Investigation of Breakdown in Vertical E-Mode Ga2O3 MOSFET with Different Structural Parameters

Abstract

In order to control drain-induced barrier lowering (DIBL) and thus premature breakdown in enhancement-mode (E-mode) Ga2O3 MOSFETs, the effect of structure and process parameters on the breakdown voltage (VBK) and DIBL is systematically investigated. The results show that the small gate work function, the small oxide dielectric constant, the thick oxide thickness, the excessive doping concentration of the epitaxial layer, and the wide and short channel will lead to a severe DIBL effect, causing the device to breakdown prematurely. On the other hand, the thickness of the drift region has a marginal effect on the DIBL, and after excluding other structural parameters that generate a strong DIBL effect, a reasonable increase in the thickness of the drift region is beneficial to improve the VBK of devices. This study can contribute to the design of Ga2O3 MOSFETs in the application scenario with high VBK reliability requirements.