Characteristics of Titanium Oxide Gate Nmosfet Formed by E-Beam Evaporation with Additional Rapid Thermal Oxidation and Annealing

High k insulators, such as titanium oxide, have been obtained by Ti e-beam evaporation, using different thicknesses of 5nm, 10nm and 20nm with additional rapid thermal oxidation and annealing at temperature of 960{degree sign}C for 40s. Characterization by Fourier transform infrared analyses reveals the Ti-O and Si-O bonds, which confirms titanium oxide formation. Raman spectroscopy identified that these films present rutile and anatase phases. nMOSFETs and MOS capacitors, with Al electrodes and final sintering at 450{degree sign}C for 10min in forming gas, were fabricated. MOS capacitors were used to obtain capacitance-voltage measurements, and to extract the Equivalent Oxide Thickness from the films, resulting in values between 16.3nm and 19.7nm, and effective charge densities of about 1011cm-2. nMOSFET electrical characteristics, such as threshold voltages between 0.39V and 0.43V and sub-threshold slopes between 61mV/dec and 100mV/dec, were obtained. These results indicated that the TiOx films are suitable gate insulators for MOS devices.