A new self-aligned quantum-well MOSFET architecture fabricated by a scalable tight-pitch process

We have developed a new III-V self-aligned Quantum-Well MOSFET (QW-MOSFET) architecture that features a scalable highly conducting ledge over the channel access region. The extensive use of RIE and digital etching techniques enables the precise design of the length and thickness of the ledge and allows the careful balancing of performance against short-channel effects. We demonstrate L_g=70 nm InAs MOSFETs with a ledge length of 5 nm that feature a record g_m of 2.7 mS/μm. Separately, devices with a ledge length of 70 nm yield a record ON-current of 410 μA/μm (V_dd=0.5 V and I_off=100 nA/μm). We also demonstrate working MOSFETs with L_g = 20 nm and a very tight metal contact spacing. Devices with a 5 nm ledge length reveal for the first time the existence of off-state leakage (GIDL) in III-V MOSFETs.