Enhancement-Mode AlGaN/GaN Fin-MOSHEMTs on Si Substrate With Atomic Layer Epitaxy MgCaO

摘要

We have demonstrated high-performance enhancement-mode or normally-off AlGaN/GaN fin-MOSHEMTs on a Si substrate with various fin width of 100–210 nm using atomic layer epitaxy (ALE) MgCaO as the gate dielectric. Through the fixed negative charges in MgCaO depleting the channel at the fin sidewalls, in contrast to the usual positive charges in atomic layer deposited amorphous AlO, the threshold voltage ( ) is positively shifted and normally-off device is realized. A high maximum drain current ( ) of 670 mA/mm, high on/off ratio of 10 ~ 10, and of 1 V have been achieved on the device. Combining with negligible – hysteresis of 30 mV and current collapse, the ALE MgCaO fin-MOSHEMT turns out to be a promising candidate for the future GaN power device applications.