Vertical p-type high-mobility heterojunction metal-oxide-semiconductor field-effect transistors

We have fabricated a vertical p-channel metal-oxide-semiconductor field-effect transistor called high-mobility heterojunction transistor (HMHJT). Compared with a Si control device, reduced short channel effects, reduced floating body effect, and high drive current have been achieved with this device structure. A SiGe/Si heterojunction barrier at the source/bulk junction suppresses drain induced barrier lowering and bulk punchthrough, which are significant problems for sub-100 nm devices. A SiGe source also helps to reduce the charge built-up in the floating body. The higher mobility in a strained SiGe channel and the absence of a hetero-barrier between the source and channel result in higher drive current. The fabricated HMHJT has a 60% higher drive current at V-DS=V-GS-V-T=-1.6 V, and a 70x lower off-state leakage current at V-DS=-1.6 V and V-GS=0.0 V, compared with the Si control device. (C) 2001 American Institute of Physics.