Temperature based analysis of 3-step field plate AlGaN/GaN HEMT using numerical simulation
Neha, Vandana Kumari, Mridula Gupta and Manoj Saxena
In this work, temperature based instability of the 3-step field plate (FP) AlGaN/GaN HEMT has been explored using ATLAS TCAD. DC performance characteristics such as: drain current, trans-conductance and I on/I off ratio at different temperatures (ranging from 300 K to 500 K) and GaN channel thicknesses (from 150 nm to 500 nm) have been investigated. It has been observed that, drain current decreases with rise in temperature with a coefficient of approximately −0.0031 mA μm−1 K−1. Subsequently, impact of temperature on breakdown voltage, electric field, electron temperature and parasitic capacitances has also been investigated. Enhancement in breakdown voltage and reduction in trans-conductance has been observed with rise in temperature for above zero temperature coefficient bias point. Along with temperature variation, impact of GaN channel, AlGaN barrier thickness and mole fraction of aluminium concentration has also been studied and it is seen that breakdown voltage and I on/I off increases for thinner channel and barrier thickness.