Leakage current effects on N-MOSFETs after thermal ageing in pulsed life tests

This paper presents a synthesis of leakage current effects on N-MOSFET performances, after thermal ageing in pulsed life tests. A 3000h pulsed RF life test has been conducted on a dedicated RF S-band bench in operating modes. It is interesting to understand the degradation mechanism effects caused by the increase leakage current and in turn on drifts of critical parameters. It shows with tracking of a set of RF parameters (Pout, Gain and Drain Efficiency: DE) that only Hot Carrier Injection (HCI) phenomenon appears with incidence on RF. It is the main cause for device degradation leading to the interface state generation (traps), which results in a build up of negative charge at Si/SiO2 interface. The physical processes responsible for the observed degradation at different stress conditions are studied by means of 2D ATLAS-SILVACO simulations to locate and confirm these phenomena.