Abstract
A novel tunneling field-effect transistor (TFET) with an L-shaped Ge source is investigated. The device comprises a Ge source that extends underneath a Si-channel region and separated from the drain by an insulator (SiO2). By optimizing the overlap length of the extended source LOV and the Si body thickness TSi, the current due to vertical band-to-band tunneling (BTBT) of the Ge–Si hetero-junction could be increased significantly and is scalable with LOV. This leads to higher ION and improved S. The SiO2 also reduces OFF-state current IOFF by blocking leakage paths. With extensive simulation, the device physics and design guidelines of this novel structure are outlined.