Metallo-organic precursors

Thermal activation which typically takes place at high temperatures, i.e., >900°C, although the temperature can also be lowered considerably if metallo-organic precursors are used (MOCVD). 

Most metals can be deposited by MOCVD and in some cases the process is an important industrial operation. The metals most readily deposited by MOCVD are the non-transition metals. The following is a summary of the metallo-organic precursors and deposition condition presently used in development or production. 

Hoffman, D. M., et al., Plasma-Enhanced CVD of Silicon Nitride Films from a Metallo-Organic Precursor, J. Mater. Res., 9(12) 3019-3021 (1994)... 

Deposition at low temperature (200 00°C) is possible by plasma-CVD from the reaction of ammonia and a metallo-organic precursor tetrakis(dimethylamido)silicon, Si(NMe2)4. The films are essentially featureless. 

Vest, R. W. Xu, J. 1988. PbTi03 films from metallo-organic precursors. IEEE Trans. UFFC. 35 711-717. 

Solution-Liquid-Solid (SLS) growth of semiconductor nanowires by Wang etal. (2006). The synthesis proceeds by a solution-based catalysed growth mechanism in which nanometer-scale metallic droplets catalyse the decomposition of metallo-organic precursors and crystalline nanowire growth. 

With the seventh chapter, we move away from CVD. M.A. Malik and P. O Brien present a review of Organometallic and Metallo-Organic Precursors for Nanoparticles . Nanoparticles have been recognized as suitable systems for studying the transition from the molecular to the macrocrystalline level and exhibiting imusual chemical and physical properties. They have thus been... 

FIGURE 27.3 Examples of metallo-organic precursors commonly used in the fabrication of ferroelectric perovskite thin fihns (a) zirconium butoxide butanol (b) schematic of the 2-methoxyethoxy ligand bonded to a metal center (c) barium acetate (d) the acac ligand and (e) the mixed-ligand precursor titanium bis-acac diisopropoxide. After Schwartz et ah ... 

The thermal CVD process in which thermal energy in the form of heat is used to activate the reaction process is the most common one used. Thermal activation typically occurs at temperatures above 900°C but can be substantially lower when metallo-organic precursors are used. Thus, the coating/film produced by this technique must be thermally stable at such temperatures and the thermal activation process should not lead to the incorporation of unwanted species. 

Metallo-Organic CVD (MOCVD)I l It is possible to lower the deposition temperature of titanium carbide (i.e., 700°C) by using metallo-organic precursors such as ... 

In this work we prepare TiOj-SiO, gels starting from metallo organic precursors. The TiO, contents ranged from 0 to 10 mole %. The use of ultrasound to promote gelling, and the effect of different drying treatments on the structure and texture of the products are the... 

Vest, R. W. Electronics Films from Metallo-organic Precursors. J. B. Wachtmanand R. A. Haber (Eds.), Ceramic Films and Coatings, Noyes Publications, Park Ridge, pp. 303-341 (1993). 

Several carbohydrate-based metallo-organic precursors were developed... 

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