Design of AlGaN/GaN HEMT Device with InGaN Back Barrier for RF Applications

This paper reports a double hetero-junction AlGaN/GaN/InGaN HEMT. A 3nm layer of InGaN is introduced in a conventional AlGaN/GaN HEMT structure. Considering both the proposed HEMT structure and conventional HEMT a performance comparison and detailed analysis is done. A potential barrier is created as a result of InGaN layer insertion leading to improved 2DEG carrier confinement. This in turn leads to enhanced DC and RF performance of the device. Better carrier confinement in the quantum well will result in high drain current and transconductance eventually leading to high frequency performance. The proposed device reported a drain current of 450mA/mm and transconductance of 200mS/mm at Vds=2V. The RF characteristics reported a cut-off frequency of 25GHz. The additional potential barrier, created at the InGaN/GaN hetro-junction, improves the modulation efficiency of the channel carriers which leads to minimization of gate leakage current and spilling over of 2DEG carriers into the buffer region. This is reflected in the low noise figure of the reported device. This enhances the device’s performance in terms of DC and RF characteristics thus making it a suitable candidate for RF applications.