Tuning the Germanium TFET: Device Optimization for Maximum Ion

摘要

As MOSFET scaling has attained the 22 nm node, alternative concepts are intensively being investigated. The concept of the Tunneling Field Effect Transistor (TFET) is currently being explored as one of the device concepts most likely to enable energy efficient computation that, in addition, can potentially outperform the conventional MOSFET. We present a vertical device architecture grown with a solid source SiGe Molecular Beam Epitaxy (MBE) technique. The layer structure consists of a p+-i-n+ heterostructure. Layer growth by MBE enables us to realize abrupt heterojunctions and sharp doping profiles, which are key requirements for high TFET performance. For the Ge vTFET we used a special low temperature processing. With the improved growth of the TFET structure, we can achieve a high record Ion of 822 μA/μm at p-channel operation. This represents a considerable improvement over previous Ge (v)TFET devices. The Ion/Ioff ratio approaches three decades in p-channel mode.