Insights into the Buried-Metal-Layer Impact on GIDL and ON-State Characteristics in Junctionless Transistor

The present work investigates the OFF-state lateral band-to-band-tunneling (L-BTBT) phenomena in a buried-metal-layer (BML) based junctionless (JL) FET (BML-JL-FET). The impact of BML-workfunction and BML-voltage on the L-BTBT component of the gate-induced-drain leakage (GIDL) is studied via the 2-D TCAD simulations. The nature of Schottky junction formed at the bottom of the semiconductor device layer has also been investigated. We observe that the sufficiently high BML-work function, or high BML-work function with negative voltage, allows for excessive band bending at the bottom Si/BML interface, resulting in the accumulation of the opposite charge carriers (holes). If BML is not optimized, this accumulated holes contribute adversely to the L-BTBT current component of the device. In addition, the impact of BML acting as a secondary gate on the device characteristics has also been studied.