Resonances on GaN-on-Si Epitaxies: A Source of Output Capacitance Losses in Power HEMTs

GaN-on-Si high-electron-mobility transistors (HEMTs) exhibit excellent properties for efficient power conversion. Nevertheless, a considerable energy loss associated with the charging and discharging of output capacitance ( C OSS ) in these severely limits their application at high switching frequencies. In this work we report observation unexpected resonances HEMTs. These high-frequency lead to losses fast during transients. We propose simple wafer-level measurement technique evaluate such epitaxy level, prior transistor fabrication. Experimental results from revealed that Silicon substrate is main origin losses. Such evaluation xmlns:xlink="http://www.w3.org/1999/xlink"> OSS opens opportunities characterize optimize epitaxies future devices, especially those operating