Epiwafer foundry and substrate maker IQE plc of Cardiff, Wales, UK has launched gallium nitride (GaN)-based high-electron-mobility transistor (HEMT) epitaxial wafers on 150mm-diameter semi-insulating silicon carbide (SiC) substrates supplied by the WBG Materials subsidiary in Pine Brook, NJ, USA of II-VI Inc, a provider of engineering materials and optoelectronic components.
GaN power amplifiers offer superior power capability, efficiency, bandwidth and linearity compared with silicon (Si) or gallium arsenide (GaAs)-based technologies commonly used, providing benefits in terms of both higher performance and lower overall system costs.
GaN-based low-noise amplifiers (LNAs) exhibit improved robustness, noise figure and dynamic range compared with incumbent solutions, the firms say. In addition, GaN-based transistors can operate at high temperatures, reducing system cost, size and weight. They are hence now established as a new technology for a wide range of defence applications, the firms add.
The introduction of 150mm GaN HEMT epiwafer products also enables cost reduction, customers’ production capacity and yield improvement, as well as the potential for insertion into a wider range of chip fabrication facilities, it is reckoned. To date, the commercial market penetration of GaN HEMTs has been limited by the higher cost of epitaxial material grown on 100mm SiC substrates.
GaN HEMT fabrication using LDMOS (laterally diffused metal oxide semiconductor) process lines has been demonstrated by IQE’s customers, and the firm’s 150mm products are compatible with existing LDMOS processing lines that have been made available as a result of the silicon industry’s transition to 200mm technology.
“Scaling up to 150mm wafer diameter is a critical milestone on the path to technological maturity and wide market acceptance of GaN HEMTs on SiC,” says Russ Wagner, VP of IQE’s Wireless business unit. “IQE has established an industry-leading position by offering a full range of GaN-based high-power RF transistor wafers in formats that enable the most cost-effective processing and system designs,” he adds. “We are very pleased with the quality of substrates supplied by II-VI Inc and look forward to continuing our partnership as we execute volume production ramp and expand IQE’s range of advanced high-power high-frequency transistor products for defense and wireless infrastructure applications,” Wagner comments.
“The WBG Materials subsidiary of II-VI Inc has developed high-quality 4H - 150mm SiC substrates, for both the RF and power markets,” says Dr Tom Anderson, general manager of II-VI subsidiary WBG Materials. “These 150mm SiC substrates will greatly reduce device costs by increasing the number of devices produced per wafer, enabling 150mm wafers to be processed using modern, high-volume semiconductor tools designed for large wafers and by providing competitive sourcing and leveraging of high volumes into commercial markets,” he adds. “Our partnership with IQE in this 150mm product development has enabled rapid technology advances for both groups and we are looking forward to continuing our work together to deliver this state-of-the-art product to our joint end users.”
