Interfacial charge analysis and temperature sensitivity of germanium source vertical tunnel FET with delta-doped layer

Abstract

The influence of interface trap charges (ITCs) and reliability of the Germanium source vertical tunnel field effect transistor with delta-doped layer (GSDD vTFET) is investigated in this paper. The analysis is carried out on the GSDD vTFET by evaluating the analog/RF performances under the consideration of donor and acceptor ITCs and temperature variations. The presence of interface trap charges at the silicon channel/gate oxide interface changes the flat-band voltage, affecting the analog and RF performances of the GSDD vTFET. The study is carried out at distinctive donor and acceptor interface trap charges. The findings indicate that as the interface trap charge densities increases, the device's output changes drastically. The off-state current of the GSDD vTFET deteriorates significantly from an order of 10−14 A to 10−8 A in the presence of positive ITC of 1012/cm2. The temperature variations over a wide range shows that OFF-state current as well as subthreshold region gets deteriorated due to dominance of Shockley–Read–Hall effect and the superthreshold region is less affected owing to dependence of band-to-band tunneling. The results reveal that when the temperature is raised from 200 K to 400 K, the ION/IOFF current ratio degrades tremendously from ~1014 to ~108 in the existence of donor ITC. It is also observed that the GSDD vTFET is less susceptible to acceptor interface trap charge in comparison with donor ITC in a temperature sensitive environment. Quantum correction (QC) of GSDD vTFET with ITC shows the same type of variations as the condition without considering QC.