Analysis of On-Resistance in 650-V Enhancement-Mode Active-Passivation p-GaN Gate HEMT

This work investigates the resistance distribution of the E-mode GaN-on-Si active-passivation (AP) p-GaN gate high-electron- mobility transistor (HEMT) using the transfer length method (TLM). The AP-HEMT has a unique active-passivation layer that is electrically connected to the p-GaN gate and covers most area of the device. The active-passivation layer changes the way the 2DEG is generated in the device, so the constitution of the device R ON is expected to differ from the conventional p-GaN gate HEMT (Conv-HEMT). According to our study, the sheet resistance of the 2DEG under the active-passivation layer is lower than that of the access region, leading to the reduced R ON in AP-HEMT compared to Conv-HEMT. The temperature dependence of the resistance is also investigated. Additionally, AP-HEMT exhibits an improved reverse conduction performance across the temperature range of 25 degrees C to 150 degrees C, due to the reduced gate-to-drain resistance in the device.