Improved breakdown characteristics of monolithically integrated III-nitride HEMT–LED devices using carbon doping

•Selective growth of AlGaN/GaN HEMTs on LEDs for monolithic integration.•Improve breakdown characteristics of HEMTs on LEDs by carbon doping.•No degradation of HEMT DC performance by carbon doping.•Carbon incorporation efficiency well controlled by growth parameters.

We report selective growth of AlGaN/GaN high electron mobility transistors (HEMTs) on InGaN/GaN light emitting diodes (LEDs) for monolithic integration of III-nitride HEMT and LED devices (HEMT–LED). To improve the breakdown characteristics of the integrated HEMT–LED devices, carbon doping was introduced in the HEMT buffer by controlling the growth pressure and V/III ratio. The breakdown voltage of the fabricated HEMTs grown on LEDs was enhanced, without degradation of the HEMT DC performance. The improved breakdown characteristics can be attributed to better isolation of the HEMT from the underlying conductive p-GaN layer of the LED structure.