| 摘要 |
Non-planar Metal Oxide Field Effect Transistors (MOSFETs) and methods for making non-planar MOSFETs with asymmetric, recessed source and drains having improved extrinsic resistance and fringing capacitance. The methods include a fin-last, replacement gate process to form the non-planar MOSFETs and employ a retrograde metal lift-off process to form the asymmetric source/drain recesses. The lift-off process creates one recess which is off-set from a gate structure while a second recess is aligned with the structure. Thus, source/drain asymmetry is achieved by the physical structure of the source/drains, and not merely by ion implantation. The resulting non-planar device has a first channel of a fin contacting a substantially undoped area on the drain side and a doped area on the source side, thus the first channel is asymmetric. A channel on atop surface of a fin is symmetric because it contacts doped areas on both the drain and source sides.
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