Review—Integration Methods of GaN and Diamond for Thermal Management Optimization
Fatima Zahrae Tijent, Mustapha Faqir, Hajar Chouiyakh, E. Essadiqi
Abstract
GaN high electron mobility transistor (HEMT) is a promising device for high-power and high-frequency applications thanks to its superior characteristics, such as high breakdown voltage, low on-state resistance, and high carrier mobility. However, its performance and reliability can become degraded due to a self-heating effect caused by the low thermal conductivity of conventional substrates. To improve performance, diamond is being increasingly deployed as a growth substrate for its high thermal conductivity, which enables efficient transportation of heat produced in the device channel toward the substrate. The direct growth of GaN on diamond is, however, challenging for many reasons, including the lattice and thermal expansion coefficient mismatch between the two materials. Accordingly, the development of suitable growth methods is required. Here we review the current techniques used in the integration of GaN and diamond.