Scalability of advanced partially depleted n-MOSFET devices on biaxial strained SOI substrates

Biaxial tensile strained substrates offer strong electron mobility enhancements resulting in large drive current gains. For short channel n-MOSFETs, however, these improvements diminish. Root causes for this performance degradation are investigated through experiments and simulations. Elastic stress relaxation arising from shallow trench isolation (STI) is found to be negligible for current state-of-the-art transistors. On the other hand, parasitic source/drain resistance seems to be responsible for the limitation of drain current gains in deeply scaled devices. This effect is even further aggravated by an increased parasitic source/drain resistance in sSOI devices compared to standard SOI.