Improving performance in single field plate power High Electron Mobility Transistors (HEMTs) based on AlGaN/GaN

In this paper we have investigated the effectiveness of employing the single field-plate (SFP) technique to enhance the breakdown voltage (BV) of AlGaN/GaN power high electron mobility transistors (HEMTs).A systematic procedure is provided for designing the SFP device, using two dimensional (2-D) simulation to obtain the maximum improvement in the drain-source current (I_DS) and to achieve maximum breakdown voltage. It is found that significantly higher breakdown voltages and I_DS can be achieved by just raising the thickness of the passivation layer Si₃N₄ beneath SFP (t) and raising SFP length (L_sfp) between the source and drain. We demonstrate that when a single field-plate connected to the source is employed, both breakdown voltage and I_DS can be enhanced by optimizing the passivation layer Si₃N₄ thickness beneath the SFP as well as the SFP geometry.