RF reliability of short channel NMOS devices

The complexities associated with performing accurate large-signal measurements have been prohibitive in determining device level reliability under RF stress. In this work, a large-signal measurement setup is adapted to perform RF stress measurements on a 45 nm n-channel metal-oxide semiconductor transistor. The setup measures impedances and RF stress voltages under large-signal conditions at the measurement reference planes. This allows an accurate definition of applied stress conditions. A method to determine the lifetime of a device under RF stress is presented. The technique relates applied stress voltage to degradation of device characteristics. Channel hot-electron stress is applied to a device and degradation is measured over time. The device lifetime is determined by observing degradation of the saturation drain current. The results demonstrate the margin of improvement offered when a device is subjected to RF stress as compared to DC stress.