Correlation Between Electrical Performance and Gate Width of GaN-Based HEMTs

In this work, we comprehensively studied the correlation between the electrical characteristics and the gate width ( ${W}_{G}$ ) of GaN-based HEMTs. On the one hand, as ${W}_{G}$ is scaled down from 100 $\mu \text{m}$ down to $3~\mu \text{m}$ , the devices exhibit five-times-enhanced on-state drain current density and largely reduced on-resistance, thanks to the increased electron mobility and mitigated self-heating effects in the narrow- ${W}_{G}$ channels. On the other hand, the devices with a wider ${W}_{G}$ exhibit reduced off-state leakage current and enhanced breakdown voltage, thanks to a decreased electric field and increased Schottky barrier height. Further temperature-dependent characterization reveals that the ${W}_{G}$ -modulation behavior on both on- and off-state device properties is still effective at a high temperature of 150°C. These experimental results can provide a straightforward approach for effective channel modulation and device optimization of GaN-based power devices of the future.