Research On Hot Carriers Effect Of Uniaxial Strained Si NMOS

Due to higher carrier mobility and technology compatible with bulk Si, Strained Simaterial has become a hot spots in research in the modern semiconductor industry. Butdue to narrower band gap and higher carrier mobility, hot carrier effect is moresignificant in the strained Si MOS. Strained Si MOS device reliability issues havebecome a bottleneck of its development.Based on the analysis on the basic physical properties, the stress introducedmechanism and basic structures of strained Si, the hot carrier effect of uniaxial strainedSi NMOS is focused. Firstly, this paper analyze the hot carrier generation mechanismeffects in uniaxial strained Si NMOS. The hot carrier effects on the uniaxial strained SiNMOS’s interface characteristics are analyzed, and establish the threshold voltage shiftmodel, interface states are added into the model, the model was simulated using Matlab,and using Silvaco TCAD to verify. Then, the degradation mechanism of hot carrierinduced uniaxial strained Si NMOS’s DC characteristics are studied, establish substratecurrent, drain current and subthreshold swing degradation model, these models weresimulated using Matlab, and using Silvaco software simulation results show that it agreewith models. Finally, the degradation mechanism of hot carrier-induced uniaxialstrained Si NMOS’s AC characteristics are researched, establish cutoff frequency andnoise figure degradation model, and using software to validate the model, the researchresults show that hot carrier effects generate the interface states will lead to thedegradation of device’s AC characteristics. The results of this study provides theoreticalbasis for the reliability of uniaxial strained Si devices.