Study on gate oxide thickness dependence of hot carrier induced degradation for n-MOSFETs.

The mechanism of reduced hot-carrier-induced degradation in the thinner oxide MOSFET is not clear. The possible causes for reduced degradation might be that (1) hot carrier trapping rate is smaller, (2) the channel conductance is larger due to the larger inversion charges, and/or (3) mobility degradation is smaller. Hot-carrier-reduced degradation in a sub-10-nm gate oxide n-MOSFET is investigated and the gate oxide thickness dependence is explained. It is experimentally shown that the (1) is not pertinent. It is demonstrated that the drain current degradation can be modeled quantitatively by a simple model including the effect of both (2) and (3). It is found that the effect of (2) is minor and the (3) is the primary factor.