High-breakdown voltage field-plated normally-off AlGaN/GaN HEMTs for power management

Abstract

The high breakdown voltage AlGaN/GaN HEMTs with source-terminated field plate was firstly fabricated for high frequency and high power application, employing by CF 4 plasma treatment for enhancement-mode (E-mode). The results showed that by adding the distance of gate to drain, L GD from 5 um to 15um, the breakdown voltage of the device was rapidly increased 350V, whose value is from 50V to 400V while the threshold voltage of the device, V TH was +0.5V by the charge modulation technology of CF 4 plasma. When the distance of source-terminated field plate, L FP was about 3um, the breakdown voltage of the device was apparently improved because the electric field near the gate edge was effectively shielded. The breakdown voltage and the specific on-resistance for the L GD and L FP distance of the device about 15um and 3um were about 475V and about 2.9 m Ω · cm2 respectively. The results from RF measurement showed that with the variation of V GS , the f T and f MAX parameters of the device with source-terminated field plate were the order of Gigahertz frequency. The DC, AC and transient characteristics of E-mode Power AlGaN/GaN HEMTs were satisfied and its forward current was about 90 mA. Therefore the E-mode AlGaN/GaN HEMTs was very suitable as the novel power switch technology in energy management application.