GaN-on-Si Lateral Power Devices with Symmetric Vertical Leakage: The Impact of Floating Substrate

In a monolithically integrated GaN-on-Si chip with multiple devices, the conductive Si substrate is shared by all the devices. How to properly terminate the common Si substrate is of critical significance for the voltage blocking and dynamic performance. In this paper, the impact of the floating substrate on the current collapse of the lateral GaN-on-Si devices featuring symmetric vertical leakage has been investigated, which facilitates future evaluation of the dynamic performance of a monolithically integrated half-bridge. The floating substrate can provide enhanced breakdown voltage, alleviated buffer-related dynamic R-ON degradation, and can possibly suppress the cross-talk particularly for the devices with symmetric vertical leakage.