Investigation of Traps Impact on PAE and Linearity of AlGaN/GaN HEMTs Relying on a Combined TCAD–Compact Model Approach

This article proposes a novel modeling approach for the analysis of the microwave power performance of GaN HEMTs. By combining Technology Computer-Aided Design (TCAD) physical and circuit design standard compact trap models, surface and buffer traps can be directly correlated, for the first time, with power-added efficiency (PAE) and output power ( $\textit{P}_\text{out}$ ). A new trap model topology is created with an RC subnetwork and nonlinear scaling functions, encouraged by TCAD analysis on trap localization. The effects of surface trapping were quantified using a TCAD-based extraction of the proposed trap model, observing a loss on $\textit{P}_\text{out}$ of 3 dBm and a maximum PAE ( $\text{PAE}_\text{MAX}$ ) loss of 12% due to surface traps. In addition, the correlation of 2-D electron gas (2DEG) at the drain access region with $\text{PAE}_\text{MAX}$ and the 1-dB compression point of $\textit{P}_\text{out}$ ( $\text{OP}_\text{1\,dB}$ ) is investigated and transformed into a correlation between the density of traps ( $\textit{N}_\text{T}$ ) and $\text{PAE}_\text{MAX}$ and $\text{OP}_\text{1\,dB}$ , creating a new direct method to connect TCAD with RF large-signal simulations.