Materials Processing and Device Development to Achieve Integration of Low Defect Density III Nitride Based Radio Frequency

摘要

Gallium nitride HEMTs were successfully fabricated and tested on silicon substrates. Gallium nitride HEMTs produced on Si substrates had normal current voltage characteristics; however, the transconductance and saturation current density were low. It is believed that this is due to the fact that the GaN epi layers were not optimized on the initial wafer runs. These initial results validate that GaN HEMTs can be produced on low cost silicon substrates and support the position that continued funding in this area will lead to improved performance that may provide a better performance/cost ratio than GaN devices on more expensive substrates such as SiC and sapphire. Other accomplishments include construction and commissioning of a proprietary 100-mm III-Nitride MOVPE system specifically designed to address the uniformity issues required for commercial applications, development of a process route for the growth of GaN on Si(111), demonstration of growth of GaN on 50-mm and 100-mm diameter Si(1 11) substrates, and the first demonstration of a GaN-based high electron mobility transistor on a 100-mm platform.