Thermal Chemistry of Tetrakis(ethylmethylamido)titanium on Si(100) Surfaces

The thermal chemistry of tetrakis(ethylmethylamido)titanium (TEMAT) on (100)-oriented surfaces of silicon wafers was studied by using infrared absorption and X-ray photoelectron spectroscopies. Dissociative adsorption was identified starting at temperatures around 450 K, likely limited by the rate of an initial elimination of some of the amido groups. That adsorption is rapidly followed by a selective beta-hydride elimination reaction from the ethyl moiety of the remaining ligands to produce N-methylethylidenimine adsorbed species. Long exposures of the Si(100) surface to TEMAT above the temperature of decomposition lead to the growth of a metal nitride film. Those films appear to grow in 3-D fashion, and contain high levels of C and O contaminants.