Enhanced breakdown voltage of Si-GaN monolithic heterogeneous integrated Cascode FETs by the device structure design

摘要

In this work, the factors affecting the breakdown voltage of Si-GaN monolithic heterogeneous integrated Casccode FET fabricated by transfer printing were investigated. These two factors are the avalanche breakdown resistance of the Si device and the thickness of SiN electrical isolation layer. Two kinds of device structures, Si MOSFET and Si laterally-diffused MOSFET (LDMOSFET), were designed to study the effect of the avalanche breakdown resistance of the Si devices on the breakdown characteristics of Cascode FET. The effect of the thickness of SiN electrical isolation layer was analyzed. Finally, the breakdown voltage of monolithic integrated Cascode FET reached 770 V.