High k dielectric metal oxide films have attracted much attention as promising candidates in place of SiO2. The use of high –k/metal gate technology will provide cost, performance and power savings. To increase the capacitance while reducing the tunneling current, various kinds of high dielectric materials have been investigated as possible alternatives to SiO2. Owing to handle high critical electric field, electron saturation velocity and thermal conductivity SiC has advantages over Si, quantitatively put together 186 times better than Si. In this work, we have studied the low leakage electrical properties of nano HfO2 thin films on SiC. The bandgap of HfO2 thin films was observed to be 5.8 eV. The chemical nature and stoichiometry of the films were analyzed by XPS. MIS structures (CrSi2/SiC/HfO2/Ni) with Ni as a top electrode and CrSi2 as a bottom electrode were fabricated to study the leakage current properties. The devices exhibited leakage current density of 30 nA/cm2. The leakage properties of the MIS junctions are studied for elevated temperatures in the range of 50-300C. The dielectric constant of these films is estimated to be in the range of 17-24 from C-V measurements. The frequency dependence of the interface trapped charges is studied.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: June 18, 2012
Pages: 91 - 93
Industry sector: Sensors, MEMS, Electronics
Topics: Energy Storage