Investigation on the Impact of Gate Field Plate Structure on the Capacitance Characteristics of GaN-Based Power HEMT Device

The outstanding high-frequency characteristics of GaN materials have yet to be fully exploited, and issues related to capacitance properties and dynamic losses need to be addressed. This paper deconstructs the capacitance, providing clear definitions for device capacitance at various levels including device testing, packaging, and underlying structural materials. By taking the gate field plate length as a variable, it elucidates the impact mechanism of GaN power device structural parameters on capacitance characteristics. Furthermore, specific design recommendations for device structures are provided in response to losses in specific circuit topologies. These findings hold significant implications for guiding improvements in system efficiency and power density in high-frequency applications of GaN power devices.