Improving breakdown voltage for double-channel AIGaN/GaN HEMTs with slant field-plate

In this study, double-channel AlGaN/GaN high electron mobility transistors are designed with a slant gate field plate to improve the device breakdown voltage. Sentaurus TCAD is used for device simulation. At the first stage, the slant gate field plate is compared with a regular gate field plate to study the reduction of the peak electric field at the gate edge. It is found that the slant gate field plate is more effective in reducing the peak electric field, and is therefore more beneficial for breakdown voltage. At the second stage, the length of the slant gate field plate is optimized to further improve the breakdown voltage. Simulation result shows that an optimized slant gate field plate improves the breakdown voltage by up to 357 V, while specific on-resistance is increased by only 0.38%. This indicates that an optimized slant gate field plate is a good solution to improve the breakdown voltage.