An investigation about the limitation of strained-Si technology

Strained-Si technology is the Holy Grail for present semiconductor industry and is used extensively to boost the device performance, recently. However, the limitation of strained-Si technology has greatly perplexed us and need to investigate in detail. In this work, the low temperature ballistic measurement enables us to discriminate the origin of mobility enhancement under stress from the reduction of effective mass and/or the influence of different scattering mechanisms. It is found that the electron mobility enhancement under stress will become less sensitive when the gate length of device reaches ~100 nm. The real mechanism of this phenomenon have be proved to the characteristic of device ballistic transport and the optimal stress design developed in this work can further extend the limitation of Strained-Si technology to the smaller gate length region (technology node) (Fig. 1).