Structural and electrical characterization of TiO2 grown from titanium tetrakis-isopropoxide (TTIP) and TTIP/H2O ambients

Abstract

Thin films of TiO2 have been deposited on silicon wafers from titanium tetrakis-isopropoxide (TTIP) and TTIP/H2O using low pressure metalorganic chemical vapor deposition. The films have been characterized by Rutherford backscattering spectrometry, forward recoil spectrometry, x-ray diffraction, and electrical techniques. Dielectric constants of approximately 30 were measured by high frequency C–V. Metal–oxide–semiconductor capacitors were fabricated using sputtered platinum as the upper electrode material. Films deposited in the presence of water vapor had a much lower quality interface with the silicon substrate. Normal thermionic emission was observed when the gate electrode was positively biased and barrier heights were extracted. Dramatically reduced leakage currents and increased barrier heights were seen after 750 °C anneals in dry oxygen. Using a ramped voltage test, capacitors were found to break down at applied fields of 3.0 MV/cm.