MM-wave frequencies GaN-on-Si HEMTs and MMIC technology development

Gallium Nitride (GaN)-based High Electron Mobility Transistors (HEMTs) grown on Silicon (Si) substrates technology is emerging as one of the most promising candidates for cost effective, high-power, high-frequency Integrated Circuit (IC) applications; operating at Microwave and Millimetre (mm)-wave frequencies. To capitalise on the advantages of RF GaN technology grown on Low resistivity (LR) Si substrates; RF losses due to the Si substrate must be eliminated at the active devices, passive devices and interconnect. Low resistivity Si substrates are intrinsic prone to RF losses and high resistivity (HR) Si substrates shown to exhibit RF losses as a result of operating substrate temperature at the system level. Therefore, obtaining a viable high-performance RF GaN-on both LR and HR Si device remains a challenge for this technology. In an attempt to overcome these issues, Microwave Monolithic Integrated Circuit (MMIC)-compatible technology was developed for the first time aiming to eliminate the substrate coupling effect for the realisation of high performance passive and active devices on GaN-on-Si substrates for mm-wave MMIC applications