Device reliability and optimization on halo MOSFETs

In this work, hot carrier degradation behavior of the halo doped MOSFETs is investigated and an optimized halo design, taking into account the hot carrier reliability, is proposed. Conventional LDD MOSFETs and halo MOSFETs with the variations in LDD n- dose and halo dose are fabricated. The degradations of the threshold voltage and the drain saturation current under hot carrier stress (DAHC and CHC) conditions are measured and analyzed. Device simulations are also carried out covering a wider range than the experiments. In order to obtain the improved device characteristics in reliability as well as performance, the halo design should be carefully optimized.