Channel-length-independent hot-carrier degradation in analog p-MOS operation

The hot-carrier degradation of p-MOSFETs in analog operation is investigated. In accordance with analog operation requirements, the damage is characterized by the drain conductance and the data are taken from devices with channel lengths between 1 and 10 mu m. In the important saturation range, a strong channel-length-independent degradation of the drain conductance is found. This result is explained by a simple analytic model. Other parameters such as the drain current or the transconductance show the usual channel length dependence. These results show that an increase in channel length does not generally solve problems related with hot-carrier degradation. Furthermore, the common digital hot-carrier constraints are shown to be insufficient to cover analog applications.<>