Silicon-packaged GaN power HEMTs with integrated heat spreaders

Abstract

We present the fabrication and experimental characterization of wafer-level-packaged GaN power HEMTs incorporating embedded copper thermal heat spreader and microfabricated interconnects for GaN-based RF front-ends. The packaging fabrication technology mainly relies on silicon micromachining, metal electroplating, and thermocompression bonding. The presented packaging approach simultaneously addresses thermal management, electrical interconnects, performance, and has size and cost advantages over conventional assembly approaches. Silicon-packaged GaN-on-SiC power switches with slanted field plate technology demonstrated comparable DC IV characteristics with on-wafer measurements (threshold voltage = 0.3 V, static on-resistance = 2 Ω.mm measured at gate bias voltage of 1.5V, and drain and gate leakage current < 10−6 A/mm at gate bias voltage of −2 V). The performance results of Si-packaged GaN devices were consistent with on-wafer measurements, indicating compatibility of the packaging technology with GaN power HEMTs.