Research On Hot-carrier Of Strained-si MOSFET

As the device continues to decrease,scaling down technology is gradually getting close to its physical limits. Along with the restriction of its increasing economic cost, the actual benefit is a continued downward trend. By inducing the strain to the traditional bulk silicon device, strained silicon technology improve the restriction of the mobility on the device performance. Being compatible with bulk silicon technology, strained silicon MOSFETs have been widely used to extend Moore's Law. However, reliability problems on strained silicon devices are getting more and more important.Based on the analysis on the basic physical properties, device types and basic structures of strained silicon, the hot carrier effect of biaxial strained silicon MOSFET is focused. Firstly, this paper analyzes the hot carrier generation mechanism effects and its caused failure mechanism, establishes the substrate current model, which reflects the effects of hot carrier, and simulates to analyze the impact of the gate length, gate oxide thickness, source and drain junction depth, and some other parameters on the substrate current. Then, by simulating the impact of the hot carrier effect on the transfer characteristics of the strained silicon MOSFET, threshold voltage and some other transconductance parameters'degradation caused by hot carrier effect is analyzed. Finally, LDD structure, which can improve the strained silicon MOSFET hot carrier effect, has been demonstrated. Analysis and research have been made to the mechanism that LDD structure can prevent the hot carrier effect. Meanwhile, simulation and comparison of the substrate current, the transfer characteristics and the output characteristics of the LDD structure strained silicon MOSFET to those of the general structure strained silicon MOSFET, by using the ISE.TCAD10.0 software. The simulation results show that the LDD structure does improve the hot carrier effect of the strained silicon MOSFET.