X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF TIN FILMS PRODUCED WITH TETRAKIS(DIMETHYLAMIDO)TITANIUM AND SELECTED N-CONTAINING PRECURSORS ON SIO2

Low pressure chemical vapor deposition TiN films were produced on SiO2 by codosing tetrakis(dimethylamido)titanium (TDMAT) with selected N-c ontaining precursors. The films were grown at total pressures ranging from 10(-4) to 10(-3) Torr and temperatures between 523 and 773 K. Fil m composition and chemical states were determined, without exposure to ambient pressure, using x-ray photoelectron spectroscopy (XPS). Our p rimary goal was to evaluate how precursor ligands affect C and N incor poration into TiN films. To this end, methylhydrazine (MH), dimethylhy drazine (DMH), and 1-aminopiperidine (AP) were chosen for their steric differences, and t-butylamine (TBA) and aniline allowed us to assess how C and N incorporation are affected by the C-N bond in the aminolik e compounds versus the N-N bond in the hydrazinelike compounds. At all growth temperatures, a decrease in the carbon concentration and an in crease in the N concentration were observed for the MH and DMH cases w hen compared to TDMAT alone, while C content increased for aniline. AP caused only a slight reduction of C at temperatures of 673 K and abov e. Growth temperature affected film composition and the chemical state s of C, N, and Ti. At 623 K, DMH and MH reduced the C/Ti ratio from 1. 0 with TDMAT alone to 0.2, while aniline increased C/Ti to 2.0 and AP and TEA had little effect. The addition of the N-containing precursors causes the XPS C 1s peak to broaden and shift to higher binding energ y; the N 1s peak also broadened, suggesting that, compared to TDMAT al one, more C-N bonds are formed. Furthermore, the Ti 2p peak shifted to higher binding energy and became broader upon codosing, suggesting th e incomplete conversion of Ti (IV) to Ti (III) in the TiN film. Postdo sing with MH and DMH supports the conclusion that surface reactions oc cur between TDMAT and the hydrazinelike precursors. (C) 1998 American Vacuum Society.