New Field Stopper Process to Strengthen Double MESA-GLASS AC Switches' Reliability During Rugged Application Environments
Résumé
This paper deals with the introduction of a highly doped N-type diffusion, called field stopper, in the bottom of each peripheral groove of double MESA-GLASS AC switch (e.g. Triac) to strengthen its reliability in more severe applications. From a set of high temperature and reverse bias (HTRB) tests, this new process flow allows multiplying the device lifetime by 11.3 compared to standard products when junction temperature and bias are fixed to 150 °C and 800 V AC respectively. An empirical acceleration model is proposed. This model is characterized by activation energy and voltage constant about 0.48 eV and 6.7 mV-1, respectively. Finally, we suggest that ionic conduction through the molding compound is the main physical phenomenon involved in the double MESA-GLASS AC switch aging.