Negative bias temperature instability characteristics of strained SiGe pMOSFETs

Investigation of the negative bias temperature instability (NBTI) mechanism of a strained Si_0.7Ge_0.3 pMOSFET with 30 nm tetraetho oxysilane (TEOS) oxide is presented. Because the carriers are confined in the buried SiGe channel, less threshold voltage shift and smaller drain current degradation are found in a strained SiGe pMOSFET compared to the Si control counterpart. Further, data of thermal active energy (Ea) are in agreement with the reaction-diffusion model. Our findings reveal that the strained Si_0.7Ge_0.3 pMOSFET has improved electrical properties and NBTI immunity because of less drain current degradation, less threshold voltage shift and longer lifetime.