'-di-tert-butyl-formamidinato)yttrium(III) [Y(^tBu₂-famd)₃] 1 was found to possess enhanced thermal stability and was selected for Y₂O₃ ALD process development. A broad ALD window ranging from 200 °C to 325 °C was obtained, yielding films of high compositional quality. Furthermore, with a film density of (4.95 ± 0.05) g cm^-1 close to the bulk value, polycrystalline fcc Y₂O₃ layers with a smooth topography resulted in promising dielectric properties when implemented in metal insulator semiconductor (MIS) capacitor structures.

Synthesis, Characterization, and Thermal Study of Divalent Germanium, Tin, and Lead Triazenides as Potential Vapor Deposition Precursors

Only a few M-N bonded divalent group 14 precursors are available for vapor deposition, in particular for Ge and Pb. A majority of the reported precursors are dicoordinated with the Sn(II) amidinates, the only tetracoordinated examples. No Ge(II) and Pb(II) amidinates suitable for vapor deposition have been demonstrated. Herein, we present tetracoordinated Ge(II), Sn(II), and Pb(II) complexes bearing two sets of chelating 1,3-di-tert-butyltriazenide ligands. These compounds are thermally stable, sublime quantitatively between 60 and 75 °C (at 0.5 mbar), and show ideal single-step volatilization by thermogravimetric analysis.