Hot-carrier degraded SiGe/Si-hetero-pMOSFETs have been characterized. The degradation of transconductance and the threshold voltage shift after hot-carrier stress are discussed based upon the changes in the densities of SiGe/Si hetero-interface traps and gate-oxide interface traps, which have been evaluated using a unique low-temperature charge-pumping method. It is concluded that the increase in the maximum transconductance and the threshold-voltage shift after a hot carrier stress are mainly due to trapped electrons in the gate oxide near the drain, and the decrease in transconductance, dependent on the gate voltage, is considered to be due to generated SiGe/Si hetero-interface traps.
- Hot carrier effects
- Metal oxide semiconductor (MOS) devices
- Silicon germanium