MODELING THE DEGRADATION IN THE SUBTHRESHOLD CHARACTERISTICS OF SUBMICROMETER LDD PMOSFETS UNDER HOT-CARRIER STRESSING

Hot-carrier injection is observed increasingly to degrade the subthres hold characteristics with the scaling of LDD PMOSFETs. A physical subt hreshold current model is applied to the fresh and hot-carrier-stresse d submicrometre channel length devices, The channel length reduction i s subsequently extracted. An empirical relationship is developed to ch aracterize the degradation parameters as a function of stress time and channel length. With the use of this relationship, we can determine t he device lifetime or predict the minimum allowable channel length (fo r a certain percentage of degradation and lifetime) that is applicable for a specific technology. The degradation of the PMOSFET subthreshol d current, which imposes a major limit on device reliability for deep- submicron technology and low-power applications, is fully described by a physical analytical model.