Negative bias temperature instability of carrier-transport enhanced pMOSFET with performance boosters

The effects of mobility boosters such as straining technologies and modified transport direction emerging for 65 nm pFET and beyond on negative bias temperature instability (NBTI) have been investigated. Although compressive silicon nitride film as contact etch stopper layer (CESL) increases the device performance of pFET, NBTI is degraded by excessive hydrogen from CESL depending on gate length and active width. In addition, induced mechanical strain in gate oxide plays an important role in NBTI degradation behavior. From NBTI on <100> p-channel transistor, it is found that NBTI is not influenced by channel direction and mobility change, but degraded by hydrogen incorporated CESL. Recessed SiGe source/drain (S/D) for high-performance pFET gives more resistant nature against NBTI degradation by elevated S/D structure even with compressive CESL containing high amount of hydrogen. The combination among performance booster for targeting device should be carefully balanced by considering performance gain and reliability