Comparative Study of III-Nitride Nano-HEMTs on Different Substrates for Emerging High-Power Nanoelectronics and Millimetre Wave Applications

We have investigated the performance characteristics of a III-nitride high electron mobility transistor (HEMT) on different substrates. It exhibits a negative threshold voltage (depletion mode) for a HEMT grown on silicon (Si), silicon carbide (SiC), and sapphire substrates, whereas it shows a positive threshold voltage (enhancement mode) when grown on beta-gallium oxide (beta-Ga2O3). Compared to Si, SiC, and sapphire, beta-Ga2O3 improves different parameters, such as off-state leakage characteristics, subthreshold voltage, breakdown voltage (V-BR), and radio frequency (RF) performance. In addition, it shows breakdown voltage characteristics of 4 V, 11 V, 94 V, and 108 V for a HEMT grown on Si, sapphire, SiC, and beta-Ga2O3 , respectively. It also exhibits cut-off frequencies of 122 GHz, 342 GHz, 380 GHz, and 420 GHz for HEMT using Si, sapphire, SiC, and beta-Ga2O3 substrates, respectively. Generally, HEMTs suffer from a trade-off between breakdown voltage and frequency characteristics. However, the proposed III-nitride HEMT developed on beta-Ga2O3 demonstrated an improved breakdown voltage without affecting its high-frequency characteristics. This achievement is mainly because of a better lattice match between the buffer material and the substrate. This research aims to provide a comprehensive understanding of a III-nitride nano-HEMT developed on a beta-Ga2O3 substrate in order to aid future research in this cutting-edge technology.

Automated summary

We investigated the performance of a III-nitride high electron mobility transistor (HEMT) on different substrates. A positive threshold voltage was found in HEMTs grown on beta-gallium oxide (beta-Ga2O3), while a negative threshold voltage was observed for HEMTs grown on silicon (Si), silicon carbide (SiC), and sapphire. Compared to Si, SiC, and sapphire, beta-Ga2O3 demonstrated improved parameters such as leakage characteristics, subthreshold voltage, breakdown voltage, and radio frequency performance. The research aims to provide a comprehensive understanding of a III-nitride nano-HEMT on a beta-Ga2O3 substrate, aiding future research in this advanced technology.