TCAD Design of Tunnel FET Structures and Extraction of Electrical Characteristics

Silicon dioxide (SiO 2) or silica is a metal oxide which comes under fourth group. The properties of SiO 2 includes high thermal stability, good abrasion resistance and good electrical insulation. It is the most commonly used dielectrics in semi- conductor arena. Hafnium oxide (HfO 2) comes under the group of high-k dielectrics. This inorganic compound, which is also known as hafnia acts as a replacement for conventional silicon dioxide dielectric layers. In this paper, we have simulated TFET structures with hafnia and silica as dielectric materials. A considerable increase in capacitance, of around 58 %, was obtained when we changed the dielectric material from silica to hafnia. The dimensions of dielectric layer was kept constant during the simulations. The gaussian doping distribution is very much similar to real doping profiles and is simple in structure. So we adopted gaussian doping profile for source and drain doping. The simulations results showed that TFET structures with SiO 2 dielectric layer exhibited better transfer characteristics than TFET structures with HfO 2 dielectric layer.