Applicability of Field Plate in Double Channel GaN HEMT for Radio-Frequency and Power-Electronic Applications

In the present communication, for the first time, applicability of Field Plate (FP) for Double Channel (DC) AlGaN/GaNHEMT is demonstrated. Impact of design space parameters such as field plate length (LFP) and Silicon Nitride thickness (tSiN) on breakdown voltage of DC HEMT is investigated and benchmarked with Single Channel (SC) HEMT. The investigation is carried out using ATLAS Technological Computer Aided Design (TCAD) Simulation tool, which is an efficient method in terms of time and cost to analyze and understand DC HEMT prior to the fabrication. The simulation shows new findings that breakdown voltage of DC device exhibited a large deviation with that of SC device. The breakdown voltage deviation is well corroborated through electric field, impact ionization and off-state leakage analysis. The electric field analysis has shown optimal value of LFP and tSiN for DC HEMT. It is also observed that tSiN for DC-HEMT should be lower than that of SC-HEMT. In this paper, the off-state leakage, electron-depletion and impact ionization are the first-hand observations for benchmarking DC device with SC device. Furthermore, it is found that DC device yield higher cut-off frequency and device linearity than that of SC device, which is highly desirable for Radio-Frequency (RF) and linear amplifiers. Thus, the observation presented in this paper assist device technologist to enhance the performance of DC device further and foundries to optimize the FP for DC device.