Metal oxide semiconductor (MOS) device down-scaling is a powerful driving force for the evolution of microelectronics. The downsizing rate of metal oxide semiconductor field effect transistors (MOSFETs) is really marvelous. Silicon dioxide (SiO 2 ) has served as a perfect gate dielectric for the last four decades. Due to physical limitations, leakage current, high interface trap charge it now needs to be replaced with higher permittivity dielectric material. Keeping the motivation for the search of high-k materials, extensive studies have been carried out on several metal oxides, such as ZrO
Although scaling will continue for couple of decades but device geometries reaches to atomic size and limitation of quantum mechanical physical boundaries. To address these problems there is need of innovation in material science & engineering, device structure, and new nano devices based on different principle of physics. So TiO 2 thin films have been grown on well clean N-type silicon substrates via a sol-gel spin coating method. MOS capacitor were fabricated and characterized with SiO 2 and TiO 2 as dielectric material on N-type silicon wafer. The thickness was measured by stylus profiler and found to be 510 Å and 528 Å for SiO 2 and TiO 2 respectively. Some of the material parameters were found from the measured Capacitance -Voltage (C-V) curve obtained by SUPREM-III (Stanford University Process Engineering Model Version 0-83) for SiO 2 and C-V Keithly 590 analyzer for TiO 2 thin films. The result shows that obtained TiO 2 film present a dielectric constant of approximately 80. The refractive index was found to be 2.4 and optical constant was 5.43 obtained from Ellipsometry. Band gap 3.6 eV of TiO 2 was calculated by spectrophotometer and Surface morphology was obtained using Scanning Electron Microscope (SEM-JEOL) micrograph. The aluminum (Al) metal was deposited by the thermal evaporation system on the back side of the sample for the ohmic contact. Analysis shows that TiO 2 may be acceptable as a viable substitute for high k dielectric in order to prevent the tunneling current problems.
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