Superior n-MOSFET Performance by Optimal Stress Design

The high-performance n-FET is achieved by ultra- high-stress contact-etch-stop-layer stressor and optimal design of device dimensions. The biaxial-like stress resulting from a high symmetry in device dimension (gate width/gate length ratio is close to one) has the better performance in terms of I_on enhancement, ballistic efficiency, and injection velocity. The multichannel device with a smaller gate width/gate length ratio is proposed to enhance the device performance in the circuit design for the n-FET. The characteristics of the detailed stress simulation and the ballistic-transport measurement reported in this letter suggest that these results remain valid for ballistic-transport devices with 10-20-nm gate length. The stress distribution with different device dimensions was simulated by 3-D finite-element mechanical-stress simulation, and the mobility, ballistic efficiency, and injection velocity were calculated theoretically based on stress characteristics.