Effect of HTRB lifetest on AlGaN/GaN HEMTs under different voltages and temperatures stresses

Space and transport industries are facing a strong global competition which is setting economic constraints on the entire supply chain. In order to address decreasing development costs and to propose new features, components-off-the-shelf (COTS) have become a very attractive solution. This paper investigates the degradation of AlGaN/GaN HEMTs COTS submitted to HTRB lifetest. Temperature and voltage step stresses were applied to untangle the effect of each stressor. The main aim is to establish a lifetime model, taking into account several degradation mechanisms, over a large range of temperatures and voltages. The experimental outcomes highlight the activation of different failure mechanisms occurring during the stress tests, and which depend from the different temperature and voltage working ranges. In this work, experimental analysis has been performed in order to characterize the root cause behind the activation of these multiple failure mechanisms and estimate the operative range where they may superimpose.