F等离子体处理 AlGaN/GaN HEMT击穿电压和电流崩塌研究

F等离子体处理工艺被广泛的应用于 AlGaN/GaN HEMT增强型器件的研制和栅前处理工艺。本文研究了低功率F处理 AlGaN/GaN HEMT的击穿特性和电流崩塌特性。随着F处理时间的增加，饱和电流下降，阈值电压正向移动。对不同F处理时间的器件肖特基特性分析后发现，120s的F处理后器件栅泄漏电流明显减小，器件击穿电压提高，当F处理时间大于120s后，由于长时间F处理带来的损伤器件栅泄漏电流没有继续减小。采用不同偏置下的双脉冲测试对不同F处理时间的电流崩塌特性进行了研究，低功率F处理后没有发现明显的电流崩塌现象。

Breakdown voltage and current collapse of F-plasma treated AlGaN/GaN HEMTs

The breakdown and the current collapse characteristics of high electron mobility transistors (HEMTs) with a low power F-plasma treatment process are investigated. With the increase of F-plasma treatment time, the saturation current decreases, and the threshold voltage shifts to the positive slightly. Through analysis of the Schottky characteristics of the devices with different F-plasma treatment times, it was found that an optimal F-plasma treatment time of 120 s obviously reduced the gate reverse leakage current and improved the breakdown voltage of the devices, but longer F-plasma treatment time than 120 s did not reduce gate reverse leakage current due to plasma damage. The current collapse characteristics of the HEMTs with F-plasma treatment were evaluated by dual pulse measurement at different bias voltages and no obvious deterioration of current collapse were found after low power F-plasma treatment.