Hot electron-induced MOS transconductance degradation

This work studies both the temperature and bias dependent transconductance degradation due to hot electron stressing in n-channel MOS transistors. Thermal oxide (OX), nitrided oxide (NOX), and nitrogen-annealed nitrided oxide (NNOX) are used as the device gate dielectrics. Results show that NOX device has the smallest transconductance degradation (<3%) at room temperature and NNOX has the largest degradation (>20%) at 200 K because of the large amount of electrons being captured by the shallow traps and large Fuchs parameter for coulomb scattering. We also found that the temperature dependence and the hot-electron fluence effect of the transconductance degradation can be correlated with the hot electron-induced threshold-voltage shift. However, for electric field dependence, it is governed by the scattering parameters as well.