Ti Source Precursors for Atomic Layer Deposition of TiO2, STO and BST

In this study we evaluated several precursors such as tetrakis(dimethylamino) titanium (TDMAT), tetrakis (diethylamino) titanium (TDEAT), tetrakis(ethylmethylamino) titanium (TEMAT) along with novel PrimeTiTM, StarTiTM and TyALDTM for TiO2 ALD application with both water and ozone as the oxidizer. Each precursor is evaluated with respect to some of the important characteristics like growth rate of TiO2 per ALD cycle, range and upper limit of process temperature window, volatility and stability of precursor, chemistry with desired oxidizer etc., that are critical for the selection of the precursor. All amino-compounds had a narrow process window. Precursor decomposition was observed for TDMAT, TDEAT and TEMAT at temperature higher than 225 oC limiting the deposition process at 225 {degree sign}C. On the other hand, TiO2 ALD using PrimeTiTM and StarTiTM is observed up to 325 and 400 {degree sign}C respectively. Finally, photoelectron spectroscopy analysis of some the films will be discussed.