表面态对GaN HEMT电流崩塌效应影响的研究

Research of the Impact of the Surface States on the Current Collapse of the GaN HEMTs

针对GaN HEMT电流崩塌物理效应,测试了各种条件下器件I-V特性。发现在栅脉冲条件下器件最大漏输出电流减小了23.8%,且随着栅脉冲宽度减小或周期增大而下降,并且获得了其输出电流与脉冲宽度W和周期T的定量关系;在漏脉冲测试条件下,器件输出电流有所增大,并随着脉冲宽度减小而缓慢增大。实验结果,可用器件栅漏之间表面态充放电的原理来解释所观察到的测试现象和电流崩塌物理。

Aiming at the current collapse physical effect of the GaN HEMT, the device I-V properties were measured under various conditions. It is found that under gate pulse condition, the maximum drain current decreased about 23.8%, furthermore, the drain current reduced when the pulse width decreased or the pulse period increased. The ration relationship between its output current and the pulse width W ＆ period T was obtained. Simultaneously, under the drain pulse testing condition, the device output current was increasing, and it is continuously increasing with the decreasing of the pulse width. The experiment results show that the testing phenomenon and the cause of the current collapse can be explained by the principle of the surface state charging and discharging between the gate and the drain of the devices.