Deep insights into low frequency noise behavior of tunnel FETs with source junction engineering

The low frequency noise (LFN) mechanisms of TFETs with different source junction design are experimentally studied for the first time, including the random telegraph signal (RTS) noise. Different from MOSFET, due to the non-local band-to-band tunneling (BTBT) mechanism and small LFN-generating area, both 1/f and 1/f2 LFN dependence can be observed in large TFETs with large device to device variability, as well as high noise. It is found that the “active” traps responsible for the noise mechanism are located in the area where electron-hole pairs generated by non-local BTBT, and the trap located at the maximum junction electric field tends to have relatively weak impacts on the TFET noise. With new abrupt tunnel junction design, it is observed that the device variability can be effectively alleviated with much lower noise level. In addition, a single-trap-induced RTS noise in TFETs with different source junction design is also experimentally investigated. New features, including strong VD dependence of RTS parameters and significantly high amplitude (~28%), indicate the desirable requirement for the source junction optimization in TFETs.