Chemical vapour deposition group 2 compounds

Applications involving ring transfer or loss. The kinetic lability, volatility, and Lewis acidity of heavy alkaline earth metallocenes have been the properties most important to their applications. The gas-phase decomposition of volatile metallocenes is useful in the preparation of thin films of alkaline earth-containing materials and in doping semiconductors. Reviews are available on the use of group 2 organometallic compounds as precursors for chemical-vapour deposition (CVD).2 3... 

Binary and Ternary Compounds with Elements of Groups II, III, and V. 2f-ray electron spectroscopy has been used to probe the electronic structures of tungsten borides, nitrides and also some carbides and oxides. Enthalpies of formation AH°298.i5 the tungsten borides WB and W2B have been determined by fluorine calorimetry and are — 66.5 and — 68.2 kJ mol respectively. The theoretical possibilities of preparing M02B, a-MoB, MO2B5, WjB, a-WB, and W2B5 by chemical vapour deposition is discussed and MoXj (X = B or Be) have been prepared and examined by X-ray methods. ... 

Oxides, Hydroxides, and Sulphides.—Chemical vapour deposition at 300 °C from Fe(tfac)3 (tfac = trifluoroacetylacetonate) gives p-FCjOj of the same structure as that formed by the hydrolysis of FeClg.bHjO. 2Fe203,S03,mH20 (m > 6) has been found to be amorphous and it is suggested that as there are no OH groups present, the compound should be considered as a hydrated iron(iii) oxide sulphite. A comprehensive study of ordered and disordered Scheelite-related Bi3(Fe04)(Mo 04)2 has been made. ... 

A few compounds have been studied for other reasons. These include trimethylaluminium [64] and trimethylgallium [65] which are of interest because of their use in metal organic chemical vapour deposition (MOCVD) processes. The compounds were also studied because the interactions between methyl groups in the same molecule are a continuing source of fascination. Tetramethyltin was studied for the same reason [66]. 

Complexes of this type may contain a variety of orgaiuc residues R, such as alkyl, vinyl, alkynyl or aryl. The neutral donor group L is most commonly a tertiary phosphine or an isocyanide ligand, and polynuclear complexes with bridging polyfunctional donor ligands are also known . From a practical point of view, the series of organogold(I) and isocyanide complexes is of particular interest since some of its members hold promise as precursors for the chemical vapour deposition of gold films. A selection of these and other compounds of the type [RAuL] is presented in Tables 1-3. 

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