100 mm GaN-on-SiC RF MMIC technology

Abstract

100 mm diameter 4H-SiC High Purity Semi-insulating substrates are now being manufactured in high volume. GaN HEMT layers grown on 100 mm SiC substrates have shown excellent sheet resistivity and AlGaN thickness uniformities (σ/mean) of 1.3 and 1.1%, respectively. The fabrication process for MMIC manufacture was adapted to the larger diameter substrates without requiring any change to the process design kits for the foundry. MIM capacitor processes were optimized, and resistor process, wafer thinning and slot via etching were all adapted to the larger platform. These 100 mm wafers are now being used in high volume production of both high power discrete GaN devices, as well as MMICs. Commercially available MMICs have been released to production using this 100 mm platform. A wide band 25 Watt power amplifier is discussed, along with a 3 watt driver capable of DC-4 GHz operation.