Reliability of planar, Super-Junction and trench low voltage power MOSFETs

A strong demand of even more compact and reliable devices has powered in the last years the development of advanced power MOSFET structures. Among them, the planar STripFET (TM) has been introduced as an alternative to conventional trench gate MOSFET in low voltage (<60 V) applications. Moreover low voltage Super-Junction devices are also under development. In this paper a conventional trench gate MOSFET is compared in terms of reliability with a STripFET (TM) and a Super-Junction device. The comparison is accomplished through a reliability model taking advantage from a dynamic analysis of the temperature distribution over the metal source surface in an effort to correlate electric working conditions to thermo-mechanical stresses.