GaN on Diamond HEMT for Gate Thermal Management

GaN based HEMTs are capable of achieving high power density at high frequency. Thus, solid-state high power amplifiers based on GaN will be smaller and lighter than incumbent technologies. The use of a silicon substrate for GaN HEMTs provides a reliable GaN device which is also economical. Discrete devices and MMICs based on GaN on Si are ideally suited for applications in high power radar modules for electronically scanned arrays (ESAs). The performance and reliability of GaN HEMTs is closely linked to the operating temperature. For this program, we will further develop a novel GaN on diamond HEMT structure with superior thermal conductivity relative to conventional approaches. In addition to significantly improving the thermal resistance, we will develop a novel process pathway that will be inherently manufacturable and cost effective thus enabling the maximum utilization of GaN technology in various military applications. In Phase I, we will demonstrate key features of the material structure and thermal modeling of the concept device design. In Phase II, we will advance the maturity of the concept through optimization of the process and demonstrating a functional GaN on diamond HEMT device tailored for ESA to evaluate the thermal and electrical performance.