Polarization Recovery Behavior of Hf0.5Zr0.5O2 on Gallium Nitride HEMT Heterostructures

Abstract

Ferroelectric (FE) devices have attracted much attention with potential application to a wide range of uses, including memory, steep slope transistors, and neuromorphic computing [1]–[2]. These studies [3]–[4] have primarily focused on the FE properties obtained on silicon substrates, and thus provide limited insight into the FE behavior that can be expected on other materials such as GaN. In contrast to traditional oxide and nitride dielectrics used in GaN MISHEMTs, FE materials have strong polarization effects that can be used to augment polarization engineering of 2D-electron gases (2DEGs) and threshold voltage control in GaN based transistors. In this work, the ferroelectric polarization switching behavior of Hf0.5Z0.5O2(HZO) on AIGaN/GaN HEMT structures is discussed. Significant ferroelectric polarization switching as well as distinct polarization recovery behavior have been observed for both metal-ferroelectric-semiconductor (MFS) and metal-ferroelectric-oxide-semiconductor (MFOS) devices. These results have significant implications for the devices design exploiting FE effects in GaN and related materials.