Silicon super junction and silicon-carbide power devices are usually of a vertical structure, as shown here. Current flow is from the drain to the source region and traverses vertically through the device. GaN power devices on the other hand are lateral-structure. Current flows horizontally from drain to the source region in the two-dimensional electron gas (2DEG) region. Comparison of various performance between GaN and Si and SiC is summarized in the table here. GaN HEMT devices are superior for high-speed switching operation and have much lower figure of merit (FOM) numbers for ON-resistance (R_ON) x gate-charge (Qg). GaN HEMT devices have very small switching losses due to not having any reverse recovery losses from the body diode. Finally, GaN HEMT devices are usually called a high electron mobility transistor (HEMT). However, GaN power devices are currently only available up to a 650 V rating, while devices up to 1,000 V and above 1,000 V are available for silicon super junction and SiC MOSFETs, respectively.