On The Role of Stress Engineering of Surface Passivation in Determining the Device Performance of AlGaN/GaN HEMTs

In this work, we report an improvement in the device's threshold voltage, off-state voltage handling capability, and dynamic ON resistance behavior with stress engineering in the passivation layer. Engineering the passivation stress to a higher compressive value, resulted in a 500mV positive V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf> shift, enhanced DC breakdown voltage by 105V, and reduced dynamic ON resistance from ~1000 % to ~12%. Detailed electroluminescence and thermo-reflectance analysis established the observed improvement in dynamic ON resistance to be caused by the modulation of channel electric field due to intrinsic stress in the passivation layer.