Frequency response of stress-effects on CMOS power amplifiers

RF Power Amplifiers (PAs) undergo to high electrical stress conditions due to strong lateral field along the channel. Reliability of CMOS PAs is largely studied in literature. Generally is focused in understanding how RF stress can harm the device. Many authors proved that the generation of defects does not have a frequency dependency. In this work the problem is faced from a new point of view. The response of the defects, instead of the generation, is studied over frequency. It is demonstrated that the electrons-trapping by interface states is quenched by increasing the operation frequency. As a consequence the performance of the PA are recovered. This finding points out for the first time the possibility of relaxing the reliability constrains when operating in RF regime.