New layout dependency in high-k/Metal Gate MOSFETs

Abstract

We report a new N/PFET Gate Patterning Boundary Proximity layout dependent effect in high-k dielectric/Metal Gate (HK/MG) MOSFETs which causes anomalous threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> ) modulation for the first time. We investigated the mechanism by using special test structures and process optimizations to suppress this layout dependency. Finally, we achieved the best over all process optimization which makes it possible to suppress layout dependency without degrading FET performance/yield/reliability.