Tin Compounds For CVD

Our first example that attempts to imravel this complexity is entitled Gas-Phase Thermochemistry and Mechanism of Organometallic Tin Oxide CVD Precursors . The authors, M. Allendorf and A.M.B. van Mol, describe the development of quantum chemistry methods that can predict heats of formation for a broad range of tin compounds in the gas phase, which need to be considered when Sn(CH3)4 or (CH3)2SnCl2 and other tin alkyls are used as precursors together with oxygen and water for tin oxide deposition. 

A different type of gas-phase chemistry has also been explored for simple germanium, tin and lead compounds, namely that induced by radiolysis. While germanium compounds have been the main targets and modeling of CVD processes the ultimate goal, radiolysis involves reactions of transient neutral and ionic species for which the overall mechanism is not always clear. On the other hand, analysis of the ultimate solid products252 obtained from radiolysis of different mixtures provides an exciting approach towards the synthesis of polymers and thin films. 

Titanium tetrakis(dialkylamide) compounds, Ti(NR2)4 (R= Me, Et, n-Pr, n-Bu) have been investigated in the CVD of TiN [144, 154-161]. Their decomposition, carried out in the presence of NH3(g), proceeds under relatively mild conditions and yields TiN films of good quality. Other precursors which have been used for the CVD of TiN include cyclopentadienyl-cycloheptatrienyl titanium, CpTi(C7H7) (15) [161], f-BuTi(NMe)3 [156, 161], [Ti(/i-N-r-Bu)(NMe2)2]2 (16) [156, 161] and Ti(f-BuDAD)2, bis(N,N -di-t-butyl-l,4-diaza-l,3-butadiene) titanium (17) [161]. The mixed amide... 

In solvated metal atom dispersion (SMAD) method solvated atoms prepared at very low-temperature are used as transient, highly reactive organometallic reagent for the deposition of Sn-Pt bimetallic particles onto different supports. In another approach chemical vapor deposition (CVD) using tin organometallic compounds was applied. For example, the selective reaction of Sn(CH3)4 vapour with Pt nanoparticles supported on Si02 appears to be very promising preparation method. 

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