面向P-GaN栅HEMT的物理基础紧凑模型：完整Q–VD与C–VD响应

P-GaN/AlGaN/GaN high electron mobility transistors (P-GaN HEMTs) are the most commercially promising candidates to achieve enhancement-mode (E-mode) GaN-based transistors, for which the development of a compact model is essential but challenging. Although the gate capacitance ( $\textit{C} _{\text {gg}}$ ) model of P-GaN HEMT based on the gate charge ( $\textit{Q} _{\text {g}}$ )–gate voltage ( $\textit{V} _{\text {G}}$ ) relationship has been well established, there is still a lack of research on the charge distribution inside the device as a function of the drain voltage ( $\textit{V} _{\text {D}}$ ), which leads to the inability to further divide the $\textit{C} _{\text {gg}}$ into gate–source capacitance ( $\textit{C} _{\text {gs}}$ ) and gate–drain capacitance ( $\textit{C} _{\text {gd}}$ ). In this work, a physics-based compact model for P-GaN HEMT is proposed to establish the complete charge and capacitance responses as a function of both $\textit{V} _{\text {G}}$ and $\textit{V} _{\text {D}}$ , including: 1) a model based on advanced SPICE model for HEMT (ASM-HEMT) is developed to derive the explicit expression of carrier concentration ( $\textit{n} _{\text {s}}$ ) in P-GaN HEMT; 2) an improved quasi-physical zone division (QPZD) model is proposed, which achieves modeling on the $\textit{Q} _{\text {g}}$ as a function of $\textit{V} _{\text {D}}$ and intrinsic capacitances $\textit{C} _{\text {gg}}$ , $\textit{C} _{\text {gs}}$ , and $\textit{C} _{\text {gd}}$ for depletion-mode (D-mode) HEMT; and 3) based on the model proposed in 2), a model suitable for calculating the $\textit{Q} _{\text {g}}$ variation with $\textit{V} _{\text {D}}$ in the $E$ -mode HEMT is further proposed, taking the special charge behaviors in the P-GaN HEMT structure into consideration. This work not only demonstrates the difference between $E$ -mode and D-mode HEMTs in terms of the dynamic changes in the internal physical properties when $\textit{V} _{\text {D}}$ is applied but also achieves the modeling of $\textit{C} _{\text {gs}}$ and $\textit{C} _{\text {gd}}$ of the P-GaN HEMT. The proposed capacitance model is verified with calibrated TCAD simulation results, with RMSE lower than 5%, indicating a high degree of agreement.