Reductive Eliminations from Amido Metal Complexes: Implications for Metal Film Deposition

The thermal decomposition of tetrakis(dimethylamido)titanium (TDMAT) follows a number of competitive reactions, including not only the known hydrogenation and β-hydride elimination steps, to produce dimethylamine and N-methylmethaneimine respectively, but also a reductive elimination to yield tetramethylhydrazine and a more complex conversion to N,N,N'-trimethyldiaminomethane and N,N,N',N'-tetramethyldiaminomethane. The latter reactions may account for the reduction of the metal when these compounds are used for the atomic layer deposition (ALD) of metal nitride films. Similar reactions take place with tetrakis (ethylmethylamido)titanium (TEMAT) and with pentakis(dimethylamido)tantalum (PDMAT).